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The Project Gutenberg eBook of Nitro-Explosives: A Practical
Treatise
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Title: Nitro-Explosives: A Practical Treatise
Author: P. Gerald Sanford
Release date: March 10, 2005 [eBook #15308]
Most recently updated: December 14, 2020
Language: English
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*** START OF THE PROJECT GUTENBERG EBOOK NITRO-
EXPLOSIVES: A PRACTICAL TREATISE ***
Treatise
This eBook is for the use of anyone anywhere in the United States and most
other parts of the world at no cost and with almost no restrictions
whatsoever. You may copy it, give it away or re-use it under the terms of
the Project Gutenberg License included with this eBook or online at
www.gutenberg.org. If you are not located in the United States, you will
have to check the laws of the country where you are located before using
this eBook.
Title: Nitro-Explosives: A Practical Treatise
Author: P. Gerald Sanford
Release date: March 10, 2005 [eBook #15308]
Most recently updated: December 14, 2020
Language: English
Other information and formats: www.gutenberg.org/ebooks/15308
Credits: Produced by Case Western Reserve University Preservation
Department, Curtis Weyant, and the Online Distributed
Proofreading Team
*** START OF THE PROJECT GUTENBERG EBOOK NITRO-
EXPLOSIVES: A PRACTICAL TREATISE ***
Page 4
Produced by Case Western Reserve University Preservation
Department, Curtis Weyant, and the Online Distributed
Proofreading Team
NITRO-EXPLOSIVES
[Illustration: DANGER BUILDING SHOWING PROTECTING
MOUNDS. (See page 6.)]
NITRO-EXPLOSIVES
A PRACTICAL TREATISE
CONCERNING THE
PROPERTIES, MANUFACTURE, AND ANALYSIS OF NITRATED SUBSTANCES,
INCLUDING THE FULMINATES, SMOKELESS POWDERS, AND CELLULOID
BY
P. GERALD SANFORD, F.I.C., F.C.S.
Public Analyst to the Borough of Penzance; late Consulting Chemist to
the
Department, Curtis Weyant, and the Online Distributed
Proofreading Team
NITRO-EXPLOSIVES
[Illustration: DANGER BUILDING SHOWING PROTECTING
MOUNDS. (See page 6.)]
NITRO-EXPLOSIVES
A PRACTICAL TREATISE
CONCERNING THE
PROPERTIES, MANUFACTURE, AND ANALYSIS OF NITRATED SUBSTANCES,
INCLUDING THE FULMINATES, SMOKELESS POWDERS, AND CELLULOID
BY
P. GERALD SANFORD, F.I.C., F.C.S.
Public Analyst to the Borough of Penzance; late Consulting Chemist to
the
Page 5
Cotton Powder Company Limited; and formerly Resident Chemist at the
Stowmarket Works of the New Explosives Company Limited, and the Hayle
Works of the National Explosive Company Limited
~Second Edition, Revised and Enlarged~
PREFACE.
In compiling the following treatise, my aim has been to give a brief but
thoroughly practical account of the properties, manufacture, and methods of
analysis of the various nitro-explosives now so largely used for mining and
blasting purposes and as propulsive agents; and it is believed that the
account given of the manufacture of nitro-glycerine and of the gelatine
dynamites will be found more complete than in any similar work yet
published in this country.
For many of the facts and figures contained in the chapter on Smokeless
Powders I am indebted to (amongst others) the late Mr J.D. Dougall and
Messrs A.C. Ponsonby and H.M. Chapman, F.C.S.; and for details with
regard to Roburite to Messrs H.A. Krohn and W.J. Orsman, F.I.C. To these
gentlemen my cordial thanks are due. Among the authorities which have
been consulted in the general preparation of the work may be mentioned the
Journals of the Chemical Society, the Society of Chemical Industry, the
United States Naval Institute, and the Royal Artillery Institution. I have also
referred to several volumes of the periodical publication Arms and
Explosives; to various papers by Sir Frederick Abel, Bart., F.R.S., and
General Wardell, R.A., on Gun-Cotton; to "Modern Artillery," by Capt.
Lloyd, R.N., and A.G. Hadcock, R.A.; to the late Colonel Cundill's
"Dictionary of Explosives"; as well as to the works of Messrs Eissler,
Berthelot, and others.
Stowmarket Works of the New Explosives Company Limited, and the Hayle
Works of the National Explosive Company Limited
~Second Edition, Revised and Enlarged~
PREFACE.
In compiling the following treatise, my aim has been to give a brief but
thoroughly practical account of the properties, manufacture, and methods of
analysis of the various nitro-explosives now so largely used for mining and
blasting purposes and as propulsive agents; and it is believed that the
account given of the manufacture of nitro-glycerine and of the gelatine
dynamites will be found more complete than in any similar work yet
published in this country.
For many of the facts and figures contained in the chapter on Smokeless
Powders I am indebted to (amongst others) the late Mr J.D. Dougall and
Messrs A.C. Ponsonby and H.M. Chapman, F.C.S.; and for details with
regard to Roburite to Messrs H.A. Krohn and W.J. Orsman, F.I.C. To these
gentlemen my cordial thanks are due. Among the authorities which have
been consulted in the general preparation of the work may be mentioned the
Journals of the Chemical Society, the Society of Chemical Industry, the
United States Naval Institute, and the Royal Artillery Institution. I have also
referred to several volumes of the periodical publication Arms and
Explosives; to various papers by Sir Frederick Abel, Bart., F.R.S., and
General Wardell, R.A., on Gun-Cotton; to "Modern Artillery," by Capt.
Lloyd, R.N., and A.G. Hadcock, R.A.; to the late Colonel Cundill's
"Dictionary of Explosives"; as well as to the works of Messrs Eissler,
Berthelot, and others.
Page 6
The illustrations have been prepared chiefly from my own drawings. A
few, however, have been taken (by permission) from the pages of Arms and
Explosives, or from other sources which are acknowledged in the text.
P.G.S.
THE LABORATORY,
20 CULLUM STREET, E.C.
May 1896.
PREFACE TO THE SECOND EDITION.
In the preparation of the Second Edition of this work, I have chiefly made
use of the current technical journals, especially of the Journal of the Society
of Chemical Industry. The source of my information has in every case been
acknowledged.
I am also indebted to several manufacturers of explosives for information
respecting their special products—among others the New Explosives
Company
Ltd.; Messrs Curtis's and Harvey Ltd.; The Schultze Gunpowder Company
Ltd.; and Mr W.D. Borland, F.I.C., of the E.C. Powder Company Ltd.
To my friend Mr A. Stanley Fox, F.C.S., of Faversham, my best thanks
are also due for his help in many departments, and his kindness in pointing
out several references.
The chapter on Smokeless Powders has been considerably enlarged and
(as far as possible) brought up to date; but it has not always been possible to
few, however, have been taken (by permission) from the pages of Arms and
Explosives, or from other sources which are acknowledged in the text.
P.G.S.
THE LABORATORY,
20 CULLUM STREET, E.C.
May 1896.
PREFACE TO THE SECOND EDITION.
In the preparation of the Second Edition of this work, I have chiefly made
use of the current technical journals, especially of the Journal of the Society
of Chemical Industry. The source of my information has in every case been
acknowledged.
I am also indebted to several manufacturers of explosives for information
respecting their special products—among others the New Explosives
Company
Ltd.; Messrs Curtis's and Harvey Ltd.; The Schultze Gunpowder Company
Ltd.; and Mr W.D. Borland, F.I.C., of the E.C. Powder Company Ltd.
To my friend Mr A. Stanley Fox, F.C.S., of Faversham, my best thanks
are also due for his help in many departments, and his kindness in pointing
out several references.
The chapter on Smokeless Powders has been considerably enlarged and
(as far as possible) brought up to date; but it has not always been possible to
Page 7
give the process of manufacture or even the composition, as these details
have not, in several cases, been made public.
P. GERALD SANFORD.
LONDON, June 1906.
have not, in several cases, been made public.
P. GERALD SANFORD.
LONDON, June 1906.
Page 8
TABLE OF CONTENTS.
CHAPTER I.—INTRODUCTION.
The Nitro-Explosives—Substances that have been Nitrated—The Danger
Area—
Systems of Professors Lodge, Zenger, and Melsens for the Protection of
Buildings from Lightning, &c.
CHAPTER II.—NITRO-GLYCERINE.
Properties of Nitro-Glycerine—Manufacture—Nitration—Separation—
Washing and Filtering—Drying, Storing, &c.—The Waste Acids—Their
Treatment— Nitric Acid Plants
CHAPTER III.—NITRO-CELLULOSE, &C.
Cellulose Properties—Discovery of Gun-Cotton—Properties of Gun-
Cotton—
Varieties of Soluble and Insoluble Gun-Cottons—Manufacture of Gun-
Cotton—
Dipping and SteepingWhirling Out the Acid—Washing, Boiling, Pulping,
Compressing—The Waltham Abbey Process—Le Bouchet Process—
Granulation of
Gun-Cotton—Collodion-Cotton—Manufacture—Acid Mixture Used—
Cotton Used,
CHAPTER I.—INTRODUCTION.
The Nitro-Explosives—Substances that have been Nitrated—The Danger
Area—
Systems of Professors Lodge, Zenger, and Melsens for the Protection of
Buildings from Lightning, &c.
CHAPTER II.—NITRO-GLYCERINE.
Properties of Nitro-Glycerine—Manufacture—Nitration—Separation—
Washing and Filtering—Drying, Storing, &c.—The Waste Acids—Their
Treatment— Nitric Acid Plants
CHAPTER III.—NITRO-CELLULOSE, &C.
Cellulose Properties—Discovery of Gun-Cotton—Properties of Gun-
Cotton—
Varieties of Soluble and Insoluble Gun-Cottons—Manufacture of Gun-
Cotton—
Dipping and SteepingWhirling Out the Acid—Washing, Boiling, Pulping,
Compressing—The Waltham Abbey Process—Le Bouchet Process—
Granulation of
Gun-Cotton—Collodion-Cotton—Manufacture—Acid Mixture Used—
Cotton Used,
Page 9
&c.—Nitrated Gun-Cotton—Tonite—Dangers in Manufacture of Gun-
Cotton—
Trench's Fire-Extinguishing Compound—Uses of Collodion-Cotton—
Celluloid—
Manufacture, &c.—Nitro-Starch, Nitro-Jute, and Nitro-Mannite
CHAPTER IV.—DYNAMITE.
Kieselguhr Dynamite—Classification of Dynamites—Properties and
Efficiency of Ordinary Dynamite—Other forms of Dynamite—Gelatine and
Gelatine Dynamites, Suitable Gun-Cotton for, and Treatment of—Other
Materials Used—Composition of Gelignite—Blasting Gelatine—Gelatine
Dynamite—Absorbing Materials—Wood Pulp—Potassium Nitrate, &c.—
Manufacture, &c.—Apparatus Used—The Properties of the Gelatine
Compounds
CHAPTER V.—NITRO-BENZOL, ROBURITE, BELLITE, PICRIC ACID, &c.
Explosives derived from Benzene—Toluene and Nitro-Benzene—Di-
and
Tri-nitro-Benzene—Roburite: Properties and Manufacture—Bellite:
Properties, &c.—Securite—Tonite No. 3.—Nitro-Toluene—
Nitro-Naphthalene—Ammonite—Sprengel's Explosives—Picric Acid—
Picrates—Picric Powders—Melinite—Abel's Mixture—Brugère's Powders
—
The Fulminates—Composition, Formula, Preparation, Danger of, &c.—
Detonators: Sizes, Composition, Manufacture—Fuses, &c.
THE FULMINATES.
Composition, Formula, Preparation, Danger of, &c.—Detonators: Sizes,
Composition, Manufacture—Fuses, &c.
Cotton—
Trench's Fire-Extinguishing Compound—Uses of Collodion-Cotton—
Celluloid—
Manufacture, &c.—Nitro-Starch, Nitro-Jute, and Nitro-Mannite
CHAPTER IV.—DYNAMITE.
Kieselguhr Dynamite—Classification of Dynamites—Properties and
Efficiency of Ordinary Dynamite—Other forms of Dynamite—Gelatine and
Gelatine Dynamites, Suitable Gun-Cotton for, and Treatment of—Other
Materials Used—Composition of Gelignite—Blasting Gelatine—Gelatine
Dynamite—Absorbing Materials—Wood Pulp—Potassium Nitrate, &c.—
Manufacture, &c.—Apparatus Used—The Properties of the Gelatine
Compounds
CHAPTER V.—NITRO-BENZOL, ROBURITE, BELLITE, PICRIC ACID, &c.
Explosives derived from Benzene—Toluene and Nitro-Benzene—Di-
and
Tri-nitro-Benzene—Roburite: Properties and Manufacture—Bellite:
Properties, &c.—Securite—Tonite No. 3.—Nitro-Toluene—
Nitro-Naphthalene—Ammonite—Sprengel's Explosives—Picric Acid—
Picrates—Picric Powders—Melinite—Abel's Mixture—Brugère's Powders
—
The Fulminates—Composition, Formula, Preparation, Danger of, &c.—
Detonators: Sizes, Composition, Manufacture—Fuses, &c.
THE FULMINATES.
Composition, Formula, Preparation, Danger of, &c.—Detonators: Sizes,
Composition, Manufacture—Fuses, &c.
Page 10
CHAPTER VI.—SMOKELESS POWDERS IN GENERAL.
Cordite—Axite—Ballistite—U.S. Naval Powder—Schultze's E.C.
Powder—
Indurite—Vielle Poudre—Walsrode and Cooppal Powders—Amberite—
Troisdorf—B.N. Powder—Wetterin—Normal Powder—Maximite—Picric
Acid
Powders, &c. &c.
CHAPTER VII.—ANALYSIS OF EXPLOSIVES.
Kieselguhr Dynamite—Gelatine Compounds—Tonite—Cordite—
Vaseline—
Acetone—Scheme for Analysis of Explosives—Nitro-Cotton—Solubility
Test—
Non-Nitrated Cotton—Alkalinity—Ash and Inorganic Matter—
Determination
of Nitrogen—Lungé, Champion and Pellet's, Schultze-Tieman, and
Kjeldahl's
Methods—Celluloid—Picric Acid and Picrates—Resinous and Tarry
Matters—
Sulphuric Acid and Hydrochloric Acid and Oxalic Acid—Nitric Acid—
Inorganic Impurities—General Impurities and Adulterations—Potassium
Picrate, &c.—Picrates of the Alkaloids—Analysis of Glycerine—Residue
—
Silver Test—Nitration—Total Acid Equivalent—Neutrality—Free Fatty
Acids—Combined Fatty Acids—Impurities—Oleic Acid—Sodium
Chloride—
Determination of Glycerine—Waste Acids—Sodium Nitrate—Mercury
Fulminate—Cap Composition—Table for Correction of Volumes of Gases,
Cordite—Axite—Ballistite—U.S. Naval Powder—Schultze's E.C.
Powder—
Indurite—Vielle Poudre—Walsrode and Cooppal Powders—Amberite—
Troisdorf—B.N. Powder—Wetterin—Normal Powder—Maximite—Picric
Acid
Powders, &c. &c.
CHAPTER VII.—ANALYSIS OF EXPLOSIVES.
Kieselguhr Dynamite—Gelatine Compounds—Tonite—Cordite—
Vaseline—
Acetone—Scheme for Analysis of Explosives—Nitro-Cotton—Solubility
Test—
Non-Nitrated Cotton—Alkalinity—Ash and Inorganic Matter—
Determination
of Nitrogen—Lungé, Champion and Pellet's, Schultze-Tieman, and
Kjeldahl's
Methods—Celluloid—Picric Acid and Picrates—Resinous and Tarry
Matters—
Sulphuric Acid and Hydrochloric Acid and Oxalic Acid—Nitric Acid—
Inorganic Impurities—General Impurities and Adulterations—Potassium
Picrate, &c.—Picrates of the Alkaloids—Analysis of Glycerine—Residue
—
Silver Test—Nitration—Total Acid Equivalent—Neutrality—Free Fatty
Acids—Combined Fatty Acids—Impurities—Oleic Acid—Sodium
Chloride—
Determination of Glycerine—Waste Acids—Sodium Nitrate—Mercury
Fulminate—Cap Composition—Table for Correction of Volumes of Gases,
Page 11
for
Temperature and Pressure
CHAPTER VIII.—FIRING POINT OF EXPLOSIVES, HEAT TESTS, &C.
Horsley's Apparatus—Table of Firing Points—The Government Heat
Test
Apparatus, &c., for Dynamites, Nitro-Glycerine, Nitro-Cotton, and
Smokeless Powders—Guttmann's Heat Test—Liquefaction and Exudation
Tests—
Page's Regulator for Heat Test Apparatus—Specific Gravities of
Explosives—Will's Test for Nitro-Cellulose—Table of Temperature of
Detonation, Sensitiveness, &c.
CHAPTER IX.—THE DETERMINATION OF THE RELATIVE STRENGTH OF
EXPLOSIVES.
Effectiveness of an Explosive—High and Low Explosives—Theoretical
Efficiency—M.M. Roux and Sarrau's Results—Abel and Noble's—Nobel's
Ballistic Test—The Mortar—Pressure or Crusher Gauge—Calculation
Volume of Gas Evolved, &c.—Lead Cylinders—The Foot-Pounds Machine
—Noble's Pressure Gauge—Lieut. Walke's Results—Calculation of
Pressure Developed by Dynamite and Gun-Cotton—McNab's and Ristori's
Results of Heat Developed by the Explosion of Various Explosives—
Composition of some of the Explosives in Common Use for Blasting, &c.
INDEX
LIST OF ILLUSTRATIONS.
Temperature and Pressure
CHAPTER VIII.—FIRING POINT OF EXPLOSIVES, HEAT TESTS, &C.
Horsley's Apparatus—Table of Firing Points—The Government Heat
Test
Apparatus, &c., for Dynamites, Nitro-Glycerine, Nitro-Cotton, and
Smokeless Powders—Guttmann's Heat Test—Liquefaction and Exudation
Tests—
Page's Regulator for Heat Test Apparatus—Specific Gravities of
Explosives—Will's Test for Nitro-Cellulose—Table of Temperature of
Detonation, Sensitiveness, &c.
CHAPTER IX.—THE DETERMINATION OF THE RELATIVE STRENGTH OF
EXPLOSIVES.
Effectiveness of an Explosive—High and Low Explosives—Theoretical
Efficiency—M.M. Roux and Sarrau's Results—Abel and Noble's—Nobel's
Ballistic Test—The Mortar—Pressure or Crusher Gauge—Calculation
Volume of Gas Evolved, &c.—Lead Cylinders—The Foot-Pounds Machine
—Noble's Pressure Gauge—Lieut. Walke's Results—Calculation of
Pressure Developed by Dynamite and Gun-Cotton—McNab's and Ristori's
Results of Heat Developed by the Explosion of Various Explosives—
Composition of some of the Explosives in Common Use for Blasting, &c.
INDEX
LIST OF ILLUSTRATIONS.
Page 12
FRONTISPIECE—Danger Building showing Protecting Mounds. 1.
Section of Nitro-Glycerine Conduit 2. Melsens System of Lightning
Conductors 3. French System 4_a_ & 4_b_. English Government System 5.
Upper Portion of Nitrator for Nitro-Glycerine 6. Small Nitrator 7. Nathan's
Nitrator 8. Nitro-Glycerine Separator 9. Nitro-Glycerine Filtering Apparatus
10. Cotton-Waste Drier 11. Dipping Tank 12. Cooling Pits 13. Steeping Pot
for Gun-Cotton 14. Hydro-Extractor or Centrifugal Drier 15_a_ & 15_b_.
Gun-Cotton Beater 16_a_. Poacher for Pulping Gun-Cotton 16_b_. Plan of
same 16_c_. Another form of Poacher 17 & 18. Compressed Gun-Cotton
19. Hydraulic Press 20. Thomson's Apparatus—Elevation 21. Elevation
Plan 22. Trench's Safety Cartridge 23. Vessel used in Nitrating Paper 24.
Cage ditto—White & Schupphaus' Apparatus 25. Do. do. do. 26 & 27.
Nitrating Pot for Celluloid 28 & 29. Plunge Tank in Plan and Section 30.
Messrs Werner, Pfleiderer & Perkins' Mixing Machine 31. M. 'Roberts'
Mixing Machine for Blasting Gelatine 32. Plan of same 33. Cartridge
Machine for Gelatines 34. Cartridge fitted with Fuse and Detonator 35.
Gun-Cotton Primer 36. Electric Firing Apparatus 37. Metal Drum for
Winding Cordite 38. Ten-Stranding 39. Curve showing relation between
Pressures of Cordite and Black Powder, by Professor Vivian Lewes 40.
Marshall's Apparatus for Moisture in Cordite 41. Lungé's Nitrometer 42.
Modified do. 43. Horn's Nitrometer 44. Schultze-Tieman Apparatus for
Determination of Nitrogen in Gun-Cotton 45. Decomposition Flask for
Schultze-Tieman Method 46. Abel's Heat Test Apparatus 47. Apparatus for
Separation of Nitro-Glycerine from Dynamite 48. Test Tube arranged for
Heat Test 49. Page's Regulator 50. Do. showing Bye-Pass and Cut-off
Arrangement 51. Will's Apparatus 52 & 53. Curves obtained 54. Dynamite
Mortar 55. Quinan's Pressure Gauge 56. Steel Punch and Lead Cylinder for
Use with Pressure Gauge 57. Micrometer Calipers for Measuring Thickness
of Lead Cylinders 58. Section of Lead Cylinders before and after Explosion
59. Noble's Pressure Gauge 60. Crusher Gauge
Section of Nitro-Glycerine Conduit 2. Melsens System of Lightning
Conductors 3. French System 4_a_ & 4_b_. English Government System 5.
Upper Portion of Nitrator for Nitro-Glycerine 6. Small Nitrator 7. Nathan's
Nitrator 8. Nitro-Glycerine Separator 9. Nitro-Glycerine Filtering Apparatus
10. Cotton-Waste Drier 11. Dipping Tank 12. Cooling Pits 13. Steeping Pot
for Gun-Cotton 14. Hydro-Extractor or Centrifugal Drier 15_a_ & 15_b_.
Gun-Cotton Beater 16_a_. Poacher for Pulping Gun-Cotton 16_b_. Plan of
same 16_c_. Another form of Poacher 17 & 18. Compressed Gun-Cotton
19. Hydraulic Press 20. Thomson's Apparatus—Elevation 21. Elevation
Plan 22. Trench's Safety Cartridge 23. Vessel used in Nitrating Paper 24.
Cage ditto—White & Schupphaus' Apparatus 25. Do. do. do. 26 & 27.
Nitrating Pot for Celluloid 28 & 29. Plunge Tank in Plan and Section 30.
Messrs Werner, Pfleiderer & Perkins' Mixing Machine 31. M. 'Roberts'
Mixing Machine for Blasting Gelatine 32. Plan of same 33. Cartridge
Machine for Gelatines 34. Cartridge fitted with Fuse and Detonator 35.
Gun-Cotton Primer 36. Electric Firing Apparatus 37. Metal Drum for
Winding Cordite 38. Ten-Stranding 39. Curve showing relation between
Pressures of Cordite and Black Powder, by Professor Vivian Lewes 40.
Marshall's Apparatus for Moisture in Cordite 41. Lungé's Nitrometer 42.
Modified do. 43. Horn's Nitrometer 44. Schultze-Tieman Apparatus for
Determination of Nitrogen in Gun-Cotton 45. Decomposition Flask for
Schultze-Tieman Method 46. Abel's Heat Test Apparatus 47. Apparatus for
Separation of Nitro-Glycerine from Dynamite 48. Test Tube arranged for
Heat Test 49. Page's Regulator 50. Do. showing Bye-Pass and Cut-off
Arrangement 51. Will's Apparatus 52 & 53. Curves obtained 54. Dynamite
Mortar 55. Quinan's Pressure Gauge 56. Steel Punch and Lead Cylinder for
Use with Pressure Gauge 57. Micrometer Calipers for Measuring Thickness
of Lead Cylinders 58. Section of Lead Cylinders before and after Explosion
59. Noble's Pressure Gauge 60. Crusher Gauge
Page 13
NITRO-EXPLOSIVES.
CHAPTER I.
INTRODUCTORY.
The Nitro-Explosives—Substances that have been Nitrated—The Danger
Area—
Systems of Professors Lodge, Zenger, and Melsens for the Protection of
Buildings from Lightning, &c.
The manufacture of the various nitro-explosives has made great advances
during late years, and the various forms of nitro-compounds are gradually
replacing the older forms of explosives, both for blasting purposes and also
for propulsive agents, under the form of smokeless powders. The nitro-
explosives belong to the so-called High Explosives, and may be defined as
any chemical compound possessed of explosive properties, or capable of
combining with metals to form an explosive compound, which is produced
by the chemical action of nitric acid, either alone or mixed with sulphuric
acid, upon any carbonaceous substance, whether such compound is
mechanically mixed with other substances or not.[A]
[Footnote A: Definition given in Order of Council, No. 1, Explosives Act,
1875.]
CHAPTER I.
INTRODUCTORY.
The Nitro-Explosives—Substances that have been Nitrated—The Danger
Area—
Systems of Professors Lodge, Zenger, and Melsens for the Protection of
Buildings from Lightning, &c.
The manufacture of the various nitro-explosives has made great advances
during late years, and the various forms of nitro-compounds are gradually
replacing the older forms of explosives, both for blasting purposes and also
for propulsive agents, under the form of smokeless powders. The nitro-
explosives belong to the so-called High Explosives, and may be defined as
any chemical compound possessed of explosive properties, or capable of
combining with metals to form an explosive compound, which is produced
by the chemical action of nitric acid, either alone or mixed with sulphuric
acid, upon any carbonaceous substance, whether such compound is
mechanically mixed with other substances or not.[A]
[Footnote A: Definition given in Order of Council, No. 1, Explosives Act,
1875.]
Page 14
The number of compounds and mixtures included under this definition is
very large, and they are of very different chemical composition. Among the
substances that have been nitrated are:—Cellulose, under various forms,
e.g., cotton, lignin, &c.; glycerine, benzene, starch, jute, sugar, phenol,
wood, straw, and even such substances as treacle and horse-dung. Some of
these are not made upon the large scale, others are but little used. Those of
most importance are nitro-glycerine and nitro-cellulose. The former enters
into the composition of all dynamites, and several smokeless powders; and
the second includes gun-cotton, collodion-cotton, nitrated wood, and the
majority of the smokeless powders, which consist generally of nitro-cotton,
nitro-lignin, nitro-jute, &c. &c., together with metallic nitrates, or nitro-
glycerine.
The nitro-explosives consist generally of some organic substance in
which the NO_{2} group, known as nitryl, has been substituted in place of
hydrogen.
Thus in glycerine,
|OH C_{3}H_{5}|OH, |OH
which is a tri-hydric alcohol, and which occurs very widely distributed as
the alcoholic or basic constituent of fats, the hydrogen atoms are replaced
by the NO_{2} group, to form the highly explosive compound, nitro-
glycerine. If one atom only is thus displaced, the mono-nitrate is formed
thus,
|ONO_{2} C_{3}H_{5}|OH; |OH
and if the three atoms are displaced, C_{3}H_{5}(ONO_{2})_{3}, or the
tri- nitrate, is formed, which is commercial nitro-glycerine.
very large, and they are of very different chemical composition. Among the
substances that have been nitrated are:—Cellulose, under various forms,
e.g., cotton, lignin, &c.; glycerine, benzene, starch, jute, sugar, phenol,
wood, straw, and even such substances as treacle and horse-dung. Some of
these are not made upon the large scale, others are but little used. Those of
most importance are nitro-glycerine and nitro-cellulose. The former enters
into the composition of all dynamites, and several smokeless powders; and
the second includes gun-cotton, collodion-cotton, nitrated wood, and the
majority of the smokeless powders, which consist generally of nitro-cotton,
nitro-lignin, nitro-jute, &c. &c., together with metallic nitrates, or nitro-
glycerine.
The nitro-explosives consist generally of some organic substance in
which the NO_{2} group, known as nitryl, has been substituted in place of
hydrogen.
Thus in glycerine,
|OH C_{3}H_{5}|OH, |OH
which is a tri-hydric alcohol, and which occurs very widely distributed as
the alcoholic or basic constituent of fats, the hydrogen atoms are replaced
by the NO_{2} group, to form the highly explosive compound, nitro-
glycerine. If one atom only is thus displaced, the mono-nitrate is formed
thus,
|ONO_{2} C_{3}H_{5}|OH; |OH
and if the three atoms are displaced, C_{3}H_{5}(ONO_{2})_{3}, or the
tri- nitrate, is formed, which is commercial nitro-glycerine.
Page 15
Another class, the nitro-celluloses, are formed from cellulose,
C_{6}H_{10}O_{5}, which forms the groundwork of all vegetable tissues.
Cellulose has some of the properties of the alcohols, and forms ethereal
salts when treated with nitric and sulphuric acids. The hexa-nitrate, or gun-
cotton, has the formula, C_{12}H_{14}O_{4}(ONO_{2})_{6}; and
collodion-cotton, pyroxylin, &c., form the lower nitrates, i.e., the tetra- and
penta-nitrates. These last are soluble in various solvents, such as ether-
alcohol and nitro-glycerine, in which the hexa-nitrate is insoluble. They all
dissolve, however, in acetone and acetic ether.
The solution of the soluble varieties in ether-alcohol is known as
collodion, which finds many applications in the arts. The hydrocarbon
benzene, C_{6}H_{6}, prepared from the light oil obtained from coal-tar,
when nitrated forms nitro-benzenes, such as mono-nitro-benzene,
C_{6}H_{5}NO_{2}, and di-nitro-benzene, C_{6}H_{4}(NO_{2}){2}, in
which one and two atoms are replaced by the NO{2} group. The latter of
these compounds is used as an explosive, and enters into the composition of
such well-known explosives as roburite, &c. The presence of nitro groups
in a substance increases the difficulty of further nitration, and in any case
not more than three nitro groups can be introduced into an aromatic
compound, or the phenols. All aromatic compounds with the general
formula, C_{6}H_{4}X_{2}, give, however, three series. They are called
ortho, meta, or para compounds, depending upon the position of NO_{2}
groups introduced.
Certain regularities have been observed in the formation of nitro-
compounds. If, for example, a substance contains alkyl or hydroxyl groups,
large quantities of the para compound are obtained, and very little of the
ortho. The substitution takes place, however, almost entirely in the meta
position, if a nitro, carboxyl, or aldehyde group be present. Ordinary
phenol, C_{6}H_{5}.OH, gives para- and ortho-nitro-phenol; toluene gives
C_{6}H_{10}O_{5}, which forms the groundwork of all vegetable tissues.
Cellulose has some of the properties of the alcohols, and forms ethereal
salts when treated with nitric and sulphuric acids. The hexa-nitrate, or gun-
cotton, has the formula, C_{12}H_{14}O_{4}(ONO_{2})_{6}; and
collodion-cotton, pyroxylin, &c., form the lower nitrates, i.e., the tetra- and
penta-nitrates. These last are soluble in various solvents, such as ether-
alcohol and nitro-glycerine, in which the hexa-nitrate is insoluble. They all
dissolve, however, in acetone and acetic ether.
The solution of the soluble varieties in ether-alcohol is known as
collodion, which finds many applications in the arts. The hydrocarbon
benzene, C_{6}H_{6}, prepared from the light oil obtained from coal-tar,
when nitrated forms nitro-benzenes, such as mono-nitro-benzene,
C_{6}H_{5}NO_{2}, and di-nitro-benzene, C_{6}H_{4}(NO_{2}){2}, in
which one and two atoms are replaced by the NO{2} group. The latter of
these compounds is used as an explosive, and enters into the composition of
such well-known explosives as roburite, &c. The presence of nitro groups
in a substance increases the difficulty of further nitration, and in any case
not more than three nitro groups can be introduced into an aromatic
compound, or the phenols. All aromatic compounds with the general
formula, C_{6}H_{4}X_{2}, give, however, three series. They are called
ortho, meta, or para compounds, depending upon the position of NO_{2}
groups introduced.
Certain regularities have been observed in the formation of nitro-
compounds. If, for example, a substance contains alkyl or hydroxyl groups,
large quantities of the para compound are obtained, and very little of the
ortho. The substitution takes place, however, almost entirely in the meta
position, if a nitro, carboxyl, or aldehyde group be present. Ordinary
phenol, C_{6}H_{5}.OH, gives para- and ortho-nitro-phenol; toluene gives
Page 16
para- and ortho-nitro-toluene; but nitro-benzene forms meta-di-nitro-
benzene and benzoic acid, meta-nitro-benzoic acid.[A]
[Footnote A: "Organic Chemistry," Prof. Hjelt. Translated by J.B. Tingle,
Ph.D.]
If the graphic formula of benzene be represented thus (No. 1), then the
positions 1 and 2 represent the ortho, 1 and 3 the meta, and 1 and 4 the para
compounds. When the body phenol, C_{6}H_{5}.OH, is nitrated, a
compound is formed known as tri-nitro-phenol, or picric acid, C_{6}H_{2}
(NO_{2}){3}OH, which is used very extensively as an explosive, both as
picric acid and in the form of picrates. Another nitro body that is used as an
explosive is nitro-naphthalene, C{10}H_{6}(NO_{2}){2}, in roburite,
securite, and other explosives of this class. The hexa-nitro- mannite,
C{6}H_{8}(ONO_{2})_{6}, is formed
[Illustration: No. 1]
[Illustration: META-DINITRO-BENZENE No.2]
by treating a substance known as mannite, C_{6}H_{8}(OH)_{6}, an
alcohol formed by the lactic acid fermentation of sugar and closely related
to the sugars, with nitric and sulphuric acids. It is a solid substance, and
very explosive; it contains 18.58 per cent. of nitrogen.
Nitro-starch has also been used for the manufacture of an explosive.
Muhlhauer has described (Ding. Poly. Jour., 73, 137-143) three nitric ethers
of starch, the tetra-nitro-starch, C_{12}H_{16}O_{6}(ONO_{2})_{4}, the
penta- and hexa-nitro-starch. They are formed by acting upon potato starch
dried at 100° C. with a mixture of nitric and sulphuric acids at a temperature
of 20° to 25° C. Rice starch has also been used in its production. Muhlhauer
proposes to use this body as a smokeless powder, and to nitrate it with the
benzene and benzoic acid, meta-nitro-benzoic acid.[A]
[Footnote A: "Organic Chemistry," Prof. Hjelt. Translated by J.B. Tingle,
Ph.D.]
If the graphic formula of benzene be represented thus (No. 1), then the
positions 1 and 2 represent the ortho, 1 and 3 the meta, and 1 and 4 the para
compounds. When the body phenol, C_{6}H_{5}.OH, is nitrated, a
compound is formed known as tri-nitro-phenol, or picric acid, C_{6}H_{2}
(NO_{2}){3}OH, which is used very extensively as an explosive, both as
picric acid and in the form of picrates. Another nitro body that is used as an
explosive is nitro-naphthalene, C{10}H_{6}(NO_{2}){2}, in roburite,
securite, and other explosives of this class. The hexa-nitro- mannite,
C{6}H_{8}(ONO_{2})_{6}, is formed
[Illustration: No. 1]
[Illustration: META-DINITRO-BENZENE No.2]
by treating a substance known as mannite, C_{6}H_{8}(OH)_{6}, an
alcohol formed by the lactic acid fermentation of sugar and closely related
to the sugars, with nitric and sulphuric acids. It is a solid substance, and
very explosive; it contains 18.58 per cent. of nitrogen.
Nitro-starch has also been used for the manufacture of an explosive.
Muhlhauer has described (Ding. Poly. Jour., 73, 137-143) three nitric ethers
of starch, the tetra-nitro-starch, C_{12}H_{16}O_{6}(ONO_{2})_{4}, the
penta- and hexa-nitro-starch. They are formed by acting upon potato starch
dried at 100° C. with a mixture of nitric and sulphuric acids at a temperature
of 20° to 25° C. Rice starch has also been used in its production. Muhlhauer
proposes to use this body as a smokeless powder, and to nitrate it with the
Page 17
spent mixed acids from the manufacture of nitro- glycerine. This substance
contains from 10.96 to 11.09 per cent. of nitrogen. It is a white substance,
very stable and soluble even in cold nitro-glycerine.
The explosive bodies formed by the nitration of jute have been studied by
Messrs Cross and Bevan. and also by Mühlhäuer. The former chemists give
jute the formula C_{12}H_{18}O_{9}, and believe that its conversion into
a nitro-compound takes place according to the equation—
C_{12}H_{18}O_{9} + 3HNO_{3} = 3H_{2}O + C_{12}H_{15}O_(6}(NO_{3})_{3}.
This is equivalent to a gain in weight of 44 per cent. for the tri- nitrate,
and 58 per cent. for the tetra-nitrate. The formation of the tetra-nitrate
appears to be the limit of nitration of jute fibre. Messrs Cross and Bevan
say, "In other words, if we represent the ligno-cellulose molecule by a
C_{12} formula, it will contain four hydroxyl (OH) groups, or two less than
cellulose similarly represented." It contains 11.5 per cent. of nitrogen. The
jute nitrates resemble those of cellulose, and are in all essential points
nitrates of ligno-cellulose.
Nitro-jute is used in the composition of the well-known Cooppal
Smokeless Powders. Cross and Bevan are of opinion that there is no very
obvious advantage in the use of lignified textile fibres as raw materials for
explosive nitrates, seeing that a number of raw materials containing
cellulose (chiefly as cotton) can be obtained at from £10 to £25 a ton, and
yield also 150 to 170 per cent. of explosive material when nitrated (whereas
jute only gives 154.4 per cent.), and are in many ways superior to the
products obtained from jute. Nitro-lignin, or nitrated wood, is, however,
largely used in the composition of a good many of the smokeless powders,
such as Schultze's, the Smokeless Powder Co.'s products, and others.
contains from 10.96 to 11.09 per cent. of nitrogen. It is a white substance,
very stable and soluble even in cold nitro-glycerine.
The explosive bodies formed by the nitration of jute have been studied by
Messrs Cross and Bevan. and also by Mühlhäuer. The former chemists give
jute the formula C_{12}H_{18}O_{9}, and believe that its conversion into
a nitro-compound takes place according to the equation—
C_{12}H_{18}O_{9} + 3HNO_{3} = 3H_{2}O + C_{12}H_{15}O_(6}(NO_{3})_{3}.
This is equivalent to a gain in weight of 44 per cent. for the tri- nitrate,
and 58 per cent. for the tetra-nitrate. The formation of the tetra-nitrate
appears to be the limit of nitration of jute fibre. Messrs Cross and Bevan
say, "In other words, if we represent the ligno-cellulose molecule by a
C_{12} formula, it will contain four hydroxyl (OH) groups, or two less than
cellulose similarly represented." It contains 11.5 per cent. of nitrogen. The
jute nitrates resemble those of cellulose, and are in all essential points
nitrates of ligno-cellulose.
Nitro-jute is used in the composition of the well-known Cooppal
Smokeless Powders. Cross and Bevan are of opinion that there is no very
obvious advantage in the use of lignified textile fibres as raw materials for
explosive nitrates, seeing that a number of raw materials containing
cellulose (chiefly as cotton) can be obtained at from £10 to £25 a ton, and
yield also 150 to 170 per cent. of explosive material when nitrated (whereas
jute only gives 154.4 per cent.), and are in many ways superior to the
products obtained from jute. Nitro-lignin, or nitrated wood, is, however,
largely used in the composition of a good many of the smokeless powders,
such as Schultze's, the Smokeless Powder Co.'s products, and others.
Page 18
~The Danger Area.~—That portion of the works that is devoted to the
actual manufacture or mixing of explosive material is generally designated
by the term "danger area," and the buildings erected upon it are spoken of
as "danger buildings." The best material of which to construct these
buildings is of wood, as in the event of an explosion they will offer less
resistance, and will cause much less danger than brick or stone buildings.
When an explosion of nitro-glycerine or dynamite occurs in one of these
buildings, the sides are generally blown out, and the roof is raised some
considerable height, and finally descends upon the blown-out sides. If, on
the other hand, the same explosion had occurred in a strong brick or stone
building, the walls of which would offer a much larger resistance, large
pieces of brickwork would probably have been thrown for a considerable
distance, and have caused serious damage to surrounding buildings.
It is also a very good plan to surround all danger buildings with mounds
of sand or earth, which should be covered with turf, and of such a height as
to be above the roof of the buildings that they are intended to protect (see
frontispiece).[A] These mounds are of great value in confining the force of
the explosion, and the sides of the buildings being thrown against them are
prevented from travelling any distance. In gunpowder works it is not
unusual to surround the danger buildings with trees or dense underwood
instead of mounds. This would be of no use in checking the force of
explosion of the high explosives, but has been found a very useful
precaution in the case of gunpowder.
[Footnote A: At the Baelen Factory, Belgium, the danger buildings are
erected on a novel plan. They are circular in ground plan and lighted
entirely from the roof by means of a patent glass having wire-netting in it,
and which it is claimed will not let a splinter fall, even if badly cracked. The
mounds are then erected right up against the walls of the building,
exceeding them in height by several metres. For this method of construction
actual manufacture or mixing of explosive material is generally designated
by the term "danger area," and the buildings erected upon it are spoken of
as "danger buildings." The best material of which to construct these
buildings is of wood, as in the event of an explosion they will offer less
resistance, and will cause much less danger than brick or stone buildings.
When an explosion of nitro-glycerine or dynamite occurs in one of these
buildings, the sides are generally blown out, and the roof is raised some
considerable height, and finally descends upon the blown-out sides. If, on
the other hand, the same explosion had occurred in a strong brick or stone
building, the walls of which would offer a much larger resistance, large
pieces of brickwork would probably have been thrown for a considerable
distance, and have caused serious damage to surrounding buildings.
It is also a very good plan to surround all danger buildings with mounds
of sand or earth, which should be covered with turf, and of such a height as
to be above the roof of the buildings that they are intended to protect (see
frontispiece).[A] These mounds are of great value in confining the force of
the explosion, and the sides of the buildings being thrown against them are
prevented from travelling any distance. In gunpowder works it is not
unusual to surround the danger buildings with trees or dense underwood
instead of mounds. This would be of no use in checking the force of
explosion of the high explosives, but has been found a very useful
precaution in the case of gunpowder.
[Footnote A: At the Baelen Factory, Belgium, the danger buildings are
erected on a novel plan. They are circular in ground plan and lighted
entirely from the roof by means of a patent glass having wire-netting in it,
and which it is claimed will not let a splinter fall, even if badly cracked. The
mounds are then erected right up against the walls of the building,
exceeding them in height by several metres. For this method of construction
Page 19
it is claimed that the force exerted by an explosion will expand itself in a
vertical direction ("Report on Visits to Certain Explosive Factories," H.M.
Inspectors, 1905).]
In Great Britain it is necessary that all danger buildings should be a
specified distance apart; a license also must be obtained. The application for
a license must give a plan (drawn to scale) of the proposed factory or
magazine, and the site, its boundaries, and surroundings, and distance the
building will be from any other buildings or works, &c., also the character,
and construction of all the mounds, and nature of the processes to be carried
on in the factory or building.[A]
[Footnote A: Explosives Act, 38 Vict. ch. 17.]
[Illustration: FIG. 1.—SECTION OF NITRO-GLYCERINE CONDUIT.
a, lid; b, lead lining; c, cinders.]
The selection of a site for the danger area requires some attention. The
purpose for which it is required, that is, the kind of explosive that it is
intended to manufacture, must be taken into consideration. A perfectly level
piece of ground might probably be quite suitable for the purpose of erecting
a factory for the manufacture of gun-cotton or gunpowder, and such
materials, but would be more or less unsuitable for the manufacture of
nitro-glycerine, where a number of buildings are required to be upon
different levels, in order to allow of the flow of the liquid nitro- glycerine
from one building to another through a system of conduits. These conduits
(Fig. 1), which are generally made of wood and lined with lead, the space
between the woodwork and the lead lining, which is generally some 4 or 5
inches, being filled with cinders, connect the various buildings, and should
slope gently from one to the other. It is also desirable that, as far as
possible, they should be protected by earth-work banks, in the same way as
vertical direction ("Report on Visits to Certain Explosive Factories," H.M.
Inspectors, 1905).]
In Great Britain it is necessary that all danger buildings should be a
specified distance apart; a license also must be obtained. The application for
a license must give a plan (drawn to scale) of the proposed factory or
magazine, and the site, its boundaries, and surroundings, and distance the
building will be from any other buildings or works, &c., also the character,
and construction of all the mounds, and nature of the processes to be carried
on in the factory or building.[A]
[Footnote A: Explosives Act, 38 Vict. ch. 17.]
[Illustration: FIG. 1.—SECTION OF NITRO-GLYCERINE CONDUIT.
a, lid; b, lead lining; c, cinders.]
The selection of a site for the danger area requires some attention. The
purpose for which it is required, that is, the kind of explosive that it is
intended to manufacture, must be taken into consideration. A perfectly level
piece of ground might probably be quite suitable for the purpose of erecting
a factory for the manufacture of gun-cotton or gunpowder, and such
materials, but would be more or less unsuitable for the manufacture of
nitro-glycerine, where a number of buildings are required to be upon
different levels, in order to allow of the flow of the liquid nitro- glycerine
from one building to another through a system of conduits. These conduits
(Fig. 1), which are generally made of wood and lined with lead, the space
between the woodwork and the lead lining, which is generally some 4 or 5
inches, being filled with cinders, connect the various buildings, and should
slope gently from one to the other. It is also desirable that, as far as
possible, they should be protected by earth-work banks, in the same way as
Page 20
the danger buildings themselves. They should also be provided with covers,
which should be whitewashed in hot weather.
A great deal of attention should be given to these conduits, and they
should be very frequently inspected. Whenever it is found that a portion of
the lead lining requires repairing, before cutting away the lead it should be
very carefully washed, for several feet on either side of the portion that it is
intended to remove, with a solution of caustic soda or potash dissolved in
methylated spirit and water, and afterwards with water alone. This
decomposes the nitro-glycerine forming glycerine and potassium nitrate. It
will be found that the mixed acids attack the lead rather quickly, forming
sulphate and nitrate of lead, but chiefly the former. It is on this account that
it has been proposed to use pipes made of guttapercha, but the great
drawback to their use is that in the case of anything occurring inside the
pipes, such as the freezing of the nitro- glycerine in winter, it is more
difficult to find it out, and the condition of the inside cannot be seen,
whereas in the case of wooden conduits it is an easy matter to lift the lids
along the whole length of the conduit.
The buildings which require to be connected by conduits are of course
those concerned with the manufacture of nitro-glycerine. These buildings
are—(1) The nitrating house; (2) the separating house; (3) the filter house;
(4) the secondary separator; (5) the deposit of washings; (6) the settling or
precipitation house; and each of these buildings must be on a level lower
than the preceding one, in order that the nitro-glycerine or acids may flow
easily from one building to the next. These buildings are, as far as possible,
best placed together, and away from the other danger buildings, such as the
cartridge huts and dynamite mixing houses, but this is not essential.
All danger buildings should be protected by a lightning conductor, or
covered with barbed wire, as suggested by Professor Sir Oliver J. Lodge,
which should be whitewashed in hot weather.
A great deal of attention should be given to these conduits, and they
should be very frequently inspected. Whenever it is found that a portion of
the lead lining requires repairing, before cutting away the lead it should be
very carefully washed, for several feet on either side of the portion that it is
intended to remove, with a solution of caustic soda or potash dissolved in
methylated spirit and water, and afterwards with water alone. This
decomposes the nitro-glycerine forming glycerine and potassium nitrate. It
will be found that the mixed acids attack the lead rather quickly, forming
sulphate and nitrate of lead, but chiefly the former. It is on this account that
it has been proposed to use pipes made of guttapercha, but the great
drawback to their use is that in the case of anything occurring inside the
pipes, such as the freezing of the nitro- glycerine in winter, it is more
difficult to find it out, and the condition of the inside cannot be seen,
whereas in the case of wooden conduits it is an easy matter to lift the lids
along the whole length of the conduit.
The buildings which require to be connected by conduits are of course
those concerned with the manufacture of nitro-glycerine. These buildings
are—(1) The nitrating house; (2) the separating house; (3) the filter house;
(4) the secondary separator; (5) the deposit of washings; (6) the settling or
precipitation house; and each of these buildings must be on a level lower
than the preceding one, in order that the nitro-glycerine or acids may flow
easily from one building to the next. These buildings are, as far as possible,
best placed together, and away from the other danger buildings, such as the
cartridge huts and dynamite mixing houses, but this is not essential.
All danger buildings should be protected by a lightning conductor, or
covered with barbed wire, as suggested by Professor Sir Oliver J. Lodge,
Page 21
F.R.S., Professors Zenger, of Prague, and Melsens, of Brussels, and
everything possible should be done to keep them as cool as possible in the
summer. With this object they should be made double, and the intervening
space filled with cinders. The roof also should be kept whitewashed, and the
windows painted over thinly with white paint. A thermometer should be
suspended in every house. It is very essential that the floors of all these
buildings should be washed every day before the work-people leave. In case
any nitro-glycerine is spilt upon the floors, after sponging it up as far as
possible, the floor should be washed with an alcoholic solution of soda or
potash to decompose the nitro-glycerine, which it does according to the
equation[A]—
C_{3}H_{5}(NO_{3}){3} + 3KOH = C{3}H_{8}O_{3} + 3KNO_{3}.
[Footnote A: See also Berthelot, Comptes Rendus, 1900, 131[12], 519-
521.]
Every one employed in the buildings should wear list or sewn leather
shoes, which of course must be worn in the buildings only. The various
houses should be connected by paths laid with cinders, or boarded with
planks, and any loose sand about the site of the works should be covered
over with turf or cinders, to prevent its blowing about and getting into the
buildings. It is also of importance that stand pipes should be placed about
the works with a good pressure of water, the necessary hose being kept in
certain known places where they can be at once got at in the case of fire,
such as the danger area laboratory, the foreman's office, &c. It is also
desirable that the above precautions against fire should be tested once a
week. With regard to the heating of the various buildings in the winter,
steam pipes only should be used, and should be brought from a boiler-house
outside the danger area, and should be covered with kieselguhr or fossil
meal and tarred canvas. These pipes may be supported upon poles. A stove
everything possible should be done to keep them as cool as possible in the
summer. With this object they should be made double, and the intervening
space filled with cinders. The roof also should be kept whitewashed, and the
windows painted over thinly with white paint. A thermometer should be
suspended in every house. It is very essential that the floors of all these
buildings should be washed every day before the work-people leave. In case
any nitro-glycerine is spilt upon the floors, after sponging it up as far as
possible, the floor should be washed with an alcoholic solution of soda or
potash to decompose the nitro-glycerine, which it does according to the
equation[A]—
C_{3}H_{5}(NO_{3}){3} + 3KOH = C{3}H_{8}O_{3} + 3KNO_{3}.
[Footnote A: See also Berthelot, Comptes Rendus, 1900, 131[12], 519-
521.]
Every one employed in the buildings should wear list or sewn leather
shoes, which of course must be worn in the buildings only. The various
houses should be connected by paths laid with cinders, or boarded with
planks, and any loose sand about the site of the works should be covered
over with turf or cinders, to prevent its blowing about and getting into the
buildings. It is also of importance that stand pipes should be placed about
the works with a good pressure of water, the necessary hose being kept in
certain known places where they can be at once got at in the case of fire,
such as the danger area laboratory, the foreman's office, &c. It is also
desirable that the above precautions against fire should be tested once a
week. With regard to the heating of the various buildings in the winter,
steam pipes only should be used, and should be brought from a boiler-house
outside the danger area, and should be covered with kieselguhr or fossil
meal and tarred canvas. These pipes may be supported upon poles. A stove
Page 22
of some kind should be placed in the corner of each building, but it must be
entirely covered in with woodwork, and as small a length of steam pipes
should be within the building as possible.
In the case of a factory where nitro-glycerine and dynamite are
manufactured, it is necessary that the work-people should wear different
clothes upon the danger area than usual, as they are apt to become
impregnated with nitro-glycerine, and thus not very desirable or safe to
wear outside the works. It is also necessary that these clothes should not
contain any pockets, as this lessens the chance of matches or steel
implements being taken upon the danger area. Changing houses, one for the
men, and another for the girls, should also be provided. The tools used upon
the danger area should, whenever the building is in use, or contains
explosives, be made of phosphor bronze or brass, and brass nails or wooden
pegs should be used in the construction of all the buildings.
[Illustration: FIG. 2.—MELSENS SYSTEM OF LIGHTNING
CONDUCTORS.]
~Lightning Conductors.~—The Explosive Substances Act, 38 Vict. ch.
17, clause 10, says, "Every factory magazine and expense magazine in a
factory, and every danger building in a magazine, shall have attached
thereto a sufficient lightning conductor, unless by reason of the construction
by excavation or the position of such magazine or building, or otherwise,
the Secretary of State considers a conductor unnecessary, and every danger
building in a factory shall, if so required by the Secretary of State, have
attached thereto a sufficient lightning conductor."
The exact form of lightning conductor most suitable for explosive works
and buildings has not yet been definitely settled. Lightning-rod engineers
favour what is known as the Melsens system, due to Professor Melsens, of
Brussels, and Professor Zenger, of Prague, but first suggested by the late
entirely covered in with woodwork, and as small a length of steam pipes
should be within the building as possible.
In the case of a factory where nitro-glycerine and dynamite are
manufactured, it is necessary that the work-people should wear different
clothes upon the danger area than usual, as they are apt to become
impregnated with nitro-glycerine, and thus not very desirable or safe to
wear outside the works. It is also necessary that these clothes should not
contain any pockets, as this lessens the chance of matches or steel
implements being taken upon the danger area. Changing houses, one for the
men, and another for the girls, should also be provided. The tools used upon
the danger area should, whenever the building is in use, or contains
explosives, be made of phosphor bronze or brass, and brass nails or wooden
pegs should be used in the construction of all the buildings.
[Illustration: FIG. 2.—MELSENS SYSTEM OF LIGHTNING
CONDUCTORS.]
~Lightning Conductors.~—The Explosive Substances Act, 38 Vict. ch.
17, clause 10, says, "Every factory magazine and expense magazine in a
factory, and every danger building in a magazine, shall have attached
thereto a sufficient lightning conductor, unless by reason of the construction
by excavation or the position of such magazine or building, or otherwise,
the Secretary of State considers a conductor unnecessary, and every danger
building in a factory shall, if so required by the Secretary of State, have
attached thereto a sufficient lightning conductor."
The exact form of lightning conductor most suitable for explosive works
and buildings has not yet been definitely settled. Lightning-rod engineers
favour what is known as the Melsens system, due to Professor Melsens, of
Brussels, and Professor Zenger, of Prague, but first suggested by the late
Page 23
Professor Clerk-Maxwell. In a paper read before the British Association,
Clerk-Maxwell proposed to protect powder-magazines from the effects of
lightning by completely surrounding or encasing them with sheet metal, or
a cage of metallic conductors. There were, however, several objections to
his system as he left it.
Professor Melsens[A] has, while using the idea, made several important
alterations. He has multiplied the terminals, the conductors, and the earth-
connections. His terminals are very numerous, and assume the form of an
aigrette or brush with five or seven points, the central point being a little
higher than the rest, which form with it an angle of 45°. He employs for the
most part galvanised-iron wire. He places all metallic bodies, if they are of
any considerable size, in communication with the conducting system in
such a manner as to form closed metallic circuits. His system is illustrated
in Fig. 2, taken from Arms and Explosives.
[Footnote A: Belgian Academy of Science.]
This system is a near approximation to J.C. Maxwell's cage. The system
was really designed for the protection of powder-magazines or store
buildings placed in very exposed situations. Zenger's system is identical
with that of Melsens, and has been extensively tried by the Austrian military
authorities, and Colonel Hess has reported upon the absolute safety of the
system.
[Illustration: Fig. 3.—FRENCH SYSTEM OF LIGHTNING
CONDUCTORS.]
The French system of protecting powder-magazines is shown in Fig. 3,
where there are no brush terminals or aigrettes. The French military
authorities also protect magazines by erecting two or more lightning-rods
on poles of sufficient height placed close to, but not touching, the walls of
Clerk-Maxwell proposed to protect powder-magazines from the effects of
lightning by completely surrounding or encasing them with sheet metal, or
a cage of metallic conductors. There were, however, several objections to
his system as he left it.
Professor Melsens[A] has, while using the idea, made several important
alterations. He has multiplied the terminals, the conductors, and the earth-
connections. His terminals are very numerous, and assume the form of an
aigrette or brush with five or seven points, the central point being a little
higher than the rest, which form with it an angle of 45°. He employs for the
most part galvanised-iron wire. He places all metallic bodies, if they are of
any considerable size, in communication with the conducting system in
such a manner as to form closed metallic circuits. His system is illustrated
in Fig. 2, taken from Arms and Explosives.
[Footnote A: Belgian Academy of Science.]
This system is a near approximation to J.C. Maxwell's cage. The system
was really designed for the protection of powder-magazines or store
buildings placed in very exposed situations. Zenger's system is identical
with that of Melsens, and has been extensively tried by the Austrian military
authorities, and Colonel Hess has reported upon the absolute safety of the
system.
[Illustration: Fig. 3.—FRENCH SYSTEM OF LIGHTNING
CONDUCTORS.]
The French system of protecting powder-magazines is shown in Fig. 3,
where there are no brush terminals or aigrettes. The French military
authorities also protect magazines by erecting two or more lightning-rods
on poles of sufficient height placed close to, but not touching, the walls of
Page 24
the magazine. These conductors are joined below the foundations and
earthed as usual.
In the instructions issued by the Government, it is stated that the
lightning-rods placed upon powder-mills should be of such a height, and so
situated, that no danger is incurred in igniting the powder-dust in the air by
the lightning discharge at the pointed rod. In such a case a fork or aigrette of
five or more points should invariably be used in place of a single point.
[Illustration: FIG. 4_a_.—GOVERNMENT SYSTEM OF LIGHTNING
CONDUCTORS FOR
LARGE BUILDINGS.]
[Illustration: FIG. 4_b_.—GOVERNMENT SYSTEM OF LIGHTNING
CONDUCTORS FOR
SMALL BUILDINGS.]
In Fig. 4 (a and b) is shown the Government method for protecting
buildings in which explosives are made or stored. Multiple points or
aigrettes would be better. Lord Kelvin and Professor Melsens favour points,
and it is generally admitted that lightning does not strike buildings at a
single point, but rather in a sheet; hence, in such cases, or in the event of the
globular form being assumed by the lightning, the aigrette will constitute a
much more effective protection than a single point. As to the spacing of
conductors, they may, even on the most important buildings, be spaced at
intervals of 50 feet. There will then be no point on the building more than
25 feet from the conductor. This "25-feet rule" can be adhered to with
advantage in all overground buildings for explosives.
Underground magazines should, whenever possible, also be protected,
because, although less exposed than overground buildings, they frequently
contain explosives packed in metal cases, and hence would present a line of
earthed as usual.
In the instructions issued by the Government, it is stated that the
lightning-rods placed upon powder-mills should be of such a height, and so
situated, that no danger is incurred in igniting the powder-dust in the air by
the lightning discharge at the pointed rod. In such a case a fork or aigrette of
five or more points should invariably be used in place of a single point.
[Illustration: FIG. 4_a_.—GOVERNMENT SYSTEM OF LIGHTNING
CONDUCTORS FOR
LARGE BUILDINGS.]
[Illustration: FIG. 4_b_.—GOVERNMENT SYSTEM OF LIGHTNING
CONDUCTORS FOR
SMALL BUILDINGS.]
In Fig. 4 (a and b) is shown the Government method for protecting
buildings in which explosives are made or stored. Multiple points or
aigrettes would be better. Lord Kelvin and Professor Melsens favour points,
and it is generally admitted that lightning does not strike buildings at a
single point, but rather in a sheet; hence, in such cases, or in the event of the
globular form being assumed by the lightning, the aigrette will constitute a
much more effective protection than a single point. As to the spacing of
conductors, they may, even on the most important buildings, be spaced at
intervals of 50 feet. There will then be no point on the building more than
25 feet from the conductor. This "25-feet rule" can be adhered to with
advantage in all overground buildings for explosives.
Underground magazines should, whenever possible, also be protected,
because, although less exposed than overground buildings, they frequently
contain explosives packed in metal cases, and hence would present a line of
Page 25
smaller electrical resistance than the surrounding earth would offer to the
lightning. The conductor should be arranged on the same system as for
overground buildings, but be applied to the surface of the ground over the
magazines.
In all situations where several conductors are joined in one system, the
vertical conductors should be connected both at the top and near the ground
line. The angles and the prominent portions of a building being the most
liable to be struck, the conductors should be carried over and along these
projections, and therefore along the ridges of the roof. The conductors
should be connected to any outside metal on the roofs and walls, and
specially to the foot of rain-water pipes.
All the lightning conductors should be periodically tested, to see that they
are in working condition, at least every three months, according to Mr
Richard Anderson. The object of the test is to determine the resistance of
the earth-connection, and to localise any defective joints or parts in the
conductors. The best system of testing the conductors is to balance the
resistance of each of the earths against the remainder of the system, from
which the state of the earths may be inferred with sufficient accuracy for all
practical purposes.
Captain Bucknill, R.E., has designed an instrument to test resistance
which is based on the Post Office pattern resistance coil, and is capable of
testing to approximate accuracy up to 200 ohms, and to measure roughly up
to 2,000 ohms. Mr R. Anderson's apparatus is also very handy, consisting of
a case containing three Leclanché cells, and a galvanometer with a
"tangent" scale and certain standard resistances. Some useful articles on the
protection of buildings from lightning will be found in Arms and
Explosives, July, August, and September 1892, and by Mr Anderson, Brit.
Assoc., 1878-80.
lightning. The conductor should be arranged on the same system as for
overground buildings, but be applied to the surface of the ground over the
magazines.
In all situations where several conductors are joined in one system, the
vertical conductors should be connected both at the top and near the ground
line. The angles and the prominent portions of a building being the most
liable to be struck, the conductors should be carried over and along these
projections, and therefore along the ridges of the roof. The conductors
should be connected to any outside metal on the roofs and walls, and
specially to the foot of rain-water pipes.
All the lightning conductors should be periodically tested, to see that they
are in working condition, at least every three months, according to Mr
Richard Anderson. The object of the test is to determine the resistance of
the earth-connection, and to localise any defective joints or parts in the
conductors. The best system of testing the conductors is to balance the
resistance of each of the earths against the remainder of the system, from
which the state of the earths may be inferred with sufficient accuracy for all
practical purposes.
Captain Bucknill, R.E., has designed an instrument to test resistance
which is based on the Post Office pattern resistance coil, and is capable of
testing to approximate accuracy up to 200 ohms, and to measure roughly up
to 2,000 ohms. Mr R. Anderson's apparatus is also very handy, consisting of
a case containing three Leclanché cells, and a galvanometer with a
"tangent" scale and certain standard resistances. Some useful articles on the
protection of buildings from lightning will be found in Arms and
Explosives, July, August, and September 1892, and by Mr Anderson, Brit.
Assoc., 1878-80.
Page 26
~Nitro-Glycerine.~—One of the most powerful of modern explosive
agents is nitro-glycerine. It is the explosive contained in dynamite, and
forms the greater part of the various forms of blasting gelatines, such as
gelatine dynamite and gelignite, both of which substances consist of a
mixture of gun-cotton dissolved in nitro-glycerine, with the addition of
varying proportions of wood-pulp and saltpetre, the latter substances acting
as absorbing materials for the viscid gelatine. Nitro-glycerine is also largely
used in the manufacture of smokeless powders, such as cordite, ballistite,
and several others.
Nitro-glycerol, or glycerol tri-nitrate, was discovered by Sobrero in the
year 1847. In a letter written to M. Pelouse, he says, "when glycerol is
poured into a mixture of sulphuric acid of a specific gravity of 1.84, and of
nitric acid of a gravity of 1.5, which has been cooled by a freezing mixture,
that an oily liquid is formed." This liquid is nitro-glycerol, or nitro-
glycerine, which for some years found no important use in the arts, until the
year 1863, when Alfred Nobel first started a factory in Stockholm for its
manufacture upon a large scale; but on account of some serious accidents
taking place, its use did not become general.
It was not until Nobel conceived the idea (in 1866) of absorbing the
liquid in some absorbent earth, and thus forming the material that is now
known as dynamite, that the use of nitro-glycerine as an explosive became
general.
Among those who improved the manufacture of nitro-glycerine was
Mowbray, who, by using pure glycerine and nitric acid free from nitrous
acid, made very great advances in the manufacture. Mowbray was probably
the first to use compressed air for the purpose of keeping the liquids well
agitated during the process of nitration, which he conducted in earthenware
agents is nitro-glycerine. It is the explosive contained in dynamite, and
forms the greater part of the various forms of blasting gelatines, such as
gelatine dynamite and gelignite, both of which substances consist of a
mixture of gun-cotton dissolved in nitro-glycerine, with the addition of
varying proportions of wood-pulp and saltpetre, the latter substances acting
as absorbing materials for the viscid gelatine. Nitro-glycerine is also largely
used in the manufacture of smokeless powders, such as cordite, ballistite,
and several others.
Nitro-glycerol, or glycerol tri-nitrate, was discovered by Sobrero in the
year 1847. In a letter written to M. Pelouse, he says, "when glycerol is
poured into a mixture of sulphuric acid of a specific gravity of 1.84, and of
nitric acid of a gravity of 1.5, which has been cooled by a freezing mixture,
that an oily liquid is formed." This liquid is nitro-glycerol, or nitro-
glycerine, which for some years found no important use in the arts, until the
year 1863, when Alfred Nobel first started a factory in Stockholm for its
manufacture upon a large scale; but on account of some serious accidents
taking place, its use did not become general.
It was not until Nobel conceived the idea (in 1866) of absorbing the
liquid in some absorbent earth, and thus forming the material that is now
known as dynamite, that the use of nitro-glycerine as an explosive became
general.
Among those who improved the manufacture of nitro-glycerine was
Mowbray, who, by using pure glycerine and nitric acid free from nitrous
acid, made very great advances in the manufacture. Mowbray was probably
the first to use compressed air for the purpose of keeping the liquids well
agitated during the process of nitration, which he conducted in earthenware
Page 27
pots, each containing a charge of 17 lbs. of the mixed acids and 2 lbs. of
glycerol.
A few years later (1872), MM. Boutnny and Faucher, of Vonges,[A]
proposed to prepare nitro-glycerine by mixing the sulphuric acid with the
glycerine, thus forming a sulpho-glyceric acid, which was afterwards mixed
with a mixture of nitric and sulphuric acids. They claimed for this method
of procedure that the final temperature is much lower. The two mixtures are
mixed in the proportions—Glycerine, 100; nitric acid, 280; and sulphuric
acid, 600. They state that the rise of temperature upon mixing is limited
from 10° to 15° C.; but this method requires a period of twenty-four hours
to complete the nitration, which, considering the danger of keeping the
nitro-glycerine in contact with the mixed acids for so long, probably more
than compensates for the somewhat doubtful advantage of being able to
perform the nitration at such a low temperature. The Boutnny process was
in operation for some time at Pembrey Burrows in Wales, but after a serious
explosion the process was abandoned.
[Footnote A: Comptes Rendus, 75; and Desortiaux, "Traité sur la
Poudre," 684-686.]
Nitro-glycerine is now generally made by adding the glycerine to a
mixture of sulphuric and nitric acids. The sulphuric acid, however, takes no
part in the reaction, but is absolutely necessary to combine with the water
that is formed by the decomposition, and thus to keep up the strength of the
nitric acid, otherwise lower nitrates of glycerine would be formed that are
soluble in water, and which would be lost in the subsequent process of
washing to which the nitro-compound is subjected, in order to remove the
excess of acids, the retention of which in the nitro-glycerol is very
dangerous. Nitro-glycerol, which was formerly considered to be a nitro-
substitution compound of glycerol, was thought to be formed thus—
glycerol.
A few years later (1872), MM. Boutnny and Faucher, of Vonges,[A]
proposed to prepare nitro-glycerine by mixing the sulphuric acid with the
glycerine, thus forming a sulpho-glyceric acid, which was afterwards mixed
with a mixture of nitric and sulphuric acids. They claimed for this method
of procedure that the final temperature is much lower. The two mixtures are
mixed in the proportions—Glycerine, 100; nitric acid, 280; and sulphuric
acid, 600. They state that the rise of temperature upon mixing is limited
from 10° to 15° C.; but this method requires a period of twenty-four hours
to complete the nitration, which, considering the danger of keeping the
nitro-glycerine in contact with the mixed acids for so long, probably more
than compensates for the somewhat doubtful advantage of being able to
perform the nitration at such a low temperature. The Boutnny process was
in operation for some time at Pembrey Burrows in Wales, but after a serious
explosion the process was abandoned.
[Footnote A: Comptes Rendus, 75; and Desortiaux, "Traité sur la
Poudre," 684-686.]
Nitro-glycerine is now generally made by adding the glycerine to a
mixture of sulphuric and nitric acids. The sulphuric acid, however, takes no
part in the reaction, but is absolutely necessary to combine with the water
that is formed by the decomposition, and thus to keep up the strength of the
nitric acid, otherwise lower nitrates of glycerine would be formed that are
soluble in water, and which would be lost in the subsequent process of
washing to which the nitro-compound is subjected, in order to remove the
excess of acids, the retention of which in the nitro-glycerol is very
dangerous. Nitro-glycerol, which was formerly considered to be a nitro-
substitution compound of glycerol, was thought to be formed thus—
Page 28
C_{3}H_{8}O_{3} + 3HNO_{3} = C{3}H_{5}(NO_{2}){3}O{3} + 3H_{2}O;
but more recent researches rather point to its being regarded as a nitric
ether of glycerol, or glycerine, and to its being formed thus—
C_{3}H_{8}O_{3} + 3 HNO_{3} = C{3}H_{5}(NO_{3}){3} +
3H{2}O.
92 227
|OH
The formula of glycerine is C_{3}H_{8}O_{8}, or C_{3}H_{5}|OH
|OH
|ONO_{2}
and that of the mono-nitrate of glycerine, C_{3}H_{5}|OH
|OH
|ONO_{2}
and of the tri-nitrate or (nitro-glycerine), C_{3}H_{5}|ONO_{2}
|ONO_{2}
that is, the three hydrogens of the semi-molecules of hydroxyl in the
glycerine have been replaced by the NO_{2} group.
In the manufacture upon the large scale, a mixture of three parts by
weight of nitric acid and five parts of sulphuric acid are used. From the
above equation it will be seen that every 1 lb. of glycerol should give 2.47
lbs. of nitro-glycerol ((227+1)/92 = 2.47), but in practice the yield is only
about 2 lbs. to 2.22, the loss being accounted for by the unavoidable
formation of some of the lower nitrate, which dissolves in water, and is thus
washed away, and partly perhaps to the presence of a little water (or other
non-nitrable matter) in the glycerine, but chiefly to the former, which is due
to the acids having become too weak.
but more recent researches rather point to its being regarded as a nitric
ether of glycerol, or glycerine, and to its being formed thus—
C_{3}H_{8}O_{3} + 3 HNO_{3} = C{3}H_{5}(NO_{3}){3} +
3H{2}O.
92 227
|OH
The formula of glycerine is C_{3}H_{8}O_{8}, or C_{3}H_{5}|OH
|OH
|ONO_{2}
and that of the mono-nitrate of glycerine, C_{3}H_{5}|OH
|OH
|ONO_{2}
and of the tri-nitrate or (nitro-glycerine), C_{3}H_{5}|ONO_{2}
|ONO_{2}
that is, the three hydrogens of the semi-molecules of hydroxyl in the
glycerine have been replaced by the NO_{2} group.
In the manufacture upon the large scale, a mixture of three parts by
weight of nitric acid and five parts of sulphuric acid are used. From the
above equation it will be seen that every 1 lb. of glycerol should give 2.47
lbs. of nitro-glycerol ((227+1)/92 = 2.47), but in practice the yield is only
about 2 lbs. to 2.22, the loss being accounted for by the unavoidable
formation of some of the lower nitrate, which dissolves in water, and is thus
washed away, and partly perhaps to the presence of a little water (or other
non-nitrable matter) in the glycerine, but chiefly to the former, which is due
to the acids having become too weak.
Page 29
CHAPTER II.
MANUFACTURE OF NITRO-GLYCERINE.
Properties of Nitro-Glycerine—Manufacture of Nitro-Glycerine—
Nitration—
The Nathan Nitrator—Separation—Filtering and Washing—The Waste
Acids—
Treatment of the Waste Acid from the Manufacture of Nitro-Glycerine and
Gun-Cotton.
~Properties of Nitro-Glycerine.~—Nitro-glycerol is a heavy oily liquid
of specific gravity 1.6 at 15° C., and when quite pure is colourless. The
commercial product is a pale straw yellow, but varies much according to the
purity of the materials used in its manufacture. It is insoluble in water,
crystallises at 10.5° C., but different commercial samples behave very
differently in this respect, and minute impurities prevent or delay
crystallisation. Solid nitro-glycerol[A] melts at about 12° C., but requires to
be exposed to this temperature for some time before melting. The specific
gravity of the solid form is 1.735 at +10° C.; it contracts one-twelfth of its
volume in solidifying. Beckerheim[B] gives the specific heat as 0.4248
between the temperatures of 9.5° and 9.8° C., and L. de Bruyn gives the
boiling point as above 200°.
MANUFACTURE OF NITRO-GLYCERINE.
Properties of Nitro-Glycerine—Manufacture of Nitro-Glycerine—
Nitration—
The Nathan Nitrator—Separation—Filtering and Washing—The Waste
Acids—
Treatment of the Waste Acid from the Manufacture of Nitro-Glycerine and
Gun-Cotton.
~Properties of Nitro-Glycerine.~—Nitro-glycerol is a heavy oily liquid
of specific gravity 1.6 at 15° C., and when quite pure is colourless. The
commercial product is a pale straw yellow, but varies much according to the
purity of the materials used in its manufacture. It is insoluble in water,
crystallises at 10.5° C., but different commercial samples behave very
differently in this respect, and minute impurities prevent or delay
crystallisation. Solid nitro-glycerol[A] melts at about 12° C., but requires to
be exposed to this temperature for some time before melting. The specific
gravity of the solid form is 1.735 at +10° C.; it contracts one-twelfth of its
volume in solidifying. Beckerheim[B] gives the specific heat as 0.4248
between the temperatures of 9.5° and 9.8° C., and L. de Bruyn gives the
boiling point as above 200°.
Page 30
[Footnote A: Di-nitro-mono chlorhydrin, when added to nitro-glycerine
up to 20 per cent., is said to prevent its freezing.]
[Footnote B: Isb., Chem. Tech., 22, 481-487. 1876.]
Nitro-glycerine has a sweet taste, and causes great depression and
vertigo. It is soluble in ether, chloroform, benzene, glacial acetic acid, and
nitro-benzene, in 1.75 part of methylated spirit, very nearly insoluble in
water, and practically insoluble in carbon bisulphide. Its formula is
C_{3}H_{5}(NO_{3})_{3}, and molecular weight 227. When pure, it may
be kept any length of time without decomposition. Berthelot kept a sample
for ten years, and Mr G. M'Roberts, of the Ardeer Factory, for nine years,
without their showing signs of decomposition; but if it should contain the
smallest trace of free acid, decomposition is certain to be started before
long. This will generally show itself by the formation of little green spots in
the gelatine compounds, or a green ring upon the surface of liquid nitro-
glycerine. Sunlight will often cause it to explode; in fact, a bucket
containing some water that had been used to wash nitro-glycerine, and had
been left standing in the sun, has in our experience been known to explode
with considerable force. Nitro-glycerine when pure is quite stable at
ordinary temperatures, and samples have been kept for years without any
trace of decomposition. It is very susceptible to heat, and even when quite
pure will not stand a temperature of 100° C. for a longer period than a few
hours, without undergoing decomposition. Up to a temperature of 45° C.,
however, properly made and purified nitro- glycerine will remain
unchanged almost indefinitely. The percentage composition of
nitroglycerine is as follows:—
Found. Theory for C_{3}H_{5}(N0_{2})_{3}.
Carbon 15.62 15.86 per cent.
Hydrogen 2.40 2.20 "
up to 20 per cent., is said to prevent its freezing.]
[Footnote B: Isb., Chem. Tech., 22, 481-487. 1876.]
Nitro-glycerine has a sweet taste, and causes great depression and
vertigo. It is soluble in ether, chloroform, benzene, glacial acetic acid, and
nitro-benzene, in 1.75 part of methylated spirit, very nearly insoluble in
water, and practically insoluble in carbon bisulphide. Its formula is
C_{3}H_{5}(NO_{3})_{3}, and molecular weight 227. When pure, it may
be kept any length of time without decomposition. Berthelot kept a sample
for ten years, and Mr G. M'Roberts, of the Ardeer Factory, for nine years,
without their showing signs of decomposition; but if it should contain the
smallest trace of free acid, decomposition is certain to be started before
long. This will generally show itself by the formation of little green spots in
the gelatine compounds, or a green ring upon the surface of liquid nitro-
glycerine. Sunlight will often cause it to explode; in fact, a bucket
containing some water that had been used to wash nitro-glycerine, and had
been left standing in the sun, has in our experience been known to explode
with considerable force. Nitro-glycerine when pure is quite stable at
ordinary temperatures, and samples have been kept for years without any
trace of decomposition. It is very susceptible to heat, and even when quite
pure will not stand a temperature of 100° C. for a longer period than a few
hours, without undergoing decomposition. Up to a temperature of 45° C.,
however, properly made and purified nitro- glycerine will remain
unchanged almost indefinitely. The percentage composition of
nitroglycerine is as follows:—
Found. Theory for C_{3}H_{5}(N0_{2})_{3}.
Carbon 15.62 15.86 per cent.
Hydrogen 2.40 2.20 "
Page 31
Nitrogen 17.90 18.50 "
Oxygen … 63.44 "
The above analysis is by Beckerheim. Sauer and Adou give the nitrogen
as 18.35 to 10.54 per cent. by Dumas' method; but I have never found any
difficulty in obtaining percentages as high as 18.46 by the use of Lunge's
nitrometer. The decomposition products by explosion are shown by the
following equation—
2C_{3}H_{5}(NO_{3}){3} = 6CO{2} + 5H_{2}O + 6N + O;
that is, it contains an excess of 3.52 per cent. of oxygen above that
required for complete combustion; 100 grms. would be converted into—
Carbonic Acid (CO_{2}) 58.15 per cent.
Water 19.83 "
Oxygen 3.52 per cent.
Nitrogen 18.50 "
The volume of gases produced at 0° and 760 mm., calculated from the
above, is 714 litres per kilo, the water being taken as gaseous. Nitro-
glycerine is decomposed differently if it is ignited as dynamite (i.e.,
kieselguhr dynamite), and if the gases are allowed to escape freely under a
pressure nearly equal to that of the atmosphere. Sarrau and Vieille obtained
under these conditions, for 100 volumes of gas—
NO 48.2 per cent.
CO 35.9 "
CO_{2} 12.7 "
H 1.6 per cent.
N 1.3 "
CH_{4} 0.3 "
Oxygen … 63.44 "
The above analysis is by Beckerheim. Sauer and Adou give the nitrogen
as 18.35 to 10.54 per cent. by Dumas' method; but I have never found any
difficulty in obtaining percentages as high as 18.46 by the use of Lunge's
nitrometer. The decomposition products by explosion are shown by the
following equation—
2C_{3}H_{5}(NO_{3}){3} = 6CO{2} + 5H_{2}O + 6N + O;
that is, it contains an excess of 3.52 per cent. of oxygen above that
required for complete combustion; 100 grms. would be converted into—
Carbonic Acid (CO_{2}) 58.15 per cent.
Water 19.83 "
Oxygen 3.52 per cent.
Nitrogen 18.50 "
The volume of gases produced at 0° and 760 mm., calculated from the
above, is 714 litres per kilo, the water being taken as gaseous. Nitro-
glycerine is decomposed differently if it is ignited as dynamite (i.e.,
kieselguhr dynamite), and if the gases are allowed to escape freely under a
pressure nearly equal to that of the atmosphere. Sarrau and Vieille obtained
under these conditions, for 100 volumes of gas—
NO 48.2 per cent.
CO 35.9 "
CO_{2} 12.7 "
H 1.6 per cent.
N 1.3 "
CH_{4} 0.3 "
Page 32
These conditions are similar to those under which a mining charge,
simply ignited by the cap, burns away slowly under a low pressure (i.e., a
miss fire). In a recent communication, P.F. Chalon (Engineering and Mining
Journal, 1892) says, that in practice nitro-glycerine vapour, carbon
monoxide, and nitrous oxide, are also produced as the result of detonation,
but he attributes their formation to the use of a too feeble detonator.
Nitro-glycerine explodes very violently by concussion. It may be burned
in an open vessel, but if heated above 250° C. it explodes. Professor C.E.
Munroe gives the firing point as 2O3°-2O5° C., and L. de Bruyn[A] states
its boiling point as 185°. He used the apparatus devised by Horsley. The
heat of formation of nitro-glycerine, as deduced from the heat of
combustion by M. Longuinine, is 432 calories for 1 grm.; and the heat of
combustion equals 1,576 cals. for 1 grm. In the case of nitro-glycerine the
heat of total combustion and the heat of complete decomposition are
interchangeable terms, since it contains an excess of oxygen. According to
Dr W.H. Perkin, F.R.S.,[B] the magnetic rotation of nitro-gylcerine is 5,407,
and that of tri-methylene nitrate, 4.769 (diff. = .638). Dr Perkin says: "Had
nitro-glycerine contained its nitrogen in any other combination with oxygen
than as -O-NO_{2}, as it might if its constitution had been represented as
C_{3}H_{2}(NO_{2}){3}(OH){3}, the rotation when compared with
propyl nitrate (4.085) would be abnormal."
[Footnote A: Jour. Soc. Chem. Ind., June 1896, p. 471.]
[Footnote B: Jour. Chem. Soc., W.H. Perkin, 1889, p. 726.]
The solubility of nitro-glycerine in various solvents has been investigated
by A.H. Elliot; his results may be summarised as follows:—
___________________________________________________________
____________ | | Solvent. | Cold. | Warm.
simply ignited by the cap, burns away slowly under a low pressure (i.e., a
miss fire). In a recent communication, P.F. Chalon (Engineering and Mining
Journal, 1892) says, that in practice nitro-glycerine vapour, carbon
monoxide, and nitrous oxide, are also produced as the result of detonation,
but he attributes their formation to the use of a too feeble detonator.
Nitro-glycerine explodes very violently by concussion. It may be burned
in an open vessel, but if heated above 250° C. it explodes. Professor C.E.
Munroe gives the firing point as 2O3°-2O5° C., and L. de Bruyn[A] states
its boiling point as 185°. He used the apparatus devised by Horsley. The
heat of formation of nitro-glycerine, as deduced from the heat of
combustion by M. Longuinine, is 432 calories for 1 grm.; and the heat of
combustion equals 1,576 cals. for 1 grm. In the case of nitro-glycerine the
heat of total combustion and the heat of complete decomposition are
interchangeable terms, since it contains an excess of oxygen. According to
Dr W.H. Perkin, F.R.S.,[B] the magnetic rotation of nitro-gylcerine is 5,407,
and that of tri-methylene nitrate, 4.769 (diff. = .638). Dr Perkin says: "Had
nitro-glycerine contained its nitrogen in any other combination with oxygen
than as -O-NO_{2}, as it might if its constitution had been represented as
C_{3}H_{2}(NO_{2}){3}(OH){3}, the rotation when compared with
propyl nitrate (4.085) would be abnormal."
[Footnote A: Jour. Soc. Chem. Ind., June 1896, p. 471.]
[Footnote B: Jour. Chem. Soc., W.H. Perkin, 1889, p. 726.]
The solubility of nitro-glycerine in various solvents has been investigated
by A.H. Elliot; his results may be summarised as follows:—
___________________________________________________________
____________ | | Solvent. | Cold. | Warm.
Page 33
_____________________________|______________________|_________
_________ | | Water | Insoluble | Slightly soluble Alcohol, absolute | Soluble
| Soluble " 93% | " | " " 80% | Slowly soluble | " " 50% | Insoluble | Slightly
soluble Methyl alcohol | Soluble | Soluble Amyl " | " | " Ether, ethylic | " | "
" acetic | " | " Chloroform | " | " Acetone | " | " Sulphuric acid (1.845) | " | "
Nitric acid (1.400) | Slowly soluble | " Hydrochloric acid (1.200) | Insoluble,
decomposed| Slowly soluble Acetic acid, glacial | Soluble | Soluble Carbolic
acid | " | " Astral oil | Insoluble | Insoluble Olive " | Soluble | Soluble
Stearine oil | " | " Mineral jelly | Insoluble | Insoluble Glycerine | " | "
Benzene | Soluble | Soluble Nitro-benzene | " | " Toluene | " | " Carbon bi-
sulphide | Insoluble | Slightly affected Turpentine | " | Soluble Petroleum
naphtha, 71°-76° B.| " | Insoluble Caustic soda (1:10 solution) | Insoluble. |
Insoluble. Borax, 5% solution | " | " Ammonia (.980) | " | " slightly | |
affected. Ammonium sulph-hydrate | Insoluble, sulphur | Decomposed. |
separates | Iron sulphate solution | Slightly affected | Affected. Iron chloride
(1.4 grm. Fe | Slowly affected | Decomposed. to 10 c.c. N_{2}O) | | Tin
chloride | Slightly affected | Affected.
_____________________________|______________________|_________
_________
Many attempts have been made to prepare nitro-glycerine explosives
capable of withstanding comparatively low temperatures without freezing,
but no satisfactory solution of the problem has been found. Among the
substances that have been proposed and used with more or less success, are
nitro- benzene, nitro-toluene, di-nitro-mono-chlorhydrine, solid nitro
derivatives of toluene,[A] are stated to lower the freezing point of nitro-
glycerine to -20°C. without altering its sensitiveness and stability. The
subject has been investigated by S. Nauckhoff,[B] who states that
nitroglycerine can be cooled to temperatures (-40° to -50° C.) much below
its true freezing point, without solidifying, by the addition of various
substances. When cooled by means of a mixture of solid carbon, dioxide,
_________ | | Water | Insoluble | Slightly soluble Alcohol, absolute | Soluble
| Soluble " 93% | " | " " 80% | Slowly soluble | " " 50% | Insoluble | Slightly
soluble Methyl alcohol | Soluble | Soluble Amyl " | " | " Ether, ethylic | " | "
" acetic | " | " Chloroform | " | " Acetone | " | " Sulphuric acid (1.845) | " | "
Nitric acid (1.400) | Slowly soluble | " Hydrochloric acid (1.200) | Insoluble,
decomposed| Slowly soluble Acetic acid, glacial | Soluble | Soluble Carbolic
acid | " | " Astral oil | Insoluble | Insoluble Olive " | Soluble | Soluble
Stearine oil | " | " Mineral jelly | Insoluble | Insoluble Glycerine | " | "
Benzene | Soluble | Soluble Nitro-benzene | " | " Toluene | " | " Carbon bi-
sulphide | Insoluble | Slightly affected Turpentine | " | Soluble Petroleum
naphtha, 71°-76° B.| " | Insoluble Caustic soda (1:10 solution) | Insoluble. |
Insoluble. Borax, 5% solution | " | " Ammonia (.980) | " | " slightly | |
affected. Ammonium sulph-hydrate | Insoluble, sulphur | Decomposed. |
separates | Iron sulphate solution | Slightly affected | Affected. Iron chloride
(1.4 grm. Fe | Slowly affected | Decomposed. to 10 c.c. N_{2}O) | | Tin
chloride | Slightly affected | Affected.
_____________________________|______________________|_________
_________
Many attempts have been made to prepare nitro-glycerine explosives
capable of withstanding comparatively low temperatures without freezing,
but no satisfactory solution of the problem has been found. Among the
substances that have been proposed and used with more or less success, are
nitro- benzene, nitro-toluene, di-nitro-mono-chlorhydrine, solid nitro
derivatives of toluene,[A] are stated to lower the freezing point of nitro-
glycerine to -20°C. without altering its sensitiveness and stability. The
subject has been investigated by S. Nauckhoff,[B] who states that
nitroglycerine can be cooled to temperatures (-40° to -50° C.) much below
its true freezing point, without solidifying, by the addition of various
substances. When cooled by means of a mixture of solid carbon, dioxide,
Page 34
and ether, it sets to a glassy mass, without any perceptible crystallisation.
The mass when warmed to 0°C. first rapidly liquefies and then begins to
crystallise. The true freezing point of pure nitro- glycerine was found to be
12.3°C. The technical product, owing to the presence of di-nitro-glycerine,
freezes at 10.5° C. According to Raoult's law, the lowering of the freezing
point caused by m grms. of a substance with the molecular weight M, when
dissolved in 100 grms. of the solvent, is expressed by the formula: [Delta] =
E(m/M), where E is a constant characteristic for the solvent in question. The
value of E for nitro- glycerine was found to be 70.5 when calculated,
according to Van't Hoff's formula, from the melting point and the latent heat
of fusion of the substance. Determinations of the lowering of the freezing
point of nitro- glycerine by additions of benzene, nitro-benzene, di-nitro-
benzene, tri- nitro-benzene, p.-nitro-toluene, o.-nitro-toluene, di-nitro-
toluene, naphthalene, nitro-naphthalene, di-nitro-naphthalene, ethyl acetate,
ethyl nitrate, and methyl alcohol, gave results agreeing fairly well with
Raoult's formula, except in the case of methyl alcohol, for which the
calculated lowering of the freezing point was greater than that observed,
probably owing to the formation of complex molecules in the solution. The
results show that, in general, the capacity of a substance to lower the
freezing point of nitro-glycerine depends, not upon its freezing point, or its
chemical composition or constitution, but upon its molecular weight.
Nauckhoff states that a suitable substance for dissolving in nitro- glycerine,
in order to lower the freezing point of the latter, must have a relatively low
molecular weight, must not appreciably diminish the explosive power and
stability of the explosive, and must not be easily volatile at relatively high
atmospheric temperatures; it should, if possible, be a solvent of nitro-
cellulose, and in every case must not have a prejudicial influence on the
gelatinisation of the nitro-cellulose.
[Footnote A: Eng. Pat. 25,797, November 1904.]
The mass when warmed to 0°C. first rapidly liquefies and then begins to
crystallise. The true freezing point of pure nitro- glycerine was found to be
12.3°C. The technical product, owing to the presence of di-nitro-glycerine,
freezes at 10.5° C. According to Raoult's law, the lowering of the freezing
point caused by m grms. of a substance with the molecular weight M, when
dissolved in 100 grms. of the solvent, is expressed by the formula: [Delta] =
E(m/M), where E is a constant characteristic for the solvent in question. The
value of E for nitro- glycerine was found to be 70.5 when calculated,
according to Van't Hoff's formula, from the melting point and the latent heat
of fusion of the substance. Determinations of the lowering of the freezing
point of nitro- glycerine by additions of benzene, nitro-benzene, di-nitro-
benzene, tri- nitro-benzene, p.-nitro-toluene, o.-nitro-toluene, di-nitro-
toluene, naphthalene, nitro-naphthalene, di-nitro-naphthalene, ethyl acetate,
ethyl nitrate, and methyl alcohol, gave results agreeing fairly well with
Raoult's formula, except in the case of methyl alcohol, for which the
calculated lowering of the freezing point was greater than that observed,
probably owing to the formation of complex molecules in the solution. The
results show that, in general, the capacity of a substance to lower the
freezing point of nitro-glycerine depends, not upon its freezing point, or its
chemical composition or constitution, but upon its molecular weight.
Nauckhoff states that a suitable substance for dissolving in nitro- glycerine,
in order to lower the freezing point of the latter, must have a relatively low
molecular weight, must not appreciably diminish the explosive power and
stability of the explosive, and must not be easily volatile at relatively high
atmospheric temperatures; it should, if possible, be a solvent of nitro-
cellulose, and in every case must not have a prejudicial influence on the
gelatinisation of the nitro-cellulose.
[Footnote A: Eng. Pat. 25,797, November 1904.]
Page 35
[Footnote B: Z. Angew. Chem., 1905, 18, 11-22, 53-60.]
~Manufacture of Nitro-Glycerine.~—Nitro-glycerine is prepared upon
the manufacturing scale by gradually adding glycerine to a mixture of nitric
and sulphuric acids of great strength. The mixed acids are contained in a
lead vessel, which is kept cool by a stream of water continually passing
through worms in the interior of the nitrating vessel, and the glycerine is
gradually added in the form of a fine stream from above. The manufacture
can be divided into three distinct operations, viz., nitration, separation, and
washing, and it will be well to describe these operations in the above order.
~Nitration.~—The most essential condition of nitrating is the correct
composition and strength of the mixed acids. The best proportions have
been found to be three parts by weight of nitric acid of a specific gravity
1.525 to 1.530, and containing as small a portion of the oxides of nitrogen
as possible, to five parts by weight of sulphuric acid of a specific gravity of
1.840 at 15° C., and about 97 per cent. of mono- hydrate. It is of the very
greatest importance that the nitric acid should be as strong as possible.
Nothing under a gravity of 1.52 should ever be used even to mix with
stronger acid, and the nitration will be proportional to the strength of the
acid used, provided the sulphuric acid is also strong enough. It is also of
great importance that the oxides of nitrogen should be low, and that they
should be kept down to as low as 1 per cent., or even lower. It is also very
desirable that the nitric acid should contain as little chlorine as possible.
The following is the analysis of a sample of nitric acid, which gave very
good results upon the commercial scale:—Specific gravity, 1.525,
N_{2}O_{4}, 1.03 per cent.; nitric acid (HNO_{3}), 95.58 per cent.
The amount of real nitric acid (mono-hydrate) and the amount of nitric
peroxide present in any sample should always be determined before it is
used for nitrating purposes. The specific gravity is not a sufficient guide to
~Manufacture of Nitro-Glycerine.~—Nitro-glycerine is prepared upon
the manufacturing scale by gradually adding glycerine to a mixture of nitric
and sulphuric acids of great strength. The mixed acids are contained in a
lead vessel, which is kept cool by a stream of water continually passing
through worms in the interior of the nitrating vessel, and the glycerine is
gradually added in the form of a fine stream from above. The manufacture
can be divided into three distinct operations, viz., nitration, separation, and
washing, and it will be well to describe these operations in the above order.
~Nitration.~—The most essential condition of nitrating is the correct
composition and strength of the mixed acids. The best proportions have
been found to be three parts by weight of nitric acid of a specific gravity
1.525 to 1.530, and containing as small a portion of the oxides of nitrogen
as possible, to five parts by weight of sulphuric acid of a specific gravity of
1.840 at 15° C., and about 97 per cent. of mono- hydrate. It is of the very
greatest importance that the nitric acid should be as strong as possible.
Nothing under a gravity of 1.52 should ever be used even to mix with
stronger acid, and the nitration will be proportional to the strength of the
acid used, provided the sulphuric acid is also strong enough. It is also of
great importance that the oxides of nitrogen should be low, and that they
should be kept down to as low as 1 per cent., or even lower. It is also very
desirable that the nitric acid should contain as little chlorine as possible.
The following is the analysis of a sample of nitric acid, which gave very
good results upon the commercial scale:—Specific gravity, 1.525,
N_{2}O_{4}, 1.03 per cent.; nitric acid (HNO_{3}), 95.58 per cent.
The amount of real nitric acid (mono-hydrate) and the amount of nitric
peroxide present in any sample should always be determined before it is
used for nitrating purposes. The specific gravity is not a sufficient guide to
Page 36
the strength of the acid, as an acid having a high gravity, due to some 3 or 4
per cent of nitric oxides in solution, will give very poor nitration results. A
tenth normal solution of sodium hydroxide (NaOH), with phenol-phthalein
as indicator, will be found the most convenient method of determining the
total acid present. The following method will be found to be very rapid and
reliable:—Weigh a 100 c.c. flask, containing a few cubic centimetres of
distilled water, and then add from a pipette 1 c.c. of the nitric acid to be
examined, and reweigh (this gives the weight of acid taken). Now make up
to 100 c.c. at 15° C.; shake well, and take out 10 c.c. with a pipette; drain
into a small Erlenmeyer flask, and add a little of the phenol-phthalein
solution, and titrate with the tenth normal soda solution.
The nitric peroxide can be determined with a solution of potassium
permanganate of N/10 strength, thus: Take a small conical flask, containing
about 10 c.c. of water, and add from a burette 10 to 16 c.c. of the
permanganate solution; then add 2 c.c. of the acid to be tested, and shake
gently, and continue to add permanganate solution as long as it is
decolourised, and until a faint pink colour is permanent.
Example. N/10 permanganate 3.16 grms. per litre, 1 c.c. = O.0046 grm.
N_{2}O_{4}, 2 c.c. of sample of acid specific gravity 1.52 = 3.04 grms.
taken for analysis. Took 20 c.c. permanganate solution, O.0046 x 20 =.092
grm. N_{2}O_{4}, and (.092 x 100)/3.04 = 3.02 per cent. N_{2}O_{4}.
The specific gravity should be taken with an hydrometer that gives the
specific gravity directly, or, if preferred, the 2 c.c. of acid may be weighed.
A very good method of rapidly determining the strength of the sulphuric
acid is as follows:—Weigh out in a small weighing bottle, as nearly as
possible, 2.45 grms. This is best done by running in 1.33 c.c. of the acid
(1.33 x 1.84 = 2.447). Wash into a large Erlenmeyer flask, carefully
washing out the bottle, and also the stopper, &c. Add a drop of phenol-
per cent of nitric oxides in solution, will give very poor nitration results. A
tenth normal solution of sodium hydroxide (NaOH), with phenol-phthalein
as indicator, will be found the most convenient method of determining the
total acid present. The following method will be found to be very rapid and
reliable:—Weigh a 100 c.c. flask, containing a few cubic centimetres of
distilled water, and then add from a pipette 1 c.c. of the nitric acid to be
examined, and reweigh (this gives the weight of acid taken). Now make up
to 100 c.c. at 15° C.; shake well, and take out 10 c.c. with a pipette; drain
into a small Erlenmeyer flask, and add a little of the phenol-phthalein
solution, and titrate with the tenth normal soda solution.
The nitric peroxide can be determined with a solution of potassium
permanganate of N/10 strength, thus: Take a small conical flask, containing
about 10 c.c. of water, and add from a burette 10 to 16 c.c. of the
permanganate solution; then add 2 c.c. of the acid to be tested, and shake
gently, and continue to add permanganate solution as long as it is
decolourised, and until a faint pink colour is permanent.
Example. N/10 permanganate 3.16 grms. per litre, 1 c.c. = O.0046 grm.
N_{2}O_{4}, 2 c.c. of sample of acid specific gravity 1.52 = 3.04 grms.
taken for analysis. Took 20 c.c. permanganate solution, O.0046 x 20 =.092
grm. N_{2}O_{4}, and (.092 x 100)/3.04 = 3.02 per cent. N_{2}O_{4}.
The specific gravity should be taken with an hydrometer that gives the
specific gravity directly, or, if preferred, the 2 c.c. of acid may be weighed.
A very good method of rapidly determining the strength of the sulphuric
acid is as follows:—Weigh out in a small weighing bottle, as nearly as
possible, 2.45 grms. This is best done by running in 1.33 c.c. of the acid
(1.33 x 1.84 = 2.447). Wash into a large Erlenmeyer flask, carefully
washing out the bottle, and also the stopper, &c. Add a drop of phenol-
Page 37
phthalein solution and titrate, with a half normal solution of sodium hydrate
(use a 100 c.c. burette). Then if 2.45 grms. exactly have been taken, the
readings on the burette will equal percentages of H_{2}SO_{4} (mono-
hydrate) if not, calculate thus:—2.444 grms. weighed, required 95.4 c.c.
NaOH. Then—
2.444 : 95.4 :: 2.45 : x = 95.64 per cent. H_{2}SO_{4}.
It has been proposed to free nitric acid from the oxides of nitrogen by
blowing compressed air through it, and thus driving the gases in solution
out. The acid was contained in a closed lead tank, from which the escaping
fumes were conducted into the chimney shaft, and on the bottom of which
was a lead pipe, bent in the form of a circle, and pierced with holes, through
which the compressed air was made to pass; but the process was not found
to be of a very satisfactory nature, and it is certainly better not to allow the
formation of these compounds in the manufacture of the acid in the first
instance. Another plan, however, is to heat the acid gently, and thus drive
out the nitrous gases. Both processes involve loss of nitric acid.
Having obtained nitric and sulphuric acids as pure as possible, the next
operation is to mix them. This is best done by weighing the carboys in
which the acids are generally stored before the acids are drawn off into
them from the condensers, and keeping their weights constantly attached to
them by means of a label. It is then a simple matter to weigh off as many
carboys of acid as may be required for any number of mixings, and subtract
the weights of the carboys. The two acids should, after being weighed, be
poured into a tank and mixed, and subsequently allowed to flow into an
acid egg or montjus, to be afterwards forced up to the nitrating house in the
danger area. The montjus or acid egg is a strong cast-iron tank, of either an
egg shape, or a cylinder with a round end. If of the former shape, it would
lie on its side, and upon the surface of the ground, and would have a
(use a 100 c.c. burette). Then if 2.45 grms. exactly have been taken, the
readings on the burette will equal percentages of H_{2}SO_{4} (mono-
hydrate) if not, calculate thus:—2.444 grms. weighed, required 95.4 c.c.
NaOH. Then—
2.444 : 95.4 :: 2.45 : x = 95.64 per cent. H_{2}SO_{4}.
It has been proposed to free nitric acid from the oxides of nitrogen by
blowing compressed air through it, and thus driving the gases in solution
out. The acid was contained in a closed lead tank, from which the escaping
fumes were conducted into the chimney shaft, and on the bottom of which
was a lead pipe, bent in the form of a circle, and pierced with holes, through
which the compressed air was made to pass; but the process was not found
to be of a very satisfactory nature, and it is certainly better not to allow the
formation of these compounds in the manufacture of the acid in the first
instance. Another plan, however, is to heat the acid gently, and thus drive
out the nitrous gases. Both processes involve loss of nitric acid.
Having obtained nitric and sulphuric acids as pure as possible, the next
operation is to mix them. This is best done by weighing the carboys in
which the acids are generally stored before the acids are drawn off into
them from the condensers, and keeping their weights constantly attached to
them by means of a label. It is then a simple matter to weigh off as many
carboys of acid as may be required for any number of mixings, and subtract
the weights of the carboys. The two acids should, after being weighed, be
poured into a tank and mixed, and subsequently allowed to flow into an
acid egg or montjus, to be afterwards forced up to the nitrating house in the
danger area. The montjus or acid egg is a strong cast-iron tank, of either an
egg shape, or a cylinder with a round end. If of the former shape, it would
lie on its side, and upon the surface of the ground, and would have a
Page 38
manhole at one end, upon which a lid would be strongly bolted down; but if
of the latter shape, the lid, of course, is upon the top, and the montjus itself
is let into the ground. In either case, the principle is the same. One pipe,
made of stout lead, goes to the bottom, and another just inside to convey the
compressed air, the acids flowing away as the pressure is put on, just as
blowing down one tube of an ordinary wash- bottle forces the water up the
other tube to the jet. The pressure necessarily will, of course, vary
immensely, and will depend upon the height to which the acid has to be
raised and the distance to be traversed.
The mixed acids having been forced up to the danger area, and to a level
higher than the position of the nitrating house, should, before being used, be
allowed to cool, and leaden tanks of sufficient capacity to hold at least
enough acid for four or five nitrations should be placed in a wooden house
upon a level at least 6 or 7 feet above the nitrating house. In this house also
should be a smaller lead tank, holding, when filled to a certain mark, just
enough of the mixed acids for one nitration. The object of this tank is, that
as soon as the man in charge knows that the last nitration is finished, he
refills this smaller tank (which contains just enough of the mixed acids),
and allows its contents to flow down into the nitrating house and into the
nitrator, ready for the next nitration. The nitration is usually conducted in a
vessel constructed of lead, some 4 feet wide at the bottom, and rather less at
the top, and about 4 feet or so high. The size, of course, depends upon the
volume of the charge it is intended to nitrate at one operation, but it is
always better that the tank should be only two-thirds full. A good charge is
16 cwt. of the mixed acids, in the proportion of three to five; that is, 6 cwt.
of nitric acid, and 10 cwt. of sulphuric acid, and 247 lbs. of glycerine.
Upon reference to the equation showing the formation of nitro-glycerine,
it will be seen that for every 1 lb. of glycerine 2.47 lbs. of nitro- glycerine
should be furnished,[A] but in practice the yield is only a little over 2 lbs.,
of the latter shape, the lid, of course, is upon the top, and the montjus itself
is let into the ground. In either case, the principle is the same. One pipe,
made of stout lead, goes to the bottom, and another just inside to convey the
compressed air, the acids flowing away as the pressure is put on, just as
blowing down one tube of an ordinary wash- bottle forces the water up the
other tube to the jet. The pressure necessarily will, of course, vary
immensely, and will depend upon the height to which the acid has to be
raised and the distance to be traversed.
The mixed acids having been forced up to the danger area, and to a level
higher than the position of the nitrating house, should, before being used, be
allowed to cool, and leaden tanks of sufficient capacity to hold at least
enough acid for four or five nitrations should be placed in a wooden house
upon a level at least 6 or 7 feet above the nitrating house. In this house also
should be a smaller lead tank, holding, when filled to a certain mark, just
enough of the mixed acids for one nitration. The object of this tank is, that
as soon as the man in charge knows that the last nitration is finished, he
refills this smaller tank (which contains just enough of the mixed acids),
and allows its contents to flow down into the nitrating house and into the
nitrator, ready for the next nitration. The nitration is usually conducted in a
vessel constructed of lead, some 4 feet wide at the bottom, and rather less at
the top, and about 4 feet or so high. The size, of course, depends upon the
volume of the charge it is intended to nitrate at one operation, but it is
always better that the tank should be only two-thirds full. A good charge is
16 cwt. of the mixed acids, in the proportion of three to five; that is, 6 cwt.
of nitric acid, and 10 cwt. of sulphuric acid, and 247 lbs. of glycerine.
Upon reference to the equation showing the formation of nitro-glycerine,
it will be seen that for every 1 lb. of glycerine 2.47 lbs. of nitro- glycerine
should be furnished,[A] but in practice the yield is only a little over 2 lbs.,
Page 39
the loss being accounted for by the unavoidable formation of some of the
lower nitrate of glycerine (the mono-nitrate), which afterward dissolves in
the washing waters. The lead tank (Fig. 5) is generally cased in woodwork,
with a platform in front for the man in charge of the nitrating to stand upon,
and whence to work the various taps. The top of the tank is closed in with a
dome of lead, in which is a small glass window, through which the progress
of the nitrating operation can be watched. From the top of this dome is a
tube of lead which is carried up through the roof of the building. It serves as
a chimney to carry off the acid fumes which are given off during the
nitration. The interior of this tank contains at least three concentric spirals
of at least 1-inch lead pipe, through which water can be made to flow
during the whole operation of nitrating. Another lead pipe is carried through
the dome of the tank, as far as the bottom, where it is bent round in the form
of a circle. Through this pipe, which is pierced with small holes, about 1
inch apart, compressed air is forced at a pressure of about 60 lbs. in order to
keep the liquids in a state of constant agitation during the whole period of
nitration. There must also be a rather wide pipe, of say 2 inches internal
diameter, carried through the dome of the tank, which will serve to carry the
mixed acid to be used in the operation into the tank. There is still another
pipe to go through the dome, viz., one to carry the glycerine into the tank.
This need not be a large bore pipe, as the glycerine is generally added to the
mixed acids in a thin stream (an injector is often used).
[Footnote A: Thus if 92 lbs. glycerine give 227 lbs. nitro-glycerine, (277
x 1)/92 = 2.47 lbs.]
[Illustration: FIG. 5.—TOP OF NITRATOR. A, Fume Pipe; B, Water
Pipes for Cooling; C, Acid Mixture Pipe; E, Compressed Air; G, Glycerine
Pipe and Funnel; T, Thermometer; W, Window.]
lower nitrate of glycerine (the mono-nitrate), which afterward dissolves in
the washing waters. The lead tank (Fig. 5) is generally cased in woodwork,
with a platform in front for the man in charge of the nitrating to stand upon,
and whence to work the various taps. The top of the tank is closed in with a
dome of lead, in which is a small glass window, through which the progress
of the nitrating operation can be watched. From the top of this dome is a
tube of lead which is carried up through the roof of the building. It serves as
a chimney to carry off the acid fumes which are given off during the
nitration. The interior of this tank contains at least three concentric spirals
of at least 1-inch lead pipe, through which water can be made to flow
during the whole operation of nitrating. Another lead pipe is carried through
the dome of the tank, as far as the bottom, where it is bent round in the form
of a circle. Through this pipe, which is pierced with small holes, about 1
inch apart, compressed air is forced at a pressure of about 60 lbs. in order to
keep the liquids in a state of constant agitation during the whole period of
nitration. There must also be a rather wide pipe, of say 2 inches internal
diameter, carried through the dome of the tank, which will serve to carry the
mixed acid to be used in the operation into the tank. There is still another
pipe to go through the dome, viz., one to carry the glycerine into the tank.
This need not be a large bore pipe, as the glycerine is generally added to the
mixed acids in a thin stream (an injector is often used).
[Footnote A: Thus if 92 lbs. glycerine give 227 lbs. nitro-glycerine, (277
x 1)/92 = 2.47 lbs.]
[Illustration: FIG. 5.—TOP OF NITRATOR. A, Fume Pipe; B, Water
Pipes for Cooling; C, Acid Mixture Pipe; E, Compressed Air; G, Glycerine
Pipe and Funnel; T, Thermometer; W, Window.]
Page 40
Before the apparatus is ready for use, it requires to have two
thermometers fixed, one long one to reach to the bottom of the tank, and
one short one just long enough to dip under the surface of the acids. When
the tank contains its charge, the former gives the temperature of the bottom,
and the latter of the top of the mixture. The glycerine should be contained in
a small cistern, fixed in some convenient spot upon the wall of the nitrating
house, and should have a pipe let in flush with the bottom, and going
through the dome of the nitrating apparatus. It must of course be provided
with a tap or stop-cock, which should be placed just above the point where
the pipe goes through the lead dome.
Some method of measuring the quantity of glycerine used must be
adopted. A gauge-tube graduated in inches is a very good plan, but it is
essential that the graduations should be clearly visible to the operator upon
the platform in front of the apparatus. A large tap made of earthenware (and
covered with lead) is fixed in the side of the nitrating tank just above the
bottom, to run off the charge after nitration. This should be so arranged that
the charge may be at option run down the conduit to the next house or
discharged into a drowning tank, which may sometimes be necessary in
cases of decomposition. The drowning tank is generally some 3 or 4 yards
long and several feet deep, lined with cement, and placed close outside the
building.
The apparatus having received a charge of mixed acids, the water is
started running through the pipes coiled inside the tank, and a slight
pressure of compressed air is turned on,[A] to mix the acids up well before
starting. The nitration should not be commenced until the two thermometers
register a temperature of 18° C. The glycerine tap is then partially opened,
and the glycerine slowly admitted, and the compressed air turned on full,
until the contents of the apparatus are in a state of very brisk agitation. A
pressure of about 40 lbs. is about the minimum (if 247 lbs. of glycerine and
thermometers fixed, one long one to reach to the bottom of the tank, and
one short one just long enough to dip under the surface of the acids. When
the tank contains its charge, the former gives the temperature of the bottom,
and the latter of the top of the mixture. The glycerine should be contained in
a small cistern, fixed in some convenient spot upon the wall of the nitrating
house, and should have a pipe let in flush with the bottom, and going
through the dome of the nitrating apparatus. It must of course be provided
with a tap or stop-cock, which should be placed just above the point where
the pipe goes through the lead dome.
Some method of measuring the quantity of glycerine used must be
adopted. A gauge-tube graduated in inches is a very good plan, but it is
essential that the graduations should be clearly visible to the operator upon
the platform in front of the apparatus. A large tap made of earthenware (and
covered with lead) is fixed in the side of the nitrating tank just above the
bottom, to run off the charge after nitration. This should be so arranged that
the charge may be at option run down the conduit to the next house or
discharged into a drowning tank, which may sometimes be necessary in
cases of decomposition. The drowning tank is generally some 3 or 4 yards
long and several feet deep, lined with cement, and placed close outside the
building.
The apparatus having received a charge of mixed acids, the water is
started running through the pipes coiled inside the tank, and a slight
pressure of compressed air is turned on,[A] to mix the acids up well before
starting. The nitration should not be commenced until the two thermometers
register a temperature of 18° C. The glycerine tap is then partially opened,
and the glycerine slowly admitted, and the compressed air turned on full,
until the contents of the apparatus are in a state of very brisk agitation. A
pressure of about 40 lbs. is about the minimum (if 247 lbs. of glycerine and
Page 41
16 cwt. of acids are in the tank). If the glycerine tube is fitted with an
injector, it may be turned on almost at once. The nitration will take about
thirty minutes to complete, but the compressed air and water should be kept
on for an additional ten minutes after this, to give time for all the glycerine
to nitrate. The temperature should be kept as low as possible (not above 18°
C.).
[Footnote A: At the Halton Factory, Germany, cylinders of compressed
carbon dioxide are connected with the air pipes so that in the event of a
failure of the air supply the stirring can be continued with this gas if
necessary.]
The chief points to attend to during the progress of the nitration are—
1. The temperature registered by the two thermometers.
2. The colour of the nitrous fumes given off (as seen through the little
window in the dome of the apparatus).
3. The pressure of the compressed air as seen from a gauge fixed upon
the air pipe just before it enters the apparatus.
4. The gauge showing the quantity of glycerine used. The temperature, as
shown by either of the two thermometers, should not be at any time higher
than 25° C.
If it rises much above this point, the glycerine should be at once shut off,
and the pressure of air increased for some few minutes until the temperature
falls, and no more red fumes are given off.
The nitration being finished, the large earthenware tap at the bottom of
the tank is opened, and the charge allowed to flow away down the conduit
to the next building, i.e., to the separator.
injector, it may be turned on almost at once. The nitration will take about
thirty minutes to complete, but the compressed air and water should be kept
on for an additional ten minutes after this, to give time for all the glycerine
to nitrate. The temperature should be kept as low as possible (not above 18°
C.).
[Footnote A: At the Halton Factory, Germany, cylinders of compressed
carbon dioxide are connected with the air pipes so that in the event of a
failure of the air supply the stirring can be continued with this gas if
necessary.]
The chief points to attend to during the progress of the nitration are—
1. The temperature registered by the two thermometers.
2. The colour of the nitrous fumes given off (as seen through the little
window in the dome of the apparatus).
3. The pressure of the compressed air as seen from a gauge fixed upon
the air pipe just before it enters the apparatus.
4. The gauge showing the quantity of glycerine used. The temperature, as
shown by either of the two thermometers, should not be at any time higher
than 25° C.
If it rises much above this point, the glycerine should be at once shut off,
and the pressure of air increased for some few minutes until the temperature
falls, and no more red fumes are given off.
The nitration being finished, the large earthenware tap at the bottom of
the tank is opened, and the charge allowed to flow away down the conduit
to the next building, i.e., to the separator.
Page 42
The nitrating house is best built of wood, and should have a close-
boarded floor, which should be kept scrupulously clean, and free from grit
and sand. A wooden pail and a sponge should be kept in the house in order
that the workman may at once clean up any mess that may be made, and a
small broom should be handy, in order that any sand, &c., may be at once
removed. It is a good plan for the nitrator to keep a book in which he
records the time of starting each nitration, the temperature at starting and at
the finish, the time occupied, and the date and number of the charge, as this
enables the foreman of the danger area at any time to see how many charges
have been nitrated, and gives him other useful information conducive to
safe working. Edward Liebert has devised an improvement in the treatment
of nitro-glycerine. He adds ammonium sulphate or ammonium nitrate to the
mixed acids during the operation of nitrating, which he claims destroys the
nitrous acid formed according to the equation—
(NH_{4}){2}SO{4} + 2HNO_{3} = H_{2}SO_{4} + 2N_{2} + 4H_{2}O.
I am not aware that this modification of the process of nitration is in use
at the present time.
The newly made charge of nitro-glycerine, upon leaving the nitrating
house, flows away down the conduit, either made of rubber pipes, or better
still, of woodwork, lined with lead and covered with lids made of wood (in
short lengths), in order that by lifting them at any point the condition of the
conduit can be examined, as this is of the greatest importance, and the
conduit requires to be frequently washed out and the sulphate of lead
removed. This sulphate always contains nitro-glycerine, and should
therefore be burnt in some spot far removed from any danger building or
magazine, as it frequently explodes with considerable violence.
[Illustration: FIG. 6.—SMALL NITRATOR. N, Tap for Discharging; P,
Water Pipes; T, Thermometer; W, Windows; P', Glycerine Pipe.]
boarded floor, which should be kept scrupulously clean, and free from grit
and sand. A wooden pail and a sponge should be kept in the house in order
that the workman may at once clean up any mess that may be made, and a
small broom should be handy, in order that any sand, &c., may be at once
removed. It is a good plan for the nitrator to keep a book in which he
records the time of starting each nitration, the temperature at starting and at
the finish, the time occupied, and the date and number of the charge, as this
enables the foreman of the danger area at any time to see how many charges
have been nitrated, and gives him other useful information conducive to
safe working. Edward Liebert has devised an improvement in the treatment
of nitro-glycerine. He adds ammonium sulphate or ammonium nitrate to the
mixed acids during the operation of nitrating, which he claims destroys the
nitrous acid formed according to the equation—
(NH_{4}){2}SO{4} + 2HNO_{3} = H_{2}SO_{4} + 2N_{2} + 4H_{2}O.
I am not aware that this modification of the process of nitration is in use
at the present time.
The newly made charge of nitro-glycerine, upon leaving the nitrating
house, flows away down the conduit, either made of rubber pipes, or better
still, of woodwork, lined with lead and covered with lids made of wood (in
short lengths), in order that by lifting them at any point the condition of the
conduit can be examined, as this is of the greatest importance, and the
conduit requires to be frequently washed out and the sulphate of lead
removed. This sulphate always contains nitro-glycerine, and should
therefore be burnt in some spot far removed from any danger building or
magazine, as it frequently explodes with considerable violence.
[Illustration: FIG. 6.—SMALL NITRATOR. N, Tap for Discharging; P,
Water Pipes; T, Thermometer; W, Windows; P', Glycerine Pipe.]
Page 43
In works where the manufacture of nitro-glycerine is of secondary
importance, and some explosive containing only perhaps 10 per cent. of
nitroglycerine is manufactured, and where 50 or 100 lbs. of glycerine are
nitrated at one time, a very much smaller nitrating apparatus than the one
that has been already described will be probably all that is required. In this
case the form of apparatus shown in Fig. 6 will be found very satisfactory.
It should be made of stout lead (all lead used for tanks, &c., must be
"chemical lead"), and may be made to hold 50 or 100 lbs. as found most
convenient. This nitrator can very well be placed in the same house as the
separator; in fact, where such a small quantity of nitro- glycerine is
required, the whole series of operations, nitrating, separation, and washing,
&c., may very well be performed in the same building. It will of course be
necessary to place the nitrator on a higher level than the separator, but this
can easily be done by having platforms of different heights, the nitration
being performed upon the highest. The construction of this nitrator is
essentially the same as in the larger one, the shape only being somewhat
different. Two water coils will probably be enough, and one thermometer. It
will not be necessary to cover this form in with woodwork.
~The Nathan Nitrator.~[A]—This nitrator is the patent of Lt. Col. F.L.
Nathan and Messrs J.M. Thomson and W. Rintoul of Waltham Abbey, and
will probably before long entirely supersede all the other forms of nitrator
on account of its efficiency and economy of working. With this nitrator it is
possible to obtain from 2.21 to 2.22 parts of nitro-glycerine from every 1
part of glycerine. The apparatus is so arranged that the nitration of the
glycerine, the separation of nitro-glycerine produced, as well as the
operation of "after-separation," are carried out in one vessel. The usual
nitrating vessel is provided with an acid inlet pipe at the bottom, and a glass
separation cylinder with a lateral exit or overflow pipe at the top. This
cylinder is covered by a glass hood or bell jar during nitration to direct the
escaping air and fumes into a fume pipe where the flow of the latter may be
importance, and some explosive containing only perhaps 10 per cent. of
nitroglycerine is manufactured, and where 50 or 100 lbs. of glycerine are
nitrated at one time, a very much smaller nitrating apparatus than the one
that has been already described will be probably all that is required. In this
case the form of apparatus shown in Fig. 6 will be found very satisfactory.
It should be made of stout lead (all lead used for tanks, &c., must be
"chemical lead"), and may be made to hold 50 or 100 lbs. as found most
convenient. This nitrator can very well be placed in the same house as the
separator; in fact, where such a small quantity of nitro- glycerine is
required, the whole series of operations, nitrating, separation, and washing,
&c., may very well be performed in the same building. It will of course be
necessary to place the nitrator on a higher level than the separator, but this
can easily be done by having platforms of different heights, the nitration
being performed upon the highest. The construction of this nitrator is
essentially the same as in the larger one, the shape only being somewhat
different. Two water coils will probably be enough, and one thermometer. It
will not be necessary to cover this form in with woodwork.
~The Nathan Nitrator.~[A]—This nitrator is the patent of Lt. Col. F.L.
Nathan and Messrs J.M. Thomson and W. Rintoul of Waltham Abbey, and
will probably before long entirely supersede all the other forms of nitrator
on account of its efficiency and economy of working. With this nitrator it is
possible to obtain from 2.21 to 2.22 parts of nitro-glycerine from every 1
part of glycerine. The apparatus is so arranged that the nitration of the
glycerine, the separation of nitro-glycerine produced, as well as the
operation of "after-separation," are carried out in one vessel. The usual
nitrating vessel is provided with an acid inlet pipe at the bottom, and a glass
separation cylinder with a lateral exit or overflow pipe at the top. This
cylinder is covered by a glass hood or bell jar during nitration to direct the
escaping air and fumes into a fume pipe where the flow of the latter may be
Page 44
assisted by an air injector. The lateral pipe in the separation cylinder is in
connection with a funnel leading to the prewash tank. The drawing (Fig. 7)
shows a vertical section of the apparatus; a is the nitrating vessel of usual
construction, having at the bottom an acid inlet pipe with three branches,
one leading to the de-nitrating plant, c leading to the drowning tank, and d,
which extends upwards and has two branches, e leading to the nitrating
acids tank, and f to the waste acid tank. On the sloped bottom of the
nitrating vessel a lies a coil g of perforated pipe for blowing air, and there
are in the vessel several coils h, three shown in the drawing, for circulation
of cooling water. At the top of the vessel there is a glass cylinder i, having a
lateral outlet j directed into the funnel mouth of a pipe k leading to the
prewash tank. Over the cylinder i is a glass globe l, into which opens a pipe
m for leading off fumes which may be promoted by a compressed air jet
from a pipe r operating as an injector. Into an opening of the glass dome l is
inserted a vessel n, which is connected by a flexible pipe p to the glycerine
tank, and from the bottom of n, which is perforated and covered with a disc
perforated with holes registering with those through the bottom, this disc
being connected by a stem with a knob q by which it can be turned so as to
throttle or cut off passage of glycerine through the bottom. s is a
thermometer for indicating the temperature of the contents of the vessel.
[Footnote A: Eng. Pat. 15,983, August 1901.]
[Illustration: FIG. 7.—NATHAN'S NITRATOR FOR NITRO-
GLYCERINE. (a) Nitrating Vessel; (b) to Separating Vessel; (c) to
Drowning Tank; (e) Nitrating Acids enter (f) to the Waste Acids; (g) Coils
for Compressed Air; (h) Pipes for Cooling Water; (i) Glass Cylinder; (j)
Outlet to k; (k) leading to Prewash Tank; (l) Glass Dome; (m) Pipe to lead
off for Escape of Fumes; (n) Vessel; (p) Pipe conveying Glycerine; (q)
Knob to turn off Glycerine; (r) Compressed Air Jet; (s) Thermometer.]
connection with a funnel leading to the prewash tank. The drawing (Fig. 7)
shows a vertical section of the apparatus; a is the nitrating vessel of usual
construction, having at the bottom an acid inlet pipe with three branches,
one leading to the de-nitrating plant, c leading to the drowning tank, and d,
which extends upwards and has two branches, e leading to the nitrating
acids tank, and f to the waste acid tank. On the sloped bottom of the
nitrating vessel a lies a coil g of perforated pipe for blowing air, and there
are in the vessel several coils h, three shown in the drawing, for circulation
of cooling water. At the top of the vessel there is a glass cylinder i, having a
lateral outlet j directed into the funnel mouth of a pipe k leading to the
prewash tank. Over the cylinder i is a glass globe l, into which opens a pipe
m for leading off fumes which may be promoted by a compressed air jet
from a pipe r operating as an injector. Into an opening of the glass dome l is
inserted a vessel n, which is connected by a flexible pipe p to the glycerine
tank, and from the bottom of n, which is perforated and covered with a disc
perforated with holes registering with those through the bottom, this disc
being connected by a stem with a knob q by which it can be turned so as to
throttle or cut off passage of glycerine through the bottom. s is a
thermometer for indicating the temperature of the contents of the vessel.
[Footnote A: Eng. Pat. 15,983, August 1901.]
[Illustration: FIG. 7.—NATHAN'S NITRATOR FOR NITRO-
GLYCERINE. (a) Nitrating Vessel; (b) to Separating Vessel; (c) to
Drowning Tank; (e) Nitrating Acids enter (f) to the Waste Acids; (g) Coils
for Compressed Air; (h) Pipes for Cooling Water; (i) Glass Cylinder; (j)
Outlet to k; (k) leading to Prewash Tank; (l) Glass Dome; (m) Pipe to lead
off for Escape of Fumes; (n) Vessel; (p) Pipe conveying Glycerine; (q)
Knob to turn off Glycerine; (r) Compressed Air Jet; (s) Thermometer.]
Page 45
In operating with this apparatus the nitrating acid is introduced into the
nitrating vessel by opening the cock of the pipe e. The glycerine is then run
in by introducing n and opening the valve at its bottom, the contents of the
vessel being agitated by air blown through the perforations of the pipe g.
When the glycerine is all nitrated and the temperature has slightly fallen,
the circulation of the water through the coils h and the air-stirring are
stopped, and the glycerine supply vessel n is removed. The nitro-glycerine
as it separates from the acids is raised by introducing by the pipe f waste
acid from a previous charge, this displacing the nitro-glycerine upwards and
causing it to flow by the outlet, j and pipe k to the prewash tank. When
nearly all the nitro-glycerine has been separated in this manner the acids in
the apparatus may be run off by the pipe b to an after separating vessel for
further settling, thus leaving the apparatus free for another nitration, or the
nitrating vessel itself may be used as an after separating bottle displacing
the nitro-glycerine with waste acid as it rises to the top, or skimming off in
the usual manner. When the separation of the nitro- glycerine is complete
the waste acid is run off and denitrated as usual, a portion of it being
reserved for the displacement of the nitro-glycerine in a subsequent
operation.
In a further patent (Eng. Pat. 3,020, 1903) the authors propose with the
object of preventing the formation and separation of nitro-glycerine in the
waste acids, after the nitro-glycerine initially formed in the nitrating vessel
has been separated and removed, to add a small quantity of water to the
waste acids; this is carried out as follows. A relatively small quantity of
water is added, and this prevents all further separation of nitro-glycerine,
and at the same time the strength of the waste acids is so slightly reduced
that their separation and re-concentration are not affected. "After-
separation" is thus done away with, and the nitro- glycerine plant simplified
and its output increased. After nitration separation is commenced at a
temperature such that when all the displacing acid has been added, and the
nitrating vessel by opening the cock of the pipe e. The glycerine is then run
in by introducing n and opening the valve at its bottom, the contents of the
vessel being agitated by air blown through the perforations of the pipe g.
When the glycerine is all nitrated and the temperature has slightly fallen,
the circulation of the water through the coils h and the air-stirring are
stopped, and the glycerine supply vessel n is removed. The nitro-glycerine
as it separates from the acids is raised by introducing by the pipe f waste
acid from a previous charge, this displacing the nitro-glycerine upwards and
causing it to flow by the outlet, j and pipe k to the prewash tank. When
nearly all the nitro-glycerine has been separated in this manner the acids in
the apparatus may be run off by the pipe b to an after separating vessel for
further settling, thus leaving the apparatus free for another nitration, or the
nitrating vessel itself may be used as an after separating bottle displacing
the nitro-glycerine with waste acid as it rises to the top, or skimming off in
the usual manner. When the separation of the nitro- glycerine is complete
the waste acid is run off and denitrated as usual, a portion of it being
reserved for the displacement of the nitro-glycerine in a subsequent
operation.
In a further patent (Eng. Pat. 3,020, 1903) the authors propose with the
object of preventing the formation and separation of nitro-glycerine in the
waste acids, after the nitro-glycerine initially formed in the nitrating vessel
has been separated and removed, to add a small quantity of water to the
waste acids; this is carried out as follows. A relatively small quantity of
water is added, and this prevents all further separation of nitro-glycerine,
and at the same time the strength of the waste acids is so slightly reduced
that their separation and re-concentration are not affected. "After-
separation" is thus done away with, and the nitro- glycerine plant simplified
and its output increased. After nitration separation is commenced at a
temperature such that when all the displacing acid has been added, and the
Page 46
separation of the nitro-glycerine is complete, the temperature of the
contents of the nitrating vessel shall not be lower than 15° C. A sufficient
quantity of the displacing acid is then run off through the waste-acid cock to
allow of the remaining acids being air-stirred without splashing over the
top. A small quantity of water, from 2 to 3 per cent. according to strength of
acid; if waste consists of sulphuric acid (monohydrate), 62 per cent.; nitric
acid (anhydrous), 33 per cent. and water 5 per cent.; temperature 15° C.,
then 2 per cent. of water is added; if waste acids contain less than 4 per
cent. of water of temperature lower than 15° C., from 3 to 5 per cent. of
water may have to be added. The water is added slowly through the
separator cylinder, and the contents of the nitrator air-stirred, but not
cooled, the temperature being allowed to rise slowly and regularly as the
water is added—usually about 3° C. for each per cent. of water added.
When air-agitation has been stopped, the acids are kept at rest for a short
time, in order to allow of any small quantity of initially formed nitro-
glycerine adhering to the coils and sides of the vessel rising to the top.
When this has been separated by displacement, the acids are ready for
denitration, or can be safely stored without further precaution.
~Separation.~—The nitro-glycerine, together with the mixed acids, flows
from the nitrating house to the separating house, which must be on a lower
level than the former. The separating house contains a large lead-lined tank,
closed in at the top with a wooden lid, into which a lead pipe of large bore
is fixed, and which is carried up through the roof of the building, and acts as
a chimney to carry off any fumes. A little glass window should be fixed in
this pipe in order that the colour of the escaping fumes may be seen. The
conduit conveying the nitro-glycerine enters the building close under the
roof, and discharges its contents into the tank through the pipe G (Fig. 8).
The tank is only about two-thirds filled by the charge. There is in the side of
the tank a small window of thick plate glass, which enables the workman to
contents of the nitrating vessel shall not be lower than 15° C. A sufficient
quantity of the displacing acid is then run off through the waste-acid cock to
allow of the remaining acids being air-stirred without splashing over the
top. A small quantity of water, from 2 to 3 per cent. according to strength of
acid; if waste consists of sulphuric acid (monohydrate), 62 per cent.; nitric
acid (anhydrous), 33 per cent. and water 5 per cent.; temperature 15° C.,
then 2 per cent. of water is added; if waste acids contain less than 4 per
cent. of water of temperature lower than 15° C., from 3 to 5 per cent. of
water may have to be added. The water is added slowly through the
separator cylinder, and the contents of the nitrator air-stirred, but not
cooled, the temperature being allowed to rise slowly and regularly as the
water is added—usually about 3° C. for each per cent. of water added.
When air-agitation has been stopped, the acids are kept at rest for a short
time, in order to allow of any small quantity of initially formed nitro-
glycerine adhering to the coils and sides of the vessel rising to the top.
When this has been separated by displacement, the acids are ready for
denitration, or can be safely stored without further precaution.
~Separation.~—The nitro-glycerine, together with the mixed acids, flows
from the nitrating house to the separating house, which must be on a lower
level than the former. The separating house contains a large lead-lined tank,
closed in at the top with a wooden lid, into which a lead pipe of large bore
is fixed, and which is carried up through the roof of the building, and acts as
a chimney to carry off any fumes. A little glass window should be fixed in
this pipe in order that the colour of the escaping fumes may be seen. The
conduit conveying the nitro-glycerine enters the building close under the
roof, and discharges its contents into the tank through the pipe G (Fig. 8).
The tank is only about two-thirds filled by the charge. There is in the side of
the tank a small window of thick plate glass, which enables the workman to
Page 47
see the level of the charge, and also to observe the progress of the
separation, which will take from thirty minutes to one hour.
The tank should be in connection with a drowning tank, as the charge
sometimes gets very dangerous in this building. It must also be connected
by a conduit with the filter house, and also to the secondary separator by
another conduit. The tank should also be fitted with a compressed air pipe,
bent in the form of a loop. It should lie upon the bottom of the vat. The
object of this is to mix up the charge in case it should get too hot through
decomposition. A thermometer should of course be fixed in the lid of the
tank, and its bulb should reach down to the middle of the nitro-glycerine
(which rests upon the surface of the mixed acids, the specific gravity of the
nitro-glycerine being 1.6, and that of the waste acids 1.7; the composition of
the acids is now 11 per cent. HNO_{3}, 67 per cent. H_{2}SO_{4}, and 22
per cent. water), and the temperature carefully watched.
[Illustration: FIG. 8.—SEPARATOR. A, Compressed Air Pipes; G, Nitro-
glycerine enters from Nitrator; N, Nitro-glycerine to P; L, Lantern
Window; W, Window in Side; S, Waste Acids to Secondary Separator; T,
Tap to remove last traces of Nitro-glycerine; P, Lead Washing Tank; A,
Compressed Air; W, Water Pipe; N, Nitro-glycerine from Separator.]
If nothing unusual occurs, and it has not been necessary to bring the
compressed air into use, and so disturb the process of separation, the waste
acids may be run away from beneath the nitro-glycerine, and allowed to
flow away to the secondary separator, where any further quantity of nitro-
glycerine that they contain separates out after resting for some days. The
nitro-glycerine itself is run into a smaller tank in the same house, where it is
washed three or four times with its own bulk of water, containing about 3
lbs. of carbonate of soda to neutralise the remaining acid. This smaller tank
should contain a lead pipe, pierced and coiled upon the bottom, through
separation, which will take from thirty minutes to one hour.
The tank should be in connection with a drowning tank, as the charge
sometimes gets very dangerous in this building. It must also be connected
by a conduit with the filter house, and also to the secondary separator by
another conduit. The tank should also be fitted with a compressed air pipe,
bent in the form of a loop. It should lie upon the bottom of the vat. The
object of this is to mix up the charge in case it should get too hot through
decomposition. A thermometer should of course be fixed in the lid of the
tank, and its bulb should reach down to the middle of the nitro-glycerine
(which rests upon the surface of the mixed acids, the specific gravity of the
nitro-glycerine being 1.6, and that of the waste acids 1.7; the composition of
the acids is now 11 per cent. HNO_{3}, 67 per cent. H_{2}SO_{4}, and 22
per cent. water), and the temperature carefully watched.
[Illustration: FIG. 8.—SEPARATOR. A, Compressed Air Pipes; G, Nitro-
glycerine enters from Nitrator; N, Nitro-glycerine to P; L, Lantern
Window; W, Window in Side; S, Waste Acids to Secondary Separator; T,
Tap to remove last traces of Nitro-glycerine; P, Lead Washing Tank; A,
Compressed Air; W, Water Pipe; N, Nitro-glycerine from Separator.]
If nothing unusual occurs, and it has not been necessary to bring the
compressed air into use, and so disturb the process of separation, the waste
acids may be run away from beneath the nitro-glycerine, and allowed to
flow away to the secondary separator, where any further quantity of nitro-
glycerine that they contain separates out after resting for some days. The
nitro-glycerine itself is run into a smaller tank in the same house, where it is
washed three or four times with its own bulk of water, containing about 3
lbs. of carbonate of soda to neutralise the remaining acid. This smaller tank
should contain a lead pipe, pierced and coiled upon the bottom, through
Page 48
which compressed air may be passed, in order to stir up the charge with the
water and soda. After this preliminary washing, the nitro-glycerine is drawn
off into indiarubber buckets, and poured down the conduit to the filter
house. The wash waters may be sent down a conduit to another building, in
order to allow the small quantity of nitro-glycerine that has been retained in
the water as minute globules to settle, if thought worth the trouble of
saving. This, of course, will depend upon the usual out-turn of nitro-
glycerine in a day, and the general scale of operations.
[Illustration: FIG. 9.—FILTERING AND WASHING PLANT. W, Lead
Washing
Tank; WP, Water Pipe; L, Lid; S, Nitro-glycerine from Separator; A,
B, C, Filtering Tanks; B2, Indiarubber Bucket.]
~Filtering and Washing.~—The filter house (Fig. 9), which must of
course be again on a somewhat lower level than the separating house, must
be a considerably larger building than either the nitrating or separating
houses, as it is always necessary to be washing some five or six charges at
the same time. Upon the arrival of the nitro-glycerine at this house, it first
flows into a lead-lined wooden tank (W), containing a compressed air pipe,
just like the one in the small tank in the separating house. This tank is half
filled with water, and the compressed air is turned on from half to a quarter
of an hour after the introduction of the charge. The water is then drawn off,
and fresh water added. Four or five washings are generally necessary. The
nitro-glycerine is then run into the next tank (A), the top of which is on a
level with the bottom of the first one. Across the top of this tank is stretched
a frame of flannel, through which the nitroglycerine has to filter. This
removes any solid matters, such as dirt or scum. Upon leaving this tank, it
passes through a similar flannel frame across another tank (B), and is finally
drawn off by a tap in the bottom of the tank into rubber buckets. The taps in
these tanks are best made of vulcanite.
water and soda. After this preliminary washing, the nitro-glycerine is drawn
off into indiarubber buckets, and poured down the conduit to the filter
house. The wash waters may be sent down a conduit to another building, in
order to allow the small quantity of nitro-glycerine that has been retained in
the water as minute globules to settle, if thought worth the trouble of
saving. This, of course, will depend upon the usual out-turn of nitro-
glycerine in a day, and the general scale of operations.
[Illustration: FIG. 9.—FILTERING AND WASHING PLANT. W, Lead
Washing
Tank; WP, Water Pipe; L, Lid; S, Nitro-glycerine from Separator; A,
B, C, Filtering Tanks; B2, Indiarubber Bucket.]
~Filtering and Washing.~—The filter house (Fig. 9), which must of
course be again on a somewhat lower level than the separating house, must
be a considerably larger building than either the nitrating or separating
houses, as it is always necessary to be washing some five or six charges at
the same time. Upon the arrival of the nitro-glycerine at this house, it first
flows into a lead-lined wooden tank (W), containing a compressed air pipe,
just like the one in the small tank in the separating house. This tank is half
filled with water, and the compressed air is turned on from half to a quarter
of an hour after the introduction of the charge. The water is then drawn off,
and fresh water added. Four or five washings are generally necessary. The
nitro-glycerine is then run into the next tank (A), the top of which is on a
level with the bottom of the first one. Across the top of this tank is stretched
a frame of flannel, through which the nitroglycerine has to filter. This
removes any solid matters, such as dirt or scum. Upon leaving this tank, it
passes through a similar flannel frame across another tank (B), and is finally
drawn off by a tap in the bottom of the tank into rubber buckets. The taps in
these tanks are best made of vulcanite.
Page 49
At this stage, a sample should be taken to the laboratory and tested. If the
sample will not pass the tests, which is often the case, the charge must be
rewashed for one hour, or some other time, according to the judgment of the
chemist in charge. In the case of an obstinate charge, it is of much more
avail to wash a large number of times with small quantities of water, and for
a short time, than to use a lot of water and wash for half an hour. Plenty of
compressed air should be used, as the compound nitric ethers which are
formed are thus got rid of. As five or six charges are often in this house at
one time, it is necessary to have as many tanks arranged in tiers, otherwise
one or two refractory charges would stop the nitrating house and the rest of
the nitro-glycerine plant. The chief causes of the washed material not
passing the heat test are, either that the acids were not clean, or they
contained objectionable impurities, or more frequently, the quality of the
glycerine used. The glycerine used for making nitro-glycerine should
conform to the following tests, some of which, however, are of greater
importance than others. The glycerine should—
1. Have minimum specific gravity at 15° C. of 1.261.
2. Should nitrify well.
3. Separation should be sharp within half an hour, without the separation
of flocculent matter, nor should any white flocculent matter (due to fatty
acids) be formed when the nitrated glycerine is thrown into water and
neutralised with carbonate of soda.
4. Should be free from lime and chlorine, and contain only traces of
arsenic, sulphuric acid, &c.
5. Should not leave more than 0.25 per cent. of inorganic and organic
residue together when evaporated in a platinum dish without ebullition
(about 160° C.) or partial decomposition.
sample will not pass the tests, which is often the case, the charge must be
rewashed for one hour, or some other time, according to the judgment of the
chemist in charge. In the case of an obstinate charge, it is of much more
avail to wash a large number of times with small quantities of water, and for
a short time, than to use a lot of water and wash for half an hour. Plenty of
compressed air should be used, as the compound nitric ethers which are
formed are thus got rid of. As five or six charges are often in this house at
one time, it is necessary to have as many tanks arranged in tiers, otherwise
one or two refractory charges would stop the nitrating house and the rest of
the nitro-glycerine plant. The chief causes of the washed material not
passing the heat test are, either that the acids were not clean, or they
contained objectionable impurities, or more frequently, the quality of the
glycerine used. The glycerine used for making nitro-glycerine should
conform to the following tests, some of which, however, are of greater
importance than others. The glycerine should—
1. Have minimum specific gravity at 15° C. of 1.261.
2. Should nitrify well.
3. Separation should be sharp within half an hour, without the separation
of flocculent matter, nor should any white flocculent matter (due to fatty
acids) be formed when the nitrated glycerine is thrown into water and
neutralised with carbonate of soda.
4. Should be free from lime and chlorine, and contain only traces of
arsenic, sulphuric acid, &c.
5. Should not leave more than 0.25 per cent. of inorganic and organic
residue together when evaporated in a platinum dish without ebullition
(about 160° C.) or partial decomposition.
Page 50
6. Silver test fair.
7. The glycerine, when diluted one-half, should give no deposit or
separation of fatty acids when nitric peroxide gas is passed through it. (Nos.
1, 2, 3, and 5 are the most essential.)
The white flocculent matter sometimes formed is a very great nuisance,
and any sample of glycerol which gives such a precipitate when tried in the
laboratory should at once be rejected, as it will give no end of trouble in the
separating house, and also in the filter house, and it will be very difficult
indeed to make the nitro-glycerine pass the heat test. The out- turn of nitro-
glycerine also will be very low. The trouble will show itself chiefly in the
separating operation. Very often 2 or 3 inches will rise to the surface or
hang about in the nitro-glycerine, and at the point of contact between it and
the mixed acids, and will afterwards be very difficult to get rid of by
filtration. The material appears to be partly an emulsion of the glycerine,
and partly due to fatty acids, and as there appears to be no really
satisfactory method of preventing its formation, or of getting rid of it, the
better plan is not to use any glycerine for nitrating that has been found by
experiment upon the laboratory scale to give this objectionable matter. One
of the most useful methods of testing the glycerine, other than nitrating, is
to dilute the sample one-half with water, and then to pass a current of nitric
peroxide gas through it, when a flocculent precipitate of elaïdic acid (less
soluble in glycerine than the original oleic acid) will be formed. Nitrogen
peroxide, N_{2}O_{4}, is best obtained by heating dry lead nitrate (see
Allen, "Commercial Organic Analysis," vol. ii., 301).
When a sample of nitro-glycerine is brought to the laboratory from the
filter house, it should first be examined to see that it is not acid.[A] A weak
solution of Congo red or methyl orange may be used. If it appears to be
decidedly alkaline, it should be poured into a separating funnel, and shaken
7. The glycerine, when diluted one-half, should give no deposit or
separation of fatty acids when nitric peroxide gas is passed through it. (Nos.
1, 2, 3, and 5 are the most essential.)
The white flocculent matter sometimes formed is a very great nuisance,
and any sample of glycerol which gives such a precipitate when tried in the
laboratory should at once be rejected, as it will give no end of trouble in the
separating house, and also in the filter house, and it will be very difficult
indeed to make the nitro-glycerine pass the heat test. The out- turn of nitro-
glycerine also will be very low. The trouble will show itself chiefly in the
separating operation. Very often 2 or 3 inches will rise to the surface or
hang about in the nitro-glycerine, and at the point of contact between it and
the mixed acids, and will afterwards be very difficult to get rid of by
filtration. The material appears to be partly an emulsion of the glycerine,
and partly due to fatty acids, and as there appears to be no really
satisfactory method of preventing its formation, or of getting rid of it, the
better plan is not to use any glycerine for nitrating that has been found by
experiment upon the laboratory scale to give this objectionable matter. One
of the most useful methods of testing the glycerine, other than nitrating, is
to dilute the sample one-half with water, and then to pass a current of nitric
peroxide gas through it, when a flocculent precipitate of elaïdic acid (less
soluble in glycerine than the original oleic acid) will be formed. Nitrogen
peroxide, N_{2}O_{4}, is best obtained by heating dry lead nitrate (see
Allen, "Commercial Organic Analysis," vol. ii., 301).
When a sample of nitro-glycerine is brought to the laboratory from the
filter house, it should first be examined to see that it is not acid.[A] A weak
solution of Congo red or methyl orange may be used. If it appears to be
decidedly alkaline, it should be poured into a separating funnel, and shaken
Page 51
with a little distilled water. This should be repeated, and the washings
(about 400 c.c.) run into a beaker, a drop of Congo red or methyl orange
added, and a drop or so of N/2 hydrochloric acid added, when it should
give, with two or three drops at most, a blue colour with the Congo red, or
pink with the methyl orange, &c. The object of this test is to show that the
nitro-glycerine is free from any excess of soda, i.e., that the soda has been
properly washed out, otherwise the heat test will show the sample to be
better than it is. The heat test must also be applied.
[Footnote A: A. Leroux, Bul. Soc. Chim. de Bel., xix., August 1905,
contends that experience does not warrant the assumption that free acid is a
source of danger in nitro-glycerine or nitro-cellulose; free alkali, he states,
promotes their decomposition.]
Upon leaving the filter house, where it has been washed and filtered, and
has satisfactorily passed the heat test, it is drawn off from the lowest tank in
indiarubber buckets, and poured down the conduit leading to the
precipitating house, where it is allowed to stand for a day, or sometimes
longer, in order to allow the little water it still contains to rise to the surface.
In order to accomplish this, it is sufficient to allow it to stand in covered-in
tanks of a conical form, and about 3 or 4 feet high. In many works it is
previously filtered through common salt, which of course absorbs the last
traces of water. It is then of a pale yellow colour, and should be quite clear,
and can be drawn off by means of a tap (of vulcanite), fixed at the bottom
of the tanks, into rubber buckets, and is ready for use in the preparation of
dynamite, or any of the various forms of gelatine compounds, smokeless
powders, &c., such as cordite, ballistite, and many others.
Mikolajezak (Chem. Zeit., 1904, Rep. 174) states that he has prepared
mono- and di-nitro-glycerine, and believes that the latter compound will
form a valuable basis for explosives, as it is unfreezable. It is stated to be an
(about 400 c.c.) run into a beaker, a drop of Congo red or methyl orange
added, and a drop or so of N/2 hydrochloric acid added, when it should
give, with two or three drops at most, a blue colour with the Congo red, or
pink with the methyl orange, &c. The object of this test is to show that the
nitro-glycerine is free from any excess of soda, i.e., that the soda has been
properly washed out, otherwise the heat test will show the sample to be
better than it is. The heat test must also be applied.
[Footnote A: A. Leroux, Bul. Soc. Chim. de Bel., xix., August 1905,
contends that experience does not warrant the assumption that free acid is a
source of danger in nitro-glycerine or nitro-cellulose; free alkali, he states,
promotes their decomposition.]
Upon leaving the filter house, where it has been washed and filtered, and
has satisfactorily passed the heat test, it is drawn off from the lowest tank in
indiarubber buckets, and poured down the conduit leading to the
precipitating house, where it is allowed to stand for a day, or sometimes
longer, in order to allow the little water it still contains to rise to the surface.
In order to accomplish this, it is sufficient to allow it to stand in covered-in
tanks of a conical form, and about 3 or 4 feet high. In many works it is
previously filtered through common salt, which of course absorbs the last
traces of water. It is then of a pale yellow colour, and should be quite clear,
and can be drawn off by means of a tap (of vulcanite), fixed at the bottom
of the tanks, into rubber buckets, and is ready for use in the preparation of
dynamite, or any of the various forms of gelatine compounds, smokeless
powders, &c., such as cordite, ballistite, and many others.
Mikolajezak (Chem. Zeit., 1904, Rep. 174) states that he has prepared
mono- and di-nitro-glycerine, and believes that the latter compound will
form a valuable basis for explosives, as it is unfreezable. It is stated to be an
Page 52
odourless, unfreezable oil, less sensitive to percussion, friction, and increase
of temperature, and to possess a greater solvent power for collodion-cotton
than ordinary nitro-glycerine. It can thus be used for the preparation of
explosives of high stability, which will maintain their plastic nature even in
winter. The di-nitro-glycerine is a solvent for tri-nitro-glycerine, it can
therefore be mixed with this substance, in the various gelatine explosives in
order to lower the freezing point.
~The Waste Acids.~—The waste acids from the separating house, from
which the nitro-glycerine has been as completely separated as possible, are
run down the conduit to the secondary separator, in order to recover the last
traces of nitro-glycerine that they contain. The composition of the waste
acids is generally somewhat as follows:—Specific gravity, 1.7075 at 15° C.;
sulphuric acid, 67.2 per cent.; nitric acid, 11.05 per cent.; and water, 21.7
per cent., with perhaps as much as 2 per cent. of nitric oxide, and of course
varying quantities of nitro-glycerine, which must be separated, as it is
impossible to run this liquid away (unless it can be run into the sea) or to
recover the acids by distillation as long as it contains this substance. The
mixture, therefore, is generally run into large circular lead-lined tanks,
covered in, and very much like the nitrating apparatus in construction, that
is, they contain worms coiled round inside, to allow of water being run
through to keep the mixture cool, and a compressed air pipe, in order to
agitate the mixture if necessary. The top also should contain a window, in
order to allow of the interior being seen, and should have a leaden chimney
to carry off the fumes which may arise from decomposition. It is also useful
to have a glass tube of 3 or 4 inches in diameter substituted for about a foot
of the lead chimney, in order that the man on duty can at any time see the
colour of the fumes arising from the liquid. There should also be two
thermometers, one long one reaching to the bottom of the tank, and one to
just a few inches below the surface of the liquid.
of temperature, and to possess a greater solvent power for collodion-cotton
than ordinary nitro-glycerine. It can thus be used for the preparation of
explosives of high stability, which will maintain their plastic nature even in
winter. The di-nitro-glycerine is a solvent for tri-nitro-glycerine, it can
therefore be mixed with this substance, in the various gelatine explosives in
order to lower the freezing point.
~The Waste Acids.~—The waste acids from the separating house, from
which the nitro-glycerine has been as completely separated as possible, are
run down the conduit to the secondary separator, in order to recover the last
traces of nitro-glycerine that they contain. The composition of the waste
acids is generally somewhat as follows:—Specific gravity, 1.7075 at 15° C.;
sulphuric acid, 67.2 per cent.; nitric acid, 11.05 per cent.; and water, 21.7
per cent., with perhaps as much as 2 per cent. of nitric oxide, and of course
varying quantities of nitro-glycerine, which must be separated, as it is
impossible to run this liquid away (unless it can be run into the sea) or to
recover the acids by distillation as long as it contains this substance. The
mixture, therefore, is generally run into large circular lead-lined tanks,
covered in, and very much like the nitrating apparatus in construction, that
is, they contain worms coiled round inside, to allow of water being run
through to keep the mixture cool, and a compressed air pipe, in order to
agitate the mixture if necessary. The top also should contain a window, in
order to allow of the interior being seen, and should have a leaden chimney
to carry off the fumes which may arise from decomposition. It is also useful
to have a glass tube of 3 or 4 inches in diameter substituted for about a foot
of the lead chimney, in order that the man on duty can at any time see the
colour of the fumes arising from the liquid. There should also be two
thermometers, one long one reaching to the bottom of the tank, and one to
just a few inches below the surface of the liquid.
Page 53
The nitro-glycerine, of course, collects upon the surface, and can be
drawn off by a tap placed at a convenient height for the purpose. The cover
of the tank is generally conical, and is joined to a glass cylinder, which is
cemented to the top of this lead cover, and also to the lead chimney. In this
glass cylinder is a hole into which fits a ground glass stopper, through
which the nitro-glycerine can be drawn off. There will probably never be
more than an inch of nitro-glycerine at the most, and seldom that. It should
be taken to the filter house and treated along with another charge. The acids
themselves may either be run to waste, or better treated by some denitration
plant. This house probably requires more attention than any other in the
danger area, on account of the danger of the decomposition of the small
quantities of nitro-glycerine, which, as it is mixed with such a large quantity
of acids and water, is very apt to become hot, and decomposition, which
sets up in spots where a little globule of nitro-glycerine is floating,
surrounded by acids that gradually get hot, gives off nitrous fumes, and
perhaps explodes, and thus causes the sudden explosion of the whole. The
only way to prevent this is for the workman in charge to look at the
thermometers frequently, and at the colour of the escaping fumes, and if he
should notice a rise of temperature or any appearance of red fumes, to turn
on the water and air, and stir up the mixture, when probably the temperature
will suddenly fall, and the fumes cease to come off.
The cause of explosions in this building is either the non-attention of the
workmen in charge, or the bursting of one of the water pipes, by which
means, of course, the water, finding its way into the acids, causes a sudden
rise of temperature. If the latter of these two causes should occur, the water
should at once be shut off and the air turned on full, but if it is seen that an
explosion is likely to occur, the tank should at once be emptied by allowing
its contents to run away into a drowning tank placed close outside the
house, which should be about 4 feet deep, and some 16 feet long by 6 feet
wide; in fact, large enough to hold a considerable quantity of water. But this
drawn off by a tap placed at a convenient height for the purpose. The cover
of the tank is generally conical, and is joined to a glass cylinder, which is
cemented to the top of this lead cover, and also to the lead chimney. In this
glass cylinder is a hole into which fits a ground glass stopper, through
which the nitro-glycerine can be drawn off. There will probably never be
more than an inch of nitro-glycerine at the most, and seldom that. It should
be taken to the filter house and treated along with another charge. The acids
themselves may either be run to waste, or better treated by some denitration
plant. This house probably requires more attention than any other in the
danger area, on account of the danger of the decomposition of the small
quantities of nitro-glycerine, which, as it is mixed with such a large quantity
of acids and water, is very apt to become hot, and decomposition, which
sets up in spots where a little globule of nitro-glycerine is floating,
surrounded by acids that gradually get hot, gives off nitrous fumes, and
perhaps explodes, and thus causes the sudden explosion of the whole. The
only way to prevent this is for the workman in charge to look at the
thermometers frequently, and at the colour of the escaping fumes, and if he
should notice a rise of temperature or any appearance of red fumes, to turn
on the water and air, and stir up the mixture, when probably the temperature
will suddenly fall, and the fumes cease to come off.
The cause of explosions in this building is either the non-attention of the
workmen in charge, or the bursting of one of the water pipes, by which
means, of course, the water, finding its way into the acids, causes a sudden
rise of temperature. If the latter of these two causes should occur, the water
should at once be shut off and the air turned on full, but if it is seen that an
explosion is likely to occur, the tank should at once be emptied by allowing
its contents to run away into a drowning tank placed close outside the
house, which should be about 4 feet deep, and some 16 feet long by 6 feet
wide; in fact, large enough to hold a considerable quantity of water. But this
Page 54
last course should only be resorted to as a last extremity, as it is extremely
troublesome to recover the small quantity of nitro-glycerine from the
bottom of this tank, which is generally a bricked and cemented excavation
some few yards from the house.
It has been proposed to treat these waste acids, containing nitro-
glycerine, in Mr M. Prentice's nitric acid retort. In this case they would be
run into the retort, together with nitrate of soda, in a fine stream, and the
small quantity of nitro-glycerine, coming into contact with the hot mixture
already in the retort, would probably be at once decomposed. This process,
although not yet tried, promises to be a success. Several processes have
been used for the denitration of these acids.
~Treatment of the Waste Acid from the Manufacture of Nitro-Glycerine
and
Gun-Cotton.~—The composition of these acids is as follows:—
Nitro-glycerine and Gun-cotton
Waste Acid.
Sulphuric acid 70 per cent. 78 per cent.
Nitric acid 10 " 12 "
Water 20 " 10 "
The waste acid from the manufacture of gun-cotton is generally used
direct for the manufacture of nitric acid, as it contains a fairly large amount
of sulphuric acid, and the small amount of nitro-cellulose which it also
generally contains decomposes gradually and without explosion in the
retort. Nitric acid may be first distilled off, the resulting sulphuric acid
being then added to the equivalent amount of nitrate of soda. Nitric acid is
then distilled over and condensed in the usual way. Very often, however, the
waste acid is added direct to the charge of nitrate without previously
troublesome to recover the small quantity of nitro-glycerine from the
bottom of this tank, which is generally a bricked and cemented excavation
some few yards from the house.
It has been proposed to treat these waste acids, containing nitro-
glycerine, in Mr M. Prentice's nitric acid retort. In this case they would be
run into the retort, together with nitrate of soda, in a fine stream, and the
small quantity of nitro-glycerine, coming into contact with the hot mixture
already in the retort, would probably be at once decomposed. This process,
although not yet tried, promises to be a success. Several processes have
been used for the denitration of these acids.
~Treatment of the Waste Acid from the Manufacture of Nitro-Glycerine
and
Gun-Cotton.~—The composition of these acids is as follows:—
Nitro-glycerine and Gun-cotton
Waste Acid.
Sulphuric acid 70 per cent. 78 per cent.
Nitric acid 10 " 12 "
Water 20 " 10 "
The waste acid from the manufacture of gun-cotton is generally used
direct for the manufacture of nitric acid, as it contains a fairly large amount
of sulphuric acid, and the small amount of nitro-cellulose which it also
generally contains decomposes gradually and without explosion in the
retort. Nitric acid may be first distilled off, the resulting sulphuric acid
being then added to the equivalent amount of nitrate of soda. Nitric acid is
then distilled over and condensed in the usual way. Very often, however, the
waste acid is added direct to the charge of nitrate without previously
Page 55
eliminating the nitric acid. The treatment of the waste acid from the
manufacture of nitro-glycerine is somewhat different. The small amount of
nitro-glycerine in this acid must always be eliminated. This is effected
either by allowing the waste acid to stand for at least twenty- four hours in a
big vessel with a conical top, where all the nitro- glycerine which will have
separated to the surface is removed by skimming; or, better still, the
"watering down process" of Col. Nathan may be employed. In Nathan's
nitrator every existing trace of nitro-glycerine is separated from the acids in
a few hours after the nitration, and any further formation of nitro-glycerine
is prevented by adding about 2 per cent. of water to the waste acids, which
are kept agitated during the addition. The waste acid, now free from nitro-
glycerine, but which may still contain organic matter, is denitrated by
bringing it into contact with a jet of steam. The waste acid is passed in a
small stream down through a tower of acid-resisting stoneware (volvic
stone), which is closely packed with earthenware, and at the bottom of
which is the steam jet. Decomposition proceeds as the acid meets the steam,
nitric and nitrous acids are disengaged and are passed out at the top of the
tower through a pipe to a series of condensers and towers, where the nitric
acid is collected. The nitrous acid may be converted into nitric acid by
introducing a hot compressed air jet into the gases before they pass into the
condensers. Weak sulphuric acid of sp. gr. 1.6 collects in a saucer in which
the tower stands, and is then passed through a cooling worm. The weak
sulphuric acid, now entirely free from nitric and nitrous acids, may be
concentrated to sp. gr. 1.842 and 96 per cent. H_{2}SO_{4} by any of the
well-known processes, e.g., Kessler, Webb, Benker, Delplace, &c., and it
may be used again in the manufacture of nitro-glycerine or gun-cotton.
Two points in the manufacture of nitro-glycerine are of the greatest
importance, viz., the purity of the glycerine used, and the strength and
purity of the acids used in the nitration. With regard to the first of these,
great care should be taken, and a complete analysis and thorough
manufacture of nitro-glycerine is somewhat different. The small amount of
nitro-glycerine in this acid must always be eliminated. This is effected
either by allowing the waste acid to stand for at least twenty- four hours in a
big vessel with a conical top, where all the nitro- glycerine which will have
separated to the surface is removed by skimming; or, better still, the
"watering down process" of Col. Nathan may be employed. In Nathan's
nitrator every existing trace of nitro-glycerine is separated from the acids in
a few hours after the nitration, and any further formation of nitro-glycerine
is prevented by adding about 2 per cent. of water to the waste acids, which
are kept agitated during the addition. The waste acid, now free from nitro-
glycerine, but which may still contain organic matter, is denitrated by
bringing it into contact with a jet of steam. The waste acid is passed in a
small stream down through a tower of acid-resisting stoneware (volvic
stone), which is closely packed with earthenware, and at the bottom of
which is the steam jet. Decomposition proceeds as the acid meets the steam,
nitric and nitrous acids are disengaged and are passed out at the top of the
tower through a pipe to a series of condensers and towers, where the nitric
acid is collected. The nitrous acid may be converted into nitric acid by
introducing a hot compressed air jet into the gases before they pass into the
condensers. Weak sulphuric acid of sp. gr. 1.6 collects in a saucer in which
the tower stands, and is then passed through a cooling worm. The weak
sulphuric acid, now entirely free from nitric and nitrous acids, may be
concentrated to sp. gr. 1.842 and 96 per cent. H_{2}SO_{4} by any of the
well-known processes, e.g., Kessler, Webb, Benker, Delplace, &c., and it
may be used again in the manufacture of nitro-glycerine or gun-cotton.
Two points in the manufacture of nitro-glycerine are of the greatest
importance, viz., the purity of the glycerine used, and the strength and
purity of the acids used in the nitration. With regard to the first of these,
great care should be taken, and a complete analysis and thorough
Page 56
examination, including a preliminary experimental nitration, should always
be instituted. As regards the second, the sulphuric acid should not only be
strong (96 per cent.), but as free from impurities as possible. With the nitric
acid, which is generally made at the explosive works where it is used, care
must be taken that it is as strong as possible (97 per cent. and upwards).
This can easily be obtained if the plant designed by Mr Oscar Guttmann[A]
is used. Having worked Mr Guttmann's plant for some time, I can testify as
to its value and efficiency.
[Footnote A: "The Manufacture of Nitric Acid," Jour. Soc. Chem. Ind.,
March 1893.]
Another form of nitric acid plant, which promises to be of considerable
service to the manufacturer of nitric acid for the purpose of nitrating, is the
invention of the late Mr Manning Prentice, of Stowmarket. Through the
kindness of Mr Prentice, I visited his works to see the plant in operation. It
consists of a still, divided into compartments or chambers in such a manner
that the fluid may pass continuously from one to the other. The nitric acid
being continuously separated by distillation, the contents of each division
vary—the first containing the full proportion of nitric acid, and each
succeeding one less of the nitric acid, until from the overflow of the last one
the bisulphate of soda flows away without any nitric acid. The nitrate of
soda is placed in weighed quantities in the hopper, whence it passes to the
feeder. The feeder is a miniature horizontal pug-mill, which receives the
streams of sulphuric acid and of nitrate, and after thoroughly mixing them,
delivers them into the still, where, under the influence of heat, they rapidly
become a homogeneous liquid, from which nitric acid continuously distils.
Mr Prentice says: "I may point out that while the ordinary process of
making nitric acid is one of fractional distillation by time, mine is fractional
distillation by space." "Instead of the operation being always at the same
be instituted. As regards the second, the sulphuric acid should not only be
strong (96 per cent.), but as free from impurities as possible. With the nitric
acid, which is generally made at the explosive works where it is used, care
must be taken that it is as strong as possible (97 per cent. and upwards).
This can easily be obtained if the plant designed by Mr Oscar Guttmann[A]
is used. Having worked Mr Guttmann's plant for some time, I can testify as
to its value and efficiency.
[Footnote A: "The Manufacture of Nitric Acid," Jour. Soc. Chem. Ind.,
March 1893.]
Another form of nitric acid plant, which promises to be of considerable
service to the manufacturer of nitric acid for the purpose of nitrating, is the
invention of the late Mr Manning Prentice, of Stowmarket. Through the
kindness of Mr Prentice, I visited his works to see the plant in operation. It
consists of a still, divided into compartments or chambers in such a manner
that the fluid may pass continuously from one to the other. The nitric acid
being continuously separated by distillation, the contents of each division
vary—the first containing the full proportion of nitric acid, and each
succeeding one less of the nitric acid, until from the overflow of the last one
the bisulphate of soda flows away without any nitric acid. The nitrate of
soda is placed in weighed quantities in the hopper, whence it passes to the
feeder. The feeder is a miniature horizontal pug-mill, which receives the
streams of sulphuric acid and of nitrate, and after thoroughly mixing them,
delivers them into the still, where, under the influence of heat, they rapidly
become a homogeneous liquid, from which nitric acid continuously distils.
Mr Prentice says: "I may point out that while the ordinary process of
making nitric acid is one of fractional distillation by time, mine is fractional
distillation by space." "Instead of the operation being always at the same
Page 57
point of space, but differing by the successive points of time, I arrange for
the differences to take place at different points of space, and these
differences exist at one and the same points of time." It is possible with this
plant to produce the full product of nitric acid of a gravity of 1.500, or to
obtain the acid of varying strengths from the different still-heads. One of
these stills, capable of producing about 4 tons of nitric acid per week,
weighs less than 2 tons. It is claimed that there is by their use a saving of
more than two-thirds in fuel, and four- fifths in condensing plant. Further
particulars and illustrations will be found in Mr Prentice's paper (Journal of
the Society of Chemical Industry, 1894, p. 323).
the differences to take place at different points of space, and these
differences exist at one and the same points of time." It is possible with this
plant to produce the full product of nitric acid of a gravity of 1.500, or to
obtain the acid of varying strengths from the different still-heads. One of
these stills, capable of producing about 4 tons of nitric acid per week,
weighs less than 2 tons. It is claimed that there is by their use a saving of
more than two-thirds in fuel, and four- fifths in condensing plant. Further
particulars and illustrations will be found in Mr Prentice's paper (Journal of
the Society of Chemical Industry, 1894, p. 323).
Page 58
CHAPTER III.
NITRO-CELLULOSE, &c.
Cellulose Properties—Discovery of Gun-Cotton—Properties of Gun-
Cotton—
Varieties of Soluble and Insoluble Gun-Cottons—Manufacture of Gun-
Cotton—
Dipping and Steeping—Whirling out the Acid—Washing—Boiling—
Pulping—
Compressing—The Waltham Abbey Process—Le Bouchet Process—
Granulation of
Gun-Cotton—Collodion-Cotton—Manufacture—Acid Mixture used—
Cotton used,
&c.—Nitrated Gun-Cotton—Tonite—Dangers in Manufacture of Gun-
Cotton—
Trench's Fire-Extinguishing Compound—Uses of Collodion-Cotton—
Celluloid—
Manufacture, &c.—Nitro-Starch, Nitro-Jute, and Nitro-Mannite.
~The Nitro-Celluloses.~—The substance known as cellulose forms the
groundwork of vegetable tissues. The cellulose of the woody parts of plants
was at one time supposed to be a distinct body, and was called lignine, but
they are now regarded as identical. The formula of cellulose is
NITRO-CELLULOSE, &c.
Cellulose Properties—Discovery of Gun-Cotton—Properties of Gun-
Cotton—
Varieties of Soluble and Insoluble Gun-Cottons—Manufacture of Gun-
Cotton—
Dipping and Steeping—Whirling out the Acid—Washing—Boiling—
Pulping—
Compressing—The Waltham Abbey Process—Le Bouchet Process—
Granulation of
Gun-Cotton—Collodion-Cotton—Manufacture—Acid Mixture used—
Cotton used,
&c.—Nitrated Gun-Cotton—Tonite—Dangers in Manufacture of Gun-
Cotton—
Trench's Fire-Extinguishing Compound—Uses of Collodion-Cotton—
Celluloid—
Manufacture, &c.—Nitro-Starch, Nitro-Jute, and Nitro-Mannite.
~The Nitro-Celluloses.~—The substance known as cellulose forms the
groundwork of vegetable tissues. The cellulose of the woody parts of plants
was at one time supposed to be a distinct body, and was called lignine, but
they are now regarded as identical. The formula of cellulose is
Page 59
(C_{6}H_{10}O_{6}){X}, and it is generally assumed that the molecular
formula must be represented by a multiple of the empirical formula,
C{12}H_{20}O_{10} being often regarded as the minimum. The
assumption is based on the existence of a penta-nitrate and the insoluble
and colloidal nature of cellulose. Green (Zeit. Farb. Text. Ind., 1904, 3, 97)
considers these reasons insufficient, and prefers to employ the single
formula C_{6}H_{10}O_{5}. Cellulose can be extracted in the pure state,
from young and tender portions of plants by first crushing them, to rupture
the cells, and then extracting with dilute hydrochloric acid, water, alcohol,
and ether in succession, until none of these solvents remove anything more.
Fine paper or cotton wool yield very nearly pure cellulose by similar
treatment.
Cellulose is a colourless, transparent mass, absolutely insoluble in water,
alcohol, or ether. It is, however, soluble in a solution of cuprammoniac
solution, prepared from basic carbonate or hydrate of copper and aqueous
ammonia. The specific gravity of cellulose is 1.25 to 1.45. According to
Schulze, its elementary composition is expressed by the percentage
numbers:—
Carbon 44.0 per cent. 44.2 per cent.
Hydrogen 6.3 " 6.4 "
Oxygen 49.7 " 49.4 "
These numbers represent the composition of the ash free cellulose.
Nearly all forms of cellulose, however, contain a small proportion of
mineral matters, and the union of these with the organic portion of the fibre
or tissue is of such a nature that the ash left on ignition preserves the form
of the original. "It is only in the growing point of certain young shoots that
the cellulose tissue is free from mineral constituents" (Hofmeister).
formula must be represented by a multiple of the empirical formula,
C{12}H_{20}O_{10} being often regarded as the minimum. The
assumption is based on the existence of a penta-nitrate and the insoluble
and colloidal nature of cellulose. Green (Zeit. Farb. Text. Ind., 1904, 3, 97)
considers these reasons insufficient, and prefers to employ the single
formula C_{6}H_{10}O_{5}. Cellulose can be extracted in the pure state,
from young and tender portions of plants by first crushing them, to rupture
the cells, and then extracting with dilute hydrochloric acid, water, alcohol,
and ether in succession, until none of these solvents remove anything more.
Fine paper or cotton wool yield very nearly pure cellulose by similar
treatment.
Cellulose is a colourless, transparent mass, absolutely insoluble in water,
alcohol, or ether. It is, however, soluble in a solution of cuprammoniac
solution, prepared from basic carbonate or hydrate of copper and aqueous
ammonia. The specific gravity of cellulose is 1.25 to 1.45. According to
Schulze, its elementary composition is expressed by the percentage
numbers:—
Carbon 44.0 per cent. 44.2 per cent.
Hydrogen 6.3 " 6.4 "
Oxygen 49.7 " 49.4 "
These numbers represent the composition of the ash free cellulose.
Nearly all forms of cellulose, however, contain a small proportion of
mineral matters, and the union of these with the organic portion of the fibre
or tissue is of such a nature that the ash left on ignition preserves the form
of the original. "It is only in the growing point of certain young shoots that
the cellulose tissue is free from mineral constituents" (Hofmeister).
Page 60
Cellulose is a very inert body. Cold concentrated sulphuric acid causes it
to swell up, and finally dissolves it, forming a viscous solution.
Hydrochloric acid has little or no action, but nitric acid has, and forms a
series of bodies known as nitrates or nitro-celluloses. Cellulose has some of
the properties of alcohols, among them the power of forming ethereal salts
with acids. When cellulose in any form, such as cotton, is brought into
contact with strong nitric acid at a low temperature, a nitrate or nitro
product, containing nitryl, or the NO_{2} group, is produced. The more or
less complete replacement of the hydroxylic hydrogen by NO_{2} groups
depends partly on the concentration of the nitric acid used, partly on the
duration of the action. If the most concentrated nitric and sulphuric acids
are employed, and the action allowed to proceed for some considerable
time, the highest nitrate, known as hexa-nitro- cellulose or gun-cotton,
C_{12}H_{14}O_{4}(O.NO_{2})_{6}, will be formed; but with weaker
acids, and a shorter exposure to their action, the tetra and penta and lower
nitrates will be formed.[A]
[Footnote A: The paper by Prof. Lunge, Jour. Amer. Chem. Soc., 1901,
23[8], 527-579, contains valuable information on this subject.]
Besides the nitrate, A. Luck[A] has proposed to use other esters of
cellulose, such as the acetate, benzoate, or butyrate. It is found that
cellulose acetate forms with nitro-glycerine a gelatinous body without
requiring the addition of a solvent. A sporting powder is proposed
composed of 75 parts of cellulose nitrate (13 per cent. N.) mixed with 13
parts of cellulose acetate.
[Footnote A: Eng. Pat. 24,662, 22nd November 1898.]
The discovery of gun-cotton is generally attributed to Schönbein (1846),
but Braconnot (in 1832) had previously nitrated starch, and six years later
Pelouse prepared nitro-cotton and various other nitro bodies, and Dumas
to swell up, and finally dissolves it, forming a viscous solution.
Hydrochloric acid has little or no action, but nitric acid has, and forms a
series of bodies known as nitrates or nitro-celluloses. Cellulose has some of
the properties of alcohols, among them the power of forming ethereal salts
with acids. When cellulose in any form, such as cotton, is brought into
contact with strong nitric acid at a low temperature, a nitrate or nitro
product, containing nitryl, or the NO_{2} group, is produced. The more or
less complete replacement of the hydroxylic hydrogen by NO_{2} groups
depends partly on the concentration of the nitric acid used, partly on the
duration of the action. If the most concentrated nitric and sulphuric acids
are employed, and the action allowed to proceed for some considerable
time, the highest nitrate, known as hexa-nitro- cellulose or gun-cotton,
C_{12}H_{14}O_{4}(O.NO_{2})_{6}, will be formed; but with weaker
acids, and a shorter exposure to their action, the tetra and penta and lower
nitrates will be formed.[A]
[Footnote A: The paper by Prof. Lunge, Jour. Amer. Chem. Soc., 1901,
23[8], 527-579, contains valuable information on this subject.]
Besides the nitrate, A. Luck[A] has proposed to use other esters of
cellulose, such as the acetate, benzoate, or butyrate. It is found that
cellulose acetate forms with nitro-glycerine a gelatinous body without
requiring the addition of a solvent. A sporting powder is proposed
composed of 75 parts of cellulose nitrate (13 per cent. N.) mixed with 13
parts of cellulose acetate.
[Footnote A: Eng. Pat. 24,662, 22nd November 1898.]
The discovery of gun-cotton is generally attributed to Schönbein (1846),
but Braconnot (in 1832) had previously nitrated starch, and six years later
Pelouse prepared nitro-cotton and various other nitro bodies, and Dumas
Page 61
nitrated paper, but Schönbein was apparently the first chemist to use a
mixture of strong nitric and sulphuric acids. Many chemists, such as Piobert
in France, Morin in Russia, and Abel in England, studied the subject; but it
was in Austria, under the auspices of Baron Von Lenk, that the greatest
progress was made. Lenk used cotton in the form of yarn, made up into
hanks, which he first washed in a solution of potash, and then with water,
and after drying dipped them in the acids. The acid mixture used consisted
of 3 parts by weight of sulphuric to 1 part of nitric acid, and were prepared
some time before use. The cotton was dipped one skein at a time, stirred for
a few minutes, pressed out, steeped, and excess of acid removed by washing
with water, then with dilute potash, and finally with water. Von Lenk's
process was used in England at Faversham (Messrs Hall's Works), but was
given up on account of an explosion (1847).
Sir Frederick Abel, working at Stowmarket and Waltham Abbey,
introduced several very important improvements into the process, the chief
among these being pulping. Having traced the cause of its instability to the
presence of substances caused by the action of the nitric acid on the
resinous or fatty substances contained in the cotton fibre, he succeeded in
eliminating them, by boiling the nitro-cotton in water, and by a thorough
washing, after pulping the cotton in poachers.
Although gun-cottons are generally spoken of as nitro-celluloses, they
are more correctly described as cellulose nitrates, for unlike nitro bodies of
other series, they do not yield, or have not yet done so, amido bodies, on
reduction with nascent hydrogen.[A] The equation of the formation of gun-
cotton is as follows:—
2(C_{6}H_{10}O_{5}) + 6HNO_{3} = C_{12}H_{14}O_{4}(NO_{3})
{6} + 6OH{2}. Cellulose. Nitric Acid. Gun-Cotton. Water.
mixture of strong nitric and sulphuric acids. Many chemists, such as Piobert
in France, Morin in Russia, and Abel in England, studied the subject; but it
was in Austria, under the auspices of Baron Von Lenk, that the greatest
progress was made. Lenk used cotton in the form of yarn, made up into
hanks, which he first washed in a solution of potash, and then with water,
and after drying dipped them in the acids. The acid mixture used consisted
of 3 parts by weight of sulphuric to 1 part of nitric acid, and were prepared
some time before use. The cotton was dipped one skein at a time, stirred for
a few minutes, pressed out, steeped, and excess of acid removed by washing
with water, then with dilute potash, and finally with water. Von Lenk's
process was used in England at Faversham (Messrs Hall's Works), but was
given up on account of an explosion (1847).
Sir Frederick Abel, working at Stowmarket and Waltham Abbey,
introduced several very important improvements into the process, the chief
among these being pulping. Having traced the cause of its instability to the
presence of substances caused by the action of the nitric acid on the
resinous or fatty substances contained in the cotton fibre, he succeeded in
eliminating them, by boiling the nitro-cotton in water, and by a thorough
washing, after pulping the cotton in poachers.
Although gun-cottons are generally spoken of as nitro-celluloses, they
are more correctly described as cellulose nitrates, for unlike nitro bodies of
other series, they do not yield, or have not yet done so, amido bodies, on
reduction with nascent hydrogen.[A] The equation of the formation of gun-
cotton is as follows:—
2(C_{6}H_{10}O_{5}) + 6HNO_{3} = C_{12}H_{14}O_{4}(NO_{3})
{6} + 6OH{2}. Cellulose. Nitric Acid. Gun-Cotton. Water.
Page 62
The sulphuric acid used does not take part in the reaction, but its
presence is absolutely essential to combine with the water set free, and thus
to prevent the weakening of the nitric acid. The acid mixture used at
Waltham Abbey consists of 3 parts by weight of sulphuric acid of 1.84
specific gravity, and 1 part of nitric acid of 1.52 specific gravity. The same
mixture is also used at Stowmarket (the New Explosive Company's Works).
The use of weaker acids results in the formation of collodion- cotton and
the lower nitrates generally.
[Footnote A: "Cellulose," by Cross and Bevan, ed. by W.R. Hodgkinson,
p. 9.]
The nitrate which goes under the name of gun-cotton is generally
supposed to be the hexa-nitrate, and to contain 14.14 per cent. of nitrogen;
but a higher percentage than 13.7 has not been obtained from any sample. It
is almost impossible (at any rate upon the manufacturing scale) to make
pure hexa-nitro-cellulose or gun-cotton; it is certain to contain several per
cents. of the soluble forms, i.e., lower nitrates. It often contains as much as
15 or 16 per cent., and only from 13.07[A] to 13.6 per cent. of nitrogen.
[Footnote A: Mr J.J. Sayers, in evidence before the court in the "Cordite
Case," says he found 15.2 and 16.1 per cent. soluble cotton, and 13.07 and
13.08 per cent. nitrogen in two samples of Waltham Abbey gun-cotton.]
A whole series of nitrates of cellulose are supposed to exist, the highest
member being the hexa-nitrate, and the lowest the mono-nitrate. Gun-cotton
was at one time regarded as the tri-nitrate, and collodion-cotton as the di-
nitrate and mono-nitrate, their respective formula being given as follows:—
Mono-nitro-cellulose C_{6}H_{9}(NO_{2})O_{5} = 6.763 per cent.
nitrogen.
presence is absolutely essential to combine with the water set free, and thus
to prevent the weakening of the nitric acid. The acid mixture used at
Waltham Abbey consists of 3 parts by weight of sulphuric acid of 1.84
specific gravity, and 1 part of nitric acid of 1.52 specific gravity. The same
mixture is also used at Stowmarket (the New Explosive Company's Works).
The use of weaker acids results in the formation of collodion- cotton and
the lower nitrates generally.
[Footnote A: "Cellulose," by Cross and Bevan, ed. by W.R. Hodgkinson,
p. 9.]
The nitrate which goes under the name of gun-cotton is generally
supposed to be the hexa-nitrate, and to contain 14.14 per cent. of nitrogen;
but a higher percentage than 13.7 has not been obtained from any sample. It
is almost impossible (at any rate upon the manufacturing scale) to make
pure hexa-nitro-cellulose or gun-cotton; it is certain to contain several per
cents. of the soluble forms, i.e., lower nitrates. It often contains as much as
15 or 16 per cent., and only from 13.07[A] to 13.6 per cent. of nitrogen.
[Footnote A: Mr J.J. Sayers, in evidence before the court in the "Cordite
Case," says he found 15.2 and 16.1 per cent. soluble cotton, and 13.07 and
13.08 per cent. nitrogen in two samples of Waltham Abbey gun-cotton.]
A whole series of nitrates of cellulose are supposed to exist, the highest
member being the hexa-nitrate, and the lowest the mono-nitrate. Gun-cotton
was at one time regarded as the tri-nitrate, and collodion-cotton as the di-
nitrate and mono-nitrate, their respective formula being given as follows:—
Mono-nitro-cellulose C_{6}H_{9}(NO_{2})O_{5} = 6.763 per cent.
nitrogen.
Page 63
Di-nitro-cellulose C_{6}H_{8}(NO_{2}){2}O{5} = 11.11 " "
Tri-nitro-cellulose C_{6}H_{7}(NO_{2}){3}O{5} = 14.14 " "
But gun-cotton is now regarded as the hexa-nitrate, and collodion-cotton
as a mixture of all the other nitrates. In fact, chemists are now more inclined
to divide nitro-cellulose into the soluble and insoluble forms, the reason
being that it is quite easy to make a nitro-cellulose entirely soluble in a
mixture of ether-alcohol, and yet containing as high a percentage of
nitrogen as 12.6; whereas the di-nitrate[A] should theoretically only contain
11.11 per cent. On the other hand, it is not possible to make gun-cotton with
a higher percentage of nitrogen than about 13.7, even when it does not
contain any nitro-cotton that is soluble in ether-alcohol.[B] The fact is that
it is not at present possible to make a nitro-cellulose which shall be either
entirely soluble or entirely insoluble, or which will contain the theoretical
content of nitrogen to suit any of the above formulæ for the cellulose
nitrates. Prof. G. Lunge gives the following list of nitration products of
cellulose:—
[Footnote A: The penta-nitrate C_{12}H_{15}O_{5}(NO_{3})_{5} =
12.75 per cent. nitrogen.]
[Footnote B: In the Cordite Trial (1894) Sir F.A. Abel said, "Before 1888
there was a broad distinction between soluble and insoluble nitro- cellulose,
collodion-cotton being soluble (in ether-alcohol) and gun-cotton insoluble."
Sir H.E. Roscoe, "That he had been unable to make a nitro-cotton with a
higher nitrogen content than 13.7." And Professor G. Lunge said, "Gun-
cotton always contained soluble cotton, and vice versa." These opinions
were also generally confirmed by Sir E. Frankland, Sir W. Crookes, Dr
Armstrong, and others.]
Dodeca-nitro-cellulose C_{24}H_{28}O_{20}(NO_{2}){12} = 14.16
per cent.
Tri-nitro-cellulose C_{6}H_{7}(NO_{2}){3}O{5} = 14.14 " "
But gun-cotton is now regarded as the hexa-nitrate, and collodion-cotton
as a mixture of all the other nitrates. In fact, chemists are now more inclined
to divide nitro-cellulose into the soluble and insoluble forms, the reason
being that it is quite easy to make a nitro-cellulose entirely soluble in a
mixture of ether-alcohol, and yet containing as high a percentage of
nitrogen as 12.6; whereas the di-nitrate[A] should theoretically only contain
11.11 per cent. On the other hand, it is not possible to make gun-cotton with
a higher percentage of nitrogen than about 13.7, even when it does not
contain any nitro-cotton that is soluble in ether-alcohol.[B] The fact is that
it is not at present possible to make a nitro-cellulose which shall be either
entirely soluble or entirely insoluble, or which will contain the theoretical
content of nitrogen to suit any of the above formulæ for the cellulose
nitrates. Prof. G. Lunge gives the following list of nitration products of
cellulose:—
[Footnote A: The penta-nitrate C_{12}H_{15}O_{5}(NO_{3})_{5} =
12.75 per cent. nitrogen.]
[Footnote B: In the Cordite Trial (1894) Sir F.A. Abel said, "Before 1888
there was a broad distinction between soluble and insoluble nitro- cellulose,
collodion-cotton being soluble (in ether-alcohol) and gun-cotton insoluble."
Sir H.E. Roscoe, "That he had been unable to make a nitro-cotton with a
higher nitrogen content than 13.7." And Professor G. Lunge said, "Gun-
cotton always contained soluble cotton, and vice versa." These opinions
were also generally confirmed by Sir E. Frankland, Sir W. Crookes, Dr
Armstrong, and others.]
Dodeca-nitro-cellulose C_{24}H_{28}O_{20}(NO_{2}){12} = 14.16
per cent.
Page 64
nitrogen. (= old tri-nitro-cellulose)
Endeca-nitro-cellulose C{24}H_{29}O_{20}(NO_{2}){11} = 13.50 per
cent.
nitrogen.
Deca-nitro-cellulose C{24}H_{30}O_{20}(NO_{2}){10} = 12.78 per cent.
nitrogen.
Ennea-nitro-cellulose C{24}H_{31}O_{20}(NO_{2}){9} = 11.98 per cent.
nitrogen.
Octo-nitro-cellulose C{24}H_{32}O_{20}(NO_{2}){8} = 11.13 per cent.
nitrogen. (= old di-nitro-cellulose)
Hepta-nitro-cellulose C{24}H_{33}O_{20}(NO_{2}){7} = 10.19 per cent.
nitrogen.
Hexa-nitro-cellulose C{24}H_{34}O_{20}(NO_{2}){6} = 9.17 per cent.
nitrogen.
Penta-nitro-cellulose C{24}H_{35}O_{20}(NO_{2}){5} = 8.04 per cent.
nitrogen.
Tetra-nitro-cellulose C{24}H_{36}O_{20}(NO_{2})_{4} = 6.77 per cent.
nitrogen. (= old mono-nitro-cellulose)
It is not unlikely that a long series of nitrates exists. It is at any rate
certain that whatever strength of acids may be used, and whatever
temperature or other conditions may be present during the nitration, that the
product formed always consists of a mixture of the soluble and insoluble
nitro-cellulose.
Theoretically 100 parts of cotton by weight should produce 218.4 parts of
gun-cotton, but in practice the yield is a good deal less, both in the case of
gun-cotton or collodion-cotton. In speaking of soluble and insoluble nitro-
cellulose, it is their behaviour, when treated with a solution consisting of 2
parts ether and 1 of alcohol, that is referred to. There is, however, another
very important difference, and that is their different solubility in nitro-
Endeca-nitro-cellulose C{24}H_{29}O_{20}(NO_{2}){11} = 13.50 per
cent.
nitrogen.
Deca-nitro-cellulose C{24}H_{30}O_{20}(NO_{2}){10} = 12.78 per cent.
nitrogen.
Ennea-nitro-cellulose C{24}H_{31}O_{20}(NO_{2}){9} = 11.98 per cent.
nitrogen.
Octo-nitro-cellulose C{24}H_{32}O_{20}(NO_{2}){8} = 11.13 per cent.
nitrogen. (= old di-nitro-cellulose)
Hepta-nitro-cellulose C{24}H_{33}O_{20}(NO_{2}){7} = 10.19 per cent.
nitrogen.
Hexa-nitro-cellulose C{24}H_{34}O_{20}(NO_{2}){6} = 9.17 per cent.
nitrogen.
Penta-nitro-cellulose C{24}H_{35}O_{20}(NO_{2}){5} = 8.04 per cent.
nitrogen.
Tetra-nitro-cellulose C{24}H_{36}O_{20}(NO_{2})_{4} = 6.77 per cent.
nitrogen. (= old mono-nitro-cellulose)
It is not unlikely that a long series of nitrates exists. It is at any rate
certain that whatever strength of acids may be used, and whatever
temperature or other conditions may be present during the nitration, that the
product formed always consists of a mixture of the soluble and insoluble
nitro-cellulose.
Theoretically 100 parts of cotton by weight should produce 218.4 parts of
gun-cotton, but in practice the yield is a good deal less, both in the case of
gun-cotton or collodion-cotton. In speaking of soluble and insoluble nitro-
cellulose, it is their behaviour, when treated with a solution consisting of 2
parts ether and 1 of alcohol, that is referred to. There is, however, another
very important difference, and that is their different solubility in nitro-
Page 65
glycerine. The lower nitrates or soluble form is soluble in nitro-glycerine
under the influence of heat, a temperature of about 50° C. being required.
At lower temperatures the dissolution is very imperfect indeed; and after the
materials have been left in contact for days, the threads of the cotton can
still be distinguished. The insoluble form or gun-cotton is entirely insoluble
in nitro-glycerine. It can, however, be made to dissolve[A] by the aid of
acetone or acetic ether. Both or rather all the forms of nitro-cellulose can be
dissolved in acetone or acetic ether. They also dissolve in concentrated
sulphuric acid, and the penta-nitrate in nitric acid at about 80° or 90° C.
[Footnote A: Or rather to form a transparent jelly.]
The penta-nitrate may be obtained in a pure state by the following
process, devised by Eder:—The gun-cotton is dissolved in concentrated
nitric acid at 90° C., and reprecipitated by the addition of concentrated
sulphuric acid. After cooling to 0° C., and mixing with a larger volume of
water, the precipitated nitrate is washed with water, then with alcohol,
dissolved in ether-alcohol, and again precipitated with water, when it is
obtained pure. This nitrate is soluble in ether-alcohol, and slightly in acetic
acid, easily in acetone, acetic ether, and methyl-alcohol, insoluble in
alcohol. Strong potash (KOH) solution converts into the di-nitrate
C_{12}H_{18}O_{8}(NO_{3})_{2}. The hexa-nitrate is not soluble in
acetic acid or methyl-alcohol.
The lower nitrates known as the tetra- and tri-nitrates are formed together
when cellulose is treated with a mixture of weak acids, and allowed to
remain in contact with them for a very short time (twenty minutes). They
cannot be separated from one another, as they all dissolve equally in ether-
alcohol, acetic ether, acetic acid, methyl-alcohol, acetone, amyl acetate, &c.
As far as the manufacture of explosive bodies is concerned, the two
forms of nitro-cellulose used and manufactured are gun-cotton or the hexa-
under the influence of heat, a temperature of about 50° C. being required.
At lower temperatures the dissolution is very imperfect indeed; and after the
materials have been left in contact for days, the threads of the cotton can
still be distinguished. The insoluble form or gun-cotton is entirely insoluble
in nitro-glycerine. It can, however, be made to dissolve[A] by the aid of
acetone or acetic ether. Both or rather all the forms of nitro-cellulose can be
dissolved in acetone or acetic ether. They also dissolve in concentrated
sulphuric acid, and the penta-nitrate in nitric acid at about 80° or 90° C.
[Footnote A: Or rather to form a transparent jelly.]
The penta-nitrate may be obtained in a pure state by the following
process, devised by Eder:—The gun-cotton is dissolved in concentrated
nitric acid at 90° C., and reprecipitated by the addition of concentrated
sulphuric acid. After cooling to 0° C., and mixing with a larger volume of
water, the precipitated nitrate is washed with water, then with alcohol,
dissolved in ether-alcohol, and again precipitated with water, when it is
obtained pure. This nitrate is soluble in ether-alcohol, and slightly in acetic
acid, easily in acetone, acetic ether, and methyl-alcohol, insoluble in
alcohol. Strong potash (KOH) solution converts into the di-nitrate
C_{12}H_{18}O_{8}(NO_{3})_{2}. The hexa-nitrate is not soluble in
acetic acid or methyl-alcohol.
The lower nitrates known as the tetra- and tri-nitrates are formed together
when cellulose is treated with a mixture of weak acids, and allowed to
remain in contact with them for a very short time (twenty minutes). They
cannot be separated from one another, as they all dissolve equally in ether-
alcohol, acetic ether, acetic acid, methyl-alcohol, acetone, amyl acetate, &c.
As far as the manufacture of explosive bodies is concerned, the two
forms of nitro-cellulose used and manufactured are gun-cotton or the hexa-
Page 66
nitrate (once regarded as tri-nitro-cellulose), which is also known as
insoluble gun-cotton, and the soluble form of gun-cotton, which is also
known as collodion, and consists of a mixture of several of the lower
nitrates. It is probable that it chiefly consists, however, of the next highest
nitrate to gun-cotton, as the theoretical percentage of nitrogen for this body,.
the penta-nitrate, is 12.75 per cent., and analyses of commercial collodion-
cotton, entirely soluble in ether-alcohol, often give as high a percentage as
12.6.
We shall only describe the manufacture of the two forms known as
soluble and insoluble, and shall refer to them under their better known
names of gun-cotton and collodion-cotton. The following would, however,
be the formulæ[A] and percentage of nitrogen of the complete series:—
Hexa-nitro-cellulose C_{12}H_{14}O_{4}(NO_{3}){6} 14.14 per cent.
nitrogen.
Penta-nitro-cellulose C{12}H_{15}O_{5}(NO_{3}){5} 12.75 per cent.
nitrogen.
Tetra-nitro-cellulose C{12}H_{16}O_{6}(NO_{3}){4} 11.11 per cent.
nitrogen.
Tri-nitro-cellulose C{12}H_{17}O_{7}(NO_{3}){3} 9.13 per cent.
nitrogen.
Di-nitro-cellulose C{12}H_{18}O_{8}(NO_{3}){2} 7.65 per cent.
nitrogen.
Mono-nitrocellulose C{12}H_{19}O_{9}(NO_{3}) 3.80 per cent.
nitrogen.
[Footnote A: Berthelot takes C_{24}H_{40}O_{20} as the formula of
cellulose; and M. Vieille regards the highest nitrate as (C_{24}H_{18}
(NO_{3}H){11}O{9}). Compt. Rend., 1882, p. 132.]
insoluble gun-cotton, and the soluble form of gun-cotton, which is also
known as collodion, and consists of a mixture of several of the lower
nitrates. It is probable that it chiefly consists, however, of the next highest
nitrate to gun-cotton, as the theoretical percentage of nitrogen for this body,.
the penta-nitrate, is 12.75 per cent., and analyses of commercial collodion-
cotton, entirely soluble in ether-alcohol, often give as high a percentage as
12.6.
We shall only describe the manufacture of the two forms known as
soluble and insoluble, and shall refer to them under their better known
names of gun-cotton and collodion-cotton. The following would, however,
be the formulæ[A] and percentage of nitrogen of the complete series:—
Hexa-nitro-cellulose C_{12}H_{14}O_{4}(NO_{3}){6} 14.14 per cent.
nitrogen.
Penta-nitro-cellulose C{12}H_{15}O_{5}(NO_{3}){5} 12.75 per cent.
nitrogen.
Tetra-nitro-cellulose C{12}H_{16}O_{6}(NO_{3}){4} 11.11 per cent.
nitrogen.
Tri-nitro-cellulose C{12}H_{17}O_{7}(NO_{3}){3} 9.13 per cent.
nitrogen.
Di-nitro-cellulose C{12}H_{18}O_{8}(NO_{3}){2} 7.65 per cent.
nitrogen.
Mono-nitrocellulose C{12}H_{19}O_{9}(NO_{3}) 3.80 per cent.
nitrogen.
[Footnote A: Berthelot takes C_{24}H_{40}O_{20} as the formula of
cellulose; and M. Vieille regards the highest nitrate as (C_{24}H_{18}
(NO_{3}H){11}O{9}). Compt. Rend., 1882, p. 132.]
Page 67
~Properties of Gun-Cotton.~—The absolute density of gun-cotton is 1.5.
When in lumps its apparent density is 0.1; if twisted into thread, 0.25; when
subjected, in the form of pulp, to hydraulic pressure, 1.0 to 1.4. Gun-cotton
preserves the appearance of the cotton from which it is made. It is, however,
harsher to the touch; it is only slightly hygroscopic (dry gun-cotton absorbs
2 per cent. of moisture from the air). It possesses the property of becoming
electrified by friction. It is soluble in acetic ether, amyl acetate, and acetone,
insoluble in water, alcohol, ether, ether-alcohol, methyl-alcohol, &c. It is
very explosive, and is ignited by contact with an ignited body, or by shock,
or when it is raised to a temperature of 172° C. It burns with a yellowish
flame, almost without smoke, and leaves little or no residue. The volume of
the gases formed is large, and consists of carbonic acid, carbonic oxide,
nitrogen, and water gas. Compressed gun-cotton when ignited often
explodes when previously heated to 100° C.
Gun-cotton kept at 80° to 100° C. decomposes slowly, and sunlight
causes it to undergo a slow decomposition. It can, however, be preserved
for years without undergoing any alteration. It is very susceptible to
explosions by influence. For instance, a torpedo, even placed at a long
distance, may explode a line of torpedoes charged with gun-cotton. The
velocity of the propagation of the explosion in metallic tubes filled with
pulverised gun-cotton has been found to be from 5,000 to 6,000 mms. per
second in tin tubes, and 4,000 in leaden tubes (Sebert).
Gun-cotton loosely exposed in the open air burns eight times as quickly
as powder (Piobert). A thin disc of gun-cotton may be fired into from a rifle
without explosion; but if the thickness of the disc be increased, an explosion
may occur. The effect of gun-cotton in mines is very nearly the same as that
of dynamite for equal weights. It requires, however, a stronger detonator,
and it gives rise to a larger quantity of carbonic oxide gas. Gun-cotton
should be neutral to litmus, and should stand the Government heat test—
When in lumps its apparent density is 0.1; if twisted into thread, 0.25; when
subjected, in the form of pulp, to hydraulic pressure, 1.0 to 1.4. Gun-cotton
preserves the appearance of the cotton from which it is made. It is, however,
harsher to the touch; it is only slightly hygroscopic (dry gun-cotton absorbs
2 per cent. of moisture from the air). It possesses the property of becoming
electrified by friction. It is soluble in acetic ether, amyl acetate, and acetone,
insoluble in water, alcohol, ether, ether-alcohol, methyl-alcohol, &c. It is
very explosive, and is ignited by contact with an ignited body, or by shock,
or when it is raised to a temperature of 172° C. It burns with a yellowish
flame, almost without smoke, and leaves little or no residue. The volume of
the gases formed is large, and consists of carbonic acid, carbonic oxide,
nitrogen, and water gas. Compressed gun-cotton when ignited often
explodes when previously heated to 100° C.
Gun-cotton kept at 80° to 100° C. decomposes slowly, and sunlight
causes it to undergo a slow decomposition. It can, however, be preserved
for years without undergoing any alteration. It is very susceptible to
explosions by influence. For instance, a torpedo, even placed at a long
distance, may explode a line of torpedoes charged with gun-cotton. The
velocity of the propagation of the explosion in metallic tubes filled with
pulverised gun-cotton has been found to be from 5,000 to 6,000 mms. per
second in tin tubes, and 4,000 in leaden tubes (Sebert).
Gun-cotton loosely exposed in the open air burns eight times as quickly
as powder (Piobert). A thin disc of gun-cotton may be fired into from a rifle
without explosion; but if the thickness of the disc be increased, an explosion
may occur. The effect of gun-cotton in mines is very nearly the same as that
of dynamite for equal weights. It requires, however, a stronger detonator,
and it gives rise to a larger quantity of carbonic oxide gas. Gun-cotton
should be neutral to litmus, and should stand the Government heat test—
Page 68
temperature of 150° F. for fifteen minutes (see page 249). In the French
Navy gun-cotton is submitted to a heat test of 65° C. (= 149° F.) for eleven
minutes. It should contain as small a percentage of soluble nitro-cotton and
of non-nitrated cotton as possible.
The products of perfectly detonated gun-cotton may be expressed by the
following equation:—
2C_{12}H_{14}O_{4}(NO_{3}){6} = 18CO + 6CO{2} + 14H_{2}O + 12N.
It does not therefore contain sufficient oxygen for the complete
combustion of its carbon. It is for this reason that when used for mining
purposes a nitrate is generally added to supply this defect (as, for instance,
in tonite). It tends also to prevent the evolution of the poisonous gas,
carbonic oxide. The success of the various gelatine explosives is due to this
fact, viz., that the nitro-glycerine has an excess of oxygen, and the nitro-
cotton too little, and thus the two explosives help one another.
In practice the gases resulting from the explosion of gun-cotton are—
Carbonic oxide, 28.55; carbonic acid, 19.11; marsh gas (CH_{4}), 11.17;
nitric oxide, 8.83; nitrogen, 8.56; water vapour, 21.93 per cent. The late Mr
E.O. Brown, of Woolwich Arsenal, discovered that perfectly wet and
uninflammable compressed gun-cotton could be easily detonated by the
detonation of a priming charge of the dry material in contact with it. This
rendered the use of gun-cotton very much safer for use as a military or
mining explosive.
As a mining explosive, however, gun-cotton is now chiefly used under
the form of tonite, which is a mixture of half gun-cotton and half barium
nitrate. This material is sometimes spoken of as "nitrated gun-cotton." The
weight of gun-cotton required to produce an equal effect either in heavy
ordnance or in small arms is to the weight of gunpowder in the proportion
Navy gun-cotton is submitted to a heat test of 65° C. (= 149° F.) for eleven
minutes. It should contain as small a percentage of soluble nitro-cotton and
of non-nitrated cotton as possible.
The products of perfectly detonated gun-cotton may be expressed by the
following equation:—
2C_{12}H_{14}O_{4}(NO_{3}){6} = 18CO + 6CO{2} + 14H_{2}O + 12N.
It does not therefore contain sufficient oxygen for the complete
combustion of its carbon. It is for this reason that when used for mining
purposes a nitrate is generally added to supply this defect (as, for instance,
in tonite). It tends also to prevent the evolution of the poisonous gas,
carbonic oxide. The success of the various gelatine explosives is due to this
fact, viz., that the nitro-glycerine has an excess of oxygen, and the nitro-
cotton too little, and thus the two explosives help one another.
In practice the gases resulting from the explosion of gun-cotton are—
Carbonic oxide, 28.55; carbonic acid, 19.11; marsh gas (CH_{4}), 11.17;
nitric oxide, 8.83; nitrogen, 8.56; water vapour, 21.93 per cent. The late Mr
E.O. Brown, of Woolwich Arsenal, discovered that perfectly wet and
uninflammable compressed gun-cotton could be easily detonated by the
detonation of a priming charge of the dry material in contact with it. This
rendered the use of gun-cotton very much safer for use as a military or
mining explosive.
As a mining explosive, however, gun-cotton is now chiefly used under
the form of tonite, which is a mixture of half gun-cotton and half barium
nitrate. This material is sometimes spoken of as "nitrated gun-cotton." The
weight of gun-cotton required to produce an equal effect either in heavy
ordnance or in small arms is to the weight of gunpowder in the proportion
Page 69
of 1 to 3, i.e., an equal weight of gun-cotton would produce three times the
effect of gunpowder. Its rapidity of combustion, however, requires to be
modified for use in firearms. Hence the lower nitrates are generally used, or
such compounds as nitro-lignose, nitrated wood, &c., are used.
The initial pressure produced by the explosion of gun-cotton is very
large, equal to 18,135 atmospheres, and 8,740 kilogrammes per square
centimetre for 1 kilo., the heat liberated being 1,075 calories (water liquid),
or 997.7 cals. (water gaseous), but the quantity of heat liberated changes
with the equation of decomposition. According to Berthelot,[A] the heat of
formation of collodion-cotton is 696 cals. for 1,053 grms., or 661 cals. for 1
kilo. The heat liberated in the total combustion of gun-cotton by free
oxygen at constant pressure is 2,633 cals. for 1,143 grms., or for 1 kilo.
gun-cotton 2,302 cals. (water liquid), or 2,177 cals. (water gaseous). The
heat of decomposition of gun- cotton in a closed vessel, found by
experiment at a low density of charge (0.023), amounts to 1,071 cals. for 1
kilo. of the substance, dry and free from ash. To obtain the maximum effect
of gun-cotton it must be used in a compressed state, for the initial pressures
are thereby increased. Wet gun-cotton s much less sensitive to shock than
dry. Paraffin also reduces its liability to explode, so also does camphor.
[Footnote A: "Explosives and their Power," trans. by Hake and M'Nab.]
The substance known as celluloid, a variety of nitro-cellulose nearly
corresponding to the formula C_{24}H_{24}(NO_{3}H){8}O{12}, to
which camphor and various inert substances are added, so as to render it
non-sensitive to shock, may be worked with tools, and turned in the lathe in
the same manner as ivory, instead of which material celluloid is now largely
used for such articles as knife handles, combs, &c. Celluloid is very plastic
when heated towards 150° C., and tends to become very sensitive to shock,
and in large quantities might become explosive during a fire, owing to the
effect of gunpowder. Its rapidity of combustion, however, requires to be
modified for use in firearms. Hence the lower nitrates are generally used, or
such compounds as nitro-lignose, nitrated wood, &c., are used.
The initial pressure produced by the explosion of gun-cotton is very
large, equal to 18,135 atmospheres, and 8,740 kilogrammes per square
centimetre for 1 kilo., the heat liberated being 1,075 calories (water liquid),
or 997.7 cals. (water gaseous), but the quantity of heat liberated changes
with the equation of decomposition. According to Berthelot,[A] the heat of
formation of collodion-cotton is 696 cals. for 1,053 grms., or 661 cals. for 1
kilo. The heat liberated in the total combustion of gun-cotton by free
oxygen at constant pressure is 2,633 cals. for 1,143 grms., or for 1 kilo.
gun-cotton 2,302 cals. (water liquid), or 2,177 cals. (water gaseous). The
heat of decomposition of gun- cotton in a closed vessel, found by
experiment at a low density of charge (0.023), amounts to 1,071 cals. for 1
kilo. of the substance, dry and free from ash. To obtain the maximum effect
of gun-cotton it must be used in a compressed state, for the initial pressures
are thereby increased. Wet gun-cotton s much less sensitive to shock than
dry. Paraffin also reduces its liability to explode, so also does camphor.
[Footnote A: "Explosives and their Power," trans. by Hake and M'Nab.]
The substance known as celluloid, a variety of nitro-cellulose nearly
corresponding to the formula C_{24}H_{24}(NO_{3}H){8}O{12}, to
which camphor and various inert substances are added, so as to render it
non-sensitive to shock, may be worked with tools, and turned in the lathe in
the same manner as ivory, instead of which material celluloid is now largely
used for such articles as knife handles, combs, &c. Celluloid is very plastic
when heated towards 150° C., and tends to become very sensitive to shock,
and in large quantities might become explosive during a fire, owing to the
Page 70
general heating of the mass, and the consequent evaporation of the
camphor. When kept in the air bath at 135° C., celluloid decomposes
quickly. In an experiment (made by M. Berthelot) in a closed vessel at 135°
C., and the density of the charge being 0.4, it ended in exploding,
developing a pressure of 3,000 kilos. A large package of celluloid combs
also exploded in the guard's van on one of the German railways a few years
ago. Although it is not an explosive under ordinary circumstances, or even
with a powerful detonator, considerable care should be exercised in its
manufacture.
~The Manufacture of Gun-Cotton.~—The method used for the
manufacture of gun-cotton is that of Abel (Spec. No. 1102, 20. 4. 65). It was
worked out chiefly at Stowmarket[A] and Waltham Abbey,[B] but has in the
course of time undergone several alterations. These modifications have
taken place, however, chiefly upon the Continent, and relate more to the
apparatus and machinery used than to any alteration in the process itself.
The form of cellulose used is cotton-waste,[C] which consists of the
clippings and waste material from cotton mills. After it has been cleaned
and purified from grease, oil, and other fatty substances by treatment with
alkaline solutions, it is carefully picked over, and every piece of coloured
cotton rag or string carefully removed. The next operation to which it is
submitted has for its object the opening up of the material. For this purpose
it is put through a carding machine, and afterwards through a cutting
machine, whereby it is reduced to a state suitable for its subsequent
treatment with acids, that is, it has been cut into short lengths, and the fibres
opened up and separated from one another.
[Footnote A: The New Explosive Co. Works.]
[Footnote B: Royal Gunpowder Factory.]
camphor. When kept in the air bath at 135° C., celluloid decomposes
quickly. In an experiment (made by M. Berthelot) in a closed vessel at 135°
C., and the density of the charge being 0.4, it ended in exploding,
developing a pressure of 3,000 kilos. A large package of celluloid combs
also exploded in the guard's van on one of the German railways a few years
ago. Although it is not an explosive under ordinary circumstances, or even
with a powerful detonator, considerable care should be exercised in its
manufacture.
~The Manufacture of Gun-Cotton.~—The method used for the
manufacture of gun-cotton is that of Abel (Spec. No. 1102, 20. 4. 65). It was
worked out chiefly at Stowmarket[A] and Waltham Abbey,[B] but has in the
course of time undergone several alterations. These modifications have
taken place, however, chiefly upon the Continent, and relate more to the
apparatus and machinery used than to any alteration in the process itself.
The form of cellulose used is cotton-waste,[C] which consists of the
clippings and waste material from cotton mills. After it has been cleaned
and purified from grease, oil, and other fatty substances by treatment with
alkaline solutions, it is carefully picked over, and every piece of coloured
cotton rag or string carefully removed. The next operation to which it is
submitted has for its object the opening up of the material. For this purpose
it is put through a carding machine, and afterwards through a cutting
machine, whereby it is reduced to a state suitable for its subsequent
treatment with acids, that is, it has been cut into short lengths, and the fibres
opened up and separated from one another.
[Footnote A: The New Explosive Co. Works.]
[Footnote B: Royal Gunpowder Factory.]
Page 71
[Footnote C: Costs from £10 to £25 a ton. In his description of the
"Preparation of Cotton-waste for the Manufacture of Smokeless Powder,"
A. Hertzog states that the German military authorities require a cotton
which when thrown into water sinks in two minutes; when nitrated, does
not disintegrate; when treated with ether, yields only 0.9 per cent. of fat;
and containing only traces of chlorine, lime, magnesia, iron, sulphuric acid,
and phosphoric acid. If the cotton is very greasy, it must be first boiled with
soda-lye under pressure, washed, bleached with chlorine, washed, treated
with sulphuric acid or HCl, again washed, centrifugated, and dried; if very
greasy indeed a preliminary treatment with lime-water is desirable. See also
"Inspection of Cotton-Waste for Use in the Manufacture of Gun-cotton," by
C.E. Munro, Jour. Am. Chem. Soc., 1895, 17, 783.]
~Drying the Cotton.~—This operation is performed in either of two
ways. The cotton may either be placed upon shelves in a drying house,
through which a current of hot air circulates, or dried in steam-jacketed
cylinders. It is very essential that the cotton should be as dry as possible
before dipping in the acids, especially if a wholly "insoluble" nitro-cellulose
is to be obtained. After drying it should not contain more than 0.5 per cent.
of moisture, and less than this if possible. The more general method of
drying the cotton is in steam-jacketed tubes, i.e., double cylinders of iron,
some 5 feet long and 1-1/2 foot wide. The cotton is placed in the central
chamber (Fig. 10), while steam is made to circulate in the surrounding
jacket, and keeps the whole cylinder at a high temperature (steam pipes may
be coiled round the outside of an iron tube, and will answer equally well).
By means of a pipe which communicates with a compressed air reservoir, a
current of air enters at the bottom, and finds its way up through the cotton,
and helps to remove the moisture that it contains. The raw cotton generally
contains about 10 per cent. of moisture and should be dried until it contains
only 1/2 per cent. or less. For this it will generally have to remain in the
drying cylinder for about five hours. At the end of that time a sample should
"Preparation of Cotton-waste for the Manufacture of Smokeless Powder,"
A. Hertzog states that the German military authorities require a cotton
which when thrown into water sinks in two minutes; when nitrated, does
not disintegrate; when treated with ether, yields only 0.9 per cent. of fat;
and containing only traces of chlorine, lime, magnesia, iron, sulphuric acid,
and phosphoric acid. If the cotton is very greasy, it must be first boiled with
soda-lye under pressure, washed, bleached with chlorine, washed, treated
with sulphuric acid or HCl, again washed, centrifugated, and dried; if very
greasy indeed a preliminary treatment with lime-water is desirable. See also
"Inspection of Cotton-Waste for Use in the Manufacture of Gun-cotton," by
C.E. Munro, Jour. Am. Chem. Soc., 1895, 17, 783.]
~Drying the Cotton.~—This operation is performed in either of two
ways. The cotton may either be placed upon shelves in a drying house,
through which a current of hot air circulates, or dried in steam-jacketed
cylinders. It is very essential that the cotton should be as dry as possible
before dipping in the acids, especially if a wholly "insoluble" nitro-cellulose
is to be obtained. After drying it should not contain more than 0.5 per cent.
of moisture, and less than this if possible. The more general method of
drying the cotton is in steam-jacketed tubes, i.e., double cylinders of iron,
some 5 feet long and 1-1/2 foot wide. The cotton is placed in the central
chamber (Fig. 10), while steam is made to circulate in the surrounding
jacket, and keeps the whole cylinder at a high temperature (steam pipes may
be coiled round the outside of an iron tube, and will answer equally well).
By means of a pipe which communicates with a compressed air reservoir, a
current of air enters at the bottom, and finds its way up through the cotton,
and helps to remove the moisture that it contains. The raw cotton generally
contains about 10 per cent. of moisture and should be dried until it contains
only 1/2 per cent. or less. For this it will generally have to remain in the
drying cylinder for about five hours. At the end of that time a sample should
Page 72
be taken from the top of the cylinder, and dried in the water oven (100° C.
[A]) for an hour to an hour and a half, and re-weighed, and the moisture
then remaining in it calculated.
[Footnote A: It is dried at 180° C. at Waltham Abbey, in a specially
constructed drying chamber.]
[Illustration: FIG. 10.—COTTON DRIER.]
It is very convenient to have a large copper water oven, containing a lot
of small separate compartments, large enough to hold about a handful of the
cotton, and each compartment numbered, and corresponding to one of the
drying cylinders. The whole apparatus should be fixed against the wall of
the laboratory, and may be heated by bringing a small steam pipe from the
boiler-house. It is useful to have a series of copper trays, about 3 inches by
6 inches, numbered to correspond to the divisions in the steam oven, and
exactly fitting them. These trays can then be taken by a boy to the drying
cylinders, and a handful of the cotton from each placed in them, and
afterwards brought to the laboratory and weighed (a boy can do this very
well), placed in their respective divisions of the oven, and left for one to
one and a half hours, and re-weighed.
When the cotton is found to be dry the bottom of the drying cylinder is
removed, and the cotton pushed out from the top by means of a piece of flat
wood fixed on a broom-handle. It is then packed away in galvanised- iron
air-tight cases, and is ready for the next operation. At some works the cotton
is dried upon shelves in a drying house through which hot air circulates, the
shelves being of canvas or of brass wire netting. The hot air must pass
under the shelves and through the cotton, or the process will be a very slow
one.
[A]) for an hour to an hour and a half, and re-weighed, and the moisture
then remaining in it calculated.
[Footnote A: It is dried at 180° C. at Waltham Abbey, in a specially
constructed drying chamber.]
[Illustration: FIG. 10.—COTTON DRIER.]
It is very convenient to have a large copper water oven, containing a lot
of small separate compartments, large enough to hold about a handful of the
cotton, and each compartment numbered, and corresponding to one of the
drying cylinders. The whole apparatus should be fixed against the wall of
the laboratory, and may be heated by bringing a small steam pipe from the
boiler-house. It is useful to have a series of copper trays, about 3 inches by
6 inches, numbered to correspond to the divisions in the steam oven, and
exactly fitting them. These trays can then be taken by a boy to the drying
cylinders, and a handful of the cotton from each placed in them, and
afterwards brought to the laboratory and weighed (a boy can do this very
well), placed in their respective divisions of the oven, and left for one to
one and a half hours, and re-weighed.
When the cotton is found to be dry the bottom of the drying cylinder is
removed, and the cotton pushed out from the top by means of a piece of flat
wood fixed on a broom-handle. It is then packed away in galvanised- iron
air-tight cases, and is ready for the next operation. At some works the cotton
is dried upon shelves in a drying house through which hot air circulates, the
shelves being of canvas or of brass wire netting. The hot air must pass
under the shelves and through the cotton, or the process will be a very slow
one.
Page 73
~Dipping and Steeping.~—The dry cotton has now to be nitrated. This is
done by dipping it into a mixture of nitric and sulphuric acids. The acids
used must be strong, that is, the nitric acid must be at least of a gravity of
1.53 to 1.52, and should contain as little nitric oxide as possible. The
sulphuric acid must have a specific gravity of 1.84 at 15° C., and contain
about 97 per cent. of the mono-hydrate (H_{2}SO_{4}). In fact, the
strongest acids obtainable should be used when the product required is gun-
cotton, i.e., the highest nitrate.
The sulphuric acid takes no part in the chemical reaction involved, but is
necessary in order to combine with the water that is liberated in the
reaction, and thus to maintain the strength of the nitric acid. The reaction
which takes place is the following:—
2(C_{6}H_{10}O_{5}) + 6HNO_{3} = C_{12}H_{14}(NO_{3}){6} +
6 H{2}O.
324 378 = 594 108.
Cellulose. Gun-Cotton.
Theoretically,[A] therefore, 1 part of cellulose should form 1.8 part of
gun-cotton. Practically, however, this is never obtained, and 1.6 lb. from 1
lb. of cellulose is very good working. The mixture of acids used is generally
1 to 3, or 25 per cent. nitric acid to 75 per cent. sulphuric acid.
[Footnote A: (594 x 1)/324= 1.83.]
[Illustration: FIG. 11.—TANK FOR DIPPING COTTON.]
[Illustration: FIG. 12.—THE COOLING PITS.]
The dipping is done in cast-iron tanks (Fig. 11), a series of which is
arranged in a row, and cooled by a stream of cold water flowing round
done by dipping it into a mixture of nitric and sulphuric acids. The acids
used must be strong, that is, the nitric acid must be at least of a gravity of
1.53 to 1.52, and should contain as little nitric oxide as possible. The
sulphuric acid must have a specific gravity of 1.84 at 15° C., and contain
about 97 per cent. of the mono-hydrate (H_{2}SO_{4}). In fact, the
strongest acids obtainable should be used when the product required is gun-
cotton, i.e., the highest nitrate.
The sulphuric acid takes no part in the chemical reaction involved, but is
necessary in order to combine with the water that is liberated in the
reaction, and thus to maintain the strength of the nitric acid. The reaction
which takes place is the following:—
2(C_{6}H_{10}O_{5}) + 6HNO_{3} = C_{12}H_{14}(NO_{3}){6} +
6 H{2}O.
324 378 = 594 108.
Cellulose. Gun-Cotton.
Theoretically,[A] therefore, 1 part of cellulose should form 1.8 part of
gun-cotton. Practically, however, this is never obtained, and 1.6 lb. from 1
lb. of cellulose is very good working. The mixture of acids used is generally
1 to 3, or 25 per cent. nitric acid to 75 per cent. sulphuric acid.
[Footnote A: (594 x 1)/324= 1.83.]
[Illustration: FIG. 11.—TANK FOR DIPPING COTTON.]
[Illustration: FIG. 12.—THE COOLING PITS.]
The dipping is done in cast-iron tanks (Fig. 11), a series of which is
arranged in a row, and cooled by a stream of cold water flowing round
Page 74
them. The tanks hold about 12 gallons, and the cotton is dipped in portions
of 1 lb. at a time. It is thrown into the acids, and the workman moves it
about for about three minutes with an iron rabble. At the end of that time he
lifts it up on to an iron grating, just above the acids, fixed at the back of the
tank, where by means of a movable lever he gently squeezes it, until it
contains about ten times its weight of acids (the 1 lb. weighs 10 lbs.). It is
then transferred to earthenware pots to steep.
[Illustration: FIG. 13.—COTTON STEEPING POT.]
~Steeping.~—The nitrated cotton, when withdrawn from the dipping
tanks, and still containing an excess of acids, is put into earthenware pots of
the shape shown in Figs. 12 and 13. The lid is put on, and the pots placed in
rows in large cooling pits, about a foot deep, through which a stream of
water is constantly flowing. These pits form the floor of the steeping house.
The cotton remains in these pots for a period of forty-eight hours, and must
be kept cool. Between 18° and 19° C. is the highest temperature desirable,
but the cooler the pots are kept the better. At the end of forty-eight hours the
chemical reaction is complete, and the cotton is or should be wholly
converted into nitro-cellulose; that is, there should be no unnitrated cotton.
[Illustration: FIG. 14.—HYDRO-EXTRACTOR.]
~Whirling Out the Acid.~—The next operation is to remove the excess of
acid. This is done by placing the contents of two or three or more pots into a
centrifugal hydro-extractor (Fig. 14), making 1,000 to 1,500 revolutions per
minute. The hydro-extractor consists of a machine with both an inner
cylinder and an outer one, both revolving in concert and driving outwardly
the liquid to the chamber, from which it runs away by a discharge pipe. The
wet cotton is placed around the inner cone. The cotton, when dry, is
removed, and at once thrown into a large tank of water, and the waste acids
are collected in a tank.[A]
of 1 lb. at a time. It is thrown into the acids, and the workman moves it
about for about three minutes with an iron rabble. At the end of that time he
lifts it up on to an iron grating, just above the acids, fixed at the back of the
tank, where by means of a movable lever he gently squeezes it, until it
contains about ten times its weight of acids (the 1 lb. weighs 10 lbs.). It is
then transferred to earthenware pots to steep.
[Illustration: FIG. 13.—COTTON STEEPING POT.]
~Steeping.~—The nitrated cotton, when withdrawn from the dipping
tanks, and still containing an excess of acids, is put into earthenware pots of
the shape shown in Figs. 12 and 13. The lid is put on, and the pots placed in
rows in large cooling pits, about a foot deep, through which a stream of
water is constantly flowing. These pits form the floor of the steeping house.
The cotton remains in these pots for a period of forty-eight hours, and must
be kept cool. Between 18° and 19° C. is the highest temperature desirable,
but the cooler the pots are kept the better. At the end of forty-eight hours the
chemical reaction is complete, and the cotton is or should be wholly
converted into nitro-cellulose; that is, there should be no unnitrated cotton.
[Illustration: FIG. 14.—HYDRO-EXTRACTOR.]
~Whirling Out the Acid.~—The next operation is to remove the excess of
acid. This is done by placing the contents of two or three or more pots into a
centrifugal hydro-extractor (Fig. 14), making 1,000 to 1,500 revolutions per
minute. The hydro-extractor consists of a machine with both an inner
cylinder and an outer one, both revolving in concert and driving outwardly
the liquid to the chamber, from which it runs away by a discharge pipe. The
wet cotton is placed around the inner cone. The cotton, when dry, is
removed, and at once thrown into a large tank of water, and the waste acids
are collected in a tank.[A]
Page 75
[Footnote A: Care must be taken in hot weather that the gun-cotton does
not fire, as it does sometimes, directly the workman goes to remove it after
the machine is stopped. It occurs more often in damp weather. Dr
Schüpphaus, of Brooklyn, U.S.A., proposes to treat the waste acids from the
nitration of cellulose by adding to them sulphuric anhydride and nitric acid.
The sulphuric anhydride added converts the water liberated from the
cellulose into sulphuric acid.]
~Washing.~—The cotton has now to be carefully washed. This is done in
a large wooden tank filled with water. If, however, a river or canal runs
through the works, a series of wooden tanks, the sides and bottoms of which
are pierced with holes, so as to allow of the free circulation of water, should
be sunk into a wooden platform that overhangs the surface of the river in
such a way that the tanks are immersed in the water, and of course always
full. During the time that the cotton is in the water a workman turns it over
constantly with a wooden paddle. A stream of water, in the form of a
cascade, should be allowed to fall into these tanks. The cotton may then be
thrown on to this stream of water, which, falling some height, at once
carries the cotton beneath the surface of the water. This proceeding is
necessary because the cotton still retains a large excess of strong acids, and
when mixed with water gives rise to considerable heat, especially if mixed
slowly with water. After the cotton has been well washed, it is again wrung
out in a centrifugal machine, and afterwards allowed to steep in water for
some time.
[Illustration: FIG. 15_a_.—THE BEATER FOR GUN-COTTON.]
~Boiling.~—The washed cotton is put into large iron boilers with plenty
of water, and boiled for some time at 100° C. In some works lead-lined
tanks are used, into which a steam pipe is led. The soluble impurities of
unstable character, to which Sir F.A. Abel traced the liability of gun- cotton
not fire, as it does sometimes, directly the workman goes to remove it after
the machine is stopped. It occurs more often in damp weather. Dr
Schüpphaus, of Brooklyn, U.S.A., proposes to treat the waste acids from the
nitration of cellulose by adding to them sulphuric anhydride and nitric acid.
The sulphuric anhydride added converts the water liberated from the
cellulose into sulphuric acid.]
~Washing.~—The cotton has now to be carefully washed. This is done in
a large wooden tank filled with water. If, however, a river or canal runs
through the works, a series of wooden tanks, the sides and bottoms of which
are pierced with holes, so as to allow of the free circulation of water, should
be sunk into a wooden platform that overhangs the surface of the river in
such a way that the tanks are immersed in the water, and of course always
full. During the time that the cotton is in the water a workman turns it over
constantly with a wooden paddle. A stream of water, in the form of a
cascade, should be allowed to fall into these tanks. The cotton may then be
thrown on to this stream of water, which, falling some height, at once
carries the cotton beneath the surface of the water. This proceeding is
necessary because the cotton still retains a large excess of strong acids, and
when mixed with water gives rise to considerable heat, especially if mixed
slowly with water. After the cotton has been well washed, it is again wrung
out in a centrifugal machine, and afterwards allowed to steep in water for
some time.
[Illustration: FIG. 15_a_.—THE BEATER FOR GUN-COTTON.]
~Boiling.~—The washed cotton is put into large iron boilers with plenty
of water, and boiled for some time at 100° C. In some works lead-lined
tanks are used, into which a steam pipe is led. The soluble impurities of
unstable character, to which Sir F.A. Abel traced the liability of gun- cotton
Page 76
to instability, are thereby removed. These impurities consist of the products
formed by the action of nitric acid on the fatty and resinous substances
contained in the cotton fibres. The water in the tanks should be every now
and again renewed, and after the first few boilings the water should be
tested with litmus paper until they are no longer found to be acid.
[Illustration: FIG. 15_b_.—WHEEL OF BEATER.]
~Pulping.~—The idea of pulping is also due to Abel. By its means a very
much more uniform material is obtained. The process is carried out in an
apparatus known as a "Beater" or "Hollander" (Fig. 15, a, b). It consists of a
kind of wooden tank some 2 or 3 feet deep of an oblong shape, in which a
wheel carrying a series of knives is made to revolve, the floor of the tank
being sloped up so as to almost touch the revolving wheels. This part of the
floor, known as the "craw," is a solid piece of oak, and a box of knives is
fixed into it, against which the knives in the revolving wheel are pressed.
The beater is divided into two parts—the working side, in which the cotton
is cut and torn between the knife edges in the revolving cylinder and those
in the box; and the running side, into which the cotton passes after passing
under the cylinder. The wheel is generally boxed in to prevent the cotton
from being thrown out during its revolution. The cotton is thus in constant
motion, continually travelling round, and passing between the knives in the
revolving cylinder and those in the box fixed in the wooden block beneath
it. The beater is kept full of water, and the cotton is gradually reduced to a
condition of pulp. The wheel revolves at the rate of 100 to 150 times a
minute.
[Illustration: FIG. 16_a_.—POACHER FOR WASHING GUN-
COTTON.]
[Illustration: FIG. 16_b_.—PLAN OF THE POACHER.]
formed by the action of nitric acid on the fatty and resinous substances
contained in the cotton fibres. The water in the tanks should be every now
and again renewed, and after the first few boilings the water should be
tested with litmus paper until they are no longer found to be acid.
[Illustration: FIG. 15_b_.—WHEEL OF BEATER.]
~Pulping.~—The idea of pulping is also due to Abel. By its means a very
much more uniform material is obtained. The process is carried out in an
apparatus known as a "Beater" or "Hollander" (Fig. 15, a, b). It consists of a
kind of wooden tank some 2 or 3 feet deep of an oblong shape, in which a
wheel carrying a series of knives is made to revolve, the floor of the tank
being sloped up so as to almost touch the revolving wheels. This part of the
floor, known as the "craw," is a solid piece of oak, and a box of knives is
fixed into it, against which the knives in the revolving wheel are pressed.
The beater is divided into two parts—the working side, in which the cotton
is cut and torn between the knife edges in the revolving cylinder and those
in the box; and the running side, into which the cotton passes after passing
under the cylinder. The wheel is generally boxed in to prevent the cotton
from being thrown out during its revolution. The cotton is thus in constant
motion, continually travelling round, and passing between the knives in the
revolving cylinder and those in the box fixed in the wooden block beneath
it. The beater is kept full of water, and the cotton is gradually reduced to a
condition of pulp. The wheel revolves at the rate of 100 to 150 times a
minute.
[Illustration: FIG. 16_a_.—POACHER FOR WASHING GUN-
COTTON.]
[Illustration: FIG. 16_b_.—PLAN OF THE POACHER.]
Page 77
[Illustration: FIG. 16_c_.—ANOTHER FORM OF POACHER.]
When the gun-cotton is judged to be sufficiently fine, the contents of the
beater are run into another very similar piece of machinery, known as the
"poacher" (Fig. 16, a, b, c), in which the gun-cotton is continuously agitated
together with a large quantity of water, which can be easily run off and
replaced as often as required. When the material is first run into the poacher
from the beater, the water with which it is then mixed is first run away and
clean water added. The paddle wheel is then set in motion, and at intervals
fresh water is added. There is a strainer at the bottom of the poacher which
enables the water to be drawn off without disturbing the cotton pulp. After
the gun-cotton has been in the poacher for some time, a sample should be
taken by holding a rather large mesh sieve in the current for a minute or so.
The pulp will thus partly pass through and partly be caught upon the sieve,
and an average sample will be thus obtained. The sample is squeezed out by
hand, bottled, and taken to the laboratory to be tested by the heat test for
purity. It first, however, requires to be dried. This is best done by placing
the sample between coarse filter paper, and then putting it under a hand-
screw press, where it can be subjected to a tolerably severe pressure for
about three minutes. It is then rubbed up very finely with the hands, and
placed upon a paper tray, about 6 inches by 4-1/2 inches, which is then
placed inside a water oven upon a shelf of coarse wire gauze, the
temperature of the oven being kept as near as possible to 120° F. (49° C.),
the gauze shelves in the oven being kept about 3 inches apart. The sample is
allowed to remain at rest for fifteen minutes in the oven, the door of which
is left wide open. After the lapse of fifteen minutes the tray is removed and
exposed to the air of the laboratory (away from acid fumes) for two hours,
the sample being at some point within that time rubbed upon the tray with
the hand, in order to reduce it to a fine and uniform state of division.
Twenty grains (1.296 grm.) are used for the test. (See Heat Test, page 249.)
When the gun-cotton is judged to be sufficiently fine, the contents of the
beater are run into another very similar piece of machinery, known as the
"poacher" (Fig. 16, a, b, c), in which the gun-cotton is continuously agitated
together with a large quantity of water, which can be easily run off and
replaced as often as required. When the material is first run into the poacher
from the beater, the water with which it is then mixed is first run away and
clean water added. The paddle wheel is then set in motion, and at intervals
fresh water is added. There is a strainer at the bottom of the poacher which
enables the water to be drawn off without disturbing the cotton pulp. After
the gun-cotton has been in the poacher for some time, a sample should be
taken by holding a rather large mesh sieve in the current for a minute or so.
The pulp will thus partly pass through and partly be caught upon the sieve,
and an average sample will be thus obtained. The sample is squeezed out by
hand, bottled, and taken to the laboratory to be tested by the heat test for
purity. It first, however, requires to be dried. This is best done by placing
the sample between coarse filter paper, and then putting it under a hand-
screw press, where it can be subjected to a tolerably severe pressure for
about three minutes. It is then rubbed up very finely with the hands, and
placed upon a paper tray, about 6 inches by 4-1/2 inches, which is then
placed inside a water oven upon a shelf of coarse wire gauze, the
temperature of the oven being kept as near as possible to 120° F. (49° C.),
the gauze shelves in the oven being kept about 3 inches apart. The sample is
allowed to remain at rest for fifteen minutes in the oven, the door of which
is left wide open. After the lapse of fifteen minutes the tray is removed and
exposed to the air of the laboratory (away from acid fumes) for two hours,
the sample being at some point within that time rubbed upon the tray with
the hand, in order to reduce it to a fine and uniform state of division.
Twenty grains (1.296 grm.) are used for the test. (See Heat Test, page 249.)
Page 78
If the gun-cotton sample removed from the poacher stands the heat test
satisfactorily, the machine is stopped, and the water drained off. The cotton
is allowed some little time to drain, and is then dug out by means of
wooden spades, and is then ready for pressing. The poachers hold about
2,000 lbs. of material, and as this represents the products of many hundred
distinct nitrating operations, a very uniform mixture is obtained. Two per
cent. of carbonate of soda is sometimes added, but it is not really necessary
if the cotton has been properly washed.
~Compressing Gun-Cotton.~—The gun-cotton, in the state in which it is
removed from the poacher, contains from 28 to 30 per cent. of water. In
order to remove this, the cotton has to be compressed by hydraulic power.
The dry compressed gun-cotton is packed in boxes containing 2,500 lbs. of
dry material. In order to ascertain how much of the wet cotton must be put
into the press, it is necessary to determine the percentage of water. This may
be done by drying 2,000 grains upon a paper tray (previously dried at 100°
C.) in the water oven at 100° C. for three hours, and re-weighing and
calculating the percentage of water. It is then easy to calculate how much of
the wet gun-cotton must be placed in the hopper of the press in order to
obtain a block of compressed cotton of the required weight. Various forms
of presses are used, and gun-cotton is sent out either as solid blocks,
compressed discs, or in the form of an almost dry powder, in zinc- lined,
air-tight cases. The discs are often soaked in water after compression until
they have absorbed 25 per cent. of moisture.
[Illustration: FIG. 17.—OLD METHOD. 100 PIECES.]
[Illustration: FIG. 18.—NEW METHOD. ONE SOLID BLOCK.]
At the New Explosives Company's Stowmarket Works large solid blocks
of gun-cotton are pressed up under a new process, whereby blocks of gun-
cotton, for use in submarine mines or in torpedo warheads, are produced.
satisfactorily, the machine is stopped, and the water drained off. The cotton
is allowed some little time to drain, and is then dug out by means of
wooden spades, and is then ready for pressing. The poachers hold about
2,000 lbs. of material, and as this represents the products of many hundred
distinct nitrating operations, a very uniform mixture is obtained. Two per
cent. of carbonate of soda is sometimes added, but it is not really necessary
if the cotton has been properly washed.
~Compressing Gun-Cotton.~—The gun-cotton, in the state in which it is
removed from the poacher, contains from 28 to 30 per cent. of water. In
order to remove this, the cotton has to be compressed by hydraulic power.
The dry compressed gun-cotton is packed in boxes containing 2,500 lbs. of
dry material. In order to ascertain how much of the wet cotton must be put
into the press, it is necessary to determine the percentage of water. This may
be done by drying 2,000 grains upon a paper tray (previously dried at 100°
C.) in the water oven at 100° C. for three hours, and re-weighing and
calculating the percentage of water. It is then easy to calculate how much of
the wet gun-cotton must be placed in the hopper of the press in order to
obtain a block of compressed cotton of the required weight. Various forms
of presses are used, and gun-cotton is sent out either as solid blocks,
compressed discs, or in the form of an almost dry powder, in zinc- lined,
air-tight cases. The discs are often soaked in water after compression until
they have absorbed 25 per cent. of moisture.
[Illustration: FIG. 17.—OLD METHOD. 100 PIECES.]
[Illustration: FIG. 18.—NEW METHOD. ONE SOLID BLOCK.]
At the New Explosives Company's Stowmarket Works large solid blocks
of gun-cotton are pressed up under a new process, whereby blocks of gun-
cotton, for use in submarine mines or in torpedo warheads, are produced.
Page 79
Large charges of compressed gun-cotton have hitherto been built up from a
number of suitably shaped charges of small dimensions (Fig. 17), as it has
been impossible to compress large charges in a proper manner. The
formation of large-sized blocks of gun-cotton was the invention of Mr A.
Hollings. Prior to the introduction of this method, 8 or 9 lbs. had been the
limit of weight for a block. This process has been perfected at the
Stowmarket factory, where blocks varying from the armour-piercing shell
charge of a few ounces up to blocks of compressed gun-cotton
mechanically true, weighing 4 to 5 cwts. for torpedoes or submarine mines,
are now produced. At the same time the new process ensures a uniform
density throughout the block, and permits of any required density, from 1.4
downwards, being attained; it is also possible exactly to regulate the
percentage of moisture, and to ensure its uniform distribution. The
maximum percentage of moisture depends, of course, upon the density. By
the methods of compression gun-cotton blocks hitherto employed, blocks of
a greater thickness than 2 inches, or of a greater weight than 9 lbs., could
not be made, but with the new process blocks of any shape, size, thickness,
or weight that is likely to be required can be made readily and safely. The
advantages which are claimed for the process may be enumerated as
follows:—(1.) There is no space wasted, as in the case with built-up
charges, through slightly imperfect contact between the individual blocks,
and thus either a heavier charge—i.e., about 15 per cent. more gun- cotton
—can be got into the same space, or less space will be occupied by a charge
of a given weight. (2.) The metallic cases for solid charges may be much
lighter than for those built-up, since with the former their function is merely
to prevent the loss of moisture from wet gun-cotton, or to prevent the
absorption of moisture by dry gun-cotton. They can thus be made lighter, as
the solid charge inside will prevent deformation during transport. With
built-up charges the case must be strong enough to prevent damage, either
to itself or to the charge it contains. For many uses a metal case, however
number of suitably shaped charges of small dimensions (Fig. 17), as it has
been impossible to compress large charges in a proper manner. The
formation of large-sized blocks of gun-cotton was the invention of Mr A.
Hollings. Prior to the introduction of this method, 8 or 9 lbs. had been the
limit of weight for a block. This process has been perfected at the
Stowmarket factory, where blocks varying from the armour-piercing shell
charge of a few ounces up to blocks of compressed gun-cotton
mechanically true, weighing 4 to 5 cwts. for torpedoes or submarine mines,
are now produced. At the same time the new process ensures a uniform
density throughout the block, and permits of any required density, from 1.4
downwards, being attained; it is also possible exactly to regulate the
percentage of moisture, and to ensure its uniform distribution. The
maximum percentage of moisture depends, of course, upon the density. By
the methods of compression gun-cotton blocks hitherto employed, blocks of
a greater thickness than 2 inches, or of a greater weight than 9 lbs., could
not be made, but with the new process blocks of any shape, size, thickness,
or weight that is likely to be required can be made readily and safely. The
advantages which are claimed for the process may be enumerated as
follows:—(1.) There is no space wasted, as in the case with built-up
charges, through slightly imperfect contact between the individual blocks,
and thus either a heavier charge—i.e., about 15 per cent. more gun- cotton
—can be got into the same space, or less space will be occupied by a charge
of a given weight. (2.) The metallic cases for solid charges may be much
lighter than for those built-up, since with the former their function is merely
to prevent the loss of moisture from wet gun-cotton, or to prevent the
absorption of moisture by dry gun-cotton. They can thus be made lighter, as
the solid charge inside will prevent deformation during transport. With
built-up charges the case must be strong enough to prevent damage, either
to itself or to the charge it contains. For many uses a metal case, however
Page 80
light, may be discarded, and one of a thin waterproof material substituted.
(3.) The uniform density of charges made by this process is very favourable
to the complete and effective detonation of the entire mass, and to the
presence of the uniform amount of moisture in every part of the charge. (4.)
Any required density, from the maximum downwards, may be obtained
with ease, and any required amount of moisture left in the charge. These
points are of great importance in cases where, like torpedo charges, it is
essential to have the centre of gravity of the charge in a predetermined
position both vertically and longitudinally, and the charge so fixed in its
containing case that the centre of gravity cannot shift. The difficulty of
ensuring this with a large torpedo charge built up from a number of discs
and segments is well known. Even with plain cylindrical or prismatic
charges a marked saving in the process of production is effected by this new
system. The charges being in one block they are more easily handled for the
usual periodical examination, and they do not break or chafe at the edges, as
in the case of discs and cubes in built-up charges. A general view of the
press is given in Fig. 19. The gun-cotton in a container is placed on a cradle
fixed at an angle to the press. The mould is swivelled round, and the charge
pushed into it with a rammer, and it is then swivelled back into position.
The mould is made up of a number of wedge pieces which close
circumferentially on the enclosed mass, which is also subjected to end
pressure. Holes are provided for the escape of water.
[Illustration: FIG. 19.—A 4-CWT. BLOCK OF GUN-COTTON BEING
TAKEN FROM
HYDRAULIC PRESS.]
~The Waltham Abbey Process.~—At the Royal Gunpowder Factory,
Waltham Abbey, the manufacture of gun-cotton has been carried out for
many years. The process used differs but little from that used at
Stowmarket. The cotton used is of a good quality, it is sorted and picked
(3.) The uniform density of charges made by this process is very favourable
to the complete and effective detonation of the entire mass, and to the
presence of the uniform amount of moisture in every part of the charge. (4.)
Any required density, from the maximum downwards, may be obtained
with ease, and any required amount of moisture left in the charge. These
points are of great importance in cases where, like torpedo charges, it is
essential to have the centre of gravity of the charge in a predetermined
position both vertically and longitudinally, and the charge so fixed in its
containing case that the centre of gravity cannot shift. The difficulty of
ensuring this with a large torpedo charge built up from a number of discs
and segments is well known. Even with plain cylindrical or prismatic
charges a marked saving in the process of production is effected by this new
system. The charges being in one block they are more easily handled for the
usual periodical examination, and they do not break or chafe at the edges, as
in the case of discs and cubes in built-up charges. A general view of the
press is given in Fig. 19. The gun-cotton in a container is placed on a cradle
fixed at an angle to the press. The mould is swivelled round, and the charge
pushed into it with a rammer, and it is then swivelled back into position.
The mould is made up of a number of wedge pieces which close
circumferentially on the enclosed mass, which is also subjected to end
pressure. Holes are provided for the escape of water.
[Illustration: FIG. 19.—A 4-CWT. BLOCK OF GUN-COTTON BEING
TAKEN FROM
HYDRAULIC PRESS.]
~The Waltham Abbey Process.~—At the Royal Gunpowder Factory,
Waltham Abbey, the manufacture of gun-cotton has been carried out for
many years. The process used differs but little from that used at
Stowmarket. The cotton used is of a good quality, it is sorted and picked
Page 81
over to remove foreign matters, &c., and is then cut up by a kind of
guillotine into 2-inch lengths. It is then dried in the following manner. The
cotton is placed upon an endless band, which conducts it to the stove, or
drying closet, a chamber heated by means of hot air and steam traps to
about 180° F.; it falls upon a second endless band, placed below the first; it
travels back again the whole length of the stove, and so on until delivered
into a receptacle at the bottom of the farther end, where it is kept dry until
required for use. The speed at which the cotton travels is 6 feet per minute,
and as the length of the band travelled amounts to 126 feet, the operation of
drying takes twenty-one minutes. One and a quarter lb. are weighed out and
placed in a tin box; a truck, fitted to receive a number of these boxes,
carries it along a tramway to a cool room, where it is allowed to cool.
~Dipping.~—Mixed acids are used in the proportion of 1 to 3, specific
gravity nitric acid 1.52, and sulphuric acid 1.84. The dipping tank is made
of cast iron, and holds 220 lbs. of mixed acids, and is surrounded on three
sides by a water space in order to keep it cool. The mixed acids are stored in
iron tanks behind the dipping tanks, and are allowed to cool before use.
During the nitration, the temperature of the mixed acids is kept at 70° F.,
and the cotton is dipped in quantities of 1-1/2 lb. at a time. It is put into a tin
shoot at the back of the dipping tank, and raked into the acids by means of a
rabble. It remains in the acids for five or six minutes, and is then removed
to a grating at the back, pressed and removed. After each charge of cotton is
removed from the tank, about 14 lbs. of fresh mixed acids are added, to
replace amount removed by charge. The charge now weighs, with the acids
retained by it, 15 lbs.; it is now placed in the pots, and left to steep for at
least twenty-four hours, the temperature being kept as low as possible, to
prevent the formation of soluble cotton, and also prevent firing. The
proportion of soluble formed is likely to be higher in hot weather than cold.
The pots must be covered to prevent the absorption of moisture from the air,
or the accidental entrance of water, which would cause decomposition, and
guillotine into 2-inch lengths. It is then dried in the following manner. The
cotton is placed upon an endless band, which conducts it to the stove, or
drying closet, a chamber heated by means of hot air and steam traps to
about 180° F.; it falls upon a second endless band, placed below the first; it
travels back again the whole length of the stove, and so on until delivered
into a receptacle at the bottom of the farther end, where it is kept dry until
required for use. The speed at which the cotton travels is 6 feet per minute,
and as the length of the band travelled amounts to 126 feet, the operation of
drying takes twenty-one minutes. One and a quarter lb. are weighed out and
placed in a tin box; a truck, fitted to receive a number of these boxes,
carries it along a tramway to a cool room, where it is allowed to cool.
~Dipping.~—Mixed acids are used in the proportion of 1 to 3, specific
gravity nitric acid 1.52, and sulphuric acid 1.84. The dipping tank is made
of cast iron, and holds 220 lbs. of mixed acids, and is surrounded on three
sides by a water space in order to keep it cool. The mixed acids are stored in
iron tanks behind the dipping tanks, and are allowed to cool before use.
During the nitration, the temperature of the mixed acids is kept at 70° F.,
and the cotton is dipped in quantities of 1-1/2 lb. at a time. It is put into a tin
shoot at the back of the dipping tank, and raked into the acids by means of a
rabble. It remains in the acids for five or six minutes, and is then removed
to a grating at the back, pressed and removed. After each charge of cotton is
removed from the tank, about 14 lbs. of fresh mixed acids are added, to
replace amount removed by charge. The charge now weighs, with the acids
retained by it, 15 lbs.; it is now placed in the pots, and left to steep for at
least twenty-four hours, the temperature being kept as low as possible, to
prevent the formation of soluble cotton, and also prevent firing. The
proportion of soluble formed is likely to be higher in hot weather than cold.
The pots must be covered to prevent the absorption of moisture from the air,
or the accidental entrance of water, which would cause decomposition, and
Page 82
consequent fuming off, through the heat generated by the action of the
water upon the strong acids.
The excess of acids is now extracted by means of hydro-extractors, as at
Stowmarket. They are worked at 1,200 revolutions per minute, and whirled
for five minutes (10-1/2 lbs. of waste acids are removed from each charge
dipped). The charge is then washed in a very similar manner to that
previously described, and again wrung out in a centrifugal extractor (1,200
revolutions per minute). The gun-cotton is now boiled by means of steam in
wooden tanks for eight hours; it is then again wrung out in the extractors for
three minutes, boiled for eight hours more, and again wrung out; it is then
sent to the beater and afterwards to the poacher. The poachers hold 1,500
gals. each, or 18 cwt. of cotton. The cotton remains six hours in the
poachers. Before moulding, 500 gals. of water are run into the poacher, and
500 gals. of lime water containing 9 lbs. of whiting and 9 gals. of a caustic
soda solution. This mixture is of such a strength that it is calculated to leave
in the finished gun-cotton from 1 to 2 per cent. of alkaline matter.
By means of vacuum pressure, the pulp is now drawn off and up into the
stuff chest—a large cylindrical iron tank, sufficiently elevated on iron
standards to allow room for the small gauge tanks and moulding apparatus
below. It holds the contents of one poacher (18 cwt.), and is provided with
revolving arms to keep the pulp stirred up, so that it may be uniformly
suspended in water.
Recently a new process, invented by J.M. and W.T. Thomson (Eng. Pat.
No. 8,278, 1903), has been introduced at the Waltham Abbey Factory. The
object of this invention is the removal of the acids of nitration from the
nitrated material after the action has been completed, and without the aid of
moving machinery, such as presses, rollers, centrifugals, and the like. The
invention consists in the manufacture of nitrated celluloses by removing the
water upon the strong acids.
The excess of acids is now extracted by means of hydro-extractors, as at
Stowmarket. They are worked at 1,200 revolutions per minute, and whirled
for five minutes (10-1/2 lbs. of waste acids are removed from each charge
dipped). The charge is then washed in a very similar manner to that
previously described, and again wrung out in a centrifugal extractor (1,200
revolutions per minute). The gun-cotton is now boiled by means of steam in
wooden tanks for eight hours; it is then again wrung out in the extractors for
three minutes, boiled for eight hours more, and again wrung out; it is then
sent to the beater and afterwards to the poacher. The poachers hold 1,500
gals. each, or 18 cwt. of cotton. The cotton remains six hours in the
poachers. Before moulding, 500 gals. of water are run into the poacher, and
500 gals. of lime water containing 9 lbs. of whiting and 9 gals. of a caustic
soda solution. This mixture is of such a strength that it is calculated to leave
in the finished gun-cotton from 1 to 2 per cent. of alkaline matter.
By means of vacuum pressure, the pulp is now drawn off and up into the
stuff chest—a large cylindrical iron tank, sufficiently elevated on iron
standards to allow room for the small gauge tanks and moulding apparatus
below. It holds the contents of one poacher (18 cwt.), and is provided with
revolving arms to keep the pulp stirred up, so that it may be uniformly
suspended in water.
Recently a new process, invented by J.M. and W.T. Thomson (Eng. Pat.
No. 8,278, 1903), has been introduced at the Waltham Abbey Factory. The
object of this invention is the removal of the acids of nitration from the
nitrated material after the action has been completed, and without the aid of
moving machinery, such as presses, rollers, centrifugals, and the like. The
invention consists in the manufacture of nitrated celluloses by removing the
Page 83
acids from the nitrated cellulose directly by displacement without the
employment of either pressure or vacuum or mechanical appliances of any
kind, and at the same time securing the minimum dilution of the acids. It
was found that if water was carefully run on to the surface of the acids in
which the nitro-cellulose is immersed, and the acids be slowly drawn off at
the bottom of the vessel, the water displaces the acid from the interstices of
the nitro-cellulose without any undesirable rise in temperature, and with
very little dilution of the acids. By this process almost the whole of the acid
is recovered in a condition suitable for concentration, and the amount of
water required for preliminary washing is very greatly reduced. The
apparatus which is used for the purpose consists of a cylindrical or
rectangular vessel constructed with a perforated false bottom and a cock at
its lowest point for running off the liquid. Means are also provided to enable
the displacing water to be run quietly on to the surface of the nitrating acids.
[A]
[Footnote A: In a further patent (Eng. Pat. 7,269, 1903, F.L. Natham),
J.M. Thomson and W.T. Thomson propose by use of alcohol to replace the
water, used in washing nitro-cellulose, and afterward to remove the alcohol
by pressing and centrifuging.]
The apparatus is shown in Fig. 2O, side elevation, and in Fig. 21 a plan
of the nitrating vessel and its accessories is given. In Fig. 20 is shown in
sectional elevation one of the trough devices for enabling liquids to be
added to those in the nitrating vessel without substantial disturbance.
[Illustration: FIG. 20.—SECTIONAL ELEVATION OF THOMSON'S
APPARATUS, a, Tank; b, False Bottom; c, Bottom; c', Ribs; d, Draining
Outlet; e, Grid; f, Troughs, with Aprons g; h, Pipe, with Branches h', leading
to Troughs, f; k', Outlet Pipe of the Sulphuric Acid Tank k; l, Water Supply
employment of either pressure or vacuum or mechanical appliances of any
kind, and at the same time securing the minimum dilution of the acids. It
was found that if water was carefully run on to the surface of the acids in
which the nitro-cellulose is immersed, and the acids be slowly drawn off at
the bottom of the vessel, the water displaces the acid from the interstices of
the nitro-cellulose without any undesirable rise in temperature, and with
very little dilution of the acids. By this process almost the whole of the acid
is recovered in a condition suitable for concentration, and the amount of
water required for preliminary washing is very greatly reduced. The
apparatus which is used for the purpose consists of a cylindrical or
rectangular vessel constructed with a perforated false bottom and a cock at
its lowest point for running off the liquid. Means are also provided to enable
the displacing water to be run quietly on to the surface of the nitrating acids.
[A]
[Footnote A: In a further patent (Eng. Pat. 7,269, 1903, F.L. Natham),
J.M. Thomson and W.T. Thomson propose by use of alcohol to replace the
water, used in washing nitro-cellulose, and afterward to remove the alcohol
by pressing and centrifuging.]
The apparatus is shown in Fig. 2O, side elevation, and in Fig. 21 a plan
of the nitrating vessel and its accessories is given. In Fig. 20 is shown in
sectional elevation one of the trough devices for enabling liquids to be
added to those in the nitrating vessel without substantial disturbance.
[Illustration: FIG. 20.—SECTIONAL ELEVATION OF THOMSON'S
APPARATUS, a, Tank; b, False Bottom; c, Bottom; c', Ribs; d, Draining
Outlet; e, Grid; f, Troughs, with Aprons g; h, Pipe, with Branches h', leading
to Troughs, f; k', Outlet Pipe of the Sulphuric Acid Tank k; l, Water Supply
Page 84
Pipe; m, Pipe to supply of Nitrating Acids; o, Perforations of Trough f; p,
Cock to remove Acid.]
In carrying out this invention a rectangular lead-lined or earthenware
tank a is employed, having a false bottom b, supported by ribs c', over the
real bottom c, which slopes down to a draining outlet pipe d, provided with
a perforated grid or plate e, adapted to prevent choking of the outlet.
Suitably supported near the top of the vessel a are provided two troughs, f
having depending aprons g, a pipe h has two branches h', leading to the
troughs, f. This pipe h is adapted to be connected by a rubber pipe either to
the outlet pipe k' of the sulphuric acid tank k or the water supply pipe l. The
nitrating acids are supplied through the pipe m. A charge of mixed nitrating
acids is introduced into the vessel a say up to the level n, and the dry
cellulose thrown into the acids in small quantities at a time, being pushed
under the surface in the usual way.
[Illustration: FIG. 21.—PLAN OF THOMSON'S APPARATUS, a, Tank;
b,
False Bottom; c', Ribs; e, Grid; f, Troughs; g, Aprons; h and
h', Pipes to Troughs f; k, Sulphuric Acid Tank; m, Pipe to
Nitrating Acids Tank; o, Perforations of Troughs; p, Cock to remove
Acid.]
A thin layer, say half an inch, of a suitable liquid, preferably sulphuric
acid, of a gravity not exceeding that of the waste acid to be produced, is run
carefully on the top of the acids by means of the troughs f, which are
perforated as shown at o, so that the sulphuric acid runs down the aprons g,
and floats on the nitrating acids. The whole is then allowed to stand till
nitration has been completed. Water is then supplied to the troughs by way
of the pipes l, h, and h', and is allowed to float very gently over the surface
of the sulphuric acid, and when a sufficient layer has been formed, the cock
Cock to remove Acid.]
In carrying out this invention a rectangular lead-lined or earthenware
tank a is employed, having a false bottom b, supported by ribs c', over the
real bottom c, which slopes down to a draining outlet pipe d, provided with
a perforated grid or plate e, adapted to prevent choking of the outlet.
Suitably supported near the top of the vessel a are provided two troughs, f
having depending aprons g, a pipe h has two branches h', leading to the
troughs, f. This pipe h is adapted to be connected by a rubber pipe either to
the outlet pipe k' of the sulphuric acid tank k or the water supply pipe l. The
nitrating acids are supplied through the pipe m. A charge of mixed nitrating
acids is introduced into the vessel a say up to the level n, and the dry
cellulose thrown into the acids in small quantities at a time, being pushed
under the surface in the usual way.
[Illustration: FIG. 21.—PLAN OF THOMSON'S APPARATUS, a, Tank;
b,
False Bottom; c', Ribs; e, Grid; f, Troughs; g, Aprons; h and
h', Pipes to Troughs f; k, Sulphuric Acid Tank; m, Pipe to
Nitrating Acids Tank; o, Perforations of Troughs; p, Cock to remove
Acid.]
A thin layer, say half an inch, of a suitable liquid, preferably sulphuric
acid, of a gravity not exceeding that of the waste acid to be produced, is run
carefully on the top of the acids by means of the troughs f, which are
perforated as shown at o, so that the sulphuric acid runs down the aprons g,
and floats on the nitrating acids. The whole is then allowed to stand till
nitration has been completed. Water is then supplied to the troughs by way
of the pipes l, h, and h', and is allowed to float very gently over the surface
of the sulphuric acid, and when a sufficient layer has been formed, the cock
Page 85
p at the bottom of the apparatus is opened, and the acid slowly drawn off,
water being supplied to maintain the level constant. It is found that the rate
of displacement of the acids is a factor which exerts a considerable
influence on the properties of the resulting nitro-cellulose, and affords a
means of regulating the temperature of displacement. A rate of displacement
which has been found suitable is about two inches in depth of the vessel per
hour when treating highly nitrated celluloses, but this rate may, in some
cases, be considerably increased. The flow of water at the top of the
apparatus is regulated so that a constant level is maintained. By this means
the water gradually and entirely displaces the acids from the interstices of
the nitro-cellulose, the line of separation between the acids and the water
being fairly sharply defined throughout. The flow of water is continued
until that issuing at the bottom is found to be free from all trace of acid. The
purification of the nitro-cellulose is then proceeded with as usual, either in
the same vessel or another.
In the process above described, the object of the introduction of a small
layer of sulphuric acid is mainly to prevent the fuming which would
otherwise take place, and is not essential, as it is found it can be omitted
without any deleterious effect. In order to use the mixed acids in the most
economical manner, the waste acid from a previous operation may be used
for a first nitration of the cellulose; being afterwards displaced with fresh
acids which carry the nitration to the required degree before they are in turn
displaced by water. The apparatus may be used merely for the removal of
the acid, in which case the nitration is carried out in other vessels in the
usual way, and the nitro-cellulose removed to the displacement apparatus
where it is just covered with waste acid, and the displacement then
proceeded with as above described. In some cases the process is carried out
in an ordinary nitrating centrifugal, using the latter to effect preliminary
drying after acid extraction. This gives a great advantage over the usual
method of working ordinary centrifugal nitrating apparatus, because the
water being supplied to maintain the level constant. It is found that the rate
of displacement of the acids is a factor which exerts a considerable
influence on the properties of the resulting nitro-cellulose, and affords a
means of regulating the temperature of displacement. A rate of displacement
which has been found suitable is about two inches in depth of the vessel per
hour when treating highly nitrated celluloses, but this rate may, in some
cases, be considerably increased. The flow of water at the top of the
apparatus is regulated so that a constant level is maintained. By this means
the water gradually and entirely displaces the acids from the interstices of
the nitro-cellulose, the line of separation between the acids and the water
being fairly sharply defined throughout. The flow of water is continued
until that issuing at the bottom is found to be free from all trace of acid. The
purification of the nitro-cellulose is then proceeded with as usual, either in
the same vessel or another.
In the process above described, the object of the introduction of a small
layer of sulphuric acid is mainly to prevent the fuming which would
otherwise take place, and is not essential, as it is found it can be omitted
without any deleterious effect. In order to use the mixed acids in the most
economical manner, the waste acid from a previous operation may be used
for a first nitration of the cellulose; being afterwards displaced with fresh
acids which carry the nitration to the required degree before they are in turn
displaced by water. The apparatus may be used merely for the removal of
the acid, in which case the nitration is carried out in other vessels in the
usual way, and the nitro-cellulose removed to the displacement apparatus
where it is just covered with waste acid, and the displacement then
proceeded with as above described. In some cases the process is carried out
in an ordinary nitrating centrifugal, using the latter to effect preliminary
drying after acid extraction. This gives a great advantage over the usual
method of working ordinary centrifugal nitrating apparatus, because the
Page 86
acid being removed before the centrifugal is run, practically all danger of
firing therein disappears, and a greater proportion of the waste acid is
recovered.
In some cases the acids and water may be supplied by perforated pipes,
lying along the edges of the nitrating vessel, and these edges may, if
desired, be themselves made inclined, like the sides of the troughs f. In the
case of effecting nitration in centrifugals as above, the displacing sulphuric
acid and water may thus be supplied round the edges of the machines, or
removal troughs such as f may be used. It will be obvious that any inert
liquid of suitable specific gravity may be used instead of sulphuric acid, as
a separation layer.
~Moulding.~—By means of the small measuring tank above referred to,
the gun-cotton pulp is drawn off from the stuff chest, and run into moulds
of the shapes and sizes required. Thence a large proportion of the water is
drawn off by means of tubes connected with the vacuum engine, the moulds
having bottoms of fine wire gauze, in order to prevent the pulp from
passing through. Hydraulic pressure of about 34 lbs. on the square inch is
then applied, which has the effect of compressing the pulp into a state in
which it has sufficient consistency to enable it to be handled with care, and
also expels a portion of the remaining water.
~Compressing.~—The moulded gun-cotton is now taken to the press
house, which is situated at some distance from the rest of the factory. Here
the moulds are subjected to powerful hydraulic pressure, from 5 to 6 tons
per square inch, and is compressed to one-third of its previous bulk. The
slabs or discs thus formed are kept under pressure for a short time, not
exceeding a minute and a half, to give the requisite density. It should, when
removed, be compact, and just sink in water, and should perceptibly yield to
the pressure of the fingers. There are perforations in the press blocks, to
firing therein disappears, and a greater proportion of the waste acid is
recovered.
In some cases the acids and water may be supplied by perforated pipes,
lying along the edges of the nitrating vessel, and these edges may, if
desired, be themselves made inclined, like the sides of the troughs f. In the
case of effecting nitration in centrifugals as above, the displacing sulphuric
acid and water may thus be supplied round the edges of the machines, or
removal troughs such as f may be used. It will be obvious that any inert
liquid of suitable specific gravity may be used instead of sulphuric acid, as
a separation layer.
~Moulding.~—By means of the small measuring tank above referred to,
the gun-cotton pulp is drawn off from the stuff chest, and run into moulds
of the shapes and sizes required. Thence a large proportion of the water is
drawn off by means of tubes connected with the vacuum engine, the moulds
having bottoms of fine wire gauze, in order to prevent the pulp from
passing through. Hydraulic pressure of about 34 lbs. on the square inch is
then applied, which has the effect of compressing the pulp into a state in
which it has sufficient consistency to enable it to be handled with care, and
also expels a portion of the remaining water.
~Compressing.~—The moulded gun-cotton is now taken to the press
house, which is situated at some distance from the rest of the factory. Here
the moulds are subjected to powerful hydraulic pressure, from 5 to 6 tons
per square inch, and is compressed to one-third of its previous bulk. The
slabs or discs thus formed are kept under pressure for a short time, not
exceeding a minute and a half, to give the requisite density. It should, when
removed, be compact, and just sink in water, and should perceptibly yield to
the pressure of the fingers. There are perforations in the press blocks, to
Page 87
allow of the escape of gases, if formed, by reason of sufficient heat being
generated. The men working the press are placed under cover, behind strong
rope mantlets having eye tubes which command a view of the press.
~Packing.~—The finished slabs and discs are dipped into a solution of
soda and carbolic acid, and packed in special wood metal-lined cases. When
it is to be sent abroad, the metal lining, which is made of tinned copper, is
soldered down, but both the outer wooden and inner metal cases are fitted
with air-tight screw-plugs, so that when necessary water can be added
without unfastening the cases.
~Reworked gun-cotton~ does not make such good discs as new pulped
gun- cotton, probably because the fibrous tenacity of the gun-cotton has
been destroyed by the amount of pressure it has previously undergone, so
that when repulped it resembles fine dust, and a long time is required to
press it into any prescribed form. It is generally boiled for eight hours to
open up the fibre and remove alkali, then broken up by hand with wooden
mallets, pulped, and then used with fresh gun-cotton in the proportion of 1
to 5 parts.
~Manufacture at Le Bouchet.~—At Le Bouchet gun-cotton was made
thus:—200 grms. of cotton were steeped for an hour in 2 litres of a mixture
of 1 volume concentrated nitric and 2 volumes sulphuric acid. The cotton
was then removed and pressed, whereby 7/10ths of the waste acids was
recovered. After this it was washed for one to one and a half hours in
running water, strongly pressed again; allowed to lie for twenty-four hours
in wood-ash lye; then well washed in running water; pressed, and finally
dried on a wide linen sheet, through which was forced air heated to 60° C.
The average yield from 100 parts of cotton was 165 parts of gun- cotton.
The strong pressings of the gun-cotton, while still impregnated with acids,
caused subsequent washings to be difficult and laborious.
generated. The men working the press are placed under cover, behind strong
rope mantlets having eye tubes which command a view of the press.
~Packing.~—The finished slabs and discs are dipped into a solution of
soda and carbolic acid, and packed in special wood metal-lined cases. When
it is to be sent abroad, the metal lining, which is made of tinned copper, is
soldered down, but both the outer wooden and inner metal cases are fitted
with air-tight screw-plugs, so that when necessary water can be added
without unfastening the cases.
~Reworked gun-cotton~ does not make such good discs as new pulped
gun- cotton, probably because the fibrous tenacity of the gun-cotton has
been destroyed by the amount of pressure it has previously undergone, so
that when repulped it resembles fine dust, and a long time is required to
press it into any prescribed form. It is generally boiled for eight hours to
open up the fibre and remove alkali, then broken up by hand with wooden
mallets, pulped, and then used with fresh gun-cotton in the proportion of 1
to 5 parts.
~Manufacture at Le Bouchet.~—At Le Bouchet gun-cotton was made
thus:—200 grms. of cotton were steeped for an hour in 2 litres of a mixture
of 1 volume concentrated nitric and 2 volumes sulphuric acid. The cotton
was then removed and pressed, whereby 7/10ths of the waste acids was
recovered. After this it was washed for one to one and a half hours in
running water, strongly pressed again; allowed to lie for twenty-four hours
in wood-ash lye; then well washed in running water; pressed, and finally
dried on a wide linen sheet, through which was forced air heated to 60° C.
The average yield from 100 parts of cotton was 165 parts of gun- cotton.
The strong pressings of the gun-cotton, while still impregnated with acids,
caused subsequent washings to be difficult and laborious.
Page 88
~Granulation of Gun-Cotton.~—Gun-cotton is often required in the
granulated form for use either alone or with some form of smokeless
powder. This is done under the patent of Sir Frederick Abel in the following
manner:—The gun-cotton from the poacher is placed in a centrifugal
machine, very similar to the hydro-extractors before mentioned, and used
for wringing out the acids. In this machine it loses water until it only
contains 33 per cent., and is at the same time reduced to a more or less
fibrous state. It is then taken to the granulating room, where it is first passed
through sieves or perforations, which break up the mass into little pieces
like shot. The material is then transferred to a revolving drum made of
wood or stout leather, which is kept constantly revolving for some time.
The material is occasionally sprinkled with water. The drum in turning, of
course, carries the granules partially round with it, but the action of gravity
causes them to descend constantly to the lowest point, and thus to roll over
one another continually. The speed of the drum must not be too rapid. None
of the granules must be carried round by centrifugal force, but it must be
fast enough to carry them some little distance up the side of the drum. After
removal from the drum the granules are dried upon shelves in the drying
house.
Gun-cotton is also dissolved in acetone or acetic ether until it has taken
the form of a jelly. It is then rolled into thin sheets, and when dry cut up into
little squares. In the manufacture of smokeless powders from nitro-
cellulose, nitro-lignine, &c., the various substances are mixed with the gun-
cotton or collodion-cotton before granulating.
~Collodion-Cotton.~—In the manufacture of collodion or soluble cotton
the finer qualities of cotton-waste are used and the acids used in the dipping
tanks are much weaker. The manufacture of collodion-cotton has become of
more importance than gun-cotton, by reason of its use for the manufacture
of the various forms of gelatine, such as gelatine dynamite, gelignite,
granulated form for use either alone or with some form of smokeless
powder. This is done under the patent of Sir Frederick Abel in the following
manner:—The gun-cotton from the poacher is placed in a centrifugal
machine, very similar to the hydro-extractors before mentioned, and used
for wringing out the acids. In this machine it loses water until it only
contains 33 per cent., and is at the same time reduced to a more or less
fibrous state. It is then taken to the granulating room, where it is first passed
through sieves or perforations, which break up the mass into little pieces
like shot. The material is then transferred to a revolving drum made of
wood or stout leather, which is kept constantly revolving for some time.
The material is occasionally sprinkled with water. The drum in turning, of
course, carries the granules partially round with it, but the action of gravity
causes them to descend constantly to the lowest point, and thus to roll over
one another continually. The speed of the drum must not be too rapid. None
of the granules must be carried round by centrifugal force, but it must be
fast enough to carry them some little distance up the side of the drum. After
removal from the drum the granules are dried upon shelves in the drying
house.
Gun-cotton is also dissolved in acetone or acetic ether until it has taken
the form of a jelly. It is then rolled into thin sheets, and when dry cut up into
little squares. In the manufacture of smokeless powders from nitro-
cellulose, nitro-lignine, &c., the various substances are mixed with the gun-
cotton or collodion-cotton before granulating.
~Collodion-Cotton.~—In the manufacture of collodion or soluble cotton
the finer qualities of cotton-waste are used and the acids used in the dipping
tanks are much weaker. The manufacture of collodion-cotton has become of
more importance than gun-cotton, by reason of its use for the manufacture
of the various forms of gelatine, such as gelatine dynamite, gelignite,
Page 89
forcite, &c., and also on account of its extensive use in the manufacture of
many of the smokeless powders. It is also used for the manufacture of
"collodion," which is a solution of collodion-cotton in ether-alcohol; for the
preparation of celluloid, and many other purposes. It is less explosive than
gun-cotton, and consists of the lower nitrates of cellulose. It is soluble in
nitro-glycerine, and in a mixture of 2 parts of ether and 1 of alcohol; also in
acetone, acetic ether, and other solvents. MM. Ménard and Domonte were
the first to prepare a soluble gun- cotton, and its investigation was carried
on by Béchamp, who showed that its properties and composition were
different to those of gun-cotton.
~Manufacture.~—The cotton used is cotton-waste.[A] It is thought by
some that Egyptian cotton is preferable, and especially long fibre varieties.
The strength of the acids used is, however, of more importance than the
quality of the cotton. The percentage composition of the acid mixture which
gives the best results is as follows:—Nitric acid, 23 per cent.; sulphuric
acid, 66 per cent.; and water, 11 per cent; and has a specific gravity of 1.712
(about). It can be made by mixing sulphuric acid of specific gravity 1.84
with nitric acid of specific gravity 1.368 in the proportions of 66 per cent.
and 34 per cent. respectively. (The production of the penta-nitro-cellulose is
aimed at if the collodion-cotton is for use as an explosive.) If the acids are
much weaker than this, or potassium nitrate and sulphuric acid is used, the
lower nitrates will be formed. The product, while being entirely soluble in
ether-alcohol or nitro-glycerine, will have a low nitrogen content, whereas a
material with as high a nitrogen as 12 or 12.6 is to be aimed at.
[Footnote A: Raw cotton is often used.]
The cotton should not be allowed to remain in the dipping tanks for more
than five minutes, and the acid mixture should be kept at a temperature of
28° C. or thereabouts; and the cotton should be removed after a few
many of the smokeless powders. It is also used for the manufacture of
"collodion," which is a solution of collodion-cotton in ether-alcohol; for the
preparation of celluloid, and many other purposes. It is less explosive than
gun-cotton, and consists of the lower nitrates of cellulose. It is soluble in
nitro-glycerine, and in a mixture of 2 parts of ether and 1 of alcohol; also in
acetone, acetic ether, and other solvents. MM. Ménard and Domonte were
the first to prepare a soluble gun- cotton, and its investigation was carried
on by Béchamp, who showed that its properties and composition were
different to those of gun-cotton.
~Manufacture.~—The cotton used is cotton-waste.[A] It is thought by
some that Egyptian cotton is preferable, and especially long fibre varieties.
The strength of the acids used is, however, of more importance than the
quality of the cotton. The percentage composition of the acid mixture which
gives the best results is as follows:—Nitric acid, 23 per cent.; sulphuric
acid, 66 per cent.; and water, 11 per cent; and has a specific gravity of 1.712
(about). It can be made by mixing sulphuric acid of specific gravity 1.84
with nitric acid of specific gravity 1.368 in the proportions of 66 per cent.
and 34 per cent. respectively. (The production of the penta-nitro-cellulose is
aimed at if the collodion-cotton is for use as an explosive.) If the acids are
much weaker than this, or potassium nitrate and sulphuric acid is used, the
lower nitrates will be formed. The product, while being entirely soluble in
ether-alcohol or nitro-glycerine, will have a low nitrogen content, whereas a
material with as high a nitrogen as 12 or 12.6 is to be aimed at.
[Footnote A: Raw cotton is often used.]
The cotton should not be allowed to remain in the dipping tanks for more
than five minutes, and the acid mixture should be kept at a temperature of
28° C. or thereabouts; and the cotton should be removed after a few
Page 90
minutes, and should not be pressed out, as in the case of gun-cotton, but at
once transferred to the pots and allowed to steep for forty-eight hours.
(Some prefer twenty-four hours, but there is more chance in this case of the
product containing non-nitrated cellulose.) When the nitration is complete,
the collodion-cotton is removed from the pots, and treated in exactly the
same manner as described under gun-cotton. The produce should be entirely
soluble in ether-alcohol and nitro-glycerine, and contain as near 12.7 per
cent. of nitrogen as possible. The theoretical nitrogen is for the penta-nitro-
cellulose 12.75 per cent. This will, however, seldom if ever be obtained.
The following are some of the results I have obtained from different
samples:—
Nitrogen.
(1.) (2.) (3.)
German make 11.64 11.48 11.49 per cent.
Stowmarket 12.57 12.60 11.22 "
Walsrode 11.61 12.07 11.99 "
Faversham 12.14 11.70 11.60 "
and the following was the analysis of a sample (No. 1) of German-made
collodion-cotton, which made very good blasting gelatine:—
Soluble cotton (collodion) 99.118 per cent.| Nitrogen = 11.64 per cent.
Gun-cotton 0.642 " |
Non-nitrated cotton 0.240 "
Total ash 0.25 "
It should contain as little non-nitrated or unconverted cotton and as little
gun-cotton as possible, as they are both insoluble in nitro- glycerol. The
quality and composition of any sample of collodion-cotton can be quickly
inferred by determining the percentage of nitrogen by means of the
once transferred to the pots and allowed to steep for forty-eight hours.
(Some prefer twenty-four hours, but there is more chance in this case of the
product containing non-nitrated cellulose.) When the nitration is complete,
the collodion-cotton is removed from the pots, and treated in exactly the
same manner as described under gun-cotton. The produce should be entirely
soluble in ether-alcohol and nitro-glycerine, and contain as near 12.7 per
cent. of nitrogen as possible. The theoretical nitrogen is for the penta-nitro-
cellulose 12.75 per cent. This will, however, seldom if ever be obtained.
The following are some of the results I have obtained from different
samples:—
Nitrogen.
(1.) (2.) (3.)
German make 11.64 11.48 11.49 per cent.
Stowmarket 12.57 12.60 11.22 "
Walsrode 11.61 12.07 11.99 "
Faversham 12.14 11.70 11.60 "
and the following was the analysis of a sample (No. 1) of German-made
collodion-cotton, which made very good blasting gelatine:—
Soluble cotton (collodion) 99.118 per cent.| Nitrogen = 11.64 per cent.
Gun-cotton 0.642 " |
Non-nitrated cotton 0.240 "
Total ash 0.25 "
It should contain as little non-nitrated or unconverted cotton and as little
gun-cotton as possible, as they are both insoluble in nitro- glycerol. The
quality and composition of any sample of collodion-cotton can be quickly
inferred by determining the percentage of nitrogen by means of the
Page 91
nitrometer and the use of the solubility test.[A] A high nitrogen content
coupled with a high solubility is the end to be aimed at; a high nitrogen with
a low solubility shows the presence of gun-cotton, and a low nitrogen,
together with a low solubility, the presence of unnitrated cotton. Where
complete solubility is essential and the percentage of nitrogen less
important, Dr Lunge recommends nitration with a mixture of equal parts of
sulphuric and nitric acids containing from 19 to 20 per cent. of water.
[Footnote A: See Analysis of Explosives.]
Mr T.R. France claims to have invented some improvements in the
manufacture of soluble nitro-cellulose. His object has been to produce an
article as uniform as possible. His explanation of the imperfect action of the
acids is that, however uniform the mixed acids may be in strength and
proportions, and however carefully the operations of nitrating, &c., may be
conducted, there are variable elements found in different samples of cotton.
The cotton fibre has for its protection a glazed surface. It is tubular and
cellular in structure, and contains a natural semi-fluid substance composed
of oil or gum, which varies in nature according to the nature of the soil
upon which the cotton is grown. The tubes of the fibre seem to be open at
one end only when the fibre is of normal length. When, therefore, the cotton
is subjected to the action of the mixed acids, the line of least resistance
seems to be taken by them, viz., the insides of the tubes constituting the
fibre of the cotton, into which they are taken by capillary attraction, and are
subject to change as they progress, and to the increased resistance from the
oil or gum, &c., in their progress, and therefore to modified action, the
result of which is slower and slower action, or chemical change. He also
thinks it is possible that the power of capillary attraction is balanced in the
tubes by air contained therein, after a little, sufficiently so to prevent the
acids from taking full effect. To get over this, Mr France uses his cotton in a
fine state, almost dust, in fact, and then nitrates in the usual mixture of acids
coupled with a high solubility is the end to be aimed at; a high nitrogen with
a low solubility shows the presence of gun-cotton, and a low nitrogen,
together with a low solubility, the presence of unnitrated cotton. Where
complete solubility is essential and the percentage of nitrogen less
important, Dr Lunge recommends nitration with a mixture of equal parts of
sulphuric and nitric acids containing from 19 to 20 per cent. of water.
[Footnote A: See Analysis of Explosives.]
Mr T.R. France claims to have invented some improvements in the
manufacture of soluble nitro-cellulose. His object has been to produce an
article as uniform as possible. His explanation of the imperfect action of the
acids is that, however uniform the mixed acids may be in strength and
proportions, and however carefully the operations of nitrating, &c., may be
conducted, there are variable elements found in different samples of cotton.
The cotton fibre has for its protection a glazed surface. It is tubular and
cellular in structure, and contains a natural semi-fluid substance composed
of oil or gum, which varies in nature according to the nature of the soil
upon which the cotton is grown. The tubes of the fibre seem to be open at
one end only when the fibre is of normal length. When, therefore, the cotton
is subjected to the action of the mixed acids, the line of least resistance
seems to be taken by them, viz., the insides of the tubes constituting the
fibre of the cotton, into which they are taken by capillary attraction, and are
subject to change as they progress, and to the increased resistance from the
oil or gum, &c., in their progress, and therefore to modified action, the
result of which is slower and slower action, or chemical change. He also
thinks it is possible that the power of capillary attraction is balanced in the
tubes by air contained therein, after a little, sufficiently so to prevent the
acids from taking full effect. To get over this, Mr France uses his cotton in a
fine state, almost dust, in fact, and then nitrates in the usual mixture of acids
Page 92
at 40° to 90° F., the excess of acids being removed by pressure. He says he
does not find it necessary to wash this fine cotton dust in an alkaline
solution previous to nitration. His mixed acids consist of 8 parts HNO_{3}
= 42° B., and 12 parts H_{2}SO_{4} = 66° B., and he stirs in the dipping
tank for fifteen minutes, the temperature being 50° F. to 100° F., the
temperature preferred being 75° F.
~"Nitrated" Gun-Cotton.~—The nitrates that are or have been mixed
with gun-cotton in order to supply oxygen are potassium nitrate, ammonium
nitrate, and barium nitrate (tonite). The total combustion of gun-cotton by
potassium nitrate corresponds to the equation:—
10[C_{24}H_{18}(NO_{3}H){11}O{9}] + 82KNO_{3} = 199CO_{2} + 41K_{2}CO_{3} +
145H_{2}O + 96N_{2},
or 828 grms. of nitrate for 1,143 grms. of gun-cotton, or 42 per cent.
nitrate and 58 per cent. gun-cotton. The explosive made at Faversham by
the Cotton Powder Company, and known as tonite No. 1, consists of very
nearly half gun-cotton and half barium nitrate. The relations by weight of
total combustion would be 51.6 of gun-cotton to 48.4 of barium nitrate. The
average composition of tonite I have found by analysis to be 51 per cent.
gun-cotton to 49 per cent. barium nitrate. The heat liberated is practically
the same as for an equivalent weight of KNO_{3}; but the barium nitrate
mixture weighs 2,223 grms. instead of 1,971 grms., or one-eighth more.
The advantage in mixing a nitrate with gun-cotton is that it supplies oxygen,
and by converting all the carbon into carbonic acid, prevents the formation
of the poisonous gas carbonic oxide (CO). The nitrates of potassium and
barium are also used admixed with nitro- cellulose in several of the sporting
smokeless powders.
~The Manufacture of Tonite.~—The explosive tonite was patented by
Messrs Trench, Faure, and Mackie, and is manufactured at Faversham and
does not find it necessary to wash this fine cotton dust in an alkaline
solution previous to nitration. His mixed acids consist of 8 parts HNO_{3}
= 42° B., and 12 parts H_{2}SO_{4} = 66° B., and he stirs in the dipping
tank for fifteen minutes, the temperature being 50° F. to 100° F., the
temperature preferred being 75° F.
~"Nitrated" Gun-Cotton.~—The nitrates that are or have been mixed
with gun-cotton in order to supply oxygen are potassium nitrate, ammonium
nitrate, and barium nitrate (tonite). The total combustion of gun-cotton by
potassium nitrate corresponds to the equation:—
10[C_{24}H_{18}(NO_{3}H){11}O{9}] + 82KNO_{3} = 199CO_{2} + 41K_{2}CO_{3} +
145H_{2}O + 96N_{2},
or 828 grms. of nitrate for 1,143 grms. of gun-cotton, or 42 per cent.
nitrate and 58 per cent. gun-cotton. The explosive made at Faversham by
the Cotton Powder Company, and known as tonite No. 1, consists of very
nearly half gun-cotton and half barium nitrate. The relations by weight of
total combustion would be 51.6 of gun-cotton to 48.4 of barium nitrate. The
average composition of tonite I have found by analysis to be 51 per cent.
gun-cotton to 49 per cent. barium nitrate. The heat liberated is practically
the same as for an equivalent weight of KNO_{3}; but the barium nitrate
mixture weighs 2,223 grms. instead of 1,971 grms., or one-eighth more.
The advantage in mixing a nitrate with gun-cotton is that it supplies oxygen,
and by converting all the carbon into carbonic acid, prevents the formation
of the poisonous gas carbonic oxide (CO). The nitrates of potassium and
barium are also used admixed with nitro- cellulose in several of the sporting
smokeless powders.
~The Manufacture of Tonite.~—The explosive tonite was patented by
Messrs Trench, Faure, and Mackie, and is manufactured at Faversham and
Page 93
Melling at the works of the Cotton Powder Company, and at San Francisco
by the Tonite Powder Company. It consists of finely divided and macerated
gun-cotton incorporated with finely ground nitrate of barium which has
been carefully recrystallised. It is made by acting upon carbonate of
barium[A] with nitric acid. The wet and perfectly purified, finely pulped
gun-cotton is intimately mixed up between edge runners with about the
same weight of nitrate, and the mixing and grinding continued until the
whole has become an intimately mixed paste. This paste is then compressed
into cartridges, formed with a recess at one end for the purpose of inserting
the detonator. The whole is then covered with paraffined paper.
[Footnote A: Witherite, BaCO_{3} + 2HNO_{3} = Ba(NO_{3}){2} +
CO{2} +
H_{2}O.]
The tonite No. 2 consisted of gun-cotton, nitrates of potash and soda,
charcoal and sulphur. Tonite No. 3[A] is composed as follows:—Gun-
cotton, 19 per cent.; di-nitro-benzol, 13 per cent.; and barium nitrate, 68 per
cent. or similar proportions. It is a yellowish colour, and being slower in its
explosive action, is better adapted for blasting soft rock.
[Footnote A: Tonite No. 1 was patented by Messrs Trench, Faure, and
Mackie, and tonite Nos. 2 and 3 by Trench alone.]
Tonite is extensively used in torpedoes and for submarine blasting, also
for quarries, &c. Large quantities were used in the construction of the
Manchester Ship Canal. Among its advantages are, that the English
railways will take tonite on the same footing as gunpowder; it is a very
dense material; if wetted it can easily be dried in the sun; it very readily
explodes by the use of a proper detonator; while it burns very slowly and
without the least danger; the cartridges being waterproofed, it can be
employed in wet bore holes, and it can be tamped with water; and finally, as
by the Tonite Powder Company. It consists of finely divided and macerated
gun-cotton incorporated with finely ground nitrate of barium which has
been carefully recrystallised. It is made by acting upon carbonate of
barium[A] with nitric acid. The wet and perfectly purified, finely pulped
gun-cotton is intimately mixed up between edge runners with about the
same weight of nitrate, and the mixing and grinding continued until the
whole has become an intimately mixed paste. This paste is then compressed
into cartridges, formed with a recess at one end for the purpose of inserting
the detonator. The whole is then covered with paraffined paper.
[Footnote A: Witherite, BaCO_{3} + 2HNO_{3} = Ba(NO_{3}){2} +
CO{2} +
H_{2}O.]
The tonite No. 2 consisted of gun-cotton, nitrates of potash and soda,
charcoal and sulphur. Tonite No. 3[A] is composed as follows:—Gun-
cotton, 19 per cent.; di-nitro-benzol, 13 per cent.; and barium nitrate, 68 per
cent. or similar proportions. It is a yellowish colour, and being slower in its
explosive action, is better adapted for blasting soft rock.
[Footnote A: Tonite No. 1 was patented by Messrs Trench, Faure, and
Mackie, and tonite Nos. 2 and 3 by Trench alone.]
Tonite is extensively used in torpedoes and for submarine blasting, also
for quarries, &c. Large quantities were used in the construction of the
Manchester Ship Canal. Among its advantages are, that the English
railways will take tonite on the same footing as gunpowder; it is a very
dense material; if wetted it can easily be dried in the sun; it very readily
explodes by the use of a proper detonator; while it burns very slowly and
without the least danger; the cartridges being waterproofed, it can be
employed in wet bore holes, and it can be tamped with water; and finally, as
Page 94
it contains sufficient oxygen to oxidise the carbon, no carbonic oxide (CO)
gas is formed, i.e., its detonation is perfect. It is a very safe explosive to use,
being little susceptible to either blows or friction.
Not long ago, a committee, composed of Prof. P. Bedson, Drs Drummond
and Hume, Mr T. Bell, one of H.M. Inspectors of Coal Mines, and others, in
considering the problem whether the fumes produced by the combustion of
tonite were injurious to health, carried out a series of experiments in coal
mines for this purpose. The air at the "intake" was analysed, also the air of
the "return," and the smoky air in the vicinity of the shot holes. The
cartridge was surrounded by the flame-extinguishing mixture, and packed
in a brown paper bag. During the first experiment nineteen shots were fired
(= 6.29 lbs. tonite). The "return" air showed only a trace of carbonic oxide
gas (CO). At the second experiment thirteen shots were fired (= 4.40 lbs.
tonite), and analysis of the air of the "return" showed that CO was present
in traces only, whilst the fumes contained only 1.9 to 4.8 parts per 10,000.
~Dangers in connection with the Manufacture of Guncotton, &c.~—Of
all the nitro compounds, the least dangerous to manufacture are gun-cotton
and collodion-cotton. The fact that the Stowmarket Factory is within five
minutes' walk of the town shows how safe the manufacture of this explosive
is regarded. With the exception of the nitration and the compression into
blocks or discs, the whole process is worked with a large excess of water,
and the probability of an explosion is thus reduced to a minimum. Among
the precautions that should, however, be taken, are—first, the careful
extraction of the resinous and soluble substances from the cotton before
nitration, as it was shown many years ago by Sir F.A. Abel that the
instability of the gun-cotton first manufactured in England and Austria was
chiefly due to these compounds. They are generally removed by boiling the
cotton in a soda solution.
gas is formed, i.e., its detonation is perfect. It is a very safe explosive to use,
being little susceptible to either blows or friction.
Not long ago, a committee, composed of Prof. P. Bedson, Drs Drummond
and Hume, Mr T. Bell, one of H.M. Inspectors of Coal Mines, and others, in
considering the problem whether the fumes produced by the combustion of
tonite were injurious to health, carried out a series of experiments in coal
mines for this purpose. The air at the "intake" was analysed, also the air of
the "return," and the smoky air in the vicinity of the shot holes. The
cartridge was surrounded by the flame-extinguishing mixture, and packed
in a brown paper bag. During the first experiment nineteen shots were fired
(= 6.29 lbs. tonite). The "return" air showed only a trace of carbonic oxide
gas (CO). At the second experiment thirteen shots were fired (= 4.40 lbs.
tonite), and analysis of the air of the "return" showed that CO was present
in traces only, whilst the fumes contained only 1.9 to 4.8 parts per 10,000.
~Dangers in connection with the Manufacture of Guncotton, &c.~—Of
all the nitro compounds, the least dangerous to manufacture are gun-cotton
and collodion-cotton. The fact that the Stowmarket Factory is within five
minutes' walk of the town shows how safe the manufacture of this explosive
is regarded. With the exception of the nitration and the compression into
blocks or discs, the whole process is worked with a large excess of water,
and the probability of an explosion is thus reduced to a minimum. Among
the precautions that should, however, be taken, are—first, the careful
extraction of the resinous and soluble substances from the cotton before
nitration, as it was shown many years ago by Sir F.A. Abel that the
instability of the gun-cotton first manufactured in England and Austria was
chiefly due to these compounds. They are generally removed by boiling the
cotton in a soda solution.
Page 95
The actual nitration of cotton is not a dangerous operation, but the
operations of wringing in the hydro-extractors, and washing the nitro-
cotton after it leaves the first centrifugal machine, are somewhat so. Great
care should be taken that the wrung-out nitro-cotton at once comes in
contact with a large excess of water, i.e., is at once immersed entirely in the
water, since at this stage it is especially liable to decomposition, which,
once started, is very difficult to stop. The warmer the mixture and the less
water it contains, the more liable it is to decomposition; hence it is that on
warm and damp days the centrifugal machines are most likely to fire. The
commencement of decomposition may be at once detected by the evolution
of red fumes. Directly the gun-cotton is immersed in the large quantity of
water in the beater and poacher it is safe.
In order that the final product may be stable and have good keeping
qualities, it is necessary that it should be washed completely free from acid.
The treatment in the beater and poacher, by causing the material to assume
the state of a fine pulp, in contact with a large quantity of water, does a
good deal to get rid of the free acid, but the boiling process is absolutely
necessary. It has been proposed to neutralise the free acid with a dilute
solution of ammonia; and Dr C.O. Weber has published some experiments
bearing upon this treatment. He found that after treatment with ammonia,
pyroxyline assumed a slightly yellowish tinge, which was a sure sign of
alkalinity. It was then removed from the water, and roughly dried between
folds of filter paper, and afterwards dried in an oven at 70° C. After three
hours, however, an explosion took place, which entirely destroyed the
strong copper oven in which the nitro- cotton (about one oz.) had been
drying. The explosion was in some respects remarkable. The pyroxyline
was the di-nitro-cellulose (or possibly the penta-nitro?), and the temperature
was below the igniting point of this material (40° C. would have been a
better temperature). Dr Weber determined the ignition point of his di-nitro-
cellulose, and found it to be 194° to 198° C., and he is therefore of opinion
operations of wringing in the hydro-extractors, and washing the nitro-
cotton after it leaves the first centrifugal machine, are somewhat so. Great
care should be taken that the wrung-out nitro-cotton at once comes in
contact with a large excess of water, i.e., is at once immersed entirely in the
water, since at this stage it is especially liable to decomposition, which,
once started, is very difficult to stop. The warmer the mixture and the less
water it contains, the more liable it is to decomposition; hence it is that on
warm and damp days the centrifugal machines are most likely to fire. The
commencement of decomposition may be at once detected by the evolution
of red fumes. Directly the gun-cotton is immersed in the large quantity of
water in the beater and poacher it is safe.
In order that the final product may be stable and have good keeping
qualities, it is necessary that it should be washed completely free from acid.
The treatment in the beater and poacher, by causing the material to assume
the state of a fine pulp, in contact with a large quantity of water, does a
good deal to get rid of the free acid, but the boiling process is absolutely
necessary. It has been proposed to neutralise the free acid with a dilute
solution of ammonia; and Dr C.O. Weber has published some experiments
bearing upon this treatment. He found that after treatment with ammonia,
pyroxyline assumed a slightly yellowish tinge, which was a sure sign of
alkalinity. It was then removed from the water, and roughly dried between
folds of filter paper, and afterwards dried in an oven at 70° C. After three
hours, however, an explosion took place, which entirely destroyed the
strong copper oven in which the nitro- cotton (about one oz.) had been
drying. The explosion was in some respects remarkable. The pyroxyline
was the di-nitro-cellulose (or possibly the penta-nitro?), and the temperature
was below the igniting point of this material (40° C. would have been a
better temperature). Dr Weber determined the ignition point of his di-nitro-
cellulose, and found it to be 194° to 198° C., and he is therefore of opinion
Page 96
that the explosion was due to the treatment of the partially washed material
with ammonia. A certain quantity of ammonium nitrate was probably
formed, and subsequently dried upon the nitro-cellulose, in a state of very
fine subdivision. The faintest trace of acid would then be sufficient to bring
about the explosive ignition of the ammonium nitrate.
The drying of gun-cotton or collodion-cotton is also a somewhat
dangerous operation. A temperature of 40° C. (104° F.) should not be
exceeded, and thermometers should be placed in the nitro-cotton, and the
temperature frequently observed. An electric alarm thermometer is also a
useful adjunct to the cotton drying house. Great care must also be taken that
there are no exposed hot-water pipes or stoves in the drying house, as the
fine gun-cotton dust produced by the turning or moving of the material
upon the shelves would settle upon such pipes or stoves, and becoming hot,
would be very sensitive to the least friction. The floor also should be
covered with linoleum or indiarubber. When hot currents of air are made to
pass over the surface of gun-cotton, the gun-cotton becomes electrified. It is
important, therefore, to provide some means to carry it away. Mr W.F. Reid,
F.I.C., was the first to use metal frames, carriers, and sieves, upon which is
secured the cloth holding the gun-cotton, and to earth them.
The compression of gun-cotton into blocks, discs, &c., is also attended
with considerable risk. Mr O. Guttmann, in an interesting paper upon "The
Dangers in the Manufacture of Explosives" (Jour. Soc. Chem. Ind., No. 3,
vol. xi., 1892), says: "The compression of gun-cotton into cartridges
requires far more care than that of gunpowder, as this is done in a warm
state, and gun-cotton even when cold, is more sensitive than gunpowder.
When coming out of the centrifugal machines, the gun-cotton should
always pass first through a sieve, in order to detect nails or matches which
may by chance have got into it. What has been said as to gunpowder presses
applies still more to those for gun-cotton, although the latter are always
with ammonia. A certain quantity of ammonium nitrate was probably
formed, and subsequently dried upon the nitro-cellulose, in a state of very
fine subdivision. The faintest trace of acid would then be sufficient to bring
about the explosive ignition of the ammonium nitrate.
The drying of gun-cotton or collodion-cotton is also a somewhat
dangerous operation. A temperature of 40° C. (104° F.) should not be
exceeded, and thermometers should be placed in the nitro-cotton, and the
temperature frequently observed. An electric alarm thermometer is also a
useful adjunct to the cotton drying house. Great care must also be taken that
there are no exposed hot-water pipes or stoves in the drying house, as the
fine gun-cotton dust produced by the turning or moving of the material
upon the shelves would settle upon such pipes or stoves, and becoming hot,
would be very sensitive to the least friction. The floor also should be
covered with linoleum or indiarubber. When hot currents of air are made to
pass over the surface of gun-cotton, the gun-cotton becomes electrified. It is
important, therefore, to provide some means to carry it away. Mr W.F. Reid,
F.I.C., was the first to use metal frames, carriers, and sieves, upon which is
secured the cloth holding the gun-cotton, and to earth them.
The compression of gun-cotton into blocks, discs, &c., is also attended
with considerable risk. Mr O. Guttmann, in an interesting paper upon "The
Dangers in the Manufacture of Explosives" (Jour. Soc. Chem. Ind., No. 3,
vol. xi., 1892), says: "The compression of gun-cotton into cartridges
requires far more care than that of gunpowder, as this is done in a warm
state, and gun-cotton even when cold, is more sensitive than gunpowder.
When coming out of the centrifugal machines, the gun-cotton should
always pass first through a sieve, in order to detect nails or matches which
may by chance have got into it. What has been said as to gunpowder presses
applies still more to those for gun-cotton, although the latter are always
Page 97
hydraulic presses. Generally the pistons fit the mould perfectly, that is to
say, they make aspiration like the piston of a pump. But there is no metal as
yet known which for any length of time will stand the constant friction of
compression, and after some time the mould will be wider in that part
where the greatest compression takes place. The best metal for this purpose
has proved to be a special steel made by Krupp, but this also is only
relatively better; for pistons I prefer hard cast iron. If the position of the
moulds and pistons is not exactly the same in all cases, what the Germans
call 'Ecken' (English 'binding') will take place, viz., the mould will stand
obliquely to the piston, and a dangerous friction will result." "Of course, it
is necessary to protect the man working the hydraulic valves during
compression. At Waltham Abbey they have a curtain made of ship's
hawsers, which is at the same time elastic and resistant." Mr Guttmann has
found that a partition wall 12 inches thick, made of 2-inch planks, and filled
with ground cinders, gives very effective protection. A door in this partition
enables the workman to get to the press, and a conical tube penetrates the
wall, enabling the man to see the whole work from a safe standpoint. The
roof, or one side of the building, should be of glass, so as to give the
explosion a direction.
~Trench's Fire-extinguishing Compound~ is manufactured by the Cotton
Powder Company at Faversham, and is the invention of Mr George Trench,
F.C.S., the manager of the Company. The object of the invention is to
surround the cartridges of tonite, when used in coal mines, with a fire-
extinguishing compound. If a charge of tonite, dynamite, or gelatine
dynamite is put inside a few ounces of this mixture, and then fired, not the
least trace of flame can be observed, and experiments appear to show that
there is no flame at all. The compound consists of sawdust impregnated
with a mixture of alum and chlorides of sodium and ammonia. Fig. 22
shows the manner of placing the tonite cartridge in the paper bag, and
say, they make aspiration like the piston of a pump. But there is no metal as
yet known which for any length of time will stand the constant friction of
compression, and after some time the mould will be wider in that part
where the greatest compression takes place. The best metal for this purpose
has proved to be a special steel made by Krupp, but this also is only
relatively better; for pistons I prefer hard cast iron. If the position of the
moulds and pistons is not exactly the same in all cases, what the Germans
call 'Ecken' (English 'binding') will take place, viz., the mould will stand
obliquely to the piston, and a dangerous friction will result." "Of course, it
is necessary to protect the man working the hydraulic valves during
compression. At Waltham Abbey they have a curtain made of ship's
hawsers, which is at the same time elastic and resistant." Mr Guttmann has
found that a partition wall 12 inches thick, made of 2-inch planks, and filled
with ground cinders, gives very effective protection. A door in this partition
enables the workman to get to the press, and a conical tube penetrates the
wall, enabling the man to see the whole work from a safe standpoint. The
roof, or one side of the building, should be of glass, so as to give the
explosion a direction.
~Trench's Fire-extinguishing Compound~ is manufactured by the Cotton
Powder Company at Faversham, and is the invention of Mr George Trench,
F.C.S., the manager of the Company. The object of the invention is to
surround the cartridges of tonite, when used in coal mines, with a fire-
extinguishing compound. If a charge of tonite, dynamite, or gelatine
dynamite is put inside a few ounces of this mixture, and then fired, not the
least trace of flame can be observed, and experiments appear to show that
there is no flame at all. The compound consists of sawdust impregnated
with a mixture of alum and chlorides of sodium and ammonia. Fig. 22
shows the manner of placing the tonite cartridge in the paper bag, and
Page 98
surrounding it with the fire-extinguishing compound, aa. The attachment of
the fuse and detonator is also shown.
[Illustration: FIG. 22.—TRENCH'S FIRE-EXTINGUISHING
CARTRIDGE.]
The following report (taken from the Faversham News, 22nd Oct. 1887)
of experiments conducted in the presence of several scientific and mining
men will show its value:—"A large wrought-iron tank, of 45 cubic feet
capacity, had been sunk level with the ground in the middle of the yard; to
this tank the gas had been laid on, for a purpose that will be explained later
on. The charges were fired by means of electricity, a small dynamo firing
machine being placed from 30 to 40 yards away from the 'mine.'"
Operations were commenced by the top of the tank being covered over and
plastered down in order to make it air-tight; then a sufficient quantity of
coal gas was placed in it to make it highly inflammable and explosive, the
quantity being ascertained by a meter which had been fixed specially for the
purpose. Whilst the gas was being injected the cartridge was prepared.
The first experiment was to try whether a small charge of tonite—fired
without the patent extinguisher—would ignite the gas. The gas having been
turned on, a miner's lamp was placed in the "tank," but this was
extinguished before the full quantity of gas had gone through the meter.
However, the gas being in, the charge of 1-1/4 oz. tonite was placed in the
"mine," the detonator was connected by means of long wires to the dynamo
machine, and the word was given to "fire." With a tremendous report, and a
flash of fire, the covering of the mine flew in all directions, clearly showing
that the gas had exploded. The next cartridge (a similar charge) was
prepared with the patent compound. First of all a brown paper case of about
2 inches diameter was taken, and one of the tonite cartridges was placed in
the centre of it, the intervening space between the charge and-the case being
the fuse and detonator is also shown.
[Illustration: FIG. 22.—TRENCH'S FIRE-EXTINGUISHING
CARTRIDGE.]
The following report (taken from the Faversham News, 22nd Oct. 1887)
of experiments conducted in the presence of several scientific and mining
men will show its value:—"A large wrought-iron tank, of 45 cubic feet
capacity, had been sunk level with the ground in the middle of the yard; to
this tank the gas had been laid on, for a purpose that will be explained later
on. The charges were fired by means of electricity, a small dynamo firing
machine being placed from 30 to 40 yards away from the 'mine.'"
Operations were commenced by the top of the tank being covered over and
plastered down in order to make it air-tight; then a sufficient quantity of
coal gas was placed in it to make it highly inflammable and explosive, the
quantity being ascertained by a meter which had been fixed specially for the
purpose. Whilst the gas was being injected the cartridge was prepared.
The first experiment was to try whether a small charge of tonite—fired
without the patent extinguisher—would ignite the gas. The gas having been
turned on, a miner's lamp was placed in the "tank," but this was
extinguished before the full quantity of gas had gone through the meter.
However, the gas being in, the charge of 1-1/4 oz. tonite was placed in the
"mine," the detonator was connected by means of long wires to the dynamo
machine, and the word was given to "fire." With a tremendous report, and a
flash of fire, the covering of the mine flew in all directions, clearly showing
that the gas had exploded. The next cartridge (a similar charge) was
prepared with the patent compound. First of all a brown paper case of about
2 inches diameter was taken, and one of the tonite cartridges was placed in
the centre of it, the intervening space between the charge and-the case being
Page 99
packed with the "fire-extinguishing compound." The mine having had
another supply of gas injected, the protected cartridge was placed inside and
fired. The result was astonishing, the explosion not being nearly so loud,
whilst there was not the least flash of fire. "Protected" and "unprotected"
charges were fired at intervals, gas being turned into the tank on each
occasion. Charges of tonite varying from 1 to 6 oz. were also used with the
compound. The report was trifling, whilst no flash could be seen.
~Uses of Collodion-Cotton.~—The collodion or soluble gun-cotton is
used for a variety of purposes. The chief use is, however, for the
manufacture of the various explosive gelatine compounds, of which
blasting gelatine is the type. It is also very extensively used in the
manufacture of smokeless powders, both military and sporting—in fact,
very few of them do not contain it. In some, however, nitro-lignose or
nitrated wood is used instead. This, however, is chemically the same thing,
viz., nitro- cellulose, the cellulose being derived from the wood fibre. It is
more used in this connection than the higher nitrate gun-cotton. Another use
to which it has been applied very extensively, of recent years, is in the
manufacture of "celluloid." It is used in photography for the preparation of
the films on the sensitised plates, and many other purposes. Dissolved in a
solution of two parts ether and one of alcohol, it forms the solution known
as collodion, used for a variety of purposes, such as a varnish, as a paint for
signals; in surgery, for uniting the edges of wounds.
Quite lately, Mr Alfred Nobel, the well-known inventor of dynamite, has
patented the use of nitro-cellulose, hydro- or oxy-cellulose, as an artificial
substitute for indiarubber. For this purpose it is dissolved in a suitable non-
volatile or slightly volatile "solvent," such as nitro- naphthalene, di-nitro-
benzene, nitro-toluene, or its homologues; products are obtained varying
from a gelatinous consistency to the hardness of ebonite. The proportions
will vary from about 20 per cent. of nitro- cellulose in the finished product,
another supply of gas injected, the protected cartridge was placed inside and
fired. The result was astonishing, the explosion not being nearly so loud,
whilst there was not the least flash of fire. "Protected" and "unprotected"
charges were fired at intervals, gas being turned into the tank on each
occasion. Charges of tonite varying from 1 to 6 oz. were also used with the
compound. The report was trifling, whilst no flash could be seen.
~Uses of Collodion-Cotton.~—The collodion or soluble gun-cotton is
used for a variety of purposes. The chief use is, however, for the
manufacture of the various explosive gelatine compounds, of which
blasting gelatine is the type. It is also very extensively used in the
manufacture of smokeless powders, both military and sporting—in fact,
very few of them do not contain it. In some, however, nitro-lignose or
nitrated wood is used instead. This, however, is chemically the same thing,
viz., nitro- cellulose, the cellulose being derived from the wood fibre. It is
more used in this connection than the higher nitrate gun-cotton. Another use
to which it has been applied very extensively, of recent years, is in the
manufacture of "celluloid." It is used in photography for the preparation of
the films on the sensitised plates, and many other purposes. Dissolved in a
solution of two parts ether and one of alcohol, it forms the solution known
as collodion, used for a variety of purposes, such as a varnish, as a paint for
signals; in surgery, for uniting the edges of wounds.
Quite lately, Mr Alfred Nobel, the well-known inventor of dynamite, has
patented the use of nitro-cellulose, hydro- or oxy-cellulose, as an artificial
substitute for indiarubber. For this purpose it is dissolved in a suitable non-
volatile or slightly volatile "solvent," such as nitro- naphthalene, di-nitro-
benzene, nitro-toluene, or its homologues; products are obtained varying
from a gelatinous consistency to the hardness of ebonite. The proportions
will vary from about 20 per cent. of nitro- cellulose in the finished product,
Page 100
forming a soft rubber, to 50 per cent. nitrating celluloid, and the "solvent"
chosen will depend on the use to which the rubber substitute is to be put,
the liquids giving a more elastic substance, whilst mixtures of solids and
liquids may be employed when the product is to be used at high
temperatures. By means of rollers steam heated, the incorporation may be
accomplished without the aid of a volatile liquid, or the nitro-cellulose may
be employed wet, the water being removed after "solution."
It is advisable to use the cellulose nitrated only just enough to render it
suitable, in order to reduce the inflammability of the finished product. Mr
W. Allen, M.P., of Gateshead, proposed to use celluloid for cartridge cases,
and thus to lighten ammunition, and prevent jambing, for the case will be
resolved into gases along with the powder. Extractors will also be done
away with.
~Celluloid~ is an intimate mechanical mixture of pyroxyline (gun-cotton
or collodion-cotton) with camphor, first made by Hyatt, of Newark, U.S.A.,
and obtained by adding the pyroxyline to melted camphor, or by strongly
compressing the two substances together, or by dissolving the constituents
in an appropriate solvent, e.g., alcohol or ether, and evaporating to dryness.
A combination of the two latter methods, i.e., partial solution, with pressure,
is now usually adapted. The pyroxyline employed is generally the tetra- and
penta-nitrated cellulose, the hexa-nitrate (gun-cotton) being but seldom
used on account of its explosive properties.
Care is taken to prevent the formation of the hexa-nitrate by immersing
the cellulose in only moderately strong nitric acid, or in a warm mixture of
nitric and sulphuric acids. The paper, either in small pieces or in sheets, is
immersed for about twenty-five minutes in a mixture of 2 parts of nitric
acid and 5 parts of sulphuric acid, at a temperature of about 30° C., after
which the nitrated cellulose is thoroughly washed with water to remove the
chosen will depend on the use to which the rubber substitute is to be put,
the liquids giving a more elastic substance, whilst mixtures of solids and
liquids may be employed when the product is to be used at high
temperatures. By means of rollers steam heated, the incorporation may be
accomplished without the aid of a volatile liquid, or the nitro-cellulose may
be employed wet, the water being removed after "solution."
It is advisable to use the cellulose nitrated only just enough to render it
suitable, in order to reduce the inflammability of the finished product. Mr
W. Allen, M.P., of Gateshead, proposed to use celluloid for cartridge cases,
and thus to lighten ammunition, and prevent jambing, for the case will be
resolved into gases along with the powder. Extractors will also be done
away with.
~Celluloid~ is an intimate mechanical mixture of pyroxyline (gun-cotton
or collodion-cotton) with camphor, first made by Hyatt, of Newark, U.S.A.,
and obtained by adding the pyroxyline to melted camphor, or by strongly
compressing the two substances together, or by dissolving the constituents
in an appropriate solvent, e.g., alcohol or ether, and evaporating to dryness.
A combination of the two latter methods, i.e., partial solution, with pressure,
is now usually adapted. The pyroxyline employed is generally the tetra- and
penta-nitrated cellulose, the hexa-nitrate (gun-cotton) being but seldom
used on account of its explosive properties.
Care is taken to prevent the formation of the hexa-nitrate by immersing
the cellulose in only moderately strong nitric acid, or in a warm mixture of
nitric and sulphuric acids. The paper, either in small pieces or in sheets, is
immersed for about twenty-five minutes in a mixture of 2 parts of nitric
acid and 5 parts of sulphuric acid, at a temperature of about 30° C., after
which the nitrated cellulose is thoroughly washed with water to remove the
Page 101
last traces of free acid, pressed, and whilst still moist, mixed with the
camphor.
In the process of Trebouillet and De Besancele, the cellulose, which may
be in the form of paper, cotton, or linen, is twice nitrated—first in the acid
mixture employed in a previous operation; and secondly, in a fresh mixture
of 3 parts sulphuric acid of 1.83 specific gravity, and 2 parts concentrated
nitric acid containing nitrous acid. After each nitration the mass is subjected
to pressure, and is then carefully washed with water, to which, at the last, a
small quantity of ammonia or caustic soda is added to remove the final
traces of acid. The impregnation of the pyroxyline with the camphor is
effected in a variety of ways.
The usual proportion of the constituents is 2 parts pyroxyline and 1 part
camphor. In Trebouillet and De Besancele's process, 100 parts of pyroxyline
are intimately mixed with from 40 to 50 parts camphor, and moulded
together by strong pressure in a hot press, and afterwards dried by exposure
to air, desiccated by calcium chloride or sulphuric acid. The usual method
is, however, to dissolve the camphor in the least possible quantity of
alcohol, and sprinkle the solution over the dry pyroxyline, which is then
covered with a second layer of pyroxyline, and the whole again treated with
the camphor solution, the addition of pyroxyline and camphor solution
being repeated alternately until the requisite amount of celluloid mixture is
obtained.
The mass, which sinks together in transparent lumps, is worked for about
an hour between cold iron rollers, and then for the same period between
rollers which can be gently heated by steam. The layer of celluloid
surrounding the rollers is then cut away and again pressed, the resulting
cake, which is now about 1 cm. thick, being cut into plates of about 70 cm.
long and 30 cm. broad. These are placed one above the other, and strongly
camphor.
In the process of Trebouillet and De Besancele, the cellulose, which may
be in the form of paper, cotton, or linen, is twice nitrated—first in the acid
mixture employed in a previous operation; and secondly, in a fresh mixture
of 3 parts sulphuric acid of 1.83 specific gravity, and 2 parts concentrated
nitric acid containing nitrous acid. After each nitration the mass is subjected
to pressure, and is then carefully washed with water, to which, at the last, a
small quantity of ammonia or caustic soda is added to remove the final
traces of acid. The impregnation of the pyroxyline with the camphor is
effected in a variety of ways.
The usual proportion of the constituents is 2 parts pyroxyline and 1 part
camphor. In Trebouillet and De Besancele's process, 100 parts of pyroxyline
are intimately mixed with from 40 to 50 parts camphor, and moulded
together by strong pressure in a hot press, and afterwards dried by exposure
to air, desiccated by calcium chloride or sulphuric acid. The usual method
is, however, to dissolve the camphor in the least possible quantity of
alcohol, and sprinkle the solution over the dry pyroxyline, which is then
covered with a second layer of pyroxyline, and the whole again treated with
the camphor solution, the addition of pyroxyline and camphor solution
being repeated alternately until the requisite amount of celluloid mixture is
obtained.
The mass, which sinks together in transparent lumps, is worked for about
an hour between cold iron rollers, and then for the same period between
rollers which can be gently heated by steam. The layer of celluloid
surrounding the rollers is then cut away and again pressed, the resulting
cake, which is now about 1 cm. thick, being cut into plates of about 70 cm.
long and 30 cm. broad. These are placed one above the other, and strongly
Page 102
pressed together by hydraulic pressure at a temperature of about 70° for
twenty-four hours. The thick cakes are once more cut into plates of the
desired thickness, and placed in a chamber heated from 30° to 40° for eight
to fourteen days, whereby they become thoroughly dry, and are readily
made into various articles either by being moulded while warm under
pressure, cut, or turned. Occasionally other liquids, e.g., ether and wood
spirit, are used in place of alcohol as solvents for the camphor.
Celluloid readily colours, and can be marbled for manufacturing
purposes, &c. It is highly inflammable and not explosive even under
pressure, and may be worked under the hammer or between rollers without
risk. It softens in boiling water, and may be moulded or pressed. Its specific
gravity varies slightly with its composition and with the degree of pressure
it has received. It is usually 1.35. It appears to be merely a mixture of its
components, since by treatment with appropriate solvents the camphor may
be readily extracted, and on heating the pyroxyline burns away while the
camphor volatilises.
The manufacture of pyroxyline for the purpose of making celluloid has
very much increased during recent years, and with this increase of
production improved methods of manufacture have been invented. A series
of interesting papers upon the manufacture of pyroxyline has been
published by Mr Walter D. Field, of New York, in the Journal of the
American Chemical Society[A] from which the following particulars are
taken:—
[Footnote A: Vol. xv., No. 3, 1893; Vol. xvi., No. 7, 1894; Vol. xvi., No.
8, 1894. Figs. 19, 20, 21, 22, and 23 are taken from Mr Field's paper.]
~Selection of the Fibre.~—Cotton fibre, wood fibre, and flax fibre in the
form of raw cotton, scoured cotton, paper, and rags are most generally used,
and give the best results. As the fibres differ greatly in their structure, they
twenty-four hours. The thick cakes are once more cut into plates of the
desired thickness, and placed in a chamber heated from 30° to 40° for eight
to fourteen days, whereby they become thoroughly dry, and are readily
made into various articles either by being moulded while warm under
pressure, cut, or turned. Occasionally other liquids, e.g., ether and wood
spirit, are used in place of alcohol as solvents for the camphor.
Celluloid readily colours, and can be marbled for manufacturing
purposes, &c. It is highly inflammable and not explosive even under
pressure, and may be worked under the hammer or between rollers without
risk. It softens in boiling water, and may be moulded or pressed. Its specific
gravity varies slightly with its composition and with the degree of pressure
it has received. It is usually 1.35. It appears to be merely a mixture of its
components, since by treatment with appropriate solvents the camphor may
be readily extracted, and on heating the pyroxyline burns away while the
camphor volatilises.
The manufacture of pyroxyline for the purpose of making celluloid has
very much increased during recent years, and with this increase of
production improved methods of manufacture have been invented. A series
of interesting papers upon the manufacture of pyroxyline has been
published by Mr Walter D. Field, of New York, in the Journal of the
American Chemical Society[A] from which the following particulars are
taken:—
[Footnote A: Vol. xv., No. 3, 1893; Vol. xvi., No. 7, 1894; Vol. xvi., No.
8, 1894. Figs. 19, 20, 21, 22, and 23 are taken from Mr Field's paper.]
~Selection of the Fibre.~—Cotton fibre, wood fibre, and flax fibre in the
form of raw cotton, scoured cotton, paper, and rags are most generally used,
and give the best results. As the fibres differ greatly in their structure, they
Page 103
require different methods of nitrating. The cotton fibre is a flattened hollow
ribbon or collapsed cylindrical tube, twisted a number of times, and closed
at one end to form a point. The central canal is large, and runs nearly to the
apex of the fibre. Its side walls are membraneous, and are readily penetrated
by the mixed acids, and consequently the highest nitration results. In the
flax fibre the walls are comparatively thick, the central canal small; hence it
is to be presumed that the nitration must proceed more slowly than in the
case of cotton. The New Zealand flax gives the most perfectly soluble
nitrates of any of the flaxes. Cotton gives a glutinous collodion, and calico a
fluid collodion. One of the largest manufacturers of pyroxyline in the States
uses the "Memphis Star" brand of cotton. This is an upland cotton, and its
fibres are very soft, moist, and elastic. Its colour is light creamy white, and
is retained after nitration. The staple is short, and the twist inferior to other
grades, the straight ribbon-like filaments being quite numerous. This cotton
is used carded, but not scoured. This brand of cotton contains a large
quantity of half and three-quarter ripe fibre, which is extremely thin and
transparent, distributed throughout the bulk of the cotton (Monie., Cotton
Fibre, 67). Mr Field says, "This is a significant fact when it is known that
from this cotton an extremely soluble pyroxyline can be produced."
Pyroxyline of an inferior grade as regards colour only can be produced
from the cotton wastes of the trade. They must be scoured before they are
fit for nitrating. Paper made from the pulps of sulphite and sulphate
processes is capable of yielding a very soluble pyroxyline. It can be nitrated
at high temperatures and still yield good results. Tissue paper made from
flax fibre is also used after being cut into squares.
Mowbray (U.S.P., No. 443, 105, 3rd December 1890) says that a pure
cotton tissue paper less than 1/500 inch in thickness, thin as it is, takes on a
glutinous or colloid surface, and thus requires some thirty minutes to enable
the nitration to take place. With a thicker paper only the surface would be
ribbon or collapsed cylindrical tube, twisted a number of times, and closed
at one end to form a point. The central canal is large, and runs nearly to the
apex of the fibre. Its side walls are membraneous, and are readily penetrated
by the mixed acids, and consequently the highest nitration results. In the
flax fibre the walls are comparatively thick, the central canal small; hence it
is to be presumed that the nitration must proceed more slowly than in the
case of cotton. The New Zealand flax gives the most perfectly soluble
nitrates of any of the flaxes. Cotton gives a glutinous collodion, and calico a
fluid collodion. One of the largest manufacturers of pyroxyline in the States
uses the "Memphis Star" brand of cotton. This is an upland cotton, and its
fibres are very soft, moist, and elastic. Its colour is light creamy white, and
is retained after nitration. The staple is short, and the twist inferior to other
grades, the straight ribbon-like filaments being quite numerous. This cotton
is used carded, but not scoured. This brand of cotton contains a large
quantity of half and three-quarter ripe fibre, which is extremely thin and
transparent, distributed throughout the bulk of the cotton (Monie., Cotton
Fibre, 67). Mr Field says, "This is a significant fact when it is known that
from this cotton an extremely soluble pyroxyline can be produced."
Pyroxyline of an inferior grade as regards colour only can be produced
from the cotton wastes of the trade. They must be scoured before they are
fit for nitrating. Paper made from the pulps of sulphite and sulphate
processes is capable of yielding a very soluble pyroxyline. It can be nitrated
at high temperatures and still yield good results. Tissue paper made from
flax fibre is also used after being cut into squares.
Mowbray (U.S.P., No. 443, 105, 3rd December 1890) says that a pure
cotton tissue paper less than 1/500 inch in thickness, thin as it is, takes on a
glutinous or colloid surface, and thus requires some thirty minutes to enable
the nitration to take place. With a thicker paper only the surface would be
Page 104
nitrated. He therefore uses a fibre that has been saturated with a solution of
nitrate of soda, and afterwards dried slowly, claiming that the salt
crystallises in the fibre, or enters by the action termed osmose, and opens up
the fibre to the action of the acid. This process would only be useful when
the cotton is to be nitrated at a low temperature. At a high temperature it
would be unnecessary.
Dietz and Wayne (U.S.P., No. 133, 969) use ramie, rheca, or China grass
for producing a soluble pyroxyline. That made from ramie is always of
uniform strength and solubility, and requires a smaller quantity of solvent to
dissolve it than that made from cotton. Mr Field's experience, however, is
entirely contrary to this statement. Such is the influence of the physical
form of the fibre on the process of nitration, that when flax fibre and cotton
fibre are nitrated with acid mixtures of exactly the same strength, and at the
same temperature, the solution of the first is glutinous or thick, and the
second fluid or thin. By simply nitrating at a higher temperature than the
cotton, the flax will yield a pyroxyline giving an equally fluid collodion.
The presence of chlorine in the fibre must be carefully avoided, as such a
fibre will yield an acid product which cannot be washed neutral. The fibre
must be dry before nitration; and this is best done, according to Mr Field,
by using the form of drier used in drying wool.
~Nitration of the Fibre.~—Mixed cotton and flax fibre in the form of
paper, from 2/1000 to 3/1000 inch thick, and cut into 1-inch squares, is
nitrated by the Celluloid Manufacturing Company, and the same paper, left
in long strips, 1 inch wide, is used for nitration by the Xylonite
Manufacturing Company, of North Adams, Mass. (U.S.A.).
The Celluloid Company introduce the cut paper into the mixed acids by
means of a hollow, rapidly revolving tube, flared at the lower end, and
immersed in the mixed acids. The centrifugal force of the revolving tube
nitrate of soda, and afterwards dried slowly, claiming that the salt
crystallises in the fibre, or enters by the action termed osmose, and opens up
the fibre to the action of the acid. This process would only be useful when
the cotton is to be nitrated at a low temperature. At a high temperature it
would be unnecessary.
Dietz and Wayne (U.S.P., No. 133, 969) use ramie, rheca, or China grass
for producing a soluble pyroxyline. That made from ramie is always of
uniform strength and solubility, and requires a smaller quantity of solvent to
dissolve it than that made from cotton. Mr Field's experience, however, is
entirely contrary to this statement. Such is the influence of the physical
form of the fibre on the process of nitration, that when flax fibre and cotton
fibre are nitrated with acid mixtures of exactly the same strength, and at the
same temperature, the solution of the first is glutinous or thick, and the
second fluid or thin. By simply nitrating at a higher temperature than the
cotton, the flax will yield a pyroxyline giving an equally fluid collodion.
The presence of chlorine in the fibre must be carefully avoided, as such a
fibre will yield an acid product which cannot be washed neutral. The fibre
must be dry before nitration; and this is best done, according to Mr Field,
by using the form of drier used in drying wool.
~Nitration of the Fibre.~—Mixed cotton and flax fibre in the form of
paper, from 2/1000 to 3/1000 inch thick, and cut into 1-inch squares, is
nitrated by the Celluloid Manufacturing Company, and the same paper, left
in long strips, 1 inch wide, is used for nitration by the Xylonite
Manufacturing Company, of North Adams, Mass. (U.S.A.).
The Celluloid Company introduce the cut paper into the mixed acids by
means of a hollow, rapidly revolving tube, flared at the lower end, and
immersed in the mixed acids. The centrifugal force of the revolving tube
Page 105
throws the paper towards the sides of the vessel, leaving the centre of the
vessel ready for fresh paper.
The Xylonite Company simply cut the paper into long strips, and
introduce it into the mixed acids by means of forks. The arrangement used
by this Company for holding the mixed acids is a cylindrical vessel divided
into a number of sections, the whole revolving like a turntable, thus
allowing the workman to nitrate successively each lot of paper at a given
point. This Company did not remove the acid from the paper after its
immersion, but plunged it immediately into the water, thus losing a large
proportion of the waste acid. The Celluloid Company, by using the paper in
smaller pieces, and more paper to a pound of acid, and wringing the mixed
acid from the paper before immersion in water, had a better process of
nitration.
Other manufacturers use earthenware vessels, and glass or steel rods,
hooked at one end, having small pieces of rubber hose pulled over the other
end to prevent the hand from slipping. The form of vessel in general use is
that given in Fig. 23. It is large enough to nitrate 1 lb. of cotton at a time.
The hook at one end of the rod enables the workman to pull the pyroxyline
apart, and thus ensures saturation of the fibre. In the winter the room in
which the nitrating is done must be kept at a temperature of about 70° F. in
order to secure equality in the batches.
[Illustration: FIG. 23.—VESSEL FOR NITRATING COTTON OR
PAPER.]
The nitrating apparatus of White and Schupphaus (U.S.P., No. 418, 237,
89) Mr Field considers to be both novel and excellent. The cage (Fig. 24),
with its central perforated cylinder (Fig. 25), is intended to ensure the rapid
and perfect saturation of the tissue paper used for nitrating. The patentees
say that no stirring is required with their apparatus. This, says Mr Field,
vessel ready for fresh paper.
The Xylonite Company simply cut the paper into long strips, and
introduce it into the mixed acids by means of forks. The arrangement used
by this Company for holding the mixed acids is a cylindrical vessel divided
into a number of sections, the whole revolving like a turntable, thus
allowing the workman to nitrate successively each lot of paper at a given
point. This Company did not remove the acid from the paper after its
immersion, but plunged it immediately into the water, thus losing a large
proportion of the waste acid. The Celluloid Company, by using the paper in
smaller pieces, and more paper to a pound of acid, and wringing the mixed
acid from the paper before immersion in water, had a better process of
nitration.
Other manufacturers use earthenware vessels, and glass or steel rods,
hooked at one end, having small pieces of rubber hose pulled over the other
end to prevent the hand from slipping. The form of vessel in general use is
that given in Fig. 23. It is large enough to nitrate 1 lb. of cotton at a time.
The hook at one end of the rod enables the workman to pull the pyroxyline
apart, and thus ensures saturation of the fibre. In the winter the room in
which the nitrating is done must be kept at a temperature of about 70° F. in
order to secure equality in the batches.
[Illustration: FIG. 23.—VESSEL FOR NITRATING COTTON OR
PAPER.]
The nitrating apparatus of White and Schupphaus (U.S.P., No. 418, 237,
89) Mr Field considers to be both novel and excellent. The cage (Fig. 24),
with its central perforated cylinder (Fig. 25), is intended to ensure the rapid
and perfect saturation of the tissue paper used for nitrating. The patentees
say that no stirring is required with their apparatus. This, says Mr Field,
Page 106
might be true when paper is used, or even cotton, when the temperature of
nitration is from 30° to 35° C., but would not be true if the temperature
were raised to 50° to 55° C. The process is as follows:— The paper is
nitrated in the cage (Fig. 25), the bottom of which is formed by the flanged
plate C, fastened to the bottom of the internal cylinder B. After nitration the
cage is carried to a wringer, which forms the basket, and the acids removed.
Finally, the cage is taken to a plunge tank, where the paper is removed from
the cage by simply pulling out the central perforated cylinder B. Fig. 26
shows the nitrating pot, with its automatic cover. The plunge tank is shown
in plan and section in Figs. 28 and 29. This apparatus is suitable for the
nitration of cotton fibre in bulk at high or low temperatures. Other methods
that have been patented are Mowbray's (U.S.P., No. 434, 287), in which it is
proposed to nitrate paper in continuous lengths, and Hyatt's (U.S.P., No.
210, 611).
[Illustration: FIG. 24.—CENTRAL PERFORATED CYLINDER.]
[Illustration: FIG. 25.—THE CAGE. WHITE AND SCHUPPHAUS'
NITRATING
APPARATUS.]
[Illustration: FIG. 26.—CELLULOID NITRATING POT.]
[Illustration: FIG. 27.—ANOTHER VIEW.]
[Illustration: FIGS. 28, 29.—PLUNGE TANK, IN PLAN AND
SECTION.]
~The Acid Mixture.~—Various formulæ have been published for
producing soluble nitro-cellulose. In many instances, although the
observations were correct for the single experiment, a dozen experiments
would have produced a dozen different products. The composition of the
nitration is from 30° to 35° C., but would not be true if the temperature
were raised to 50° to 55° C. The process is as follows:— The paper is
nitrated in the cage (Fig. 25), the bottom of which is formed by the flanged
plate C, fastened to the bottom of the internal cylinder B. After nitration the
cage is carried to a wringer, which forms the basket, and the acids removed.
Finally, the cage is taken to a plunge tank, where the paper is removed from
the cage by simply pulling out the central perforated cylinder B. Fig. 26
shows the nitrating pot, with its automatic cover. The plunge tank is shown
in plan and section in Figs. 28 and 29. This apparatus is suitable for the
nitration of cotton fibre in bulk at high or low temperatures. Other methods
that have been patented are Mowbray's (U.S.P., No. 434, 287), in which it is
proposed to nitrate paper in continuous lengths, and Hyatt's (U.S.P., No.
210, 611).
[Illustration: FIG. 24.—CENTRAL PERFORATED CYLINDER.]
[Illustration: FIG. 25.—THE CAGE. WHITE AND SCHUPPHAUS'
NITRATING
APPARATUS.]
[Illustration: FIG. 26.—CELLULOID NITRATING POT.]
[Illustration: FIG. 27.—ANOTHER VIEW.]
[Illustration: FIGS. 28, 29.—PLUNGE TANK, IN PLAN AND
SECTION.]
~The Acid Mixture.~—Various formulæ have been published for
producing soluble nitro-cellulose. In many instances, although the
observations were correct for the single experiment, a dozen experiments
would have produced a dozen different products. The composition of the
Page 107
acids used depends upon the substance to be nitrated, and the temperature at
which the nitration will be worked. Practically there are three formulæ in
general use—the one used by the celluloid manufacturers; another in which
the cotton is nitrated at high temperatures; and a third in which the
temperature of the immersion is low, and the time of nitration about six
hours. Of the three, the best method is the last one, or the one in which the
cotton is immersed at a low temperature, and then the reaction allowed to
proceed in pots holding from 5 to 10 lbs. of cotton. The formula used by the
celluloid manufacturers for the production of the low form of nitrated
product which they use is:—
Sulphuric acid 66 parts by weight.
Nitric acid 17 " "
Water 17 " "
Temperature of immersion, 30° C. Time, twenty to thirty minutes.
The cellulose is used in the form of tissue paper 2/1000 inch thick, 1 lb.
to 100 of acid mixture. The nitro-cellulose produced by this formula is very
insoluble in the compound ethers and other solvents of pyroxyline, and is
seemingly only converted or gelatinised by the action of the solvent. The
next formula produces a mixture of tetra-and penta-nitro- celluloses hardly
soluble in methyl-alcohol (free from acetone), but very soluble in
anhydrous compound ethers, ketones, and aldehydes:—
Nitric acid, sp. gr. 1.435 8 lbs.
Sulphuric acid, sp. gr. 1.83 15-3/4 lbs.
Cotton 14 oz.
Temperature of nitration, 60° C. Time of immersion, forty-five minutes.
which the nitration will be worked. Practically there are three formulæ in
general use—the one used by the celluloid manufacturers; another in which
the cotton is nitrated at high temperatures; and a third in which the
temperature of the immersion is low, and the time of nitration about six
hours. Of the three, the best method is the last one, or the one in which the
cotton is immersed at a low temperature, and then the reaction allowed to
proceed in pots holding from 5 to 10 lbs. of cotton. The formula used by the
celluloid manufacturers for the production of the low form of nitrated
product which they use is:—
Sulphuric acid 66 parts by weight.
Nitric acid 17 " "
Water 17 " "
Temperature of immersion, 30° C. Time, twenty to thirty minutes.
The cellulose is used in the form of tissue paper 2/1000 inch thick, 1 lb.
to 100 of acid mixture. The nitro-cellulose produced by this formula is very
insoluble in the compound ethers and other solvents of pyroxyline, and is
seemingly only converted or gelatinised by the action of the solvent. The
next formula produces a mixture of tetra-and penta-nitro- celluloses hardly
soluble in methyl-alcohol (free from acetone), but very soluble in
anhydrous compound ethers, ketones, and aldehydes:—
Nitric acid, sp. gr. 1.435 8 lbs.
Sulphuric acid, sp. gr. 1.83 15-3/4 lbs.
Cotton 14 oz.
Temperature of nitration, 60° C. Time of immersion, forty-five minutes.
Page 108
The 60° of temperature is developed by mixing the acids together. The
cotton is allowed to remain in the acid until it feels "short" to the rod.
The following table, due to Mr W.D. Field, shows very plainly the great
variation in the time of the immersion and the temperature by seemingly
very slight causes. It extends over fourteen working days, during which
time it rained four days. The formula used is that given above, except that
the specific gravity of the nitric acid is somewhat lower. The product
obtained differs only from that produced by using nitric acid of specific
gravity 1.43 in being soluble in methyl-alcohol. From 30 to 35 lbs. of
pyroxyline were produced in each of the fourteen days.
A careful examination of this table will prove very instructive. The
increase in yield varies from 31 per cent. to nothing, and the loss runs as
high as 10 per cent., yet care was taken to make the product uniform in
quality. On the days it rained there was a loss, with the exception of the
fourth day, when there was neither a loss nor a gain. On the days it was
partly clear, as just before or after rain, the table shows a loss in product.
We can explain this fact by reason of the moisture-absorbing qualities of the
cotton. On the rainy days it would absorb the moisture from the air until,
when immersed in the acids, they were weakened, and the fibre dissolved
more or less in weakened acid, producing what is known as "burning" in the
batch. It will also be noticed that on days which show a loss, the time of the
immersion was correspondingly short, as on the a loss, the time of the
immersion was correspondingly short, as on the tenth, twelfth, and seventh
days.
___________________________________________________________
___________ | | | | | | Specific Gravity. | Time. | |
|_____________________|_______________________________| | | | | | | | |
| |H_{2}S0_{4}.|HNO_{3}.|Hours.|Minutes.|Hours.|Minutes.|
cotton is allowed to remain in the acid until it feels "short" to the rod.
The following table, due to Mr W.D. Field, shows very plainly the great
variation in the time of the immersion and the temperature by seemingly
very slight causes. It extends over fourteen working days, during which
time it rained four days. The formula used is that given above, except that
the specific gravity of the nitric acid is somewhat lower. The product
obtained differs only from that produced by using nitric acid of specific
gravity 1.43 in being soluble in methyl-alcohol. From 30 to 35 lbs. of
pyroxyline were produced in each of the fourteen days.
A careful examination of this table will prove very instructive. The
increase in yield varies from 31 per cent. to nothing, and the loss runs as
high as 10 per cent., yet care was taken to make the product uniform in
quality. On the days it rained there was a loss, with the exception of the
fourth day, when there was neither a loss nor a gain. On the days it was
partly clear, as just before or after rain, the table shows a loss in product.
We can explain this fact by reason of the moisture-absorbing qualities of the
cotton. On the rainy days it would absorb the moisture from the air until,
when immersed in the acids, they were weakened, and the fibre dissolved
more or less in weakened acid, producing what is known as "burning" in the
batch. It will also be noticed that on days which show a loss, the time of the
immersion was correspondingly short, as on the a loss, the time of the
immersion was correspondingly short, as on the tenth, twelfth, and seventh
days.
___________________________________________________________
___________ | | | | | | Specific Gravity. | Time. | |
|_____________________|_______________________________| | | | | | | | |
| |H_{2}S0_{4}.|HNO_{3}.|Hours.|Minutes.|Hours.|Minutes.|
Page 109
|________________|____________|________|______|________|______|__
______| | | | | | | | | | 1. Clear | 1.838 | 1.4249 | … | 20 | 4 | … | | 2. " | 1.837 |
1.4249 | … | 20 | 2 | … | | 3. Cloudy | 1.837 | 1.4226 | … | 45 | 2 | … | | 4.
Rain | 1.837 | 1.420 | … | 20 | 1 | 20 | | 5. Clear | 1.8377 | 1.42 | 1 | 15 | 2 | …
| | 6. Rainy | 1.8391 | 1.422 | … | 35 | 1 | 40 | | 7. Cloudy | 1.835 | 1.4226 | …
| 20 | … | 35 | | 8. Clear | 1.835 | 1.422 | … | 35 | 1 | 10 | | 9. Partly Clear|
1.824 | 1.4271 | … | 20 | 1 | … | |10. " | 1.83 | 1.4271 | … | 10 | … | 25 | |11.
Cloudy | 1.832 | 1.425 | … | 10 | … | 50 | |12. Rainy | 1.822 | 1.425 | … | 10 |
… | 20 | |13. Partly CLear| 1.8378 | 1.4257 | … | 60 | 1 | 40 | |14. Cloudy |
1.837 | 1.4257 | 1 | 56 | 4 | 40 |
|________________|____________|________|______|________|______|__
______| | | | | | |Temp., Deg. C. | Percentage | |
|_______________|___________________| | | | | | | | | From | To | Increase. |
Loss. | |________________|_______|_______|___________|_______| | | | | |
| | 1. Clear | 57° | 62° | 31 | … | | 2. " | 60° | 62° | 18 | … | | 3. Cloudy | 60° |
62° | 7 | … | | 4. Rain | 60° | 63° | 0 | 0 | | 5. Clear | 58° | 62° | 15 | … | | 6.
Rainy | 58° | 62° | … | 2 | | 7. Cloudy | 62° | 65° | … | 10 | | 8. Clear | 60° |
62° | 5 | … | | 9. Partly Clear| 50° | 60° | … | 3 | |10. " | 58° | 60° | … | 10 |
|11. Cloudy | 58° | 60° | 8 | … | |12. Rainy | 58° | 60° | … | 10 | |13. Partly
CLear| 50° | 58° | 20 | … | |14. Cloudy | 50° | 60° | 16 | … |
|________________|_______|_______|___________|_______|
The lesson this table teaches is, that it is almost impossible to nitrate
cellulose in small quantities, and get uniform results, when the nitration is
carried on at high temperatures. As regards the solubility of pyroxyline,
Parks found that nitro-benzene, aniline, glacial acetic acid, and camphor,
dissolved in the more volatile solvents methyl-alcohol and alcohol-ether,
were much the best solvents for producing a plastic, as they are less
volatile, and develop greater solvent action under the influence of heat.
Nitro-benzene gives a solution that is granular; it seems to merely convert
the pyroxyline, and not to dissolve it; but on the addition of alcohol, a
______| | | | | | | | | | 1. Clear | 1.838 | 1.4249 | … | 20 | 4 | … | | 2. " | 1.837 |
1.4249 | … | 20 | 2 | … | | 3. Cloudy | 1.837 | 1.4226 | … | 45 | 2 | … | | 4.
Rain | 1.837 | 1.420 | … | 20 | 1 | 20 | | 5. Clear | 1.8377 | 1.42 | 1 | 15 | 2 | …
| | 6. Rainy | 1.8391 | 1.422 | … | 35 | 1 | 40 | | 7. Cloudy | 1.835 | 1.4226 | …
| 20 | … | 35 | | 8. Clear | 1.835 | 1.422 | … | 35 | 1 | 10 | | 9. Partly Clear|
1.824 | 1.4271 | … | 20 | 1 | … | |10. " | 1.83 | 1.4271 | … | 10 | … | 25 | |11.
Cloudy | 1.832 | 1.425 | … | 10 | … | 50 | |12. Rainy | 1.822 | 1.425 | … | 10 |
… | 20 | |13. Partly CLear| 1.8378 | 1.4257 | … | 60 | 1 | 40 | |14. Cloudy |
1.837 | 1.4257 | 1 | 56 | 4 | 40 |
|________________|____________|________|______|________|______|__
______| | | | | | |Temp., Deg. C. | Percentage | |
|_______________|___________________| | | | | | | | | From | To | Increase. |
Loss. | |________________|_______|_______|___________|_______| | | | | |
| | 1. Clear | 57° | 62° | 31 | … | | 2. " | 60° | 62° | 18 | … | | 3. Cloudy | 60° |
62° | 7 | … | | 4. Rain | 60° | 63° | 0 | 0 | | 5. Clear | 58° | 62° | 15 | … | | 6.
Rainy | 58° | 62° | … | 2 | | 7. Cloudy | 62° | 65° | … | 10 | | 8. Clear | 60° |
62° | 5 | … | | 9. Partly Clear| 50° | 60° | … | 3 | |10. " | 58° | 60° | … | 10 |
|11. Cloudy | 58° | 60° | 8 | … | |12. Rainy | 58° | 60° | … | 10 | |13. Partly
CLear| 50° | 58° | 20 | … | |14. Cloudy | 50° | 60° | 16 | … |
|________________|_______|_______|___________|_______|
The lesson this table teaches is, that it is almost impossible to nitrate
cellulose in small quantities, and get uniform results, when the nitration is
carried on at high temperatures. As regards the solubility of pyroxyline,
Parks found that nitro-benzene, aniline, glacial acetic acid, and camphor,
dissolved in the more volatile solvents methyl-alcohol and alcohol-ether,
were much the best solvents for producing a plastic, as they are less
volatile, and develop greater solvent action under the influence of heat.
Nitro-benzene gives a solution that is granular; it seems to merely convert
the pyroxyline, and not to dissolve it; but on the addition of alcohol, a
Page 110
solution is at once obtained, and the granular appearance disappears, and
the solution becomes homogeneous. The acid mixture and the method of
nitrating have much to do with the action of the various solvents, so also
has the presence of water.
Dr Schupphaus found that propyl and isobutyl alcohols with camphor
were active solvents, and the ketones, palmitone, and stearone in alcohol
solution, also alpha- and beta-naphthol, with alcohol and anthraquinone
(diphenylene diketone) in alcoholic solution, and also iso-valeric aldehyde
and its derivatives, amyliden-dimethyl and amyliden-diethyl ethers.
August Sayer (U.S.P., No. 470,451) finds diethyl-ketone, dibutyl-ketone,
di-pentyl-ketone, and the mixed ketones,[A] methyl-ethyl, methyl-propyl,
methyl-butyl, methyl-amyl, and ethyl-butyl ketones are active solvents of
pyroxyline; and Paget finds that although methyl-amyl oxide is a solvent,
that ethyl-amyl oxide is not.
[Footnote A: Ketones are derived from the fatty acids by the substitution
of the hydroxyl of the latter by a monad positive radical. They thus
resemble aldehydes in constitution. The best-known ketone is acetone
CH_{3}CO.CH_{3}. Mixed ketones are obtained by distilling together salts
of two different fatty acids. Thus potassic butyrate and potassic acetate form
propyl-methyl-ketone—
C(C_{2}H_{5})H_{2}
|
CO.CH_{3}]
The solvents of pyroxyline can be divided into general classes—First,
those which are solvents without the aid of heat or solution in alcohol;
second, those that are solvents when dissolved in alcohol. These solvents
the solution becomes homogeneous. The acid mixture and the method of
nitrating have much to do with the action of the various solvents, so also
has the presence of water.
Dr Schupphaus found that propyl and isobutyl alcohols with camphor
were active solvents, and the ketones, palmitone, and stearone in alcohol
solution, also alpha- and beta-naphthol, with alcohol and anthraquinone
(diphenylene diketone) in alcoholic solution, and also iso-valeric aldehyde
and its derivatives, amyliden-dimethyl and amyliden-diethyl ethers.
August Sayer (U.S.P., No. 470,451) finds diethyl-ketone, dibutyl-ketone,
di-pentyl-ketone, and the mixed ketones,[A] methyl-ethyl, methyl-propyl,
methyl-butyl, methyl-amyl, and ethyl-butyl ketones are active solvents of
pyroxyline; and Paget finds that although methyl-amyl oxide is a solvent,
that ethyl-amyl oxide is not.
[Footnote A: Ketones are derived from the fatty acids by the substitution
of the hydroxyl of the latter by a monad positive radical. They thus
resemble aldehydes in constitution. The best-known ketone is acetone
CH_{3}CO.CH_{3}. Mixed ketones are obtained by distilling together salts
of two different fatty acids. Thus potassic butyrate and potassic acetate form
propyl-methyl-ketone—
C(C_{2}H_{5})H_{2}
|
CO.CH_{3}]
The solvents of pyroxyline can be divided into general classes—First,
those which are solvents without the aid of heat or solution in alcohol;
second, those that are solvents when dissolved in alcohol. These solvents
Page 111
are those which also develop a solvent action when heated to their melting
point in combination with pyroxyline.
Mr W.D. Field groups the solvents of pyroxyline into classes thus: Two
of the monohydric alcohols; compound ethers of the fatty acids with
monohydric alcohols, aldehydes; simple and mixed ketones of the fatty acid
series. These four classes include the greater number of the solvents of
pyroxyline. Those not included are as follows:—Amyl-nitrate and nitrite,
methylene-di-methyl ether, ethidene-diethyl ether, amyl-chloracetate, nitro-
benzene and di-nitro-benzene, coumarin, camphor, glacial acetic acid, and
mono-, di-, and tri-acetin.
Richard Hale uses the following solvent:—Amyl-acetate, 4 volumes;
petroleum naphtha, 4 volumes; methyl-alcohol, 2 volumes; pyroxyline, 4 to
5 ounces to the gallon of solvent. Hale used petroleum naphtha to hasten the
drying qualities of the varnish, so that it would set on the article to be
varnished before it had a chance to run off. It is, however, the non-
hygroscopic character of the solvent that makes the varnish successful. This
formula is very largely used for the production of pyroxyline varnish, which
is used for varnishing pens, pencils, &c., also brass-work and silver-ware.
The body known as oxy-cellulose[A] is formed by the action of nitric
acid upon cellulose when boiled with it. The quantity formed is about 30
per cent. of cellulose acted upon. When washed free from acid, it
gelatinises. It is then soluble in dilute alkalies, and can be reprecipitated
from solution by alcohol, acids, or saline solutions. Messrs Cross and
Bevan assign to it the formula C_{18}H_{26}O_{16}. It dissolves in
concentrated sulphuric acid, and with nitric acid forms a nitro body of the
formula C_{18}H_{23}O_{16}3(NO_{2}), which is prepared as follows:
—The gelatinous oxy-cellulose is washed with strong nitric acid until free
from water, and is then diffused through a mixture of equal volumes of
point in combination with pyroxyline.
Mr W.D. Field groups the solvents of pyroxyline into classes thus: Two
of the monohydric alcohols; compound ethers of the fatty acids with
monohydric alcohols, aldehydes; simple and mixed ketones of the fatty acid
series. These four classes include the greater number of the solvents of
pyroxyline. Those not included are as follows:—Amyl-nitrate and nitrite,
methylene-di-methyl ether, ethidene-diethyl ether, amyl-chloracetate, nitro-
benzene and di-nitro-benzene, coumarin, camphor, glacial acetic acid, and
mono-, di-, and tri-acetin.
Richard Hale uses the following solvent:—Amyl-acetate, 4 volumes;
petroleum naphtha, 4 volumes; methyl-alcohol, 2 volumes; pyroxyline, 4 to
5 ounces to the gallon of solvent. Hale used petroleum naphtha to hasten the
drying qualities of the varnish, so that it would set on the article to be
varnished before it had a chance to run off. It is, however, the non-
hygroscopic character of the solvent that makes the varnish successful. This
formula is very largely used for the production of pyroxyline varnish, which
is used for varnishing pens, pencils, &c., also brass-work and silver-ware.
The body known as oxy-cellulose[A] is formed by the action of nitric
acid upon cellulose when boiled with it. The quantity formed is about 30
per cent. of cellulose acted upon. When washed free from acid, it
gelatinises. It is then soluble in dilute alkalies, and can be reprecipitated
from solution by alcohol, acids, or saline solutions. Messrs Cross and
Bevan assign to it the formula C_{18}H_{26}O_{16}. It dissolves in
concentrated sulphuric acid, and with nitric acid forms a nitro body of the
formula C_{18}H_{23}O_{16}3(NO_{2}), which is prepared as follows:
—The gelatinous oxy-cellulose is washed with strong nitric acid until free
from water, and is then diffused through a mixture of equal volumes of
Page 112
strong sulphuric and nitric acids, in which it quickly dissolves. The solution,
after standing for about an hour, is poured in a fine stream into a large
volume of water, by which the "nitro" body is precipitated as a white
flocculent mass. The product, after drying at 110° C., was found upon
analysis to contain 6.48 per cent. nitrogen.
[Footnote A: "On the Oxidation of Cellulose," by C.F. Cross and E.J.
Bevan, Jour. Chem. Soc., 1883, p. 22.]
MISCELLANEOUS NITRO-EXPLOSIVES.
~Nitro-Starch.~—It is only recently that, by means of the process
introduced by the "Actiengesellschaft Dynamit Nobel," it has been possible
to make this explosive upon the manufacturing scale. Nitro-starch has been
known since 1883, when Braconnot discovered it, and called it xyloidine.
Its formula is C_{6}H_{8}O_{3}(NO_{3})_{2}, but Dr Otto Mühlhäusen
has lately succeeded in preparing higher nitrated compounds, viz.:—
(a.) C_{6}H_{7-1/2}O_{2-1/2}(NO_{3})_{2-1/2}.
(b.) C_{6}H_{7}O_{4}(NO_{3})_{3}.
Or doubling the molecule of starch:—
Nitrogen.
i. Tetra-nitro-starch C_{12}H_{16}O_{6}(ONO_{2}){4} 11.11 per cent.
ii. Penta-nitro-starch C{12}H_{15}O_{5}(ONO_{2}){5} 12.75 "
iii. Hexa-nitro-starch C{12}H_{14}O_{4}(ONO_{2})_{6} 14.14 "
He regards them as true ethers (esters) of nitric acid. Thus on treatment
with sulphuric acid, these compounds yield NO_{3}H, the residue
O.NO_{2} thus appearing to be replaced by the sulphuric acid residue. On
treatment with a solution of ferrous chloride, nitric oxide and "soluble"
after standing for about an hour, is poured in a fine stream into a large
volume of water, by which the "nitro" body is precipitated as a white
flocculent mass. The product, after drying at 110° C., was found upon
analysis to contain 6.48 per cent. nitrogen.
[Footnote A: "On the Oxidation of Cellulose," by C.F. Cross and E.J.
Bevan, Jour. Chem. Soc., 1883, p. 22.]
MISCELLANEOUS NITRO-EXPLOSIVES.
~Nitro-Starch.~—It is only recently that, by means of the process
introduced by the "Actiengesellschaft Dynamit Nobel," it has been possible
to make this explosive upon the manufacturing scale. Nitro-starch has been
known since 1883, when Braconnot discovered it, and called it xyloidine.
Its formula is C_{6}H_{8}O_{3}(NO_{3})_{2}, but Dr Otto Mühlhäusen
has lately succeeded in preparing higher nitrated compounds, viz.:—
(a.) C_{6}H_{7-1/2}O_{2-1/2}(NO_{3})_{2-1/2}.
(b.) C_{6}H_{7}O_{4}(NO_{3})_{3}.
Or doubling the molecule of starch:—
Nitrogen.
i. Tetra-nitro-starch C_{12}H_{16}O_{6}(ONO_{2}){4} 11.11 per cent.
ii. Penta-nitro-starch C{12}H_{15}O_{5}(ONO_{2}){5} 12.75 "
iii. Hexa-nitro-starch C{12}H_{14}O_{4}(ONO_{2})_{6} 14.14 "
He regards them as true ethers (esters) of nitric acid. Thus on treatment
with sulphuric acid, these compounds yield NO_{3}H, the residue
O.NO_{2} thus appearing to be replaced by the sulphuric acid residue. On
treatment with a solution of ferrous chloride, nitric oxide and "soluble"
Page 113
starch are regenerated. On shaking with sulphuric acid over mercury, all the
nitrogen is split off as NO.
Tetra-nitro-starch is prepared upon the large scale as follows:—A
quantity of potato-starch is taken and exposed in some suitable desiccating
apparatus at a temperature of 100° C. until all the moisture which it
contains is completely driven off. It is then reduced to a fine powder by
grinding, and dissolved in nitric acid of specific gravity 1.501. The vessel in
which this solution is accomplished is made of lead, and must be provided
with two jackets, cooled by means of water. It should further be fitted with
a screw-agitator, in order to keep the nitric acid circulating freely. The
charge of starch is introduced through an opening in the cover of this
digesting vessel, and the proportions of acid to starch are 10 kilogrammes
of starch to 100 kilos. of acid. The temperature is kept within the limits 20°
to 25° C. When the solution of the starch is complete, the liquid is
conducted into a precipitating apparatus, which is also provided with a
cooling jacket, for the purpose of regulating the temperature. The bottom of
this vessel is double and perforated, and here is placed a layer of gun-cotton
to act as a filter. This vessel is filled with spent nitro-sulphuric acid obtained
as a waste product from the nitro-glycerine manufactory, and the solution of
starch in nitric acid is sprayed into it through an injector worked by
compressed air, whereby the nitro-starch is thrown down in the form of a
fine-grained powdery precipitate.
In order to precipitate 100 kilos. of the acid solution of starch, it is
necessary to employ 500 kilos. of spent nitro-sulphuric acid. As it is
precipitated the nitro-starch collects on the gun-cotton filter, and the acid
liquor is run off through a tap placed beneath the perforated double bottom
of the vessel, and of course below the filter pad. The precipitated starch is
further cleansed from acid by repeated washings and by pressure, until all
trace of acidity has been eliminated, and the substance exhibits a neutral
nitrogen is split off as NO.
Tetra-nitro-starch is prepared upon the large scale as follows:—A
quantity of potato-starch is taken and exposed in some suitable desiccating
apparatus at a temperature of 100° C. until all the moisture which it
contains is completely driven off. It is then reduced to a fine powder by
grinding, and dissolved in nitric acid of specific gravity 1.501. The vessel in
which this solution is accomplished is made of lead, and must be provided
with two jackets, cooled by means of water. It should further be fitted with
a screw-agitator, in order to keep the nitric acid circulating freely. The
charge of starch is introduced through an opening in the cover of this
digesting vessel, and the proportions of acid to starch are 10 kilogrammes
of starch to 100 kilos. of acid. The temperature is kept within the limits 20°
to 25° C. When the solution of the starch is complete, the liquid is
conducted into a precipitating apparatus, which is also provided with a
cooling jacket, for the purpose of regulating the temperature. The bottom of
this vessel is double and perforated, and here is placed a layer of gun-cotton
to act as a filter. This vessel is filled with spent nitro-sulphuric acid obtained
as a waste product from the nitro-glycerine manufactory, and the solution of
starch in nitric acid is sprayed into it through an injector worked by
compressed air, whereby the nitro-starch is thrown down in the form of a
fine-grained powdery precipitate.
In order to precipitate 100 kilos. of the acid solution of starch, it is
necessary to employ 500 kilos. of spent nitro-sulphuric acid. As it is
precipitated the nitro-starch collects on the gun-cotton filter, and the acid
liquor is run off through a tap placed beneath the perforated double bottom
of the vessel, and of course below the filter pad. The precipitated starch is
further cleansed from acid by repeated washings and by pressure, until all
trace of acidity has been eliminated, and the substance exhibits a neutral
Page 114
reaction. The next step is to treat the nitro-starch with a 5 per cent. solution
of soda, in contact with which it is allowed to stand for at least twenty-four
hours. The product is then ground up until a sort of "milk" or emulsion is
obtained, and lastly treated with a solution of aniline, so that when pressed
into cake, it contains about 33 per cent. of water, and 1 per cent. of aniline.
Dr Mühlhäusen, working on these lines in the laboratory, prepared nitro-
starch which contained 10.96 and 11.09 per cent. of nitrogen. When in the
state of powder it is snow-white in colour; it becomes electrified when
rubbed; it is very stable, and soluble even in the cold in nitro- glycerine. He
has also prepared a tetra-nitro-starch containing 10.58 and 10.50 per cent.
of nitrogen, by pouring water into a solution of starch in nitric acid which
had stood for several days. The substance thus produced in the laboratory
had all the properties of that prepared by the other process.
The production of penta-nitro-starch is effected by adding 20 grms. of
rice-starch—previously dried at a temperature of 100°C., in order to
eliminate all moisture—to a mixture of 100 grms. of nitric acid, specific
gravity 1.501, and 300 grms. of sulphuric acid, specific gravity 1.8 (some
tetra-nitro-starch is also formed at the same time). After standing in contact
with these mixed acids for one hour the starch has undergone a change, and
the mass may now be discharged into a large quantity of water, and then
washed, first with water, and finally with an aqueous solution of soda. The
yield in Dr Mühlhäusen's experiments was 147.5 per cent.
The substance thus formed is now heated with ether-alcohol, the ether is
distilled off, and the penta-nitro-starch appears as a precipitate, whilst the
tetra-nitro-starch, which is formed simultaneously, remains in solution in
the alcohol. As obtained by this process, it contained 12.76 and 12.98 per
cent. nitrogen, whilst the soluble tetra-nitro-starch contained 10.45 per cent.
of soda, in contact with which it is allowed to stand for at least twenty-four
hours. The product is then ground up until a sort of "milk" or emulsion is
obtained, and lastly treated with a solution of aniline, so that when pressed
into cake, it contains about 33 per cent. of water, and 1 per cent. of aniline.
Dr Mühlhäusen, working on these lines in the laboratory, prepared nitro-
starch which contained 10.96 and 11.09 per cent. of nitrogen. When in the
state of powder it is snow-white in colour; it becomes electrified when
rubbed; it is very stable, and soluble even in the cold in nitro- glycerine. He
has also prepared a tetra-nitro-starch containing 10.58 and 10.50 per cent.
of nitrogen, by pouring water into a solution of starch in nitric acid which
had stood for several days. The substance thus produced in the laboratory
had all the properties of that prepared by the other process.
The production of penta-nitro-starch is effected by adding 20 grms. of
rice-starch—previously dried at a temperature of 100°C., in order to
eliminate all moisture—to a mixture of 100 grms. of nitric acid, specific
gravity 1.501, and 300 grms. of sulphuric acid, specific gravity 1.8 (some
tetra-nitro-starch is also formed at the same time). After standing in contact
with these mixed acids for one hour the starch has undergone a change, and
the mass may now be discharged into a large quantity of water, and then
washed, first with water, and finally with an aqueous solution of soda. The
yield in Dr Mühlhäusen's experiments was 147.5 per cent.
The substance thus formed is now heated with ether-alcohol, the ether is
distilled off, and the penta-nitro-starch appears as a precipitate, whilst the
tetra-nitro-starch, which is formed simultaneously, remains in solution in
the alcohol. As obtained by this process, it contained 12.76 and 12.98 per
cent. nitrogen, whilst the soluble tetra-nitro-starch contained 10.45 per cent.
Page 115
Hexa-nitro-starch is the product chiefly formed when 40 grms. of dry
starch are treated with 400 grms. of nitric acid, specific gravity 1.501, and
allowed to stand in contact for twenty-four hours; 200 grms. of this mixture
are then poured into 600 c.c. of sulphuric acid of 66° B. The result of this
manipulation is a white precipitate, which contains 13.52-13.23 and 13.22
per cent. nitrogen; and consists, therefore, of a mixture of penta- and hexa-
nitro-starch.
The experiments undertaken with these substances demonstrated that
those prepared by precipitating the nitro-starch with strong sulphuric acid
were less stable in character or properties than those which were
precipitated by water or weak sulphuric acid. Dr Mühlhäusen is of opinion
that possibly in the former case a sulpho-group may be formed, which in
small quantity may occasion this instability.
The following table shows the behaviour of these substances prepared in
different ways and under various conditions:—
___________________________________________________________
_______ | | | | | SAMPLES. | |
|____________________________________________| | | | | | | | | | A. | B. |
C. | D. | E. | | Ignition-point |175° C. |170° C. |152° C. |121° C. |155° C. | |
Stability |Stable |Stable |Unstable|Unstable|Unstable| | Per cent. of N. | 11.02
| 10.54 | 12.87 | 12.59 | 13.52 | | 96 per cent. alcohol| Sol. | Sol. | Insol. |
Insol. | Insol. | | Ether | Insol. | Insol. | Insol. | Insol. | Insol. | | Ether-alcohol |
Sol. | Sol. | Sol. | Sol. | Sol. | | Acetic Ether | Sol. | Sol. | Sol. | Sol. | Sol. |
|_____________________|________|________|________|________|_____
___|
These samples were prepared as follows:—
starch are treated with 400 grms. of nitric acid, specific gravity 1.501, and
allowed to stand in contact for twenty-four hours; 200 grms. of this mixture
are then poured into 600 c.c. of sulphuric acid of 66° B. The result of this
manipulation is a white precipitate, which contains 13.52-13.23 and 13.22
per cent. nitrogen; and consists, therefore, of a mixture of penta- and hexa-
nitro-starch.
The experiments undertaken with these substances demonstrated that
those prepared by precipitating the nitro-starch with strong sulphuric acid
were less stable in character or properties than those which were
precipitated by water or weak sulphuric acid. Dr Mühlhäusen is of opinion
that possibly in the former case a sulpho-group may be formed, which in
small quantity may occasion this instability.
The following table shows the behaviour of these substances prepared in
different ways and under various conditions:—
___________________________________________________________
_______ | | | | | SAMPLES. | |
|____________________________________________| | | | | | | | | | A. | B. |
C. | D. | E. | | Ignition-point |175° C. |170° C. |152° C. |121° C. |155° C. | |
Stability |Stable |Stable |Unstable|Unstable|Unstable| | Per cent. of N. | 11.02
| 10.54 | 12.87 | 12.59 | 13.52 | | 96 per cent. alcohol| Sol. | Sol. | Insol. |
Insol. | Insol. | | Ether | Insol. | Insol. | Insol. | Insol. | Insol. | | Ether-alcohol |
Sol. | Sol. | Sol. | Sol. | Sol. | | Acetic Ether | Sol. | Sol. | Sol. | Sol. | Sol. |
|_____________________|________|________|________|________|_____
___|
These samples were prepared as follows:—
Page 116
A. From 1 part nitric acid and 2 parts sulphuric acid (containing 70 per
cent. H_{2}O).
B. From 1 part nitric acid and water.
C. From 1 part nitric and 3 parts H_{2}SO_{4} (con.).
D. From 1 part nitric and 3.5 parts con. H_{2}SO_{4}.
E. From 1 part nitric and 3 parts con. H_{2}SO_{4}.
Dr Mühlhäusen is of opinion that these compounds may be turned to
practical account in the production of good smokeless powder. He
recommends the following proportions and method. Six grms. of nitro-jute
and 2 grms. of nitro-starch are mixed together, and moistened with acetic
ether. These ingredients are then worked together into a uniform mass, and
dried at a temperature ranging between the limits 50° to 60° C. He has
himself prepared such a smokeless powder, which proved to contain 11.54
per cent. of nitrogen, and was very stable. Further details of Dr
Mühlhäusen's work upon nitro-starch can be found in Dingler's
Polytechnisches Journal, paper "Die höhren Salpetersäureäther der Stärke,"
1892, Band 284, s. 137-143, and a Bibliography up to 1892 in Arms and
Explosives, December 1892.
M. Berthelot gives the heat of formation of nitro-starch as 812 cals. for 1
grm., and the heat of total combustion as equal to 706.5 cals. for 207 grms.,
or for 1 grm. 3,413 cals. The heat of decomposition could only be
calculated if the products of decomposition were given, but they have not as
yet been studied, and the quantity of oxygen contained in the compound is
far from being sufficient for its complete combustion. Berthelot and Vieille
found the average velocities for nitro-starch powder, density of charge
about 1.2, in a tin tube 4 mm. external diameter, to be, in two experiments,
5,222 m. and 5,674 m. In a tin tube 5.5 mm. external diameter, the velocity
was 5,815 m., and in lead tube 5,006 m. (density 1.1 to 1.2). The starch
powder is hygroscopic, and is insoluble in water and alcohol. When dry it is
cent. H_{2}O).
B. From 1 part nitric acid and water.
C. From 1 part nitric and 3 parts H_{2}SO_{4} (con.).
D. From 1 part nitric and 3.5 parts con. H_{2}SO_{4}.
E. From 1 part nitric and 3 parts con. H_{2}SO_{4}.
Dr Mühlhäusen is of opinion that these compounds may be turned to
practical account in the production of good smokeless powder. He
recommends the following proportions and method. Six grms. of nitro-jute
and 2 grms. of nitro-starch are mixed together, and moistened with acetic
ether. These ingredients are then worked together into a uniform mass, and
dried at a temperature ranging between the limits 50° to 60° C. He has
himself prepared such a smokeless powder, which proved to contain 11.54
per cent. of nitrogen, and was very stable. Further details of Dr
Mühlhäusen's work upon nitro-starch can be found in Dingler's
Polytechnisches Journal, paper "Die höhren Salpetersäureäther der Stärke,"
1892, Band 284, s. 137-143, and a Bibliography up to 1892 in Arms and
Explosives, December 1892.
M. Berthelot gives the heat of formation of nitro-starch as 812 cals. for 1
grm., and the heat of total combustion as equal to 706.5 cals. for 207 grms.,
or for 1 grm. 3,413 cals. The heat of decomposition could only be
calculated if the products of decomposition were given, but they have not as
yet been studied, and the quantity of oxygen contained in the compound is
far from being sufficient for its complete combustion. Berthelot and Vieille
found the average velocities for nitro-starch powder, density of charge
about 1.2, in a tin tube 4 mm. external diameter, to be, in two experiments,
5,222 m. and 5,674 m. In a tin tube 5.5 mm. external diameter, the velocity
was 5,815 m., and in lead tube 5,006 m. (density 1.1 to 1.2). The starch
powder is hygroscopic, and is insoluble in water and alcohol. When dry it is
Page 117
very explosive, and takes fire at about 350° F. Mr Alfred Nobel has taken
out a patent (Eng. Pat. No. 6,560, 88) for the use of nitro-starch. His
invention relates to the treatment of nitro- starch and nitro-dextrine, for the
purpose of producing an explosive powder, to be used in place of
gunpowder. He incorporates these materials with nitro-cellulose, and
dissolves the whole in acetone, which is afterwards distilled off. A perfect
incorporation of the ingredients is thus brought about.
~Nitro-Jute.~—It is obtained by treating jute with nitric acid. Its
properties have been studied by Messrs Cross and Bevan (Jour. Chem. Soc.,
1889, 199), and by Mühlhäusen. The latter used for its nitration an acid
mixture composed of equal parts of nitric and sulphuric acids, which was
allowed to act upon the jute for some time. He found that with long
exposure, i.e., from three to four hours in the acids, there was a
disintegrating of the fibre-bundles, and the nitration was attended by
secondary decomposition and conversion into products soluble in the acid
mixture. Cross and Bevan's work upon this subject leads them to conclude
that the highest yield of nitrate is represented by an increase of weight of 51
per cent. They give jute the empirical formula C_{12}H_{18}O_{9} (C =
47 per cent. H = 6 per cent., and O = 47 per cent.), and believe its
conversion into a nitro compound to take place thus:—
C_{12}H_{18}O + 3HNO_{3} = C_{12}H_{15}O_{6}(NO_{3}){3} + 3H{2}O.
This is equivalent to a gain in weight of 44 per cent. for the tri- nitrate,
and of 58 per cent. for the tetra-nitrate. The formation of the tetra-nitrate
appears to be the limit of nitration of jute-fibre. In other words, if we
represent the ligno-cellulose molecule by a C_{12} formula, it will contain
four hydroxyl (OH) groups, or two less than cellulose similarly represented.
The following are their nitration results:—
out a patent (Eng. Pat. No. 6,560, 88) for the use of nitro-starch. His
invention relates to the treatment of nitro- starch and nitro-dextrine, for the
purpose of producing an explosive powder, to be used in place of
gunpowder. He incorporates these materials with nitro-cellulose, and
dissolves the whole in acetone, which is afterwards distilled off. A perfect
incorporation of the ingredients is thus brought about.
~Nitro-Jute.~—It is obtained by treating jute with nitric acid. Its
properties have been studied by Messrs Cross and Bevan (Jour. Chem. Soc.,
1889, 199), and by Mühlhäusen. The latter used for its nitration an acid
mixture composed of equal parts of nitric and sulphuric acids, which was
allowed to act upon the jute for some time. He found that with long
exposure, i.e., from three to four hours in the acids, there was a
disintegrating of the fibre-bundles, and the nitration was attended by
secondary decomposition and conversion into products soluble in the acid
mixture. Cross and Bevan's work upon this subject leads them to conclude
that the highest yield of nitrate is represented by an increase of weight of 51
per cent. They give jute the empirical formula C_{12}H_{18}O_{9} (C =
47 per cent. H = 6 per cent., and O = 47 per cent.), and believe its
conversion into a nitro compound to take place thus:—
C_{12}H_{18}O + 3HNO_{3} = C_{12}H_{15}O_{6}(NO_{3}){3} + 3H{2}O.
This is equivalent to a gain in weight of 44 per cent. for the tri- nitrate,
and of 58 per cent. for the tetra-nitrate. The formation of the tetra-nitrate
appears to be the limit of nitration of jute-fibre. In other words, if we
represent the ligno-cellulose molecule by a C_{12} formula, it will contain
four hydroxyl (OH) groups, or two less than cellulose similarly represented.
The following are their nitration results:—
Page 118
Acids used.—I. HNO_{3} sp. gr. 1.43, and H_{2}SO_{4} = 1.84 equal
parts.
II. 1 vol. HNO_{3}(1.5), 1 vol. H_{2}SO_{4}(1.84).
III. 1 vol. HNO_{3}(1.5), 75 vols. H_{2}SO_{4}(1.84).
I. = 144.4; II. = 153.3; III. = 154.4 grms.; 100 grms. of fibre being used
in all three cases.
Duration of exposure, thirty minutes at 18° C.
The nitrogen was determined in the products, and equalled 10.5 per cent.
Theory for C_{12}H_{15}O_{6}(NO_{3}){3} = 9.5 per cent. and for
C{12}H_{15}O_{6}(NO_{3})_{4} = 11.5 per cent. These nitrates
resemble those of cellulose, and are in all essential points nitrates of ligno-
cellulose.
Mühlhäusen obtained a much lower yield, and probably, as pointed out
by Cross and Bevan, a secondary decomposition took place, and his
products, therefore, probably approximate to the derivatives of cellulose
rather than to those of ligno-cellulose, the more oxidisable, non-cellulose,
or lignone constituents having been decomposed. In fact, he regards his
product as cellulose penta-nitrate (C_{12}H_{16}O_{5}(ONO_{2})_{5}).
The Chemiker Zeitung, xxi., p. 163, contains a further paper by Mühlhäusen
on the explosive nitro-jute. After purifying the jute-fibre by boiling it with a
1 per cent. solution of sodium carbonate, and washing with water, he treated
1 part of the purified jute with 15 parts of nitro-sulphuric acid, and obtained
the following results with different proportions of nitric to sulphuric acids:
—
Yield Ignition Nitrogen.
per cent. Point.
Experiment I.— 1. HNO_{3} 1. H_{2}SO_{4} 129.5 170° C. 11.96%
parts.
II. 1 vol. HNO_{3}(1.5), 1 vol. H_{2}SO_{4}(1.84).
III. 1 vol. HNO_{3}(1.5), 75 vols. H_{2}SO_{4}(1.84).
I. = 144.4; II. = 153.3; III. = 154.4 grms.; 100 grms. of fibre being used
in all three cases.
Duration of exposure, thirty minutes at 18° C.
The nitrogen was determined in the products, and equalled 10.5 per cent.
Theory for C_{12}H_{15}O_{6}(NO_{3}){3} = 9.5 per cent. and for
C{12}H_{15}O_{6}(NO_{3})_{4} = 11.5 per cent. These nitrates
resemble those of cellulose, and are in all essential points nitrates of ligno-
cellulose.
Mühlhäusen obtained a much lower yield, and probably, as pointed out
by Cross and Bevan, a secondary decomposition took place, and his
products, therefore, probably approximate to the derivatives of cellulose
rather than to those of ligno-cellulose, the more oxidisable, non-cellulose,
or lignone constituents having been decomposed. In fact, he regards his
product as cellulose penta-nitrate (C_{12}H_{16}O_{5}(ONO_{2})_{5}).
The Chemiker Zeitung, xxi., p. 163, contains a further paper by Mühlhäusen
on the explosive nitro-jute. After purifying the jute-fibre by boiling it with a
1 per cent. solution of sodium carbonate, and washing with water, he treated
1 part of the purified jute with 15 parts of nitro-sulphuric acid, and obtained
the following results with different proportions of nitric to sulphuric acids:
—
Yield Ignition Nitrogen.
per cent. Point.
Experiment I.— 1. HNO_{3} 1. H_{2}SO_{4} 129.5 170° C. 11.96%
Page 119
" II. " 2. " 132.2 167° C. 12.15%
" III. " 3. " 135.8 169° C. 11.91%
An experiment made with fine carded jute and the same mixture of acids
as in No. II. gave 145.4 per cent. nitro-jute, which ignited at 192° C., and
contained 12 per cent. nitrogen. This explosive is not at present
manufactured upon the large scale, and Messrs Cross and Bevan are of
opinion that there is no very obvious advantage in the use of lignified textile
fibre as raw materials for explosive nitrates, seeing that a large number of
raw materials containing cellulose (chiefly as cotton) can be obtained at a
cheaper rate, and yield also 150 to 170 per cent. of explosive material when
nitrated, and are in many ways superior to the products obtained hitherto
from jute.
~Nitro-mannite~ is formed by the action of nitric acid on mannite, a hex-
acid alcohol closely related to sugar. It occurs abundantly in manna, which
is the partly dried sap of the manna-ash (Fraxinus ornus). It is formed in the
lactic acid fermentation of sugar, and by the action of nascent hydrogen on
glucose and cellulose, or on invert sugar. Its formula is C_{6}H_{8}(OH)
{6} and that of nitro-mannite C{6}H_{8}(NO_{3})_{6}. Mannite
crystallises in needles or rhombic prisms, which are soluble in water and
alcohol, and have a sweet taste. Nitro-mannite forms white needle-shaped
crystals, insoluble in water, but soluble in ether or alcohol. When rapidly
heated, they ignite at about 374° F., and explode at about 590° F. It is more
susceptible to friction and percussion than nitro-glycerine, and unless pure
it is liable to spontaneous decomposition. It is considered as the nitric ether
of the hexatomic alcohol mannite. It is formed by the action of a mixture of
nitric and sulphuric acids upon mannite—
C_{6}H_{8}(OH){6} + 6HNO{3} = C_{6}H_{8}(NO_{3}){6} + 6H{2}O.
Its products of explosion are as shown in the following equation:—
" III. " 3. " 135.8 169° C. 11.91%
An experiment made with fine carded jute and the same mixture of acids
as in No. II. gave 145.4 per cent. nitro-jute, which ignited at 192° C., and
contained 12 per cent. nitrogen. This explosive is not at present
manufactured upon the large scale, and Messrs Cross and Bevan are of
opinion that there is no very obvious advantage in the use of lignified textile
fibre as raw materials for explosive nitrates, seeing that a large number of
raw materials containing cellulose (chiefly as cotton) can be obtained at a
cheaper rate, and yield also 150 to 170 per cent. of explosive material when
nitrated, and are in many ways superior to the products obtained hitherto
from jute.
~Nitro-mannite~ is formed by the action of nitric acid on mannite, a hex-
acid alcohol closely related to sugar. It occurs abundantly in manna, which
is the partly dried sap of the manna-ash (Fraxinus ornus). It is formed in the
lactic acid fermentation of sugar, and by the action of nascent hydrogen on
glucose and cellulose, or on invert sugar. Its formula is C_{6}H_{8}(OH)
{6} and that of nitro-mannite C{6}H_{8}(NO_{3})_{6}. Mannite
crystallises in needles or rhombic prisms, which are soluble in water and
alcohol, and have a sweet taste. Nitro-mannite forms white needle-shaped
crystals, insoluble in water, but soluble in ether or alcohol. When rapidly
heated, they ignite at about 374° F., and explode at about 590° F. It is more
susceptible to friction and percussion than nitro-glycerine, and unless pure
it is liable to spontaneous decomposition. It is considered as the nitric ether
of the hexatomic alcohol mannite. It is formed by the action of a mixture of
nitric and sulphuric acids upon mannite—
C_{6}H_{8}(OH){6} + 6HNO{3} = C_{6}H_{8}(NO_{3}){6} + 6H{2}O.
Its products of explosion are as shown in the following equation:—
Page 120
C_{6}H_{8}(OH){6} = 6CO{2} + 4H_{2}O + 3N_{2} + O_{2}.
Its percentage composition is as follows:—Carbon, 15.9 per cent.;
hydrogen, 1.8 per cent.; nitrogen, 18.6 per cent.; and oxygen, 63.7 per cent.
Its melting point is 112 to 113° C., and it solidifies at 93°. When carefully
prepared and purified by recrystallisation from alcohol, and kept protected
from sunlight, it can be kept for several years without alteration.
Its percentage composition is as follows:—Carbon, 15.9 per cent.;
hydrogen, 1.8 per cent.; nitrogen, 18.6 per cent.; and oxygen, 63.7 per cent.
Its melting point is 112 to 113° C., and it solidifies at 93°. When carefully
prepared and purified by recrystallisation from alcohol, and kept protected
from sunlight, it can be kept for several years without alteration.
Page 121
Nitro-mannite is more dangerous than nitro-glycerine, as it is more
sensitive to shock. It is intermediate in its shattering properties between
nitro-glycerine and fulminate of mercury. It explodes by the shock of
copper on iron or copper, and even of porcelain on porcelain, provided the
latter shock be violent. Its heat of formation from its elements is +156.1
calories. It is not manufactured upon the commercial scale.
Besides the nitro compounds already described, there are many others,
but they are of little importance, and are none of them made upon the large
scale. Among such substances are nitro-coal, which is made by the action of
nitric acid on coal; nitro-colle, a product which results from the action of
nitric acid on isinglass or gelatine, soaked in water. It is then treated with
the usual acids.
Another method is to place strong glue in cold water until it has absorbed
the maximum amount of the latter. The mixture is solidified by the addition
of nitric acid, nitrated in the usual way, and well washed. Abel's Glyoxiline
is only nitrated gun-cotton impregnated with nitro- glycerine. Nitro-lignine
is only nitro-cellulose made from wood instead of cotton; and nitro-straw is
also only nitro-cellulose. The explosive known as Keil's Explosive contains
nitro-glucose. Nitro-molasses, which is a liquid product, has also been
proposed, and nitro-saccharose, the product obtained by the nitration of
sugar. It is a white, sandy, explosive substance, soluble in alcohol and ether.
When made from cane sugar, it does not crystallise; but if made from milk
sugar, it does. It has been used in percussion caps, being stronger and
quicker than nitro-glycerine. It is, however, very sensitive and very
hygroscopic, and very prone to decomposition. Nitro-tar, made from crude
tar-oil, by nitration with nitric acid of a specific gravity of 1.53 to 1.54.
Nitro-toluol is used, mixed with nitro-glycerine. This list, however, does not
exhaust the various substances that have been nitrated and proposed as
sensitive to shock. It is intermediate in its shattering properties between
nitro-glycerine and fulminate of mercury. It explodes by the shock of
copper on iron or copper, and even of porcelain on porcelain, provided the
latter shock be violent. Its heat of formation from its elements is +156.1
calories. It is not manufactured upon the commercial scale.
Besides the nitro compounds already described, there are many others,
but they are of little importance, and are none of them made upon the large
scale. Among such substances are nitro-coal, which is made by the action of
nitric acid on coal; nitro-colle, a product which results from the action of
nitric acid on isinglass or gelatine, soaked in water. It is then treated with
the usual acids.
Another method is to place strong glue in cold water until it has absorbed
the maximum amount of the latter. The mixture is solidified by the addition
of nitric acid, nitrated in the usual way, and well washed. Abel's Glyoxiline
is only nitrated gun-cotton impregnated with nitro- glycerine. Nitro-lignine
is only nitro-cellulose made from wood instead of cotton; and nitro-straw is
also only nitro-cellulose. The explosive known as Keil's Explosive contains
nitro-glucose. Nitro-molasses, which is a liquid product, has also been
proposed, and nitro-saccharose, the product obtained by the nitration of
sugar. It is a white, sandy, explosive substance, soluble in alcohol and ether.
When made from cane sugar, it does not crystallise; but if made from milk
sugar, it does. It has been used in percussion caps, being stronger and
quicker than nitro-glycerine. It is, however, very sensitive and very
hygroscopic, and very prone to decomposition. Nitro-tar, made from crude
tar-oil, by nitration with nitric acid of a specific gravity of 1.53 to 1.54.
Nitro-toluol is used, mixed with nitro-glycerine. This list, however, does not
exhaust the various substances that have been nitrated and proposed as
Page 122
explosives. Even such unlikely substances as horse dung have been
experimented with. None of them are very much used, and very few of
them are made upon the manufacturing scale.
experimented with. None of them are very much used, and very few of
them are made upon the manufacturing scale.
Page 123
CHAPTER IV.
DYNAMITE AND GELATINES.
Kieselguhr Dynamite—Classification of Dynamites—Properties and
Efficiency of Ordinary Dynamite—Other Forms of Dynamite—Gelatine
and
Gelatine Dynamites, Suitable Gun-Cotton for, and Treatment of—Other
Materials used—Composition of Gelignite—Blasting Gelatine—Gelatine
Dynamite—Absorbing Materials—Wood Pulp—Potassium Nitrate, &c.—
Manufacture and Apparatus used, and Properties of Gelatine Dynamites—
Cordite—Composition and Manufacture.
~Dynamite.~—Dynamite consists of nitro-glycerine either absorbed by
some porous material, or mixed with some other substance or substances
which are either explosives or merely inert materials. Among the porous
substances used is kieselguhr, a silicious earth which consists chiefly of the
skeletons of various species of diatoms. This earth occurs in beds chiefly in
Hanover, Sweden, and Scotland. The best quality for the purpose of
manufacturing dynamite is that which contains the largest quantity of the
long tubular bacillariæ, and less of the round and lancet-shaped forms, such
as pleurosigmata and diclyochæ, as the tube-shaped diatoms absorb the
nitro-glycerine better, and it becomes packed into the centre of the silicious
DYNAMITE AND GELATINES.
Kieselguhr Dynamite—Classification of Dynamites—Properties and
Efficiency of Ordinary Dynamite—Other Forms of Dynamite—Gelatine
and
Gelatine Dynamites, Suitable Gun-Cotton for, and Treatment of—Other
Materials used—Composition of Gelignite—Blasting Gelatine—Gelatine
Dynamite—Absorbing Materials—Wood Pulp—Potassium Nitrate, &c.—
Manufacture and Apparatus used, and Properties of Gelatine Dynamites—
Cordite—Composition and Manufacture.
~Dynamite.~—Dynamite consists of nitro-glycerine either absorbed by
some porous material, or mixed with some other substance or substances
which are either explosives or merely inert materials. Among the porous
substances used is kieselguhr, a silicious earth which consists chiefly of the
skeletons of various species of diatoms. This earth occurs in beds chiefly in
Hanover, Sweden, and Scotland. The best quality for the purpose of
manufacturing dynamite is that which contains the largest quantity of the
long tubular bacillariæ, and less of the round and lancet-shaped forms, such
as pleurosigmata and diclyochæ, as the tube-shaped diatoms absorb the
nitro-glycerine better, and it becomes packed into the centre of the silicious
Page 124
skeleton of the diatoms, the skeleton acting as a kind of tamping, and
increasing the intensity of the explosion.
Dynamites are classified by the late Colonel Cundill, R.A., in his
"Dictionary of Explosives" as follows:—
1. Dynamites with an inert base, acting merely as an absorbent.
2. Dynamites with an active base, i.e., an explosive base. No. 2 may be
again divided into three minor classes, which contain as base—
(a.) Charcoal.
(b.) Gunpowder or other nitrate, or chlorate mixture.
(c.) Gun-cotton or other nitro compound (nitro-benzol, &c.).
The first of these, viz., charcoal, was one of the first absorbents for nitro-
glycerine ever used; the second is represented by the well-known Atlas
powder; and the last includes the well-known and largely used gelatine
compounds, viz., gelignite and gelatine dynamite, and also tonite No. 3, &c.
In the year 1867 Nobel produced dynamite by absorbing the nitro-
glycerine in an inert substance, forming a plastic mass. In his patent he
says: "This invention relates to the use of nitro-glycerine in an altered
condition, which renders it far more practical and safe for use. The altered
condition of the nitro-glycerine is effected by causing it to be absorbed in
porous unexplosive substances, such as charcoal, silica, paper, or similar
materials, whereby it is converted into a powder, which I call dynamite, or
Nobel's safety powder. By the absorption of the nitro- glycerine in some
porous substance it acquires the property of being in a high degree
insensible to shocks, and it can also be burned over a fire without
exploding."
increasing the intensity of the explosion.
Dynamites are classified by the late Colonel Cundill, R.A., in his
"Dictionary of Explosives" as follows:—
1. Dynamites with an inert base, acting merely as an absorbent.
2. Dynamites with an active base, i.e., an explosive base. No. 2 may be
again divided into three minor classes, which contain as base—
(a.) Charcoal.
(b.) Gunpowder or other nitrate, or chlorate mixture.
(c.) Gun-cotton or other nitro compound (nitro-benzol, &c.).
The first of these, viz., charcoal, was one of the first absorbents for nitro-
glycerine ever used; the second is represented by the well-known Atlas
powder; and the last includes the well-known and largely used gelatine
compounds, viz., gelignite and gelatine dynamite, and also tonite No. 3, &c.
In the year 1867 Nobel produced dynamite by absorbing the nitro-
glycerine in an inert substance, forming a plastic mass. In his patent he
says: "This invention relates to the use of nitro-glycerine in an altered
condition, which renders it far more practical and safe for use. The altered
condition of the nitro-glycerine is effected by causing it to be absorbed in
porous unexplosive substances, such as charcoal, silica, paper, or similar
materials, whereby it is converted into a powder, which I call dynamite, or
Nobel's safety powder. By the absorption of the nitro- glycerine in some
porous substance it acquires the property of being in a high degree
insensible to shocks, and it can also be burned over a fire without
exploding."
Page 125
Ordinary dynamite consists of a mixture of 75 per cent. of nitro-glycerine
and 25 per cent. of kieselguhr. The guhr as imported (Messrs A. Haake &
Co. are the chief importers) contains from 20 to 30 per cent. of water and
organic matter. The water may be very easily estimated by drying a
weighed quantity in a platinum crucible at 100° C. for some time and re-
weighing, and the organic matter by igniting the residue strongly over a
Bunsen burner. Before the guhr can be used for making dynamite it must be
calcined, in order not only to get rid of moisture, but also the organic
matter.
A good guhr should absorb four times its weight of nitro-glycerine, and
should then form a comparatively dry mixture. It should be pale pink, red
brown, or white. The pink is generally preferred, and it should be as free as
possible from grit of all kinds, quartz particles, &c., and should have a
smooth feeling when rubbed between the finger and thumb, and should
show a large quantity of diatoms when viewed under the microscope. The
following was the analysis of a dried sample of kieselguhr:—Silica, 94.30;
magnesia, 2.10; oxide of iron and alumina, 1.3; organic matter, 0.40;
moisture, 1.90 per cent.
The guhr is generally dried in a reverberatory muffle furnace. It is spread
out on the bottom to the thickness of 3 or 4 inches, and should every now
and then be turned over and raked about with an iron rabble or hoe. The
temperature should be sufficiently high to make the guhr red hot, or the
organic matter will not be burnt off. The time occupied in calcining will
depend of course upon the quality of the guhr being operated upon. Those
containing a high percentage of water and organic matter will of course take
longer than those that do not. A sample of the calcined guhr should not
contain more than 0.5 per cent. of moisture and organic matter together.
and 25 per cent. of kieselguhr. The guhr as imported (Messrs A. Haake &
Co. are the chief importers) contains from 20 to 30 per cent. of water and
organic matter. The water may be very easily estimated by drying a
weighed quantity in a platinum crucible at 100° C. for some time and re-
weighing, and the organic matter by igniting the residue strongly over a
Bunsen burner. Before the guhr can be used for making dynamite it must be
calcined, in order not only to get rid of moisture, but also the organic
matter.
A good guhr should absorb four times its weight of nitro-glycerine, and
should then form a comparatively dry mixture. It should be pale pink, red
brown, or white. The pink is generally preferred, and it should be as free as
possible from grit of all kinds, quartz particles, &c., and should have a
smooth feeling when rubbed between the finger and thumb, and should
show a large quantity of diatoms when viewed under the microscope. The
following was the analysis of a dried sample of kieselguhr:—Silica, 94.30;
magnesia, 2.10; oxide of iron and alumina, 1.3; organic matter, 0.40;
moisture, 1.90 per cent.
The guhr is generally dried in a reverberatory muffle furnace. It is spread
out on the bottom to the thickness of 3 or 4 inches, and should every now
and then be turned over and raked about with an iron rabble or hoe. The
temperature should be sufficiently high to make the guhr red hot, or the
organic matter will not be burnt off. The time occupied in calcining will
depend of course upon the quality of the guhr being operated upon. Those
containing a high percentage of water and organic matter will of course take
longer than those that do not. A sample of the calcined guhr should not
contain more than 0.5 per cent. of moisture and organic matter together.
Page 126
After the guhr is dry it requires to be sifted and crushed. The crushing is
done by passing it between iron rollers fixed at the bottom of a cone or
hopper, and revolving at a moderate speed. Beneath the rollers a fine sieve
should be placed, through which the guhr must be made to pass.
The kieselguhr having been dried, crushed, and sifted, should be packed
away in bags, and care should be taken that it does not again absorb
moisture, as if it contains anything above about five-tenths per cent. of
water it will cause the dynamite made with it to exude. The guhr thus
prepared is taken up to the danger area, and mixed with nitro-glycerine. The
nitro-glycerine used should be quite free from water, and clear, and should
have been standing for a day or two in the precipitating house. The guhr and
nitro-glycerine are mixed in lead tanks (about 1-1/2 foot deep, and 2 to 3
feet long), in the proportions of 75 of the nitro-glycerine to 25 of the guhr,
unless the guhr is found to be too absorbent, which will cause the dynamite
to be too dry and to crumble. In this case a small quantity of barium
sulphate, say about 1 per cent., should be added to the guhr. This will lessen
its absorbing powers, or a highly absorptive sample of guhr may be mixed
with one of less absorptive power, in the proportions found by experiment
to be the best suited to make a fairly moist dynamite, but one that will not
exude.
The mixing itself is generally performed in a separate house. In a series
of lead-lined tanks the guhr is weighed, placed in a tank, and the nitro-
glycerine poured on to it. The nitro-glycerine may be weighed out in
indiarubber buckets. The whole is then mixed by hand, and well rubbed
between the hands, and afterwards passed through a sieve. At this stage the
dynamite should be dry and powdery, and of a uniform colour.
It is now ready to be made up into cartridges, and should be taken over to
the cartridge huts. These are small buildings surrounded with mounds, and
done by passing it between iron rollers fixed at the bottom of a cone or
hopper, and revolving at a moderate speed. Beneath the rollers a fine sieve
should be placed, through which the guhr must be made to pass.
The kieselguhr having been dried, crushed, and sifted, should be packed
away in bags, and care should be taken that it does not again absorb
moisture, as if it contains anything above about five-tenths per cent. of
water it will cause the dynamite made with it to exude. The guhr thus
prepared is taken up to the danger area, and mixed with nitro-glycerine. The
nitro-glycerine used should be quite free from water, and clear, and should
have been standing for a day or two in the precipitating house. The guhr and
nitro-glycerine are mixed in lead tanks (about 1-1/2 foot deep, and 2 to 3
feet long), in the proportions of 75 of the nitro-glycerine to 25 of the guhr,
unless the guhr is found to be too absorbent, which will cause the dynamite
to be too dry and to crumble. In this case a small quantity of barium
sulphate, say about 1 per cent., should be added to the guhr. This will lessen
its absorbing powers, or a highly absorptive sample of guhr may be mixed
with one of less absorptive power, in the proportions found by experiment
to be the best suited to make a fairly moist dynamite, but one that will not
exude.
The mixing itself is generally performed in a separate house. In a series
of lead-lined tanks the guhr is weighed, placed in a tank, and the nitro-
glycerine poured on to it. The nitro-glycerine may be weighed out in
indiarubber buckets. The whole is then mixed by hand, and well rubbed
between the hands, and afterwards passed through a sieve. At this stage the
dynamite should be dry and powdery, and of a uniform colour.
It is now ready to be made up into cartridges, and should be taken over to
the cartridge huts. These are small buildings surrounded with mounds, and
Page 127
contain a single cartridge machine. Each hut requires three girls—one to
work the press, and two to wrap up the cartridges. The cartridge press
consists of a short cylinder of the diameter of the cartridge that it is
intended to make. Into this cylinder a piston, pointed with ivory or lignum
vitæ wood, works up and down from a spring worked by a lever. Round the
upper edge of the cylinder is fastened a canvas bag, into which the powdery
dynamite is placed by means of a wooden scoop, and the descending piston
forces the dynamite down the cylinder and out of the open end, where the
compressed dynamite can be broken off at convenient lengths. The whole
machine should be made of gun-metal, and should be upright against the
wall of the building. The two girls, who sit at tables placed on each side of
the press, wrap the cartridges in parchment paper. From these huts the
cartridges are collected by boys every ten minutes or a quarter of an hour,
and taken to the packing room, where they are packed in 5-lb. cardboard
boxes, which are then further packed in deal boxes lined with indiarubber,
and fastened down air tight. The wooden lids are then nailed down with
brass or zinc nails, and a label pasted on the outside giving the weight and
description of the contents. The boxes should then be removed to the
magazines. It is well to take a certain number of cartridges from the packing
house at different times during the day, say three or four samples, and to test
them by the heat test. A sample cut from a cartridge, about 1 inch long,
should be placed under a glass shade, together with water (a large
desiccator, in fact), and left for some days. A good dynamite should not,
under these conditions, show any signs of exudation, even after weeks.[A]
[Footnote A: For analysis of dynamite, see chapter on "Analysis," and
author's article in Chem. News, 23rd September 1892.]
~Properties of Kieselguhr Dynamite.~—One cubic foot of dynamite
weighs 76 lbs. 4 oz. The specific gravity of 75 per cent. dynamite is,
however, 1.50. It is a red or grey colour, and rather greasy to the touch. It is
work the press, and two to wrap up the cartridges. The cartridge press
consists of a short cylinder of the diameter of the cartridge that it is
intended to make. Into this cylinder a piston, pointed with ivory or lignum
vitæ wood, works up and down from a spring worked by a lever. Round the
upper edge of the cylinder is fastened a canvas bag, into which the powdery
dynamite is placed by means of a wooden scoop, and the descending piston
forces the dynamite down the cylinder and out of the open end, where the
compressed dynamite can be broken off at convenient lengths. The whole
machine should be made of gun-metal, and should be upright against the
wall of the building. The two girls, who sit at tables placed on each side of
the press, wrap the cartridges in parchment paper. From these huts the
cartridges are collected by boys every ten minutes or a quarter of an hour,
and taken to the packing room, where they are packed in 5-lb. cardboard
boxes, which are then further packed in deal boxes lined with indiarubber,
and fastened down air tight. The wooden lids are then nailed down with
brass or zinc nails, and a label pasted on the outside giving the weight and
description of the contents. The boxes should then be removed to the
magazines. It is well to take a certain number of cartridges from the packing
house at different times during the day, say three or four samples, and to test
them by the heat test. A sample cut from a cartridge, about 1 inch long,
should be placed under a glass shade, together with water (a large
desiccator, in fact), and left for some days. A good dynamite should not,
under these conditions, show any signs of exudation, even after weeks.[A]
[Footnote A: For analysis of dynamite, see chapter on "Analysis," and
author's article in Chem. News, 23rd September 1892.]
~Properties of Kieselguhr Dynamite.~—One cubic foot of dynamite
weighs 76 lbs. 4 oz. The specific gravity of 75 per cent. dynamite is,
however, 1.50. It is a red or grey colour, and rather greasy to the touch. It is
Page 128
much less sensitive to shock than nitro-glycerine, but explodes occasionally
with the shock of a rifle bullet, or when struck. The addition of a few per
cent. of camphor will considerably diminish its explosive qualities to such
an extent that it can be made non-explosive except to a very strong
fulminate detonator. The direct contact of water disintegrates dynamite,
separating the nitro-glycerine, hence great caution is necessary in using it in
wet places. It freezes at about 40° Fahr. (4° C.), and remains frozen at
temperatures considerably exceeding that point. When frozen, it is
comparatively useless as an explosive agent, and must be thawed with care.
This is best done by placing the cartridges in a warming pan, which consists
of a tin can, with double sides and bottom, into which hot water (130°
Fahr.) can be poured. The dynamite will require to be left in for some
considerable time before it becomes soft. On no account must it be placed
on a hot stove or near a fire, as many serious accidents have occurred in this
way.
Frozen dynamite is a hard mass, with altered properties, and requires 1.5
grm. of fulminate instead of 0.5 grm. to explode it. Thawing may also cause
exudation of the nitro-glycerine, which is much more sensitive to shock,
and if accidentally struck with an iron tool, may explode. It is a dangerous
thing to cut a frozen cartridge with a knife. Ramming is even more
dangerous; in fact it is not only dangerous, but wasteful, to use dynamite
when in a frozen state.
Dynamite explodes at a temperature of 360° Fahr., and is very sensitive
to friction when hot. In hot countries it should never be exposed to the rays
of the sun. It should, however, not be kept in a damp or moist place, as this
is liable to cause exudation. Sunlight, if direct, can cause a slow
decomposition, as with all nitro and nitric compounds. Electric sparks
ignite, without exploding it, at least when operating in the open air.
with the shock of a rifle bullet, or when struck. The addition of a few per
cent. of camphor will considerably diminish its explosive qualities to such
an extent that it can be made non-explosive except to a very strong
fulminate detonator. The direct contact of water disintegrates dynamite,
separating the nitro-glycerine, hence great caution is necessary in using it in
wet places. It freezes at about 40° Fahr. (4° C.), and remains frozen at
temperatures considerably exceeding that point. When frozen, it is
comparatively useless as an explosive agent, and must be thawed with care.
This is best done by placing the cartridges in a warming pan, which consists
of a tin can, with double sides and bottom, into which hot water (130°
Fahr.) can be poured. The dynamite will require to be left in for some
considerable time before it becomes soft. On no account must it be placed
on a hot stove or near a fire, as many serious accidents have occurred in this
way.
Frozen dynamite is a hard mass, with altered properties, and requires 1.5
grm. of fulminate instead of 0.5 grm. to explode it. Thawing may also cause
exudation of the nitro-glycerine, which is much more sensitive to shock,
and if accidentally struck with an iron tool, may explode. It is a dangerous
thing to cut a frozen cartridge with a knife. Ramming is even more
dangerous; in fact it is not only dangerous, but wasteful, to use dynamite
when in a frozen state.
Dynamite explodes at a temperature of 360° Fahr., and is very sensitive
to friction when hot. In hot countries it should never be exposed to the rays
of the sun. It should, however, not be kept in a damp or moist place, as this
is liable to cause exudation. Sunlight, if direct, can cause a slow
decomposition, as with all nitro and nitric compounds. Electric sparks
ignite, without exploding it, at least when operating in the open air.
Page 129
Dynamite, when made with neutral nitro-glycerine, appears to keep
indefinitely. Sodium or calcium carbonate to the extent of 1 per cent. is
often added to dynamite to ensure its being neutral. If it has commenced to
undergo change, however, it rapidly becomes acid, and sometimes explodes
spontaneously, especially if contained in resisting envelopes. Nevertheless,
neutral and well-made dynamite has been kept for years in a magazine
without loss of its explosive force. If water is brought into contact with it,
the nitro-glycerine is gradually displaced from the silica (guhr). This action
tends to render all wet dynamite dangerous.
It has been observed that a dynamite made with wood sawdust can be
moistened and then dried without marked alteration, and from 15 to 20 per
cent. of water may be added to cellulose dynamite without depriving it of
the power of exploding by strong detonator (this is similar to wet gun-
cotton). It is, however, rendered much less sensitive to shock. With regard
to the power of No. 1 dynamite, experiments made in lead cylinders give
the relative value of No. 1 dynamite, 1.0; blasting gelatine, 1.4; and nitro-
glycerine, 1.4. The heat liberated by the sudden explosion of dynamite is
the same as its heat of combustion,[A] and proportionate to the weight of
nitro-glycerine contained in the mixture. The gases formed are carbonic
acid, water, nitrogen, and oxygen.
[Footnote A: Berthelot, "Explosives and their Power."]
The "explosive wave" (of Berthelot) for dynamite is about 5,000 metres
per second. At this rate the explosion of a cartridge a foot long would only
occupy 1/24000 part of a second, while a ton of dynamite cartridges about
7/8 diameter, laid end to end, and measuring one mile in length, would be
exploded in one-quarter of a second by detonating a cartridge at either end.
[A] Mr C. Napier Hake, F.I.C., the Inspector of Explosives for the Victorian
Government, in his paper, "Notes on Explosives," says: "The theoretical
indefinitely. Sodium or calcium carbonate to the extent of 1 per cent. is
often added to dynamite to ensure its being neutral. If it has commenced to
undergo change, however, it rapidly becomes acid, and sometimes explodes
spontaneously, especially if contained in resisting envelopes. Nevertheless,
neutral and well-made dynamite has been kept for years in a magazine
without loss of its explosive force. If water is brought into contact with it,
the nitro-glycerine is gradually displaced from the silica (guhr). This action
tends to render all wet dynamite dangerous.
It has been observed that a dynamite made with wood sawdust can be
moistened and then dried without marked alteration, and from 15 to 20 per
cent. of water may be added to cellulose dynamite without depriving it of
the power of exploding by strong detonator (this is similar to wet gun-
cotton). It is, however, rendered much less sensitive to shock. With regard
to the power of No. 1 dynamite, experiments made in lead cylinders give
the relative value of No. 1 dynamite, 1.0; blasting gelatine, 1.4; and nitro-
glycerine, 1.4. The heat liberated by the sudden explosion of dynamite is
the same as its heat of combustion,[A] and proportionate to the weight of
nitro-glycerine contained in the mixture. The gases formed are carbonic
acid, water, nitrogen, and oxygen.
[Footnote A: Berthelot, "Explosives and their Power."]
The "explosive wave" (of Berthelot) for dynamite is about 5,000 metres
per second. At this rate the explosion of a cartridge a foot long would only
occupy 1/24000 part of a second, while a ton of dynamite cartridges about
7/8 diameter, laid end to end, and measuring one mile in length, would be
exploded in one-quarter of a second by detonating a cartridge at either end.
[A] Mr C. Napier Hake, F.I.C., the Inspector of Explosives for the Victorian
Government, in his paper, "Notes on Explosives," says: "The theoretical
Page 130
efficiency of an explosive cannot in practice be realised in useful work for
several reasons, as for instance in blasting rock—
"1. Incomplete combustion.
"2. Compression and chemical changes induced in surrounding material.
"3. Energy expended in cracking and heating of the material which is not
displaced.
"4. The escape of gas through the blast-hole and the fissures caused by
the explosion.
"The useful work consists partly in displacing the shattered masses. The
proportion of useful work obtainable has been variously estimated at from
14 to 33 per cent. of the theoretical maximum potential."
[Footnote A: C.N. Hake, "Notes on Explosives," Jour. Soc. Chem. Ind.,
1889.]
Among the various forms of dynamite that are manufactured is carbo-
dynamite, the invention of Messrs Walter F. Reid and W.D. Borland. The
base is nitro-glycerine, and the absorbent is carbon in the form of burnt
cork. It is as cheap as ordinary dynamite, and has greater explosive force,
seeing that 90 per cent. of the mixture is pure nitro-glycerine, and the
absorbent itself is highly combustible. It is also claimed that if this
dynamite becomes wet, no exudation takes place.
Atlas powder is a dynamite, chiefly manufactured in America at the
Repanno Chemical Works, Philadelphia. It is a composition of nitro-
glycerine, wood-pulp, nitrate of soda, and carbonate of magnesia. This was
the explosive used in the outrages committed in London, by the so-called
several reasons, as for instance in blasting rock—
"1. Incomplete combustion.
"2. Compression and chemical changes induced in surrounding material.
"3. Energy expended in cracking and heating of the material which is not
displaced.
"4. The escape of gas through the blast-hole and the fissures caused by
the explosion.
"The useful work consists partly in displacing the shattered masses. The
proportion of useful work obtainable has been variously estimated at from
14 to 33 per cent. of the theoretical maximum potential."
[Footnote A: C.N. Hake, "Notes on Explosives," Jour. Soc. Chem. Ind.,
1889.]
Among the various forms of dynamite that are manufactured is carbo-
dynamite, the invention of Messrs Walter F. Reid and W.D. Borland. The
base is nitro-glycerine, and the absorbent is carbon in the form of burnt
cork. It is as cheap as ordinary dynamite, and has greater explosive force,
seeing that 90 per cent. of the mixture is pure nitro-glycerine, and the
absorbent itself is highly combustible. It is also claimed that if this
dynamite becomes wet, no exudation takes place.
Atlas powder is a dynamite, chiefly manufactured in America at the
Repanno Chemical Works, Philadelphia. It is a composition of nitro-
glycerine, wood-pulp, nitrate of soda, and carbonate of magnesia. This was
the explosive used in the outrages committed in London, by the so-called
Page 131
"dynamiters." Different varieties contain from 20 to 75 per cent. of nitro-
glycerine.
The Rhenish dynamite, considerably used in the mines of Cornwall, is
composed of 70 parts of a solution of 2 to 3 per cent. of naphthalene in
nitro-glycerine, 3 parts of chalk, 7 parts of sulphate of barium, and 20 of
kieselguhr.
Kieselguhr dynamites are being largely given up in favour of gelatine
explosives. The late Colonel Cundill, in his "Dictionary of Explosives,"
gives a list of about 125 kinds of dynamites. Many of these, however, are
not manufactured. Among the best known after the ordinary No. 1 dynamite
are forcite, ammonia dynamite, litho-fracteur, rendock, Atlas powder, giant
powder, and the various explosive gelatines. They all contain nitro-
glycerine, mixed with a variety of other substances, such as absorbent
earths, wood-pulp, nitro-cotton, carbon in some form or other, nitro- benzol,
paraffin, sulphur, nitrates, or chlorates, &c. &c.
~Blasting Gelatine and Gelatine Dynamite.~—The gelatine explosives
chiefly in use are known under the names of blasting gelatine, gelatine
dynamite, and gelignite. They all consist of the variety of nitro- cellulose
known as collodion-cotton, i.e., a mixture of the penta- and tetra-nitrates
dissolved in nitro-glycerine, and made up with various proportions of
wood-pulp, and some nitrate, or other material of a similar nature. As the
gun-cotton contains too little oxygen for complete combustion, and the
nitro-glycerine an excess, a mixture of the two substances is very beneficial.
Blasting gelatine consists of collodion-cotton and nitro-glycerine without
any other substance, and was patented by Mr Alfred Nobel in 1875. It is a
clear, semi-transparent, jelly-like substance, of a specific gravity of 1.5 to
1.55, slightly elastic, resembling indiarubber, and generally consists of 92
per cent. to 93 per cent. of nitro-glycerine, and 7 to 8 per cent. of nitro-
glycerine.
The Rhenish dynamite, considerably used in the mines of Cornwall, is
composed of 70 parts of a solution of 2 to 3 per cent. of naphthalene in
nitro-glycerine, 3 parts of chalk, 7 parts of sulphate of barium, and 20 of
kieselguhr.
Kieselguhr dynamites are being largely given up in favour of gelatine
explosives. The late Colonel Cundill, in his "Dictionary of Explosives,"
gives a list of about 125 kinds of dynamites. Many of these, however, are
not manufactured. Among the best known after the ordinary No. 1 dynamite
are forcite, ammonia dynamite, litho-fracteur, rendock, Atlas powder, giant
powder, and the various explosive gelatines. They all contain nitro-
glycerine, mixed with a variety of other substances, such as absorbent
earths, wood-pulp, nitro-cotton, carbon in some form or other, nitro- benzol,
paraffin, sulphur, nitrates, or chlorates, &c. &c.
~Blasting Gelatine and Gelatine Dynamite.~—The gelatine explosives
chiefly in use are known under the names of blasting gelatine, gelatine
dynamite, and gelignite. They all consist of the variety of nitro- cellulose
known as collodion-cotton, i.e., a mixture of the penta- and tetra-nitrates
dissolved in nitro-glycerine, and made up with various proportions of
wood-pulp, and some nitrate, or other material of a similar nature. As the
gun-cotton contains too little oxygen for complete combustion, and the
nitro-glycerine an excess, a mixture of the two substances is very beneficial.
Blasting gelatine consists of collodion-cotton and nitro-glycerine without
any other substance, and was patented by Mr Alfred Nobel in 1875. It is a
clear, semi-transparent, jelly-like substance, of a specific gravity of 1.5 to
1.55, slightly elastic, resembling indiarubber, and generally consists of 92
per cent. to 93 per cent. of nitro-glycerine, and 7 to 8 per cent. of nitro-
Page 132
cotton. The cotton from which it is made should be of good quality. The
following is the analysis of a sample of nitro-cellulose which made very
good gelatine:-
Soluble cotton 99.118 per cent.
Gun-cotton 0.642 "
Non-nitrated cotton 0.240 "
Nitrogen 11.64 "
Total ash 0.25 "
The soluble cotton, which is a mixture of the tetra- and penta-nitrates, is
soluble in ether-alcohol, and also in nitro-glycerine, and many other
solvents, whereas the hexa-nitrate (gun-cotton), C_{12}H_{14}O_{4}
(ONO_{2})_{6}, is not soluble in the above liquids, although it is soluble
in acetone or acetic ether. It is very essential, therefore, that the nitro-cotton
used in the manufacture of the gelatine explosives should be as free as
possible from gun-cotton, otherwise little lumps of undissolved nitro-cotton
will be left in the finished gelatine. The non-nitrated or unconverted cotton
should also be very low, in fact considerably under 1/2 per cent.
The nitro-cotton and the nitro-glycerine used should always be tested
before use by the heat test, because if they do not separately stand this test,
it cannot be expected that the gelatine made from them will do so. It often
occurs, however, that although both the ingredients stand this test separately
before being mixed, that after the process of manufacture one or other or
both fail to do so.
The nitro-cotton most suitable for gelatine making is that which has been
finely pulped. If it is not already fine enough, it must be passed through a
fine brass wire sieve. It will be found that it requires to be rubbed through
by hand, and will not go through at all if in the least degree damp. It is
better, therefore, to dry it first. The percentage of nitrogen in the nitrated
following is the analysis of a sample of nitro-cellulose which made very
good gelatine:-
Soluble cotton 99.118 per cent.
Gun-cotton 0.642 "
Non-nitrated cotton 0.240 "
Nitrogen 11.64 "
Total ash 0.25 "
The soluble cotton, which is a mixture of the tetra- and penta-nitrates, is
soluble in ether-alcohol, and also in nitro-glycerine, and many other
solvents, whereas the hexa-nitrate (gun-cotton), C_{12}H_{14}O_{4}
(ONO_{2})_{6}, is not soluble in the above liquids, although it is soluble
in acetone or acetic ether. It is very essential, therefore, that the nitro-cotton
used in the manufacture of the gelatine explosives should be as free as
possible from gun-cotton, otherwise little lumps of undissolved nitro-cotton
will be left in the finished gelatine. The non-nitrated or unconverted cotton
should also be very low, in fact considerably under 1/2 per cent.
The nitro-cotton and the nitro-glycerine used should always be tested
before use by the heat test, because if they do not separately stand this test,
it cannot be expected that the gelatine made from them will do so. It often
occurs, however, that although both the ingredients stand this test separately
before being mixed, that after the process of manufacture one or other or
both fail to do so.
The nitro-cotton most suitable for gelatine making is that which has been
finely pulped. If it is not already fine enough, it must be passed through a
fine brass wire sieve. It will be found that it requires to be rubbed through
by hand, and will not go through at all if in the least degree damp. It is
better, therefore, to dry it first. The percentage of nitrogen in the nitrated
Page 133
cotton should be over 11 per cent. It should be as free as possible from sand
or grit, and should give but little ash upon ignition, not more than 0.25 per
cent. The cotton, which is generally packed wet in zinc-lined wooden
boxes, will require to be dried, as it is very essential indeed that none of the
materials used in the manufacture of gelatine should contain more than the
slightest trace of water. If they do, the gelatine subsequently made from
them will most certainly exude, and become dangerous and comparatively
valueless. It will also be much more difficult to make the nitro-cotton
dissolve in the nitro-glycerine if either contains water.
In order to find out how long any sample of cotton requires to be dried, a
sample should be taken from the centre of several boxes, well mixed, and
about 1,000 grms. spread out on a paper tray, weighed, and the whole then
placed in the water oven at 100° C., and dried for an hour or so, and again
weighed, and the percentage of moisture calculated from the loss in weight.
This will be a guide to the time that the cotton will probably require to be in
the drying house. Samples generally contain from 20 to 30 per cent. of
water. After drying for a period of forty-eight hours, a sample should be
again dried in the oven at 100° C., and the moisture determined, and so on
at intervals until the bulk of the cotton is found to be dry, i.e., to contain
from 0.25 to 0.5 per cent. of moisture. It is then ready to be sifted. During
the process of removing to the sifting house and the sifting itself, the cotton
should be exposed to the air as little as possible, as dry nitro-cotton absorbs
as much as 2 per cent. of moisture from the air at ordinary temperatures and
average dryness.
The drying house usually consists of a wooden building, the inside of
which is fitted with shelves, or rather framework to contain drawers, made
of wood, with brass or copper wire netting bottoms. A current of hot air is
made to pass through the shelves and over the surface of the cotton, which
is spread out upon them to the depth of about 2 inches. This current of air
or grit, and should give but little ash upon ignition, not more than 0.25 per
cent. The cotton, which is generally packed wet in zinc-lined wooden
boxes, will require to be dried, as it is very essential indeed that none of the
materials used in the manufacture of gelatine should contain more than the
slightest trace of water. If they do, the gelatine subsequently made from
them will most certainly exude, and become dangerous and comparatively
valueless. It will also be much more difficult to make the nitro-cotton
dissolve in the nitro-glycerine if either contains water.
In order to find out how long any sample of cotton requires to be dried, a
sample should be taken from the centre of several boxes, well mixed, and
about 1,000 grms. spread out on a paper tray, weighed, and the whole then
placed in the water oven at 100° C., and dried for an hour or so, and again
weighed, and the percentage of moisture calculated from the loss in weight.
This will be a guide to the time that the cotton will probably require to be in
the drying house. Samples generally contain from 20 to 30 per cent. of
water. After drying for a period of forty-eight hours, a sample should be
again dried in the oven at 100° C., and the moisture determined, and so on
at intervals until the bulk of the cotton is found to be dry, i.e., to contain
from 0.25 to 0.5 per cent. of moisture. It is then ready to be sifted. During
the process of removing to the sifting house and the sifting itself, the cotton
should be exposed to the air as little as possible, as dry nitro-cotton absorbs
as much as 2 per cent. of moisture from the air at ordinary temperatures and
average dryness.
The drying house usually consists of a wooden building, the inside of
which is fitted with shelves, or rather framework to contain drawers, made
of wood, with brass or copper wire netting bottoms. A current of hot air is
made to pass through the shelves and over the surface of the cotton, which
is spread out upon them to the depth of about 2 inches. This current of air
Page 134
can be obtained in any way that may be found convenient, such as by means
of a fan or Root's blower, the air being passed over hot bricks, or hot-water
pipes before entering the building. The cotton should also be occasionally
turned over by hand in order that a fresh surface may be continually
exposed to the action of the hot air. The building itself may be heated by
means of hot-water pipes, but on no account should any of the pipes be
exposed. They should all be most carefully covered over with wood-work,
because when the dry nitro-cotton is moved, as in turning it over, very fine
particles get into the air, and gradually settling on the pipes, window ledges,
&c., may become very hot, when the slightest friction might cause
explosion. It is on this account that this house should be very carefully
swept out every day. It is also very desirable that the floor of this house
should be covered with oilcloth or linoleum, as being soft, it lessens the
friction.
List shoes should always be worn in this building, and a thermometer
hung up somewhere about the centre of the house, and one should also be
kept in one of the trays to give the temperature of the cotton, especially the
bottom of the trays. The one nearest to the hot air inlet should be selected. If
the temperature of the house is kept at about 40° C. it will be quite high
enough. The building must of course be properly ventilated, and it will be
found very useful to have the walls made double, and the intervening space
filled with cinders, and the roof covered with felt, as this helps to prevent
the loss of heat through radiation, and to preserve a uniform temperature,
which is very desirable.
The dry cotton thus obtained, if not already fine enough, should be sifted
through a brass sieve, and packed away ready for use in zinc air-tight cases,
or in indiarubber bags. The various gelatine compounds, gelignite, gelatine
dynamite, and blasting gelatine, are manufactured in exactly the same way.
The forms known as gelatine dynamite differ from blasting gelatine in
of a fan or Root's blower, the air being passed over hot bricks, or hot-water
pipes before entering the building. The cotton should also be occasionally
turned over by hand in order that a fresh surface may be continually
exposed to the action of the hot air. The building itself may be heated by
means of hot-water pipes, but on no account should any of the pipes be
exposed. They should all be most carefully covered over with wood-work,
because when the dry nitro-cotton is moved, as in turning it over, very fine
particles get into the air, and gradually settling on the pipes, window ledges,
&c., may become very hot, when the slightest friction might cause
explosion. It is on this account that this house should be very carefully
swept out every day. It is also very desirable that the floor of this house
should be covered with oilcloth or linoleum, as being soft, it lessens the
friction.
List shoes should always be worn in this building, and a thermometer
hung up somewhere about the centre of the house, and one should also be
kept in one of the trays to give the temperature of the cotton, especially the
bottom of the trays. The one nearest to the hot air inlet should be selected. If
the temperature of the house is kept at about 40° C. it will be quite high
enough. The building must of course be properly ventilated, and it will be
found very useful to have the walls made double, and the intervening space
filled with cinders, and the roof covered with felt, as this helps to prevent
the loss of heat through radiation, and to preserve a uniform temperature,
which is very desirable.
The dry cotton thus obtained, if not already fine enough, should be sifted
through a brass sieve, and packed away ready for use in zinc air-tight cases,
or in indiarubber bags. The various gelatine compounds, gelignite, gelatine
dynamite, and blasting gelatine, are manufactured in exactly the same way.
The forms known as gelatine dynamite differ from blasting gelatine in
Page 135
containing certain proportions of wood-pulp and potassium nitrate, &c. The
following are analyses of some typical samples of the three compounds:—
Gelatine Blasting
Gelignite. Dynamite. Gelatine.
Nitro-glycerine 60.514 71.128 92.94 per cent.
Nitro-cellulose 4.888 7.632 7.06 "
Wood-pulp 7.178 4.259 … "
Potassium nitrate 27.420 16.720 … "
Water … 0.261 … "
The gelignite and gelatine dynamites consist, therefore, of blasting
gelatine, thickened up with a mixture of absorbing materials. Although the
blasting gelatine is weight for weight more powerful, it is more difficult to
make than either of the other two compounds, it being somewhat difficult to
make it stand the exudation and melting tests. The higher percentage of
nitro-cotton, too, makes it expensive.
When the dry nitro-cotton, which has been carefully weighed out in the
proportions necessary either for blasting gelatine or any of the other
gelatine explosives, is brought to the gelatine making house, it is placed in a
lead-lined trough, and the necessary quantity of pure dry nitro- glycerine
poured upon it. The whole is then well stirred up, and kept at a temperature
of from 40° to 45° C. It should not be allowed to go much above 40° C.; but
higher temperatures may be used if the nitro-cotton is very obstinate,[A]
and will not dissolve. Great caution must, however, be observed in this
case. The mixture should be constantly worked about by the workman with
a wooden paddle for at least half an hour. At a temperature of 40° to 45° the
nitro-glycerine acts upon the nitro-cotton and forms a jelly. Without heat the
gelatinisation is very imperfect indeed, and at temperatures under 40° C.
takes place very slowly.
following are analyses of some typical samples of the three compounds:—
Gelatine Blasting
Gelignite. Dynamite. Gelatine.
Nitro-glycerine 60.514 71.128 92.94 per cent.
Nitro-cellulose 4.888 7.632 7.06 "
Wood-pulp 7.178 4.259 … "
Potassium nitrate 27.420 16.720 … "
Water … 0.261 … "
The gelignite and gelatine dynamites consist, therefore, of blasting
gelatine, thickened up with a mixture of absorbing materials. Although the
blasting gelatine is weight for weight more powerful, it is more difficult to
make than either of the other two compounds, it being somewhat difficult to
make it stand the exudation and melting tests. The higher percentage of
nitro-cotton, too, makes it expensive.
When the dry nitro-cotton, which has been carefully weighed out in the
proportions necessary either for blasting gelatine or any of the other
gelatine explosives, is brought to the gelatine making house, it is placed in a
lead-lined trough, and the necessary quantity of pure dry nitro- glycerine
poured upon it. The whole is then well stirred up, and kept at a temperature
of from 40° to 45° C. It should not be allowed to go much above 40° C.; but
higher temperatures may be used if the nitro-cotton is very obstinate,[A]
and will not dissolve. Great caution must, however, be observed in this
case. The mixture should be constantly worked about by the workman with
a wooden paddle for at least half an hour. At a temperature of 40° to 45° the
nitro-glycerine acts upon the nitro-cotton and forms a jelly. Without heat the
gelatinisation is very imperfect indeed, and at temperatures under 40° C.
takes place very slowly.
Page 136
[Footnote A: Generally due to the nitro-cotton being damp.]
[Illustration: FIG. 30.—WERNER, PFLEIDERER, & PERKINS'
MIXING MACHINE.]
The limit of temperature is 50° C. or thereabouts. Beyond this the jelly
should never be allowed to go, and to 50° only under exceptional
circumstances.
The tank in which the jelly is made is double-lined, in order to allow of
the passage of hot water between its inner and outer linings. A series of such
tanks are generally built in a wooden framework, and the double linings are
made to communicate, so that the hot water can flow from one to the other
consecutively. The temperature of the water should be about 60° C. if it is
intended to gelatinise at 45° C., and about 80° if at 50° C.; but this point
must, of course, be found by experiment for the particular plant used. An
arrangement should be made to enable the workman to at once cut off the
supply of hot water and pass cold water through the tanks in case the
explosive becomes too hot.
[Illustration: FIG. 31.—MR M'ROBERTS' MIXER FOR GELATINE
EXPLOSIVES.]
The best way to keep the temperature of the water constant is to have a
large tank of water raised upon a platform, some 5 or 6 feet high, outside
the building, which is automatically supplied with water, and into which
steam is turned. A thermometer stuck through a piece of cork and floated
upon the surface of the tank will give the means of regulating the
temperature.
When the jelly in the tanks has become semi-transparent and the cotton
has entirely dissolved, the mixture should be transferred to the mixing
[Illustration: FIG. 30.—WERNER, PFLEIDERER, & PERKINS'
MIXING MACHINE.]
The limit of temperature is 50° C. or thereabouts. Beyond this the jelly
should never be allowed to go, and to 50° only under exceptional
circumstances.
The tank in which the jelly is made is double-lined, in order to allow of
the passage of hot water between its inner and outer linings. A series of such
tanks are generally built in a wooden framework, and the double linings are
made to communicate, so that the hot water can flow from one to the other
consecutively. The temperature of the water should be about 60° C. if it is
intended to gelatinise at 45° C., and about 80° if at 50° C.; but this point
must, of course, be found by experiment for the particular plant used. An
arrangement should be made to enable the workman to at once cut off the
supply of hot water and pass cold water through the tanks in case the
explosive becomes too hot.
[Illustration: FIG. 31.—MR M'ROBERTS' MIXER FOR GELATINE
EXPLOSIVES.]
The best way to keep the temperature of the water constant is to have a
large tank of water raised upon a platform, some 5 or 6 feet high, outside
the building, which is automatically supplied with water, and into which
steam is turned. A thermometer stuck through a piece of cork and floated
upon the surface of the tank will give the means of regulating the
temperature.
When the jelly in the tanks has become semi-transparent and the cotton
has entirely dissolved, the mixture should be transferred to the mixing
Page 137
machine. The mixing machines are specially designed for this work, and are
built in iron, with steel or bronze kneading- and mixing-blades, according to
requirements.
A suitable machine for the purpose is that known as the Nito-Universal
Incorporator, shown in Fig. 30, which has been specially constructed by
Messrs Werner, Pfleiderer, & Perkins, Ltd., after many years' experience in
the mixing of explosive materials, and is now almost exclusively adopted in
both Government and private factories. Mr George M'Roberts'[A] mixing
machine, however, which is shown in Fig. 31, is still used in some factories
for dynamite jelly.
[Footnote A: See Jour. Soc. Chem. Ind., 1890, 267.]
If it is intended to make gelignite, or gelatine dynamite, it is at this point
that the proper proportions of wood-pulp[A] and potassium nitrate should
be added, and the whole well mixed for at least half an hour, until the
various ingredients are thoroughly incorporated.
[Footnote A: Most of the wood-pulp used in England is obtained from
pine-trees, but poplar, lime, birch, and beech wood are also used. It is
chiefly imported as wood-pulp. The pulp is prepared as follows:—The bark
and roots are first removed, and the logs then sawn into boards, from which
the knots are removed. The pieces of wood are afterwards put through a
machine which breaks them up into small pieces about an inch long, which
are then crushed between rollers. These fragments are finally boiled with a
solution of sodium bisulphite, under a pressure of about 90 lbs. per square
inch, the duration of the boiling being from ten to twelve hours. Sulphurous
acid has also been used. Pine-wood yields about 45 per cent. and birch
about 40 per cent. of pulp when treated by this process. The pulp is
afterwards bleached and washed, &c.
built in iron, with steel or bronze kneading- and mixing-blades, according to
requirements.
A suitable machine for the purpose is that known as the Nito-Universal
Incorporator, shown in Fig. 30, which has been specially constructed by
Messrs Werner, Pfleiderer, & Perkins, Ltd., after many years' experience in
the mixing of explosive materials, and is now almost exclusively adopted in
both Government and private factories. Mr George M'Roberts'[A] mixing
machine, however, which is shown in Fig. 31, is still used in some factories
for dynamite jelly.
[Footnote A: See Jour. Soc. Chem. Ind., 1890, 267.]
If it is intended to make gelignite, or gelatine dynamite, it is at this point
that the proper proportions of wood-pulp[A] and potassium nitrate should
be added, and the whole well mixed for at least half an hour, until the
various ingredients are thoroughly incorporated.
[Footnote A: Most of the wood-pulp used in England is obtained from
pine-trees, but poplar, lime, birch, and beech wood are also used. It is
chiefly imported as wood-pulp. The pulp is prepared as follows:—The bark
and roots are first removed, and the logs then sawn into boards, from which
the knots are removed. The pieces of wood are afterwards put through a
machine which breaks them up into small pieces about an inch long, which
are then crushed between rollers. These fragments are finally boiled with a
solution of sodium bisulphite, under a pressure of about 90 lbs. per square
inch, the duration of the boiling being from ten to twelve hours. Sulphurous
acid has also been used. Pine-wood yields about 45 per cent. and birch
about 40 per cent. of pulp when treated by this process. The pulp is
afterwards bleached and washed, &c.
Page 138
Birch. Beech. Lime. Pine. Poplar.
Cellulose 55.52 45.47 53.09 56.99 62.77 per cent.
Resin 1.14 0.41 3.93 0.97 1.37 "
Aqueous extract 2.65 2.47 3.56 1.26 2.88 "
Water 12.48 12.57 10.10 13.87 12.10 "
Lignine 28.21 39.14 29.32 26.91 20.88 "]
The following analysis of woods is by Dr H. Müller:—These mixing
machines can either be turned by hand, or a shaft can be brought into the
house and the machine worked by means of a belt at twenty to thirty
revolutions per minute. The bearings should be kept constantly greased and
examined, and the explosive mixture carefully excluded. When the gelatine
mixture has been thoroughly incorporated, and neither particles of nitrate or
wood meal can be detected in the mass, it should be transferred to wooden
boxes and carried away to the cartridge-making machines to be worked up
into cartridges.
[Illustration: FIG. 32.—PLAN OF THE BOX CONTAINING THE
EXPLOSIVE, IN
M'ROBERTS' MACHINE.]
The application of heat in the manufacture of the jelly from collodion-
cotton and nitro-glycerine is absolutely necessary, unless some other
solvent is used besides the nitro-glycerine, such as acetone, acetic ether,
methyl, or ethyl-alcohol. (They are all too expensive, with the exception of
acetone and methyl-alcohol, for use upon the large scale.) These liquids not
only dissolve the nitro-cellulose in the cold, but render the resulting gelatine
compound less sensitive to concussion, and reduce its quickness of
explosion (as in cordite). They also lower the temperature at which the
nitro-glycerine becomes congealed, i.e., they lower the freezing point[A] of
the resulting gelatine.
Cellulose 55.52 45.47 53.09 56.99 62.77 per cent.
Resin 1.14 0.41 3.93 0.97 1.37 "
Aqueous extract 2.65 2.47 3.56 1.26 2.88 "
Water 12.48 12.57 10.10 13.87 12.10 "
Lignine 28.21 39.14 29.32 26.91 20.88 "]
The following analysis of woods is by Dr H. Müller:—These mixing
machines can either be turned by hand, or a shaft can be brought into the
house and the machine worked by means of a belt at twenty to thirty
revolutions per minute. The bearings should be kept constantly greased and
examined, and the explosive mixture carefully excluded. When the gelatine
mixture has been thoroughly incorporated, and neither particles of nitrate or
wood meal can be detected in the mass, it should be transferred to wooden
boxes and carried away to the cartridge-making machines to be worked up
into cartridges.
[Illustration: FIG. 32.—PLAN OF THE BOX CONTAINING THE
EXPLOSIVE, IN
M'ROBERTS' MACHINE.]
The application of heat in the manufacture of the jelly from collodion-
cotton and nitro-glycerine is absolutely necessary, unless some other
solvent is used besides the nitro-glycerine, such as acetone, acetic ether,
methyl, or ethyl-alcohol. (They are all too expensive, with the exception of
acetone and methyl-alcohol, for use upon the large scale.) These liquids not
only dissolve the nitro-cellulose in the cold, but render the resulting gelatine
compound less sensitive to concussion, and reduce its quickness of
explosion (as in cordite). They also lower the temperature at which the
nitro-glycerine becomes congealed, i.e., they lower the freezing point[A] of
the resulting gelatine.
Page 139
[Footnote A: It has been proposed to mix dynamite with amyl alcohol for
this purpose. Di-nitro-mono-chlorhydrine has also been proposed.]
The finished gelatine paste, upon entering the cartridge huts, is at once
transferred to the cartridge-making machine, which is very like an ordinary
sausage-making machine[A] (Fig. 33). The whole thing must be made of
gun-metal or brass, and it consists of a conical case containing a shaft and
screw. The revolutions of the shaft cause the thread of the screw to push
forward the gelatine introduced by the hopper on the top to the nozzle, the
apex of the cone-shaped case, from whence the gelatine issues as a
continuous rope. The nozzle is of course of a diameter according to the size
of cartridge required.
[Footnote A: G. M'Roberts, Jour. Soc. Chem. Ind., 31st March 1890, p.
266.]
[Illustration: FIG. 33.—CARTRIDGE-MAKING MACHINE FOR
GELATINE
EXPLOSIVES.]
The issuing gelatine can of course be cut off at any length. This is best
done with a piece of hard wood planed down to a cutting edge, i.e., wedge-
shaped. Mr Trench has devised a kind of brass frame, into which the
gelatine issuing from the nozzle of the cartridge machine is forced, finding
its way along a series of grooves. When the frame is full, a wooden frame,
which is hinged to one end of the bottom frame, and fitted with a series of
brass knives, is shut down, thereby cutting the gelatine up into lengths of
about 4 inches.
It is essential that the cartridge machines should have no metallic
contacts inside. The bearing for the screw shaft must be fixed outside the
cone containing the gelatine. One of these machines can convert from 5 to
this purpose. Di-nitro-mono-chlorhydrine has also been proposed.]
The finished gelatine paste, upon entering the cartridge huts, is at once
transferred to the cartridge-making machine, which is very like an ordinary
sausage-making machine[A] (Fig. 33). The whole thing must be made of
gun-metal or brass, and it consists of a conical case containing a shaft and
screw. The revolutions of the shaft cause the thread of the screw to push
forward the gelatine introduced by the hopper on the top to the nozzle, the
apex of the cone-shaped case, from whence the gelatine issues as a
continuous rope. The nozzle is of course of a diameter according to the size
of cartridge required.
[Footnote A: G. M'Roberts, Jour. Soc. Chem. Ind., 31st March 1890, p.
266.]
[Illustration: FIG. 33.—CARTRIDGE-MAKING MACHINE FOR
GELATINE
EXPLOSIVES.]
The issuing gelatine can of course be cut off at any length. This is best
done with a piece of hard wood planed down to a cutting edge, i.e., wedge-
shaped. Mr Trench has devised a kind of brass frame, into which the
gelatine issuing from the nozzle of the cartridge machine is forced, finding
its way along a series of grooves. When the frame is full, a wooden frame,
which is hinged to one end of the bottom frame, and fitted with a series of
brass knives, is shut down, thereby cutting the gelatine up into lengths of
about 4 inches.
It is essential that the cartridge machines should have no metallic
contacts inside. The bearing for the screw shaft must be fixed outside the
cone containing the gelatine. One of these machines can convert from 5 to
Page 140
10 cwt. of gelatine into cartridges per diem, depending upon the diameter of
the cartridges made.
After being cut up into lengths of about 3 inches, the gelatine is rolled up
in cartridge paper. Waterproof paper is generally used. The cartridges are
then packed away in cardboard boxes, which are again packed in deal boxes
lined with indiarubber, and screwed down air tight, brass screws or zinc or
brass nails being used for the purpose. These boxes are sent to the
magazines. Before the boxes are fastened down a cartridge or so should be
removed and tested by the heat test, the liquefaction test, and the test for
liability to exudation. (Appendix, p. 6, Explosives Act, 1875.) A cartridge
also should be stored in the magazine in case of any subsequent dispute
after the bulk of the material has left the factory.
The object of the liquefaction test is to ensure that the gelatine shall be
able to withstand a fairly high temperature (such as it might encounter in a
ship's hold) without melting or running together. The test is carried out as
follows:—A cylinder of the gelatine dynamite is cut from the cartridge of a
length equal to its diameter. The edges must be sharp. This cylinder is to be
placed on end on a flat surface (such as paper), and secured by a pin
through the centre, and exposed for 144 consecutive hours to a temperature
of 85° to 90° F., and during such time the cylinder should not diminish in
height by more than one-fourth of an inch, and the cut edges should remain
sharp. There should also be no stain of nitroglycerine upon the paper.
The exudation test consists in freezing and thawing the gelatine three
times in succession. Under these conditions there should be no exudation of
nitro-glycerine. All the materials used in the manufacture of gelatine
explosives should be subjected to analytical examination before use, as
success largely depends upon the purity of the raw materials. The wood-
pulp, for instance, must be examined for acidity.
the cartridges made.
After being cut up into lengths of about 3 inches, the gelatine is rolled up
in cartridge paper. Waterproof paper is generally used. The cartridges are
then packed away in cardboard boxes, which are again packed in deal boxes
lined with indiarubber, and screwed down air tight, brass screws or zinc or
brass nails being used for the purpose. These boxes are sent to the
magazines. Before the boxes are fastened down a cartridge or so should be
removed and tested by the heat test, the liquefaction test, and the test for
liability to exudation. (Appendix, p. 6, Explosives Act, 1875.) A cartridge
also should be stored in the magazine in case of any subsequent dispute
after the bulk of the material has left the factory.
The object of the liquefaction test is to ensure that the gelatine shall be
able to withstand a fairly high temperature (such as it might encounter in a
ship's hold) without melting or running together. The test is carried out as
follows:—A cylinder of the gelatine dynamite is cut from the cartridge of a
length equal to its diameter. The edges must be sharp. This cylinder is to be
placed on end on a flat surface (such as paper), and secured by a pin
through the centre, and exposed for 144 consecutive hours to a temperature
of 85° to 90° F., and during such time the cylinder should not diminish in
height by more than one-fourth of an inch, and the cut edges should remain
sharp. There should also be no stain of nitroglycerine upon the paper.
The exudation test consists in freezing and thawing the gelatine three
times in succession. Under these conditions there should be no exudation of
nitro-glycerine. All the materials used in the manufacture of gelatine
explosives should be subjected to analytical examination before use, as
success largely depends upon the purity of the raw materials. The wood-
pulp, for instance, must be examined for acidity.
Page 141
~Properties of the Gelatine Compounds.~—Blasting gelatine is generally
composed of 93 to 95 parts nitro-glycerine, and 5 to 7 parts of nitro-
cellulose, but the relative proportions of explosive base and nitro- glycerine,
&c., in the various forms of the gelatine explosives do not always
correspond to those necessary for total combustion, either because an
incomplete combustion gives rise to a greater volume of gas, or because the
rapidity of decomposition and the law of expansion varies according to the
relative proportions and the conditions of application. The various additions
to blasting gelatine generally have the effect of lowering the strength by
reducing the amount of nitro-glycerine, but this is sometimes done in order
to change a shattering agent into a propulsive force. If this process be
carried too far, we of course lose the advantages due to the presence of
nitro-glycerine. There is therefore a limit to these additions.[A]
[Footnote A: Mica is said to increase the rapidity of explosion when
mixed with gelatine.]
The homogeneousness and stability of the mixture are of the highest
importance. It is highly essential that the nitro-glycerine should be
completely absorbed by the substances with which it is mixed, and that it
should not subsequently exude when subjected to heat or damp. It is also
important that there should be no excess of nitro-glycerine, as this may
diminish instead of augment the strength, owing to a difference in the mode
of the propagation of the explosive wave in the liquid, and in the mixture.
Nitro-glycerine at its freezing point has a tendency to separate from its
absorbing material, in fact to exude. When frozen, too, it requires a more
powerful detonation to explode it, but it is less sensitive to shock. The
specific gravity of blasting gelatine is 1.5 (i.e., nearly equal to that of nitro-
glycerol); that of gun-cotton (dry) is 1.0.
composed of 93 to 95 parts nitro-glycerine, and 5 to 7 parts of nitro-
cellulose, but the relative proportions of explosive base and nitro- glycerine,
&c., in the various forms of the gelatine explosives do not always
correspond to those necessary for total combustion, either because an
incomplete combustion gives rise to a greater volume of gas, or because the
rapidity of decomposition and the law of expansion varies according to the
relative proportions and the conditions of application. The various additions
to blasting gelatine generally have the effect of lowering the strength by
reducing the amount of nitro-glycerine, but this is sometimes done in order
to change a shattering agent into a propulsive force. If this process be
carried too far, we of course lose the advantages due to the presence of
nitro-glycerine. There is therefore a limit to these additions.[A]
[Footnote A: Mica is said to increase the rapidity of explosion when
mixed with gelatine.]
The homogeneousness and stability of the mixture are of the highest
importance. It is highly essential that the nitro-glycerine should be
completely absorbed by the substances with which it is mixed, and that it
should not subsequently exude when subjected to heat or damp. It is also
important that there should be no excess of nitro-glycerine, as this may
diminish instead of augment the strength, owing to a difference in the mode
of the propagation of the explosive wave in the liquid, and in the mixture.
Nitro-glycerine at its freezing point has a tendency to separate from its
absorbing material, in fact to exude. When frozen, too, it requires a more
powerful detonation to explode it, but it is less sensitive to shock. The
specific gravity of blasting gelatine is 1.5 (i.e., nearly equal to that of nitro-
glycerol); that of gun-cotton (dry) is 1.0.
Page 142
Blasting gelatine burns in the air when unconfined without explosion, at
least in small quantities and when not previously heated, but it is rather
uncertain in this respect. It can be kept at a moderately high temperature
(70° C.) without decomposition. At higher temperatures the nitro-glycerine
will partially evaporate. When slowly heated, it explodes at 204° C. If,
however, it contains as much as 10 per cent. of camphor, it burns without
exploding. According to Berthelot,[A] gelatine composed of 91.6 per cent.
nitro-glycerine and 8.4 per cent. of nitro-cellulose, which are the
proportions corresponding to total combustion, produces by explosion
177CO_{2}+ 143H_{2}O + 8N_{2}.
[Footnote A: Berthelot, "Explosives and their Powers."]
He takes C_{24}H_{22}(NO_{3}H){9}O{11} as the formula of the
nitro- cellulose, and 51C_{3}H_{2}(NO_{3}H){3} + C{24}H_{22}
(NO_{3}H){9}O{11} as the formula of the gelatine itself, its equivalent
weight being 12,360 grms. The heat liberated by its explosion is equal to
19,381 calories, or for 1 kilo. 1,535 calories. Volume of gases reduced
temperature equals 8,950 litres. The relative value[A] of blasting gelatine to
nitro- glycerine is as 1.4 to 1.45, kieselguhr dynamite being taken as 1.0.
[Footnote A: Roux and Sarran.]
least in small quantities and when not previously heated, but it is rather
uncertain in this respect. It can be kept at a moderately high temperature
(70° C.) without decomposition. At higher temperatures the nitro-glycerine
will partially evaporate. When slowly heated, it explodes at 204° C. If,
however, it contains as much as 10 per cent. of camphor, it burns without
exploding. According to Berthelot,[A] gelatine composed of 91.6 per cent.
nitro-glycerine and 8.4 per cent. of nitro-cellulose, which are the
proportions corresponding to total combustion, produces by explosion
177CO_{2}+ 143H_{2}O + 8N_{2}.
[Footnote A: Berthelot, "Explosives and their Powers."]
He takes C_{24}H_{22}(NO_{3}H){9}O{11} as the formula of the
nitro- cellulose, and 51C_{3}H_{2}(NO_{3}H){3} + C{24}H_{22}
(NO_{3}H){9}O{11} as the formula of the gelatine itself, its equivalent
weight being 12,360 grms. The heat liberated by its explosion is equal to
19,381 calories, or for 1 kilo. 1,535 calories. Volume of gases reduced
temperature equals 8,950 litres. The relative value[A] of blasting gelatine to
nitro- glycerine is as 1.4 to 1.45, kieselguhr dynamite being taken as 1.0.
[Footnote A: Roux and Sarran.]
Page 143
CHAPTER V.
NITRO-BENZOL, ROBURITE, BELLITE, PICRIC ACID, &c.
Explosives derived from Benzene—Toluene and Nitro-Benzene—Di-
and
Tri-nitro-Benzene—Roburite: Properties and Manufacture—Bellite:
Properties, &c.—Securite—Tonite No. 3.—Nitro-Toluene—
Nitro-Naphthalene—Ammonite—Sprengel's Explosives—Picric Acid—
Picrates—Picric Powders—Melinite—Abel's Mixture—Brugère's Powders
—
The Fulminates—Composition, Formula, Preparation, Danger of, &c.—
Detonators: Sizes, Composition, Manufacture—Fuses, &c.
~The Explosives derived from Benzene.~—There is a large class of
explosives made from the nitrated hydro-carbons—benzene, C_{6}H_{6};
toluene, C_{7}H_{8}; naphthalene, C_{10}H_{8}; and also from phenol
(or carbolic acid), C_{6}H_{5}OH. The benzene hydro-carbons are
generally colourless liquids, insoluble in water, but soluble in alcohol and
ether. They generally distil without decomposition. They burn with a smoky
flame, and have an ethereal odour. They are easily nitrated and sulphurated;
mono, di, and tri derivatives are readily prepared, according to the strength
of the acids used. It is only the H-atoms of the benzene nucleus which enter
into reaction.
NITRO-BENZOL, ROBURITE, BELLITE, PICRIC ACID, &c.
Explosives derived from Benzene—Toluene and Nitro-Benzene—Di-
and
Tri-nitro-Benzene—Roburite: Properties and Manufacture—Bellite:
Properties, &c.—Securite—Tonite No. 3.—Nitro-Toluene—
Nitro-Naphthalene—Ammonite—Sprengel's Explosives—Picric Acid—
Picrates—Picric Powders—Melinite—Abel's Mixture—Brugère's Powders
—
The Fulminates—Composition, Formula, Preparation, Danger of, &c.—
Detonators: Sizes, Composition, Manufacture—Fuses, &c.
~The Explosives derived from Benzene.~—There is a large class of
explosives made from the nitrated hydro-carbons—benzene, C_{6}H_{6};
toluene, C_{7}H_{8}; naphthalene, C_{10}H_{8}; and also from phenol
(or carbolic acid), C_{6}H_{5}OH. The benzene hydro-carbons are
generally colourless liquids, insoluble in water, but soluble in alcohol and
ether. They generally distil without decomposition. They burn with a smoky
flame, and have an ethereal odour. They are easily nitrated and sulphurated;
mono, di, and tri derivatives are readily prepared, according to the strength
of the acids used. It is only the H-atoms of the benzene nucleus which enter
into reaction.
Page 144
Benzene was discovered by Faraday in 1825, and detected in coal-tar by
Hofmann in 1845. It can be obtained from that portion of coal-tar which
boils at 80° to 85° by fractionating or freezing.[A] The ordinary benzene of
commerce contains thiophene (C_{4}H_{4}S), from which it may be freed
by shaking with sulphuric acid. Its boiling point is 79° C.; specific gravity
at 0° equals 0.9. It burns with a luminous smoky flame, and is a good
solvent for fats, resins, sulphur, phosphorus, &c. Toluene was discovered in
1837, and is prepared from coal-tar. It boils at 110° C., and is still liquid at
28° C.
[Footnote A: It may be prepared chemically pure by distilling a mixture
of benzoic acid and lime.]
The mono-, chloro-, bromo-, and iodo-benzenes are colourless liquids of
peculiar odour. Di-chloro-, di-bromo-benzenes, tri- and hexa-chloro- and
bromo-benzenes, are also known; and mono-chloro-,
C_{6}H_{4}Cl(CH_{3}), and bromo-toluenes, together with di derivatives
in the ortho, meta, and para modifications. The nitro-benzenes and toluenes
are used as explosives. The following summary is taken from Dr A.
Bernthsen's "Organic Chemistry":—
SUMMARY.
_____________________________________________________________
_______ | | | C_{6}H_{5}(N0_{2}) Nitro-benzene. Liq. B.Pt. 206° C. | | | |
C_{6}H_{4}(NO_{2}){2} Ortho-, meta-, and para- di-nitro-benzenes. | |
Solid. M.P. 118°, 90°, and 172° C. | | | | C{6}H_{3}(NO_{3})_{3} S.-Tri-
nitro-benzene. Solid. M.P. 121° C. |
|____________________________________________________________
________| | | | C_{6}H_{4}(CH_{3})NO_{2} Ortho-, meta-, and para-
nitro-toluenes. | | B.P. 218°, 230°, and 234° C, Para compound solid. |
|____________________________________________________________
Hofmann in 1845. It can be obtained from that portion of coal-tar which
boils at 80° to 85° by fractionating or freezing.[A] The ordinary benzene of
commerce contains thiophene (C_{4}H_{4}S), from which it may be freed
by shaking with sulphuric acid. Its boiling point is 79° C.; specific gravity
at 0° equals 0.9. It burns with a luminous smoky flame, and is a good
solvent for fats, resins, sulphur, phosphorus, &c. Toluene was discovered in
1837, and is prepared from coal-tar. It boils at 110° C., and is still liquid at
28° C.
[Footnote A: It may be prepared chemically pure by distilling a mixture
of benzoic acid and lime.]
The mono-, chloro-, bromo-, and iodo-benzenes are colourless liquids of
peculiar odour. Di-chloro-, di-bromo-benzenes, tri- and hexa-chloro- and
bromo-benzenes, are also known; and mono-chloro-,
C_{6}H_{4}Cl(CH_{3}), and bromo-toluenes, together with di derivatives
in the ortho, meta, and para modifications. The nitro-benzenes and toluenes
are used as explosives. The following summary is taken from Dr A.
Bernthsen's "Organic Chemistry":—
SUMMARY.
_____________________________________________________________
_______ | | | C_{6}H_{5}(N0_{2}) Nitro-benzene. Liq. B.Pt. 206° C. | | | |
C_{6}H_{4}(NO_{2}){2} Ortho-, meta-, and para- di-nitro-benzenes. | |
Solid. M.P. 118°, 90°, and 172° C. | | | | C{6}H_{3}(NO_{3})_{3} S.-Tri-
nitro-benzene. Solid. M.P. 121° C. |
|____________________________________________________________
________| | | | C_{6}H_{4}(CH_{3})NO_{2} Ortho-, meta-, and para-
nitro-toluenes. | | B.P. 218°, 230°, and 234° C, Para compound solid. |
|____________________________________________________________
Page 145
________| | | | C_{6}H_{3}(CH_{3}){2}NO{2} Nitro-xylene. Liquid. |
|____________________________________________________________
________| | | | C_{6}H_{2}(CH_{3}){3}NO{2} Nitro-mesitylene. Solid. |
|____________________________________________________________
________| | | | C_{6}H_{3}(CH_{3})(NO_{2})_{2} Di-nitro-toluenes. |
|____________________________________________________________
________| | | | C_{6}H_{4}Cl(NO_{2}) Nitro-chloro-benzenes. | | | |
C_{6}Br_{4}(NO_{2})_{2} Tetra-bromo-di-nitrobenzene. |
|____________________________________________________________
________|
The nitro compounds are mostly pale yellow liquids, which distil
unchanged, and volatilise with water vapour, or colourless or pale yellow
needles or prisms. Some of them, however, are of an intense yellow colour.
Many of them explode upon being heated. They are heavier than water, and
insoluble in it, but mostly soluble in alcohol, ether, and glacial acetic acid.
Nitro-benzene, C_{6}H_{5}(NO_{2}), was discovered in 1834 by
Mitscherlich. It is a yellow liquid, with a melting point of +3° C. It has an
intense odour of bitter almonds. It solidifies in the cold. In di-nitro-benzene,
the two nitro groups may be in the meta, ortho, or para position, the meta
position being the most general (see fig., page 4). By recrystallising from
alcohol, pure meta-di-nitro-benzene may be obtained in long colourless
needles. The ortho compound crystallises in tables, and the para in needles.
They are both colourless. When toluene is nitrated, the para and ortho are
chiefly formed, and a very little of the meta compound.
~Nitro Compounds of Benzene and Toluene.~—The preparation of the
nitro derivatives of the hydrocarbons of the benzene series is very simple. It
is only necessary to bring the hydrocarbon into contact with strong nitric
acid, when the reaction takes place, and one or more of the hydrogen atoms
|____________________________________________________________
________| | | | C_{6}H_{2}(CH_{3}){3}NO{2} Nitro-mesitylene. Solid. |
|____________________________________________________________
________| | | | C_{6}H_{3}(CH_{3})(NO_{2})_{2} Di-nitro-toluenes. |
|____________________________________________________________
________| | | | C_{6}H_{4}Cl(NO_{2}) Nitro-chloro-benzenes. | | | |
C_{6}Br_{4}(NO_{2})_{2} Tetra-bromo-di-nitrobenzene. |
|____________________________________________________________
________|
The nitro compounds are mostly pale yellow liquids, which distil
unchanged, and volatilise with water vapour, or colourless or pale yellow
needles or prisms. Some of them, however, are of an intense yellow colour.
Many of them explode upon being heated. They are heavier than water, and
insoluble in it, but mostly soluble in alcohol, ether, and glacial acetic acid.
Nitro-benzene, C_{6}H_{5}(NO_{2}), was discovered in 1834 by
Mitscherlich. It is a yellow liquid, with a melting point of +3° C. It has an
intense odour of bitter almonds. It solidifies in the cold. In di-nitro-benzene,
the two nitro groups may be in the meta, ortho, or para position, the meta
position being the most general (see fig., page 4). By recrystallising from
alcohol, pure meta-di-nitro-benzene may be obtained in long colourless
needles. The ortho compound crystallises in tables, and the para in needles.
They are both colourless. When toluene is nitrated, the para and ortho are
chiefly formed, and a very little of the meta compound.
~Nitro Compounds of Benzene and Toluene.~—The preparation of the
nitro derivatives of the hydrocarbons of the benzene series is very simple. It
is only necessary to bring the hydrocarbon into contact with strong nitric
acid, when the reaction takes place, and one or more of the hydrogen atoms
Page 146
of the hydrocarbon are replaced by the nitryl group (NO_{2}). Thus by the
action of nitric acid on benzene (or benzol), mono-nitro-benzene is formed:
—
C_{6}H_{6} + HNO_{3} = C_{6}H_{5}.NO_{2} +H_{2}O.
Mono-nitro-benzene.
By the action of another molecule of nitric acid, the di-nitro-benzene is
formed:—
C_{6}H_{5}.NO_{2} + HNO_{3} = C_{6}H_{4}(NO_{2}){2} +
H{2}O.
Di-nitro-benzene.
These nitro bodies are not acids, nor are they ethereal salts of nitrous
acid, as nitro-glycerine is of glycerine. They are regarded as formed from
nitric acid by the replacement of hydroxyl by benzene radicals.
~Mono-nitro Benzene~ is made by treating benzene with concentrated
nitric acid, or a mixture of nitric and sulphuric acids. The latter, as in the
case of the nitration of glycerine, takes no part in the reaction, but only
prevents the dilution of the nitric acid by the water formed in the reaction.
Small quantities may be made thus:—Take 150 c.c. of H_{2}SO_{4} and
75 c.c. HNO_{3}, or 1 part nitric to 2 parts sulphuric acid, and put in a
beaker standing in cold water; then add 15 to 20 c.c. of benzene, drop by
drop, waiting between each addition for the completion of the reaction, and
shake well during the operation. When finished, pour contents of beaker
into about a litre of cold water; the nitro-benzol will sink to the bottom.
Decant the water, and wash the nitro-benzol two or three times in a
separating funnel with water. Finally, dry the product by adding a little
granulated calcium chloride, and allowing to stand for some little time, it
may then be distilled. Nitro-benzene is a heavy oily liquid which boils at
action of nitric acid on benzene (or benzol), mono-nitro-benzene is formed:
—
C_{6}H_{6} + HNO_{3} = C_{6}H_{5}.NO_{2} +H_{2}O.
Mono-nitro-benzene.
By the action of another molecule of nitric acid, the di-nitro-benzene is
formed:—
C_{6}H_{5}.NO_{2} + HNO_{3} = C_{6}H_{4}(NO_{2}){2} +
H{2}O.
Di-nitro-benzene.
These nitro bodies are not acids, nor are they ethereal salts of nitrous
acid, as nitro-glycerine is of glycerine. They are regarded as formed from
nitric acid by the replacement of hydroxyl by benzene radicals.
~Mono-nitro Benzene~ is made by treating benzene with concentrated
nitric acid, or a mixture of nitric and sulphuric acids. The latter, as in the
case of the nitration of glycerine, takes no part in the reaction, but only
prevents the dilution of the nitric acid by the water formed in the reaction.
Small quantities may be made thus:—Take 150 c.c. of H_{2}SO_{4} and
75 c.c. HNO_{3}, or 1 part nitric to 2 parts sulphuric acid, and put in a
beaker standing in cold water; then add 15 to 20 c.c. of benzene, drop by
drop, waiting between each addition for the completion of the reaction, and
shake well during the operation. When finished, pour contents of beaker
into about a litre of cold water; the nitro-benzol will sink to the bottom.
Decant the water, and wash the nitro-benzol two or three times in a
separating funnel with water. Finally, dry the product by adding a little
granulated calcium chloride, and allowing to stand for some little time, it
may then be distilled. Nitro-benzene is a heavy oily liquid which boils at
Page 147
205° C., has a specific gravity of 1.2, and an odour like that of oil of bitter
almonds. In the arts it is chiefly used in the preparation of aniline.
~Di-nitro Benzene~ is a product of the further action of nitric acid on
benzene or nitro-benzene. It crystallises in long fine needles or thin rhombic
plates, and melts at 89.9° C. It can be made thus:—The acid mixture used
consists of equal parts of nitric and sulphuric acids, say 50 c.c. of each, and
without cooling add very slowly 10 c.c. of benzene from a pipette. After the
action is over, boil the mixture for a short time, then pour into about half a
litre of water, filter off the crystals thus produced, press between layers of
filter paper, and crystallise from alcohol. Di-nitro-benzene, or meta-di-nitro-
benzene, as it is sometimes called, enters into the composition of several
explosives, such as tonite No. 3, roburite, securite, bellite.
Nitro-benzene is manufactured upon the large scale as follows:—Along a
bench a row of glass flasks, containing 1 gallon each (1 to 2 lbs. benzene),
are placed, and the acids added in small portions at a time, the workmen
commencing with the first, and adding a small quantity to each in turn, until
the nitration was complete. This process was a dangerous one, and is now
obsolete. The first nitro-benzene made commercially in England, by Messrs
Simpson, Maule, and Nicholson, of Kennington, in 1856, was by this
process. Now, however, vertical iron cylinders, made of cast-iron, are used
for the nitrating operation. They are about 4 feet in diameter and 4 feet
deep, and a series are generally arranged in a row, at a convenient height
from the ground, beneath a line of shafting. Each cylinder is covered with a
cast-iron lid having a raised rim all round. A central orifice gives passage to
a vertical shaft, and two or more other conveniently arranged openings
allow the benzene and the mixed acids to flow in. Each of these openings is
surrounded with a deep rim, so that the whole top of the cylinder can be
flooded with water some inches in depth, without any of it running into the
interior of the nitrator. The lid overhangs the cylinder somewhat, and in the
almonds. In the arts it is chiefly used in the preparation of aniline.
~Di-nitro Benzene~ is a product of the further action of nitric acid on
benzene or nitro-benzene. It crystallises in long fine needles or thin rhombic
plates, and melts at 89.9° C. It can be made thus:—The acid mixture used
consists of equal parts of nitric and sulphuric acids, say 50 c.c. of each, and
without cooling add very slowly 10 c.c. of benzene from a pipette. After the
action is over, boil the mixture for a short time, then pour into about half a
litre of water, filter off the crystals thus produced, press between layers of
filter paper, and crystallise from alcohol. Di-nitro-benzene, or meta-di-nitro-
benzene, as it is sometimes called, enters into the composition of several
explosives, such as tonite No. 3, roburite, securite, bellite.
Nitro-benzene is manufactured upon the large scale as follows:—Along a
bench a row of glass flasks, containing 1 gallon each (1 to 2 lbs. benzene),
are placed, and the acids added in small portions at a time, the workmen
commencing with the first, and adding a small quantity to each in turn, until
the nitration was complete. This process was a dangerous one, and is now
obsolete. The first nitro-benzene made commercially in England, by Messrs
Simpson, Maule, and Nicholson, of Kennington, in 1856, was by this
process. Now, however, vertical iron cylinders, made of cast-iron, are used
for the nitrating operation. They are about 4 feet in diameter and 4 feet
deep, and a series are generally arranged in a row, at a convenient height
from the ground, beneath a line of shafting. Each cylinder is covered with a
cast-iron lid having a raised rim all round. A central orifice gives passage to
a vertical shaft, and two or more other conveniently arranged openings
allow the benzene and the mixed acids to flow in. Each of these openings is
surrounded with a deep rim, so that the whole top of the cylinder can be
flooded with water some inches in depth, without any of it running into the
interior of the nitrator. The lid overhangs the cylinder somewhat, and in the
Page 148
outer rim a number of shot- holes or tubes allow the water to flow down all
over the outside of the cylinder into a shallow cast-iron dish, in which it
stands. By means of a good supply of cold water, the top, sides, and bottom
of the whole apparatus is thus cooled and continually flooded. The agitator
consists of cast-iron arms keyed to a vertical shaft, with fixed arms or dash-
plates secured to the sides of the cylinder. The shaft has a mitre wheel
keyed on the top, which works into a corresponding wheel on the horizontal
shafting running along the top of the converters. This latter is secured to a
clutch; and there is a feather on the shaft, so that any one of the converters
can if necessary be put either in or out of gear. This arrangement is
necessary, as riggers or belts of leather, cotton, or indiarubber will not stand
the atmosphere of the nitro-benzole house. Above and close to each nitrator
stands its acid store tank, of iron or stoneware.
The building in which the nitration is carried out should consist of one
story, have a light roof, walls of hard brick, and a concrete floor of 9 to 12
inches thick, and covered with pitch, to protect its surface from the action of
the acids. The floor should be inclined to a drain, to save any nitro-benzol
spilt. Fire hydrants should be placed at convenient places, and it should be
possible to at once fill the building with steam. A 2-inch pipe, with a cock
outside the building, is advisable. The building should also be as far as
possible isolated.
The acids are mixed beforehand, and allowed to cool before use. The
nitric acid used has a specific gravity of 1.388, and should be as free as
possible from the lower oxides of nitrogen. The sulphuric acid has a
specific gravity of 1.845, and contains from 95 to 96 per cent. of mono-
hydrate. A good mixture is 100 parts of nitric to 140 parts of sulphuric acid,
and 78 parts of benzene; or 128 parts HNO_{3}, 179 of H_{2}SO_{4}, and
100 of benzene (C_{6}H_{6}). The benzene having been introduced into
the cylinder, the water is turned on and the apparatus cooled, the agitators
over the outside of the cylinder into a shallow cast-iron dish, in which it
stands. By means of a good supply of cold water, the top, sides, and bottom
of the whole apparatus is thus cooled and continually flooded. The agitator
consists of cast-iron arms keyed to a vertical shaft, with fixed arms or dash-
plates secured to the sides of the cylinder. The shaft has a mitre wheel
keyed on the top, which works into a corresponding wheel on the horizontal
shafting running along the top of the converters. This latter is secured to a
clutch; and there is a feather on the shaft, so that any one of the converters
can if necessary be put either in or out of gear. This arrangement is
necessary, as riggers or belts of leather, cotton, or indiarubber will not stand
the atmosphere of the nitro-benzole house. Above and close to each nitrator
stands its acid store tank, of iron or stoneware.
The building in which the nitration is carried out should consist of one
story, have a light roof, walls of hard brick, and a concrete floor of 9 to 12
inches thick, and covered with pitch, to protect its surface from the action of
the acids. The floor should be inclined to a drain, to save any nitro-benzol
spilt. Fire hydrants should be placed at convenient places, and it should be
possible to at once fill the building with steam. A 2-inch pipe, with a cock
outside the building, is advisable. The building should also be as far as
possible isolated.
The acids are mixed beforehand, and allowed to cool before use. The
nitric acid used has a specific gravity of 1.388, and should be as free as
possible from the lower oxides of nitrogen. The sulphuric acid has a
specific gravity of 1.845, and contains from 95 to 96 per cent. of mono-
hydrate. A good mixture is 100 parts of nitric to 140 parts of sulphuric acid,
and 78 parts of benzene; or 128 parts HNO_{3}, 179 of H_{2}SO_{4}, and
100 of benzene (C_{6}H_{6}). The benzene having been introduced into
the cylinder, the water is turned on and the apparatus cooled, the agitators
Page 149
are set running, and the acid cock turned on so as to allow it to flow in a
very thin stream into the nitrator.
Should it be necessary to check the machinery even for a moment, the
stream of acid must be stopped and the agitation continued for some time,
as the action proceeds with such vigour that if the benzene being nitrated
comes to rest and acid continues to flow, local heating occurs, and the
mixture may inflame. Accidents from this cause have been not infrequent.
The operation requires between eight to ten hours, agitation and cooling
being kept up all the time. When all the acid is added the water is shut off,
and the temperature allowed to rise a little, to about 100° C. When it ceases
to rise the agitators are thrown out of gear, and the mixture allowed some
hours to cool and settle. The acid is then drawn off, and the nitro-benzene is
well washed with water, and sometimes distilled with wet steam, to recover
a little unconverted benzene and a trace of paraffin (about .5 per cent.
together). At many English works, 100 to 200 gallons, or 800 to 1,760 lbs.,
are nitrated at a time, and toluene is often used instead of benzene,
especially if the nitro-benzene is for use as essence of myrbane. The waste
acids, specific gravity 1.6 to 1.7, contain a little nitro-benzene in solution
and some oxalic acid. They are concentrated in cast-iron pots and used over
again.
~Di-nitro Benzene~ is obtained by treating a charge of the hydrocarbon
benzene with double the quantity of mixed acids in two operations, or rather
in two stages, the second lot of acid being run in directly after the first. The
cooling water is then shut off, and the temperature allowed to rise rapidly,
or nitro-benzene already manufactured is taken and again nitrated with
acids. A large quantity of acid fumes come off, and some of the nitro- and
di-nitro-benzol produced comes off at the high temperature which is
attained, and a good condensing apparatus of stoneware must be used to
prevent loss. The product is separated from the acids, washed with cold
very thin stream into the nitrator.
Should it be necessary to check the machinery even for a moment, the
stream of acid must be stopped and the agitation continued for some time,
as the action proceeds with such vigour that if the benzene being nitrated
comes to rest and acid continues to flow, local heating occurs, and the
mixture may inflame. Accidents from this cause have been not infrequent.
The operation requires between eight to ten hours, agitation and cooling
being kept up all the time. When all the acid is added the water is shut off,
and the temperature allowed to rise a little, to about 100° C. When it ceases
to rise the agitators are thrown out of gear, and the mixture allowed some
hours to cool and settle. The acid is then drawn off, and the nitro-benzene is
well washed with water, and sometimes distilled with wet steam, to recover
a little unconverted benzene and a trace of paraffin (about .5 per cent.
together). At many English works, 100 to 200 gallons, or 800 to 1,760 lbs.,
are nitrated at a time, and toluene is often used instead of benzene,
especially if the nitro-benzene is for use as essence of myrbane. The waste
acids, specific gravity 1.6 to 1.7, contain a little nitro-benzene in solution
and some oxalic acid. They are concentrated in cast-iron pots and used over
again.
~Di-nitro Benzene~ is obtained by treating a charge of the hydrocarbon
benzene with double the quantity of mixed acids in two operations, or rather
in two stages, the second lot of acid being run in directly after the first. The
cooling water is then shut off, and the temperature allowed to rise rapidly,
or nitro-benzene already manufactured is taken and again nitrated with
acids. A large quantity of acid fumes come off, and some of the nitro- and
di-nitro-benzol produced comes off at the high temperature which is
attained, and a good condensing apparatus of stoneware must be used to
prevent loss. The product is separated from the acids, washed with cold
Page 150
water and then with hot. It is slightly soluble in water, so that the washing
waters must be kept and used over again. Finally it is allowed to settle, and
run while still warm into iron trays, in which it solidifies in masses 2 or 4
inches thick. It should not contain any nitro-benzol, nor soil a piece of paper
when laid on it, should be well crystallised, fairly hard, and almost
odourless. The chief product is meta-di-nitro-benzene, melting point 89.8,
but ortho-di-nitro-benzene, melting point 118°, and para-di-nitro, melting
point 172°, are also produced. The melting point of the commercial product
is between 85° to 87° C.
Di-nitro-toluene is made in a similar manner. The tri-nitro-benzene can
only be made by using a very large excess of the mixed acids. Nitro-
benzene, when reduced with iron, zinc, or tin, and hydrochloric acids, forms
aniline.
~Roburite.~—This explosive is the invention of a German chemist, Dr
Carl Roth (English patent 267A, 1887), and is now manufactured in
England, at Gathurst, near Wigan. It consists of two component parts, non-
explosive in themselves (Sprengel's principle), but which, when mixed,
form a powerful explosive. The two substances are ammonium nitrate and
chlorinated di-nitro-benzol. Nitro-naphthalene is also used. Nitrate of soda
and sulphate of ammonium are allowed to be mixed with it. The advantages
claimed for the introduction of chlorine into the nitro compound are that
chlorine exerts a loosening effect upon the NO_{2} groups, and enables the
compound to burn more rapidly than when the nitro groups alone are
present.
The formula of chloro-di-nitro-benzol is C_{6}H_{3}Cl(NO_{2})_{2}.
The theoretical percentage of nitrogen, therefore, is 13.82, and of chlorine
17.53. Dr Roth states that, from experiments he has made, the dynamic
effect is considerably increased by the introduction of chlorine into the nitro
waters must be kept and used over again. Finally it is allowed to settle, and
run while still warm into iron trays, in which it solidifies in masses 2 or 4
inches thick. It should not contain any nitro-benzol, nor soil a piece of paper
when laid on it, should be well crystallised, fairly hard, and almost
odourless. The chief product is meta-di-nitro-benzene, melting point 89.8,
but ortho-di-nitro-benzene, melting point 118°, and para-di-nitro, melting
point 172°, are also produced. The melting point of the commercial product
is between 85° to 87° C.
Di-nitro-toluene is made in a similar manner. The tri-nitro-benzene can
only be made by using a very large excess of the mixed acids. Nitro-
benzene, when reduced with iron, zinc, or tin, and hydrochloric acids, forms
aniline.
~Roburite.~—This explosive is the invention of a German chemist, Dr
Carl Roth (English patent 267A, 1887), and is now manufactured in
England, at Gathurst, near Wigan. It consists of two component parts, non-
explosive in themselves (Sprengel's principle), but which, when mixed,
form a powerful explosive. The two substances are ammonium nitrate and
chlorinated di-nitro-benzol. Nitro-naphthalene is also used. Nitrate of soda
and sulphate of ammonium are allowed to be mixed with it. The advantages
claimed for the introduction of chlorine into the nitro compound are that
chlorine exerts a loosening effect upon the NO_{2} groups, and enables the
compound to burn more rapidly than when the nitro groups alone are
present.
The formula of chloro-di-nitro-benzol is C_{6}H_{3}Cl(NO_{2})_{2}.
The theoretical percentage of nitrogen, therefore, is 13.82, and of chlorine
17.53. Dr Roth states that, from experiments he has made, the dynamic
effect is considerably increased by the introduction of chlorine into the nitro
Page 151
compound. Roburite burns quickly, and is not sensitive to shock; it must be
used dry; it cannot be made to explode by concussion, pressure, friction,
fire, or lightning; it does not freeze; it does not give off deleterious fumes,
and it is to all intents and purposes flameless; and when properly tamped
and fired by electricity, can be safely used in fiery mines, neither fine dust
nor gases being ignited by it. The action is rending and not pulverising.
Compared to gunpowder, it is more powerful in a ratio ranging from 2-1/2
to 4 to 1, according to the substance acted upon. It is largely used in
blasting, pit sinking, quarrying, &c., but especially in coal mining.
According to Dr Roth, the following is the equation of its decomposition:—
C_{6}H_{3}Cl(NO_{2}){2} + 9HN{4}NO_{3} = 6CO_{2} + 20N +
HCl.
In appearance roburite is a brownish yellow powder, with the
characteristic smell of nitro-benzol. Its specific gravity is 1.40. The
Company's statement that the fumes of roburite were harmless having been
questioned by the miners of the Garswood Coal and Iron Works Colliery, a
scientific committee was appointed by the management and the men jointly
for the purpose of settling the question. The members of this committee
were Dr N. Hannah, Dr D.J. Mouncey, and Professor H.B. Dixon, F.R.S., of
Owens College. After a protracted investigation, a long and technical report
was issued, completely vindicating the innocuousness of roburite when
properly used. In the words of The Iron and Coal Trades' Review (May 24,
1889), "The verdict, though not on every point in favour of the use in all
circumstances of roburite in coal mines, is yet of so pronounced a character
in its favour as an explosive that it is impossible to resist the conclusion that
the claims put forward on its behalf rest on solid grounds."
Roburite was also one of the explosives investigated by the committee
appointed in September 1889 by the Durham Coalowners' and Miners'
used dry; it cannot be made to explode by concussion, pressure, friction,
fire, or lightning; it does not freeze; it does not give off deleterious fumes,
and it is to all intents and purposes flameless; and when properly tamped
and fired by electricity, can be safely used in fiery mines, neither fine dust
nor gases being ignited by it. The action is rending and not pulverising.
Compared to gunpowder, it is more powerful in a ratio ranging from 2-1/2
to 4 to 1, according to the substance acted upon. It is largely used in
blasting, pit sinking, quarrying, &c., but especially in coal mining.
According to Dr Roth, the following is the equation of its decomposition:—
C_{6}H_{3}Cl(NO_{2}){2} + 9HN{4}NO_{3} = 6CO_{2} + 20N +
HCl.
In appearance roburite is a brownish yellow powder, with the
characteristic smell of nitro-benzol. Its specific gravity is 1.40. The
Company's statement that the fumes of roburite were harmless having been
questioned by the miners of the Garswood Coal and Iron Works Colliery, a
scientific committee was appointed by the management and the men jointly
for the purpose of settling the question. The members of this committee
were Dr N. Hannah, Dr D.J. Mouncey, and Professor H.B. Dixon, F.R.S., of
Owens College. After a protracted investigation, a long and technical report
was issued, completely vindicating the innocuousness of roburite when
properly used. In the words of The Iron and Coal Trades' Review (May 24,
1889), "The verdict, though not on every point in favour of the use in all
circumstances of roburite in coal mines, is yet of so pronounced a character
in its favour as an explosive that it is impossible to resist the conclusion that
the claims put forward on its behalf rest on solid grounds."
Roburite was also one of the explosives investigated by the committee
appointed in September 1889 by the Durham Coalowners' and Miners'
Page 152
Associations, for the purpose of determining whether the fumes produced
by certain explosives are injurious to health. Both owners and workmen
were represented on the committee, which elected Mr T. Bell, H.M.
Inspector of Mines, as its chairman, with Professor P.P. Bedson and Drs
Drummond and Hume as professional advisers. The problem considered
was whether the fumes produced by the combustion of certain explosives,
one of which was roburite, were injurious to health. The trial comprised the
chemical analysis of the air at the "intake," and of the vitiated air during the
firing of the shots at the "return," and also of the smoky air in the vicinity of
the shot-holes. Five pounds and a half of roburite were used in twenty-three
shots. It had been asserted that the fumes from this explosive contained
carbon-monoxide, CO, but no trace of this gas could be discovered after the
explosion. On another occasion, however, when 4.7 lbs. of roburite were
exploded in twenty-three shots, the air at the "return" showed traces of CO
gas to the extent of .042 to .019 per cent. The medical report which Drs
Hume and Drummond presented to the committee shows that they
investigated every case of suspected illness produced by exposure to fumes,
and they could find no evidence of acute illness being caused. They say,
"No case of acute illness has, throughout the inquiry, been brought to our
knowledge, and we are led to the conclusion that such cases have not
occurred."
~Manufacture.~—As now made, roburite is a mixture of ammonium
nitrate and chlorinated di-nitro-benzol. The nitrate of ammonia is first dried
and ground, and then heated in a closed steam-jacketed vessel to a
temperature of 80° C., and the melted organic compound is added, and the
whole stirred until an intimate mixture is obtained. On cooling, the yellow
powder is ready for use, and is stored in straight canisters or made up into
cartridges. Owing to the deliquescent nature of the nitrate of ammonia, the
finished explosive must be kept out of contact with the air, and for this
reason the cartridges are waterproofed by dipping them in melted wax.
by certain explosives are injurious to health. Both owners and workmen
were represented on the committee, which elected Mr T. Bell, H.M.
Inspector of Mines, as its chairman, with Professor P.P. Bedson and Drs
Drummond and Hume as professional advisers. The problem considered
was whether the fumes produced by the combustion of certain explosives,
one of which was roburite, were injurious to health. The trial comprised the
chemical analysis of the air at the "intake," and of the vitiated air during the
firing of the shots at the "return," and also of the smoky air in the vicinity of
the shot-holes. Five pounds and a half of roburite were used in twenty-three
shots. It had been asserted that the fumes from this explosive contained
carbon-monoxide, CO, but no trace of this gas could be discovered after the
explosion. On another occasion, however, when 4.7 lbs. of roburite were
exploded in twenty-three shots, the air at the "return" showed traces of CO
gas to the extent of .042 to .019 per cent. The medical report which Drs
Hume and Drummond presented to the committee shows that they
investigated every case of suspected illness produced by exposure to fumes,
and they could find no evidence of acute illness being caused. They say,
"No case of acute illness has, throughout the inquiry, been brought to our
knowledge, and we are led to the conclusion that such cases have not
occurred."
~Manufacture.~—As now made, roburite is a mixture of ammonium
nitrate and chlorinated di-nitro-benzol. The nitrate of ammonia is first dried
and ground, and then heated in a closed steam-jacketed vessel to a
temperature of 80° C., and the melted organic compound is added, and the
whole stirred until an intimate mixture is obtained. On cooling, the yellow
powder is ready for use, and is stored in straight canisters or made up into
cartridges. Owing to the deliquescent nature of the nitrate of ammonia, the
finished explosive must be kept out of contact with the air, and for this
reason the cartridges are waterproofed by dipping them in melted wax.
Page 153
Roburite is made in Germany, at Witten, Westphalia; and also at the English
Company's extensive works at Gathurst, near Wigan, which have been at
work now for some eighteen years, having started in 1888. These works are
of considerable extent, covering 30 acres of ground, and are equal to an
output of 10 tons a day. A canal runs through the centre, separating the
chemical from the explosive portions of the works, and the Lancashire and
Yorkshire Railway runs up to the doors. Besides sending large quantities of
roburite itself abroad, the Company also export to the various colonies the
two components, as manufactured in the chemical works, and which
separately are quite non-explosive, and which, having arrived at their
destination, can be easily mixed in the proper proportions.
Among the special advantages claimed for roburite are:—First, that it is
impossible to explode a cartridge by percussion, fire, or electric sparks. If a
cartridge or layer be struck with a heavy hammer, the portion struck is
decomposed, owing to the large amount of heat developed by the blow. The
remaining explosive is not in the least affected, and no detonation whatever
takes place. If roburite be mixed with gunpowder, and the gunpowder fired,
the explosion simply scatters the roburite without affecting it in the least. In
fact, the only way to explode roburite is to detonate it by means of a cap of
fulminate, containing at least 1 gramme of fulminate of mercury. Secondly,
its great safety for use in coal mines. Roburite has the great advantage of
exploding by detonation at a very low temperature, indeed so low that a
very slight amount of tamping is required when fired in the most explosive
mixture of air and coal gas possible, and not at all in a mixture of air and
coal dust—a condition in which the use of gunpowder is highly dangerous.
Mr W.J. Orsman, F.I.C., in a paper read at the University College,
Nottingham, in 1893, gives the temperature of detonation of roburite as
below 2,100° C., and of ammonium nitrate as 1,130° C., whereas that of
blasting gelatine is as much as 3,220° C. With regard to the composition of
Company's extensive works at Gathurst, near Wigan, which have been at
work now for some eighteen years, having started in 1888. These works are
of considerable extent, covering 30 acres of ground, and are equal to an
output of 10 tons a day. A canal runs through the centre, separating the
chemical from the explosive portions of the works, and the Lancashire and
Yorkshire Railway runs up to the doors. Besides sending large quantities of
roburite itself abroad, the Company also export to the various colonies the
two components, as manufactured in the chemical works, and which
separately are quite non-explosive, and which, having arrived at their
destination, can be easily mixed in the proper proportions.
Among the special advantages claimed for roburite are:—First, that it is
impossible to explode a cartridge by percussion, fire, or electric sparks. If a
cartridge or layer be struck with a heavy hammer, the portion struck is
decomposed, owing to the large amount of heat developed by the blow. The
remaining explosive is not in the least affected, and no detonation whatever
takes place. If roburite be mixed with gunpowder, and the gunpowder fired,
the explosion simply scatters the roburite without affecting it in the least. In
fact, the only way to explode roburite is to detonate it by means of a cap of
fulminate, containing at least 1 gramme of fulminate of mercury. Secondly,
its great safety for use in coal mines. Roburite has the great advantage of
exploding by detonation at a very low temperature, indeed so low that a
very slight amount of tamping is required when fired in the most explosive
mixture of air and coal gas possible, and not at all in a mixture of air and
coal dust—a condition in which the use of gunpowder is highly dangerous.
Mr W.J. Orsman, F.I.C., in a paper read at the University College,
Nottingham, in 1893, gives the temperature of detonation of roburite as
below 2,100° C., and of ammonium nitrate as 1,130° C., whereas that of
blasting gelatine is as much as 3,220° C. With regard to the composition of
Page 154
the fumes formed by the explosion of roburite, Mr Orsman says: "With
certain safety explosives—roburite, for instance—an excess of the oxidising
material is added, namely, nitrate of ammonia; but in this case the excess of
oxygen here causes a diminution of temperature, as the nitrate of ammonia
on being decomposed absorbs heat. This excess of oxygen effectually
prevents the formation of carbon monoxide (CO) and the oxides of
nitrogen."
The following table (A), also from Mr Orsman's paper, gives the
composition of five prominent explosives, and shows the composition of
the gases formed on explosion. The gases were collected after detonating 10
grms. of each in a closed strong steel cylinder, having an internal diameter
of 5 inches.
With respect to the influence of ammonium nitrate in lowering the
temperature of explosion of the various substances to which it is added, it
was found by a French Commission that, when dry and finely powdered,
ammonium nitrate succeeds in depreciating the heat of decomposition
without reducing the power of the explosive below a useful limit. The
following table (B) shows the composition of the explosives examined, and
the temperatures which accompanied their explosion.
A
____________________________________________________________
__________
||||
| | | Composition of Gases. |
| |Volume |__________________________|
| Explosive. |of Gas | | | | |
| |formed.|CO_{2}.| CO. |CH_{4}| N. |
| | | | | &H. | |
certain safety explosives—roburite, for instance—an excess of the oxidising
material is added, namely, nitrate of ammonia; but in this case the excess of
oxygen here causes a diminution of temperature, as the nitrate of ammonia
on being decomposed absorbs heat. This excess of oxygen effectually
prevents the formation of carbon monoxide (CO) and the oxides of
nitrogen."
The following table (A), also from Mr Orsman's paper, gives the
composition of five prominent explosives, and shows the composition of
the gases formed on explosion. The gases were collected after detonating 10
grms. of each in a closed strong steel cylinder, having an internal diameter
of 5 inches.
With respect to the influence of ammonium nitrate in lowering the
temperature of explosion of the various substances to which it is added, it
was found by a French Commission that, when dry and finely powdered,
ammonium nitrate succeeds in depreciating the heat of decomposition
without reducing the power of the explosive below a useful limit. The
following table (B) shows the composition of the explosives examined, and
the temperatures which accompanied their explosion.
A
____________________________________________________________
__________
||||
| | | Composition of Gases. |
| |Volume |__________________________|
| Explosive. |of Gas | | | | |
| |formed.|CO_{2}.| CO. |CH_{4}| N. |
| | | | | &H. | |
Page 155
|___________________________________|_______|_______|_____|_____
_|_____|
|||||||
| | | Per | Per | Per | Per |
| | c.c. | cent. |cent.|cent. |cent.|
|Gunpowder— | | | | | |
| Nitre 75 parts | | | | | |
| Sulphur 10 '' | 2,214 | 51.3 | 3.5| 3.5 | 41.7|
| Charcoal 15 '' | | | | | |
|Gelignite— | | | | | |
| Nitro-glycerine 56.5 parts | | | | | |
| Nitro-cotton 3.5 '' | 4,980 | 25 | 7 | … | 67 |
| Wood-meal 8.0 '' | | | | | |
| KNO_{3} 32.0 '' | | | | | |
|Tonite— | | | | | |
| Nitro-Cotton | 3,750 | 30 | 8 | … | 62 |
| Barium nitrate | | | | | |
|Roburite— | | | | | |
| Ammonium nitrate, 86 parts | | | | | |
| Di-nitro-chloro-benzol 14 '' | 4,780 | 32 | … | … | 68 |
|Carbonite | | | | | |
| Nitro-glycerine 25 parts | | | | | |
| Wood-meal 40 '' | 2,100 | 19 | 15 | 26 | … |
| Potas. nitrate 34 '' | | | | | |
|___________________________________|_______|_______|_____|_____
_|_____|
B
_____________________________________________________________
_______ | | | | | | | Original | Percentage | Final | | Explosive. | Temperature
|NH_{4}.NO_{3}| Temperature | | |Co-efficient.| added. |Co-efficient.|
_|_____|
|||||||
| | | Per | Per | Per | Per |
| | c.c. | cent. |cent.|cent. |cent.|
|Gunpowder— | | | | | |
| Nitre 75 parts | | | | | |
| Sulphur 10 '' | 2,214 | 51.3 | 3.5| 3.5 | 41.7|
| Charcoal 15 '' | | | | | |
|Gelignite— | | | | | |
| Nitro-glycerine 56.5 parts | | | | | |
| Nitro-cotton 3.5 '' | 4,980 | 25 | 7 | … | 67 |
| Wood-meal 8.0 '' | | | | | |
| KNO_{3} 32.0 '' | | | | | |
|Tonite— | | | | | |
| Nitro-Cotton | 3,750 | 30 | 8 | … | 62 |
| Barium nitrate | | | | | |
|Roburite— | | | | | |
| Ammonium nitrate, 86 parts | | | | | |
| Di-nitro-chloro-benzol 14 '' | 4,780 | 32 | … | … | 68 |
|Carbonite | | | | | |
| Nitro-glycerine 25 parts | | | | | |
| Wood-meal 40 '' | 2,100 | 19 | 15 | 26 | … |
| Potas. nitrate 34 '' | | | | | |
|___________________________________|_______|_______|_____|_____
_|_____|
B
_____________________________________________________________
_______ | | | | | | | Original | Percentage | Final | | Explosive. | Temperature
|NH_{4}.NO_{3}| Temperature | | |Co-efficient.| added. |Co-efficient.|
Page 156
|__________________________|_____________|_____________|_______
______| | | | | | |Nitro-glycerine | 3,200 | … | … | |Blasting gelatine | | | | | (8
per cent. gun-cotton)| 3,090 | 88 | 1,493 | |Dynamite | | | | | (25 per cent.
silica)| 2,940 | 80 | 1,468 | | | | | | |Gun-cotton, 1 | 2,650 | … | … | | | 2,060 |
90.5 | 1,450 | | | | | | |Ammonium nitrate | 1,130 | … | … |
|__________________________|_____________|_____________|_______
______|
~Bellite~ is the patent of Mr Carl Lamm, Managing Director of the
Rötebro Explosive Company, of Stockholm, and is licensed for manufacture
in England. It consists of a mixture of nitrate of ammonia with di- or tri-
nitro-benzol, it has a specific gravity of 1.2 to 1.4 in its granulated state, and
1 litre weighs 800 to 875 grms. Heated in an open vessel, bellite loses its
consistency at 90° C., but does not commence to separate before a
temperature of 200° C. is reached, when it evaporates without exploding. If
heated suddenly, it burns with a sooty flame, somewhat like tar, but if the
source of heat is removed, it will cease burning, and assume a caramel-like
structure. It absorbs very little moisture from the air after it has been
pressed, and if the operation has been performed while the explosive is hot,
the subsequent increase of weight is only 2 per cent. When subjected to the
most powerful blow with a steel hammer upon an iron plate, it neither
explodes nor ignites. A rifle bullet fired into it at 50 yards' distance will not
explode it. Granulated bellite explodes fully by the aid of fulminating
mercury. Fifteen grms. of bellite fired by means of fulminate, projected a
shot from an ordinary mortar, weighing 90 lbs., a distance of 75 yards, 15
grms. of gunpowder, under the same conditions, throwing it only 12 yards.
A weight of 7-1/2 lbs. falling 145 centimetres failed to explode 1 grm. of
bellite.
Various experiments and trials have been made with this explosive by
Professor P.T. Cleve, M.P.F. Chalon, C.N. Hake, and by a committee of
______| | | | | | |Nitro-glycerine | 3,200 | … | … | |Blasting gelatine | | | | | (8
per cent. gun-cotton)| 3,090 | 88 | 1,493 | |Dynamite | | | | | (25 per cent.
silica)| 2,940 | 80 | 1,468 | | | | | | |Gun-cotton, 1 | 2,650 | … | … | | | 2,060 |
90.5 | 1,450 | | | | | | |Ammonium nitrate | 1,130 | … | … |
|__________________________|_____________|_____________|_______
______|
~Bellite~ is the patent of Mr Carl Lamm, Managing Director of the
Rötebro Explosive Company, of Stockholm, and is licensed for manufacture
in England. It consists of a mixture of nitrate of ammonia with di- or tri-
nitro-benzol, it has a specific gravity of 1.2 to 1.4 in its granulated state, and
1 litre weighs 800 to 875 grms. Heated in an open vessel, bellite loses its
consistency at 90° C., but does not commence to separate before a
temperature of 200° C. is reached, when it evaporates without exploding. If
heated suddenly, it burns with a sooty flame, somewhat like tar, but if the
source of heat is removed, it will cease burning, and assume a caramel-like
structure. It absorbs very little moisture from the air after it has been
pressed, and if the operation has been performed while the explosive is hot,
the subsequent increase of weight is only 2 per cent. When subjected to the
most powerful blow with a steel hammer upon an iron plate, it neither
explodes nor ignites. A rifle bullet fired into it at 50 yards' distance will not
explode it. Granulated bellite explodes fully by the aid of fulminating
mercury. Fifteen grms. of bellite fired by means of fulminate, projected a
shot from an ordinary mortar, weighing 90 lbs., a distance of 75 yards, 15
grms. of gunpowder, under the same conditions, throwing it only 12 yards.
A weight of 7-1/2 lbs. falling 145 centimetres failed to explode 1 grm. of
bellite.
Various experiments and trials have been made with this explosive by
Professor P.T. Cleve, M.P.F. Chalon, C.N. Hake, and by a committee of
Page 157
officers of the Swedish Royal Artillery. It is claimed that it is a very
powerful and extremely safe explosive; that it cannot be made to explode
by friction, shock, or pressure, nor by electricity, fire, lightning, &c., and
that it is specially adapted for use in coal mines, &c.; that it can only be
exploded by means of a fulminate detonator, and is perfectly safe to handle
and manufacture; that it does not freeze, can be used as a filling for shells,
and lastly, can be cheaply manufactured.
~Securite~ consists of 26 parts of meta-di-nitro-benzol and 74 parts of
ammonium nitrate. It is a yellow powder, with an odour of nitro-benzol. It
was licensed in 1886. It sometimes contains tri-nitro-benzol, and tri-nitro-
naphthalene. The equation of its combustion is given as
C_{6}H_{4}(NO_{2}){2} + 10(NH{4}NO_{3}) = 6CO_{2} + 22H_{2}O + 11N_{2}
and, like bellite and roburite, it is claimed to be perfectly safe to use in
the presence of fire damp and coal dust.[A] The variety known as Flameless
Securite consists of a mixture of nitrate and oxalate of ammonia and di-
nitro-benzol.
[Footnote A: See paper by S.B. Coxon, North of Eng. Inst. Mining and
Mech. Eng., 11, 2, 87.]
~Kinetite.~—A few years ago an explosive called "Kinetite"[A] was
introduced, but is not manufactured in England. It was the patent of Messrs
Petry and Fallenstein, and consisted of nitro-benzol, thickened or
gelatinised by the addition of some collodion-cotton, incorporated with
finely ground chlorate of potash and precipitated sulphide of antimony. An
analysis gave the following percentages:—
Nitro-benzol, 19.4 per cent.
Chlorate of potash, 76.9 per cent.
powerful and extremely safe explosive; that it cannot be made to explode
by friction, shock, or pressure, nor by electricity, fire, lightning, &c., and
that it is specially adapted for use in coal mines, &c.; that it can only be
exploded by means of a fulminate detonator, and is perfectly safe to handle
and manufacture; that it does not freeze, can be used as a filling for shells,
and lastly, can be cheaply manufactured.
~Securite~ consists of 26 parts of meta-di-nitro-benzol and 74 parts of
ammonium nitrate. It is a yellow powder, with an odour of nitro-benzol. It
was licensed in 1886. It sometimes contains tri-nitro-benzol, and tri-nitro-
naphthalene. The equation of its combustion is given as
C_{6}H_{4}(NO_{2}){2} + 10(NH{4}NO_{3}) = 6CO_{2} + 22H_{2}O + 11N_{2}
and, like bellite and roburite, it is claimed to be perfectly safe to use in
the presence of fire damp and coal dust.[A] The variety known as Flameless
Securite consists of a mixture of nitrate and oxalate of ammonia and di-
nitro-benzol.
[Footnote A: See paper by S.B. Coxon, North of Eng. Inst. Mining and
Mech. Eng., 11, 2, 87.]
~Kinetite.~—A few years ago an explosive called "Kinetite"[A] was
introduced, but is not manufactured in England. It was the patent of Messrs
Petry and Fallenstein, and consisted of nitro-benzol, thickened or
gelatinised by the addition of some collodion-cotton, incorporated with
finely ground chlorate of potash and precipitated sulphide of antimony. An
analysis gave the following percentages:—
Nitro-benzol, 19.4 per cent.
Chlorate of potash, 76.9 per cent.
Page 158
Sulphide of antimony nitro-cotton, 3.7 per cent.
[Footnote A: V. Watson Smith, Jour. Soc. Chem. Ind., January 1887.]
It requires a very high temperature to ignite it, and cannot, under ordinary
circumstances, when unconfined, be exploded by the application of heat. It
is little affected by immersion in water, unless prolonged, when the chlorate
dissolves out, leaving a practical inexplosive residue.[A] It was found to be
very sensitive to combined friction and percussion, and to be readily ignited
by a glancing blow of wood upon wood. It was also deficient in chemical
stability, and has been known to ignite spontaneously both in the laboratory
and in a magazine. It is an orange- coloured plastic mass, and smells of
nitro-benzol.
[Footnote A: Col. Cundill, R.A., "Dict. of Explosives," says: "If,
however, it be exposed to moist and dry air alternately, the chlorate
crystallises out on the surfaces, and renders the explosive very sensitive."]
~Tonite No. 3~ contains 10 to 14 per cent. of nitro-benzol (see Tonite).
Trench's Flameless Explosive contains 10 per cent. of di-nitro-benzol,
together with 85 per cent. of nitrate of ammonia, and 5 per cent. of a
mixture of alum, and the chlorides of sodium and ammonia.
~Tri-nitro-Toluene.~—Toluene, C_{7}H_{8}, now chiefly obtained from
coal- tar, was formerly obtained by the dry distillation of tolu-balsam. It
may be regarded as methyl-benzene, or benzene in which one hydrogen is
replaced by methyl (CH_{3}), thus (C_{6}H_{5}CH_{3}), or as phenyl-
methane, or methane in which one hydrogen atom is replaced by the radical
phenyl (C_{6}H_{5}), thus (CH_{3}C_{6}H_{5}). Toluene is a colourless
liquid, boiling at 110° C., has a specific gravity of .8824 at 0° C., and an
aromatic odour. Tri-nitro-toluene is formed by the action of nitric acid on
toluene. According to Häussermann, it is more advantageous to start with
[Footnote A: V. Watson Smith, Jour. Soc. Chem. Ind., January 1887.]
It requires a very high temperature to ignite it, and cannot, under ordinary
circumstances, when unconfined, be exploded by the application of heat. It
is little affected by immersion in water, unless prolonged, when the chlorate
dissolves out, leaving a practical inexplosive residue.[A] It was found to be
very sensitive to combined friction and percussion, and to be readily ignited
by a glancing blow of wood upon wood. It was also deficient in chemical
stability, and has been known to ignite spontaneously both in the laboratory
and in a magazine. It is an orange- coloured plastic mass, and smells of
nitro-benzol.
[Footnote A: Col. Cundill, R.A., "Dict. of Explosives," says: "If,
however, it be exposed to moist and dry air alternately, the chlorate
crystallises out on the surfaces, and renders the explosive very sensitive."]
~Tonite No. 3~ contains 10 to 14 per cent. of nitro-benzol (see Tonite).
Trench's Flameless Explosive contains 10 per cent. of di-nitro-benzol,
together with 85 per cent. of nitrate of ammonia, and 5 per cent. of a
mixture of alum, and the chlorides of sodium and ammonia.
~Tri-nitro-Toluene.~—Toluene, C_{7}H_{8}, now chiefly obtained from
coal- tar, was formerly obtained by the dry distillation of tolu-balsam. It
may be regarded as methyl-benzene, or benzene in which one hydrogen is
replaced by methyl (CH_{3}), thus (C_{6}H_{5}CH_{3}), or as phenyl-
methane, or methane in which one hydrogen atom is replaced by the radical
phenyl (C_{6}H_{5}), thus (CH_{3}C_{6}H_{5}). Toluene is a colourless
liquid, boiling at 110° C., has a specific gravity of .8824 at 0° C., and an
aromatic odour. Tri-nitro-toluene is formed by the action of nitric acid on
toluene. According to Häussermann, it is more advantageous to start with
Page 159
the ortho-para-di-nitro-toluene, which is prepared by allowing a mixture of
75 parts of 91 to 92 per cent. nitric acid and 150 parts of 95 to 96 per cent.
sulphuric acid to run in a thin stream into 100 parts of para-nitro-toluene,
while the latter is kept at a temperature between 60° to 65° C., and
continually stirred. When the acid has all been run in, this mixture is heated
for half an hour to 80° C., and allowed to stand till cold. The excess of nitric
acid is then removed. The residue after this treatment is a homogeneous
crystalline mass of ortho-para-di-nitro- toluene, of which the solidifying
point is 69.5° C. To convert this mass into tri-nitro derivative, it is dissolved
by gently heating it with four times its weight of sulphuric acid (95 to 96
per cent.), and it is then mixed with 1-1/2 times its weight of nitric acid (90
to 92 per cent.), the mixture being kept cool. Afterwards it is digested at 90°
to 95° C., with occasional stirring, until the evolution of gas ceases. This
takes place in about four or five hours.
The operation is now stopped, the product allowed to cool, and the
excess of nitric acid separated from it. The residue is then washed with hot
water and very dilute soda solution, and allowed to solidify without
purification. The solidifying point is 70° C., and the mass is then white,
with a radiating crystalline structure. Bright sparkling crystals, melting at
81.5° C. may, however, be obtained by recrystallisation from hot alcohol.
The yield is from 100 parts di-nitro-toluene, 150 parts of the tri-nitro
derivative. Häussermann states also that 1:2:4:6 tri-nitro- toluene can be
obtained from ordinary commercial di-nitro-toluene melting at 60° to 64°
C.; but when this is used, greater precautions must be exercised, for the
reactions are more violent. Moreover, 10 per cent. more nitric acid is
required, and the yield is 10 per cent. less. He also draws attention to the
slight solubility of tri-nitro-toluene in hot water, and to the fact that it is
decomposed by dilute alkalies and alkaline carbonates—facts which must
be borne in mind in washing the substance. This material is neither difficult
nor dangerous to make. It behaves as a very stable substance when exposed
75 parts of 91 to 92 per cent. nitric acid and 150 parts of 95 to 96 per cent.
sulphuric acid to run in a thin stream into 100 parts of para-nitro-toluene,
while the latter is kept at a temperature between 60° to 65° C., and
continually stirred. When the acid has all been run in, this mixture is heated
for half an hour to 80° C., and allowed to stand till cold. The excess of nitric
acid is then removed. The residue after this treatment is a homogeneous
crystalline mass of ortho-para-di-nitro- toluene, of which the solidifying
point is 69.5° C. To convert this mass into tri-nitro derivative, it is dissolved
by gently heating it with four times its weight of sulphuric acid (95 to 96
per cent.), and it is then mixed with 1-1/2 times its weight of nitric acid (90
to 92 per cent.), the mixture being kept cool. Afterwards it is digested at 90°
to 95° C., with occasional stirring, until the evolution of gas ceases. This
takes place in about four or five hours.
The operation is now stopped, the product allowed to cool, and the
excess of nitric acid separated from it. The residue is then washed with hot
water and very dilute soda solution, and allowed to solidify without
purification. The solidifying point is 70° C., and the mass is then white,
with a radiating crystalline structure. Bright sparkling crystals, melting at
81.5° C. may, however, be obtained by recrystallisation from hot alcohol.
The yield is from 100 parts di-nitro-toluene, 150 parts of the tri-nitro
derivative. Häussermann states also that 1:2:4:6 tri-nitro- toluene can be
obtained from ordinary commercial di-nitro-toluene melting at 60° to 64°
C.; but when this is used, greater precautions must be exercised, for the
reactions are more violent. Moreover, 10 per cent. more nitric acid is
required, and the yield is 10 per cent. less. He also draws attention to the
slight solubility of tri-nitro-toluene in hot water, and to the fact that it is
decomposed by dilute alkalies and alkaline carbonates—facts which must
be borne in mind in washing the substance. This material is neither difficult
nor dangerous to make. It behaves as a very stable substance when exposed
Page 160
to the air under varying conditions of temperature (-10° to +50° C.) for
several months. It cannot be exploded by flame, nor by heating it in an open
vessel. It is only slightly decomposed by strong percussion on an anvil. A
fulminate detonator produces the best explosive effect with tri-nitro-
toluene. It can be used in conjunction with ammonium nitrate, but such
admixture weakens the explosive power; but even then it is stated to be
stronger than an equivalent mixture of di-nitro-benzene and ammonium
nitrate. Mowbray patented a mixture of 3 parts nitro-toluol to 7 of nitro-
glycerine, also in the proportions of 1 to 3, which he states to be a very safe
explosive.
~Faversham Powder.~—One of the explosives on the permitted list (coal
mines) is extensively used, and is manufactured by the Cotton Powder Co.
Ltd. at Faversham. It is composed of tri-nitro-toluol 11 parts, ammonium
nitrate 93 parts, and moisture 1 part. This explosive must be used only when
contained in a case of an alloy of lead, tin, zinc, and antimony thoroughly
waterproof; it must be used only with a detonator or electric detonator of
not less strength than that known as No. 6.
~Nitro-Naphthalene.~—Nitro-naphthalene is formed by the action of
nitric acid on naphthalene (C_{10}H_{8}). Its formula is
C_{10}H_{7}NO_{2}, and it forms yellow needles, melting at 61° C.; and
of di-nitro-naphthalene (C_{10}H_{6}(NO_{2})_{2}), melting point 216°
C. There are also tri-nitro and tetra-nitro and [alpha] and [beta] derivatives
of nitro-naphthalene. It is the di-nitro-naphthalene that is chiefly used in
explosives. It is contained in roburite, securite, romit, Volney's powder, &c.
Fehven has patented an explosive consisting of 10 parts of nitro-
naphthalene mixed with the crude ingredients of gunpowder as follows:—
Nitro-naphthalene, 10 parts; saltpetre, 75 parts; charcoal, 12.5 parts; and
sulphur, 12.5 parts. He states that he obtains a mono-nitro-naphthalene,
containing a small proportion of di-nitro-naphthalene, by digesting 1 part of
several months. It cannot be exploded by flame, nor by heating it in an open
vessel. It is only slightly decomposed by strong percussion on an anvil. A
fulminate detonator produces the best explosive effect with tri-nitro-
toluene. It can be used in conjunction with ammonium nitrate, but such
admixture weakens the explosive power; but even then it is stated to be
stronger than an equivalent mixture of di-nitro-benzene and ammonium
nitrate. Mowbray patented a mixture of 3 parts nitro-toluol to 7 of nitro-
glycerine, also in the proportions of 1 to 3, which he states to be a very safe
explosive.
~Faversham Powder.~—One of the explosives on the permitted list (coal
mines) is extensively used, and is manufactured by the Cotton Powder Co.
Ltd. at Faversham. It is composed of tri-nitro-toluol 11 parts, ammonium
nitrate 93 parts, and moisture 1 part. This explosive must be used only when
contained in a case of an alloy of lead, tin, zinc, and antimony thoroughly
waterproof; it must be used only with a detonator or electric detonator of
not less strength than that known as No. 6.
~Nitro-Naphthalene.~—Nitro-naphthalene is formed by the action of
nitric acid on naphthalene (C_{10}H_{8}). Its formula is
C_{10}H_{7}NO_{2}, and it forms yellow needles, melting at 61° C.; and
of di-nitro-naphthalene (C_{10}H_{6}(NO_{2})_{2}), melting point 216°
C. There are also tri-nitro and tetra-nitro and [alpha] and [beta] derivatives
of nitro-naphthalene. It is the di-nitro-naphthalene that is chiefly used in
explosives. It is contained in roburite, securite, romit, Volney's powder, &c.
Fehven has patented an explosive consisting of 10 parts of nitro-
naphthalene mixed with the crude ingredients of gunpowder as follows:—
Nitro-naphthalene, 10 parts; saltpetre, 75 parts; charcoal, 12.5 parts; and
sulphur, 12.5 parts. He states that he obtains a mono-nitro-naphthalene,
containing a small proportion of di-nitro-naphthalene, by digesting 1 part of
Page 161
naphthalene, with or without heat, in 4 parts of nitric acid (specific gravity
1.40) for five days.
Quite lately a patent has been taken out for a mixture of nitro-
naphthalene or di-nitro-benzene with ammonium nitrate, and consists in
using a solvent for one or other or both of the ingredients, effected in a wet
state, and then evaporating off the solvent, care being taken not to melt the
hydrocarbon. In this way a more intimate mixture is ensured between the
particles of the components, and the explosive thus prepared can be fired by
a small detonator, viz., by 0.54 grms. of fulminate. Favier's explosive also
contains mono-nitro-naphthalene (8.5 parts), together with 91.5 parts of
nitrate of ammonia. This explosive is made in England by the Miners'
Safety Explosive Co. A variety of roburite contains chloro-nitro-
naphthalene. Romit consists of 100 parts ammonium nitrate and 7 parts
potassium chlorate mixed with a solution of 1 part nitro- naphthalene and 2
parts rectified paraffin oil.
~Ammonite.~—This explosive was originally made at Vilvorde in
Belgium, under the title of the Favier Explosive, consisting of a compressed
hollow cylinder composed of 91.5 per cent. of nitrate of ammonia, and 8.5
per cent. of mono-nitro-naphthalene filled inside with loose powder of the
same composition. The cartridges were wrapped in paper saturated with
paraffin-wax, and afterwards dipped in hot paraffin to secure their being
water-tight. The Miners' Safety Explosives Co., when making this explosive
at their factory at Stanford-le-Hope, Essex, abandoned after a short trial the
above composition, and substituted di-nitro-naphthalene 11.5 per cent. for
the mono-nitro-naphthalene, and used thin lead envelopes filled with loose
powder slightly pressed in, in place of the compressed cylinders containing
loose powder. The process of manufacture is shortly as follows:—132-3/4
lbs. of thoroughly dried nitrate of ammonium is placed in a mill pan, heated
at the bottom with live steam, and ground for about twenty minutes until it
1.40) for five days.
Quite lately a patent has been taken out for a mixture of nitro-
naphthalene or di-nitro-benzene with ammonium nitrate, and consists in
using a solvent for one or other or both of the ingredients, effected in a wet
state, and then evaporating off the solvent, care being taken not to melt the
hydrocarbon. In this way a more intimate mixture is ensured between the
particles of the components, and the explosive thus prepared can be fired by
a small detonator, viz., by 0.54 grms. of fulminate. Favier's explosive also
contains mono-nitro-naphthalene (8.5 parts), together with 91.5 parts of
nitrate of ammonia. This explosive is made in England by the Miners'
Safety Explosive Co. A variety of roburite contains chloro-nitro-
naphthalene. Romit consists of 100 parts ammonium nitrate and 7 parts
potassium chlorate mixed with a solution of 1 part nitro- naphthalene and 2
parts rectified paraffin oil.
~Ammonite.~—This explosive was originally made at Vilvorde in
Belgium, under the title of the Favier Explosive, consisting of a compressed
hollow cylinder composed of 91.5 per cent. of nitrate of ammonia, and 8.5
per cent. of mono-nitro-naphthalene filled inside with loose powder of the
same composition. The cartridges were wrapped in paper saturated with
paraffin-wax, and afterwards dipped in hot paraffin to secure their being
water-tight. The Miners' Safety Explosives Co., when making this explosive
at their factory at Stanford-le-Hope, Essex, abandoned after a short trial the
above composition, and substituted di-nitro-naphthalene 11.5 per cent. for
the mono-nitro-naphthalene, and used thin lead envelopes filled with loose
powder slightly pressed in, in place of the compressed cylinders containing
loose powder. The process of manufacture is shortly as follows:—132-3/4
lbs. of thoroughly dried nitrate of ammonium is placed in a mill pan, heated
at the bottom with live steam, and ground for about twenty minutes until it
Page 162
becomes so dry that a slight dust follows the rollers; then 17-1/2 lbs. of
thoroughly dry di-nitro-naphthalene is added, and the grinding continued
for about ten minutes. Cold water is then circulated through the bottom of
the pan until the material appears of a lightish colour and falls to powder.
(While the pan is hot the whole mass looks slightly plastic and of a darker
colour than when cold.) A slide in the bottom of the pan is then withdrawn,
the whole mass working out until the pan is empty; it is now removed to the
sifting machine, brushed through a wire sieve of about 12 holes to the inch,
and is then ready for filling into cartridges. The hard core is returned from
the sifting machine and turned into one of the pans a few minutes before the
charge is withdrawn.
The ammonite is filled into the metallic cartridges by means of an
archimedian screw working through a brass tube, pushing off the cartridges
as the explosive is fed into them against a slight back pressure; a cover is
screwed on, and they then go to the dipping room, where they are dipped in
hot wax to seal the ends; they are then packed in boxes of 5 lbs. each and
are ready for delivery. The di-nitro-naphthalene is made at the factory.
Mono-nitro-naphthalene is first made as follows:—12 parts of commercial
nitrate of soda are ground to a fine powder, and further ground with the
addition of 15 parts of refined naphthalene until thoroughly incorporated; it
is then placed in an earthenware pan, and 30 parts of sulphuric acid of 66°
B. added, 2 parts at a time, during forty-eight hours (the rate of adding
H_{2}SO_{4} depends on the condition of the charge, and keeping it in a
fluid state), with frequent agitation, day and night, during the first three or
four days, afterwards three or four times a day. In all fourteen days are
occupied in the nitration process. It is then strained through an earthenware
strainer, washed with warm water, drained, and dried. For the purpose of
producing this material in a granulated condition, which is found more
convenient for drying, and further nitrification, it is placed in a tub, and live
steam passed through, until brought up to the boiling point (the tub should
thoroughly dry di-nitro-naphthalene is added, and the grinding continued
for about ten minutes. Cold water is then circulated through the bottom of
the pan until the material appears of a lightish colour and falls to powder.
(While the pan is hot the whole mass looks slightly plastic and of a darker
colour than when cold.) A slide in the bottom of the pan is then withdrawn,
the whole mass working out until the pan is empty; it is now removed to the
sifting machine, brushed through a wire sieve of about 12 holes to the inch,
and is then ready for filling into cartridges. The hard core is returned from
the sifting machine and turned into one of the pans a few minutes before the
charge is withdrawn.
The ammonite is filled into the metallic cartridges by means of an
archimedian screw working through a brass tube, pushing off the cartridges
as the explosive is fed into them against a slight back pressure; a cover is
screwed on, and they then go to the dipping room, where they are dipped in
hot wax to seal the ends; they are then packed in boxes of 5 lbs. each and
are ready for delivery. The di-nitro-naphthalene is made at the factory.
Mono-nitro-naphthalene is first made as follows:—12 parts of commercial
nitrate of soda are ground to a fine powder, and further ground with the
addition of 15 parts of refined naphthalene until thoroughly incorporated; it
is then placed in an earthenware pan, and 30 parts of sulphuric acid of 66°
B. added, 2 parts at a time, during forty-eight hours (the rate of adding
H_{2}SO_{4} depends on the condition of the charge, and keeping it in a
fluid state), with frequent agitation, day and night, during the first three or
four days, afterwards three or four times a day. In all fourteen days are
occupied in the nitration process. It is then strained through an earthenware
strainer, washed with warm water, drained, and dried. For the purpose of
producing this material in a granulated condition, which is found more
convenient for drying, and further nitrification, it is placed in a tub, and live
steam passed through, until brought up to the boiling point (the tub should
Page 163
be about half full), cold water is then run in whilst violently agitating the
contents until the naphthalene solidifies; it can then be easily drained and
dried. For the further treatment to make di-nitro-naphthalene, 18 parts of
nitro-naphthalene are placed in an earthenware pan, together with 39 parts
of sulphuric acid of 66° B., then 15 parts of nitric acid of 40° B. are added,
in small quantities at a time, stirring the mixture continually. This adding of
nitric acid is controlled by the fuming, which should be kept down as much
as possible. The operation takes ten to twelve days, when 100 times the
above quantities, taken in kilogrammes, are taken. At the end of the
nitration the di-nitro-naphthalene is removed to earthenware strainers,
allowed to drain, washed with hot water and soda until all acid is removed,
washed with water and dried. The di-nitro- naphthalene gives some trouble
in washing, as some acid is held in the crystals which is liable to make its
appearance when crushed. To avoid this it should be ground and washed
with carbonate of soda before drying; an excess of carbonate of soda should
not, however, be used.
~Electronite.~—This is a high explosive designed to afford safety in coal
getting. This important end has been attained by using such ingredients, and
so proportioning them, as will ensure on detonation a degree of heat
insufficient under the conditions of a "blown-out" shot, to ignite fire damp
or coal dust. It is of the nitrate of ammonium class of permitted explosives.
It contains about 75 per cent. of nitrate of ammonium, with the addition of
nitrate of barium, wood meal, and starch. The gases resulting from
detonation are chiefly water in the gaseous form, nitrogen, and a little
carbon dioxide. It is granulated with the object of preventing missfires from
ramming, to which nitrate of ammonium explosives are somewhat
susceptible. This explosive underwent some exhaustive experiments at the
experimental station near Wigan in 1895, when 8 oz. or 12 oz. charges were
fired unstemmed into an admixture of coal dust and 10 per cent. of gas,
contents until the naphthalene solidifies; it can then be easily drained and
dried. For the further treatment to make di-nitro-naphthalene, 18 parts of
nitro-naphthalene are placed in an earthenware pan, together with 39 parts
of sulphuric acid of 66° B., then 15 parts of nitric acid of 40° B. are added,
in small quantities at a time, stirring the mixture continually. This adding of
nitric acid is controlled by the fuming, which should be kept down as much
as possible. The operation takes ten to twelve days, when 100 times the
above quantities, taken in kilogrammes, are taken. At the end of the
nitration the di-nitro-naphthalene is removed to earthenware strainers,
allowed to drain, washed with hot water and soda until all acid is removed,
washed with water and dried. The di-nitro- naphthalene gives some trouble
in washing, as some acid is held in the crystals which is liable to make its
appearance when crushed. To avoid this it should be ground and washed
with carbonate of soda before drying; an excess of carbonate of soda should
not, however, be used.
~Electronite.~—This is a high explosive designed to afford safety in coal
getting. This important end has been attained by using such ingredients, and
so proportioning them, as will ensure on detonation a degree of heat
insufficient under the conditions of a "blown-out" shot, to ignite fire damp
or coal dust. It is of the nitrate of ammonium class of permitted explosives.
It contains about 75 per cent. of nitrate of ammonium, with the addition of
nitrate of barium, wood meal, and starch. The gases resulting from
detonation are chiefly water in the gaseous form, nitrogen, and a little
carbon dioxide. It is granulated with the object of preventing missfires from
ramming, to which nitrate of ammonium explosives are somewhat
susceptible. This explosive underwent some exhaustive experiments at the
experimental station near Wigan in 1895, when 8 oz. or 12 oz. charges were
fired unstemmed into an admixture of coal dust and 10 per cent. of gas,
Page 164
without any ignition taking place. It is manufactured by Messrs Curtis's &
Harvey Ltd. at their factory, Tonbridge, Kent.
~Sprengel's Explosives.~—This is a large class of explosives. The
essential principle of them all is the admixture of an oxidising with a
combustible agent at the time of, or just before, being required for use, the
constituents of the mixture being very often non-explosive bodies. This type
of explosive is due to the late Dr Herman Sprengel, F.R.S. Following up the
idea that an explosion is a sudden combustion, he submitted a variety of
mixtures of oxidising and combustible agents to the violent shock of a
detonator of fulminate. These mixtures were made in such proportions that
the mutual oxidation or de-oxidation should be theoretically complete.
Among them are the following:—
1. One chemical equivalent of nitro-benzene to equivalents of nitric acid.
2. Five equivalents of picric acid to 13 equivalents of nitric acid.
3. Eighty-seven equivalents of nitro-naphthalene to 413 equivalents of
nitric acid.
4. Porous cakes, or lumps of chlorate of potash, exploded violently with
bisulphide of carbon, nitro-benzol, carbonic acid, sulphur, benzene, and
mixtures of these substances.
No. 1 covers the explosive known as Hellhoffite, and No. 2 is really
oxonite, and No. 4 resembles rack-a-rock, an explosive invented by Mr S.R.
Divine, and consisting of a mixture of chlorate of potash and nitro- benzol.
Roburite, bellite, and securite should perhaps be regarded as belonging to
the Sprengel class of explosives, otherwise this class is not manufactured or
used in England. The principal members are known as Hellhoffite,
consisting of a mixture of nitro-petroleum or nitro-tar oils and nitric acid, or
Harvey Ltd. at their factory, Tonbridge, Kent.
~Sprengel's Explosives.~—This is a large class of explosives. The
essential principle of them all is the admixture of an oxidising with a
combustible agent at the time of, or just before, being required for use, the
constituents of the mixture being very often non-explosive bodies. This type
of explosive is due to the late Dr Herman Sprengel, F.R.S. Following up the
idea that an explosion is a sudden combustion, he submitted a variety of
mixtures of oxidising and combustible agents to the violent shock of a
detonator of fulminate. These mixtures were made in such proportions that
the mutual oxidation or de-oxidation should be theoretically complete.
Among them are the following:—
1. One chemical equivalent of nitro-benzene to equivalents of nitric acid.
2. Five equivalents of picric acid to 13 equivalents of nitric acid.
3. Eighty-seven equivalents of nitro-naphthalene to 413 equivalents of
nitric acid.
4. Porous cakes, or lumps of chlorate of potash, exploded violently with
bisulphide of carbon, nitro-benzol, carbonic acid, sulphur, benzene, and
mixtures of these substances.
No. 1 covers the explosive known as Hellhoffite, and No. 2 is really
oxonite, and No. 4 resembles rack-a-rock, an explosive invented by Mr S.R.
Divine, and consisting of a mixture of chlorate of potash and nitro- benzol.
Roburite, bellite, and securite should perhaps be regarded as belonging to
the Sprengel class of explosives, otherwise this class is not manufactured or
used in England. The principal members are known as Hellhoffite,
consisting of a mixture of nitro-petroleum or nitro-tar oils and nitric acid, or
Page 165
of meta-di-nitro-benzol and nitric acid; Oxonite, consisting of picric and
nitric acids; and Panclastite, a name given to various mixtures, proposed by
M. Turpin, such as liquid nitric peroxide, with bisulphide of carbon, benzol,
petroleum, ether, or mineral oils.
~Picric Acid, Tri-nitro-Phenol, or Carbazotic Acid.~—Picric acid, or a
tri-nitro-phenol (C_{6}H_{2}(NO_{2})_{3}OH)[2:4:6], is produced by the
action of nitric acid on many organic substances, such as phenol, indigo,
wool, aniline, resins, &c. At one time a yellow gum from Botany Bay
(Xanthorrhoea hastilis) was chiefly used. One part of phenol (carbolic
acid), C_{6}H_{5}OH, is added to 3 parts of strong fuming nitric acid,
slightly warmed, and when the violence of the reaction has subsided, boiled
till nitrous fumes are no longer evolved. The resinous mass thus produced is
boiled with water, the resulting picric acid is converted into a sodium salt
by a solution of sodium carbonate, which throws down sodium picrate in
crystals.
Phenol-sulphuric acid is now, however, more generally used, and the
apparatus employed for producing it closely resembles that used in making
nitro-benzol. It is also made commercially by melting carbolic acid, and
mixing it with strong sulphuric acid, then diluting the "sulpho- carbolic"[A]
acid with water, and afterwards running it slowly into a stone tank
containing nitric acid. This is allowed to cool, where the crude picric acid
crystallises out, and the acid liquid (which contains practically no picric
acid, but only sulphuric acid, with some nitric acid) being poured down the
drains. The crude picric acid is then dissolved in water by the aid of steam,
and allowed to cool when most of the picric acid recrystallises. The mother
liquor is transferred to a tank and treated with sulphuric acid, when a further
crop of picric acid crystals is obtained. The crystals of picric acid are further
purified by recrystallisation, drained, and dried at 100° F. on glazed
earthenware trays by the aid of steam. It can also be obtained by the action
nitric acids; and Panclastite, a name given to various mixtures, proposed by
M. Turpin, such as liquid nitric peroxide, with bisulphide of carbon, benzol,
petroleum, ether, or mineral oils.
~Picric Acid, Tri-nitro-Phenol, or Carbazotic Acid.~—Picric acid, or a
tri-nitro-phenol (C_{6}H_{2}(NO_{2})_{3}OH)[2:4:6], is produced by the
action of nitric acid on many organic substances, such as phenol, indigo,
wool, aniline, resins, &c. At one time a yellow gum from Botany Bay
(Xanthorrhoea hastilis) was chiefly used. One part of phenol (carbolic
acid), C_{6}H_{5}OH, is added to 3 parts of strong fuming nitric acid,
slightly warmed, and when the violence of the reaction has subsided, boiled
till nitrous fumes are no longer evolved. The resinous mass thus produced is
boiled with water, the resulting picric acid is converted into a sodium salt
by a solution of sodium carbonate, which throws down sodium picrate in
crystals.
Phenol-sulphuric acid is now, however, more generally used, and the
apparatus employed for producing it closely resembles that used in making
nitro-benzol. It is also made commercially by melting carbolic acid, and
mixing it with strong sulphuric acid, then diluting the "sulpho- carbolic"[A]
acid with water, and afterwards running it slowly into a stone tank
containing nitric acid. This is allowed to cool, where the crude picric acid
crystallises out, and the acid liquid (which contains practically no picric
acid, but only sulphuric acid, with some nitric acid) being poured down the
drains. The crude picric acid is then dissolved in water by the aid of steam,
and allowed to cool when most of the picric acid recrystallises. The mother
liquor is transferred to a tank and treated with sulphuric acid, when a further
crop of picric acid crystals is obtained. The crystals of picric acid are further
purified by recrystallisation, drained, and dried at 100° F. on glazed
earthenware trays by the aid of steam. It can also be obtained by the action
Page 166
of nitric acid on ortho-nitro-phenol, para-nitro-phenol, and di-nitro-phenol
(2:4 and 2:6), but not from meta-nitro-phenol, a fact which indicates its
constitution.[B]
[Footnote A: O. and p. phenolsulphonic acids.
C_{3}H_{4}(OH).SO_{3}H + 3HNO_{3} = C_{6}H_{2}(NO_{2})
{3}OH + H{2}SO_{4} + 2H_{2}O. (Picric acid).]
[Footnote B: Carey Lea, Amer. Jour. Sci., (ii.), xxxii. 180.]
Picric acid crystallises in yellow shining prisms or laminæ having an
intensely bitter taste, and is poisonous. It melts at 122.5° C., sublimes when
cautiously heated, dissolves sparingly in cold water, more easily in hot
water, still more in alcohol. It stains the skin an intense yellow colour, and
is used as a dye for wool and silk. It is a strong acid, forming well
crystallised yellow salts, which detonate violently when heated, some of
them also by percussion. The potassium salt, C_{6}H_{2}
(NO_{2})_{3}OK, crystallises in long needles very slightly soluble in
water. The sodium, ammonium, and barium salts are, however, easily
soluble in water. Picric acid, when heated, burns with a luminous and
smoky flame, and may be burnt away in large quantity without explosion;
but the mere contact of certain metallic oxides, with picric acid, in the
presence of heat, develops powerful explosives, which are capable of acting
as detonators to an indefinite amount of the acid, wet or dry, which is within
reach of their detonative influence. The formula of picric acid is
C_{6}H_{2}|(NO_{2})_{3} |OH.
which shows its formation from phenol (C_{6}H_{5}OH.), three
hydrogen atoms being displaced by the NO_{2} group. The equation of its
formation from phenol is as follows:—
(2:4 and 2:6), but not from meta-nitro-phenol, a fact which indicates its
constitution.[B]
[Footnote A: O. and p. phenolsulphonic acids.
C_{3}H_{4}(OH).SO_{3}H + 3HNO_{3} = C_{6}H_{2}(NO_{2})
{3}OH + H{2}SO_{4} + 2H_{2}O. (Picric acid).]
[Footnote B: Carey Lea, Amer. Jour. Sci., (ii.), xxxii. 180.]
Picric acid crystallises in yellow shining prisms or laminæ having an
intensely bitter taste, and is poisonous. It melts at 122.5° C., sublimes when
cautiously heated, dissolves sparingly in cold water, more easily in hot
water, still more in alcohol. It stains the skin an intense yellow colour, and
is used as a dye for wool and silk. It is a strong acid, forming well
crystallised yellow salts, which detonate violently when heated, some of
them also by percussion. The potassium salt, C_{6}H_{2}
(NO_{2})_{3}OK, crystallises in long needles very slightly soluble in
water. The sodium, ammonium, and barium salts are, however, easily
soluble in water. Picric acid, when heated, burns with a luminous and
smoky flame, and may be burnt away in large quantity without explosion;
but the mere contact of certain metallic oxides, with picric acid, in the
presence of heat, develops powerful explosives, which are capable of acting
as detonators to an indefinite amount of the acid, wet or dry, which is within
reach of their detonative influence. The formula of picric acid is
C_{6}H_{2}|(NO_{2})_{3} |OH.
which shows its formation from phenol (C_{6}H_{5}OH.), three
hydrogen atoms being displaced by the NO_{2} group. The equation of its
formation from phenol is as follows:—
Page 167
C_{6}H_{5}.OH + 3HNO_{3} = C_{6}H_{2}(NO_{2}){3}OH + 3H{2}O.
According to Berthelot, its heat of formation from its elements equals
49.1 calories, and its heat of total combustion by free oxygen is equal to
+618.4 cals. It hardly contains more than half the oxygen necessary for its
complete combustion.
2C_{6}H_{2}(NO_{2}){3}OH + O{10} = 12CO_{2} + 3H_{2} + 3N_{2}.
The percentage composition of picric acid is—Nitrogen, 18.34; oxygen,
49.22; hydrogen, 1.00; and carbon, 31.44, equal to 60.26 per cent. of
NO_{2}. The products of decomposition are carbonic acid, carbonic oxide,
carbon, hydrogen, and nitrogen, and the heat liberated, according to
Berthelot, would be 130.6 cals., or 570 cals. per kilogramme. The reduced
volume of the gases would be 190 litres per equivalent, or 829 litres per
kilogramme. To obtain a total combustion of picric acid it is necessary to
mix with it an oxidising agent, such as a nitrate, chlorate, &c. It has been
proposed to mix picric acid (10 parts) with sodium nitrate (10 parts) and
potassium bichromate (8.3 parts). These proportions would furnish a third
of oxygen in excess of the necessary proportion.
Picric acid was not considered to be an explosive, properly so called, for
a long time after its discovery, but the disastrous accident which occurred at
Manchester (vide Gov. Rep. No. LXXXI., by Colonel (now Sir V.D.)
Majendie, C.B.), and some experiments made by Dr Duprè and Colonel
Majendie to ascertain the cause of the accident, conclusively proved that
this view was wrong. The experiments of Berthelot (Bull. de la Soc. Chim.
de Paris, xlix., p. 456) on the explosive decomposition of picric acid are
also deserving of attention in this connection. If a small quantity of picric
acid be heated in a moderate fire, in a crucible, or even in an open test tube,
it will melt (at 120° C. commercial acid), then give off vapours which catch
fire upon contact with air, and burn with a sooty flame, without exploding.
According to Berthelot, its heat of formation from its elements equals
49.1 calories, and its heat of total combustion by free oxygen is equal to
+618.4 cals. It hardly contains more than half the oxygen necessary for its
complete combustion.
2C_{6}H_{2}(NO_{2}){3}OH + O{10} = 12CO_{2} + 3H_{2} + 3N_{2}.
The percentage composition of picric acid is—Nitrogen, 18.34; oxygen,
49.22; hydrogen, 1.00; and carbon, 31.44, equal to 60.26 per cent. of
NO_{2}. The products of decomposition are carbonic acid, carbonic oxide,
carbon, hydrogen, and nitrogen, and the heat liberated, according to
Berthelot, would be 130.6 cals., or 570 cals. per kilogramme. The reduced
volume of the gases would be 190 litres per equivalent, or 829 litres per
kilogramme. To obtain a total combustion of picric acid it is necessary to
mix with it an oxidising agent, such as a nitrate, chlorate, &c. It has been
proposed to mix picric acid (10 parts) with sodium nitrate (10 parts) and
potassium bichromate (8.3 parts). These proportions would furnish a third
of oxygen in excess of the necessary proportion.
Picric acid was not considered to be an explosive, properly so called, for
a long time after its discovery, but the disastrous accident which occurred at
Manchester (vide Gov. Rep. No. LXXXI., by Colonel (now Sir V.D.)
Majendie, C.B.), and some experiments made by Dr Duprè and Colonel
Majendie to ascertain the cause of the accident, conclusively proved that
this view was wrong. The experiments of Berthelot (Bull. de la Soc. Chim.
de Paris, xlix., p. 456) on the explosive decomposition of picric acid are
also deserving of attention in this connection. If a small quantity of picric
acid be heated in a moderate fire, in a crucible, or even in an open test tube,
it will melt (at 120° C. commercial acid), then give off vapours which catch
fire upon contact with air, and burn with a sooty flame, without exploding.
Page 168
If the burning liquid be poured out upon a cold slab, it will soon go out. A
small quantity carefully heated in a tube, closed at one end, can even be
completely volatilised without apparent decomposition. It is thus obvious
that picric acid is much less explosive than the nitric ethers, such as nitro-
glycerol and nitro-cellulose, and very considerably less explosive than the
nitrogen compounds and fulminates.
It would, however, be quite erroneous to assume that picric acid cannot
explode when simply heated. On the contrary, Berthelot has proved that this
is not the case. If a glass tube be heated to redness, and a minute quantity of
picric acid crystals be then thrown in, it will explode with a curious
characteristic noise. If the quantity be increased so that the temperature of
the tube is materially reduced, no explosion will take place at once, but the
substance will volatilise and then explode, though with much less violence
than before, in the upper part of the tube. Finally, if the amount of picric
acid be still further increased under these conditions, it will undergo partial
decomposition and volatilise, but will not even deflagrate. Nitro-benzene,
di-nitrobenzene, and mono-, di-, and tri-nitro-naphthalenes behave
similarly.
The manner in which picric acid will decompose is thus dependent upon
the initial temperature of the decomposition, and if the surrounding material
absorb heat as fast as it is produced by the decomposition, there will be no
explosion and no deflagration. If, however, the absorption is not sufficient
to prevent deflagration, this may so increase the temperature of the
surrounding materials that the deflagration will then end in explosion. Thus,
if an explosion were started in an isolated spot, it would extend throughout
the mass, and give rise to a general explosion.
In the manufacture of picric acid the first obvious and most necessary
precaution is to isolate the substance from other chemicals with which it
small quantity carefully heated in a tube, closed at one end, can even be
completely volatilised without apparent decomposition. It is thus obvious
that picric acid is much less explosive than the nitric ethers, such as nitro-
glycerol and nitro-cellulose, and very considerably less explosive than the
nitrogen compounds and fulminates.
It would, however, be quite erroneous to assume that picric acid cannot
explode when simply heated. On the contrary, Berthelot has proved that this
is not the case. If a glass tube be heated to redness, and a minute quantity of
picric acid crystals be then thrown in, it will explode with a curious
characteristic noise. If the quantity be increased so that the temperature of
the tube is materially reduced, no explosion will take place at once, but the
substance will volatilise and then explode, though with much less violence
than before, in the upper part of the tube. Finally, if the amount of picric
acid be still further increased under these conditions, it will undergo partial
decomposition and volatilise, but will not even deflagrate. Nitro-benzene,
di-nitrobenzene, and mono-, di-, and tri-nitro-naphthalenes behave
similarly.
The manner in which picric acid will decompose is thus dependent upon
the initial temperature of the decomposition, and if the surrounding material
absorb heat as fast as it is produced by the decomposition, there will be no
explosion and no deflagration. If, however, the absorption is not sufficient
to prevent deflagration, this may so increase the temperature of the
surrounding materials that the deflagration will then end in explosion. Thus,
if an explosion were started in an isolated spot, it would extend throughout
the mass, and give rise to a general explosion.
In the manufacture of picric acid the first obvious and most necessary
precaution is to isolate the substance from other chemicals with which it
Page 169
might accidentally come into contact. If pure materials only are used, the
manufacture presents no danger. The finished material, however, must be
carefully kept from contact with nitrates, chlorates, or oxides. If only a little
bit of lime or plaster become accidentally mixed with it, it may become
highly dangerous. A local explosion may occur which might have the effect
of causing the explosion of the whole mass. Picric acid can be fired by a
detonator, 5-grain fulminate, and M. Turpin patented the use of picric acid,
unmixed with any other substance, in 1885. The detonation of a small
quantity of dry picric acid is sufficient to detonate a much larger quantity
containing as much as 17 per cent. of water.
It is chiefly due to French chemists (and to Dr Sprengel) that picric acid
has come to the front as an explosive. Melinite,[A] a substance used by the
French Government for filling shells, was due to M. Turpin, and is
supposed to be little else than fused picric acid mixed with gun-cotton
dissolved in some solvent (acetone or ether-alcohol). Sir F.A. Abel has also
proposed to use picric acid, mixed with nitrate of potash (3 parts) and
picrate of ammonia (2 parts) as a filling for shells. This substance requires a
violent blow and strong confinement to explode it. I am not aware,
however, that it has ever been officially adopted in this country. Messrs
Désignolles and Brugère have introduced military powders, consisting of
mixtures of potassium and ammonium picrates with nitrate of potassium.
M. Désignolles introduced three kinds of picrate powders, composed as
follows:—
___________________________________________________________
________ | | | | | | | For Torpedoes | For Guns. | For Small | | | and Shells. |
Ordinary. Heavy. | Arms. |
|___________________|_______________|___________________|______
_____| | | | | | | | Picrate of Potash | 55-50 | 16.4- 9.6 | 9 | 28.6-22.9 | |
Saltpetre | 45-50 | 74.4-79.7 | 80 | 65.0-69.4 | | Charcoal | … | 9.2-10.7 | 11 |
manufacture presents no danger. The finished material, however, must be
carefully kept from contact with nitrates, chlorates, or oxides. If only a little
bit of lime or plaster become accidentally mixed with it, it may become
highly dangerous. A local explosion may occur which might have the effect
of causing the explosion of the whole mass. Picric acid can be fired by a
detonator, 5-grain fulminate, and M. Turpin patented the use of picric acid,
unmixed with any other substance, in 1885. The detonation of a small
quantity of dry picric acid is sufficient to detonate a much larger quantity
containing as much as 17 per cent. of water.
It is chiefly due to French chemists (and to Dr Sprengel) that picric acid
has come to the front as an explosive. Melinite,[A] a substance used by the
French Government for filling shells, was due to M. Turpin, and is
supposed to be little else than fused picric acid mixed with gun-cotton
dissolved in some solvent (acetone or ether-alcohol). Sir F.A. Abel has also
proposed to use picric acid, mixed with nitrate of potash (3 parts) and
picrate of ammonia (2 parts) as a filling for shells. This substance requires a
violent blow and strong confinement to explode it. I am not aware,
however, that it has ever been officially adopted in this country. Messrs
Désignolles and Brugère have introduced military powders, consisting of
mixtures of potassium and ammonium picrates with nitrate of potassium.
M. Désignolles introduced three kinds of picrate powders, composed as
follows:—
___________________________________________________________
________ | | | | | | | For Torpedoes | For Guns. | For Small | | | and Shells. |
Ordinary. Heavy. | Arms. |
|___________________|_______________|___________________|______
_____| | | | | | | | Picrate of Potash | 55-50 | 16.4- 9.6 | 9 | 28.6-22.9 | |
Saltpetre | 45-50 | 74.4-79.7 | 80 | 65.0-69.4 | | Charcoal | … | 9.2-10.7 | 11 |
Page 170
6.4- 7.7 |
|___________________|_______________|___________|_______|_______
____|
They were made much like ordinary gunpowder, 6 to 14 per cent. of
moisture being added when being milled. The advantages claimed over
gunpowder are greater strength, and consequently greater ballistic or
disruptive effect, comparative absence of smoke, and freedom from
injurious action on the bores of guns, owing to the absence of sulphur.
Brugère's powder is composed of ammonium picrate and nitre, the
proportions being 54 per cent. picrate of ammonia and 46 per cent. potassic
nitrate. It is stable, safe to manufacture and handle, but expensive. It gives
good results in the Chassepôt rifle, very little smoke, and its residue is
small, and consists of carbonate of potash. It is stated that 2.6 grms. used in
a rifle gave an effect equal to 5.5 grms. of ordinary gunpowder.
[Footnote A: The British Lydite and the Japanese Shimose are said to be
identical with Melinite.]
Turpin has patented various mixtures of picric acid, with gum-arabic,
oils, fats, collodion jelly, &c. When the last-named substance is diluted in
the proportion of from 3 to 5 per cent. in a mixture of ether and alcohol, he
states that the blocks of picric acid moulded with it will explode in a closed
chamber with a priming of from 1 to 3 grammes of fulminate. He also casts
picric acid into projectiles, the cast acid having a density of about 1.6. In
this state it resists the shock produced by the firing of a cannon, when
contained in a projectile, having an initial velocity of 600 metres. It is made
in the following way:—The acid is fused in a vessel provided with a false
bottom, heated to 130° to 145° C. by a current of steam under pressure, or
simply by the circulation under the false bottom of a liquid, such as oil,
chloride of zinc, glycerine, &c., heated to the same temperature. The melted
|___________________|_______________|___________|_______|_______
____|
They were made much like ordinary gunpowder, 6 to 14 per cent. of
moisture being added when being milled. The advantages claimed over
gunpowder are greater strength, and consequently greater ballistic or
disruptive effect, comparative absence of smoke, and freedom from
injurious action on the bores of guns, owing to the absence of sulphur.
Brugère's powder is composed of ammonium picrate and nitre, the
proportions being 54 per cent. picrate of ammonia and 46 per cent. potassic
nitrate. It is stable, safe to manufacture and handle, but expensive. It gives
good results in the Chassepôt rifle, very little smoke, and its residue is
small, and consists of carbonate of potash. It is stated that 2.6 grms. used in
a rifle gave an effect equal to 5.5 grms. of ordinary gunpowder.
[Footnote A: The British Lydite and the Japanese Shimose are said to be
identical with Melinite.]
Turpin has patented various mixtures of picric acid, with gum-arabic,
oils, fats, collodion jelly, &c. When the last-named substance is diluted in
the proportion of from 3 to 5 per cent. in a mixture of ether and alcohol, he
states that the blocks of picric acid moulded with it will explode in a closed
chamber with a priming of from 1 to 3 grammes of fulminate. He also casts
picric acid into projectiles, the cast acid having a density of about 1.6. In
this state it resists the shock produced by the firing of a cannon, when
contained in a projectile, having an initial velocity of 600 metres. It is made
in the following way:—The acid is fused in a vessel provided with a false
bottom, heated to 130° to 145° C. by a current of steam under pressure, or
simply by the circulation under the false bottom of a liquid, such as oil,
chloride of zinc, glycerine, &c., heated to the same temperature. The melted
Page 171
picric acid is run into moulds of a form corresponding to that of the blocks
required, or it may be run into projectiles, which should be heated to a
temperature of about 100° C., in order to prevent too rapid solidification.
When cresylic acid (or cresol, C_{6}H_{4}(CH_{3})OH.) is acted upon
by nitric acid it produces a series of nitro compounds very similar to those
formed by nitric acids on phenol, such as sodium di-nitro-cresylate, known
in the arts as victoria yellow. Naphthol, a phenol-like body obtained from
naphthalene, under the same conditions, produces sodium di-nitro-
naphthalic acid, C_{10}H_{6}(NO_{2})_{2}O. The explosive known as
"roburite" contains chloro-nitro-naphthalene, and romit, a Swedish
explosive, nitro-naphthalene.
~Tri-nitro-cresol~, C_{7}H_{4}(NO_{2})_{3}OH.—A body very
similar to tri- nitro-phenol, crystallises in yellow needles, slightly soluble in
cold water, rather more so in boiling water, alcohol, and ether. It melts at
about 100° C. In France it is known as "Cresilite," and mixed with melinite,
is used for charging shells. By neutralising a boiling saturated solution of
tri-nitro-cresol with ammonia, a double salt of ammonium and nitro-cresol
crystallises out upon cooling, which is similar to ammonium picrate. This
salt is known as "Ecrasite," and has been used in Austria for charging shells.
It is a bright yellow solid, greasy to the touch, melts at 100° C., is
unaffected by moisture, heat, or cold, ignites when brought into contact
with an incandescent body or open flame, burning harmlessly away unless
strongly confined, and is insensitive to friction or concussion. It is claimed
to possess double the strength of dynamite, and requires a special detonator
(not less than 2 grms. of fulminate) to provoke its full force.
Notwithstanding the excellent properties attributed to this explosive, Lieut.
W. Walke ("Lectures on Explosives," p. 181) says, "Several imperfectly
explained and unexpected explosions have occurred in loading shells with
required, or it may be run into projectiles, which should be heated to a
temperature of about 100° C., in order to prevent too rapid solidification.
When cresylic acid (or cresol, C_{6}H_{4}(CH_{3})OH.) is acted upon
by nitric acid it produces a series of nitro compounds very similar to those
formed by nitric acids on phenol, such as sodium di-nitro-cresylate, known
in the arts as victoria yellow. Naphthol, a phenol-like body obtained from
naphthalene, under the same conditions, produces sodium di-nitro-
naphthalic acid, C_{10}H_{6}(NO_{2})_{2}O. The explosive known as
"roburite" contains chloro-nitro-naphthalene, and romit, a Swedish
explosive, nitro-naphthalene.
~Tri-nitro-cresol~, C_{7}H_{4}(NO_{2})_{3}OH.—A body very
similar to tri- nitro-phenol, crystallises in yellow needles, slightly soluble in
cold water, rather more so in boiling water, alcohol, and ether. It melts at
about 100° C. In France it is known as "Cresilite," and mixed with melinite,
is used for charging shells. By neutralising a boiling saturated solution of
tri-nitro-cresol with ammonia, a double salt of ammonium and nitro-cresol
crystallises out upon cooling, which is similar to ammonium picrate. This
salt is known as "Ecrasite," and has been used in Austria for charging shells.
It is a bright yellow solid, greasy to the touch, melts at 100° C., is
unaffected by moisture, heat, or cold, ignites when brought into contact
with an incandescent body or open flame, burning harmlessly away unless
strongly confined, and is insensitive to friction or concussion. It is claimed
to possess double the strength of dynamite, and requires a special detonator
(not less than 2 grms. of fulminate) to provoke its full force.
Notwithstanding the excellent properties attributed to this explosive, Lieut.
W. Walke ("Lectures on Explosives," p. 181) says, "Several imperfectly
explained and unexpected explosions have occurred in loading shells with
Page 172
this substance, and have prevented its general adoption up to the present
time."
~The Fulminates.~—The fulminates are salts of fulminic acid,
C_{2}N_{2}O_{2}H_{2}. Their constitution is not very well understood.
Dr
E. Divers, F.R.S., and Mr Kawakita (Chem. Soc. Jour., 1884, pp. 13-19),
give the formulæ of mercury and silver fulminates as
OC = N AgOC = N
/|\|\
Hg | O and | O
\|/|/
-C = N AgC = N
whereas Dr H.E. Armstrong, F.R.S., would prefer to write the formula of
fulminic acid
ON.C.OH. | C(N.OH),
and A.F. Holleman (Berichte, v. xxvi., p. 1403), assigns to mercury
fulminate the formula
C:N.O
Hg | |
C:N.O,
and R. Schol (Ber., v. xxiii., p. 3505),
C:NO
|| Hg.
C:NO
time."
~The Fulminates.~—The fulminates are salts of fulminic acid,
C_{2}N_{2}O_{2}H_{2}. Their constitution is not very well understood.
Dr
E. Divers, F.R.S., and Mr Kawakita (Chem. Soc. Jour., 1884, pp. 13-19),
give the formulæ of mercury and silver fulminates as
OC = N AgOC = N
/|\|\
Hg | O and | O
\|/|/
-C = N AgC = N
whereas Dr H.E. Armstrong, F.R.S., would prefer to write the formula of
fulminic acid
ON.C.OH. | C(N.OH),
and A.F. Holleman (Berichte, v. xxvi., p. 1403), assigns to mercury
fulminate the formula
C:N.O
Hg | |
C:N.O,
and R. Schol (Ber., v. xxiii., p. 3505),
C:NO
|| Hg.
C:NO
Page 173
They are very generally regarded as iso-nitroso compounds.
The principal compound of fulminic acid is the mercury salt commonly
known as fulminating mercury. It is prepared by dissolving mercury in
nitric acid, and then adding alcohol to the solution, 1 part of mercury and 12
parts of nitric acid of specific gravity 1.36, and 5-1/2 parts of 90 per cent.
alcohol being used. As soon as the mixture is in violent reaction, 6 parts
more of alcohol are added slowly to moderate the action. At first the
mixture blackens from the separation of mercury, but this soon vanishes,
and is succeeded by crystalline flocks of mercury fulminate which fall to
the bottom of the vessel. During the reaction, large quantities of volatile
oxidation products of alcohol, such as aldehyde, ethylic nitrate, &c., are
evolved from the boiling liquid, whilst others, such as glycollic acid, remain
in solution. The mercury fulminate is then crystallised from hot water. It
forms white silky, delicate needles, which are with difficulty soluble in cold
water. In the dry state it is extremely explosive, detonating on heating, or by
friction or percussion, as also on contact with concentrated sulphuric acid.
The reaction that takes place upon its decomposition is as follows:—
C_{2}N_{2}O_{2}Hg = Hg + 2CO + N_{2} (284)
According to this equation 1 grm. of the fulminate should yield 235.8 c.c.
(= 66.96 litres for 284 grms.). Berthelot and Vicille have obtained a yield of
234.2 c.c., equal to 66.7 litres for one equivalent 284 grms.
Dry fulminate explodes violently when struck, compressed, or touched
with sulphuric acid, or as an incandescent body. If heated slowly, it
explodes at 152° C., or if heated rapidly, at 187° C. It is often used mixed
with potassium chlorate in detonators. The reaction which takes place in
this case is 3C_{2}N_{2}O_{2}Hg + 2KClO_{3} = 3Hg + 6CO_{2} +
3N_{2} + 2KCl.
The principal compound of fulminic acid is the mercury salt commonly
known as fulminating mercury. It is prepared by dissolving mercury in
nitric acid, and then adding alcohol to the solution, 1 part of mercury and 12
parts of nitric acid of specific gravity 1.36, and 5-1/2 parts of 90 per cent.
alcohol being used. As soon as the mixture is in violent reaction, 6 parts
more of alcohol are added slowly to moderate the action. At first the
mixture blackens from the separation of mercury, but this soon vanishes,
and is succeeded by crystalline flocks of mercury fulminate which fall to
the bottom of the vessel. During the reaction, large quantities of volatile
oxidation products of alcohol, such as aldehyde, ethylic nitrate, &c., are
evolved from the boiling liquid, whilst others, such as glycollic acid, remain
in solution. The mercury fulminate is then crystallised from hot water. It
forms white silky, delicate needles, which are with difficulty soluble in cold
water. In the dry state it is extremely explosive, detonating on heating, or by
friction or percussion, as also on contact with concentrated sulphuric acid.
The reaction that takes place upon its decomposition is as follows:—
C_{2}N_{2}O_{2}Hg = Hg + 2CO + N_{2} (284)
According to this equation 1 grm. of the fulminate should yield 235.8 c.c.
(= 66.96 litres for 284 grms.). Berthelot and Vicille have obtained a yield of
234.2 c.c., equal to 66.7 litres for one equivalent 284 grms.
Dry fulminate explodes violently when struck, compressed, or touched
with sulphuric acid, or as an incandescent body. If heated slowly, it
explodes at 152° C., or if heated rapidly, at 187° C. It is often used mixed
with potassium chlorate in detonators. The reaction which takes place in
this case is 3C_{2}N_{2}O_{2}Hg + 2KClO_{3} = 3Hg + 6CO_{2} +
3N_{2} + 2KCl.
Page 174
On adding copper or zinc to a hot saturated solution of the salt, fulminate
of copper or zinc is formed. The copper salt forms highly explosive green
crystals. There is also a double fulminate of copper of ammonia, and of
copper and potassium. Silver fulminite, C_{2}N_{2}O_{2}Ag_{2}, is
prepared in a similar manner to the mercury salt. It separates in fine white
needles, which dissolve in 36 parts of boiling water, and are with difficulty
soluble in cold water. At above 100° C., or on the weakest blow, it explodes
with fearful violence. Even when covered with water it is more sensitive
than the mercury salt. It forms a very sensitive double salt with ammonia
and several other metals. With hydrogen it forms the acid fulminate of
silver. It is used in crackers and bon-bons, and other toy fireworks, in
minute quantities. Gay Lussac found it to be composed as follows:—
Carbon, 7.92 per cent.; nitrogen, 9.24 per cent.; silver, 72.19 per cent.;
oxygen, 10.65 per cent.; and he assigned to it the formula,
C_{2}N_{2}Ag_{2}O_{2}. Laurent and Gerhardt give it the formula,
C_{2}N(NO_{2})Ag_{2}, and thus suppose it to contain nitryl, NO_{2}.
On adding potassium chloride to a boiling solution of argentic fulminate,
as long as a precipitate of argentic chloride forms, there is obtained on
evaporation brilliant white plates, of a very explosive nature, of potassic
argentic fulminate, C(NO_{2})KAg.CN, from whose aqueous solution
nitric acid precipitates a white powder of hydric argentic fulminate,
C(NO_{2})HAg.CN. All attempts to prepare fulminic acid, or nitro-aceto-
nitrile, C(NO_{2})H_{2}CN, from the fulminates have failed. There is a
fulminate of gold, which is a violently explosive buff precipitate, formed
when ammonia is added to ter-chloride of gold, and fulminate of platinum,
a black precipitate formed by the addition of ammonia to a solution of oxide
platinum, in dilute sulphuric acid.
Fulminating silver is a compound obtained by the action of ammonia on
oxide of silver. It is a very violent explosive. Pure mercury fulminate may
of copper or zinc is formed. The copper salt forms highly explosive green
crystals. There is also a double fulminate of copper of ammonia, and of
copper and potassium. Silver fulminite, C_{2}N_{2}O_{2}Ag_{2}, is
prepared in a similar manner to the mercury salt. It separates in fine white
needles, which dissolve in 36 parts of boiling water, and are with difficulty
soluble in cold water. At above 100° C., or on the weakest blow, it explodes
with fearful violence. Even when covered with water it is more sensitive
than the mercury salt. It forms a very sensitive double salt with ammonia
and several other metals. With hydrogen it forms the acid fulminate of
silver. It is used in crackers and bon-bons, and other toy fireworks, in
minute quantities. Gay Lussac found it to be composed as follows:—
Carbon, 7.92 per cent.; nitrogen, 9.24 per cent.; silver, 72.19 per cent.;
oxygen, 10.65 per cent.; and he assigned to it the formula,
C_{2}N_{2}Ag_{2}O_{2}. Laurent and Gerhardt give it the formula,
C_{2}N(NO_{2})Ag_{2}, and thus suppose it to contain nitryl, NO_{2}.
On adding potassium chloride to a boiling solution of argentic fulminate,
as long as a precipitate of argentic chloride forms, there is obtained on
evaporation brilliant white plates, of a very explosive nature, of potassic
argentic fulminate, C(NO_{2})KAg.CN, from whose aqueous solution
nitric acid precipitates a white powder of hydric argentic fulminate,
C(NO_{2})HAg.CN. All attempts to prepare fulminic acid, or nitro-aceto-
nitrile, C(NO_{2})H_{2}CN, from the fulminates have failed. There is a
fulminate of gold, which is a violently explosive buff precipitate, formed
when ammonia is added to ter-chloride of gold, and fulminate of platinum,
a black precipitate formed by the addition of ammonia to a solution of oxide
platinum, in dilute sulphuric acid.
Fulminating silver is a compound obtained by the action of ammonia on
oxide of silver. It is a very violent explosive. Pure mercury fulminate may
Page 175
be kept an indefinite length of time. Water does not affect it. It explodes at
187° C., and on contact with an ignited body. It is very sensitive to shock
and friction, even that of wood upon wood. It is used for discharging bullets
in saloon rifles. Its inflammation is so sudden that it scatters black powder
on which it is placed without igniting it, but it is sufficient to place it in an
envelope, however weak, for ignition to take place, and the more resisting
the envelope the more violent is the shock, a circumstance that plays an
important part in caps and detonators. The presence of 30 per cent. of water
prevents decomposition, 10 per cent. prevents explosion. This is, however,
only true for small quantities, and does not apply to silver fulminate, which
explodes under water by friction. Moist fulminates slowly decompose on
contact with the oxidisable metals. The (reduced) volume of gases obtained
from 1 kilo. is according to Berthelot, 235.6 litres. The equation of its
decomposition is C_{2}HgN_{2}O_{2} = 2CO + N_{2} + Hg.
Fulminate of mercury is manufactured upon the large scale by two
methods. One of these, commonly known as the German method, is
conducted as follows:—One part of mercury is dissolved in 12 parts of
nitric acid of a specific gravity of 1.375, and to this solution 16.5 parts of
absolute alcohol are added by degrees, and heat is then slowly applied to
the mixture until the dense fumes first formed have disappeared, and when
the action has become more violent some more alcohol is added, equal in
volume to that which has already been added. This is added very gradually.
The product obtained, which is mercury fulminate, is 112 per cent. of the
mercury employed. Another method is to dissolve 10 parts of mercury in
100 parts of nitric acid of a gravity of 1.4, and when the solution has
reached a temperature of 54° C, to pour it slowly through a glass funnel into
83 parts of alcohol. When the effervescence ceases, it is filtered through
paper filters, washed, and dried over hot water, at a temperature not
exceeding 100° C. The fulminate is then carefully packed in paper boxes, or
in corked bottles. The product obtained by this process is 130 per cent. of
187° C., and on contact with an ignited body. It is very sensitive to shock
and friction, even that of wood upon wood. It is used for discharging bullets
in saloon rifles. Its inflammation is so sudden that it scatters black powder
on which it is placed without igniting it, but it is sufficient to place it in an
envelope, however weak, for ignition to take place, and the more resisting
the envelope the more violent is the shock, a circumstance that plays an
important part in caps and detonators. The presence of 30 per cent. of water
prevents decomposition, 10 per cent. prevents explosion. This is, however,
only true for small quantities, and does not apply to silver fulminate, which
explodes under water by friction. Moist fulminates slowly decompose on
contact with the oxidisable metals. The (reduced) volume of gases obtained
from 1 kilo. is according to Berthelot, 235.6 litres. The equation of its
decomposition is C_{2}HgN_{2}O_{2} = 2CO + N_{2} + Hg.
Fulminate of mercury is manufactured upon the large scale by two
methods. One of these, commonly known as the German method, is
conducted as follows:—One part of mercury is dissolved in 12 parts of
nitric acid of a specific gravity of 1.375, and to this solution 16.5 parts of
absolute alcohol are added by degrees, and heat is then slowly applied to
the mixture until the dense fumes first formed have disappeared, and when
the action has become more violent some more alcohol is added, equal in
volume to that which has already been added. This is added very gradually.
The product obtained, which is mercury fulminate, is 112 per cent. of the
mercury employed. Another method is to dissolve 10 parts of mercury in
100 parts of nitric acid of a gravity of 1.4, and when the solution has
reached a temperature of 54° C, to pour it slowly through a glass funnel into
83 parts of alcohol. When the effervescence ceases, it is filtered through
paper filters, washed, and dried over hot water, at a temperature not
exceeding 100° C. The fulminate is then carefully packed in paper boxes, or
in corked bottles. The product obtained by this process is 130 per cent. of
Page 176
the mercury taken. This process is the safest, and at the same time the
cheapest. Fulminate should be kept, if possible, in a damp state.
Commercial fulminate is often adulterated with chlorate of potash.
~Detonators~, or caps, are metallic capsules, usually of copper, and
resemble very long percussion caps. The explosive is pure fulminate of
mercury, or a mixture of that substance with nitrate or chlorate of potash,
gun-powder, or sulphur. The following is a common cap mixture:— 100
parts of fulminate of mercury and 50 parts of potassium nitrate, or 100 parts
of fulminate and 60 parts of meal powder. Silver fulminate is also
sometimes used in caps. There are eight sizes made, which vary in
dimensions and in amount of explosive contained. They are further
distinguished as singles, doubles, trebles, &c., according to their number.
Colonel Cundill, R.A. ("Dict. of Explosives"), gives the following list:—
No. 1 contains 300 grms. of explosive per 1000. " 2 " 400 " " " " " " 3 "
540 " " " " " " 4 " 650 " " " " " " 5 " 800 " " " " " " 6 " 1,000 " " " " " " 7 "
1,500 " " " " " " 8 " 2,000 " " " " "
Trebles are generally used for ordinary dynamite, 5, 6, or 7 for gun-
cotton, blasting gelatine, roburite, &c.
In the British service percussion caps, fuses, &c., are formed of 6 parts
by weight of fulminate of mercury, 6 of chlorate of potash, and 4 of
sulphide of antimony; time fuses of 4 parts of fulminate, 6 of potassium
chlorate, 4 of sulphide of antimony, the mixture being damped with a
varnish consisting of 645 grains of shellac dissolved in a pint of methylated
spirit. Abel's fuse (No. 1) consists of a mixture of sulphide of copper,
phosphide of copper, chlorate of potash, and No. 2 of a mixture of gun-
cotton and gun-powder. They are detonated by means of a platinum wire
heated to redness by means of an electric current. Bain's fuse mixture is a
cheapest. Fulminate should be kept, if possible, in a damp state.
Commercial fulminate is often adulterated with chlorate of potash.
~Detonators~, or caps, are metallic capsules, usually of copper, and
resemble very long percussion caps. The explosive is pure fulminate of
mercury, or a mixture of that substance with nitrate or chlorate of potash,
gun-powder, or sulphur. The following is a common cap mixture:— 100
parts of fulminate of mercury and 50 parts of potassium nitrate, or 100 parts
of fulminate and 60 parts of meal powder. Silver fulminate is also
sometimes used in caps. There are eight sizes made, which vary in
dimensions and in amount of explosive contained. They are further
distinguished as singles, doubles, trebles, &c., according to their number.
Colonel Cundill, R.A. ("Dict. of Explosives"), gives the following list:—
No. 1 contains 300 grms. of explosive per 1000. " 2 " 400 " " " " " " 3 "
540 " " " " " " 4 " 650 " " " " " " 5 " 800 " " " " " " 6 " 1,000 " " " " " " 7 "
1,500 " " " " " " 8 " 2,000 " " " " "
Trebles are generally used for ordinary dynamite, 5, 6, or 7 for gun-
cotton, blasting gelatine, roburite, &c.
In the British service percussion caps, fuses, &c., are formed of 6 parts
by weight of fulminate of mercury, 6 of chlorate of potash, and 4 of
sulphide of antimony; time fuses of 4 parts of fulminate, 6 of potassium
chlorate, 4 of sulphide of antimony, the mixture being damped with a
varnish consisting of 645 grains of shellac dissolved in a pint of methylated
spirit. Abel's fuse (No. 1) consists of a mixture of sulphide of copper,
phosphide of copper, chlorate of potash, and No. 2 of a mixture of gun-
cotton and gun-powder. They are detonated by means of a platinum wire
heated to redness by means of an electric current. Bain's fuse mixture is a
Page 177
mixture of subphosphide of copper, sulphide of antimony, and chlorate of
potash.
In the manufacture of percussion caps and detonators the copper blanks
are cut from copper strips and stamped to the required shape. The blanks are
then placed in a gun-metal plate, with the concave side uppermost—a tool
composed of a plate of gun-metal, in which are inserted a number of copper
points, each of the same length, and so spaced apart as to exactly fit each
point into a cap when inverted over a plate containing the blanks. The
points are dipped into a vessel containing the cap composition, which has
been previously moistened with methylated spirit. It is then removed and
placed over the blanks, and a slight blow serves to deposit a small portion
of the cap mixture into each cap. A similar tool is then dipped into shellac
varnish, removed and placed over the caps, when a drop of varnish from
each of the copper points falls into the caps, which are then allowed to dry.
This is a very safe and efficacious method of working.
At the works of the Cotton-Powder Company Limited, at Faversham, the
fulminate is mixed wet with a very finely ground mixture of gun-cotton and
chlorate of potash, in about the proportions of 6 parts fulminate, 1 part gun-
cotton, and 1 part chlorate. The water in which the fulminate is usually
stored is first drained off, and replaced by displacement by methyl-alcohol.
While the fulminate is moist with alcohol, the gun-cotton and chlorate
mixture is added, and well mixed with it. This mixture is then distributed in
the detonators standing in a frame, and each detonator is put separately into
a machine for the purpose of pressing the paste into the detonator shell.
At the eleventh annual meeting of the representatives of the Bavarian
chemical industries at Regensburg, attention was drawn to the unhealthy
nature of the process of charging percussion caps. Numerous miniature
explosions occur, and the air becomes laden with mercurial vapours, which
potash.
In the manufacture of percussion caps and detonators the copper blanks
are cut from copper strips and stamped to the required shape. The blanks are
then placed in a gun-metal plate, with the concave side uppermost—a tool
composed of a plate of gun-metal, in which are inserted a number of copper
points, each of the same length, and so spaced apart as to exactly fit each
point into a cap when inverted over a plate containing the blanks. The
points are dipped into a vessel containing the cap composition, which has
been previously moistened with methylated spirit. It is then removed and
placed over the blanks, and a slight blow serves to deposit a small portion
of the cap mixture into each cap. A similar tool is then dipped into shellac
varnish, removed and placed over the caps, when a drop of varnish from
each of the copper points falls into the caps, which are then allowed to dry.
This is a very safe and efficacious method of working.
At the works of the Cotton-Powder Company Limited, at Faversham, the
fulminate is mixed wet with a very finely ground mixture of gun-cotton and
chlorate of potash, in about the proportions of 6 parts fulminate, 1 part gun-
cotton, and 1 part chlorate. The water in which the fulminate is usually
stored is first drained off, and replaced by displacement by methyl-alcohol.
While the fulminate is moist with alcohol, the gun-cotton and chlorate
mixture is added, and well mixed with it. This mixture is then distributed in
the detonators standing in a frame, and each detonator is put separately into
a machine for the purpose of pressing the paste into the detonator shell.
At the eleventh annual meeting of the representatives of the Bavarian
chemical industries at Regensburg, attention was drawn to the unhealthy
nature of the process of charging percussion caps. Numerous miniature
explosions occur, and the air becomes laden with mercurial vapours, which
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exercise a deleterious influence upon the health of the operatives. There is
equally just cause for apprehension in respect to the poisonous gases which
are evolved during the solution of mercury in nitric acid, and especially
during the subsequent treatment with alcohol. Many methods have been
proposed for dealing with the waste products arising during the
manufacture and manipulation of fulminate of mercury, but according to
Kæmmerer, only one of comparatively recent introduction appears to be at
all satisfactory. It is based upon the fact that mercuric fulminate, when
heated with a large volume of water under high pressure, splits up into
metallic mercury and non-explosive mercurial compounds of unknown
composition.
In mixing the various ingredients with mercury fulminate to form cap
mixtures, they should not be too dry; in fact, they are generally more or less
wet, and mixed in small quantities at a time, in a special house, the floors of
which are covered with carpet, and the tables with felt. Felt shoes are also
worn by the workpeople employed. All the tools and apparatus used must
be kept very clean; for granulating, hair sieves are used, and the granulated
mixture is afterwards dried on light frames, with canvas trays the bottoms
of which are covered with thin paper, and the frames fitted with indiarubber
cushions, to reduce any jars they may receive. The windows of the building
should be painted white to keep out the rays of the sun.
Mr H. Maxim, of New York, has lately patented a composition for
detonators for use with high explosives, which can also be thrown from
ordnance in considerable quantities with safety. The composition is
prepared as follows:—Nitro-glycerine is thickened with pyroxyline to the
consistency of raw rubber. This is done by employing about 75 to 85 per
cent. of nitro-glycerine, and 15 to 25 per cent. of pyroxyline, according to
the stiffness or elasticity of the compound desired. Some solvent that
dissolves the nitro-cotton is also used. The product thus formed is a kind of
equally just cause for apprehension in respect to the poisonous gases which
are evolved during the solution of mercury in nitric acid, and especially
during the subsequent treatment with alcohol. Many methods have been
proposed for dealing with the waste products arising during the
manufacture and manipulation of fulminate of mercury, but according to
Kæmmerer, only one of comparatively recent introduction appears to be at
all satisfactory. It is based upon the fact that mercuric fulminate, when
heated with a large volume of water under high pressure, splits up into
metallic mercury and non-explosive mercurial compounds of unknown
composition.
In mixing the various ingredients with mercury fulminate to form cap
mixtures, they should not be too dry; in fact, they are generally more or less
wet, and mixed in small quantities at a time, in a special house, the floors of
which are covered with carpet, and the tables with felt. Felt shoes are also
worn by the workpeople employed. All the tools and apparatus used must
be kept very clean; for granulating, hair sieves are used, and the granulated
mixture is afterwards dried on light frames, with canvas trays the bottoms
of which are covered with thin paper, and the frames fitted with indiarubber
cushions, to reduce any jars they may receive. The windows of the building
should be painted white to keep out the rays of the sun.
Mr H. Maxim, of New York, has lately patented a composition for
detonators for use with high explosives, which can also be thrown from
ordnance in considerable quantities with safety. The composition is
prepared as follows:—Nitro-glycerine is thickened with pyroxyline to the
consistency of raw rubber. This is done by employing about 75 to 85 per
cent. of nitro-glycerine, and 15 to 25 per cent. of pyroxyline, according to
the stiffness or elasticity of the compound desired. Some solvent that
dissolves the nitro-cotton is also used. The product thus formed is a kind of
Page 179
blasting gelatine, and should be in a pasty condition, in order that it may be
mixed with fulminate of mercury. The solvent used is acetone, and the
quantity of fulminate is between 75 to 85 per cent. of the entire compound.
If desired, the compound can be made less sensitive to shocks by giving it a
spongy consistency by agitating it with air while it is still in a syrupy
condition. The nitro-glycerine, especially in this latter case, may be omitted.
In some cases, when it is desirable to add a deterring medium, nitro-
benzene or some suitable gum is added.
[Illustration: FIG. 34. METHOD OF PREPARING THE CHARGE.]
The method of preparing a blasting charge is as follows:—A piece of
Bickford fuse of the required length is cut clean and is inserted into a
detonator until it reaches the fulminate. The upper portion of the detonator
is then squeezed round the fuse with a pair of nippers. The object of this is
not only to secure that the full power of the detonator may be developed,
but also to fix the fuse in the cap (Fig. 34). When the detonator, &c., is to be
used under water, or in a damp situation, grease or tallow should be placed
round the junction of the cap with the fuse, in order to make a water-tight
joint. A cartridge is then opened and a hole made in its upper end, and the
detonator pushed in nearly up to the top. Gun-cotton or tonite cartridges
generally have a hole already made in the end of the charge. Small charges
of dry gun-cotton, known as primers, are generally used to explode wet
gun-cotton. The detonators (which are often fired by electrical means) are
placed inside these primers (Fig. 35).
[Illustration: FIG. 35. PRIMER.]
One of the forms of electric exploders used is shown in Fig. 36. This
apparatus is made by Messrs John Davis & Son, and is simply a small hand
dynamo, capable of producing a current of electricity of high tension. This
firm are also makers of various forms of low tension exploders. A charge
mixed with fulminate of mercury. The solvent used is acetone, and the
quantity of fulminate is between 75 to 85 per cent. of the entire compound.
If desired, the compound can be made less sensitive to shocks by giving it a
spongy consistency by agitating it with air while it is still in a syrupy
condition. The nitro-glycerine, especially in this latter case, may be omitted.
In some cases, when it is desirable to add a deterring medium, nitro-
benzene or some suitable gum is added.
[Illustration: FIG. 34. METHOD OF PREPARING THE CHARGE.]
The method of preparing a blasting charge is as follows:—A piece of
Bickford fuse of the required length is cut clean and is inserted into a
detonator until it reaches the fulminate. The upper portion of the detonator
is then squeezed round the fuse with a pair of nippers. The object of this is
not only to secure that the full power of the detonator may be developed,
but also to fix the fuse in the cap (Fig. 34). When the detonator, &c., is to be
used under water, or in a damp situation, grease or tallow should be placed
round the junction of the cap with the fuse, in order to make a water-tight
joint. A cartridge is then opened and a hole made in its upper end, and the
detonator pushed in nearly up to the top. Gun-cotton or tonite cartridges
generally have a hole already made in the end of the charge. Small charges
of dry gun-cotton, known as primers, are generally used to explode wet
gun-cotton. The detonators (which are often fired by electrical means) are
placed inside these primers (Fig. 35).
[Illustration: FIG. 35. PRIMER.]
One of the forms of electric exploders used is shown in Fig. 36. This
apparatus is made by Messrs John Davis & Son, and is simply a small hand
dynamo, capable of producing a current of electricity of high tension. This
firm are also makers of various forms of low tension exploders. A charge
Page 180
having been prepared, as in Fig. 34, insert into the bore-hole one or more
cartridges as judged necessary, and squeeze each one down separately with
a wooden rammer, so as to leave no space round the charge, and above this
insert the cartridge containing the fuse and detonator. Now fill up the rest of
the bore-hole with sand, gravel, water, or other tamping. With gelatine
dynamites a firm tamping may be used, but with ordinary dynamite loose
sand is better. The charge is now ready for firing.
[Illustration: FIG. 36.—ELECTRIC EXPLODER.]
cartridges as judged necessary, and squeeze each one down separately with
a wooden rammer, so as to leave no space round the charge, and above this
insert the cartridge containing the fuse and detonator. Now fill up the rest of
the bore-hole with sand, gravel, water, or other tamping. With gelatine
dynamites a firm tamping may be used, but with ordinary dynamite loose
sand is better. The charge is now ready for firing.
[Illustration: FIG. 36.—ELECTRIC EXPLODER.]
Page 181
CHAPTER VI.
SMOKELESS POWDERS.
Smokeless Powder in General—Cordite—Axite—Ballistite—U.S. Naval
Powder—Schultze's E.G. Powder—Indurite—Vielle Poudre—Rifleite—
Cannonite—Walsrode—Cooppal Powders—Amberite—Troisdorf—
Maximite—
Picric Acid Powders, &c., &c.
The progress made in recent years in the manufacture of smokeless
powders has been very great. With a few exceptions, nearly all these
powders are nitro compounds, and chiefly consist of some form of nitro-
cellulose, either in the form of nitro-cotton or nitro-lignine; or else contain,
in addition to the above, nitro-glycerine, with very often some such
substance as camphor, which is used to reduce the sensitiveness of the
explosive. Other nitro bodies that are used, or have been proposed, are
nitro-starch, nitro-jute, nitrated paper, nitro-benzene, di-nitro-benzene,
mixed with a large number of other chemical substances, such as nitrates,
chlorates, &c. And lastly, there are the picrate powders, consisting of picric
acid, either alone or mixed with other substances.
The various smokeless powders may be roughly divided into military and
sporting powders. But this classification is very rough; because although
SMOKELESS POWDERS.
Smokeless Powder in General—Cordite—Axite—Ballistite—U.S. Naval
Powder—Schultze's E.G. Powder—Indurite—Vielle Poudre—Rifleite—
Cannonite—Walsrode—Cooppal Powders—Amberite—Troisdorf—
Maximite—
Picric Acid Powders, &c., &c.
The progress made in recent years in the manufacture of smokeless
powders has been very great. With a few exceptions, nearly all these
powders are nitro compounds, and chiefly consist of some form of nitro-
cellulose, either in the form of nitro-cotton or nitro-lignine; or else contain,
in addition to the above, nitro-glycerine, with very often some such
substance as camphor, which is used to reduce the sensitiveness of the
explosive. Other nitro bodies that are used, or have been proposed, are
nitro-starch, nitro-jute, nitrated paper, nitro-benzene, di-nitro-benzene,
mixed with a large number of other chemical substances, such as nitrates,
chlorates, &c. And lastly, there are the picrate powders, consisting of picric
acid, either alone or mixed with other substances.
The various smokeless powders may be roughly divided into military and
sporting powders. But this classification is very rough; because although
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some of the better known purely military powders are not suited for use in
sporting guns, nearly all the manufacturers of sporting powders also
manufacture a special variety of their particular explosive, fitted for use in
modern rifles or machine guns, and occasionally, it is claimed, for big guns
also.
Of the purely military powders, the best known are cordite, ballistite, and
the French B.N. powder, the German smokeless (which contains nitro-
glycerine and nitro-cotton); and among the general powders, two varieties
of which are manufactured either for rifles or sporting guns, Schultze's, the
E.C. Powders, Walsrode powder, cannonite, Cooppal powder, amberite,
&c., &c.
~Cordite~, the smokeless powder adopted by the British Government, is
the patent of the late Sir F.A. Abel and Sir James Dewar, and is somewhat
similar to blasting gelatine. It is chiefly manufactured at the Royal
Gunpowder Factory at Waltham Abbey, but also at two or three private
factories, including those of the National Explosives Company Limited, the
New Explosives Company Limited, the Cotton-Powder Company Limited,
Messrs Kynock's, &c. As first manufactured it consisted of gun-cotton 37
per cent., nitro-glycerine 58 per cent., and vaseline 5 per cent., but the
modified cordite now made consists of 65 per cent. gun-cotton, 30 per cent.
of nitro-glycerine, and 5 per cent. of vaseline. The gun-cotton used is
composed chiefly of the hexa-nitrate,[A] which is not soluble in nitro-
glycerine. It is therefore necessary to use some solvent such as acetone, in
order to form the jelly with nitro-glycerine. The process of manufacture of
cordite is very similar, as far as the chemical part of the process is
concerned, to that of blasting gelatine, with the exception that some solvent
for the gun-cotton, other than nitro-glycerine has to be used. Both the nitro-
glycerine and the gun-cotton employed must be as dry as possible, and the
latter should not contain more than .6 per cent. of mineral matter and not
sporting guns, nearly all the manufacturers of sporting powders also
manufacture a special variety of their particular explosive, fitted for use in
modern rifles or machine guns, and occasionally, it is claimed, for big guns
also.
Of the purely military powders, the best known are cordite, ballistite, and
the French B.N. powder, the German smokeless (which contains nitro-
glycerine and nitro-cotton); and among the general powders, two varieties
of which are manufactured either for rifles or sporting guns, Schultze's, the
E.C. Powders, Walsrode powder, cannonite, Cooppal powder, amberite,
&c., &c.
~Cordite~, the smokeless powder adopted by the British Government, is
the patent of the late Sir F.A. Abel and Sir James Dewar, and is somewhat
similar to blasting gelatine. It is chiefly manufactured at the Royal
Gunpowder Factory at Waltham Abbey, but also at two or three private
factories, including those of the National Explosives Company Limited, the
New Explosives Company Limited, the Cotton-Powder Company Limited,
Messrs Kynock's, &c. As first manufactured it consisted of gun-cotton 37
per cent., nitro-glycerine 58 per cent., and vaseline 5 per cent., but the
modified cordite now made consists of 65 per cent. gun-cotton, 30 per cent.
of nitro-glycerine, and 5 per cent. of vaseline. The gun-cotton used is
composed chiefly of the hexa-nitrate,[A] which is not soluble in nitro-
glycerine. It is therefore necessary to use some solvent such as acetone, in
order to form the jelly with nitro-glycerine. The process of manufacture of
cordite is very similar, as far as the chemical part of the process is
concerned, to that of blasting gelatine, with the exception that some solvent
for the gun-cotton, other than nitro-glycerine has to be used. Both the nitro-
glycerine and the gun-cotton employed must be as dry as possible, and the
latter should not contain more than .6 per cent. of mineral matter and not
Page 183
more than 10 per cent. of soluble nitro-cellulose, and a nitrogen content of
not less than 12.5 per cent. The dry gun-cotton (about 1 per cent. of
moisture) is placed in an incorporating tank, which consists of a brass-lined
box, some of the acetone is added, and the machine (Fig. 29), is started;
after some time the rest of the acetone is added (20 per cent. in all) and the
paste kneaded for three and a half hours. At the end of this time the Vaseline
is added, and the kneading continued for a further three and a half hours.
The kneading machine (Fig. 29) consists of a trough, composed of two
halves of a cylinder, in each of which is a shaft which carries a revolving
blade. These blades revolve in opposite directions, and one makes about
half the number of revolutions of the other. As the blades very nearly touch
the bottom of the trough, any material brought into the machine is divided
into two parts, kneaded against the bottom, then pushed along the blade,
turned over, and completely mixed. During kneading the acetone gradually
penetrates the mixture, and dissolves both the nitro-cellulose and nitro-
glycerine, and a uniform dough is obtained which gradually assumes a buff
colour. During kneading the mass becomes heated, and therefore cold water
is passed through the jacket of the machine to prevent heating the mixture
above the normal temperature, and consequent evaporation of the acetone.
The top of the machine is closed in with a glass door, in order to prevent as
far as possible the evaporation of the solvent. When the various ingredients
are formed into a homogeneous mass, the mixture is taken to the press
house, where in the form of a plastic mass it is placed in cylindrical moulds.
The mould is inserted in a specially designed press, and the cordite paste
forced through a die with one or more holes. The paste is pressed out by
hydraulic pressure, and the long cord is wound on a metal drum (Fig. 38),
or cut into lengths; in either case the cordite is now sent to the drying
houses, and dried at a temperature of about 100° F. from three to fourteen
days, the time varying with the size. This operation drives off the acetone,
and any moisture the cordite may still contain, and its diameter decreases
not less than 12.5 per cent. The dry gun-cotton (about 1 per cent. of
moisture) is placed in an incorporating tank, which consists of a brass-lined
box, some of the acetone is added, and the machine (Fig. 29), is started;
after some time the rest of the acetone is added (20 per cent. in all) and the
paste kneaded for three and a half hours. At the end of this time the Vaseline
is added, and the kneading continued for a further three and a half hours.
The kneading machine (Fig. 29) consists of a trough, composed of two
halves of a cylinder, in each of which is a shaft which carries a revolving
blade. These blades revolve in opposite directions, and one makes about
half the number of revolutions of the other. As the blades very nearly touch
the bottom of the trough, any material brought into the machine is divided
into two parts, kneaded against the bottom, then pushed along the blade,
turned over, and completely mixed. During kneading the acetone gradually
penetrates the mixture, and dissolves both the nitro-cellulose and nitro-
glycerine, and a uniform dough is obtained which gradually assumes a buff
colour. During kneading the mass becomes heated, and therefore cold water
is passed through the jacket of the machine to prevent heating the mixture
above the normal temperature, and consequent evaporation of the acetone.
The top of the machine is closed in with a glass door, in order to prevent as
far as possible the evaporation of the solvent. When the various ingredients
are formed into a homogeneous mass, the mixture is taken to the press
house, where in the form of a plastic mass it is placed in cylindrical moulds.
The mould is inserted in a specially designed press, and the cordite paste
forced through a die with one or more holes. The paste is pressed out by
hydraulic pressure, and the long cord is wound on a metal drum (Fig. 38),
or cut into lengths; in either case the cordite is now sent to the drying
houses, and dried at a temperature of about 100° F. from three to fourteen
days, the time varying with the size. This operation drives off the acetone,
and any moisture the cordite may still contain, and its diameter decreases
Page 184
somewhat. In case of the finer cordite, such as the rifle cordite, the next
operation is blending. This process consists in mounting ten of the metal
drums on a reeling machine similar to those used for yarns, and winding the
ten cords on to one drum. This operation is known as "ten-stranding."
Furthermore, six "ten-stranded" reels are afterwards wound upon one, and
the "sixty-stranded" reel is then ready to be sent away, This is done in order
to obtain a uniform blending of the material. With cordite of a larger
diameter, the cord is cut into lengths of 12 inches. Every lot of cordite from
each manufacturer has a consecutive number, numbers representing the size
and one or more initial letters to identify the manufacturer. These
regulations do not apply to the Royal Gunpowder Factory, Waltham Abbey.
The finished cordite resembles a cord of gutta-percha, and its colour varies
from light to dark brown. It should not look black or shrivelled, and should
always possess sufficient elasticity to return to its original form after slight
bending. Cordite is practically smokeless. On explosion a very thin vapour
is produced, which is dissipated rapidly. This smokelessness can be
understood from the fact that the products of combustion are nearly all non-
condensible gases, and contain no solid products of combustion which
would cause smoke. For the same muzzle velocity a smaller charge of
cordite than gunpowder is required owing to the greater amount of gas
produced. Cordite is very slow in burning compared to gunpowder. For
firing blank cartridges cordite chips containing no vaseline is used. The rate
at which cordite explodes depends in a measure upon the diameter of the
cords, and the pressure developed upon its mechanical state. The sizes of
cordite used are given by Colonel Barker, R.A., as follows:—
For the .303 rifle .0375 inch diameter. " 12 Pr. B.L. gun .05 " " " .075 " "
4.7-inch Q.F. gun .100 " " 6-inch Q.F. gun .300 " " heavy guns .40 to .50 "
For rifles the cordite is used in bundles of sixty strands, in field-guns in
lengths of 11 to 12 inches, and the thicker cordite is cut up into 14-inch
operation is blending. This process consists in mounting ten of the metal
drums on a reeling machine similar to those used for yarns, and winding the
ten cords on to one drum. This operation is known as "ten-stranding."
Furthermore, six "ten-stranded" reels are afterwards wound upon one, and
the "sixty-stranded" reel is then ready to be sent away, This is done in order
to obtain a uniform blending of the material. With cordite of a larger
diameter, the cord is cut into lengths of 12 inches. Every lot of cordite from
each manufacturer has a consecutive number, numbers representing the size
and one or more initial letters to identify the manufacturer. These
regulations do not apply to the Royal Gunpowder Factory, Waltham Abbey.
The finished cordite resembles a cord of gutta-percha, and its colour varies
from light to dark brown. It should not look black or shrivelled, and should
always possess sufficient elasticity to return to its original form after slight
bending. Cordite is practically smokeless. On explosion a very thin vapour
is produced, which is dissipated rapidly. This smokelessness can be
understood from the fact that the products of combustion are nearly all non-
condensible gases, and contain no solid products of combustion which
would cause smoke. For the same muzzle velocity a smaller charge of
cordite than gunpowder is required owing to the greater amount of gas
produced. Cordite is very slow in burning compared to gunpowder. For
firing blank cartridges cordite chips containing no vaseline is used. The rate
at which cordite explodes depends in a measure upon the diameter of the
cords, and the pressure developed upon its mechanical state. The sizes of
cordite used are given by Colonel Barker, R.A., as follows:—
For the .303 rifle .0375 inch diameter. " 12 Pr. B.L. gun .05 " " " .075 " "
4.7-inch Q.F. gun .100 " " 6-inch Q.F. gun .300 " " heavy guns .40 to .50 "
For rifles the cordite is used in bundles of sixty strands, in field-guns in
lengths of 11 to 12 inches, and the thicker cordite is cut up into 14-inch
Page 185
lengths. Colonel Barker says that the effect of heat upon cordite is not
greater as regards its shooting qualities than upon black powder, and in
speaking of the effect that cordite has upon the guns in which it is used
(R.A. Inst.) said that they had at Waltham Abbey a 4.7-inch Q.F. gun that
had fired 40 rounds of black powder, and 249 rounds of cordite (58 per
cent. nitro-glycerine) and was still in excellent condition, and showed very
little sign of action, and also a 12-lb. B.L. gun that had been much used and
was in no wise injured.
[Footnote A: The gun-cotton used contains 12 per cent. of soluble gun-
cotton, and a nitrogen content of not less than 12.8 to 13.1 per cent.]
[Illustration: Fig. 37 Scale, 1 inch = 1 foot. Single Strand Reel.]
[Illustration: FIG. 38.—"TEN-STRANDING."]
In some experiments made by Captain Sir A. Noble,[A] with the old
cordite containing 58 per cent. nitro-glycerine, a charge of 5 lbs. 10 oz. of
cordite of 0.2 inch diameter was fired. The mean chamber crusher gauge
pressure was 13.3 tons per square inch (maximum 13.6, minimum 12.9), or
a mean of 2,027 atmospheres (max. 2,070, min. 1,970). The muzzle velocity
was 2,146 foot seconds, and the muzzle energy 1,437 foot tons. A gramme
of cordite generated 700 c.c. of permanent gases at 0° C. and 760 mm.
pressure. The quantity of heat developed was 1,260 gramme units. In the
case of cordite, as also with ballistite, a considerable quantity of aqueous
vapour has to be added to the permanent gases formed. A similar trial, in
which 12 lbs. of ordinary pebble powder was used, gave a pressure of 15.9
tons per square inch, or a mean of 2,424 atmospheres. It gave a 45-lb.
projectile a mean muzzle velocity of 1,839 foot seconds, thus developing a
muzzle energy of 1,055 foot tons. A gramme of this powder at 0° C. and
760 mm. generates 280 c.c. of permanent gases, and develops 720 grm.
units of heat.
greater as regards its shooting qualities than upon black powder, and in
speaking of the effect that cordite has upon the guns in which it is used
(R.A. Inst.) said that they had at Waltham Abbey a 4.7-inch Q.F. gun that
had fired 40 rounds of black powder, and 249 rounds of cordite (58 per
cent. nitro-glycerine) and was still in excellent condition, and showed very
little sign of action, and also a 12-lb. B.L. gun that had been much used and
was in no wise injured.
[Footnote A: The gun-cotton used contains 12 per cent. of soluble gun-
cotton, and a nitrogen content of not less than 12.8 to 13.1 per cent.]
[Illustration: Fig. 37 Scale, 1 inch = 1 foot. Single Strand Reel.]
[Illustration: FIG. 38.—"TEN-STRANDING."]
In some experiments made by Captain Sir A. Noble,[A] with the old
cordite containing 58 per cent. nitro-glycerine, a charge of 5 lbs. 10 oz. of
cordite of 0.2 inch diameter was fired. The mean chamber crusher gauge
pressure was 13.3 tons per square inch (maximum 13.6, minimum 12.9), or
a mean of 2,027 atmospheres (max. 2,070, min. 1,970). The muzzle velocity
was 2,146 foot seconds, and the muzzle energy 1,437 foot tons. A gramme
of cordite generated 700 c.c. of permanent gases at 0° C. and 760 mm.
pressure. The quantity of heat developed was 1,260 gramme units. In the
case of cordite, as also with ballistite, a considerable quantity of aqueous
vapour has to be added to the permanent gases formed. A similar trial, in
which 12 lbs. of ordinary pebble powder was used, gave a pressure of 15.9
tons per square inch, or a mean of 2,424 atmospheres. It gave a 45-lb.
projectile a mean muzzle velocity of 1,839 foot seconds, thus developing a
muzzle energy of 1,055 foot tons. A gramme of this powder at 0° C. and
760 mm. generates 280 c.c. of permanent gases, and develops 720 grm.
units of heat.
Page 186
[Footnote A: Proc. Roy. Soc., vol. lii., No. 315.]
In a series of experiments conducted by the War Office Chemical
Committee on Explosives in 1891, it was conclusively shown that
considerable quantities of cordite may be burnt away without explosion. A
number of wooden cases, containing 500 to 600 lbs. each of cordite, were
placed upon a large bonfire of wood, and burned for over a quarter of an
hour without explosion. At Woolwich in 1892 a brown paper packet
containing ten cordite cartridges was fired into with a rifle (.303) loaded
with cordite, without the explosion of a single one of them, which shows its
insensibility to shock.
With respect to the action of cordite upon guns, Sir A. Noble points out
that the erosion caused is of a totally different kind to that of black powder.
The surface of the barrel in the case of cordite appears to be washed away
smoothly by the gases, and not pitted and eaten into as with black powder.
The erosion also extends over a shorter length of surface, and in small arms
it is said to be no greater than in the case of black powder. Sir A. Noble says
in this connection: "It is almost unnecessary to explain that freedom from
rapid erosion is of very high importance in view of the rapid deterioration
of the bores of large guns when fired with charges developing very high
energies. As might perhaps be anticipated from the higher heat of ballistite,
its erosive power is slightly greater than that of cordite, while the erosive
power of cordite is again slightly greater than that of brown prismatic.
Amide powder, on the other hand, possesses the peculiarity of eroding very
much less than any other powder with which I have experimented, its
erosive power being only one-fourth of that of the other powders
enumerated."
TABLE GIVING SOME OF SIR. A. NOBLE'S EXPERIMENTS.
_____________________________________________________________
In a series of experiments conducted by the War Office Chemical
Committee on Explosives in 1891, it was conclusively shown that
considerable quantities of cordite may be burnt away without explosion. A
number of wooden cases, containing 500 to 600 lbs. each of cordite, were
placed upon a large bonfire of wood, and burned for over a quarter of an
hour without explosion. At Woolwich in 1892 a brown paper packet
containing ten cordite cartridges was fired into with a rifle (.303) loaded
with cordite, without the explosion of a single one of them, which shows its
insensibility to shock.
With respect to the action of cordite upon guns, Sir A. Noble points out
that the erosion caused is of a totally different kind to that of black powder.
The surface of the barrel in the case of cordite appears to be washed away
smoothly by the gases, and not pitted and eaten into as with black powder.
The erosion also extends over a shorter length of surface, and in small arms
it is said to be no greater than in the case of black powder. Sir A. Noble says
in this connection: "It is almost unnecessary to explain that freedom from
rapid erosion is of very high importance in view of the rapid deterioration
of the bores of large guns when fired with charges developing very high
energies. As might perhaps be anticipated from the higher heat of ballistite,
its erosive power is slightly greater than that of cordite, while the erosive
power of cordite is again slightly greater than that of brown prismatic.
Amide powder, on the other hand, possesses the peculiarity of eroding very
much less than any other powder with which I have experimented, its
erosive power being only one-fourth of that of the other powders
enumerated."
TABLE GIVING SOME OF SIR. A. NOBLE'S EXPERIMENTS.
_____________________________________________________________
Page 187
___________ | | | VELOCITIES OBTAINED. |
|____________________________________________________________
____________| | | | | | | | | In a 40 | In a 50 | In a 75 | In a 100 | | | Cal. Gun.|
Cal. Gun.| Cal. Gun.| Cal. Gun.|
|____________________________|__________|__________|__________|_
_________| | | | | | | | |Foot Secs.|Foot Secs.|Foot Sees.|Foot Secs.| | | | | | |
|With cordite 0.4 in. diam. | 2,794 | 2,940 | 3,166 | 3,286 | | " " 0.3 " | 2,469 |
2,619 | 2,811 | 2,905 | | " ballistite 0.3 in. cubes| 2,416 | 2,537 | 2,713 | 2,806
| | " French B.N. for | | | | | | 6-inch guns | 2,249 | 2,360 | 2,536 | 2,616 | | "
prismatic amide | 2,218 | 2,342 | 2,511 | 2,574 | | | | | | |
|____________________________|__________|__________|__________|_
_________| | | | ENERGIES REPRESENTED BY ABOVE VELOCITIES. |
|____________________________________________________________
____________| | | | | | | | |Foot Tons.|Foot Tons.|Foot Tons.|Foot Tons.| | | | | | |
| Cordite 0.4 inch | 5,413 | 5,994 | 6,950 | 7,478 | | Ballistite 0.3 inch cubes |
4,227 | 4,754 | 5,479 | 5,852 | | French B.N. | 4,047 | 4,463 | 5,104 | 5,460 | |
Prismatic amide | 3,507 | 3,862 | 4.460 | 4,745 |
|____________________________|__________|__________|__________|_
_________|
And again, in speaking of his own experiments, he says: "One 4.7-inch
gun has fired 1,219 rounds, and another 953, all with full charges of cordite,
while a 6-inch gun has fired 588 rounds with full charges, of which 355
were cordite. In the whole of these guns, so far as I can judge, the erosion is
certainly not greater than with ordinary powder, and differs from it
remarkably in appearance. With ordinary powder a gun, when much eroded,
is deeply furrowed (these furrows having a great tendency to develop into
cracks), and presents much the appearance in miniature of a very roughly
ploughed field. With cordite, on the contrary, the surface appears to be
pretty smoothly swept away, while the length of the surface eroded is
considerably less."
|____________________________________________________________
____________| | | | | | | | | In a 40 | In a 50 | In a 75 | In a 100 | | | Cal. Gun.|
Cal. Gun.| Cal. Gun.| Cal. Gun.|
|____________________________|__________|__________|__________|_
_________| | | | | | | | |Foot Secs.|Foot Secs.|Foot Sees.|Foot Secs.| | | | | | |
|With cordite 0.4 in. diam. | 2,794 | 2,940 | 3,166 | 3,286 | | " " 0.3 " | 2,469 |
2,619 | 2,811 | 2,905 | | " ballistite 0.3 in. cubes| 2,416 | 2,537 | 2,713 | 2,806
| | " French B.N. for | | | | | | 6-inch guns | 2,249 | 2,360 | 2,536 | 2,616 | | "
prismatic amide | 2,218 | 2,342 | 2,511 | 2,574 | | | | | | |
|____________________________|__________|__________|__________|_
_________| | | | ENERGIES REPRESENTED BY ABOVE VELOCITIES. |
|____________________________________________________________
____________| | | | | | | | |Foot Tons.|Foot Tons.|Foot Tons.|Foot Tons.| | | | | | |
| Cordite 0.4 inch | 5,413 | 5,994 | 6,950 | 7,478 | | Ballistite 0.3 inch cubes |
4,227 | 4,754 | 5,479 | 5,852 | | French B.N. | 4,047 | 4,463 | 5,104 | 5,460 | |
Prismatic amide | 3,507 | 3,862 | 4.460 | 4,745 |
|____________________________|__________|__________|__________|_
_________|
And again, in speaking of his own experiments, he says: "One 4.7-inch
gun has fired 1,219 rounds, and another 953, all with full charges of cordite,
while a 6-inch gun has fired 588 rounds with full charges, of which 355
were cordite. In the whole of these guns, so far as I can judge, the erosion is
certainly not greater than with ordinary powder, and differs from it
remarkably in appearance. With ordinary powder a gun, when much eroded,
is deeply furrowed (these furrows having a great tendency to develop into
cracks), and presents much the appearance in miniature of a very roughly
ploughed field. With cordite, on the contrary, the surface appears to be
pretty smoothly swept away, while the length of the surface eroded is
considerably less."
Page 188
[Illustration: FIG. 39.—COMPARATIVE PRESSURE CURVES OF
CORDITE AND BLACK POWDER. a, Charge, 48 lbs. powder; b, charge,
13 lbs. 4 oz. cordite; c, charge, 13 lbs. 4 oz. powder. Weight of projectile,
100 lbs. in 6-inch gun. M.V. Cordite = 1960 feet seconds.]
The pressures given by cordite compared with those given by black
powder in the 6-inch gun will be seen upon reference to Fig. 39, which is
taken from Professor V.B. Lewes's paper, read before the Society of Arts;
and due to Dr W. Anderson, F.R.S., the Director-General of Ordnance
Factories.
It has been found that the erosive effect is in direct proportion to the
nitro-glycerine present. The cordite M.D., which contains only 30 per cent.
nitro-glycerine, gives only about half the erosive effect of the old service
cordite. With regard to the heating effect of cordite and cordite M.D. on a
rifle, Mr T.W. Jones made some experiments. He fired fifty rounds of .303
cartridges in fifteen minutes in the service rifle. Cordite raised the
temperature of the rifle 270° F., and cordite M.D. 160° F. only.
With regard to the effect of heat upon cordite, there is some difference of
opinion. Dr W. Anderson, F.R.S., says that there is no doubt that the effect
of heat upon cordite is greater than upon black powder. At a temperature of
110° F. the cordite used in the 4.7-inch gun is considerably affected as
regards pressure.
Colonel Barker, R.A., in reply to a question raised by Colonel Trench,
R.A. (at the Royal Artillery Institution), concerning the shooting qualities of
cordite heated to a temperature of 110° F., said: "Heating cordite and firing
it hot undoubtedly does disturb its shooting qualities, but as far as we can
see, not much more than gunpowder. I fear that we must always expect
abnormal results with heated propellants, either gunpowder or cordite; and
when fired hot, the increase in pressure and velocities will depend upon the
CORDITE AND BLACK POWDER. a, Charge, 48 lbs. powder; b, charge,
13 lbs. 4 oz. cordite; c, charge, 13 lbs. 4 oz. powder. Weight of projectile,
100 lbs. in 6-inch gun. M.V. Cordite = 1960 feet seconds.]
The pressures given by cordite compared with those given by black
powder in the 6-inch gun will be seen upon reference to Fig. 39, which is
taken from Professor V.B. Lewes's paper, read before the Society of Arts;
and due to Dr W. Anderson, F.R.S., the Director-General of Ordnance
Factories.
It has been found that the erosive effect is in direct proportion to the
nitro-glycerine present. The cordite M.D., which contains only 30 per cent.
nitro-glycerine, gives only about half the erosive effect of the old service
cordite. With regard to the heating effect of cordite and cordite M.D. on a
rifle, Mr T.W. Jones made some experiments. He fired fifty rounds of .303
cartridges in fifteen minutes in the service rifle. Cordite raised the
temperature of the rifle 270° F., and cordite M.D. 160° F. only.
With regard to the effect of heat upon cordite, there is some difference of
opinion. Dr W. Anderson, F.R.S., says that there is no doubt that the effect
of heat upon cordite is greater than upon black powder. At a temperature of
110° F. the cordite used in the 4.7-inch gun is considerably affected as
regards pressure.
Colonel Barker, R.A., in reply to a question raised by Colonel Trench,
R.A. (at the Royal Artillery Institution), concerning the shooting qualities of
cordite heated to a temperature of 110° F., said: "Heating cordite and firing
it hot undoubtedly does disturb its shooting qualities, but as far as we can
see, not much more than gunpowder. I fear that we must always expect
abnormal results with heated propellants, either gunpowder or cordite; and
when fired hot, the increase in pressure and velocities will depend upon the
Page 189
heat above the normal or average temperature at which firing takes place."
Colonel Barker also, in referring to experiments that had been made in
foreign climates, said: "Climatic trials have been carried out all over the
world, and they have so far proved eminently satisfactory. The Arctic cold
of the winter in Canada, with the temperature below zero, and the tropical
sun of India, have as yet failed to shake the stability of the composition, or
abnormally injure its shooting qualities." Dr Anderson is of opinion that
cordite should not be stored in naval magazines near to the boilers.
Professor Vivian B. Lewes, in his recent Cantor Lectures before the Society
of Arts, suggests that the magazines of warships should be water- jacketed,
and maintained at a temperature that does not rise above 100° F.
~Axite.~—This powder is manufactured by Messrs Kynock Limited, at
their works at Witton, Birmingham. The main constituents of cordite are
retained although the proportions are altered; ingredients are added which
impart properties not possessed by cordite, and the methods of its
manufacture have been modified. The form has also been altered. Axite is
made in the form of a ribbon, the cross section being similar in shape to a
double- headed rail. It is claimed for this powder, that it does not corrode
the barrel in the way cordite does, that with equal pressure it gives greatly
increased velocity, and therefore flatter trajectory. That the effect of
temperature on the pressure and velocity with axite is only half that with
cordite. That the maximum flame temperature of axite is considerably less
than that of cordite, and the erosive effect is therefore considerably less.
That the deposit left in the barrel after firing axite cartridges reduces the
friction between the bullet and the barrel. It is therefore practicable to use
axite cartridges giving higher velocities than can be employed with cordite,
as with such velocities the latter would nickel the barrel by excessive
friction. It is also claimed that the accuracy is greatly increased. The
following results have been obtained with this same time, and under the
same conditions:—
Colonel Barker also, in referring to experiments that had been made in
foreign climates, said: "Climatic trials have been carried out all over the
world, and they have so far proved eminently satisfactory. The Arctic cold
of the winter in Canada, with the temperature below zero, and the tropical
sun of India, have as yet failed to shake the stability of the composition, or
abnormally injure its shooting qualities." Dr Anderson is of opinion that
cordite should not be stored in naval magazines near to the boilers.
Professor Vivian B. Lewes, in his recent Cantor Lectures before the Society
of Arts, suggests that the magazines of warships should be water- jacketed,
and maintained at a temperature that does not rise above 100° F.
~Axite.~—This powder is manufactured by Messrs Kynock Limited, at
their works at Witton, Birmingham. The main constituents of cordite are
retained although the proportions are altered; ingredients are added which
impart properties not possessed by cordite, and the methods of its
manufacture have been modified. The form has also been altered. Axite is
made in the form of a ribbon, the cross section being similar in shape to a
double- headed rail. It is claimed for this powder, that it does not corrode
the barrel in the way cordite does, that with equal pressure it gives greatly
increased velocity, and therefore flatter trajectory. That the effect of
temperature on the pressure and velocity with axite is only half that with
cordite. That the maximum flame temperature of axite is considerably less
than that of cordite, and the erosive effect is therefore considerably less.
That the deposit left in the barrel after firing axite cartridges reduces the
friction between the bullet and the barrel. It is therefore practicable to use
axite cartridges giving higher velocities than can be employed with cordite,
as with such velocities the latter would nickel the barrel by excessive
friction. It is also claimed that the accuracy is greatly increased. The
following results have been obtained with this same time, and under the
same conditions:—
Page 190
~Axite~ Cartridges with 200-grain bullets.
Velocity 2,726 F.S.
Pressure 20.95 tons.
~Axite~ Cartridges with 215-grain bullets.
Velocity 2,498 F.S.
Pressure 19.24 tons.
~Axite~ Service Cartridges.
Velocity 2,179 F.S.
Pressure 15.76 tons.
~Cordite~ Service Cartridges.
Velocity 2,010 F.S.
Pressure 15.67 tons.
Five rounds from the Service axite and Service cordite were placed in an
oven and heated to a temperature of 110° F. for one hour, and were then
fired for pressure. The following results were obtained:—
~Axite.~ ~Cordite.~
Before heating 15.76 tons per sq. in. 15.67 tons per sq. in.
After " 16.73 " " 17.21 " "
_____ _____
Increase .97 = 6.1% 1.54 = 9.8%
Average Velocities—
Before heating 2,150 F.S. 2,030 F.S.
After " 2,180 " 2,090 "
_____ _____
Increase 30 F.S. = 1-1/2% 60.0 F.S. = 3%
Velocity 2,726 F.S.
Pressure 20.95 tons.
~Axite~ Cartridges with 215-grain bullets.
Velocity 2,498 F.S.
Pressure 19.24 tons.
~Axite~ Service Cartridges.
Velocity 2,179 F.S.
Pressure 15.76 tons.
~Cordite~ Service Cartridges.
Velocity 2,010 F.S.
Pressure 15.67 tons.
Five rounds from the Service axite and Service cordite were placed in an
oven and heated to a temperature of 110° F. for one hour, and were then
fired for pressure. The following results were obtained:—
~Axite.~ ~Cordite.~
Before heating 15.76 tons per sq. in. 15.67 tons per sq. in.
After " 16.73 " " 17.21 " "
_____ _____
Increase .97 = 6.1% 1.54 = 9.8%
Average Velocities—
Before heating 2,150 F.S. 2,030 F.S.
After " 2,180 " 2,090 "
_____ _____
Increase 30 F.S. = 1-1/2% 60.0 F.S. = 3%
Page 191
In order to show the accuracy given by axite, seven rounds were fired
from a machine rest at a target fixed at 100 yards from a rifle. Six of the
seven shots could be covered by a penny piece, the other being just outside.
In order to ascertain the relative heat imparted to a rifle by the explosion of
axite and cordite, ten rounds each of axite and cordite cartridges were fired
from a .303 rifle, at intervals of ten seconds, the temperature of the rifle
barrel being taken before and after each series:—
THE RISE IN TEMPERATURE OF THE RIFLE BARREL
With axite was 71° F.
With cordite was 89° F.
Difference in favour of axite 18° F. = 20.2%
The lubricating action of axite is shown by the fact that a series of cordite
cartridges fired from a .303 rifle in the ordinary way, followed by a second
series, the barrel being lubricated between each shot by firing an axite
cartridge alternately with the cordite cartridge. The mean velocity of the
first series of cordite cartridges was 1,974 ft. per second; the mean velocity
of the second series was 2,071 ft. per second; the increased velocity due to
the lubricating effect of axite therefore was 97 ft. per second. This powder,
it is evident, has very many very excellent qualities, and considerable
advantages over cordite. It is understood that axite is at present under the
consideration of the British Government for use as the Service powder.
~Ballistite.~—Nobel's powder, known as ballistite, originally consisted
of a camphorated blasting gelatine, and was made of 10 parts of camphor in
100 parts of nitro-glycerine, to which 200 parts of benzol were then added,
and 50 parts of nitro-cotton (soluble) were then steeped in this mixture,
which was then heated to evaporate off the benzol, and the resulting
compound afterwards passed between steam-heated rollers, and formed into
sheets, which were then finally cut up into small squares or other shapes as
from a machine rest at a target fixed at 100 yards from a rifle. Six of the
seven shots could be covered by a penny piece, the other being just outside.
In order to ascertain the relative heat imparted to a rifle by the explosion of
axite and cordite, ten rounds each of axite and cordite cartridges were fired
from a .303 rifle, at intervals of ten seconds, the temperature of the rifle
barrel being taken before and after each series:—
THE RISE IN TEMPERATURE OF THE RIFLE BARREL
With axite was 71° F.
With cordite was 89° F.
Difference in favour of axite 18° F. = 20.2%
The lubricating action of axite is shown by the fact that a series of cordite
cartridges fired from a .303 rifle in the ordinary way, followed by a second
series, the barrel being lubricated between each shot by firing an axite
cartridge alternately with the cordite cartridge. The mean velocity of the
first series of cordite cartridges was 1,974 ft. per second; the mean velocity
of the second series was 2,071 ft. per second; the increased velocity due to
the lubricating effect of axite therefore was 97 ft. per second. This powder,
it is evident, has very many very excellent qualities, and considerable
advantages over cordite. It is understood that axite is at present under the
consideration of the British Government for use as the Service powder.
~Ballistite.~—Nobel's powder, known as ballistite, originally consisted
of a camphorated blasting gelatine, and was made of 10 parts of camphor in
100 parts of nitro-glycerine, to which 200 parts of benzol were then added,
and 50 parts of nitro-cotton (soluble) were then steeped in this mixture,
which was then heated to evaporate off the benzol, and the resulting
compound afterwards passed between steam-heated rollers, and formed into
sheets, which were then finally cut up into small squares or other shapes as
Page 192
convenient. The camphor contained in this substance was, however, found
to be a disadvantage, and its use discontinued. The composition is now 50
per cent. of soluble nitro-cotton and 50 per cent. of nitro-glycerine. As
nitro-glycerine will not dissolve its own weight of nitro-cotton (even the
soluble variety), benzol is used as a solvent, but is afterwards removed from
the finished product, just as the acetone is removed from cordite. About 1
per cent. of diphenylamine is added for the purpose of increasing its
stability.
The colour of ballistite is a darkish brown. It burns in layers when
ignited, and emits sparks. The size of the cubes into which it is cut is a 0.2-
inch cube. Its density is 1.6. It is also, by means of a special machine,
prepared in the form of sheets, after being mixed in a wooden trough fitted
with double zinc plates, and subjected to the heating process by means of
hot-water pipes. It is passed between hot rollers, and rolled into sheets,
which are afterwards put through a cutting machine and granulated. Sir A.
Nobel's experiments[A] with this powder gave the following results:—The
charge used was 5 lbs. 8 oz., the size of the cubes being 0.2 inch. The mean
crusher-gauge pressure was 14.3 tons per square inch (maximum, 2,210;
minimum, 2,142), and average pressure 2,180 atmospheres. The muzzle
velocity was 2,140 foot seconds, and the muzzle energy 1,429 foot tons. A
gramme of ballistite generates 615 c.c. of permanent gases, and gives rise to
1,365 grm. units of heat. Ballistite is manufactured at Ardeer in Scotland, at
Chilworth in Surrey, and also in Italy, under the name of Filite, which is in
the form of cords instead of cubes. The ballistite made in Germany
contained more nitro-cellulose, and the finished powder was coated with
graphite. Its use has been discontinued as the Service powder in Germany,
but it is still the Service powder in Italy.
[Footnote A: Proc. Roy. Soc., vol. lii., p. 315.]
to be a disadvantage, and its use discontinued. The composition is now 50
per cent. of soluble nitro-cotton and 50 per cent. of nitro-glycerine. As
nitro-glycerine will not dissolve its own weight of nitro-cotton (even the
soluble variety), benzol is used as a solvent, but is afterwards removed from
the finished product, just as the acetone is removed from cordite. About 1
per cent. of diphenylamine is added for the purpose of increasing its
stability.
The colour of ballistite is a darkish brown. It burns in layers when
ignited, and emits sparks. The size of the cubes into which it is cut is a 0.2-
inch cube. Its density is 1.6. It is also, by means of a special machine,
prepared in the form of sheets, after being mixed in a wooden trough fitted
with double zinc plates, and subjected to the heating process by means of
hot-water pipes. It is passed between hot rollers, and rolled into sheets,
which are afterwards put through a cutting machine and granulated. Sir A.
Nobel's experiments[A] with this powder gave the following results:—The
charge used was 5 lbs. 8 oz., the size of the cubes being 0.2 inch. The mean
crusher-gauge pressure was 14.3 tons per square inch (maximum, 2,210;
minimum, 2,142), and average pressure 2,180 atmospheres. The muzzle
velocity was 2,140 foot seconds, and the muzzle energy 1,429 foot tons. A
gramme of ballistite generates 615 c.c. of permanent gases, and gives rise to
1,365 grm. units of heat. Ballistite is manufactured at Ardeer in Scotland, at
Chilworth in Surrey, and also in Italy, under the name of Filite, which is in
the form of cords instead of cubes. The ballistite made in Germany
contained more nitro-cellulose, and the finished powder was coated with
graphite. Its use has been discontinued as the Service powder in Germany,
but it is still the Service powder in Italy.
[Footnote A: Proc. Roy. Soc., vol. lii., p. 315.]
Page 193
~U.S. Naval Smokeless Powder.~—This powder is manufactured at the
U.S. Naval Torpedo Station for use in guns of all calibres in the U.S. Navy.
It is a nitro-cellulose powder, a mixture of insoluble and soluble nitro-
cellulose together with the nitrates of barium and potassium, and a small
percentage of calcium carbonate. The proportions in the case of the powder
for the 6-inch rapid-fire gun are as follows:—Mixed nitro-cellulose (soluble
and insoluble) 80 parts, barium nitrate 15 parts, potassium nitrate 4 parts,
and calcium carbonate 1 part. The percentage of nitrogen contained in the
insoluble nitro-cellulose must be 13.30±0.15, and in the soluble 11.60±0.15,
and the mean nitration strength of the mixture must be 12.75 per cent. of
nitrogen. The solvent used in making the powder is a mixture of ether (sp.
gr. 0.720) 2 parts, and alcohol (95 per cent. by volume) 1 part. The process
of manufacture is briefly as follows:[A]—The soluble and insoluble nitro-
cellulose are dried separately at a temperature from 38° to 41° C., until they
do not contain more than 0.1 per cent. of moisture. The calcium carbonate is
also finely pulverised and dried, and is added to the mixed nitro-celluloses
after they have been sifted through a 16-mesh sieve. The nitrates are next
weighed out and dissolved in hot water, and to this solution is added the
mixture of nitro-celluloses and calcium carbonate with constant stirring
until the entire mass becomes a homogeneous paste. This pasty mass is next
spread upon trays and re-dried at a temperature between 38° and 48° C.,
and when thoroughly dry it is transferred to the kneading machine. The
ether- alcohol mixture is now added, and the process of kneading begun. It
has been found by experiment that the amount of solvent required to secure
thorough incorporation is about 500 c.c. to each 500 grms. of dried paste.
To prevent loss of solvent due to evaporation, the kneading machine is
made vapour light. The mixing or kneading is continued until the resulting
greyish-yellow paste is absolutely homogeneous so far as can be detected
by the eye, which requires from three to four hours. The paste is next
treated in a preliminary press (known as the block press and is actuated by
U.S. Naval Torpedo Station for use in guns of all calibres in the U.S. Navy.
It is a nitro-cellulose powder, a mixture of insoluble and soluble nitro-
cellulose together with the nitrates of barium and potassium, and a small
percentage of calcium carbonate. The proportions in the case of the powder
for the 6-inch rapid-fire gun are as follows:—Mixed nitro-cellulose (soluble
and insoluble) 80 parts, barium nitrate 15 parts, potassium nitrate 4 parts,
and calcium carbonate 1 part. The percentage of nitrogen contained in the
insoluble nitro-cellulose must be 13.30±0.15, and in the soluble 11.60±0.15,
and the mean nitration strength of the mixture must be 12.75 per cent. of
nitrogen. The solvent used in making the powder is a mixture of ether (sp.
gr. 0.720) 2 parts, and alcohol (95 per cent. by volume) 1 part. The process
of manufacture is briefly as follows:[A]—The soluble and insoluble nitro-
cellulose are dried separately at a temperature from 38° to 41° C., until they
do not contain more than 0.1 per cent. of moisture. The calcium carbonate is
also finely pulverised and dried, and is added to the mixed nitro-celluloses
after they have been sifted through a 16-mesh sieve. The nitrates are next
weighed out and dissolved in hot water, and to this solution is added the
mixture of nitro-celluloses and calcium carbonate with constant stirring
until the entire mass becomes a homogeneous paste. This pasty mass is next
spread upon trays and re-dried at a temperature between 38° and 48° C.,
and when thoroughly dry it is transferred to the kneading machine. The
ether- alcohol mixture is now added, and the process of kneading begun. It
has been found by experiment that the amount of solvent required to secure
thorough incorporation is about 500 c.c. to each 500 grms. of dried paste.
To prevent loss of solvent due to evaporation, the kneading machine is
made vapour light. The mixing or kneading is continued until the resulting
greyish-yellow paste is absolutely homogeneous so far as can be detected
by the eye, which requires from three to four hours. The paste is next
treated in a preliminary press (known as the block press and is actuated by
Page 194
hydraulic power), where it is pressed into a cylindrical mass of uniform
density and of such dimensions as to fit it for the final or powder press. The
cylindrical masses from the block press are transferred to the final press,
whence they are forced out of a die under a pressure of about 500 lbs. per
square inch. As it emerges from the final press the powder is in the form of
a ribbon or sheet, the width and thickness of which is determined by the
dimensions of the powder chamber of the gun in which the powder is to be
used. On the inner surface of the die are ribs extending in the direction of
the powder as it emerges from the press, the object of these ribs being to
score the sheets or ribbons in the direction of their length, so that the
powder will yield uniformly to the pressure of the gases generated in the
gun during the combustion of the charge. The ribbon or sheet is next cut
into pieces of a width and length corresponding to the chamber of the gun
for which it is intended, the general rule being that the thickness of the grain
(when perfectly dry) shall be fifteen one-thousandths (.015) of the calibre of
the gun, and the length equal to the length to fit the powder chamber. Thus,
in case of the 6-inch rapid-fire gun the thickness of the grain (or sheet) is
0.09 of an inch and the length 32 inches. The sheets are next thoroughly
dried, first between sheets of porous blotting-paper under moderate pressure
and at a temperature between 15° C. and 21.5° C. for three days, and then
exposed to free circulation of the air at about 21.5° C. for seven days, and
finally subjected for a week or longer to a temperature not exceeding 38° C.
until they cease to lose weight.
[Footnote A: Lieut. W. Walke, "Lectures on Explosives," p. 330.]
The sheets, when thoroughly dried, are of a uniform yellowish-grey
colour, and of the characteristic colloidal consistency; they possess a
perfectly smooth surface, and are free from internal blisters or cracks. The
temperature of ignition of the finished powder should not be below 172° C.,
and when subjected to the heat or stability test, it is required to resist
density and of such dimensions as to fit it for the final or powder press. The
cylindrical masses from the block press are transferred to the final press,
whence they are forced out of a die under a pressure of about 500 lbs. per
square inch. As it emerges from the final press the powder is in the form of
a ribbon or sheet, the width and thickness of which is determined by the
dimensions of the powder chamber of the gun in which the powder is to be
used. On the inner surface of the die are ribs extending in the direction of
the powder as it emerges from the press, the object of these ribs being to
score the sheets or ribbons in the direction of their length, so that the
powder will yield uniformly to the pressure of the gases generated in the
gun during the combustion of the charge. The ribbon or sheet is next cut
into pieces of a width and length corresponding to the chamber of the gun
for which it is intended, the general rule being that the thickness of the grain
(when perfectly dry) shall be fifteen one-thousandths (.015) of the calibre of
the gun, and the length equal to the length to fit the powder chamber. Thus,
in case of the 6-inch rapid-fire gun the thickness of the grain (or sheet) is
0.09 of an inch and the length 32 inches. The sheets are next thoroughly
dried, first between sheets of porous blotting-paper under moderate pressure
and at a temperature between 15° C. and 21.5° C. for three days, and then
exposed to free circulation of the air at about 21.5° C. for seven days, and
finally subjected for a week or longer to a temperature not exceeding 38° C.
until they cease to lose weight.
[Footnote A: Lieut. W. Walke, "Lectures on Explosives," p. 330.]
The sheets, when thoroughly dried, are of a uniform yellowish-grey
colour, and of the characteristic colloidal consistency; they possess a
perfectly smooth surface, and are free from internal blisters or cracks. The
temperature of ignition of the finished powder should not be below 172° C.,
and when subjected to the heat or stability test, it is required to resist
Page 195
exposure to a temperature of 71° C. for thirty minutes without causing
discoloration of the test paper.
~W.A. Powder.~—This powder is made by the American Smokeless
Powder Company, and it was proposed for use in the United States Army
and Navy. It is made in several grades according to the ballistic conditions
required. It consists of insoluble gun-cotton and nitro-glycerine, together
with metallic nitrates and an organic substance used as a deterrent or
regulator. The details of its manufacture are very similar to those of cordite,
with the exception that the nitro-glycerine is dissolved in a portion of the
acetone, before it is added to the gun-cotton. The powder is pressed into
solid threads, or tubular cords or cylinders, according to the calibre of the
gun in which the powder is to be used. As the threads emerge from the press
they are received upon a canvas belt, which passes over steam-heated pipes,
and deposited in wire baskets. The larger cords or cylinders are cut into the
proper lengths and exposed upon trays in the drying-house. The powder for
small arms is granulated by cutting the threads into short cylinders, which
are subsequently tumbled, dusted, and, if not perfectly dry, again placed
upon trays in the drying- house. Before being sent away from the factory,
from five to ten lots of 500 lbs. each are mixed in a blending machine, in
order to obtain greater uniformity. The colour of the W.A. powder is very
light grey, the grains are very uniform in size, dry and hard. The powder for
larger guns is of a yellowish colour, almost translucent, and almost as hard
as vulcanite. The powder is said to be unaffected by atmospheric or climatic
conditions, to be stable, and to have given excellent ballistic results; it is not
sensitive to the impact of bullets, and when ignited burns quietly, unless
strongly confined.
Turning now to the smokeless powders, in which the chief ingredient is
nitro-cellulose in some form (either gun-cotton or nitro-lignine, &c.), one of
the first of these was Prentice's gun-cotton, which consisted of nitrated
discoloration of the test paper.
~W.A. Powder.~—This powder is made by the American Smokeless
Powder Company, and it was proposed for use in the United States Army
and Navy. It is made in several grades according to the ballistic conditions
required. It consists of insoluble gun-cotton and nitro-glycerine, together
with metallic nitrates and an organic substance used as a deterrent or
regulator. The details of its manufacture are very similar to those of cordite,
with the exception that the nitro-glycerine is dissolved in a portion of the
acetone, before it is added to the gun-cotton. The powder is pressed into
solid threads, or tubular cords or cylinders, according to the calibre of the
gun in which the powder is to be used. As the threads emerge from the press
they are received upon a canvas belt, which passes over steam-heated pipes,
and deposited in wire baskets. The larger cords or cylinders are cut into the
proper lengths and exposed upon trays in the drying-house. The powder for
small arms is granulated by cutting the threads into short cylinders, which
are subsequently tumbled, dusted, and, if not perfectly dry, again placed
upon trays in the drying- house. Before being sent away from the factory,
from five to ten lots of 500 lbs. each are mixed in a blending machine, in
order to obtain greater uniformity. The colour of the W.A. powder is very
light grey, the grains are very uniform in size, dry and hard. The powder for
larger guns is of a yellowish colour, almost translucent, and almost as hard
as vulcanite. The powder is said to be unaffected by atmospheric or climatic
conditions, to be stable, and to have given excellent ballistic results; it is not
sensitive to the impact of bullets, and when ignited burns quietly, unless
strongly confined.
Turning now to the smokeless powders, in which the chief ingredient is
nitro-cellulose in some form (either gun-cotton or nitro-lignine, &c.), one of
the first of these was Prentice's gun-cotton, which consisted of nitrated
Page 196
paper 15 parts, mixed with 85 parts of unconverted cellulose. It was rolled
into a cylinder. Another was Punshon's gun-cotton powder, which consisted
of gun-cotton soaked in a solution of sugar, and then mixed with a nitrate,
such as sodium or potassium nitrate. Barium nitrate was afterwards used,
and the material was granulated, and consisted of nitrated gun-cotton.
The explosive known as tonite, made at Faversham, was at first intended
for use as a gunpowder, but is now only used for blasting.
~The Schultze Powder.~—One of the earliest of the successful powders
introduced into this country was Schultze's powder, the invention of
Colonel Schultze, of the Prussian Artillery, and is now manufactured by the
Schultze Gunpowder Company Limited, of London. The composition of
this powder, as given in the "Dictionary of Explosives" by the late Colonel
Cundall, is as follows:—
Soluble nitro-lignine 14.83 per cent.
Insoluble " 23.36 "
Lignine (unconverted) 13.14 "
Nitrates of K and Ba 32.35 "
Paraffin 3.65 "
Matters soluble in alcohol 0.11 "
Moisture 2.56 "
This powder was the first to solve the difficulty of making a smokeless,
or nearly smokeless powder which could be used with safety and success in
small arms. Previously, gun-cotton had been tried in various forms, and in
nearly every instance disaster to the weapon had followed, owing to the
difficulty of taming the combustion to a safe degree. But about 1866
Colonel Schultze produced, as the result of experiments, a nitrated wood
fibre which gave great promise of being more pliable and more easily
regulated in its burning than gun-cotton, and this was at once introduced
into a cylinder. Another was Punshon's gun-cotton powder, which consisted
of gun-cotton soaked in a solution of sugar, and then mixed with a nitrate,
such as sodium or potassium nitrate. Barium nitrate was afterwards used,
and the material was granulated, and consisted of nitrated gun-cotton.
The explosive known as tonite, made at Faversham, was at first intended
for use as a gunpowder, but is now only used for blasting.
~The Schultze Powder.~—One of the earliest of the successful powders
introduced into this country was Schultze's powder, the invention of
Colonel Schultze, of the Prussian Artillery, and is now manufactured by the
Schultze Gunpowder Company Limited, of London. The composition of
this powder, as given in the "Dictionary of Explosives" by the late Colonel
Cundall, is as follows:—
Soluble nitro-lignine 14.83 per cent.
Insoluble " 23.36 "
Lignine (unconverted) 13.14 "
Nitrates of K and Ba 32.35 "
Paraffin 3.65 "
Matters soluble in alcohol 0.11 "
Moisture 2.56 "
This powder was the first to solve the difficulty of making a smokeless,
or nearly smokeless powder which could be used with safety and success in
small arms. Previously, gun-cotton had been tried in various forms, and in
nearly every instance disaster to the weapon had followed, owing to the
difficulty of taming the combustion to a safe degree. But about 1866
Colonel Schultze produced, as the result of experiments, a nitrated wood
fibre which gave great promise of being more pliable and more easily
regulated in its burning than gun-cotton, and this was at once introduced
Page 197
into England, and the Schultze Gunpowder Company Limited was formed
to commence its manufacture, which it did in the year 1868. During the
years from its first appearance, Schultze gunpowder has passed through
various modifications. It was first made in a small cubical grain formed by
cutting the actual fibre of timber transversely, and then breaking this veneer
into cubes. Later on improvements were introduced, and the wood fibre so
produced was crushed to a fine degree, and then reformed into small
irregular grains. Again, an advance was made in the form of the wood fibre
used, the fibre being broken down by the action of chemicals under high
temperature, and so producing an extremely pure form of woody fibre. The
next improvement was to render the grains of the powder practically
waterproof and less affected by the atmospheric influences of moisture and
dryness, and the last improvement to the process was that of hardening the
grains by means of a solvent of nitro-lignine, so as to do away with the dust
that was often formed from the rubbing of the grains during transit.
Minor modifications have from time to time also been made, in order to
meet the gradual alteration which has taken place during this long period in
the manufacture of sporting guns and cartridge cases to be used with this
powder, but through all its evolution this Company has adhered to the first
idea of using woody fibre in preference to cotton as the basis of their
smokeless powder, as experience has confirmed the original opinion that a
powder can be thus made less sensitive to occasional differences in loading,
and more satisfactory all round than when made from the cotton base. The
powder has always been regulated so that bulk for bulk it occupies the same
measure as the best black powder, and as regards its weight, just one half of
that of black.
The process of manufacture of this powder is briefly as follows:—
to commence its manufacture, which it did in the year 1868. During the
years from its first appearance, Schultze gunpowder has passed through
various modifications. It was first made in a small cubical grain formed by
cutting the actual fibre of timber transversely, and then breaking this veneer
into cubes. Later on improvements were introduced, and the wood fibre so
produced was crushed to a fine degree, and then reformed into small
irregular grains. Again, an advance was made in the form of the wood fibre
used, the fibre being broken down by the action of chemicals under high
temperature, and so producing an extremely pure form of woody fibre. The
next improvement was to render the grains of the powder practically
waterproof and less affected by the atmospheric influences of moisture and
dryness, and the last improvement to the process was that of hardening the
grains by means of a solvent of nitro-lignine, so as to do away with the dust
that was often formed from the rubbing of the grains during transit.
Minor modifications have from time to time also been made, in order to
meet the gradual alteration which has taken place during this long period in
the manufacture of sporting guns and cartridge cases to be used with this
powder, but through all its evolution this Company has adhered to the first
idea of using woody fibre in preference to cotton as the basis of their
smokeless powder, as experience has confirmed the original opinion that a
powder can be thus made less sensitive to occasional differences in loading,
and more satisfactory all round than when made from the cotton base. The
powder has always been regulated so that bulk for bulk it occupies the same
measure as the best black powder, and as regards its weight, just one half of
that of black.
The process of manufacture of this powder is briefly as follows:—
Page 198
Wood of clean growth is treated by the well-known sulphite process for
producing pure woody fibre, which is very carefully purified, and this, after
drying, is steeped in a mixture of nitric and sulphuric acids, to render it a
nitro-compound and the explosive base of the powder. This nitro compound
is carefully purified until it stands the very high purity requirements of the
Home Office, and is then ground with oxygen-bearing salts, &c., and the
whole is formed into little irregular-shaped grains of the desired size, which
grains are dried and hardened by steeping in a suitable solvent for the nitro
compound, and after finally drying, sifting, &c., the powder is stored in
magazines for several months before it is issued. When issued, a very large
blend is made of many tons weight, which ensures absolute uniformity in
the material.
There is in England a standard load adopted by every one for testing a
sporting powder; this charge is 42 grains of powder and 1-1/8 oz. No. 6 shot
—this shot fired from a 12-bore gun, patterns being taken at 40 yards, the
velocity at any required distance.
The standard muzzle velocity of Schultze gunpowder is 1,220 feet per
second.
The mean 40 yards ditto is 875 feet per second.
The mean 20 yards ditto is 1,050 feet per second.
The internal pressure not to exceed 3.5 tons.
This Company also manufactures a new form of powder, known as
Imperial Schultze. It is a powder somewhat lighter in gravity; 33 grains
occupies the bulk charge, as compared with the 42 grains of the old. It
follows in its composition much the lines of the older powder, but it is quite
free from smoke, and leaves no residue whatever.
producing pure woody fibre, which is very carefully purified, and this, after
drying, is steeped in a mixture of nitric and sulphuric acids, to render it a
nitro-compound and the explosive base of the powder. This nitro compound
is carefully purified until it stands the very high purity requirements of the
Home Office, and is then ground with oxygen-bearing salts, &c., and the
whole is formed into little irregular-shaped grains of the desired size, which
grains are dried and hardened by steeping in a suitable solvent for the nitro
compound, and after finally drying, sifting, &c., the powder is stored in
magazines for several months before it is issued. When issued, a very large
blend is made of many tons weight, which ensures absolute uniformity in
the material.
There is in England a standard load adopted by every one for testing a
sporting powder; this charge is 42 grains of powder and 1-1/8 oz. No. 6 shot
—this shot fired from a 12-bore gun, patterns being taken at 40 yards, the
velocity at any required distance.
The standard muzzle velocity of Schultze gunpowder is 1,220 feet per
second.
The mean 40 yards ditto is 875 feet per second.
The mean 20 yards ditto is 1,050 feet per second.
The internal pressure not to exceed 3.5 tons.
This Company also manufactures a new form of powder, known as
Imperial Schultze. It is a powder somewhat lighter in gravity; 33 grains
occupies the bulk charge, as compared with the 42 grains of the old. It
follows in its composition much the lines of the older powder, but it is quite
free from smoke, and leaves no residue whatever.
Page 199
~The E.G. Powder.~—This is one of the oldest of the nitro powders. It
was invented by Reid and Johnson in 1882. It is now manufactured by the
E.G. Powder Company Limited, at their factory near Dartford, Kent, and in
America by the Anglo-American E.G. Powder Company, at New Jersey.
The basis of this powder is a fine form of cellulose, derived from cotton,
carefully purified, and freed from all foreign substances, and carefully
nitrated. Its manufacture is somewhat as follows:—Pure nitro-cotton, in the
form of a fine powder, is rotated in a drum, sprinkled with water, and the
drum rotated until the nitro-cotton has taken the form of grains. The grains
are then dried and moistened with ether-alcohol, whereby the moisture is
gelatinised, and afterwards coloured with aurine, which gives them an
orange colour. They are then dried and put through a sieve, in order to
separate the grains which may have stuck together during the gelatinising
process.
Since its introduction soon after 1881, E.G. powder has undergone
considerable modifications, and is now a distinctly different product from a
practical point of view. It is now and has been since 1897 what is known as
a 33-grain powder, that is to say, the old standard charge of 3 drams by
measure for a 12-bore gun weighs 33 grains, as compared with 42 grains for
the original E.G. and other nitro powders. This improvement was effected
by a reduction of the barium nitrate and the use of nitro- cellulose of a
higher degree of nitration, and also more gelatinisation in manufacture. The
granules are very hard, and resist moisture to an extent hitherto unattainable
by any "bulk" powder.
Irregularities of pressure in loading have also a minimum effect by
reason of the hardness of the grains. The colouring matter used is aurine,
and the small quantity of nitrate used is the barium salt. The powder is
standardised for pressure velocity with Boulengé chronograph,[A] pattern
and gravimetric density by elaborate daily tests, and is continually subjected
was invented by Reid and Johnson in 1882. It is now manufactured by the
E.G. Powder Company Limited, at their factory near Dartford, Kent, and in
America by the Anglo-American E.G. Powder Company, at New Jersey.
The basis of this powder is a fine form of cellulose, derived from cotton,
carefully purified, and freed from all foreign substances, and carefully
nitrated. Its manufacture is somewhat as follows:—Pure nitro-cotton, in the
form of a fine powder, is rotated in a drum, sprinkled with water, and the
drum rotated until the nitro-cotton has taken the form of grains. The grains
are then dried and moistened with ether-alcohol, whereby the moisture is
gelatinised, and afterwards coloured with aurine, which gives them an
orange colour. They are then dried and put through a sieve, in order to
separate the grains which may have stuck together during the gelatinising
process.
Since its introduction soon after 1881, E.G. powder has undergone
considerable modifications, and is now a distinctly different product from a
practical point of view. It is now and has been since 1897 what is known as
a 33-grain powder, that is to say, the old standard charge of 3 drams by
measure for a 12-bore gun weighs 33 grains, as compared with 42 grains for
the original E.G. and other nitro powders. This improvement was effected
by a reduction of the barium nitrate and the use of nitro- cellulose of a
higher degree of nitration, and also more gelatinisation in manufacture. The
granules are very hard, and resist moisture to an extent hitherto unattainable
by any "bulk" powder.
Irregularities of pressure in loading have also a minimum effect by
reason of the hardness of the grains. The colouring matter used is aurine,
and the small quantity of nitrate used is the barium salt. The powder is
standardised for pressure velocity with Boulengé chronograph,[A] pattern
and gravimetric density by elaborate daily tests, and is continually subjected
Page 200
to severe trials for stability under various conditions of storage, the result
being that it may be kept for what in practice amount to indefinite periods
of time, either in cartridges or in bulk without any alteration being feared.
The E.C. powders are used in sporting guns. No. 1 and No. 2 E.C. are not at
present manufactured, E.C. No. 3 having taken their place entirely. Since
1890 these powders have been manufactured under the Borland-Johnson
patents, these improved powders being for some time known as the J.B.
powders. The E.C. No. 1 was superseded by the E.C. No. 2, made under the
Borland-Johnson patents, and this in its turn by the E.C. No. 3 (in 1897).
[Footnote A: Invented in 1869 by Major Le Boulengé, Belgian Artillery.
It is intended to record the mean velocity between any two points, and from
its simplicity and accuracy is largely employed. Other forms have been
invented by Capt. Bréger, French Artillerie de la Marine, and Capt. Holden,
R.A.]
~Indurite~ is the invention of Professor C.E. Munroe, of the U.S. Naval
Torpedo Station. It is made from insoluble nitro-cotton, treated in a
particular manner by steam, and mixed with nitro-benzene. The Dupont
powder is very similar to Indurite. M.E. Leonard, of the United States,
invented a powder consisting of 75 parts of nitro-glycerine, 25 parts of gun-
cotton, 5 parts of lycopodium powder, and 4 parts of urea crystals dissolved
in acetone. The French smokeless powder, Vielle poudre (poudre B), used
in the Lebel rifle, is a mixture of nitro-cellulose and tannin, mixed with
barium and potassium nitrates. It gives a very feeble report, and very little
bluish smoke. The Nobel Company is said to be perfecting a smokeless
powder in which the chief ingredients are nitro-amido- and tri- nitro-
benzene. C.O. Lundholm has patented (U.S. Pat, 701,591, 1901) a
smokeless powder containing nitro-glycerine 30, nitro-cellulose 60, diamyl
phthalate 10 (or diamyl phthalate 5, and mineral jelly 5). The diamyl
being that it may be kept for what in practice amount to indefinite periods
of time, either in cartridges or in bulk without any alteration being feared.
The E.C. powders are used in sporting guns. No. 1 and No. 2 E.C. are not at
present manufactured, E.C. No. 3 having taken their place entirely. Since
1890 these powders have been manufactured under the Borland-Johnson
patents, these improved powders being for some time known as the J.B.
powders. The E.C. No. 1 was superseded by the E.C. No. 2, made under the
Borland-Johnson patents, and this in its turn by the E.C. No. 3 (in 1897).
[Footnote A: Invented in 1869 by Major Le Boulengé, Belgian Artillery.
It is intended to record the mean velocity between any two points, and from
its simplicity and accuracy is largely employed. Other forms have been
invented by Capt. Bréger, French Artillerie de la Marine, and Capt. Holden,
R.A.]
~Indurite~ is the invention of Professor C.E. Munroe, of the U.S. Naval
Torpedo Station. It is made from insoluble nitro-cotton, treated in a
particular manner by steam, and mixed with nitro-benzene. The Dupont
powder is very similar to Indurite. M.E. Leonard, of the United States,
invented a powder consisting of 75 parts of nitro-glycerine, 25 parts of gun-
cotton, 5 parts of lycopodium powder, and 4 parts of urea crystals dissolved
in acetone. The French smokeless powder, Vielle poudre (poudre B), used
in the Lebel rifle, is a mixture of nitro-cellulose and tannin, mixed with
barium and potassium nitrates. It gives a very feeble report, and very little
bluish smoke. The Nobel Company is said to be perfecting a smokeless
powder in which the chief ingredients are nitro-amido- and tri- nitro-
benzene. C.O. Lundholm has patented (U.S. Pat, 701,591, 1901) a
smokeless powder containing nitro-glycerine 30, nitro-cellulose 60, diamyl
phthalate 10 (or diamyl phthalate 5, and mineral jelly 5). The diamyl
Page 201
phthalate is added, with or without the mineral jelly to nitro-glycerine and
nitro-cellulose.
~Walsrode Powder.~—The smokeless powder known as Walsrode
powder consists of absolutely pure gelatinised nitro-cellulose, grained by a
chemical not a mechanical process, consequently the grains do not need
facing with gelatine to prevent their breaking up, as is the case with many
nitro powders. For this same reason, as well as from the method of getting
rid of the solvent used, the Walsrode has no tendency whatever to absorb
moisture. In fact, it can lie in water for several days, and when taken out
and dried again at a moderate temperature will be found as good as before.
Nor is it influenced by heat, whether dry or damp, and it can be stored for
years without being in the least affected. It is claimed also that it heats the
barrels of guns much less than black powder, and does not injure them.
The standard charge is 30 grains, and it is claimed that with this charge
Walsrode powder will prove second to none. A large cap is necessary, as the
grains of this powder are very hard, and require a large flame to properly
ignite them. In loading cartridges for sporting purposes, an extra felt wad is
required to compensate for the small space occupied by the charge; but for
military use the powder can be left quite loose. The gas pressure of this
powder is low (in several military rifles only one- half that of other nitros),
and the recoil consequently small; and it is claimed that with the slight
increase of the charge (from 29 to 30 grs.) both penetration and initial
velocity will be largely increased, whilst the gas pressure and recoil will not
be greater.
This powder was used at Bisley, at the National Rifle Association's
Meeting, with satisfactory results. It is made by the Walsrode Smokeless
and Waterproof Gunpowder Company. The nitro-cotton is gelatinised by
means of acetic ether, and the skin produced retards burning. The nitro-
nitro-cellulose.
~Walsrode Powder.~—The smokeless powder known as Walsrode
powder consists of absolutely pure gelatinised nitro-cellulose, grained by a
chemical not a mechanical process, consequently the grains do not need
facing with gelatine to prevent their breaking up, as is the case with many
nitro powders. For this same reason, as well as from the method of getting
rid of the solvent used, the Walsrode has no tendency whatever to absorb
moisture. In fact, it can lie in water for several days, and when taken out
and dried again at a moderate temperature will be found as good as before.
Nor is it influenced by heat, whether dry or damp, and it can be stored for
years without being in the least affected. It is claimed also that it heats the
barrels of guns much less than black powder, and does not injure them.
The standard charge is 30 grains, and it is claimed that with this charge
Walsrode powder will prove second to none. A large cap is necessary, as the
grains of this powder are very hard, and require a large flame to properly
ignite them. In loading cartridges for sporting purposes, an extra felt wad is
required to compensate for the small space occupied by the charge; but for
military use the powder can be left quite loose. The gas pressure of this
powder is low (in several military rifles only one- half that of other nitros),
and the recoil consequently small; and it is claimed that with the slight
increase of the charge (from 29 to 30 grs.) both penetration and initial
velocity will be largely increased, whilst the gas pressure and recoil will not
be greater.
This powder was used at Bisley, at the National Rifle Association's
Meeting, with satisfactory results. It is made by the Walsrode Smokeless
and Waterproof Gunpowder Company. The nitro-cotton is gelatinised by
means of acetic ether, and the skin produced retards burning. The nitro-
Page 202
cotton is mixed with acetic ether, and when the gelatinisation has taken
place, the plastic mass is forced through holes in a metal plate into strips,
which are then cut up into pieces the size of grains. The M.H. Walsrode
powder is a leaflet powder, light in colour, about 40 grains of which give a
muzzle velocity of 1,350 feet and a pressure of 3 tons. It is, like the other
Walsrode powders, waterproof and heat-proof.
~Cooppal Powder~ is manufactured by Messrs Cooppal & Co. at their
extensive powder works in Belgium. It consists of nitro-jute or nitro-
cotton, with or without nitrates, treated with a solvent to form a gelatinised
mass. There are a great many varieties of this powder. One kind is in the
form of little squares; another, for use in Hotchkiss guns, is formed into 3-
millimetre cubes, and is black. Other varieties are coloured with aniline
dyes of different colours.
~Amberite~ is a nitro-cellulose powder of the 42-grain type of sporting
gunpowders, and is manufactured by Messrs Curtis's & Harvey Limited, at
their Smokeless Powder Factory, Tonbridge, Kent. It consists of a mixture
of nitro-cellulose, paraffin, barium, nitrate, and some other ingredients. It is
claimed for this powder that it combines hard shooting with safety, great
penetration, and moderate strain on the gun. It is hard and tough in grain,
and may be loaded like black powder, and subjected to hard friction without
breaking into powder, that it is smokeless, and leaves no residue in the gun.
The charge for 12 bores is 42 grains by weight, and 1-1/8 oz. or 1-1/16 oz.
shot. The powders known as cannonite[A] and ruby powder, also
manufactured by Messrs Curtis's & Harvey Limited, are analogous products
having the same general characteristics.
[Footnote A: For further details of cannonite, see First Edition, p. 181.]
~Smokeless Diamond~, also manufactured by the above mentioned firm,
is a nitro-cellulose powder of the 33-grain type of sporting gunpowders. It
place, the plastic mass is forced through holes in a metal plate into strips,
which are then cut up into pieces the size of grains. The M.H. Walsrode
powder is a leaflet powder, light in colour, about 40 grains of which give a
muzzle velocity of 1,350 feet and a pressure of 3 tons. It is, like the other
Walsrode powders, waterproof and heat-proof.
~Cooppal Powder~ is manufactured by Messrs Cooppal & Co. at their
extensive powder works in Belgium. It consists of nitro-jute or nitro-
cotton, with or without nitrates, treated with a solvent to form a gelatinised
mass. There are a great many varieties of this powder. One kind is in the
form of little squares; another, for use in Hotchkiss guns, is formed into 3-
millimetre cubes, and is black. Other varieties are coloured with aniline
dyes of different colours.
~Amberite~ is a nitro-cellulose powder of the 42-grain type of sporting
gunpowders, and is manufactured by Messrs Curtis's & Harvey Limited, at
their Smokeless Powder Factory, Tonbridge, Kent. It consists of a mixture
of nitro-cellulose, paraffin, barium, nitrate, and some other ingredients. It is
claimed for this powder that it combines hard shooting with safety, great
penetration, and moderate strain on the gun. It is hard and tough in grain,
and may be loaded like black powder, and subjected to hard friction without
breaking into powder, that it is smokeless, and leaves no residue in the gun.
The charge for 12 bores is 42 grains by weight, and 1-1/8 oz. or 1-1/16 oz.
shot. The powders known as cannonite[A] and ruby powder, also
manufactured by Messrs Curtis's & Harvey Limited, are analogous products
having the same general characteristics.
[Footnote A: For further details of cannonite, see First Edition, p. 181.]
~Smokeless Diamond~, also manufactured by the above mentioned firm,
is a nitro-cellulose powder of the 33-grain type of sporting gunpowders. It
Page 203
was invented by Mr H.M. Chapman. The manufacture of Smokeless
Diamond, as carried out at Tonbridge, is shortly as follows:—The gun-
cotton, which is the chief ingredient of this powder, is first stoved, then
mixed with certain compounds which act as moderators, and after the
solvents are added, is worked up into a homogeneous plastic condition. It
then undergoes the processes of granulation, sifting, dusting, drying, and
glazing. In order to ensure uniformity several batches are blended together,
and stored for some time before being issued for use.
It is claimed for this powder that it is quick of ignition, the quickness
being probably due to the peculiar structure of the grains which, when
looked at under the microscope, have the appearance of coke. The charge
for a 12 bore is 33 grains and 1-1/16 oz. shot, which gives a velocity of
1,050 feet per second, and a pressure of 3 tons per square inch.
~Greiner's Powder~ consists of nitro-cellulose, nitro-benzol, graphite,
and lampblack.
~B.N. Powder.~—This powder is of a light grey or drab colour, perfectly
opaque, and rough to the touch. It consists of a mixture, nitro-cellulose and
the nitrates of barium and potassium. Its composition is as follows:—
Insoluble nitro-cellulose 29.13 parts
Soluble nitro-cellulose 41.31 "
Barium nitrate 19.00 "
Potassium nitrate 7.97 "
Sodium carbonate 2.03 "
Volatile matter 1.43 "
This powder is a modification of the Poudre B., or Vieille's powder
invented for use in the Lebel rifle, and which consisted of a mixture of the
nitro-celluloses with paraffin.
Diamond, as carried out at Tonbridge, is shortly as follows:—The gun-
cotton, which is the chief ingredient of this powder, is first stoved, then
mixed with certain compounds which act as moderators, and after the
solvents are added, is worked up into a homogeneous plastic condition. It
then undergoes the processes of granulation, sifting, dusting, drying, and
glazing. In order to ensure uniformity several batches are blended together,
and stored for some time before being issued for use.
It is claimed for this powder that it is quick of ignition, the quickness
being probably due to the peculiar structure of the grains which, when
looked at under the microscope, have the appearance of coke. The charge
for a 12 bore is 33 grains and 1-1/16 oz. shot, which gives a velocity of
1,050 feet per second, and a pressure of 3 tons per square inch.
~Greiner's Powder~ consists of nitro-cellulose, nitro-benzol, graphite,
and lampblack.
~B.N. Powder.~—This powder is of a light grey or drab colour, perfectly
opaque, and rough to the touch. It consists of a mixture, nitro-cellulose and
the nitrates of barium and potassium. Its composition is as follows:—
Insoluble nitro-cellulose 29.13 parts
Soluble nitro-cellulose 41.31 "
Barium nitrate 19.00 "
Potassium nitrate 7.97 "
Sodium carbonate 2.03 "
Volatile matter 1.43 "
This powder is a modification of the Poudre B., or Vieille's powder
invented for use in the Lebel rifle, and which consisted of a mixture of the
nitro-celluloses with paraffin.
Page 204
~Von Foster's Powder~ contains nothing but pure gelatinised nitro-
cellulose, together with a small quantity of carbonate of lime.
The German ~Troisdorf Powder~ is a mixture of gelatinised nitro-
cellulose, with or without nitrates.
~Maximite~ is the invention of Mr Hudson Maxim, and is a nitro-
compound, the base being gun-cotton. The exact composition and method
of manufacture are, however, kept secret. It is made by the Columbia
Powder Manufacturing Company, of New York, and in two forms—one for
use as a smokeless rifle powder, and the other for blasting purposes.
~Wetteren Powder.~—This powder was manufactured at the Royal
Gunpowder Factory at Wetteren, and used in the Belgian service. Originally
it was a mixture of nitro-glycerine and nitro-cellulose, with amyl acetate as
solvent. Its composition has, however, been altered from time to time. One
variety consists chiefly of nitro-cellulose, with amyl acetate as solvent. It is
of a dark brown colour, and of the consistency of indiarubber. It is rolled
into sheets and finally granulated.
~Henrite~ is a nitro-cellulose powder.
~Normal Powder.~—The Swedish powder known as "Normal"
Smokeless Powder, and manufactured by the Swedish Powder
Manufacturing Company, of Landskrona, Sweden, and used for some years
past in the Swiss Army, is made in four forms. For field guns of 8.4 calibre,
it is used in the form of cylindrical grains of a yellow colour, of a diameter
of .8 to .9 mm. and density of .790—about 840 grains of it go to one gun.
For rifles, it is used in the form of grey squares, density .750, and 1 grm.
equals about 1,014 grains. One hundred rounds of this powder, fired in
eighteen minutes, raised the temperature of the gun barrel 284° F. A nitro-
cellulose, together with a small quantity of carbonate of lime.
The German ~Troisdorf Powder~ is a mixture of gelatinised nitro-
cellulose, with or without nitrates.
~Maximite~ is the invention of Mr Hudson Maxim, and is a nitro-
compound, the base being gun-cotton. The exact composition and method
of manufacture are, however, kept secret. It is made by the Columbia
Powder Manufacturing Company, of New York, and in two forms—one for
use as a smokeless rifle powder, and the other for blasting purposes.
~Wetteren Powder.~—This powder was manufactured at the Royal
Gunpowder Factory at Wetteren, and used in the Belgian service. Originally
it was a mixture of nitro-glycerine and nitro-cellulose, with amyl acetate as
solvent. Its composition has, however, been altered from time to time. One
variety consists chiefly of nitro-cellulose, with amyl acetate as solvent. It is
of a dark brown colour, and of the consistency of indiarubber. It is rolled
into sheets and finally granulated.
~Henrite~ is a nitro-cellulose powder.
~Normal Powder.~—The Swedish powder known as "Normal"
Smokeless Powder, and manufactured by the Swedish Powder
Manufacturing Company, of Landskrona, Sweden, and used for some years
past in the Swiss Army, is made in four forms. For field guns of 8.4 calibre,
it is used in the form of cylindrical grains of a yellow colour, of a diameter
of .8 to .9 mm. and density of .790—about 840 grains of it go to one gun.
For rifles, it is used in the form of grey squares, density .750, and 1 grm.
equals about 1,014 grains. One hundred rounds of this powder, fired in
eighteen minutes, raised the temperature of the gun barrel 284° F. A nitro-
Page 205
glycerine powder, fired under the same conditions, gave a temperature of
464° F.
This powder is said to keep well—a sample kept 3-1/2 years gave as
good results as when first made—is easy to make, very stable, ignites
easily, not very sensitive to shock or friction, is very light, &c. Eight
hundred rounds fired from a heavy gun produced no injury to the interior of
the weapon. Samples kept for eleven months in the moist atmosphere of a
cellar, when fired gave a muzzle velocity of 1,450 ft. secs. and pressure of
1,312 atmospheres, and the moisture was found to have risen from 1.2 to
1.6 per cent. After twenty-three months in the damp it contained 2 per cent.
moisture, gave a muzzle velocity of 1,478 ft. sees., and pressure of 1,356
atmospheres. In a 7.5 millimetre rifle, 13.8 grm. bullet, and charge of 2
grms., it gives a muzzle velocity of 2,035 ft. secs. and a pressure of 2,200
atmospheres. In the 8.4 cm. field-gun, with charge of 600 grms., and
projectile of 6.7 kilogrammes, muzzle velocity was equal to 1,640 ft. secs.
and pressure 1,750. A sample of the powder for use in the .303 M. rifle,
lately analysed by the author, gave the following result:—
Gun-cotton 96.21 per cent.
Soluble cotton 1.80 "
Non-nitrated cotton trace.
Resin and other matters 1.99 "
_______
100.00
The various forms of powder invented and manufactured by Mr C.F.
Hengst are chiefly composed of nitrated straw that has been finely pulped.
The straw is treated first with acids and afterwards with alkalies, and the
result is a firm fibrous substance which is granulated. It is claimed that this
powder is entirely smokeless and flameless, that it does not foul the gun nor
464° F.
This powder is said to keep well—a sample kept 3-1/2 years gave as
good results as when first made—is easy to make, very stable, ignites
easily, not very sensitive to shock or friction, is very light, &c. Eight
hundred rounds fired from a heavy gun produced no injury to the interior of
the weapon. Samples kept for eleven months in the moist atmosphere of a
cellar, when fired gave a muzzle velocity of 1,450 ft. secs. and pressure of
1,312 atmospheres, and the moisture was found to have risen from 1.2 to
1.6 per cent. After twenty-three months in the damp it contained 2 per cent.
moisture, gave a muzzle velocity of 1,478 ft. sees., and pressure of 1,356
atmospheres. In a 7.5 millimetre rifle, 13.8 grm. bullet, and charge of 2
grms., it gives a muzzle velocity of 2,035 ft. secs. and a pressure of 2,200
atmospheres. In the 8.4 cm. field-gun, with charge of 600 grms., and
projectile of 6.7 kilogrammes, muzzle velocity was equal to 1,640 ft. secs.
and pressure 1,750. A sample of the powder for use in the .303 M. rifle,
lately analysed by the author, gave the following result:—
Gun-cotton 96.21 per cent.
Soluble cotton 1.80 "
Non-nitrated cotton trace.
Resin and other matters 1.99 "
_______
100.00
The various forms of powder invented and manufactured by Mr C.F.
Hengst are chiefly composed of nitrated straw that has been finely pulped.
The straw is treated first with acids and afterwards with alkalies, and the
result is a firm fibrous substance which is granulated. It is claimed that this
powder is entirely smokeless and flameless, that it does not foul the gun nor
Page 206
heat the barrel, and is at the same time 150 per cent. stronger than black
powder.
The German "Troisdorf" powder consists of nitro-cellulose that has been
gelatinised together with a nitrate. Kolf's powder is also gelatinised with
nitro-cellulose. The powders invented by Mr E.J. Ryves contain nitro-
glycerine, nitro-cotton, castor-oil, paper-pulp, and carbonate of magnesia.
Maxim powder contains both soluble and insoluble nitro- cellulose, nitro-
glycerine, and carbonate of soda. The smokeless powder made by the
"Dynamite Actiengesellschaft Nobel" consists of nitro-starch 70 to 99 parts,
and of di- or tri-nitro-benzene 1 to 30 parts.
An American wood powder, known as Bracket's Sporting Powder,
consists of soluble and insoluble nitro-lignine, mixed with charred lignine,
humus, and nitrate of soda. Mr F.H. Snyder, of New York, is the inventor of
a shell powder known as the "Snyder Explosive," consisting of 94 per cent.
nitro-glycerine, 6 per cent. of soluble nitro-cotton, and camphor, which is
said to be safe in use. Experiments were made with it in a 6-inch rifled gun,
fired at a target 220 yards away, composed of twelve 1-inch steel plates
welded together, and backed with 12-inch and 14-inch oak beams, and
weighing 20 tons. The shots entirely destroyed it. The charge of explosive
used was 10 lbs. in each shell.
~Comparative Tests of Black and Nitro Powders, from "American
Field."~— The results given in table below were obtained at the German
Shooting Association's grounds at Coepenick, Berlin. Penetration was
calculated by placing frames, each holding five cards of 1 millimetre in
thickness (equals .03937 inch), and 3 inches apart, in a bee-line, at distances
of 20 inches. Velocity, pattern, and penetration were taken at 40 yards from
the muzzle of a 12-gauge choke-bore double-barrel gun. Gas pressure was
taken by a special apparatus. All shells were loaded with 1-1/8 oz. of No. 3
powder.
The German "Troisdorf" powder consists of nitro-cellulose that has been
gelatinised together with a nitrate. Kolf's powder is also gelatinised with
nitro-cellulose. The powders invented by Mr E.J. Ryves contain nitro-
glycerine, nitro-cotton, castor-oil, paper-pulp, and carbonate of magnesia.
Maxim powder contains both soluble and insoluble nitro- cellulose, nitro-
glycerine, and carbonate of soda. The smokeless powder made by the
"Dynamite Actiengesellschaft Nobel" consists of nitro-starch 70 to 99 parts,
and of di- or tri-nitro-benzene 1 to 30 parts.
An American wood powder, known as Bracket's Sporting Powder,
consists of soluble and insoluble nitro-lignine, mixed with charred lignine,
humus, and nitrate of soda. Mr F.H. Snyder, of New York, is the inventor of
a shell powder known as the "Snyder Explosive," consisting of 94 per cent.
nitro-glycerine, 6 per cent. of soluble nitro-cotton, and camphor, which is
said to be safe in use. Experiments were made with it in a 6-inch rifled gun,
fired at a target 220 yards away, composed of twelve 1-inch steel plates
welded together, and backed with 12-inch and 14-inch oak beams, and
weighing 20 tons. The shots entirely destroyed it. The charge of explosive
used was 10 lbs. in each shell.
~Comparative Tests of Black and Nitro Powders, from "American
Field."~— The results given in table below were obtained at the German
Shooting Association's grounds at Coepenick, Berlin. Penetration was
calculated by placing frames, each holding five cards of 1 millimetre in
thickness (equals .03937 inch), and 3 inches apart, in a bee-line, at distances
of 20 inches. Velocity, pattern, and penetration were taken at 40 yards from
the muzzle of a 12-gauge choke-bore double-barrel gun. Gas pressure was
taken by a special apparatus. All shells were loaded with 1-1/8 oz. of No. 3
Page 207
shot, equal to 120 pellets, and the number given below represents the
average number in the 30-inch pattern. The number of sheets passed
through gives the average penetration. One atmosphere equals pressure
equal to 1 kilogramme (2.2 lbs.) on the square centimetre, hence 1,000
atmospheres equal 2,200 lbs. on the square centimetre. The E.C., Schultze,
and Walsrode powders were loaded in Elcy's special shells, 2-1/2 inches
long. The averages were taken from a large number of shots, and the same
series of shots fired under precisely the same conditions.
___________________________________________________________
____________ | | | | | | | | Gas | | | | | | Pressure. | Velocity. | Pattern. |
Penetration. |
|__________________|____________|___________|____________|______
________| | | | | | | | |Atmospheres.| Metres. | | Sheets. | | | | | | | |Fine-grained
black| | | | | |powder, standard | | | | | |charge | 514.2 | 280 | 78.6 = 66% | 19.O |
| | | | | | |Coarse-grained | | | | | |black powder, | | | | | |standard charge | 473.4 |
281.4 | 78.2 = 65% | 19.4 | | | | | | | |Schultze powder, | | | | | |42 grains | 921.0 |
290.0 | 64.2 = 54% | 20.2 | | | | | | | |Schultze powder, | | | | | |45 grains | 1052.8
| 305.8 | 52.2 = 42% | 20.6 | | | | | | | |E.G. smokeless, | | | | | |42 grains | 920.2 |
298.4 | 81.4 = 67% | 18.8 | | | | | | | |Walsrode, | | | | | |29 grains | 586.4 | 280.6 |
83.0 = 69% | 19.0 |
|__________________|____________|___________|____________|______
________|
Barometer, 760 mm. Thermometer, 30° C. Hydrometer = 65. Wind, S.W.
~Picric Powders.~—The chief of these is Melinite, the composition of
which is not known with certainty. It is believed to be melted picric acid
together with gun-cotton dissolved in acetone or ether-alcohol. Walke gives
the following proportions—30 parts of tri-nitro-cellulose dissolved in 45
parts of ether-alcohol (2 to 1), and 70 parts of fused and pulverised picric
average number in the 30-inch pattern. The number of sheets passed
through gives the average penetration. One atmosphere equals pressure
equal to 1 kilogramme (2.2 lbs.) on the square centimetre, hence 1,000
atmospheres equal 2,200 lbs. on the square centimetre. The E.C., Schultze,
and Walsrode powders were loaded in Elcy's special shells, 2-1/2 inches
long. The averages were taken from a large number of shots, and the same
series of shots fired under precisely the same conditions.
___________________________________________________________
____________ | | | | | | | | Gas | | | | | | Pressure. | Velocity. | Pattern. |
Penetration. |
|__________________|____________|___________|____________|______
________| | | | | | | | |Atmospheres.| Metres. | | Sheets. | | | | | | | |Fine-grained
black| | | | | |powder, standard | | | | | |charge | 514.2 | 280 | 78.6 = 66% | 19.O |
| | | | | | |Coarse-grained | | | | | |black powder, | | | | | |standard charge | 473.4 |
281.4 | 78.2 = 65% | 19.4 | | | | | | | |Schultze powder, | | | | | |42 grains | 921.0 |
290.0 | 64.2 = 54% | 20.2 | | | | | | | |Schultze powder, | | | | | |45 grains | 1052.8
| 305.8 | 52.2 = 42% | 20.6 | | | | | | | |E.G. smokeless, | | | | | |42 grains | 920.2 |
298.4 | 81.4 = 67% | 18.8 | | | | | | | |Walsrode, | | | | | |29 grains | 586.4 | 280.6 |
83.0 = 69% | 19.0 |
|__________________|____________|___________|____________|______
________|
Barometer, 760 mm. Thermometer, 30° C. Hydrometer = 65. Wind, S.W.
~Picric Powders.~—The chief of these is Melinite, the composition of
which is not known with certainty. It is believed to be melted picric acid
together with gun-cotton dissolved in acetone or ether-alcohol. Walke gives
the following proportions—30 parts of tri-nitro-cellulose dissolved in 45
parts of ether-alcohol (2 to 1), and 70 parts of fused and pulverised picric
Page 208
acid. The ether-alcohol mixture is allowed to evaporate spontaneously, and
the resulting cake granulated. The French claim, however, that the original
invention has been so modified and perfected that the melinite of to-day
cannot be recognised in the earlier product. Melinite has a yellow colour, is
almost without crystalline appearance, and when ignited by a flame or
heated wire, it burns with a reddish-yellow flame, giving off copious
volumes of black smoke. Melinite as at present used is said to be a perfectly
safe explosive, both as regards manufacture, handling, and storage.
Lyddite,[A] the picric acid explosive used in the British service, is
supposed to be identical with the original melinite, but its composition has
not been made public.
[Footnote A: Schimose, the Japanese powder, is stated to be identical
with
Lyddite and Melinite (Chem. Centr., 1906, 1, 1196).]
Picrates are more often used than picric acid itself in powders. One of the
best known is Brugère's Powder, which is a mixture of 54 parts of picrate of
ammonia and 45 parts of saltpetre. It is stable and safe to manufacture. It
has been used in the Chassepôt rifle with good results, gives little smoke,
and a small residue only of carbonate of potash.
The next in importance is Designolle's Powder, made at Bouchon,
consisting of picrate of potash, saltpetre, and charcoal. It was made in three
varieties, viz., for rifles, big guns, and torpedoes and shells. These powders
are made much in the same way as gunpowder. The advantages claimed for
them over gunpowder are, greater strength, comparative absence of smoke,
and freedom from injurious action on the bores of guns.
Emmensite is the invention of Dr Stephen Emmens, of the United States.
The Emmens "crystals" are produced by treating picric acid with fuming
the resulting cake granulated. The French claim, however, that the original
invention has been so modified and perfected that the melinite of to-day
cannot be recognised in the earlier product. Melinite has a yellow colour, is
almost without crystalline appearance, and when ignited by a flame or
heated wire, it burns with a reddish-yellow flame, giving off copious
volumes of black smoke. Melinite as at present used is said to be a perfectly
safe explosive, both as regards manufacture, handling, and storage.
Lyddite,[A] the picric acid explosive used in the British service, is
supposed to be identical with the original melinite, but its composition has
not been made public.
[Footnote A: Schimose, the Japanese powder, is stated to be identical
with
Lyddite and Melinite (Chem. Centr., 1906, 1, 1196).]
Picrates are more often used than picric acid itself in powders. One of the
best known is Brugère's Powder, which is a mixture of 54 parts of picrate of
ammonia and 45 parts of saltpetre. It is stable and safe to manufacture. It
has been used in the Chassepôt rifle with good results, gives little smoke,
and a small residue only of carbonate of potash.
The next in importance is Designolle's Powder, made at Bouchon,
consisting of picrate of potash, saltpetre, and charcoal. It was made in three
varieties, viz., for rifles, big guns, and torpedoes and shells. These powders
are made much in the same way as gunpowder. The advantages claimed for
them over gunpowder are, greater strength, comparative absence of smoke,
and freedom from injurious action on the bores of guns.
Emmensite is the invention of Dr Stephen Emmens, of the United States.
The Emmens "crystals" are produced by treating picric acid with fuming
Page 209
nitric acid of specific gravity of 1.52. The acid dissolves with the evolution
of red fumes. The liquid, when cooled, deposits crystals, stated to be
different to picric acid, and lustrous flakes. These flakes, when heated in
water, separate into two new bodies. One of these enters into solution and
forms crystals unlike the first, while the other body remains undissolved.
The acid crystals are used mixed with a nitrate.
Emmensite has been subjected to experiment by the direction of the U.S.
Secretary for War, and found satisfactory. A sample of Emmensite, in the
form of a coarse powder, was first tried in a pistol, and proved superior in
propelling power to ordinary gunpowder. When tested against explosive
gelatine, it did very good work in shattering iron plates. It is claimed for
this explosive that it enjoys the distinction of being the only high explosive
which may be used both for firearms and blasting. This view is supported
by the trials made by the American War Office authorities, and shows
Emmensite to be a useful explosive both for blasting and as a smokeless
powder. Its explosive power, as tested, is 283 tons per square inch, and its
specific gravity is 1.8.
Abel proposed to use picric acid for filling shells. His Picric Powder
consisted of 3 parts of saltpetre, and 2 of picrate of ammonia. Victorite
consists of chlorate of potash, picric acid, and olive oil, and with
occasionally some charcoal. It has the form of a coarse yellowish grey
powder, and leaves an oily stain on paper, and it is very sensitive to friction
and percussion. The composition is as follows:—KClO_{3} = 80 parts;
picric acid, 110 parts; saltpetre, 10 parts; charcoal, 5 parts. It is not
manufactured in England. Tschiner's Powder is very similar to Victorite in
composition, but contains resin. A list of the chief picric powders will be
found in the late Colonel J.P. Cundill, R.A.'s "Dictionary of Explosives."
of red fumes. The liquid, when cooled, deposits crystals, stated to be
different to picric acid, and lustrous flakes. These flakes, when heated in
water, separate into two new bodies. One of these enters into solution and
forms crystals unlike the first, while the other body remains undissolved.
The acid crystals are used mixed with a nitrate.
Emmensite has been subjected to experiment by the direction of the U.S.
Secretary for War, and found satisfactory. A sample of Emmensite, in the
form of a coarse powder, was first tried in a pistol, and proved superior in
propelling power to ordinary gunpowder. When tested against explosive
gelatine, it did very good work in shattering iron plates. It is claimed for
this explosive that it enjoys the distinction of being the only high explosive
which may be used both for firearms and blasting. This view is supported
by the trials made by the American War Office authorities, and shows
Emmensite to be a useful explosive both for blasting and as a smokeless
powder. Its explosive power, as tested, is 283 tons per square inch, and its
specific gravity is 1.8.
Abel proposed to use picric acid for filling shells. His Picric Powder
consisted of 3 parts of saltpetre, and 2 of picrate of ammonia. Victorite
consists of chlorate of potash, picric acid, and olive oil, and with
occasionally some charcoal. It has the form of a coarse yellowish grey
powder, and leaves an oily stain on paper, and it is very sensitive to friction
and percussion. The composition is as follows:—KClO_{3} = 80 parts;
picric acid, 110 parts; saltpetre, 10 parts; charcoal, 5 parts. It is not
manufactured in England. Tschiner's Powder is very similar to Victorite in
composition, but contains resin. A list of the chief picric powders will be
found in the late Colonel J.P. Cundill, R.A.'s "Dictionary of Explosives."
Page 210
CHAPTER VII.
ANALYSIS OF EXPLOSIVES.
Kieselguhr Dynamite—Gelatine Compounds—Tonite—Cordite—
Vaseline—
Acetone—Scheme for Analysis of Explosives—Nitro-Cotton—Solubility
Test—
Non-Nitrated Cotton—Alkalinity—Ash and Inorganic Matter—
Determination
of Nitrogen—Lungé, Champion and Pellet's, Schultze-Tieman, and
Kjeldahl's
Methods—Celluloid—Picric Acid and Picrates—Resinous and Tarry
Matters—
Sulphuric Acid and Hydrochloric Acid and Oxalic Acid—Nitric Acid—
Inorganic Impurities—General Impurities and Adulterations—Potassium
Picrate, &c.—Picrates of the Alkaloids—Analysis of Glycerine—Residue
—
Silver Test—Nitration—Total Acid Equivalent—Neutrality—Free Fatty
Acids—Combined Fatty Acids—Impurities—Oleic Acid—Sodium
Chloride—
Determination of Glycerine—Waste Acids—Sodium Nitrate—Mercury
Fulminate—Cap Composition—Table for Correction of Volumes of Gases,
for
Temperature and Pressure
ANALYSIS OF EXPLOSIVES.
Kieselguhr Dynamite—Gelatine Compounds—Tonite—Cordite—
Vaseline—
Acetone—Scheme for Analysis of Explosives—Nitro-Cotton—Solubility
Test—
Non-Nitrated Cotton—Alkalinity—Ash and Inorganic Matter—
Determination
of Nitrogen—Lungé, Champion and Pellet's, Schultze-Tieman, and
Kjeldahl's
Methods—Celluloid—Picric Acid and Picrates—Resinous and Tarry
Matters—
Sulphuric Acid and Hydrochloric Acid and Oxalic Acid—Nitric Acid—
Inorganic Impurities—General Impurities and Adulterations—Potassium
Picrate, &c.—Picrates of the Alkaloids—Analysis of Glycerine—Residue
—
Silver Test—Nitration—Total Acid Equivalent—Neutrality—Free Fatty
Acids—Combined Fatty Acids—Impurities—Oleic Acid—Sodium
Chloride—
Determination of Glycerine—Waste Acids—Sodium Nitrate—Mercury
Fulminate—Cap Composition—Table for Correction of Volumes of Gases,
for
Temperature and Pressure
Page 211
~Kieselguhr Dynamite.~—The material generally consists of 75 per cent.
of nitro-glycerine and 25 per cent. of the infusorial earth kieselguhr. The
analysis is very simple, and may be conducted as follows:—Weigh out
about 10 grms. of the substance, and place over calcium chloride in a
desiccator for some six to eight days, and then re-weigh. The loss of weight
gives the moisture. This will generally be very small, probably never more
than 1 per cent., and usually less.
Mr James O. Handy, in order to save time, proposes to dry dynamite in
the following manner. He places 1 grm. of the material in a porcelain
crucible 1 inch in diameter. The crucible is then supported at the bottom of
an extra wide-mouthed bottle of about 600 c.c. capacity. Air, which has
been dried by bubbling through strong sulphuric acid, is now drawn over
the surface of the sample for three hours by means of an ordinary aspirator.
The air should pass approximately at the rate of 10 c.c. per second. The tube
by which the dry air enters the bottle extends to within 1 inch of the
crucible containing the dynamite. An empty safety bottle is connected with
the inlet, and another with the outlet of the wide-mouthed bottle. The first
guards against the mechanical carrying over by the air current of sulphuric
acid from the acid bottle into the sample, whilst the second prevents
spasmodic outbursts of water from the exhaust from reaching the sample.
The method also gave satisfactory results with nitro-glycerine. The dry
substance may now be wrapped in filter paper, the whole weighed, and the
nitro-glycerine extracted in the Soxhlet apparatus with ether. The ether
should be distilled over at least twenty-four times.
I have found, however, that much quicker, and quite as accurate, results
may be obtained by leaving the dynamite in contact with ether in a small
Erlenmeyer flask for twenty-four hours—leaving it overnight is better—
and decanting, and again allowing the substance to remain in contact with a
little fresh ether for an hour, and finally filtering through a weighed filter,
of nitro-glycerine and 25 per cent. of the infusorial earth kieselguhr. The
analysis is very simple, and may be conducted as follows:—Weigh out
about 10 grms. of the substance, and place over calcium chloride in a
desiccator for some six to eight days, and then re-weigh. The loss of weight
gives the moisture. This will generally be very small, probably never more
than 1 per cent., and usually less.
Mr James O. Handy, in order to save time, proposes to dry dynamite in
the following manner. He places 1 grm. of the material in a porcelain
crucible 1 inch in diameter. The crucible is then supported at the bottom of
an extra wide-mouthed bottle of about 600 c.c. capacity. Air, which has
been dried by bubbling through strong sulphuric acid, is now drawn over
the surface of the sample for three hours by means of an ordinary aspirator.
The air should pass approximately at the rate of 10 c.c. per second. The tube
by which the dry air enters the bottle extends to within 1 inch of the
crucible containing the dynamite. An empty safety bottle is connected with
the inlet, and another with the outlet of the wide-mouthed bottle. The first
guards against the mechanical carrying over by the air current of sulphuric
acid from the acid bottle into the sample, whilst the second prevents
spasmodic outbursts of water from the exhaust from reaching the sample.
The method also gave satisfactory results with nitro-glycerine. The dry
substance may now be wrapped in filter paper, the whole weighed, and the
nitro-glycerine extracted in the Soxhlet apparatus with ether. The ether
should be distilled over at least twenty-four times.
I have found, however, that much quicker, and quite as accurate, results
may be obtained by leaving the dynamite in contact with ether in a small
Erlenmeyer flask for twenty-four hours—leaving it overnight is better—
and decanting, and again allowing the substance to remain in contact with a
little fresh ether for an hour, and finally filtering through a weighed filter,
Page 212
drying at 100° C., and weighing. This gives the weight of the kieselguhr.
The nitro-glycerine must be obtained by difference, as it is quite useless to
evaporate down the ethereal solution to obtain it, as it is itself volatile to a
very considerable extent at the temperature of evaporation of the ether, and
the result, therefore, will always be much too low. The dry guhr can, of
course, be examined, either qualitatively or quantitatively, for other mineral
salts, such as carbonate of soda, &c. An actual analysis of dynamite No. 1
made by the author at Hayle gave— Moisture, 0.92 per cent.; kieselguhr,
26.15 per cent.; and nitro- glycerine, 72.93 per cent., the last being obtained
by difference.
~Nitro-Glycerine.~—It is sometimes desired to test an explosive
substance for nitro-glycerine. If an oily liquid is oozing from the substance,
soak a drop of it in filter paper. If it is nitro-glycerine it will make a greasy
spot. If the paper is now placed upon an iron anvil, and struck with an iron
hammer, it will explode with a sharp report, if lighted it burns with a
yellowish to greenish flame, emitting a crackling sound, and placed upon an
iron plate and heated from beneath, it explodes sharply.
If a few drops of nitro-glycerine are placed in a test tube, and shaken up
with methyl-alcohol (previously tested with distilled water, to see that it
produces no turbidity), and filtered, on the addition of distilled water, the
solution will become milky, and the nitro-glycerine will separate out, and
finally collect at the bottom of the tube.
If to a solution of a trace of nitro-glycerine in methyl-alcohol, a few
drops of a solution, composed of 1 volume of aniline, and 40 volumes
sulphuric acid (1.84) be added, a deep purple colour will be produced. This
colour changes to green upon the addition of water. If it is necessary to
determine the nitro-glycerine quantitatively in an explosive, the scheme on
The nitro-glycerine must be obtained by difference, as it is quite useless to
evaporate down the ethereal solution to obtain it, as it is itself volatile to a
very considerable extent at the temperature of evaporation of the ether, and
the result, therefore, will always be much too low. The dry guhr can, of
course, be examined, either qualitatively or quantitatively, for other mineral
salts, such as carbonate of soda, &c. An actual analysis of dynamite No. 1
made by the author at Hayle gave— Moisture, 0.92 per cent.; kieselguhr,
26.15 per cent.; and nitro- glycerine, 72.93 per cent., the last being obtained
by difference.
~Nitro-Glycerine.~—It is sometimes desired to test an explosive
substance for nitro-glycerine. If an oily liquid is oozing from the substance,
soak a drop of it in filter paper. If it is nitro-glycerine it will make a greasy
spot. If the paper is now placed upon an iron anvil, and struck with an iron
hammer, it will explode with a sharp report, if lighted it burns with a
yellowish to greenish flame, emitting a crackling sound, and placed upon an
iron plate and heated from beneath, it explodes sharply.
If a few drops of nitro-glycerine are placed in a test tube, and shaken up
with methyl-alcohol (previously tested with distilled water, to see that it
produces no turbidity), and filtered, on the addition of distilled water, the
solution will become milky, and the nitro-glycerine will separate out, and
finally collect at the bottom of the tube.
If to a solution of a trace of nitro-glycerine in methyl-alcohol, a few
drops of a solution, composed of 1 volume of aniline, and 40 volumes
sulphuric acid (1.84) be added, a deep purple colour will be produced. This
colour changes to green upon the addition of water. If it is necessary to
determine the nitro-glycerine quantitatively in an explosive, the scheme on
Page 213
page 213 may be followed. Ether is the best solvent to use. Nitrogen should
be determined in the nitrometer.
~Gelatine Compounds.~—The simplest of these compounds is, of
course, blasting gelatine, as it consists of nothing but nitro-cotton and nitro-
glycerine, the nitro-cellulose being dissolved in the glycerine to form a
clear jelly, the usual proportions being about 92 per cent. of nitro- glycerine
to 8 per cent. nitro-cotton, but the cotton is found as high as 10 per cent. in
some gelatines. Gelatine dynamite and gelignite are blasting gelatines, with
varying proportions of wood-pulp and saltpetre (KNO_{3}) mixed with a
thin blasting gelatine. The method of analysis is as follows:—Weigh out 10
grms. of the substance, previously cut up into small pieces with a platinum
spatula, and place over calcium chloride in a desiccator for some days.
Reweigh. The loss equals moisture. This is generally very small. Or
Handy's method may be used. The dried sample is then transferred to a
small thistle-headed funnel which has been cut off from its stem, and the
opening plugged with a little glass wool, and round the top rim of which a
piece of fine platinum wire has been fastened, in order that it may
afterwards be easily removed from the Soxhlet tube. The weight of this
funnel and the glass wool must be accurately known. It is then transferred
to the Soxhlet tube and exhausted with ether, which dissolves out the nitro-
glycerine. The weighed residue must afterwards be treated in a flask with
ether-alcohol to dissolve out the nitro-cotton.
But the more expeditious method, and one quite as accurate, is to transfer
the dried gelatine to a conical Erlenmeyer flask of about 500 c.c. capacity,
and add 250 c.c. of a mixture of ether-alcohol (2 ether to 1 alcohol), and
allow to stand overnight. Sometimes a further addition of ether-alcohol is
necessary. It is always better to add another 300 c.c., and leave for twenty
minutes or so after the solution has been filtered off. The undissolved
be determined in the nitrometer.
~Gelatine Compounds.~—The simplest of these compounds is, of
course, blasting gelatine, as it consists of nothing but nitro-cotton and nitro-
glycerine, the nitro-cellulose being dissolved in the glycerine to form a
clear jelly, the usual proportions being about 92 per cent. of nitro- glycerine
to 8 per cent. nitro-cotton, but the cotton is found as high as 10 per cent. in
some gelatines. Gelatine dynamite and gelignite are blasting gelatines, with
varying proportions of wood-pulp and saltpetre (KNO_{3}) mixed with a
thin blasting gelatine. The method of analysis is as follows:—Weigh out 10
grms. of the substance, previously cut up into small pieces with a platinum
spatula, and place over calcium chloride in a desiccator for some days.
Reweigh. The loss equals moisture. This is generally very small. Or
Handy's method may be used. The dried sample is then transferred to a
small thistle-headed funnel which has been cut off from its stem, and the
opening plugged with a little glass wool, and round the top rim of which a
piece of fine platinum wire has been fastened, in order that it may
afterwards be easily removed from the Soxhlet tube. The weight of this
funnel and the glass wool must be accurately known. It is then transferred
to the Soxhlet tube and exhausted with ether, which dissolves out the nitro-
glycerine. The weighed residue must afterwards be treated in a flask with
ether-alcohol to dissolve out the nitro-cotton.
But the more expeditious method, and one quite as accurate, is to transfer
the dried gelatine to a conical Erlenmeyer flask of about 500 c.c. capacity,
and add 250 c.c. of a mixture of ether-alcohol (2 ether to 1 alcohol), and
allow to stand overnight. Sometimes a further addition of ether-alcohol is
necessary. It is always better to add another 300 c.c., and leave for twenty
minutes or so after the solution has been filtered off. The undissolved
Page 214
portion, which consists of wood-pulp, potassium nitrate, and other salts, is
filtered off through a linen or paper filter, dried and weighed.
~Solution.~—The ether-alcohol solution contains the nitro-cotton and the
nitro-glycerine in solution.[A] To this solution add excess of chloroform
(about 100 c.c. will be required), when the nitro-cellulose will be
precipitated in a gelatinous form. This should be filtered off through a linen
filter, and allowed to drain. It is useless to attempt to use a filter pump, as it
generally causes it to set solid. The precipitated cotton should then be
redissolved in ether-alcohol, and again precipitated with chloroform (20 c.c.
of ether-alcohol should be used). This precaution is absolutely necessary, if
the substance has been treated with ether- alcohol at first instead of ether
only, otherwise the results will be much too high, owing to the gelatinous
precipitate retaining very considerable quantities of nitro-glycerine. The
precipitate is then allowed to drain as completely as possible, and finally
allowed to dry in the air bath at 40° C., until it is easily detached from the
linen filter by the aid of a spatula, and is then transferred to a weighed
watch-glass, replaced in the oven, and dried at 40° C. until constant in
weight. The weight found, calculated upon the 10 grms. taken, gives the
percentage of nitro- cellulose.
[Footnote A: If the substance has been treated with ether alone in the
Soxhlet, the nitro-glycerine will of course be dissolved out first, and the
ether-alcohol solution will only contain the nitro-cellulose.]
~The Residue~ left after treating the gelatine with ether-alcohol is, in the
case of blasting gelatine, very small, and will probably consist of nothing
but carbonate of soda. It should be dried at 100° C. and weighed, but in the
case of either gelignite or gelatine dynamite this residue should be
transferred to a beaker and boiled with distilled water, and the water
decanted some eight or ten times, and the residue finally transferred to a
filtered off through a linen or paper filter, dried and weighed.
~Solution.~—The ether-alcohol solution contains the nitro-cotton and the
nitro-glycerine in solution.[A] To this solution add excess of chloroform
(about 100 c.c. will be required), when the nitro-cellulose will be
precipitated in a gelatinous form. This should be filtered off through a linen
filter, and allowed to drain. It is useless to attempt to use a filter pump, as it
generally causes it to set solid. The precipitated cotton should then be
redissolved in ether-alcohol, and again precipitated with chloroform (20 c.c.
of ether-alcohol should be used). This precaution is absolutely necessary, if
the substance has been treated with ether- alcohol at first instead of ether
only, otherwise the results will be much too high, owing to the gelatinous
precipitate retaining very considerable quantities of nitro-glycerine. The
precipitate is then allowed to drain as completely as possible, and finally
allowed to dry in the air bath at 40° C., until it is easily detached from the
linen filter by the aid of a spatula, and is then transferred to a weighed
watch-glass, replaced in the oven, and dried at 40° C. until constant in
weight. The weight found, calculated upon the 10 grms. taken, gives the
percentage of nitro- cellulose.
[Footnote A: If the substance has been treated with ether alone in the
Soxhlet, the nitro-glycerine will of course be dissolved out first, and the
ether-alcohol solution will only contain the nitro-cellulose.]
~The Residue~ left after treating the gelatine with ether-alcohol is, in the
case of blasting gelatine, very small, and will probably consist of nothing
but carbonate of soda. It should be dried at 100° C. and weighed, but in the
case of either gelignite or gelatine dynamite this residue should be
transferred to a beaker and boiled with distilled water, and the water
decanted some eight or ten times, and the residue finally transferred to a
Page 215
tarred filter and washed for some time with hot water. The residue left upon
the filter is wood-pulp. This is dried at 100° C. until constant, and weighed.
The solution and washings from the wood are evaporated down in a
platinum dish, and dried at 100° C. It will consist of the potassium nitrate,
and any other mineral salts, such as carbonate of soda, which should always
be tested for by adding a few drops of nitric acid and a little water to the
residue, and again evaporating to dryness and re-weighing. From the
difference in weight the soda can be calculated, sodium nitrate having been
formed. Thus—
Na_{2}CO_{3} + 2HNO_{3} = 2NaNO_{3} + CO_{2} + H_{2}O.
Mol. wt. = 106 = 170
(170 - 106 = 64) and x = (106 x d)/64
where x equals grms. of sodium carbonate in residue, and d equals the
difference in weight of residue, before and after treatment with nitric acid.
The nitro-glycerine is best found by difference, but if desired the
solutions from the precipitation of the nitro-cellulose may be evaporated
down upon the water bath at 30° to 40° C., and finally dried over CaCl_{2}
until no smell of ether or chloroform can be detected, and the nitro-
glycerine weighed. It will, however, always be much too low. An actual
analysis of a sample of gelatine dynamite gave the following result:—
Nitrocellulose (collodion) 3.819 per cent.
Nitro-glycerine 66.691 "
Wood-pulp 16.290 "
KNO_{3} 12.890 "
Na_{2}CO_{3} Nil.
Water 0.340 "
the filter is wood-pulp. This is dried at 100° C. until constant, and weighed.
The solution and washings from the wood are evaporated down in a
platinum dish, and dried at 100° C. It will consist of the potassium nitrate,
and any other mineral salts, such as carbonate of soda, which should always
be tested for by adding a few drops of nitric acid and a little water to the
residue, and again evaporating to dryness and re-weighing. From the
difference in weight the soda can be calculated, sodium nitrate having been
formed. Thus—
Na_{2}CO_{3} + 2HNO_{3} = 2NaNO_{3} + CO_{2} + H_{2}O.
Mol. wt. = 106 = 170
(170 - 106 = 64) and x = (106 x d)/64
where x equals grms. of sodium carbonate in residue, and d equals the
difference in weight of residue, before and after treatment with nitric acid.
The nitro-glycerine is best found by difference, but if desired the
solutions from the precipitation of the nitro-cellulose may be evaporated
down upon the water bath at 30° to 40° C., and finally dried over CaCl_{2}
until no smell of ether or chloroform can be detected, and the nitro-
glycerine weighed. It will, however, always be much too low. An actual
analysis of a sample of gelatine dynamite gave the following result:—
Nitrocellulose (collodion) 3.819 per cent.
Nitro-glycerine 66.691 "
Wood-pulp 16.290 "
KNO_{3} 12.890 "
Na_{2}CO_{3} Nil.
Water 0.340 "
Page 216
This sample was probably intended to contain 30 per cent. of absorbing
material to 70 per cent. of explosive substances. Many dynamites contain
other substances than the above, such as paraffin, resin, sulphur, wood,
coal-dust, charcoal, also mineral salts, such as carbonate of magnesia,
chlorate of potash, &c. In these cases the above-described methods must of
course be considerably modified. Paraffin, resin, and most of the sulphur
will be found in the ether solution if present. The solution should be
evaporated (and in this case the explosive should in the first case be treated
with ether only, and not ether-alcohol), and the residue weighed, and then
treated on the water bath with a solution of caustic soda. The resin goes into
solution, and is separated by decantation from the residue, and precipitated
by hydrochloric acid, and collected on a tarred filter (dried at 100° C.), and
dried at 100° C. and weighed. The nitro- glycerine residue is treated with
strong alcohol, decanted, and the residue of paraffin and sulphur washed
with alcohol, dried, and weighed.
To separate the paraffin from the sulphur the residue is heated with a
solution of ammonium sulphide. After cooling the paraffin collects as a
crust upon the surface of the liquid, and by pricking a small hole through it
with a glass rod the liquid underneath can be poured off, and the paraffin
then washed with water, dried, and weighed. Sulphur is found by difference.
Mr F.W. Smith (Jour. Amer. Chem. Soc., 1901, 23 [8], 585-589) determines
the sulphur in dynamite gelatine as follows:—About 2 grms. are warmed in
a 100 c.c. silver crucible on the water bath with an alcoholic solution of
sodium hydroxide, and where the nitro-glycerine is decomposed, the liquid
is evaporated to dryness. The residue is fused with 40 grms. of KOH and 5
grms. of potassium nitrate, the mass dissolved in dilute acetic acid and
filtered, and the sulphates precipitated in the usual way. If camphor is
present, it can be extracted with bisulphide of carbon after the material has
been treated with ether-alcohol. In that case the sulphur, paraffin, and resin
will also be dissolved. The camphor being easily volatile, can be separated
material to 70 per cent. of explosive substances. Many dynamites contain
other substances than the above, such as paraffin, resin, sulphur, wood,
coal-dust, charcoal, also mineral salts, such as carbonate of magnesia,
chlorate of potash, &c. In these cases the above-described methods must of
course be considerably modified. Paraffin, resin, and most of the sulphur
will be found in the ether solution if present. The solution should be
evaporated (and in this case the explosive should in the first case be treated
with ether only, and not ether-alcohol), and the residue weighed, and then
treated on the water bath with a solution of caustic soda. The resin goes into
solution, and is separated by decantation from the residue, and precipitated
by hydrochloric acid, and collected on a tarred filter (dried at 100° C.), and
dried at 100° C. and weighed. The nitro- glycerine residue is treated with
strong alcohol, decanted, and the residue of paraffin and sulphur washed
with alcohol, dried, and weighed.
To separate the paraffin from the sulphur the residue is heated with a
solution of ammonium sulphide. After cooling the paraffin collects as a
crust upon the surface of the liquid, and by pricking a small hole through it
with a glass rod the liquid underneath can be poured off, and the paraffin
then washed with water, dried, and weighed. Sulphur is found by difference.
Mr F.W. Smith (Jour. Amer. Chem. Soc., 1901, 23 [8], 585-589) determines
the sulphur in dynamite gelatine as follows:—About 2 grms. are warmed in
a 100 c.c. silver crucible on the water bath with an alcoholic solution of
sodium hydroxide, and where the nitro-glycerine is decomposed, the liquid
is evaporated to dryness. The residue is fused with 40 grms. of KOH and 5
grms. of potassium nitrate, the mass dissolved in dilute acetic acid and
filtered, and the sulphates precipitated in the usual way. If camphor is
present, it can be extracted with bisulphide of carbon after the material has
been treated with ether-alcohol. In that case the sulphur, paraffin, and resin
will also be dissolved. The camphor being easily volatile, can be separated
Page 217
by evaporation. Let the weight of the extract, freed from ether-alcohol
before treatment with bisulphide of carbon, equal A, and the weight of
extract after treatment with CS_{2} and evaporation of the same equal B;
and weight of the residue which is left after evaporation of the CS_{2} and
the camphor in solution equal C, the percentage of camphor will be A - B -
C. The residue C may contain traces of nitro-glycerine, resin, or sulphur.
Camphor may be separated from nitro-glycerine by means of CS_{2}. If
the solution of camphor in nitro-glycerine be shaken with CS_{2}, the
camphor and a little of the nitro-glycerine will dissolve. The bisulphide
solution is decanted, or poured into a separating funnel and separated from
the nitro-glycerine. The two solutions are then heated on the water bath to
20° C. and then to 60° C., and afterwards in a vacuum over CaCl_{2} until
the CS_{2} has evaporated from them. The camphor evaporates, and leaves
the small quantity of nitro-glycerine which had been dissolved with it. The
other portion is the nitro-glycerine, now free from CS_{2}. The two are
weighed and their weights added together, and equals the nitro- glycerine
present. There is a loss of nitro-glycerine, it being partly evaporated along
with the CS_{2}. Captain Hess has shown that it is equal to about 1.25 per
cent. This quantity should therefore be added to that found by analysis.
Morton Liebschutz, in a paper in the Moniteur Scientifique for January
1893, very rightly observes that the variety of dynamites manufactured is
very great, all of them having a special composition which, good or bad, is
sometimes of so complicated a nature that the determination of their
elements is difficult.
The determination of nitro-glycerine in simple dynamite No. 1 is easy;
but not so when the dynamite contains substances soluble in ether, such as
sulphur, resin, paraffin, and naphthalene. After detailing at length the
methods he employs, he concludes with the observation that the knowledge
of the use of acetic acid—in which nitro-glycerine dissolves—for the
before treatment with bisulphide of carbon, equal A, and the weight of
extract after treatment with CS_{2} and evaporation of the same equal B;
and weight of the residue which is left after evaporation of the CS_{2} and
the camphor in solution equal C, the percentage of camphor will be A - B -
C. The residue C may contain traces of nitro-glycerine, resin, or sulphur.
Camphor may be separated from nitro-glycerine by means of CS_{2}. If
the solution of camphor in nitro-glycerine be shaken with CS_{2}, the
camphor and a little of the nitro-glycerine will dissolve. The bisulphide
solution is decanted, or poured into a separating funnel and separated from
the nitro-glycerine. The two solutions are then heated on the water bath to
20° C. and then to 60° C., and afterwards in a vacuum over CaCl_{2} until
the CS_{2} has evaporated from them. The camphor evaporates, and leaves
the small quantity of nitro-glycerine which had been dissolved with it. The
other portion is the nitro-glycerine, now free from CS_{2}. The two are
weighed and their weights added together, and equals the nitro- glycerine
present. There is a loss of nitro-glycerine, it being partly evaporated along
with the CS_{2}. Captain Hess has shown that it is equal to about 1.25 per
cent. This quantity should therefore be added to that found by analysis.
Morton Liebschutz, in a paper in the Moniteur Scientifique for January
1893, very rightly observes that the variety of dynamites manufactured is
very great, all of them having a special composition which, good or bad, is
sometimes of so complicated a nature that the determination of their
elements is difficult.
The determination of nitro-glycerine in simple dynamite No. 1 is easy;
but not so when the dynamite contains substances soluble in ether, such as
sulphur, resin, paraffin, and naphthalene. After detailing at length the
methods he employs, he concludes with the observation that the knowledge
of the use of acetic acid—in which nitro-glycerine dissolves—for the
Page 218
determination of nitro-glycerine may be serviceable. Mr F.W. Smith[A]
gives the following indirect method of determining nitro-glycerine in
gelatine dynamite, &c. About 15 grms. of the sample are extracted with
chloroform in a Soxhlet apparatus, and the loss in weight determined. In a
second portion the moisture is determined. A third portion of about 2 grms.
is macerated with ether in a small beaker, the ethereal extract filtered, and
the process of extraction repeated three or four times. The united filtrates
are allowed to evaporate spontaneously, and the residue warmed gently on
the water bath with 5 c.c. of ammonium sulphide solution, and 10 c.c. of
alcohol until the nitro-glycerine is decomposed, after which about 250 c.c.
of water and sufficient hydrochloric acid to render the liquid strongly acid,
are added, and the liquid filtered. The precipitate is washed free from acid,
and then washed through the filter with strong alcohol and chloroform into
a weighed platinum dish, which is dried to constant weight at 50° C. The
contents of the dish are now transferred to a silver crucible, and the sulphur
determined. This amount of sulphur, deducted from the weight of the
contents of the platinum dish, gives the quantity of substances soluble in
chloroform with the exception of the nitro-glycerine, moisture, and sulphur.
The amount of the former substances plus the moisture and sulphur,
deducted from the total loss on extraction with chloroform, gives the
quantity of nitro-glycerine. Nitro-benzene may be detected, according to J.
Marpurgo, in the following manner:—In a porcelain basin are placed two
drops of liquid phenol, three drops of water, and a fragment of potash as
large as a pea. The mixture is boiled, and the aqueous solution to be tested
then added. On prolonged boiling nitro-benzene produces at the edge of the
liquid a crimson ring, which on the addition of a solution of bleaching
powder turns emerald- green. And nitro-glycerine in ether solution, by
placing a few drops of the suspected solution, together with a drop or two of
aniline, upon a watch-glass, evaporating off the ether, and then adding a
drop of concentrated sulphuric acid to the residue, when, if nitro-glycerine
gives the following indirect method of determining nitro-glycerine in
gelatine dynamite, &c. About 15 grms. of the sample are extracted with
chloroform in a Soxhlet apparatus, and the loss in weight determined. In a
second portion the moisture is determined. A third portion of about 2 grms.
is macerated with ether in a small beaker, the ethereal extract filtered, and
the process of extraction repeated three or four times. The united filtrates
are allowed to evaporate spontaneously, and the residue warmed gently on
the water bath with 5 c.c. of ammonium sulphide solution, and 10 c.c. of
alcohol until the nitro-glycerine is decomposed, after which about 250 c.c.
of water and sufficient hydrochloric acid to render the liquid strongly acid,
are added, and the liquid filtered. The precipitate is washed free from acid,
and then washed through the filter with strong alcohol and chloroform into
a weighed platinum dish, which is dried to constant weight at 50° C. The
contents of the dish are now transferred to a silver crucible, and the sulphur
determined. This amount of sulphur, deducted from the weight of the
contents of the platinum dish, gives the quantity of substances soluble in
chloroform with the exception of the nitro-glycerine, moisture, and sulphur.
The amount of the former substances plus the moisture and sulphur,
deducted from the total loss on extraction with chloroform, gives the
quantity of nitro-glycerine. Nitro-benzene may be detected, according to J.
Marpurgo, in the following manner:—In a porcelain basin are placed two
drops of liquid phenol, three drops of water, and a fragment of potash as
large as a pea. The mixture is boiled, and the aqueous solution to be tested
then added. On prolonged boiling nitro-benzene produces at the edge of the
liquid a crimson ring, which on the addition of a solution of bleaching
powder turns emerald- green. And nitro-glycerine in ether solution, by
placing a few drops of the suspected solution, together with a drop or two of
aniline, upon a watch-glass, evaporating off the ether, and then adding a
drop of concentrated sulphuric acid to the residue, when, if nitro-glycerine
Page 219
is present, the H_{2}SO_{4} will strike a crimson colour, due to the action
of the aniline sulphate upon the nitric acid liberated from the nitro-
glycerine.
[Footnote A: "Notes on the Analysis of Explosives," Jour. Amer. Chem.
Soc., 1901, 23 [8], 585-589.]
~Tonite.~—The analysis of this explosive is a comparatively easy matter,
and can be performed as follows:—Weigh out 10 grms., or a smaller
quantity, and boil with water in a beaker, decanting the liquid four or five
times, and filter. The aqueous solution will contain the nitrate of barium.
Then put the residue on the filter, and wash two or three times with boiling
water. Evaporate the filtrate to dryness in a platinum dish. Dry and weigh.
This equals the Ba(NO_{3})_{2}. If the sample is tonite No. 3, and
contains di-nitro-benzol, treat first with ether to dissolve out this substance.
Filter into a dish, and evaporate off the ether, and weigh the di-nitro-benzol,
and afterwards treat residue with water as before. The residue is dried and
weighed, and equals the gun-cotton present. It should then be treated with a
solution of ether-alcohol in a conical flask, allowed to stand some three
hours, then filtered through a weighed filter paper, dried at 40° C., and
weighed. This will give the gun-cotton, and the difference between this last
weight and the previous one will give the collodion-cotton. A portion of the
residue containing both the gun- cotton and the soluble cotton can be tested
in the nitrometer, and the nitrogen determined.
~Cordite.~—This explosive consists of gun-cotton (with a little
collodion-cotton in it as impurity), nitro-glycerine, and vaseline—the
proportions being given as 30 per cent. nitro-glycerine, 65 per cent. gun-
cotton, and 5 per cent. vaseline. Its analysis is performed by a modification
of the method given for gelatines. Five grms. may be dissolved in ether-
alcohol in a conical flask, allowed to stand all night, and then filtered
of the aniline sulphate upon the nitric acid liberated from the nitro-
glycerine.
[Footnote A: "Notes on the Analysis of Explosives," Jour. Amer. Chem.
Soc., 1901, 23 [8], 585-589.]
~Tonite.~—The analysis of this explosive is a comparatively easy matter,
and can be performed as follows:—Weigh out 10 grms., or a smaller
quantity, and boil with water in a beaker, decanting the liquid four or five
times, and filter. The aqueous solution will contain the nitrate of barium.
Then put the residue on the filter, and wash two or three times with boiling
water. Evaporate the filtrate to dryness in a platinum dish. Dry and weigh.
This equals the Ba(NO_{3})_{2}. If the sample is tonite No. 3, and
contains di-nitro-benzol, treat first with ether to dissolve out this substance.
Filter into a dish, and evaporate off the ether, and weigh the di-nitro-benzol,
and afterwards treat residue with water as before. The residue is dried and
weighed, and equals the gun-cotton present. It should then be treated with a
solution of ether-alcohol in a conical flask, allowed to stand some three
hours, then filtered through a weighed filter paper, dried at 40° C., and
weighed. This will give the gun-cotton, and the difference between this last
weight and the previous one will give the collodion-cotton. A portion of the
residue containing both the gun- cotton and the soluble cotton can be tested
in the nitrometer, and the nitrogen determined.
~Cordite.~—This explosive consists of gun-cotton (with a little
collodion-cotton in it as impurity), nitro-glycerine, and vaseline—the
proportions being given as 30 per cent. nitro-glycerine, 65 per cent. gun-
cotton, and 5 per cent. vaseline. Its analysis is performed by a modification
of the method given for gelatines. Five grms. may be dissolved in ether-
alcohol in a conical flask, allowed to stand all night, and then filtered
Page 220
through a linen filter. The residue is washed with a little ether, pressed, and
dried at 40° C., and weighed. It equals the gun-cotton. The solution contains
the nitro-glycerine, soluble cotton, and vaseline. The cotton is precipitated
with chloroform, filtered off, dried, and weighed. The two ether-alcohol
solutions are mixed, and carefully evaporated down in a platinum dish upon
the water bath at a low temperature. The residue is afterwards treated with
strong 80 per cent. acetic acid, which dissolves out any nitro-glycerine left
in it. The nitro-glycerine is then obtained by difference, or the method
suggested to me privately by Mr W.J. Williams may be used. The residue
obtained by evaporation of the ether-alcohol solution, after weighing, is
treated with alcoholic potash to decompose the nitro-glycerine, water is
added and the alcohol evaporated off. Some ether is then added, and the
mixture shaken, and the ether separated and evaporated, and the residue
weighed as vaseline.
The moisture should, however, be determined by the method devised by
Mr Arthur Marshall, F.I.C., of the Royal Gunpowder Works, Waltham
Abbey, which is carried out as follows:—The cordite or other explosive is
prepared in the manner laid down for the Abel heat test, that is t say, it is
ground in a small mill, and that portion is selected which passes through a
sieve having holes of the size of No. 8 wire gauge, but not through one with
holes No. 14 wire gauge.
[Illustration: FIG. 40.—MARSHALL'S APPARATUS FOR MOISTURE
IN CORDITE.]
The form of apparatus used is shown in Fig. 40. It consists of an
aluminium dish A, having the dimensions shown, and the glass cone B
weighing not more than 30 grms. Five grms. of the cordite are weighed into
the aluminium dish A. This is covered with the cone B, and the whole is
accurately weighed, and is then placed upon a metal plate heated by steam
dried at 40° C., and weighed. It equals the gun-cotton. The solution contains
the nitro-glycerine, soluble cotton, and vaseline. The cotton is precipitated
with chloroform, filtered off, dried, and weighed. The two ether-alcohol
solutions are mixed, and carefully evaporated down in a platinum dish upon
the water bath at a low temperature. The residue is afterwards treated with
strong 80 per cent. acetic acid, which dissolves out any nitro-glycerine left
in it. The nitro-glycerine is then obtained by difference, or the method
suggested to me privately by Mr W.J. Williams may be used. The residue
obtained by evaporation of the ether-alcohol solution, after weighing, is
treated with alcoholic potash to decompose the nitro-glycerine, water is
added and the alcohol evaporated off. Some ether is then added, and the
mixture shaken, and the ether separated and evaporated, and the residue
weighed as vaseline.
The moisture should, however, be determined by the method devised by
Mr Arthur Marshall, F.I.C., of the Royal Gunpowder Works, Waltham
Abbey, which is carried out as follows:—The cordite or other explosive is
prepared in the manner laid down for the Abel heat test, that is t say, it is
ground in a small mill, and that portion is selected which passes through a
sieve having holes of the size of No. 8 wire gauge, but not through one with
holes No. 14 wire gauge.
[Illustration: FIG. 40.—MARSHALL'S APPARATUS FOR MOISTURE
IN CORDITE.]
The form of apparatus used is shown in Fig. 40. It consists of an
aluminium dish A, having the dimensions shown, and the glass cone B
weighing not more than 30 grms. Five grms. of the cordite are weighed into
the aluminium dish A. This is covered with the cone B, and the whole is
accurately weighed, and is then placed upon a metal plate heated by steam
Page 221
from a water bath. It is left upon the bath until all the moisture has been
driven off, then it is allowed to cool for about half-an-hour in a desiccator
and is weighed. The loss in weight gives accurately the moisture of the
sample. For cordite of the original composition, one hour's heating is
sufficient to entirely drive off the moisture; for modified cordite containing
65 per cent. of gun-cotton, two hours is enough, provided that there be not
more than 1.3 per cent. of moisture present.
If the proportion of nitro-glycerine be higher, a longer heating is
necessary. The aluminium dish must not be shallower than shown in the
figure, for if the distance between the substance and the edge of the glass
cone be less than half an inch, some nitro-glycerine will be lost. Again, the
sample must not be ground finer than stated, else some of the moisture will
be lost in the grinding and sieving operations, and the result will be too low.
In order to be able to drive off all the moisture in the times mentioned, it is
essential that the glass cone shall not fit too closely on the aluminium dish,
consequently the horizontal ledge round the top of the dish should be bent,
so as to render it slightly untrue, and leave a clearance of about 0.02 inch in
some places. If these few simple precautions be taken, the method will be
found to be very accurate. Duplicate determinations do not differ more than
0.01 per cent.[A]
[Footnote A: "Determination of Moisture in Nitro-glycerine Explosives,"
by
A. Marshall, Jour. Soc. Chem. Ind., Feb. 29, 1904, p. 154.]
~The Vaseline~ (C_{16}H_{34}), or petroleum jelly, used has a flash-
point of 400° F. It must not contain more than 0.2 per cent. volatile matter
when heated for 12 hours on the water bath, and should have a specific
gravity of 0.87 at 100° F., and a melting point of 86° F. It is obtained during
driven off, then it is allowed to cool for about half-an-hour in a desiccator
and is weighed. The loss in weight gives accurately the moisture of the
sample. For cordite of the original composition, one hour's heating is
sufficient to entirely drive off the moisture; for modified cordite containing
65 per cent. of gun-cotton, two hours is enough, provided that there be not
more than 1.3 per cent. of moisture present.
If the proportion of nitro-glycerine be higher, a longer heating is
necessary. The aluminium dish must not be shallower than shown in the
figure, for if the distance between the substance and the edge of the glass
cone be less than half an inch, some nitro-glycerine will be lost. Again, the
sample must not be ground finer than stated, else some of the moisture will
be lost in the grinding and sieving operations, and the result will be too low.
In order to be able to drive off all the moisture in the times mentioned, it is
essential that the glass cone shall not fit too closely on the aluminium dish,
consequently the horizontal ledge round the top of the dish should be bent,
so as to render it slightly untrue, and leave a clearance of about 0.02 inch in
some places. If these few simple precautions be taken, the method will be
found to be very accurate. Duplicate determinations do not differ more than
0.01 per cent.[A]
[Footnote A: "Determination of Moisture in Nitro-glycerine Explosives,"
by
A. Marshall, Jour. Soc. Chem. Ind., Feb. 29, 1904, p. 154.]
~The Vaseline~ (C_{16}H_{34}), or petroleum jelly, used has a flash-
point of 400° F. It must not contain more than 0.2 per cent. volatile matter
when heated for 12 hours on the water bath, and should have a specific
gravity of 0.87 at 100° F., and a melting point of 86° F. It is obtained during
Page 222
the distillation of petroleum, and consists mainly of the portions distilling
above 200° C. It boils at about 278° C.
~Acetone~ (CH_{3}CO.CH_{3}), or dimethyl ketone, is formed when
iso-propyl alcohol is oxidised with potassium bichromate and sulphuric. It
is also produced in considerable quantities during the dry distillation of
wood, and many other organic compounds. Crude wood spirit, which has
been freed from acetic acid, consists in the main of a mixture of acetone and
methyl- alcohol. The two substances may be roughly separated by the
addition of calcium chloride, which combines with the methyl-alcohol. On
subsequent distillation crude acetone passes over, and may be purified by
conversion into the bisulphite compound.
Acetone is usually prepared, however, by the dry distillation of crude
calcium or barium acetate.
(CH_{3}.COO){2}Ca = CH{3}.CO.CH_{3} + CaCO_{3}.
The distillate is fractionated, and the portion, boiling between 50° and
60° C., mixed with strong solution of sodium bisulphite. The crystalline
cake of acetone sodium bisulphite, which separates on standing, is well
pressed, to free it from impurities, decomposed by distillation with dilute
sodium carbonate, and the aqueous distillate of pure acetone dehydrated
over calcium chloride. Acetone is a colourless, mobile liquid of sp. gr. .792
at 20° C., it boils at 56.5° C., has a peculiar, pleasant, ethereal odour, and is
mixible with water, alcohol, and ether in all proportions.
The acetone used in the manufacture of cordite should conform to the
following specification:—
SPECIFICATION FOR ACETONE.
above 200° C. It boils at about 278° C.
~Acetone~ (CH_{3}CO.CH_{3}), or dimethyl ketone, is formed when
iso-propyl alcohol is oxidised with potassium bichromate and sulphuric. It
is also produced in considerable quantities during the dry distillation of
wood, and many other organic compounds. Crude wood spirit, which has
been freed from acetic acid, consists in the main of a mixture of acetone and
methyl- alcohol. The two substances may be roughly separated by the
addition of calcium chloride, which combines with the methyl-alcohol. On
subsequent distillation crude acetone passes over, and may be purified by
conversion into the bisulphite compound.
Acetone is usually prepared, however, by the dry distillation of crude
calcium or barium acetate.
(CH_{3}.COO){2}Ca = CH{3}.CO.CH_{3} + CaCO_{3}.
The distillate is fractionated, and the portion, boiling between 50° and
60° C., mixed with strong solution of sodium bisulphite. The crystalline
cake of acetone sodium bisulphite, which separates on standing, is well
pressed, to free it from impurities, decomposed by distillation with dilute
sodium carbonate, and the aqueous distillate of pure acetone dehydrated
over calcium chloride. Acetone is a colourless, mobile liquid of sp. gr. .792
at 20° C., it boils at 56.5° C., has a peculiar, pleasant, ethereal odour, and is
mixible with water, alcohol, and ether in all proportions.
The acetone used in the manufacture of cordite should conform to the
following specification:—
SPECIFICATION FOR ACETONE.
Page 223
1. The acetone to be not more than 0.802 specific gravity at 60° F. When
mixed with distilled water it must show no turbidity, and must leave no
residue on evaporation at 212° F. On distillation, four-fifths by volume of
the quantity taken must distil over at a temperature not exceeding 138° F.
The residual matter left after this distillation must not contain, besides
acetone, any ingredient that is not a bye-product incidental to the
manufacture of acetone.
2. One c.c. of 0.10 per cent. solution in distilled water of pure
permanganate of potash, added to 100 c.c. of the acetone, must retain its
distinctive colour for not less than 30 minutes. This test should be made at a
temperature of 60° F.
3. The acetone tested by the following method must not show more than
0.005 per cent. of acid, calculated to acetic acid:—
To 50 c.c. of the sample diluted with 50 c.c. of distilled water, with 2 c.c.
of phenol-phthalein solution (1 gramme to 1,000 c.c. of 50 per cent.
alcohol) added as an indicator, add from a burette N/100 sodium hydrate
solution (1 c.c. 0.0006 gramme acetic acid), and calculate to acetic acid in
the usual manner.
The water used for the dilution of the acetone must be carefully tested for
acidity, and the pipettes used for measuring should not be blown out, as it
would be possible thus to neutralise nearly 2 c.c. of the soda solution.
The presence of water in a sample of acetone may be detected by
Schweitzer and Lungwitz's method (Chem. Zeit., 1895, xix., p. 1384),
which consists in shaking together equal volumes of acetone and petroleum
ether (boiling point, 40° to 60° C.), when if present a separation of the
liquid in layers will take place.
mixed with distilled water it must show no turbidity, and must leave no
residue on evaporation at 212° F. On distillation, four-fifths by volume of
the quantity taken must distil over at a temperature not exceeding 138° F.
The residual matter left after this distillation must not contain, besides
acetone, any ingredient that is not a bye-product incidental to the
manufacture of acetone.
2. One c.c. of 0.10 per cent. solution in distilled water of pure
permanganate of potash, added to 100 c.c. of the acetone, must retain its
distinctive colour for not less than 30 minutes. This test should be made at a
temperature of 60° F.
3. The acetone tested by the following method must not show more than
0.005 per cent. of acid, calculated to acetic acid:—
To 50 c.c. of the sample diluted with 50 c.c. of distilled water, with 2 c.c.
of phenol-phthalein solution (1 gramme to 1,000 c.c. of 50 per cent.
alcohol) added as an indicator, add from a burette N/100 sodium hydrate
solution (1 c.c. 0.0006 gramme acetic acid), and calculate to acetic acid in
the usual manner.
The water used for the dilution of the acetone must be carefully tested for
acidity, and the pipettes used for measuring should not be blown out, as it
would be possible thus to neutralise nearly 2 c.c. of the soda solution.
The presence of water in a sample of acetone may be detected by
Schweitzer and Lungwitz's method (Chem. Zeit., 1895, xix., p. 1384),
which consists in shaking together equal volumes of acetone and petroleum
ether (boiling point, 40° to 60° C.), when if present a separation of the
liquid in layers will take place.
Page 224
~Estimation of Acetone.~—Kebler (Jour. Amer. Chem. Soc., 1897, 19,
316- 320) has improved Squibb's modification of Robineau and Rollins'
method. The following solutions are required:—
(1.) A 6 per cent. solution of hydrochloric acid.
(2.) A decinormal solution of sodium thiosulphate.
(3.) Alkaline potassium iodide solution prepared by dissolving 250 grms.
of potassium iodide in water, made up to a litre; dissolving 257 grms. of
sodium hydroxide (by alcohol) in water, likewise made up to a litre. After
allowing the latter to stand, 800 c.c. of the clear solution are added to the
litre of KI.
(4.) Sodium hypochlorite solution: 100 grms. of bleaching powder (35
per cent.) are mixed with 400 c.c. of water: to this is added a hot solution of
120 grms. of crystallised sodium carbonate in 400 c.c. of water. After
cooling, the clear liquid is decanted, the remainder filtered, and the filtrate
made up to a litre; to each litre is added 25 c.c. of sodium hydroxide
solution (sp. gr. 1.29).
(5.) An aqueous solution of the acetone, containing 1 or 2 per cent. of
acetone.
(6.) Bicarbonated starch solution prepared by treating 0.125 grm. of
starch with 5 c.c. of cold water, then adding 20 c.c. of boiling water, boiling
a few minutes, cooling, and adding 2 grms. of sodium bicarbonate.
To 20 c.c. of the potassium iodide solution are added 10 c.c. of the
diluted aqueous acetone, an excess of the sodium hypochlorite solution is
then run in from a burette and well shaken for a minute. The mixture is then
acidified with the hydrochloric acid solution, and while agitated, an excess
316- 320) has improved Squibb's modification of Robineau and Rollins'
method. The following solutions are required:—
(1.) A 6 per cent. solution of hydrochloric acid.
(2.) A decinormal solution of sodium thiosulphate.
(3.) Alkaline potassium iodide solution prepared by dissolving 250 grms.
of potassium iodide in water, made up to a litre; dissolving 257 grms. of
sodium hydroxide (by alcohol) in water, likewise made up to a litre. After
allowing the latter to stand, 800 c.c. of the clear solution are added to the
litre of KI.
(4.) Sodium hypochlorite solution: 100 grms. of bleaching powder (35
per cent.) are mixed with 400 c.c. of water: to this is added a hot solution of
120 grms. of crystallised sodium carbonate in 400 c.c. of water. After
cooling, the clear liquid is decanted, the remainder filtered, and the filtrate
made up to a litre; to each litre is added 25 c.c. of sodium hydroxide
solution (sp. gr. 1.29).
(5.) An aqueous solution of the acetone, containing 1 or 2 per cent. of
acetone.
(6.) Bicarbonated starch solution prepared by treating 0.125 grm. of
starch with 5 c.c. of cold water, then adding 20 c.c. of boiling water, boiling
a few minutes, cooling, and adding 2 grms. of sodium bicarbonate.
To 20 c.c. of the potassium iodide solution are added 10 c.c. of the
diluted aqueous acetone, an excess of the sodium hypochlorite solution is
then run in from a burette and well shaken for a minute. The mixture is then
acidified with the hydrochloric acid solution, and while agitated, an excess
Page 225
of sodium thiosulphate solution is added, the mixture being afterwards
allowed to stand a few minutes. The starch indicator is then added, and the
excess of thiosulphate re-titrated. The relation of the sodium hypochlorite
solution to the sodium thiosulphate being known, the percentage of acetone
can be readily calculated.[A]
[Footnote A: See "The Testing of Acetone," Conroy, Jour. Soc. Chem.
Ind., 31st March 1900, vol. xix.]
Dr S.J.M. Auld has recently (Jour. Chem. Soc., Feb. 15, 1906, vol. xxv.)
worked out a volumetric method for the estimation of acetone, depending
on the formation of bromoform, and its subsequent hydrolysis with
alcoholic potash. The hydrolysis is probably expressed thus—
3CHBr_{3} + 9KOH + C_{2}H_{5}OH = 3CO + C_{2}H_{4} + 9KBr
+ 7H_{2}O
as it has been shown by Hermann and Long that exactly 3 volumes of
carbon monoxide to 1 of ethylene are evolved. The residual potassium
bromide is estimated by means of standard silver nitrate solution.
Bromoform is specially suitable for this purpose for several reasons. It is
very readily formed by the action of bromine and potash on acetone, and
although very volatile in steam, it is not liable to loss due to its own
evaporation. Further, its high molecular weight and large percentage of
bromine conduce to accurate results, 58 grms. of acetone being responsible
for the formation of 357 grms. of KBr. The method of carrying out the
analysis is as follows:—
A known quantity of the solution to be tested, containing acetone to the
extent of 0.1 to 0.2 grm., is pipetted into a 500 c.c. round-bottom flask,
diluted with a little water, and mixed with 20 to 30 c.c. of a 10 per cent.
solution of caustic potash. The flask is connected with a long reflex
allowed to stand a few minutes. The starch indicator is then added, and the
excess of thiosulphate re-titrated. The relation of the sodium hypochlorite
solution to the sodium thiosulphate being known, the percentage of acetone
can be readily calculated.[A]
[Footnote A: See "The Testing of Acetone," Conroy, Jour. Soc. Chem.
Ind., 31st March 1900, vol. xix.]
Dr S.J.M. Auld has recently (Jour. Chem. Soc., Feb. 15, 1906, vol. xxv.)
worked out a volumetric method for the estimation of acetone, depending
on the formation of bromoform, and its subsequent hydrolysis with
alcoholic potash. The hydrolysis is probably expressed thus—
3CHBr_{3} + 9KOH + C_{2}H_{5}OH = 3CO + C_{2}H_{4} + 9KBr
+ 7H_{2}O
as it has been shown by Hermann and Long that exactly 3 volumes of
carbon monoxide to 1 of ethylene are evolved. The residual potassium
bromide is estimated by means of standard silver nitrate solution.
Bromoform is specially suitable for this purpose for several reasons. It is
very readily formed by the action of bromine and potash on acetone, and
although very volatile in steam, it is not liable to loss due to its own
evaporation. Further, its high molecular weight and large percentage of
bromine conduce to accurate results, 58 grms. of acetone being responsible
for the formation of 357 grms. of KBr. The method of carrying out the
analysis is as follows:—
A known quantity of the solution to be tested, containing acetone to the
extent of 0.1 to 0.2 grm., is pipetted into a 500 c.c. round-bottom flask,
diluted with a little water, and mixed with 20 to 30 c.c. of a 10 per cent.
solution of caustic potash. The flask is connected with a long reflex
Page 226
condenser, and is also fitted with a dropping funnel containing a solution of
bromine in potassium bromide (200 grms. of Br and 250 grms. of KBr to 1
litre of water). The bromine solution is allowed to flow into the mixture
until it has acquired a faint yellow tinge, the flask and its contents being
then heated on the water bath at about 70° C. for half-an- hour. Bromine
solution is added drop by drop until the slight coloration is permanent,
excess of bromine being got rid of by boiling for a minute or two with a
little more caustic potash. The mixture is then distilled until the distillate is
free from bromoform, halogen being tested for in the usual manner. Water is
added to the contents of the flask if necessary. It may be here observed that
no acetone can be detected in the distillate by means of the mercuric oxide
test, and free bromine is also absent. The condenser having been washed out
with a little alcohol, in order to remove any traces of bromoform which may
have collected, the distillate and washings are mixed with 50 c.c. of alcohol
and sufficient solid caustic potash to make an approximately 10 per cent.
solution. The mixture is then heated on the water bath under a reflux
condenser until the bromoform is completely decomposed. This generally
occupies about three-quarters of an hour. The liquid is allowed to cool,
evaporated to smaller bulk if necessary, and exactly neutralised with dilute
nitric acid. It is then diluted with water to 500 c.c., and an aliquot part
titrated with N/10 silver nitrate solution, using potassium chromate as
indicator; 240 parts of bromine correspond to 58 parts of acetone. The
complete analysis can be performed in one and a half to two hours. It is
imperative that the bromine used should be pure, as crude bromine
frequently contains bromoform. The method is suitable for the estimation of
acetone in wood-spirit, the spirit being diluted to 10 times its volume, and 5
c.c. of this solution employed for the determination. For example—
(1.) Three c.c. of a solution containing 9.61 per cent. acetone gave 1.7850
grm. KBr. Acetone found = 9.66 per cent.
bromine in potassium bromide (200 grms. of Br and 250 grms. of KBr to 1
litre of water). The bromine solution is allowed to flow into the mixture
until it has acquired a faint yellow tinge, the flask and its contents being
then heated on the water bath at about 70° C. for half-an- hour. Bromine
solution is added drop by drop until the slight coloration is permanent,
excess of bromine being got rid of by boiling for a minute or two with a
little more caustic potash. The mixture is then distilled until the distillate is
free from bromoform, halogen being tested for in the usual manner. Water is
added to the contents of the flask if necessary. It may be here observed that
no acetone can be detected in the distillate by means of the mercuric oxide
test, and free bromine is also absent. The condenser having been washed out
with a little alcohol, in order to remove any traces of bromoform which may
have collected, the distillate and washings are mixed with 50 c.c. of alcohol
and sufficient solid caustic potash to make an approximately 10 per cent.
solution. The mixture is then heated on the water bath under a reflux
condenser until the bromoform is completely decomposed. This generally
occupies about three-quarters of an hour. The liquid is allowed to cool,
evaporated to smaller bulk if necessary, and exactly neutralised with dilute
nitric acid. It is then diluted with water to 500 c.c., and an aliquot part
titrated with N/10 silver nitrate solution, using potassium chromate as
indicator; 240 parts of bromine correspond to 58 parts of acetone. The
complete analysis can be performed in one and a half to two hours. It is
imperative that the bromine used should be pure, as crude bromine
frequently contains bromoform. The method is suitable for the estimation of
acetone in wood-spirit, the spirit being diluted to 10 times its volume, and 5
c.c. of this solution employed for the determination. For example—
(1.) Three c.c. of a solution containing 9.61 per cent. acetone gave 1.7850
grm. KBr. Acetone found = 9.66 per cent.
Page 227
(2.) Ten c.c. of a solution containing 0.96 per cent. acetone gave 0.5847
grm. KBr. Acetone found = 0.95 per cent.
~Nitro-Cotton.~—The first thing upon opening a case of wet cotton, or in
receiving a sample from the "poacher," that requires to be determined is the
percentage of water that it contains. It is best done by weighing out about
1,000 grms. upon a paper tray, which has been previously dried in the oven
at 100° C. for some time, and become constant in weight. The trayful of
cotton is then placed in a water oven, kept at 100° C., and dried as long as it
loses water. The loss gives the percentage of water. It varies from 20 to 30
per cent. as a rule in "wet" cotton.
OUTLINE SCHEME FOR THE ANALYSIS OF NITRO-EXPLOSIVES
_____________________________________________________________
__________ | | | Exhaust dried substance with Anhydrous Ether in Soxhlet's
Fat | | Extraction Apparatus. |
|____________________________________________________________
___________| | | | Solution—Divide into two parts ~A.~ and ~B.~ |
|____________________________________________________________
___________| | | | ~A.~ | | | | Allow ether to evaporate spontaneously. Dry
residue in vacuo over | | H_{2}SO_{4} and weigh. Equals nitro-glycerine,
resin, camphor, and | | paraffin. | | | | The nitro-glycerine in this residue may
be decomposed by heating | | with a solution of alcoholic potash. Water may
then be added, and the | | alcohol evaporated off on the water bath. From
this solution the | | resin may be precipitated by HCl, filtered off, dried, and
weighed. | | Solution containing the paraffin is treated with AmS solution
and | | heated. On cooling the paraffin separates, and may be separated. | |
Residue may be shaken with CS_{2} to remove camphor. |
|____________________________________________________________
___________| | | | ~B.~ | | | | Add phenol-phthalein and titrate with alcoholic
potash, 1 c.c. normal | | KHO = .330 grm. resin, and add considerably more
grm. KBr. Acetone found = 0.95 per cent.
~Nitro-Cotton.~—The first thing upon opening a case of wet cotton, or in
receiving a sample from the "poacher," that requires to be determined is the
percentage of water that it contains. It is best done by weighing out about
1,000 grms. upon a paper tray, which has been previously dried in the oven
at 100° C. for some time, and become constant in weight. The trayful of
cotton is then placed in a water oven, kept at 100° C., and dried as long as it
loses water. The loss gives the percentage of water. It varies from 20 to 30
per cent. as a rule in "wet" cotton.
OUTLINE SCHEME FOR THE ANALYSIS OF NITRO-EXPLOSIVES
_____________________________________________________________
__________ | | | Exhaust dried substance with Anhydrous Ether in Soxhlet's
Fat | | Extraction Apparatus. |
|____________________________________________________________
___________| | | | Solution—Divide into two parts ~A.~ and ~B.~ |
|____________________________________________________________
___________| | | | ~A.~ | | | | Allow ether to evaporate spontaneously. Dry
residue in vacuo over | | H_{2}SO_{4} and weigh. Equals nitro-glycerine,
resin, camphor, and | | paraffin. | | | | The nitro-glycerine in this residue may
be decomposed by heating | | with a solution of alcoholic potash. Water may
then be added, and the | | alcohol evaporated off on the water bath. From
this solution the | | resin may be precipitated by HCl, filtered off, dried, and
weighed. | | Solution containing the paraffin is treated with AmS solution
and | | heated. On cooling the paraffin separates, and may be separated. | |
Residue may be shaken with CS_{2} to remove camphor. |
|____________________________________________________________
___________| | | | ~B.~ | | | | Add phenol-phthalein and titrate with alcoholic
potash, 1 c.c. normal | | KHO = .330 grm. resin, and add considerably more
Page 228
KHO. Evaporate, | | dissolve residue in water, shake with ether, and
separate. |
|____________________________________________________________
___________| | | | Ethereal Solution evaporated leaves paraffin. |
|____________________________________________________________
___________| | | | Aqueous Solution— | | Add bromide, acidify with HCl,
separate any resin and precipitate, | | filtrate with BaCl_{2} BaSO_{4} x
.1373 = Sulphur. |
|____________________________________________________________
___________| | | | Residue— | | Dry, weigh, and exhaust with water
preferably in Soxhlet. |
|____________________________________________________________
___________| | | | | Solution— | Residue— | | Contains metallic | Dry, weigh,
and agitate an aliquot part with | | nitrates, chlorates, | with H_{2}SO_{4}
and Hg in nitrometer. If | | soluble carbonates, | nitro-cellulose is present,
treat remainder of | | the sum of which | residue with ether-alcohol. | |
(except AmCO_{3})
|________________________________________________| | can be
determined by | | | evaporating down at | Solution— | | 100° C. to dryness |
Evaporate and weigh. Residue consists of | | and weighing. | soluble nitro-
cellulose. | | Nitrates can be
|________________________________________________| | determined
by | | | | Residue— | | | Dry and weigh and determine hexa-nitro- | | |
cellulose in nitrometer, if present. Exhaust | | | remainder with acetic ether. | |
|________________________________________________| | | | | | |
Solution— | Residue— | | | Hexa-nitro-cellulose | Dry and weigh, ignite | | |
(Gun cotton). | and reweigh. Loss = | | | | Cellulose. | | |
|_________________________| | | | | | | | Residue consists of | | | | sawdust,
charcoal, | | | | coal, chalk, guhr, | | | | or mineral matter, &c. |
separate. |
|____________________________________________________________
___________| | | | Ethereal Solution evaporated leaves paraffin. |
|____________________________________________________________
___________| | | | Aqueous Solution— | | Add bromide, acidify with HCl,
separate any resin and precipitate, | | filtrate with BaCl_{2} BaSO_{4} x
.1373 = Sulphur. |
|____________________________________________________________
___________| | | | Residue— | | Dry, weigh, and exhaust with water
preferably in Soxhlet. |
|____________________________________________________________
___________| | | | | Solution— | Residue— | | Contains metallic | Dry, weigh,
and agitate an aliquot part with | | nitrates, chlorates, | with H_{2}SO_{4}
and Hg in nitrometer. If | | soluble carbonates, | nitro-cellulose is present,
treat remainder of | | the sum of which | residue with ether-alcohol. | |
(except AmCO_{3})
|________________________________________________| | can be
determined by | | | evaporating down at | Solution— | | 100° C. to dryness |
Evaporate and weigh. Residue consists of | | and weighing. | soluble nitro-
cellulose. | | Nitrates can be
|________________________________________________| | determined
by | | | | Residue— | | | Dry and weigh and determine hexa-nitro- | | |
cellulose in nitrometer, if present. Exhaust | | | remainder with acetic ether. | |
|________________________________________________| | | | | | |
Solution— | Residue— | | | Hexa-nitro-cellulose | Dry and weigh, ignite | | |
(Gun cotton). | and reweigh. Loss = | | | | Cellulose. | | |
|_________________________| | | | | | | | Residue consists of | | | | sawdust,
charcoal, | | | | coal, chalk, guhr, | | | | or mineral matter, &c. |
Page 229
|______________________|______________________|_______________
__________|
NOTE.—Camphor is found by difference. Sulphur is only partially
soluble in ether. It is better, therefore, to extract some of the original
substance with water, and treat residue with alcoholic KHO. Add bromide,
acidify, and precipitate as BaSO.
~The Solubility Test.~—The object of this test is to ascertain, in the case
of gun-cotton, the percentage of soluble (penta and lower nitrates) cotton
that it contains, or in the case of soluble cotton, the quantity of gun-cotton.
The method of procedure is as follows:—Five grms. of the sample which
has been previously dried at 100° C., and afterwards exposed to the air for
two hours, is transferred to a conical flask, and 250 c.c. ether-alcohol added
(2 ether to 1 alcohol). The flask is then corked and allowed to digest, with
repeated shaking, for two or three hours. The whole is then transferred to a
linen filter, and when the solution has passed through the filter, is washed
with a little ether, and pressed in a hand-screw press between folds of filter
paper. The sample is then returned to the flask, and the previous treatment
repeated, but it will be sufficient for it to digest for one hour the second
time. The filter is then again pressed first gently by hand, then in the press,
and afterwards opened up and the ether allowed to evaporate. The gun-
cotton is then removed from the filter and transferred to a watch-glass, and
dried in the water oven at 100° C. When dry it is exposed to the air for two
hours and weighed. It equals the amount of gun-cotton and unconverted
cotton in the 5 grms. The unconverted cotton must be determined in a
separate 5 grms. and deducted.
The method of determining the soluble cotton now used in the
Government laboratories is as follows:—Fifty grains of the nitro-cotton are
dissolved in 150 c.c. of ether-alcohol, and allowed to stand, with frequent
__________|
NOTE.—Camphor is found by difference. Sulphur is only partially
soluble in ether. It is better, therefore, to extract some of the original
substance with water, and treat residue with alcoholic KHO. Add bromide,
acidify, and precipitate as BaSO.
~The Solubility Test.~—The object of this test is to ascertain, in the case
of gun-cotton, the percentage of soluble (penta and lower nitrates) cotton
that it contains, or in the case of soluble cotton, the quantity of gun-cotton.
The method of procedure is as follows:—Five grms. of the sample which
has been previously dried at 100° C., and afterwards exposed to the air for
two hours, is transferred to a conical flask, and 250 c.c. ether-alcohol added
(2 ether to 1 alcohol). The flask is then corked and allowed to digest, with
repeated shaking, for two or three hours. The whole is then transferred to a
linen filter, and when the solution has passed through the filter, is washed
with a little ether, and pressed in a hand-screw press between folds of filter
paper. The sample is then returned to the flask, and the previous treatment
repeated, but it will be sufficient for it to digest for one hour the second
time. The filter is then again pressed first gently by hand, then in the press,
and afterwards opened up and the ether allowed to evaporate. The gun-
cotton is then removed from the filter and transferred to a watch-glass, and
dried in the water oven at 100° C. When dry it is exposed to the air for two
hours and weighed. It equals the amount of gun-cotton and unconverted
cotton in the 5 grms. The unconverted cotton must be determined in a
separate 5 grms. and deducted.
The method of determining the soluble cotton now used in the
Government laboratories is as follows:—Fifty grains of the nitro-cotton are
dissolved in 150 c.c. of ether-alcohol, and allowed to stand, with frequent
Page 230
shakings, in a 200 c.c. stoppered measure for six hours; 75 c.c. of the clear
solution are then drawn off by the aid of a pipette and evaporated in a dish
on the water bath, and finally in the water oven at 120° F. (49° C.), until
constant in weight. The weight found equals the quantity of soluble cotton
in the 75 c.c., which, multiplied by 4, equals the percentage, thus: Suppose
that 2.30 grains was the weight found, then
(2.3 x 150)/75 = 4.6 in 50 = 9.20 per cent.
A method for the determination of soluble nitro-cellulose in gun-cotton
and smokeless powder has been published by K.B. Quinan (Jour. Amer.
Chem. Soc., 23 [4], 258). In this method about 1 grm. of the finely divided
dry sample to be analysed is placed in an aluminium cup 1.9 inch in
diameter and 4-1/8 inch deep. It is then covered and well stirred with 50 c.c.
of alcohol, 100 c.c. of ether are then added, and the mixture is stirred for
several minutes. After removing the stirrer, the cup is lightly covered with
an aluminium lid, and is then placed in the steel cup of a centrifugal
machine, which is gradually got up to a speed of 2,000 revolutions per
minute, the total centrifugal force at the position occupied by the cups
(which become horizontal when in rapid rotation) is about 450 lbs. They are
rotated at the full speed for ten to twelve minutes, and the machine is then
gradually stopped. By this time the whole of the insoluble matter will be at
the bottom of the cup, and the supernatant solution will be clear. It is drawn
off to within a quarter of an inch of the bottom (without disturbing the
sediment), with the aid of a pipette.
Care must be taken that the solution thus withdrawn is perfectly clear.
About 10 to 15 c.c. of colloid solution and a film of insoluble matter remain
at the bottom of the cup; these are stirred up well, the stirrer is rinsed with
ether-alcohol, about 50 c.c. of fresh ether-alcohol are added; the mixture is
again treated in the centrifugal apparatus for about eight minutes; the whole
solution are then drawn off by the aid of a pipette and evaporated in a dish
on the water bath, and finally in the water oven at 120° F. (49° C.), until
constant in weight. The weight found equals the quantity of soluble cotton
in the 75 c.c., which, multiplied by 4, equals the percentage, thus: Suppose
that 2.30 grains was the weight found, then
(2.3 x 150)/75 = 4.6 in 50 = 9.20 per cent.
A method for the determination of soluble nitro-cellulose in gun-cotton
and smokeless powder has been published by K.B. Quinan (Jour. Amer.
Chem. Soc., 23 [4], 258). In this method about 1 grm. of the finely divided
dry sample to be analysed is placed in an aluminium cup 1.9 inch in
diameter and 4-1/8 inch deep. It is then covered and well stirred with 50 c.c.
of alcohol, 100 c.c. of ether are then added, and the mixture is stirred for
several minutes. After removing the stirrer, the cup is lightly covered with
an aluminium lid, and is then placed in the steel cup of a centrifugal
machine, which is gradually got up to a speed of 2,000 revolutions per
minute, the total centrifugal force at the position occupied by the cups
(which become horizontal when in rapid rotation) is about 450 lbs. They are
rotated at the full speed for ten to twelve minutes, and the machine is then
gradually stopped. By this time the whole of the insoluble matter will be at
the bottom of the cup, and the supernatant solution will be clear. It is drawn
off to within a quarter of an inch of the bottom (without disturbing the
sediment), with the aid of a pipette.
Care must be taken that the solution thus withdrawn is perfectly clear.
About 10 to 15 c.c. of colloid solution and a film of insoluble matter remain
at the bottom of the cup; these are stirred up well, the stirrer is rinsed with
ether-alcohol, about 50 c.c. of fresh ether-alcohol are added; the mixture is
again treated in the centrifugal apparatus for about eight minutes; the whole
Page 231
washing process is then repeated until all soluble matter has been removed.
This may require about seven or eight (or for samples with much insoluble
matter ten or twelve or more) washings, but as the extraction proceeds, the
period of rotation may be somewhat reduced. After extraction is completed,
the insoluble matter is transferred to a Gooch crucible with the usual
asbestos pad, dried at 100° C., and weighed. The residue may, if wished, be
dried and weighed in the aluminium cup, but then it cannot be ignited. The
whole time for an analysis exclusive of that required for drying, is from one
to two hours—average time, 1-1/4 hour. The results are satisfactory both as
to accuracy and rapidity. Acetone-soluble nitro-cellulose may be determined
by the same method.
~The Unconverted or Non-nitrated Cotton.~—However well the cotton
has been nitrated, it is almost certain to contain a small quantity of non-
nitrated or unconverted cotton. This can be determined thus:—Five grms. of
the sample are boiled with a saturated solution of sodium sulphide, and then
allowed to stand for forty-eight hours, and afterwards filtered or decanted,
and again boiled with fresh solutions of sulphide, and again filtered, washed
first with dilute HCl and then with water, dried, and weighed. The residue is
the cellulose that was not nitrated, plus ash, &c. It should be ignited, and
the weight of the ash deducted from the previous weight.
Acetone, and acetic-ether (ethyl-acetate) may also be used as solvents for
the nitro-cellulose. Another process is to boil the gun-cotton, &c., in a
solution of sodium stannate made by adding caustic soda to a solution of
stannous chloride, until the precipitate first formed is just re-dissolved. This
solution dissolves the cellulose nitrates, but does not affect the cellulose. Dr
Lungé found the following process more satisfactory in the case of the more
highly nitrated products:—The reagent is an alcoholic solution of sodium-
ethylate prepared by dissolving 2 to 3 grms. of sodium in 100 c.c. of 95 per
cent. alcohol, and mixing the filtered solution with 100 c.c. of acetone. It
This may require about seven or eight (or for samples with much insoluble
matter ten or twelve or more) washings, but as the extraction proceeds, the
period of rotation may be somewhat reduced. After extraction is completed,
the insoluble matter is transferred to a Gooch crucible with the usual
asbestos pad, dried at 100° C., and weighed. The residue may, if wished, be
dried and weighed in the aluminium cup, but then it cannot be ignited. The
whole time for an analysis exclusive of that required for drying, is from one
to two hours—average time, 1-1/4 hour. The results are satisfactory both as
to accuracy and rapidity. Acetone-soluble nitro-cellulose may be determined
by the same method.
~The Unconverted or Non-nitrated Cotton.~—However well the cotton
has been nitrated, it is almost certain to contain a small quantity of non-
nitrated or unconverted cotton. This can be determined thus:—Five grms. of
the sample are boiled with a saturated solution of sodium sulphide, and then
allowed to stand for forty-eight hours, and afterwards filtered or decanted,
and again boiled with fresh solutions of sulphide, and again filtered, washed
first with dilute HCl and then with water, dried, and weighed. The residue is
the cellulose that was not nitrated, plus ash, &c. It should be ignited, and
the weight of the ash deducted from the previous weight.
Acetone, and acetic-ether (ethyl-acetate) may also be used as solvents for
the nitro-cellulose. Another process is to boil the gun-cotton, &c., in a
solution of sodium stannate made by adding caustic soda to a solution of
stannous chloride, until the precipitate first formed is just re-dissolved. This
solution dissolves the cellulose nitrates, but does not affect the cellulose. Dr
Lungé found the following process more satisfactory in the case of the more
highly nitrated products:—The reagent is an alcoholic solution of sodium-
ethylate prepared by dissolving 2 to 3 grms. of sodium in 100 c.c. of 95 per
cent. alcohol, and mixing the filtered solution with 100 c.c. of acetone. It
Page 232
has no effect upon cellulose, but decomposes nitro-cellulose with the
formation of a reddish brown compound, which is soluble in water. In the
determination, 5 grms. of gun-cotton are heated to 40° or 50° C. on the
water bath with 150 c.c. of the reagent, the liquid being shaken at intervals
for twenty to thirty minutes; or the mixture may be allowed to stand for a
few hours at the ordinary temperature. The brown-red solution is decanted
from the undissolved residue, and the latter washed with alcohol and with
water, by decantation, and then on the filter with hot water, to which a little
hydrochloric acid is added for the final washings. For ordinary work this
cellulose is dried immediately and weighed, but in exact determinations it is
washed with alcohol, again treated with 50 c.c. of the reagent, and separated
and washed as before. The cellulose thus obtained, gives no trace of gas in
the nitrometer, and duplicate determinations agree within 0.1 to 0.2 per
cent. when the weight of unchanged cellulose amounts to about 0.2 grm.
Gun-cotton, which is completely soluble in acetone, contains only traces of
cellulose, and when as much as 0.85 per cent. is present it does not dissolve
entirely. This method is not applicable to the determination of cellulose in
lower nitrated products, and Dr Lungé attributes this to the fact that these
being prepared with less concentrated acid invariably contain oxy-cellulose.
~Alkalinity.~—Five grms. of the air-dried and very finely divided sample
are taken from the centre of the slabs or discs, and digested with about 20
c.c. of N/2 hydrochloric acid, and diluted with water to about 250 c.c., and
shaken for about fifteen minutes. The liquid is then decanted, and washed
with water until the washings no longer give an acid reaction. The solution,
together with the washings, are titrated with N/4 sodium carbonate, using
litmus as indicator.
~Ash and Inorganic Matter.~—This is best determined by mixing 2 or 3
grms. of the nitro-cotton in a platinum crucible with shavings of paraffin,
heating sufficiently to melt the paraffin, and then allowing the contents of
formation of a reddish brown compound, which is soluble in water. In the
determination, 5 grms. of gun-cotton are heated to 40° or 50° C. on the
water bath with 150 c.c. of the reagent, the liquid being shaken at intervals
for twenty to thirty minutes; or the mixture may be allowed to stand for a
few hours at the ordinary temperature. The brown-red solution is decanted
from the undissolved residue, and the latter washed with alcohol and with
water, by decantation, and then on the filter with hot water, to which a little
hydrochloric acid is added for the final washings. For ordinary work this
cellulose is dried immediately and weighed, but in exact determinations it is
washed with alcohol, again treated with 50 c.c. of the reagent, and separated
and washed as before. The cellulose thus obtained, gives no trace of gas in
the nitrometer, and duplicate determinations agree within 0.1 to 0.2 per
cent. when the weight of unchanged cellulose amounts to about 0.2 grm.
Gun-cotton, which is completely soluble in acetone, contains only traces of
cellulose, and when as much as 0.85 per cent. is present it does not dissolve
entirely. This method is not applicable to the determination of cellulose in
lower nitrated products, and Dr Lungé attributes this to the fact that these
being prepared with less concentrated acid invariably contain oxy-cellulose.
~Alkalinity.~—Five grms. of the air-dried and very finely divided sample
are taken from the centre of the slabs or discs, and digested with about 20
c.c. of N/2 hydrochloric acid, and diluted with water to about 250 c.c., and
shaken for about fifteen minutes. The liquid is then decanted, and washed
with water until the washings no longer give an acid reaction. The solution,
together with the washings, are titrated with N/4 sodium carbonate, using
litmus as indicator.
~Ash and Inorganic Matter.~—This is best determined by mixing 2 or 3
grms. of the nitro-cotton in a platinum crucible with shavings of paraffin,
heating sufficiently to melt the paraffin, and then allowing the contents of
Page 233
the crucible to catch fire and burn away quietly. The temperature is then
raised, and the carbonaceous residue incinerated, cooled, weighed, &c., and
the percentage of ash calculated. Schjerning proceeds in the following way:
—He takes 5 grms. of the nitro-cotton in a large platinum crucible, he then
moistens it with a mixture of alcohol and ether, in which paraffin has been
dissolved to saturation, and filtered and mixed with one-fourth of its
volume of water. Some fragments of solid paraffin are then added, and the
ether set on fire. Whilst this is in progress the crucible is kept in an oblique
position, and is rotated so that the gun-cotton may absorb the paraffin
uniformly. The partially charred residue is now rubbed down with a
rounded glass rod, and the crucible is covered and heated for from fifteen to
twenty minutes over the blow-pipe, the lid being occasionally removed. The
residue is soon converted into ash, which is weighed, and then washed out
into a porcelain basin and treated with hydrochloric acid heated to 90° C.
The oxide of iron, alumina, lime, and magnesia are thus dissolved, and the
silica remains as insoluble residue. The rest of the analysis is conducted
according to the well-known methods of separation. The percentage of ash
as a whole is generally all that is required.
~Examination of Nitrated Celluloses with Polarised Light.~—Dr G.
Lungé (Jour. Amer. Chem. Soc., 1901, 23 [8], 527) has formed the following
conclusions:—The most highly nitrated products appear blue in polarised
light, but those containing between 13.9 and 13.0 per cent. of nitrogen
cannot be distinguished from each other by polarisation. As the percentage
of nitrogen rises, the blue colour becomes less intense, and here and there
grey fibres can be observed, though not in proportion to the increase in the
nitrogen. Below 12.4 per cent. of nitrogen, the fibres show a grey lustre,
which usually appears yellow when the top light is cut off. Below 10 per
cent. of nitrogen, the structure is invariably partially destroyed and no
certain observations possible. It is only possible to distinguish with
certainty, firstly any unchanged cellulose by its flashing up in variegated
raised, and the carbonaceous residue incinerated, cooled, weighed, &c., and
the percentage of ash calculated. Schjerning proceeds in the following way:
—He takes 5 grms. of the nitro-cotton in a large platinum crucible, he then
moistens it with a mixture of alcohol and ether, in which paraffin has been
dissolved to saturation, and filtered and mixed with one-fourth of its
volume of water. Some fragments of solid paraffin are then added, and the
ether set on fire. Whilst this is in progress the crucible is kept in an oblique
position, and is rotated so that the gun-cotton may absorb the paraffin
uniformly. The partially charred residue is now rubbed down with a
rounded glass rod, and the crucible is covered and heated for from fifteen to
twenty minutes over the blow-pipe, the lid being occasionally removed. The
residue is soon converted into ash, which is weighed, and then washed out
into a porcelain basin and treated with hydrochloric acid heated to 90° C.
The oxide of iron, alumina, lime, and magnesia are thus dissolved, and the
silica remains as insoluble residue. The rest of the analysis is conducted
according to the well-known methods of separation. The percentage of ash
as a whole is generally all that is required.
~Examination of Nitrated Celluloses with Polarised Light.~—Dr G.
Lungé (Jour. Amer. Chem. Soc., 1901, 23 [8], 527) has formed the following
conclusions:—The most highly nitrated products appear blue in polarised
light, but those containing between 13.9 and 13.0 per cent. of nitrogen
cannot be distinguished from each other by polarisation. As the percentage
of nitrogen rises, the blue colour becomes less intense, and here and there
grey fibres can be observed, though not in proportion to the increase in the
nitrogen. Below 12.4 per cent. of nitrogen, the fibres show a grey lustre,
which usually appears yellow when the top light is cut off. Below 10 per
cent. of nitrogen, the structure is invariably partially destroyed and no
certain observations possible. It is only possible to distinguish with
certainty, firstly any unchanged cellulose by its flashing up in variegated
Page 234
(rainbow) colours; and secondly, highly nitrated products (from 12.75 per
cent. N upwards), by their flashing up less strongly in blue colours. The
purple transition stage in the fibres containing over 11.28 per cent. of N
(Chardonnet) was not observed by Dr Lungé.
~Determination of Nitrogen by Lungé Nitrometer.~—The determination
of the percentage of nitrogen in a sample of gun-cotton or collodion is
perhaps of more value, and affords a better idea of its purity and
composition, than any of the foregoing methods of examination, and taken
in conjunction with the solubility test, it will generally give the analyst a
very fair idea of the composition of his sample. If we regard gun-cotton as
the hexa-nitro-cellulose, the theoretical amount of nitrogen required for the
formula is 14.14 per cent., and in the same way for collodion-cotton, which
consists of the lower nitrates, chiefly, however, of the penta- nitrate, the
theoretical nitrogen is 12.75 per cent., so that if in a sample of nitro-cotton
the nitrogen falls much lower than 14 per cent., it probably contains
considerable quantities of the lower nitrates, and perhaps some non-nitrated
cellulose as well (C_{6}H_{10}O_{5})_{x}, which of course would also
lower the percentage of nitrogen.
The most expeditious method of determining the nitrogen in these nitro
bodies is by the use of Lungé's nitrometer (Fig. 41), and the best way of
working the process is as follows:—Weigh out with the greatest care 0.6
grm. of the previously dried substance in a small weighing bottle of about
15 c.c. capacity, and carefully add 10 c.c. of concentrated sulphuric acid
from a pipette, and allow to stand until all the cotton is dissolved. The
nitrometer should be of a capacity 150 to 200 c.c., and should contain a
bulb of 100 c.c. capacity at the top, and should be fitted with a Greiner and
Friederich's three-way tap. When the nitro-cotton has entirely dissolved to a
clear solution, raise the pressure tube of the nitrometer so as to bring the
mercury in the measuring tube close up to the tap. Open the tap in order to
cent. N upwards), by their flashing up less strongly in blue colours. The
purple transition stage in the fibres containing over 11.28 per cent. of N
(Chardonnet) was not observed by Dr Lungé.
~Determination of Nitrogen by Lungé Nitrometer.~—The determination
of the percentage of nitrogen in a sample of gun-cotton or collodion is
perhaps of more value, and affords a better idea of its purity and
composition, than any of the foregoing methods of examination, and taken
in conjunction with the solubility test, it will generally give the analyst a
very fair idea of the composition of his sample. If we regard gun-cotton as
the hexa-nitro-cellulose, the theoretical amount of nitrogen required for the
formula is 14.14 per cent., and in the same way for collodion-cotton, which
consists of the lower nitrates, chiefly, however, of the penta- nitrate, the
theoretical nitrogen is 12.75 per cent., so that if in a sample of nitro-cotton
the nitrogen falls much lower than 14 per cent., it probably contains
considerable quantities of the lower nitrates, and perhaps some non-nitrated
cellulose as well (C_{6}H_{10}O_{5})_{x}, which of course would also
lower the percentage of nitrogen.
The most expeditious method of determining the nitrogen in these nitro
bodies is by the use of Lungé's nitrometer (Fig. 41), and the best way of
working the process is as follows:—Weigh out with the greatest care 0.6
grm. of the previously dried substance in a small weighing bottle of about
15 c.c. capacity, and carefully add 10 c.c. of concentrated sulphuric acid
from a pipette, and allow to stand until all the cotton is dissolved. The
nitrometer should be of a capacity 150 to 200 c.c., and should contain a
bulb of 100 c.c. capacity at the top, and should be fitted with a Greiner and
Friederich's three-way tap. When the nitro-cotton has entirely dissolved to a
clear solution, raise the pressure tube of the nitrometer so as to bring the
mercury in the measuring tube close up to the tap. Open the tap in order to
Page 235
allow of the escape of any air bubbles, and clean the surface of the mercury
and the inside of the cup with a small piece of filter paper. Now close the
tap, and pour the solution of the nitro-cotton into the cup. Rinse out the
bottle with 15 c.c. of sulphuric acid, contained in a pipette, pouring a little
of the acid over the stopper of the weighing bottle in case some of the
solution may be on it. Now lower the pressure tube a little, just enough to
cause the solution to flow into the bulb of the measuring tube, when the tap
is slightly opened. When the solution has run in almost to the end, turn off
the tap, wash down the sides of the bottle, and add to the cup of the
nitrometer; allow it to flow in as before, and then wash down the sides of
the cup with 10 c.c. of sulphuric acid, adding little by little, and allowing
each portion added to flow into the bulb of the nitrometer before adding the
next portion. Great care is necessary to prevent air bubbles obtaining
admission, and if the pressure tube is lowered too far, the acid will run with
a rush and carry air along with it.
[Illustration: FIG. 41.—ORDINARY FORM OF LUNGÉ
NITROMETER.]
The solution being all in the measuring tube, the pressure tube is again
slightly raised, and the tube containing the nitro-cotton solution shaken for
ten minutes with considerable violence. It is then replaced in the clamp, and
the pressure relieved by lowering the pressure tube, and the whole
apparatus allowed to stand for twenty minutes, in order to allow the gas
evolved to assume the temperature of the room. A thermometer should be
hung up close to the bulb of the measuring tube. At the end of the twenty
minutes, the levels of the mercury in the pressure and measuring tubes are
equalised, and the final adjustment obtained by slightly opening the tap on
the measuring tube (very slightly), after first adding a little sulphuric acid to
the cup, and observing whether the acid runs in or moves up. This must be
done with very great care. When accurately adjusted, it should move neither
and the inside of the cup with a small piece of filter paper. Now close the
tap, and pour the solution of the nitro-cotton into the cup. Rinse out the
bottle with 15 c.c. of sulphuric acid, contained in a pipette, pouring a little
of the acid over the stopper of the weighing bottle in case some of the
solution may be on it. Now lower the pressure tube a little, just enough to
cause the solution to flow into the bulb of the measuring tube, when the tap
is slightly opened. When the solution has run in almost to the end, turn off
the tap, wash down the sides of the bottle, and add to the cup of the
nitrometer; allow it to flow in as before, and then wash down the sides of
the cup with 10 c.c. of sulphuric acid, adding little by little, and allowing
each portion added to flow into the bulb of the nitrometer before adding the
next portion. Great care is necessary to prevent air bubbles obtaining
admission, and if the pressure tube is lowered too far, the acid will run with
a rush and carry air along with it.
[Illustration: FIG. 41.—ORDINARY FORM OF LUNGÉ
NITROMETER.]
The solution being all in the measuring tube, the pressure tube is again
slightly raised, and the tube containing the nitro-cotton solution shaken for
ten minutes with considerable violence. It is then replaced in the clamp, and
the pressure relieved by lowering the pressure tube, and the whole
apparatus allowed to stand for twenty minutes, in order to allow the gas
evolved to assume the temperature of the room. A thermometer should be
hung up close to the bulb of the measuring tube. At the end of the twenty
minutes, the levels of the mercury in the pressure and measuring tubes are
equalised, and the final adjustment obtained by slightly opening the tap on
the measuring tube (very slightly), after first adding a little sulphuric acid to
the cup, and observing whether the acid runs in or moves up. This must be
done with very great care. When accurately adjusted, it should move neither
Page 236
way. Now read off the volume of the NO gas in cubic centimetres from the
measuring tube. Read also the thermometer suspended near the bulb, and
take the height of the barometer in millimetres. The calculation is very
simple.
EXAMPLE—COLLODION-COTTON.
0.6[A] grm. taken. Reading on measuring tube = 114.6 c.c. NO.
Barometer— 758 mm. Temperature—15° C.
[Footnote A: 0.5 grm. is enough in the case of gun-cotton.]
Since 1 c.c. NO = 0.6272 milligramme N, and correcting for temperature
and pressure by the formula
760 x (1 + d^{2}) (d = .003665), for temperature 15° = 801.78,[A]
measuring tube. Read also the thermometer suspended near the bulb, and
take the height of the barometer in millimetres. The calculation is very
simple.
EXAMPLE—COLLODION-COTTON.
0.6[A] grm. taken. Reading on measuring tube = 114.6 c.c. NO.
Barometer— 758 mm. Temperature—15° C.
[Footnote A: 0.5 grm. is enough in the case of gun-cotton.]
Since 1 c.c. NO = 0.6272 milligramme N, and correcting for temperature
and pressure by the formula
760 x (1 + d^{2}) (d = .003665), for temperature 15° = 801.78,[A]
Page 237
then
(114.6 x 100 x 750 x .6272)/(801.7 x. 6) = 11.22 per cent. nitrogen.
[Footnote A: See Table, page 244.]
The nitrogen in nitro-glycerine may of course be determined by the
nitrometer, but in this case it is better to take a much smaller quantity of the
substance. From 0.1 to 0.2 grm. is quite sufficient. This will give from 30 to
60 c.c. of gas, and therefore a measuring tube without a 100 c.c. bulb must
be used.
EXAMPLE.
0.1048 grm. nitroglycerine taken gave 32.5 c.c. NO. Barometer, 761 mm.
Temperature, 15° C.
Therefore,
(3.25 x 100 x 761 x .6272)/(801.78 x.1048) = 18.46 per cent. N. Theory =
18.50 per cent.
Professor Lungé has devised another form of nitrometer (Fig. 42), very
useful in the nitrogen determination in explosives. It consists of a
measuring tube, which is widened out in the middle to a bulb, and is
graduated above and below into 1/10 c.c. The capacity of the whole
apparatus is 130 c.c.; that of each portion of the tube being 30 c.c., and of
the bulb 70 c.c. The upper portion of the graduated tube serves to measure
small volumes of gas, whilst larger volumes are read off on the lower part.
[Illustration: FIG. 42. FIG. 43. SOME NEW FORMS OF
NITROMETER.]
(114.6 x 100 x 750 x .6272)/(801.7 x. 6) = 11.22 per cent. nitrogen.
[Footnote A: See Table, page 244.]
The nitrogen in nitro-glycerine may of course be determined by the
nitrometer, but in this case it is better to take a much smaller quantity of the
substance. From 0.1 to 0.2 grm. is quite sufficient. This will give from 30 to
60 c.c. of gas, and therefore a measuring tube without a 100 c.c. bulb must
be used.
EXAMPLE.
0.1048 grm. nitroglycerine taken gave 32.5 c.c. NO. Barometer, 761 mm.
Temperature, 15° C.
Therefore,
(3.25 x 100 x 761 x .6272)/(801.78 x.1048) = 18.46 per cent. N. Theory =
18.50 per cent.
Professor Lungé has devised another form of nitrometer (Fig. 42), very
useful in the nitrogen determination in explosives. It consists of a
measuring tube, which is widened out in the middle to a bulb, and is
graduated above and below into 1/10 c.c. The capacity of the whole
apparatus is 130 c.c.; that of each portion of the tube being 30 c.c., and of
the bulb 70 c.c. The upper portion of the graduated tube serves to measure
small volumes of gas, whilst larger volumes are read off on the lower part.
[Illustration: FIG. 42. FIG. 43. SOME NEW FORMS OF
NITROMETER.]
Page 238
F.M. Horn (Zeitschrift für angewandte Chemie, 1892, p. 358) has devised
a form of nitrometer (Fig. 43) which he has found especially useful in the
examination of smokeless powders. The tap H is provided with a wide bore
through which a weighed quantity of the powder is dropped bodily into the
bulb K. From 4 to 5 c.c. of sulphuric acid which has been heated to 30° C.
are then added through the funnel T, the tap H being immediately closed.
When the powder has dissolved—a process which may be hastened by
warming the bulb very carefully—the thick solution is drawn into the
nitrometer tube N, and the bulb rinsed several times with fresh acid, after
which operation the analysis is proceeded with in the usual way.
Dr Lungé's method of using a separate nitrometer in which to measure
the NO gas evolved to the one in which the reaction has taken place, the gas
being transferred from the one to the other by joining them by means of
indiarubber tubing, and then driving the gas over by raising the pressure
tube of the one containing the gas, the taps being open, I have found to be a
great improvement.
1 c.c. NO gas at 0° and 760 mm.
Equals 0.6272 milligrammes (N) nitrogen.
" 1.343 " nitric oxide.
" 2.820 " (HNO_{3}) nitric acid.
" 3.805 " (NaNO_{3}) sodium nitrate.
" 4.523 " (KNO_{3}) potassium nitrate.
~Champion and Pellet's Method.~—This method is now very little used.
It is based upon the fact that when nitro-cellulose is boiled with ferrous
chloride and hydrochloric acid, all the nitrogen is disengaged as nitric oxide
(NO). It is performed as follows:—A vacuum is made in a flask, fitted with
a funnel tube, with a glass stopper on the tube; a delivery tube that can also
be closed, and which dips under a solution of caustic soda contained in a
a form of nitrometer (Fig. 43) which he has found especially useful in the
examination of smokeless powders. The tap H is provided with a wide bore
through which a weighed quantity of the powder is dropped bodily into the
bulb K. From 4 to 5 c.c. of sulphuric acid which has been heated to 30° C.
are then added through the funnel T, the tap H being immediately closed.
When the powder has dissolved—a process which may be hastened by
warming the bulb very carefully—the thick solution is drawn into the
nitrometer tube N, and the bulb rinsed several times with fresh acid, after
which operation the analysis is proceeded with in the usual way.
Dr Lungé's method of using a separate nitrometer in which to measure
the NO gas evolved to the one in which the reaction has taken place, the gas
being transferred from the one to the other by joining them by means of
indiarubber tubing, and then driving the gas over by raising the pressure
tube of the one containing the gas, the taps being open, I have found to be a
great improvement.
1 c.c. NO gas at 0° and 760 mm.
Equals 0.6272 milligrammes (N) nitrogen.
" 1.343 " nitric oxide.
" 2.820 " (HNO_{3}) nitric acid.
" 3.805 " (NaNO_{3}) sodium nitrate.
" 4.523 " (KNO_{3}) potassium nitrate.
~Champion and Pellet's Method.~—This method is now very little used.
It is based upon the fact that when nitro-cellulose is boiled with ferrous
chloride and hydrochloric acid, all the nitrogen is disengaged as nitric oxide
(NO). It is performed as follows:—A vacuum is made in a flask, fitted with
a funnel tube, with a glass stopper on the tube; a delivery tube that can also
be closed, and which dips under a solution of caustic soda contained in a
Page 239
trough, and the end placed under a graduated tube, also full of caustic soda.
From 0.12 to 0.16 grm. cotton dissolved in 5 to 6 c.c. of sulphuric acid is
allowed to flow into the flask, which contains the ferrous chloride and
hydrochloric acid, and in which a vacuum has been formed by boiling, and
then closing the taps. The solution is then heated, the taps on the delivery
tube opened, and the end placed under the collecting tube, and the NO
evolved collected. The NO gas is not evolved until the solution has become
somewhat concentrated. Eder substituted a solution of ferrous sulphate in
HCl for ferrous chloride. Care must be taken that the flask used is strong
enough to stand the pressure, or it will burst.
The same chemists (Compt. Rendus, lxxxiii. 707) also devised the
following method for determining the NO_{2} in nitro-glycerine:—A
known quantity of a solution of ferrous sulphate of previously ascertained
reducing power is placed in a flask, acidified with hydrochloric acid, and its
surface covered with a layer of petroleum oil. About .5 grm. of the nitro-
glycerine is then introduced, and the flask heated on the water bath. When
the sample is completely decomposed, the liquid is heated to boiling to
remove nitric oxide, and the excess of ferrous sulphate ascertained by
titration with standard permanganate; 56 of iron (Fe) oxidised by the sample
correspond to 23 of NO_{2} in the sample of nitro-glycerine.
~The Schultze-Tieman Method~ for determining nitrogen in nitro-
explosives, especially nitro-cellulose and nitro-glycerine.—The figure (No.
44) shows the general arrangement of the apparatus. I am indebted for the
following description of the method of working it to my friend, Mr William
Bate, of Hayle. To fill the apparatus with the soda solution, the gas burette
is put on the indiarubber stopper of basin W, and firmly clamped down.
Then the taps A and C are opened, and B closed. When the burette is filled
with soda solution half-way up the funnel Y, A and C are closed, and B
opened. The arrows show the inlet and outlet for the cooling water that is
From 0.12 to 0.16 grm. cotton dissolved in 5 to 6 c.c. of sulphuric acid is
allowed to flow into the flask, which contains the ferrous chloride and
hydrochloric acid, and in which a vacuum has been formed by boiling, and
then closing the taps. The solution is then heated, the taps on the delivery
tube opened, and the end placed under the collecting tube, and the NO
evolved collected. The NO gas is not evolved until the solution has become
somewhat concentrated. Eder substituted a solution of ferrous sulphate in
HCl for ferrous chloride. Care must be taken that the flask used is strong
enough to stand the pressure, or it will burst.
The same chemists (Compt. Rendus, lxxxiii. 707) also devised the
following method for determining the NO_{2} in nitro-glycerine:—A
known quantity of a solution of ferrous sulphate of previously ascertained
reducing power is placed in a flask, acidified with hydrochloric acid, and its
surface covered with a layer of petroleum oil. About .5 grm. of the nitro-
glycerine is then introduced, and the flask heated on the water bath. When
the sample is completely decomposed, the liquid is heated to boiling to
remove nitric oxide, and the excess of ferrous sulphate ascertained by
titration with standard permanganate; 56 of iron (Fe) oxidised by the sample
correspond to 23 of NO_{2} in the sample of nitro-glycerine.
~The Schultze-Tieman Method~ for determining nitrogen in nitro-
explosives, especially nitro-cellulose and nitro-glycerine.—The figure (No.
44) shows the general arrangement of the apparatus. I am indebted for the
following description of the method of working it to my friend, Mr William
Bate, of Hayle. To fill the apparatus with the soda solution, the gas burette
is put on the indiarubber stopper of basin W, and firmly clamped down.
Then the taps A and C are opened, and B closed. When the burette is filled
with soda solution half-way up the funnel Y, A and C are closed, and B
opened. The arrows show the inlet and outlet for the cooling water that is
Page 240
kept running through the water jacket round the nitrometer tube. To collect
the gas, raise the nitrometer off the rubber stopper, and place the gas tube
from the decomposition apparatus in the glass dish W and under the
opening of the nitrometer.
[Illustration: Fig. 44. SCHULTZE-TIEMAN APPARATUS.]
For the estimation of nitrogen in nitro-cellulose take .5 to .65 grm., and
place in the decomposition flask f (Fig. 45), washing in with about 25 c.c.
of water by alternately opening clips D and E. The air in the flask is driven
out by boiling, whilst the air is shut off by the tube i dipping into the basin
W, which is filled with the soda lye, and tube K is placed in the test tube R,
which contains a few c.c. of water. As soon as all the air is completely
driven out, clips D and E are closed, and the gas jet is taken away. (This
flask must be a strong one, or it will burst.) Into test tube R, 25 c.c. of
concentrated solution of protochloride of iron and 10 to 15 c.c. concentrated
hydrochloric acid are poured, which are sucked up into the developing flask
f by opening clip E, air being carefully kept from entering. The clip E is
now closed, and tube i is put underneath the burette, and the development of
NO gas is commenced by heating the contents of the flask f. When the
pressure of the gas in the flask has become greater than the pressure of the
atmosphere, the connecting tube begins to swell at i, whereupon clip D is
opened, and the boiling continued with frequent shaking of the bulb, until
no more nitrous gas bubbles rise up into the soda lye, the distilling over of
the HCl causes a crackling noise, the clip D is closed, and E opened. The
burette is again put hermetically on the indiarubber stopper in basin W, and
the apparatus is left to cool until the water discharged through P shows the
same temperature as the water flowing through (into the cooling jacket) Z.
If the level of the soda solution in the tube X is now put on exactly the same
level as that in the burette by lowering or elevating the tube X as required,
the gas, raise the nitrometer off the rubber stopper, and place the gas tube
from the decomposition apparatus in the glass dish W and under the
opening of the nitrometer.
[Illustration: Fig. 44. SCHULTZE-TIEMAN APPARATUS.]
For the estimation of nitrogen in nitro-cellulose take .5 to .65 grm., and
place in the decomposition flask f (Fig. 45), washing in with about 25 c.c.
of water by alternately opening clips D and E. The air in the flask is driven
out by boiling, whilst the air is shut off by the tube i dipping into the basin
W, which is filled with the soda lye, and tube K is placed in the test tube R,
which contains a few c.c. of water. As soon as all the air is completely
driven out, clips D and E are closed, and the gas jet is taken away. (This
flask must be a strong one, or it will burst.) Into test tube R, 25 c.c. of
concentrated solution of protochloride of iron and 10 to 15 c.c. concentrated
hydrochloric acid are poured, which are sucked up into the developing flask
f by opening clip E, air being carefully kept from entering. The clip E is
now closed, and tube i is put underneath the burette, and the development of
NO gas is commenced by heating the contents of the flask f. When the
pressure of the gas in the flask has become greater than the pressure of the
atmosphere, the connecting tube begins to swell at i, whereupon clip D is
opened, and the boiling continued with frequent shaking of the bulb, until
no more nitrous gas bubbles rise up into the soda lye, the distilling over of
the HCl causes a crackling noise, the clip D is closed, and E opened. The
burette is again put hermetically on the indiarubber stopper in basin W, and
the apparatus is left to cool until the water discharged through P shows the
same temperature as the water flowing through (into the cooling jacket) Z.
If the level of the soda solution in the tube X is now put on exactly the same
level as that in the burette by lowering or elevating the tube X as required,
Page 241
the volume of NO obtained in c.c. can be read off within 1/10 c.c., and the
percentage of nitrogen calculated by the usual formula.
[Illustration: FIG. 45.—Decomposition Flask for Schultze-Tieman
Method.]
The solution of protochloride of iron is obtained by dissolving iron nails,
&c., in concentrated HCl, the iron being in excess. When the development
of hydrogen ceases, it is necessary to filter warm through a paper filter, and
acidify filtrate with a few drops of HCl. The soda solution used has a sp. gr.
of 1.210 to 1.260; equals 25° to 30° B. The nitro-cellulose is dried in
quantities of 2 grms. at 70° C. during eight to ten hours, and then three
hours in an exiccator over H_{2}SO_{4}. The results obtained with this
apparatus are very accurate. The reaction is founded upon that of MM.
Champion and Pellet's method.
~The Kjeldahl Method of Determining Nitrogen.~—This method, which
has been so largely used by analysts for the determination of nitrogen in
organic bodies, more especially perhaps in manures, was proposed by J.
Kjeldahl,[A] of the Carlsberg Laboratory of Copenhagen. It was afterwards
modified by Jodlbauer, of Munich,[B] and applied to the analysis of nitro-
explosives by M. Chenel, of the Laboratoire Centrale des Poudres, whose
method of procedure is as follows:—0.5 grm. of the finely powdered
substance is digested in the cold with a solution of 1.2 grm. of phenol and
0.4 grm. phosphoric anhydride in 30 c.c. of sulphuric acid. The mixture is
kept well shaken until the solution is complete. From 3 to 4 grms. of zinc-
dust is then cautiously and gradually added, the temperature of the mass
being kept down until complete reduction has been effected. Finally, 0.7
grm. of mercury is added, and the process continued in the usual way,
according to Kjeldahl; that is, the liquid is distilled until all the ammonia
percentage of nitrogen calculated by the usual formula.
[Illustration: FIG. 45.—Decomposition Flask for Schultze-Tieman
Method.]
The solution of protochloride of iron is obtained by dissolving iron nails,
&c., in concentrated HCl, the iron being in excess. When the development
of hydrogen ceases, it is necessary to filter warm through a paper filter, and
acidify filtrate with a few drops of HCl. The soda solution used has a sp. gr.
of 1.210 to 1.260; equals 25° to 30° B. The nitro-cellulose is dried in
quantities of 2 grms. at 70° C. during eight to ten hours, and then three
hours in an exiccator over H_{2}SO_{4}. The results obtained with this
apparatus are very accurate. The reaction is founded upon that of MM.
Champion and Pellet's method.
~The Kjeldahl Method of Determining Nitrogen.~—This method, which
has been so largely used by analysts for the determination of nitrogen in
organic bodies, more especially perhaps in manures, was proposed by J.
Kjeldahl,[A] of the Carlsberg Laboratory of Copenhagen. It was afterwards
modified by Jodlbauer, of Munich,[B] and applied to the analysis of nitro-
explosives by M. Chenel, of the Laboratoire Centrale des Poudres, whose
method of procedure is as follows:—0.5 grm. of the finely powdered
substance is digested in the cold with a solution of 1.2 grm. of phenol and
0.4 grm. phosphoric anhydride in 30 c.c. of sulphuric acid. The mixture is
kept well shaken until the solution is complete. From 3 to 4 grms. of zinc-
dust is then cautiously and gradually added, the temperature of the mass
being kept down until complete reduction has been effected. Finally, 0.7
grm. of mercury is added, and the process continued in the usual way,
according to Kjeldahl; that is, the liquid is distilled until all the ammonia
Page 242
has passed over, and is absorbed in the standard acid. The distillate is then
titrated with standard ammonia.
[Footnote A: J. Kjeldahl, Zeitschrift Anal. Chem., 1883, xxii., p. 366.]
[Footnote B: Jodlbauer, Chemisches Centralblatt, 1886, pp. 434-484. See
also Arms and Explosives, 1893, p. 87.]
The NO_{2} group is at the moment of solution fixed upon the phenol
with the production of mono-nitro-phenol, which is afterwards reduced by
the action of the zinc-dust into the amido derivative. During the subsequent
combustion, the nitrogen of the amido-phenol becomes fixed in the state of
ammonia. M. Chenel is perfectly satisfied with the results obtained, but he
points out that the success of the operation depends upon the complete
conversion of the phenol into the mono-nitro derivatives. This takes place
whenever the organic compound forms a clear solution in the cold
sulphuric acid mixture. Substances like collodion or gun-cotton must be
very finely divided for successful treatment. The following table shows
some of the results obtained by M. Chenel:—
______________________________________________ | | | | | Total
Nitrogen. | | Substances Analysed. |______________________| | | | | | |
Calculated. | Found. | | |_____________|________| | | | | | Saltpetre
(KNO_{3}) | 13.86 | 13.91 | | | | 13.82 | | | | 13.73 | | | | 13.96 | | Ammonium
nitrate | 35.00 | 35.31 | | | | 34.90 | | | | 34.96 | | Barium nitrate | 10.72 | 10.67 |
| | | 10.62 | | Nitro-glycerol | 18.50 | 18.45 | | Di-nitro-benzol[A] | 16.67 |
16.78 | | | | 16.57 | | Para-nitro-phenol | 10.07 | 10.03 | | Picric acid[A] | 18.34
| 18.42 | | | | 18.43 | | Ammonium picrate | 22.76 | 22.63 | | | | 22.67 | | Di-
nitro-ortho-cresol | 14.14 | 14.10 | | | | 13.98 | | Tri-nitro-meta-cresol | 17.28 |
17.57 | | | | 17.27 | |_______________________|_____________|________|
titrated with standard ammonia.
[Footnote A: J. Kjeldahl, Zeitschrift Anal. Chem., 1883, xxii., p. 366.]
[Footnote B: Jodlbauer, Chemisches Centralblatt, 1886, pp. 434-484. See
also Arms and Explosives, 1893, p. 87.]
The NO_{2} group is at the moment of solution fixed upon the phenol
with the production of mono-nitro-phenol, which is afterwards reduced by
the action of the zinc-dust into the amido derivative. During the subsequent
combustion, the nitrogen of the amido-phenol becomes fixed in the state of
ammonia. M. Chenel is perfectly satisfied with the results obtained, but he
points out that the success of the operation depends upon the complete
conversion of the phenol into the mono-nitro derivatives. This takes place
whenever the organic compound forms a clear solution in the cold
sulphuric acid mixture. Substances like collodion or gun-cotton must be
very finely divided for successful treatment. The following table shows
some of the results obtained by M. Chenel:—
______________________________________________ | | | | | Total
Nitrogen. | | Substances Analysed. |______________________| | | | | | |
Calculated. | Found. | | |_____________|________| | | | | | Saltpetre
(KNO_{3}) | 13.86 | 13.91 | | | | 13.82 | | | | 13.73 | | | | 13.96 | | Ammonium
nitrate | 35.00 | 35.31 | | | | 34.90 | | | | 34.96 | | Barium nitrate | 10.72 | 10.67 |
| | | 10.62 | | Nitro-glycerol | 18.50 | 18.45 | | Di-nitro-benzol[A] | 16.67 |
16.78 | | | | 16.57 | | Para-nitro-phenol | 10.07 | 10.03 | | Picric acid[A] | 18.34
| 18.42 | | | | 18.43 | | Ammonium picrate | 22.76 | 22.63 | | | | 22.67 | | Di-
nitro-ortho-cresol | 14.14 | 14.10 | | | | 13.98 | | Tri-nitro-meta-cresol | 17.28 |
17.57 | | | | 17.27 | |_______________________|_____________|________|
Page 243
[Footnote A: Dr. Bernard Dyer obtained 18.39 per cent. for picric acid
and 16.54 per cent. for di-nitro-benzol.—Jour. Chem. Soc., Aug. 1895.]
When Chenel endeavoured to apply Jodlbauer's modification of
Kjeldahl's process to the examination of the tri- and tetra-nitrated
naphthalenes, he found that good results were not obtainable, because these
compounds do not dissolve completely in the cold sulphuric acid. It may,
however, be used if they are previously converted into the naphthylamines,
according to the plan proposed by D'Aguiar and Lautemann (Bull. Soc.
Chim., vol. iii., new series, p. 256). This is rapidly effected as follows:—
Twelve grms. of iodine are gradually added to a solution of 2 grms. of
phosphorus in about 15 or 20 c.c. of bisulphide of carbon, this solution
being contained in a flask of 250 c.c. capacity. The flask and its contents are
heated on the water bath at 100° C. with constant attention, until the last
traces of the carbon bisulphide have distilled away. It is then cooled, and the
iodide of phosphorus is detached from the sides of the flask by shaking, but
not expelled. The next step is to add about 0.5 to 0.6 grm. of the substance
that is to be analysed, after which 8 grms. of water are introduced, and the
flask is agitated gently two or three times. As soon as the reaction becomes
lively, the contents of the flask are well shaken. It is usually finished about
one minute after the addition of the water. The flask is now cooled, and 25
c.c. of sulphuric acid, together with 0.7 grm. of mercury, are gradually
added; hydriodic acid (HI) forms, and the temperature of the flask must be
raised sufficiently to expel it. The remaining part of the operation is as in
the ordinary Kjeldahl process.
M. Chenel has found this process the best for the analysis of the nitro-
naphthalenes, and for impervious substances like collodion or gun-cotton.
Personally, I have never been able to obtain satisfactory results with this
process in the analysis of nitro-cellulose, and I am of opinion that the
and 16.54 per cent. for di-nitro-benzol.—Jour. Chem. Soc., Aug. 1895.]
When Chenel endeavoured to apply Jodlbauer's modification of
Kjeldahl's process to the examination of the tri- and tetra-nitrated
naphthalenes, he found that good results were not obtainable, because these
compounds do not dissolve completely in the cold sulphuric acid. It may,
however, be used if they are previously converted into the naphthylamines,
according to the plan proposed by D'Aguiar and Lautemann (Bull. Soc.
Chim., vol. iii., new series, p. 256). This is rapidly effected as follows:—
Twelve grms. of iodine are gradually added to a solution of 2 grms. of
phosphorus in about 15 or 20 c.c. of bisulphide of carbon, this solution
being contained in a flask of 250 c.c. capacity. The flask and its contents are
heated on the water bath at 100° C. with constant attention, until the last
traces of the carbon bisulphide have distilled away. It is then cooled, and the
iodide of phosphorus is detached from the sides of the flask by shaking, but
not expelled. The next step is to add about 0.5 to 0.6 grm. of the substance
that is to be analysed, after which 8 grms. of water are introduced, and the
flask is agitated gently two or three times. As soon as the reaction becomes
lively, the contents of the flask are well shaken. It is usually finished about
one minute after the addition of the water. The flask is now cooled, and 25
c.c. of sulphuric acid, together with 0.7 grm. of mercury, are gradually
added; hydriodic acid (HI) forms, and the temperature of the flask must be
raised sufficiently to expel it. The remaining part of the operation is as in
the ordinary Kjeldahl process.
M. Chenel has found this process the best for the analysis of the nitro-
naphthalenes, and for impervious substances like collodion or gun-cotton.
Personally, I have never been able to obtain satisfactory results with this
process in the analysis of nitro-cellulose, and I am of opinion that the
Page 244
process does not possess any advantage over the nitrometer method, at any
rate for the analysis of gun-cotton.
Table giving the Percentages of Nitrogen and Oxide of Nitrogen in
Various
Substances used in or as Explosives:
Name FORMULÆ NITROGEN NO_{2}
per cent. per cent.
Nitroglycerine C_{3}H_{5}(ONO_{2}){3} 18.50 = 60.70
Hexa-nitro-cellulose C{12}H_{14}O_{4}(ONO_{2}){6} 14.14 = 46.42
Penta-nitro-cellulose C{6}H_{8}O_{5}(ONO_{2}){5} 11.11 = 36.50
Nitro-benzene C{6}H_{5}NO_{2} 11.38 = 37.39
Di-nitro-benzene C_{6}H_{4}(NO_{2}){2} 16.67 = 54.77
Tri-nitro-benzene C{6}H_{3}(NO_{2}){3} 19.24 = 63.22
Nitro-toluene C{7}H_{7}NO_{2} 10.21 = 33.49
Nitro-naphthalene C_{10}H_{7}NO_{2} 8.09 = 26.53
Di-nitro-naphthalene C_{10}H_{6}(NO_{2}){2} 12.84 = 42.12
Nitro-mannite C{6}H_{7}(NO_{3}){6} 23.59 = 77.37
Nitro-starch C{6}H_{8}O_{4}(HNO_{3}) 6.76 = 22.18
Picric acid
(Tri-nitro-phenol) C_{6}H_{2}OH(NO_{2}){3} 18.34 = 60.15
Chloro-nitro-benzene C{6}H_{3}Cl(NO_{2}){2} 13.82 = 45.43
Ammonium nitrate NH{4}NO_{3} 35.00 =
Sodium nitrate NaNO_{3} 16.47 =
Potassium nitrate KNO_{3} 13.86 =
Nitric acid HNO_{3} 22.22 =
Barium nitrate Ba(NO_{3})_{2} 10.72 =
~Analysis of Celluloid.~—The finely divided celluloid is well stirred, by
means of a platinum wire, with concentrated sulphuric acid in the cup of a
rate for the analysis of gun-cotton.
Table giving the Percentages of Nitrogen and Oxide of Nitrogen in
Various
Substances used in or as Explosives:
Name FORMULÆ NITROGEN NO_{2}
per cent. per cent.
Nitroglycerine C_{3}H_{5}(ONO_{2}){3} 18.50 = 60.70
Hexa-nitro-cellulose C{12}H_{14}O_{4}(ONO_{2}){6} 14.14 = 46.42
Penta-nitro-cellulose C{6}H_{8}O_{5}(ONO_{2}){5} 11.11 = 36.50
Nitro-benzene C{6}H_{5}NO_{2} 11.38 = 37.39
Di-nitro-benzene C_{6}H_{4}(NO_{2}){2} 16.67 = 54.77
Tri-nitro-benzene C{6}H_{3}(NO_{2}){3} 19.24 = 63.22
Nitro-toluene C{7}H_{7}NO_{2} 10.21 = 33.49
Nitro-naphthalene C_{10}H_{7}NO_{2} 8.09 = 26.53
Di-nitro-naphthalene C_{10}H_{6}(NO_{2}){2} 12.84 = 42.12
Nitro-mannite C{6}H_{7}(NO_{3}){6} 23.59 = 77.37
Nitro-starch C{6}H_{8}O_{4}(HNO_{3}) 6.76 = 22.18
Picric acid
(Tri-nitro-phenol) C_{6}H_{2}OH(NO_{2}){3} 18.34 = 60.15
Chloro-nitro-benzene C{6}H_{3}Cl(NO_{2}){2} 13.82 = 45.43
Ammonium nitrate NH{4}NO_{3} 35.00 =
Sodium nitrate NaNO_{3} 16.47 =
Potassium nitrate KNO_{3} 13.86 =
Nitric acid HNO_{3} 22.22 =
Barium nitrate Ba(NO_{3})_{2} 10.72 =
~Analysis of Celluloid.~—The finely divided celluloid is well stirred, by
means of a platinum wire, with concentrated sulphuric acid in the cup of a
Page 245
Lungé nitrometer, and when dissolved the nitrogen determined in the
solution in the usual way. To prevent interference from camphor, the
following treatment is suggested by H. Zaunschirm (Chem. Zeit., xiv., 905).
Dissolve a weighed quantity of the celluloid in a mixture of ether- alcohol,
mixed with a weighed quantity of washed and ignited asbestos, or pumice-
stone, dry, and disintegrate the mass, and afterwards extract the camphor
with chloroform, dry, and weigh: then extract with absolute methyl-alcohol,
evaporate, weigh, and examine the nitro-cellulose in the nitrometer.
~Picric Acid and Picrates.~—Picric acid is soluble in hot water, and to
the extent of 1 part in 100 in cold water, also in ether, chloroform,
glycerine, 10 per cent. soda solution, alcohol, amylic alcohol, carbon
bisulphide, benzene, and petroleum. If a solution of picric acid be boiled
with a strong solution of potassium cyanide, a deep red liquid is produced,
owing to the formation of potassium iso-purpurate, which crystallises in
small reddish-brown plates with a beetle-green lustre. This, by reaction with
ammonium chloride, gives ammonium iso-purpurate
(NH_{4}C_{8}H_{4}N_{5}O_{6}), or artificial murexide, which dies silk
and wool a beautiful red colour. On adding barium chloride to either of the
above salts, a vermilion-red precipitate was formed, consisting of barium
iso-purpurate. With ammonio-sulphate of copper, solutions of picric acid
give a bright green precipitate. Mr A.H. Allen gives the following methods
for the assay of commercial picric acid, in his "Commercial Organic
Analysis":—
~Resinous and Tarry matters~ are not unfrequently present. They are left
insoluble on dissolving the sample in boiling water. The separation is more
perfect if the hot solution be exactly neutralised by caustic soda.
~Sulphuric Acid, Hydrochloric Acid, and Oxalic Acid~, and their salts
are detected by adding to the filtered aqueous solution of the sample
solution in the usual way. To prevent interference from camphor, the
following treatment is suggested by H. Zaunschirm (Chem. Zeit., xiv., 905).
Dissolve a weighed quantity of the celluloid in a mixture of ether- alcohol,
mixed with a weighed quantity of washed and ignited asbestos, or pumice-
stone, dry, and disintegrate the mass, and afterwards extract the camphor
with chloroform, dry, and weigh: then extract with absolute methyl-alcohol,
evaporate, weigh, and examine the nitro-cellulose in the nitrometer.
~Picric Acid and Picrates.~—Picric acid is soluble in hot water, and to
the extent of 1 part in 100 in cold water, also in ether, chloroform,
glycerine, 10 per cent. soda solution, alcohol, amylic alcohol, carbon
bisulphide, benzene, and petroleum. If a solution of picric acid be boiled
with a strong solution of potassium cyanide, a deep red liquid is produced,
owing to the formation of potassium iso-purpurate, which crystallises in
small reddish-brown plates with a beetle-green lustre. This, by reaction with
ammonium chloride, gives ammonium iso-purpurate
(NH_{4}C_{8}H_{4}N_{5}O_{6}), or artificial murexide, which dies silk
and wool a beautiful red colour. On adding barium chloride to either of the
above salts, a vermilion-red precipitate was formed, consisting of barium
iso-purpurate. With ammonio-sulphate of copper, solutions of picric acid
give a bright green precipitate. Mr A.H. Allen gives the following methods
for the assay of commercial picric acid, in his "Commercial Organic
Analysis":—
~Resinous and Tarry matters~ are not unfrequently present. They are left
insoluble on dissolving the sample in boiling water. The separation is more
perfect if the hot solution be exactly neutralised by caustic soda.
~Sulphuric Acid, Hydrochloric Acid, and Oxalic Acid~, and their salts
are detected by adding to the filtered aqueous solution of the sample
Page 246
solutions of the picrates of barium, silver, and calcium. These salts are
readily made by boiling picric acid with the carbonates of the respective
metals and filtering: other soluble salts of these methods may be substituted
for the picrates, but they are less satisfactory.
~Nitric Acid~ may be detected by the red fumes evolved on warming the
sample with copper turnings.
~Inorganic Impurities and Picrates of Potash and Sodium~, &c., leave
residues on cautious ignition.
~General Impurities and Adulterations~ may be detected and determined
by shaking 1 grm. of the sample of acid in a graduated tube with 25 c.c. of
ether, the pure acid dissolves, while any oxalic acid, nitrates, picrates, boric
acid, alum, sugar, &c., will be left insoluble, and after removal of the
ethereal liquid, may be readily identified and determined. For the detection
and determination of water and of oxalic acid, 50 c.c. of warm benzene may
be advantageously substituted for ether. Sugar may be separated from the
other impurities by treating the residue insoluble in ether or benzene with
rectified spirit, in which sugar and boric acid alone will dissolve. If boric
acid be present, the alcoholic solution will burn with a green flame. Mono-
and di-nitrophenic acids lower the melting point (122° C). Their calcium
salts are less soluble than the picrate, and may be approximately separated
from it by fractional crystallisation, or by precipitating the hot saturated
solution of the sample with excess of lime water. Picric acid may be
determined by extracting the acidulated aqueous solution by agitation with
ether or benzene, and subsequently removing and evaporating off the
solvent. It may also be precipitated as the potassium salt.
~Potassium Picrate~ [KC_{6}H_{2}(NO_{2})_{3}O]. When a strong
solution of picric acid is neutralised by carbonate of potash, this salt is
readily made by boiling picric acid with the carbonates of the respective
metals and filtering: other soluble salts of these methods may be substituted
for the picrates, but they are less satisfactory.
~Nitric Acid~ may be detected by the red fumes evolved on warming the
sample with copper turnings.
~Inorganic Impurities and Picrates of Potash and Sodium~, &c., leave
residues on cautious ignition.
~General Impurities and Adulterations~ may be detected and determined
by shaking 1 grm. of the sample of acid in a graduated tube with 25 c.c. of
ether, the pure acid dissolves, while any oxalic acid, nitrates, picrates, boric
acid, alum, sugar, &c., will be left insoluble, and after removal of the
ethereal liquid, may be readily identified and determined. For the detection
and determination of water and of oxalic acid, 50 c.c. of warm benzene may
be advantageously substituted for ether. Sugar may be separated from the
other impurities by treating the residue insoluble in ether or benzene with
rectified spirit, in which sugar and boric acid alone will dissolve. If boric
acid be present, the alcoholic solution will burn with a green flame. Mono-
and di-nitrophenic acids lower the melting point (122° C). Their calcium
salts are less soluble than the picrate, and may be approximately separated
from it by fractional crystallisation, or by precipitating the hot saturated
solution of the sample with excess of lime water. Picric acid may be
determined by extracting the acidulated aqueous solution by agitation with
ether or benzene, and subsequently removing and evaporating off the
solvent. It may also be precipitated as the potassium salt.
~Potassium Picrate~ [KC_{6}H_{2}(NO_{2})_{3}O]. When a strong
solution of picric acid is neutralised by carbonate of potash, this salt is
Page 247
thrown down in yellow crystalline needles, which require 260 parts of cold
or 14 parts of hot water for their solution. In alcohol it is much less soluble.
~Ammonium Picrate~ is more soluble in water than the above, and
sodium picrate is readily soluble in water, but nearly insoluble in solution of
sodium carbonate.
~Picrates of the Alkaloids.~—Picric acid forms insoluble salts with many
of the alkaloids, and picric acid may be determined in the following
manner:—To the solution of picric acid, or a picrate, add a solution of
sulphate of cinchonine acidulated with H_{2}SO_{4}. The precipitated
picrate of cinchonine
[C_{20}H_{24}N_{2}O(C_{6}H_{2}N_{3}O_{7})_{2}] is washed with
cold water, rinsed off the filter into a porcelain crucible or dish, the water
evaporated on the water bath, and the residual salt weighed. Its weight,
multiplied by .6123, gives the quantity of picric acid in the sample taken.
~Analysis of Glycerine.~[A] Glycerine that is to be used for the
manufacture of nitro-glycerine should have a minimum specific gravity of
1.261 at 15° C. This can be determined, either by the aid of a Sartorius
specific gravity balance, or by using an ordinary specific gravity bottle. One
of 10 or 25 c.c. capacity is very convenient.
[Footnote A: See also Sulman and Berry, Analyst, xi., 12-34, and Allen's
"Commercial Organic Analysis," vol. ii., part i.]
~Residue~[A] left upon evaporation should not be more than 0.25 per
cent. To determine this, take 25 grms. of the glycerine, and evaporate it at a
temperature of about 160° C. in a platinum basin, and finish in an air bath.
Weigh until constant weight is obtained. Afterwards incinerate over a
bunsen burner, and weigh the ash.
or 14 parts of hot water for their solution. In alcohol it is much less soluble.
~Ammonium Picrate~ is more soluble in water than the above, and
sodium picrate is readily soluble in water, but nearly insoluble in solution of
sodium carbonate.
~Picrates of the Alkaloids.~—Picric acid forms insoluble salts with many
of the alkaloids, and picric acid may be determined in the following
manner:—To the solution of picric acid, or a picrate, add a solution of
sulphate of cinchonine acidulated with H_{2}SO_{4}. The precipitated
picrate of cinchonine
[C_{20}H_{24}N_{2}O(C_{6}H_{2}N_{3}O_{7})_{2}] is washed with
cold water, rinsed off the filter into a porcelain crucible or dish, the water
evaporated on the water bath, and the residual salt weighed. Its weight,
multiplied by .6123, gives the quantity of picric acid in the sample taken.
~Analysis of Glycerine.~[A] Glycerine that is to be used for the
manufacture of nitro-glycerine should have a minimum specific gravity of
1.261 at 15° C. This can be determined, either by the aid of a Sartorius
specific gravity balance, or by using an ordinary specific gravity bottle. One
of 10 or 25 c.c. capacity is very convenient.
[Footnote A: See also Sulman and Berry, Analyst, xi., 12-34, and Allen's
"Commercial Organic Analysis," vol. ii., part i.]
~Residue~[A] left upon evaporation should not be more than 0.25 per
cent. To determine this, take 25 grms. of the glycerine, and evaporate it at a
temperature of about 160° C. in a platinum basin, and finish in an air bath.
Weigh until constant weight is obtained. Afterwards incinerate over a
bunsen burner, and weigh the ash.
Page 248
[Footnote A: Organic matter up to .6 per cent. is not always prejudicial to
the nitrating quantities of a glycerine.]
~Silver Test.~ A portion of the sample of glycerine to be tested should be
put in a small weighing bottle, and a quarter of its bulk of N/10 silver
nitrate solution added to it, then shake it, and place in a dark cupboard for
fifteen minutes. It must be pronounced bad if it becomes black or dark
brown within that time (acrolein, formic, and butyric acids).
The German official test for glycerine for pharmaceutical purposes is
much more stringent, 1 c.c. of glycerine heated to boiling with 1 c.c. of
ammonia solution and three drops of silver nitrate solution must give
neither colour or precipitate within five minutes.
~Nitration.~ Fifty grms. of the glycerine are poured from a beaker into a
mixture of concentrated nitric acid (specific gravity 1.53) and sulphuric acid
(1.84), mixed in the proportions of 3 HNO_{3} to 5 H_{2}SO_{4} (about
400 c.c. of mixed acids). The mixed acids should be put into a rather large
beaker, and held in the right hand in a basin of water, and the glycerine
slowly poured into them from a smaller one held in the left. A constant
rotatory motion should be given to the beaker in which the nitration is
performed. When all the glycerine has been added, and the mixture has
been shaken for a few minutes longer, it is poured into a separator, and
allowed to stand for some time. It should, if the glycerine is a good one,
have separated from the mixed acids in ten minutes, and the line of
demarcation between the nitro-glycerine and the acid should be clear and
sharp, neither should there be any white flocculent matter suspended in the
liquid. The excess of acids is now drawn off, and the nitro-glycerine shaken
once or twice with a warm solution of carbonate of soda, and afterwards
with water alone. The nitro-glycerine is then drawn off into a weighed
beaker, the surface dried with a piece of filter paper, and weighed; 100 parts
the nitrating quantities of a glycerine.]
~Silver Test.~ A portion of the sample of glycerine to be tested should be
put in a small weighing bottle, and a quarter of its bulk of N/10 silver
nitrate solution added to it, then shake it, and place in a dark cupboard for
fifteen minutes. It must be pronounced bad if it becomes black or dark
brown within that time (acrolein, formic, and butyric acids).
The German official test for glycerine for pharmaceutical purposes is
much more stringent, 1 c.c. of glycerine heated to boiling with 1 c.c. of
ammonia solution and three drops of silver nitrate solution must give
neither colour or precipitate within five minutes.
~Nitration.~ Fifty grms. of the glycerine are poured from a beaker into a
mixture of concentrated nitric acid (specific gravity 1.53) and sulphuric acid
(1.84), mixed in the proportions of 3 HNO_{3} to 5 H_{2}SO_{4} (about
400 c.c. of mixed acids). The mixed acids should be put into a rather large
beaker, and held in the right hand in a basin of water, and the glycerine
slowly poured into them from a smaller one held in the left. A constant
rotatory motion should be given to the beaker in which the nitration is
performed. When all the glycerine has been added, and the mixture has
been shaken for a few minutes longer, it is poured into a separator, and
allowed to stand for some time. It should, if the glycerine is a good one,
have separated from the mixed acids in ten minutes, and the line of
demarcation between the nitro-glycerine and the acid should be clear and
sharp, neither should there be any white flocculent matter suspended in the
liquid. The excess of acids is now drawn off, and the nitro-glycerine shaken
once or twice with a warm solution of carbonate of soda, and afterwards
with water alone. The nitro-glycerine is then drawn off into a weighed
beaker, the surface dried with a piece of filter paper, and weighed; 100 parts
Page 249
of a good glycerine should yield about 230 of nitro-glycerine. A quicker
method is to take only 10 c.c. of the glycerine, of which the specific gravity
is already known, nitrate as before, and pour into a burette, read off the
volume of nitro-glycerine in c.c. and multiply them by 1.6 (the specific
gravity of nitro-glycerine), thus: 10 grms. gave 14.5 c.c. nitro-glycerine,
and 14.5 x 1.6 = 23.2 grms., therefore 100 would give 232 grms. nitro-
glycerine. The points to be noted in the nitration of a sample of glycerine
are: the separation should be sharp, and within half an hour or less, and
there should be no white flocculent matter formed, especially when the
carbonate of soda solution is added.
~Total Acid Equivalent.~ Mr G.E. Barton (Jour. Amer. Chem. Soc., 1895)
proposes to determine thus: 100 c.c. of glycerine are diluted to 300 c.c. in a
beaker, a few drops of a 1 per cent. solution of phenolphthalein and 10 c.c.
of normal caustic soda solution are added; after boiling, the liquid is titrated
with normal hydrochloric acid (fatty acids are thus indicated and roughly
determined).
~Neutrality.~ The same chemist determines the neutrality of glycerine
thus: 50 c.c. of glycerine mixed with 100 c.c. of water and a few drops of
alcoholic phenolphthalein[A] are titrated with hydrochloric acid or sodium
hydroxide; not more than 0.3 c.c. normal hydrochloric acid or normal soda
solution should be required to render the sample neutral; raw glycerines
contain from .5 to 1.0 per cent. of sodium carbonate.
[Footnote A: Sulman and Berry prefer litmus as indicator.]
~Determination of Free Fatty Acids.~ A weighed quantity of the
glycerine is shaken up with some neutral ether in a separating funnel, the
glycerine allowed to settle, drawn off, and the ether washed with three
separate lots of water. The water must have been recently boiled, and be
quite free from CO_{2}. All the free fatty acid is now in the ether, and no
method is to take only 10 c.c. of the glycerine, of which the specific gravity
is already known, nitrate as before, and pour into a burette, read off the
volume of nitro-glycerine in c.c. and multiply them by 1.6 (the specific
gravity of nitro-glycerine), thus: 10 grms. gave 14.5 c.c. nitro-glycerine,
and 14.5 x 1.6 = 23.2 grms., therefore 100 would give 232 grms. nitro-
glycerine. The points to be noted in the nitration of a sample of glycerine
are: the separation should be sharp, and within half an hour or less, and
there should be no white flocculent matter formed, especially when the
carbonate of soda solution is added.
~Total Acid Equivalent.~ Mr G.E. Barton (Jour. Amer. Chem. Soc., 1895)
proposes to determine thus: 100 c.c. of glycerine are diluted to 300 c.c. in a
beaker, a few drops of a 1 per cent. solution of phenolphthalein and 10 c.c.
of normal caustic soda solution are added; after boiling, the liquid is titrated
with normal hydrochloric acid (fatty acids are thus indicated and roughly
determined).
~Neutrality.~ The same chemist determines the neutrality of glycerine
thus: 50 c.c. of glycerine mixed with 100 c.c. of water and a few drops of
alcoholic phenolphthalein[A] are titrated with hydrochloric acid or sodium
hydroxide; not more than 0.3 c.c. normal hydrochloric acid or normal soda
solution should be required to render the sample neutral; raw glycerines
contain from .5 to 1.0 per cent. of sodium carbonate.
[Footnote A: Sulman and Berry prefer litmus as indicator.]
~Determination of Free Fatty Acids.~ A weighed quantity of the
glycerine is shaken up with some neutral ether in a separating funnel, the
glycerine allowed to settle, drawn off, and the ether washed with three
separate lots of water. The water must have been recently boiled, and be
quite free from CO_{2}. All the free fatty acid is now in the ether, and no
Page 250
other soluble acid. A drop of phenolphthalein is now added, a little water,
and the acidity determined by titration with deci-normal baryta solution,
and the baryta solution taken calculated as oleic acid.
~Combined Fatty Acid.~ About 30 grms. of the glycerine are placed in a
flask, and to it is added about half a grm. of caustic soda in solution. The
mixture is heated for ten minutes at 150° C. After cooling some pure ether
is added to it, and enough dilute H_{2}SO_{4} to render it distinctly acid.
It is well shaken. All the fatty acids go into the ether. The aqueous solution
is then removed, and the ether well washed to remove all H_{2}SO_{4}.
After the addition of phenolphthalein the acid is titrated, and the amount
used calculated into oleic acid. From this total amount of fatty acids the free
fatty acid is deducted, and the quantity of combined fatty acids thus
obtained.
~Impurities.~ The following impurities may be found in bad samples of
glycerine:—Lead, arsenic, lime, chlorine, sulphuric acid, thio-sulphates,
sulphides, cyanogen compounds, organic acids (especially oleic acid and
fatty acids[A]), rosin products, and other organic bodies. It is also said to be
adulterated with sugar and glucose dextrine. Traces of sulphuric acid and
arsenic may be allowed, also very small traces indeed of lime and chlorine.
[Footnote A: These substances often cause trouble in nitrating, white
flocculent matter being formed during the process of washing.]
The organic acids, formic and butyric acids may be detected by heating a
sample of the glycerine in a test tube with alcohol and sulphuric acid, when,
if present, compound ethers, such as ethylic formate and butyrate, the
former smelling like peaches and the latter of pine-apple, will be formed.
~Oleic Acid~, if present in large quantity, will come down upon diluting
the sample with water, but smaller quantities may be detected by passing a
and the acidity determined by titration with deci-normal baryta solution,
and the baryta solution taken calculated as oleic acid.
~Combined Fatty Acid.~ About 30 grms. of the glycerine are placed in a
flask, and to it is added about half a grm. of caustic soda in solution. The
mixture is heated for ten minutes at 150° C. After cooling some pure ether
is added to it, and enough dilute H_{2}SO_{4} to render it distinctly acid.
It is well shaken. All the fatty acids go into the ether. The aqueous solution
is then removed, and the ether well washed to remove all H_{2}SO_{4}.
After the addition of phenolphthalein the acid is titrated, and the amount
used calculated into oleic acid. From this total amount of fatty acids the free
fatty acid is deducted, and the quantity of combined fatty acids thus
obtained.
~Impurities.~ The following impurities may be found in bad samples of
glycerine:—Lead, arsenic, lime, chlorine, sulphuric acid, thio-sulphates,
sulphides, cyanogen compounds, organic acids (especially oleic acid and
fatty acids[A]), rosin products, and other organic bodies. It is also said to be
adulterated with sugar and glucose dextrine. Traces of sulphuric acid and
arsenic may be allowed, also very small traces indeed of lime and chlorine.
[Footnote A: These substances often cause trouble in nitrating, white
flocculent matter being formed during the process of washing.]
The organic acids, formic and butyric acids may be detected by heating a
sample of the glycerine in a test tube with alcohol and sulphuric acid, when,
if present, compound ethers, such as ethylic formate and butyrate, the
former smelling like peaches and the latter of pine-apple, will be formed.
~Oleic Acid~, if present in large quantity, will come down upon diluting
the sample with water, but smaller quantities may be detected by passing a
Page 251
current of nitrogen peroxide, N_{2}O_{4} (obtained by heating lead
nitrate), through the diluted sample, when a white flocculent precipitate of
elaidic acid, which is less soluble than oleic acid, will be thrown down. By
agitating glycerol with chloroform, fatty acids, rosin oil, and some other
impurities are dissolved, while certain others form a turbid layer between
the chloroform and the supernatant liquid. On separating the chloroform
and evaporating it to dryness, a residue is obtained which may be further
examined.
~Sodium Chloride~ can be determined in 100 c.c. of the glycerine by
adding a little water, neutralised with sodium carbonate, and then titrated
with a deci-normal solution of silver nitrate, using potassium chromate as
indicator.
~Organic Impurities~ of various kinds occur in crude glycerine, and are
mostly objectionable. Their sum may be determined with fair accuracy by
Sulman and Berry's method: 50 grms. of the sample are diluted with twice
its measure of water, carefully neutralised with acetic acid, and warmed to
expel carbonic acid; when cold, a solution of basic lead acetate is added in
slight but distinct excess, and the mixture well agitated. The formation of an
abundant precipitate, which rapidly subsides, is an indication of
considerable impurity in the sample. To ascertain its amount, the precipitate
is first washed by decantation, and then collected on a tared, or preferably a
double counter-poised filter, where it is further washed, dried at 100° to
105° C., and weighed. The precipitate and filter paper are then ignited
separately in porcelain, at a low red heat, the residues moistened with a few
drops of nitric acid and reignited; the weight of the lead oxide deducted
from that of the original precipitate gives the weight of the organic matter
precipitated by the lead. Raw glycerines contain from 0.5 to 1.0 per cent.
nitrate), through the diluted sample, when a white flocculent precipitate of
elaidic acid, which is less soluble than oleic acid, will be thrown down. By
agitating glycerol with chloroform, fatty acids, rosin oil, and some other
impurities are dissolved, while certain others form a turbid layer between
the chloroform and the supernatant liquid. On separating the chloroform
and evaporating it to dryness, a residue is obtained which may be further
examined.
~Sodium Chloride~ can be determined in 100 c.c. of the glycerine by
adding a little water, neutralised with sodium carbonate, and then titrated
with a deci-normal solution of silver nitrate, using potassium chromate as
indicator.
~Organic Impurities~ of various kinds occur in crude glycerine, and are
mostly objectionable. Their sum may be determined with fair accuracy by
Sulman and Berry's method: 50 grms. of the sample are diluted with twice
its measure of water, carefully neutralised with acetic acid, and warmed to
expel carbonic acid; when cold, a solution of basic lead acetate is added in
slight but distinct excess, and the mixture well agitated. The formation of an
abundant precipitate, which rapidly subsides, is an indication of
considerable impurity in the sample. To ascertain its amount, the precipitate
is first washed by decantation, and then collected on a tared, or preferably a
double counter-poised filter, where it is further washed, dried at 100° to
105° C., and weighed. The precipitate and filter paper are then ignited
separately in porcelain, at a low red heat, the residues moistened with a few
drops of nitric acid and reignited; the weight of the lead oxide deducted
from that of the original precipitate gives the weight of the organic matter
precipitated by the lead. Raw glycerines contain from 0.5 to 1.0 per cent.
Page 252
~Albuminous Matters.~ An approximate determination of the albuminous
matters may be made by precipitating with basic lead acetate as already
described, and determining the nitrogen by the Kjeldahl method; the
nitrogen multiplied by 6.25 gives the amount of albuminous matter in the
precipitate.
~The Determination of Glycerine.~ The acetin method of Benedikt and
Canton depends upon the conversion of glycerine into triacetin, and the
saponification of the latter, and reduces the estimation of glycerine to an
acidmetric method. About 1.5 grm. of crude glycerine is heated to boiling
with 7 grms. of acetic anhydride, and 3 to 4 grms. of anhydrous sodium
acetate, under an upright condenser for one and a half hours. After cooling,
50 c.c. of water are added, and the mixture heated until all the triacetin has
dissolved. The liquid is then filtered into a large flask, the residue on the
filter is well washed with water, the filtrate quite cooled, phenolphthalein is
added and the fluid exactly neutralised with a dilute (2 to 3 per cent.)
solution of alkali. Twenty-five c.c. of a 10 per cent. caustic soda solution,
which must be accurately standardised upon normal acid, are then pipetted
into the liquid, which is heated to boiling for ten minutes to saponify the
triacetin, and the excess of alkali is then titrated back with normal acid. One
c.c. of normal acid corresponds to .03067 grm. of glycerine.
~Precautions.~—The heating must be done with a reflux condenser, the
triacetin being somewhat volatile. The sodium acetate used must be quite
anhydrous, or the conversion of the glycerine to triacetyl is imperfect.
Triacetin in contact with water gradually decomposes. After acetylation is
complete, therefore, the operations must be conducted as rapidly as
possible. It is necessary to neutralise the free acetic acid very cautiously,
and with rapid agitation, so that the alkali may not be locally in excess.
matters may be made by precipitating with basic lead acetate as already
described, and determining the nitrogen by the Kjeldahl method; the
nitrogen multiplied by 6.25 gives the amount of albuminous matter in the
precipitate.
~The Determination of Glycerine.~ The acetin method of Benedikt and
Canton depends upon the conversion of glycerine into triacetin, and the
saponification of the latter, and reduces the estimation of glycerine to an
acidmetric method. About 1.5 grm. of crude glycerine is heated to boiling
with 7 grms. of acetic anhydride, and 3 to 4 grms. of anhydrous sodium
acetate, under an upright condenser for one and a half hours. After cooling,
50 c.c. of water are added, and the mixture heated until all the triacetin has
dissolved. The liquid is then filtered into a large flask, the residue on the
filter is well washed with water, the filtrate quite cooled, phenolphthalein is
added and the fluid exactly neutralised with a dilute (2 to 3 per cent.)
solution of alkali. Twenty-five c.c. of a 10 per cent. caustic soda solution,
which must be accurately standardised upon normal acid, are then pipetted
into the liquid, which is heated to boiling for ten minutes to saponify the
triacetin, and the excess of alkali is then titrated back with normal acid. One
c.c. of normal acid corresponds to .03067 grm. of glycerine.
~Precautions.~—The heating must be done with a reflux condenser, the
triacetin being somewhat volatile. The sodium acetate used must be quite
anhydrous, or the conversion of the glycerine to triacetyl is imperfect.
Triacetin in contact with water gradually decomposes. After acetylation is
complete, therefore, the operations must be conducted as rapidly as
possible. It is necessary to neutralise the free acetic acid very cautiously,
and with rapid agitation, so that the alkali may not be locally in excess.
Page 253
~The Lead Oxide Method.~—Two grms. of sample are mixed with about
40 grms. of pure litharge, and heated in an air bath to 130° C. until the
weight becomes constant, care being taken that the litharge is free from
such lead compounds and other substances as might injuriously affect the
results, and that the heating of the mixture takes place in an air bath free
from carbonic acid. The increase in weight in the litharge, minus the weight
of substance not volatilisable from 2 grms. of glycerine at 160° C.,
multiplied by the factor 1.243, is taken as the weight of glycerine in the 2
grms. of sample. The glycerine must be fairly pure, and free from resinous
substances and SO_{3}, to give good results by this process.
~Analysis of the "Waste Acids" from the Manufacture of Nitro-Glycerine
or Gun-Cotton.~ Determine the specific gravity by the specific gravity
bottle or hydrometer, and the oxides of nitrogen by the permanganate
method described under nitro-glycerine. Now determine the total acidity of
the mixture by means of a tenth normal solution of sodium hydrate, and
calculate it as nitric acid (HNO_{3}), then determine the nitric acid by
means of Lungé nitrometer, and subtract percentage found from total
acidity, and calculate the difference into sulphuric acid, thus:—
Total acidity equals 97.46 per cent.—11.07 per cent. HNO_{3} = 86.39
per cent., then (86.39 x 49)/63 = 67.20 per cent. H_{2}SO_{4}.
Then analysis of sample will be:—
Sulphuric acid = 67.20 per cent. |
Nitric acid = 11.07 " |- Specific gravity = 1.7075.
Water = 12.73 " |
This method is accurate enough for general use in the nitric acid factory.
The acid mixture may be taken by volume for determining nitric oxide in
40 grms. of pure litharge, and heated in an air bath to 130° C. until the
weight becomes constant, care being taken that the litharge is free from
such lead compounds and other substances as might injuriously affect the
results, and that the heating of the mixture takes place in an air bath free
from carbonic acid. The increase in weight in the litharge, minus the weight
of substance not volatilisable from 2 grms. of glycerine at 160° C.,
multiplied by the factor 1.243, is taken as the weight of glycerine in the 2
grms. of sample. The glycerine must be fairly pure, and free from resinous
substances and SO_{3}, to give good results by this process.
~Analysis of the "Waste Acids" from the Manufacture of Nitro-Glycerine
or Gun-Cotton.~ Determine the specific gravity by the specific gravity
bottle or hydrometer, and the oxides of nitrogen by the permanganate
method described under nitro-glycerine. Now determine the total acidity of
the mixture by means of a tenth normal solution of sodium hydrate, and
calculate it as nitric acid (HNO_{3}), then determine the nitric acid by
means of Lungé nitrometer, and subtract percentage found from total
acidity, and calculate the difference into sulphuric acid, thus:—
Total acidity equals 97.46 per cent.—11.07 per cent. HNO_{3} = 86.39
per cent., then (86.39 x 49)/63 = 67.20 per cent. H_{2}SO_{4}.
Then analysis of sample will be:—
Sulphuric acid = 67.20 per cent. |
Nitric acid = 11.07 " |- Specific gravity = 1.7075.
Water = 12.73 " |
This method is accurate enough for general use in the nitric acid factory.
The acid mixture may be taken by volume for determining nitric oxide in
Page 254
nitrometer. Two c.c. is a convenient quantity in the above case, then 2 x
1.7075 (specific gravity) = 3.414 grms. taken, gave 145 c.c. NO (barometer
= 748 mm, and temperature = 15°C.) equals 134.9 c.c. (corr.) and as 1 c.c.
NO = .0282 grm. HNO_{3} 135 x .0282 = .378 grm. = 11.07 per cent. nitric
acid.
~Sodium Nitrate.~ Determine moisture and chlorine by the usual
methods, and the total, NaNO_{3}, by means of nitrometer—0.45 grm. is a
very convenient quantity to work on (gives about 123 c.c. gas); grind very
fine, and dissolve in a very little hot water in the cup of the nitrometer; use
about 15 c.c. concentrated H_{2}SO_{4}. One cubic cent. of NO equals
.003805 grm. of NaNO_{3}. The insoluble matter, both organic and
inorganic, should also be determined, also sulphate of soda and lime tested
for.
~Analysis of Mercury Fulminate (Divers and Kawakita's Method).~—A
weighed quantity of mercury fulminate is added to excess, but measured
quantity of fuming hydrochloric acid contained in a retort connected with a
receiver holding water. After heating for some time, the contents of the
retort and receiver are mixed and diluted, and the mercury is precipitated by
hydrogen sulphide. By warming and exposure to the air in open vessels the
hydrogen sulphide is for the most part dissipated. The solution is then
titrated with potassium hydroxide (KOH), as well as another quantity of
hydrochloric acid, equal to that used with the fulminate. As the mercury
chloride is reconverted into hydrochloric acid by the hydrogen sulphide,
and as the hydroxylamine does not neutralise to litmus the hydrochloric
acid combined with it, there is an equal amount of hydrochloric acid free or
available in the two solutions. Any excess of acid in the one which has
received the fulminate will therefore be due to the formic acid generated
from the fulminate. Dr. Divers and M. Kawakita, working by this method,
1.7075 (specific gravity) = 3.414 grms. taken, gave 145 c.c. NO (barometer
= 748 mm, and temperature = 15°C.) equals 134.9 c.c. (corr.) and as 1 c.c.
NO = .0282 grm. HNO_{3} 135 x .0282 = .378 grm. = 11.07 per cent. nitric
acid.
~Sodium Nitrate.~ Determine moisture and chlorine by the usual
methods, and the total, NaNO_{3}, by means of nitrometer—0.45 grm. is a
very convenient quantity to work on (gives about 123 c.c. gas); grind very
fine, and dissolve in a very little hot water in the cup of the nitrometer; use
about 15 c.c. concentrated H_{2}SO_{4}. One cubic cent. of NO equals
.003805 grm. of NaNO_{3}. The insoluble matter, both organic and
inorganic, should also be determined, also sulphate of soda and lime tested
for.
~Analysis of Mercury Fulminate (Divers and Kawakita's Method).~—A
weighed quantity of mercury fulminate is added to excess, but measured
quantity of fuming hydrochloric acid contained in a retort connected with a
receiver holding water. After heating for some time, the contents of the
retort and receiver are mixed and diluted, and the mercury is precipitated by
hydrogen sulphide. By warming and exposure to the air in open vessels the
hydrogen sulphide is for the most part dissipated. The solution is then
titrated with potassium hydroxide (KOH), as well as another quantity of
hydrochloric acid, equal to that used with the fulminate. As the mercury
chloride is reconverted into hydrochloric acid by the hydrogen sulphide,
and as the hydroxylamine does not neutralise to litmus the hydrochloric
acid combined with it, there is an equal amount of hydrochloric acid free or
available in the two solutions. Any excess of acid in the one which has
received the fulminate will therefore be due to the formic acid generated
from the fulminate. Dr. Divers and M. Kawakita, working by this method,
Page 255
have obtained 31.31 per cent. formic acid, instead of 32.40 required by
theory. (Jour. Chem. Soc., p. 17, 1884.)
Divers and Kawakita proceed thus: 2.351 grms. dissolved, as already
described, in HCl, and afterwards diluted, gave mercury sulphide equal to
70.40 per cent. mercury. The same solution, after removal of mercury,
titrated by iodine for hydroxylamine, gave nitrogen equal to 9.85 per cent.,
and when evaporated with hydroxyl ammonium chloride equal to 9.55 per
cent. A solution of 2.6665 grms. fulminate in HCl of known amount, after
removal of mercury by hydrogen sulphide, gave by titration with potassium
hydrate, formic acid equal to 8.17 per cent. of carbon. Collecting and
comparing with calculation from formula we get—
Calc. I. II. III.
Mercury 70.42 70.40 … …
Nitrogen 9.86 9.85 9.55 …
Carbon 8.45 … … 8.17
Oxygen 11.27 … … …
_______
100.00
~The Analysis of Cap Composition.~—Messrs F.W. Jones and F.A.
Willcox (Chem. News, Dec. 11, 1896) have proposed the following process
for the analysis of this substance:—Cap composition usually consists of the
ingredients—potassium chlorate, antimony sulphide, and mercury
fulminate, and to estimate these substances in the presence of each other by
ordinary analytical methods is a difficult process. Since the separation of
antimony sulphide and mercury fulminate in the presence of potassium
chlorate necessitates the treatment of the mixture with hydrochloric acid,
and this produces an evolution of hydrogen sulphide from the sulphide, and
theory. (Jour. Chem. Soc., p. 17, 1884.)
Divers and Kawakita proceed thus: 2.351 grms. dissolved, as already
described, in HCl, and afterwards diluted, gave mercury sulphide equal to
70.40 per cent. mercury. The same solution, after removal of mercury,
titrated by iodine for hydroxylamine, gave nitrogen equal to 9.85 per cent.,
and when evaporated with hydroxyl ammonium chloride equal to 9.55 per
cent. A solution of 2.6665 grms. fulminate in HCl of known amount, after
removal of mercury by hydrogen sulphide, gave by titration with potassium
hydrate, formic acid equal to 8.17 per cent. of carbon. Collecting and
comparing with calculation from formula we get—
Calc. I. II. III.
Mercury 70.42 70.40 … …
Nitrogen 9.86 9.85 9.55 …
Carbon 8.45 … … 8.17
Oxygen 11.27 … … …
_______
100.00
~The Analysis of Cap Composition.~—Messrs F.W. Jones and F.A.
Willcox (Chem. News, Dec. 11, 1896) have proposed the following process
for the analysis of this substance:—Cap composition usually consists of the
ingredients—potassium chlorate, antimony sulphide, and mercury
fulminate, and to estimate these substances in the presence of each other by
ordinary analytical methods is a difficult process. Since the separation of
antimony sulphide and mercury fulminate in the presence of potassium
chlorate necessitates the treatment of the mixture with hydrochloric acid,
and this produces an evolution of hydrogen sulphide from the sulphide, and
Page 256
a consequent precipitation of sulphur; and potassium chlorate cannot be
separated from the other ingredients by treatment with water, owing to the
appreciable solubility of mercury fulminate in cold water.
In the course of some experiments on the solubility of mercury fulminate
Messrs Jones and Willcox observed that this body was readily soluble in
acetone and other ethereal solvents when they were saturated with ammonia
gas, and that chlorate of potash and sulphide of antimony were insoluble in
pure acetone saturated with ammonia; these observations at once afforded a
simple method of separating the three ingredients of cap composition. By
employing this solution of acetone and ammonia an analysis can be made in
a comparatively short time, and yields results of sufficient accuracy for all
technical purposes. The following are the details of the process:—
A tared filter paper is placed in a funnel to the neck of which has been
fitted a piece of rubber tubing provided with a clip. The paper is moistened
with a solution of acetone and ammonia, the cap composition is weighed off
directly on to the filter paper and is then covered with the solution of
acetone and ammonia and allowed to stand thirty-four hours. It is then
washed repeatedly with the same solution until the washings give no
coloration with ammonium sulphide, and afterwards washed with acetone
until washings give no residue on evaporation dried and weighed. The paper
is again put in the funnel and washed with water until free from potassium
chlorate, dried and weighed.
If c = weight of composition taken,
d = " " filter paper,
a = " after first extraction,
b = " " second extraction,
then c+d-a = weight of fulminate,
separated from the other ingredients by treatment with water, owing to the
appreciable solubility of mercury fulminate in cold water.
In the course of some experiments on the solubility of mercury fulminate
Messrs Jones and Willcox observed that this body was readily soluble in
acetone and other ethereal solvents when they were saturated with ammonia
gas, and that chlorate of potash and sulphide of antimony were insoluble in
pure acetone saturated with ammonia; these observations at once afforded a
simple method of separating the three ingredients of cap composition. By
employing this solution of acetone and ammonia an analysis can be made in
a comparatively short time, and yields results of sufficient accuracy for all
technical purposes. The following are the details of the process:—
A tared filter paper is placed in a funnel to the neck of which has been
fitted a piece of rubber tubing provided with a clip. The paper is moistened
with a solution of acetone and ammonia, the cap composition is weighed off
directly on to the filter paper and is then covered with the solution of
acetone and ammonia and allowed to stand thirty-four hours. It is then
washed repeatedly with the same solution until the washings give no
coloration with ammonium sulphide, and afterwards washed with acetone
until washings give no residue on evaporation dried and weighed. The paper
is again put in the funnel and washed with water until free from potassium
chlorate, dried and weighed.
If c = weight of composition taken,
d = " " filter paper,
a = " after first extraction,
b = " " second extraction,
then c+d-a = weight of fulminate,
Page 257
c+d-a-b = " " KClO_{3},
b-d = " " sulphide of antimony.
The composition should be finely ground in an agate mortar.
The results of the analysis by this method of two mixtures of known
composition are given below—
___________________________________________________________
_____________ | | | | | | A | B | | | | | | | Percentage | Percentage | Percentage |
Percentage | | | Taken. | Found. | Taken. | Found. |
|____________________|____________|____________|____________|___
_________| | | | | | | | Antimony Sulphide | 36.47 | 36.25 | 37.34 | 37.22 | |
Potassium Chlorate | 33.25 | 33.71 | 46.03 | 46.43 | | Mercury Fulminate |
30.27 | 30.02 | 16.61 | 16.34 |
|____________________|____________|____________|____________|___
_________|
Dr. H.W. Brownsdon's (Jour. Soc. Chem. Ind., xxiv., April 1905) process
is as follows:—The cap composition is removed by squeezing the cap with
pliers, while held over a porcelain basin of about 200 c.c. capacity, and
removing the loosened foil and broken composition by means of a pointed
wooden chip. Composition adhering to the shell or foil is loosened by
alcohol, and washed into the dish by means of alcohol in a small wash
bottle. The shell and foil are put to one side and subsequently weighed
when dry. The composition in the dish is broken down quite fine with a flat-
headed glass rod, and the alcohol evaporated on the water bath till the
residue is moist, but not quite dry, 25 c.c. of water are then added, and the
composition well stirred from the bottom. After the addition of 0.5 grm. of
pure sodium, thiosulphate, the contents of the dish, is well stirred for two
and a half minutes. One drop of methyl orange is then added, and the
solution titrated with N/20 sulphuric acid, which has been standardised
b-d = " " sulphide of antimony.
The composition should be finely ground in an agate mortar.
The results of the analysis by this method of two mixtures of known
composition are given below—
___________________________________________________________
_____________ | | | | | | A | B | | | | | | | Percentage | Percentage | Percentage |
Percentage | | | Taken. | Found. | Taken. | Found. |
|____________________|____________|____________|____________|___
_________| | | | | | | | Antimony Sulphide | 36.47 | 36.25 | 37.34 | 37.22 | |
Potassium Chlorate | 33.25 | 33.71 | 46.03 | 46.43 | | Mercury Fulminate |
30.27 | 30.02 | 16.61 | 16.34 |
|____________________|____________|____________|____________|___
_________|
Dr. H.W. Brownsdon's (Jour. Soc. Chem. Ind., xxiv., April 1905) process
is as follows:—The cap composition is removed by squeezing the cap with
pliers, while held over a porcelain basin of about 200 c.c. capacity, and
removing the loosened foil and broken composition by means of a pointed
wooden chip. Composition adhering to the shell or foil is loosened by
alcohol, and washed into the dish by means of alcohol in a small wash
bottle. The shell and foil are put to one side and subsequently weighed
when dry. The composition in the dish is broken down quite fine with a flat-
headed glass rod, and the alcohol evaporated on the water bath till the
residue is moist, but not quite dry, 25 c.c. of water are then added, and the
composition well stirred from the bottom. After the addition of 0.5 grm. of
pure sodium, thiosulphate, the contents of the dish, is well stirred for two
and a half minutes. One drop of methyl orange is then added, and the
solution titrated with N/20 sulphuric acid, which has been standardised
Page 258
against weighings of 0.05-0.1 grm. fulminate to which 25 c.c. of water is
added in a porcelain dish, then 0.5 grm. of thiosulphate, and after stirring
for two and a half minutes, titrated with N/20 sulphuric acid. The small
amount of antimony sulphide present does not interfere with the recognition
of the end point. After titration, the solution is filtered through a small 5-1/2
cm. filter paper, which retains the antimony sulphide. The filter paper
containing the Sb_{2}S_{3} is well washed and then transferred to a large
6 by 1 test tube. Five c.c. of strong hydrochloric acid are added, and the
contents of the tube boiled gently for a few seconds until the sulphide is
dissolved and all the H_{2}S driven off or decomposed: 2-3 c.c. of a
saturated solution of tartaric acid are added, and the contents of the tube
washed into a 250 c.c. Erlenmeyer flask. The solution is then nearly
neutralised with sodium carbonate, excess of bi-carbonate added, and after
the addition of some starch solution titrated with N/20 iodine solution. This
method for small quantities of stibnite is both quick and accurate, the error
being about ±0.0003 grm. Sb_{2}S_{3} at the outside.
The tendency of this method is to give slightly low figures for the
fulminate, but since these are uniform within a negligible error, it does not
affect the value of the results as a criterion of uniformity. The following test
results were obtained by Dr Brownsdon:—
___________________________________________________________
_ | | | | | Fulminate Taken. | Fulminate Found. | Error. | | Grm. | Grm. | Grm. | |
| | | | 0.0086 | 0.0083 | -0.0003 | | 0.0082 | 0.0081 | -0.0001 | | 0.0074 | 0.0071
| -0.0003 | | 0.0068 | 0.0066 | -0.0002 |
|____________________|___________________|___________________| |
| | | | Stibnite Taken. |Sb_{2}S_{3}, Found.| Error. | | Grm. | Grm. | Grm. | | | |
| | 0.0085 | 0.0084 | -0.0001 | | 0.0098 | 0.0099 | +0.0001 | | 0.0160 | 0.0157 |
-0.0003 | | 0.0099 | 0.0100 | +0.0001 |
|____________________|___________________|___________________|
added in a porcelain dish, then 0.5 grm. of thiosulphate, and after stirring
for two and a half minutes, titrated with N/20 sulphuric acid. The small
amount of antimony sulphide present does not interfere with the recognition
of the end point. After titration, the solution is filtered through a small 5-1/2
cm. filter paper, which retains the antimony sulphide. The filter paper
containing the Sb_{2}S_{3} is well washed and then transferred to a large
6 by 1 test tube. Five c.c. of strong hydrochloric acid are added, and the
contents of the tube boiled gently for a few seconds until the sulphide is
dissolved and all the H_{2}S driven off or decomposed: 2-3 c.c. of a
saturated solution of tartaric acid are added, and the contents of the tube
washed into a 250 c.c. Erlenmeyer flask. The solution is then nearly
neutralised with sodium carbonate, excess of bi-carbonate added, and after
the addition of some starch solution titrated with N/20 iodine solution. This
method for small quantities of stibnite is both quick and accurate, the error
being about ±0.0003 grm. Sb_{2}S_{3} at the outside.
The tendency of this method is to give slightly low figures for the
fulminate, but since these are uniform within a negligible error, it does not
affect the value of the results as a criterion of uniformity. The following test
results were obtained by Dr Brownsdon:—
___________________________________________________________
_ | | | | | Fulminate Taken. | Fulminate Found. | Error. | | Grm. | Grm. | Grm. | |
| | | | 0.0086 | 0.0083 | -0.0003 | | 0.0082 | 0.0081 | -0.0001 | | 0.0074 | 0.0071
| -0.0003 | | 0.0068 | 0.0066 | -0.0002 |
|____________________|___________________|___________________| |
| | | | Stibnite Taken. |Sb_{2}S_{3}, Found.| Error. | | Grm. | Grm. | Grm. | | | |
| | 0.0085 | 0.0084 | -0.0001 | | 0.0098 | 0.0099 | +0.0001 | | 0.0160 | 0.0157 |
-0.0003 | | 0.0099 | 0.0100 | +0.0001 |
|____________________|___________________|___________________|
Page 259
TABLE FOR CORRECTION OF VOLUMES OF GASES FOR TEMPERATURE, GIVING
THE DIVISOR FOR THE FORMULA.
V_{1} = V x B/(760 x (1 + dt)) (d = 0.003665) 1 + dt from 0° to 30° C.
___________________________________________________________
| | | | | t. | 760x(1+dt). | t. | 760x(1+dt). | t. | 760x(1+dt).
_____|_____________|_____|_____________|_____|_____________ | | | | |
°C. | | °C. | | °C. | 0.0 | 750.000 | 1.7 | 764.7352 | 3.4 | 769.4704 .1 | 760.2785
| .8 | 765.0137 | .5 | 769.7489 .2 | 760.5571 | .9 | 765.2923 | .6 | 770.0274 .3 |
760.8356 | 2.0 | 765.5708 | .7 | 770.3060 .4 | 761.1142 | .1 | 765.8493 | .8 |
770.5845 .5 | 761.3927 | .2 | 766.1279 | .9 | 770.8631 .6 | 761.6712 | .3 |
766.4064 | 4.0 | 771.1416 .7 | 761.9498 | .4 | 766.6850 | .1 | 771.4201 .8 |
762.2283 | .5 | 766.9635 | .2 | 771.6987 .9 | 762.5069 | .6 | 767.2420 | .3 |
771.9772 1.0 | 762.7854 | .7 | 767.5206 | .4 | 772.2558 .1 | 763.0639 | .8 |
767.7991 | .5 | 772.5343 .2 | 763.3425 | .9 | 768.0777 | .6 | 772.8128 .3 |
763.6210 | 3.0 | 768.3562 | .7 | 773.0914 .4 | 763.8996 | .1 | 768.6347 | .8 |
773.3699 .5 | 764.1781 | .2 | 768.9133 | .9 | 773.6485 .6 | 764.4566 | .3 |
769.1918 | 5.0 | 773.9270
_____|_____________|_____|_____________|_____|_____________
___________________________________________________________ | |
| | | t. | 760x(1+dt). | t. | 760x(1+dt). | t. | 760x(1+dt).
_____|_____________|_____|_____________|_____|_____________ | | | | |
°C. | | °C. | | °C. | 5.1 | 774.2055 | .9 | 787.5755 | .7 | 800.9454 .2 | 774.4841
|10.0 | 787.8540 | .8 | 801.2239 .3 | 774.7626 | .1 | 788.1325 | .9 | 801.5025
.4 | 775.0412 | .2 | 788.4111 |15.0 | 801.7810 .5 | 775.3197 | .3 | 788.6896 | .1
| 802.0595 .6 | 775.5982 | .4 | 788.9682 | .2 | 802.3381 .7 | 775.8768 | .5 |
789.2467 | .3 | 802.6166 .8 | 776.1553 | .6 | 789.5252 | .4 | 802.8952 .9 |
776.4339 | .7 | 789.8038 | .5 | 803.1737 6.0 | 776.7124 | .8 | 790.0823 | .6 |
803.4522 .1 | 776.9909 | .9 | 790.3609 | .7 | 803.7308 .2 | 777.2695 |11.0 |
790.6394 | .8 | 804.0093 .3 | 777.5480 | .1 | 790.9179 | .9 | 804.2879 .4 |
777.8266 | .2 | 791.1965 |16.0 | 804.5664 .5 | 778.1051 | .3 | 791.4750 | .1 |
THE DIVISOR FOR THE FORMULA.
V_{1} = V x B/(760 x (1 + dt)) (d = 0.003665) 1 + dt from 0° to 30° C.
___________________________________________________________
| | | | | t. | 760x(1+dt). | t. | 760x(1+dt). | t. | 760x(1+dt).
_____|_____________|_____|_____________|_____|_____________ | | | | |
°C. | | °C. | | °C. | 0.0 | 750.000 | 1.7 | 764.7352 | 3.4 | 769.4704 .1 | 760.2785
| .8 | 765.0137 | .5 | 769.7489 .2 | 760.5571 | .9 | 765.2923 | .6 | 770.0274 .3 |
760.8356 | 2.0 | 765.5708 | .7 | 770.3060 .4 | 761.1142 | .1 | 765.8493 | .8 |
770.5845 .5 | 761.3927 | .2 | 766.1279 | .9 | 770.8631 .6 | 761.6712 | .3 |
766.4064 | 4.0 | 771.1416 .7 | 761.9498 | .4 | 766.6850 | .1 | 771.4201 .8 |
762.2283 | .5 | 766.9635 | .2 | 771.6987 .9 | 762.5069 | .6 | 767.2420 | .3 |
771.9772 1.0 | 762.7854 | .7 | 767.5206 | .4 | 772.2558 .1 | 763.0639 | .8 |
767.7991 | .5 | 772.5343 .2 | 763.3425 | .9 | 768.0777 | .6 | 772.8128 .3 |
763.6210 | 3.0 | 768.3562 | .7 | 773.0914 .4 | 763.8996 | .1 | 768.6347 | .8 |
773.3699 .5 | 764.1781 | .2 | 768.9133 | .9 | 773.6485 .6 | 764.4566 | .3 |
769.1918 | 5.0 | 773.9270
_____|_____________|_____|_____________|_____|_____________
___________________________________________________________ | |
| | | t. | 760x(1+dt). | t. | 760x(1+dt). | t. | 760x(1+dt).
_____|_____________|_____|_____________|_____|_____________ | | | | |
°C. | | °C. | | °C. | 5.1 | 774.2055 | .9 | 787.5755 | .7 | 800.9454 .2 | 774.4841
|10.0 | 787.8540 | .8 | 801.2239 .3 | 774.7626 | .1 | 788.1325 | .9 | 801.5025
.4 | 775.0412 | .2 | 788.4111 |15.0 | 801.7810 .5 | 775.3197 | .3 | 788.6896 | .1
| 802.0595 .6 | 775.5982 | .4 | 788.9682 | .2 | 802.3381 .7 | 775.8768 | .5 |
789.2467 | .3 | 802.6166 .8 | 776.1553 | .6 | 789.5252 | .4 | 802.8952 .9 |
776.4339 | .7 | 789.8038 | .5 | 803.1737 6.0 | 776.7124 | .8 | 790.0823 | .6 |
803.4522 .1 | 776.9909 | .9 | 790.3609 | .7 | 803.7308 .2 | 777.2695 |11.0 |
790.6394 | .8 | 804.0093 .3 | 777.5480 | .1 | 790.9179 | .9 | 804.2879 .4 |
777.8266 | .2 | 791.1965 |16.0 | 804.5664 .5 | 778.1051 | .3 | 791.4750 | .1 |
Page 260
804.8449 .6 | 778.3836 | .4 | 791.7536 | .2 | 805.1235 .7 | 778.6622 | .5 |
792.0321 | .3 | 805.4020 .8 | 778.9407 | .6 | 792.3106 | .4 | 805.6806 .9 |
779.2193 | .7 | 792.5892 | .5 | 805.9591 7.0 | 779.4978 | .8 | 792.8677 | .6 |
806.2376 .1 | 779.7763 | .9 | 793.1463 | .7 | 806.5162 .2 | 780.0549 |12.0 |
793.4248 | .8 | 806.7947 .3 | 780.3334 | .1 | 793.7033 | .9 | 807.0733 .4 |
780.6120 | .2 | 793.9819 |17.0 | 807.3518 .5 | 780.8905 | .3 | 794.2604 | .1 |
807.6303 .6 | 781.1690 | .4 | 794.5390 | .2 | 807.9089 .7 | 781.4476 | .5 |
794.8175 | .3 | 808.1874 .8 | 781.7261 | .6 | 795.0960 | .4 | 808.4660 .9 |
782.0047 | .7 | 795.3746 | .5 | 808.7445 8.0 | 782.2832 | .8 | 795.6531 | .6 |
809.0230 .1 | 782.5617 | .9 | 795.9317 | .7 | 809.3016 .2 | 782.8403 |13.0 |
796.2102 | .8 | 809.5801 .3 | 783.1188 | .1 | 796.4887 | .9 | 809.8587 .4 |
783.3974 | .2 | 796.7673 |18.0 | 810.1372 .5 | 783.6959 | .3 | 797.0458 | .1 |
810.4175 .6 | 783.9544 | .4 | 797.3244 | .2 | 810.6943 .7 | 784.2330 | .5 |
797.6029 | .3 | 810.9728 .8 | 784.5115 | .6 | 797.8814 | .4 | 811.2514 .9 |
784.7901 | .7 | 798.1600 | .5 | 811.5299 9.0 | 785.0686 | .8 | 798.4385 | .6 |
811.8084 .1 | 785.3471 | .9 | 798.7171 | .7 | 812.0870 .2 | 785.6257 |14.0 |
798.9956 | .8 | 812.3655 .3 | 785.9042 | .1 | 799.2741 | .9 | 812.6441 .4 |
786.1828 | .2 | 799.5527 |19.0 | 812.9226 .5 | 786.4613 | .3 | 799.8312 | .1 |
813.2011 .6 | 786.7398 | .4 | 800.1098 | .2 | 813.4797 .7 | 787.0184 | .5 |
800.3883 | .3 | 813.7582 .8 | 787.2969 | .6 | 800.6668 | .4 | 814.0368
_____|_____________|_____|_____________|_____|_____________
___________________________________________________________ | |
| | | t. | 760x(1+dt). | t. | 760x(1+dt). | t. | 760x(1+dt).
_____|_____________|_____|_____________|_____|_____________ | | | | |
°C. | | °C. | | °C. | 19.5 | 814.3153 |23.0 | 824.0642 | .5 | 833.8131 .6 |
814.5938 | .1 | 824.3427 | .6 | 834.0916 .7 | 814.8724 | .2 | 824.6213 | .7 |
834.3702 .8 | 815.1500 | .3 | 824.8998 | .8 | 834.6487 .9 | 815.4925 | .4 |
825.1784 | .9 | 834.9273 20.0 | 815.7080 | .5 | 825.4569 |27.0 | 835.2058 .1 |
815.9865 | .6 | 825.7354 | .1 | 835.4843 .2 | 816.2651 | .7 | 826.0140 | .2 |
835.7629 .3 | 816.5436 | .8 | 826.2925 | .3 | 836.0414 .4 | 816.8222 | .9 |
792.0321 | .3 | 805.4020 .8 | 778.9407 | .6 | 792.3106 | .4 | 805.6806 .9 |
779.2193 | .7 | 792.5892 | .5 | 805.9591 7.0 | 779.4978 | .8 | 792.8677 | .6 |
806.2376 .1 | 779.7763 | .9 | 793.1463 | .7 | 806.5162 .2 | 780.0549 |12.0 |
793.4248 | .8 | 806.7947 .3 | 780.3334 | .1 | 793.7033 | .9 | 807.0733 .4 |
780.6120 | .2 | 793.9819 |17.0 | 807.3518 .5 | 780.8905 | .3 | 794.2604 | .1 |
807.6303 .6 | 781.1690 | .4 | 794.5390 | .2 | 807.9089 .7 | 781.4476 | .5 |
794.8175 | .3 | 808.1874 .8 | 781.7261 | .6 | 795.0960 | .4 | 808.4660 .9 |
782.0047 | .7 | 795.3746 | .5 | 808.7445 8.0 | 782.2832 | .8 | 795.6531 | .6 |
809.0230 .1 | 782.5617 | .9 | 795.9317 | .7 | 809.3016 .2 | 782.8403 |13.0 |
796.2102 | .8 | 809.5801 .3 | 783.1188 | .1 | 796.4887 | .9 | 809.8587 .4 |
783.3974 | .2 | 796.7673 |18.0 | 810.1372 .5 | 783.6959 | .3 | 797.0458 | .1 |
810.4175 .6 | 783.9544 | .4 | 797.3244 | .2 | 810.6943 .7 | 784.2330 | .5 |
797.6029 | .3 | 810.9728 .8 | 784.5115 | .6 | 797.8814 | .4 | 811.2514 .9 |
784.7901 | .7 | 798.1600 | .5 | 811.5299 9.0 | 785.0686 | .8 | 798.4385 | .6 |
811.8084 .1 | 785.3471 | .9 | 798.7171 | .7 | 812.0870 .2 | 785.6257 |14.0 |
798.9956 | .8 | 812.3655 .3 | 785.9042 | .1 | 799.2741 | .9 | 812.6441 .4 |
786.1828 | .2 | 799.5527 |19.0 | 812.9226 .5 | 786.4613 | .3 | 799.8312 | .1 |
813.2011 .6 | 786.7398 | .4 | 800.1098 | .2 | 813.4797 .7 | 787.0184 | .5 |
800.3883 | .3 | 813.7582 .8 | 787.2969 | .6 | 800.6668 | .4 | 814.0368
_____|_____________|_____|_____________|_____|_____________
___________________________________________________________ | |
| | | t. | 760x(1+dt). | t. | 760x(1+dt). | t. | 760x(1+dt).
_____|_____________|_____|_____________|_____|_____________ | | | | |
°C. | | °C. | | °C. | 19.5 | 814.3153 |23.0 | 824.0642 | .5 | 833.8131 .6 |
814.5938 | .1 | 824.3427 | .6 | 834.0916 .7 | 814.8724 | .2 | 824.6213 | .7 |
834.3702 .8 | 815.1500 | .3 | 824.8998 | .8 | 834.6487 .9 | 815.4925 | .4 |
825.1784 | .9 | 834.9273 20.0 | 815.7080 | .5 | 825.4569 |27.0 | 835.2058 .1 |
815.9865 | .6 | 825.7354 | .1 | 835.4843 .2 | 816.2651 | .7 | 826.0140 | .2 |
835.7629 .3 | 816.5436 | .8 | 826.2925 | .3 | 836.0414 .4 | 816.8222 | .9 |
Page 261
826.5711 | .4 | 836.3200 .5 | 817.1007 |24.0 | 826.8496 | .5 | 836.5985 .6 |
817.3792 | .1 | 827.1281 | .6 | 836.8770 .7 | 817.6578 | .2 | 827.4067 | .7 |
837.1556 .8 | 817.9363 | .3 | 827.6852 | .8 | 837.4341 .9 | 818.2149 | .4 |
827.9638 | .9 | 837.7127 21.0 | 818.4934 | .5 | 828.2423 |28.0 | 837.9912 .1 |
818.7719 | .6 | 828.5208 | .1 | 838.2697 .2 | 819.0505 | .7 | 828.7994 | .2 |
838.5483 .3 | 819.3290 | .8 | 829.0779 | .3 | 838.8268 .4 | 819.6076 | .9 |
829.3565 | .4 | 839.1054 .5 | 819.8861 |25.0 | 829.6350 | .5 | 839.3839 .6 |
820.1646 | .1 | 829.9135 | .6 | 839.6624 .7 | 820.4432 | .2 | 830.1921 | .7 |
839.9410 .8 | 820.7217 | .3 | 830.4706 | .8 | 840.2195 .9 | 821.0003 | .4 |
830.7492 | .9 | 840.4981 22.0 | 821.2788 | .5 | 831.0277 |29.0 | 840.7766 .1 |
821.5573 | .6 | 831.3062 | .1 | 841.0551 .2 | 821.8859 | .7 | 831.5848 | .2 |
841.3337 .3 | 822.1144 | .8 | 831.8633 | .3 | 841.6122 .4 | 822.3930 | .9 |
832.1419 | .4 | 841.8908 .5 | 822.6715 |26.0 | 832.4204 | .5 | 842.1693 .6 |
822.9500 | .1 | 832.6989 | .6 | 842.4478 .7 | 823.2286 | .2 | 832.9775 | .7 |
842.7264 .8 | 823.5071 | .3 | 833.2560 | .8 | 843.0049 .9 | 823.7857 | .4 |
833.5346 | .9 | 843.2835 | | | |30.0 | 843.5620
_____|_____________|_____|_____________|_____|_____________
817.3792 | .1 | 827.1281 | .6 | 836.8770 .7 | 817.6578 | .2 | 827.4067 | .7 |
837.1556 .8 | 817.9363 | .3 | 827.6852 | .8 | 837.4341 .9 | 818.2149 | .4 |
827.9638 | .9 | 837.7127 21.0 | 818.4934 | .5 | 828.2423 |28.0 | 837.9912 .1 |
818.7719 | .6 | 828.5208 | .1 | 838.2697 .2 | 819.0505 | .7 | 828.7994 | .2 |
838.5483 .3 | 819.3290 | .8 | 829.0779 | .3 | 838.8268 .4 | 819.6076 | .9 |
829.3565 | .4 | 839.1054 .5 | 819.8861 |25.0 | 829.6350 | .5 | 839.3839 .6 |
820.1646 | .1 | 829.9135 | .6 | 839.6624 .7 | 820.4432 | .2 | 830.1921 | .7 |
839.9410 .8 | 820.7217 | .3 | 830.4706 | .8 | 840.2195 .9 | 821.0003 | .4 |
830.7492 | .9 | 840.4981 22.0 | 821.2788 | .5 | 831.0277 |29.0 | 840.7766 .1 |
821.5573 | .6 | 831.3062 | .1 | 841.0551 .2 | 821.8859 | .7 | 831.5848 | .2 |
841.3337 .3 | 822.1144 | .8 | 831.8633 | .3 | 841.6122 .4 | 822.3930 | .9 |
832.1419 | .4 | 841.8908 .5 | 822.6715 |26.0 | 832.4204 | .5 | 842.1693 .6 |
822.9500 | .1 | 832.6989 | .6 | 842.4478 .7 | 823.2286 | .2 | 832.9775 | .7 |
842.7264 .8 | 823.5071 | .3 | 833.2560 | .8 | 843.0049 .9 | 823.7857 | .4 |
833.5346 | .9 | 843.2835 | | | |30.0 | 843.5620
_____|_____________|_____|_____________|_____|_____________
Page 262
CHAPTER VIII.
FIRING POINT OF EXPLOSIVES, HEAT TESTS, &c.
Horsley's Apparatus—Table of Firing points—The Government Heat-
Test
Apparatus for Dynamites—Nitro-Glycerine, Nitro-Cotton, and Smokeless
Powders—Liquefaction and Exudation Tests—Page's Regulator for Heat-
Test
Apparatus—Specific Gravities of Explosives—Table of Temperature of
Detonation, Sensitiveness, &c.
~The Firing Point of Explosives.~—The firing point of an explosive may
be determined as follows:—A copper dish, about 3 inches deep, and 6 or
more wide, and fitted with a lid, also of copper, is required. The lid contains
several small holes, into each of which is soldered a thick copper tube about
5 mm. in diameter, and 3 inches long, with a rather larger one in the centre
in which to place a thermometer. The dish is filled with Rose's metal, or
paraffin, according to the probable temperature required. The firing point is
then taken thus:—After putting a little piece of asbestos felt at the bottom of
the centre tube, the thermometer is inserted, and a small quantity of the
explosive to be tested is placed in the other holes; the lid is then placed on
the dish containing the melted paraffin or metal, in such a way that the
copper tubes dip below the surface of the liquid; the temperature of the bath
FIRING POINT OF EXPLOSIVES, HEAT TESTS, &c.
Horsley's Apparatus—Table of Firing points—The Government Heat-
Test
Apparatus for Dynamites—Nitro-Glycerine, Nitro-Cotton, and Smokeless
Powders—Liquefaction and Exudation Tests—Page's Regulator for Heat-
Test
Apparatus—Specific Gravities of Explosives—Table of Temperature of
Detonation, Sensitiveness, &c.
~The Firing Point of Explosives.~—The firing point of an explosive may
be determined as follows:—A copper dish, about 3 inches deep, and 6 or
more wide, and fitted with a lid, also of copper, is required. The lid contains
several small holes, into each of which is soldered a thick copper tube about
5 mm. in diameter, and 3 inches long, with a rather larger one in the centre
in which to place a thermometer. The dish is filled with Rose's metal, or
paraffin, according to the probable temperature required. The firing point is
then taken thus:—After putting a little piece of asbestos felt at the bottom of
the centre tube, the thermometer is inserted, and a small quantity of the
explosive to be tested is placed in the other holes; the lid is then placed on
the dish containing the melted paraffin or metal, in such a way that the
copper tubes dip below the surface of the liquid; the temperature of the bath
Page 263
is now raised until the explosive fires, and the temperature noted. The initial
temperature should also be noted.
THE FIRING POINT OF VARIOUS EXPLOSIVES (by C. E. Munroe).
(Horsley's Apparatus used.)
___________________________________________________________
__________ | | °C. Nitro-glycerine, 5 years old (a single drop taken) | 203-
205 Gun-cotton (compressed military cotton, sp. gr. 1.5) | 192-201 Air-dried
gun-cotton, stored for 4 years | 179-187 Ditto, stored for 1 year | 187-189
Air-dried collodion-cotton, long staple "Red Island | cotton," 3 years old |
186-191 Air-dried collodion, 3 years old, stored wet | 197-199 Hydro-nitro-
cellulose | 201-213 Kieselguhr dynamite, No. 1 | 197-200 Explosive
gelatine | 203-209 Mercury fulminate | 175-181 Gunpowder (shell) | 278-
287 Hill's picric powder (shells) Been in store 10 years. | 273-283 Ditto
(musket) Composed of— | 282-290 Ammonium picrate 42.18 % |
Potassium picrate 53.79 " | Charcoal (alder) 3.85 " | ________ | | 99.82 |
Forcite, No. 1 | 187-200 Atlas powder (75% NG) | 175-185 Emmensite, No.
1 Sample had been stored in | 167-184 magazine for some months in | a
wooden box. | " No. 2 Stored in tin case. | 165-177 " No. 5 " " | 205-217
__________________________________________________________|__
________ | | | °C. | Powder used in Chassepôt rifle | 191 | By Leygue &
Champion. French gunpowder | 295 | " " Rifle powder (picrate) | 358 | " "
Cannon | 380 | " "
__________________________________|_________|_________________
_______
Horsley's apparatus consists of an iron stand with a ring support, holding
a hemispherical iron vessel or bath in which solid paraffin is put. Above this
is another movable support, from which a thermometer is suspended, and so
adjusted that its bulb is immersed in the material contained in the iron
temperature should also be noted.
THE FIRING POINT OF VARIOUS EXPLOSIVES (by C. E. Munroe).
(Horsley's Apparatus used.)
___________________________________________________________
__________ | | °C. Nitro-glycerine, 5 years old (a single drop taken) | 203-
205 Gun-cotton (compressed military cotton, sp. gr. 1.5) | 192-201 Air-dried
gun-cotton, stored for 4 years | 179-187 Ditto, stored for 1 year | 187-189
Air-dried collodion-cotton, long staple "Red Island | cotton," 3 years old |
186-191 Air-dried collodion, 3 years old, stored wet | 197-199 Hydro-nitro-
cellulose | 201-213 Kieselguhr dynamite, No. 1 | 197-200 Explosive
gelatine | 203-209 Mercury fulminate | 175-181 Gunpowder (shell) | 278-
287 Hill's picric powder (shells) Been in store 10 years. | 273-283 Ditto
(musket) Composed of— | 282-290 Ammonium picrate 42.18 % |
Potassium picrate 53.79 " | Charcoal (alder) 3.85 " | ________ | | 99.82 |
Forcite, No. 1 | 187-200 Atlas powder (75% NG) | 175-185 Emmensite, No.
1 Sample had been stored in | 167-184 magazine for some months in | a
wooden box. | " No. 2 Stored in tin case. | 165-177 " No. 5 " " | 205-217
__________________________________________________________|__
________ | | | °C. | Powder used in Chassepôt rifle | 191 | By Leygue &
Champion. French gunpowder | 295 | " " Rifle powder (picrate) | 358 | " "
Cannon | 380 | " "
__________________________________|_________|_________________
_______
Horsley's apparatus consists of an iron stand with a ring support, holding
a hemispherical iron vessel or bath in which solid paraffin is put. Above this
is another movable support, from which a thermometer is suspended, and so
adjusted that its bulb is immersed in the material contained in the iron
Page 264
vessel. A thin copper cartridge-case, 5/8 inch in diameter and 1-15/16 inch
long, is suspended over the bath by means of a triangle, so that the end of
the case is just 1 inch below the surface of the molten material. On
beginning the experiment of determining the firing point of any explosive,
the material in the bath is heated to just above the melting point; the
thermometer is inserted in it, and a minute quantity of the explosive is
placed in the bottom of the cartridge-case. The initial temperature is noted,
and then the cartridge-case containing the explosive is inserted in the bath.
The temperature is quickly raised until the contents of the cartridge-case
flash off or explode, when the temperature is noted as the firing point.
[Illustration: FIG. 46.—HEAT TEST APPARATUS.]
Professor C.E. Munroe, of the U.S. Torpedo Station, has determined the
firing point of several explosives by means of this apparatus.
~The Government Heat Test (Explosives Act, 1875): Apparatus
required.~—A water bath, consisting of a spherical copper vessel (a), Fig.
46, of about 8 inches diameter, and with an aperture of about 5 inches; the
bath is filled with water to within a quarter of an inch of the edge. It has a
loose cover of sheet copper about 6 inches in diameter (b) and rests on a
tripod stand about 14 inches high (c), which is covered with coarse wire
gauze (e), and is surrounded with a screen of thin sheet copper (d). Within
the latter is placed an argand burner (f) with glass chimney. The cover (b)
has four holes arranged, as seen in Fig. II., No. 4 to contain a Page's[A] or
Scheibler's regulator, No. 3 the thermometer, Nos. 1 and 2 the test tubes
containing the explosive to be tested. Around the holes 1 and 2 on the under
side of the cover are soldered three pieces of brass wire with points slightly
converging (Fig. III.); these act as springs, and allow the test tubes to be
easily placed in position and removed.
[Footnote A: See Chem. Soc. Jour., 1876, i. 24. F.J.M. Page.]
long, is suspended over the bath by means of a triangle, so that the end of
the case is just 1 inch below the surface of the molten material. On
beginning the experiment of determining the firing point of any explosive,
the material in the bath is heated to just above the melting point; the
thermometer is inserted in it, and a minute quantity of the explosive is
placed in the bottom of the cartridge-case. The initial temperature is noted,
and then the cartridge-case containing the explosive is inserted in the bath.
The temperature is quickly raised until the contents of the cartridge-case
flash off or explode, when the temperature is noted as the firing point.
[Illustration: FIG. 46.—HEAT TEST APPARATUS.]
Professor C.E. Munroe, of the U.S. Torpedo Station, has determined the
firing point of several explosives by means of this apparatus.
~The Government Heat Test (Explosives Act, 1875): Apparatus
required.~—A water bath, consisting of a spherical copper vessel (a), Fig.
46, of about 8 inches diameter, and with an aperture of about 5 inches; the
bath is filled with water to within a quarter of an inch of the edge. It has a
loose cover of sheet copper about 6 inches in diameter (b) and rests on a
tripod stand about 14 inches high (c), which is covered with coarse wire
gauze (e), and is surrounded with a screen of thin sheet copper (d). Within
the latter is placed an argand burner (f) with glass chimney. The cover (b)
has four holes arranged, as seen in Fig. II., No. 4 to contain a Page's[A] or
Scheibler's regulator, No. 3 the thermometer, Nos. 1 and 2 the test tubes
containing the explosive to be tested. Around the holes 1 and 2 on the under
side of the cover are soldered three pieces of brass wire with points slightly
converging (Fig. III.); these act as springs, and allow the test tubes to be
easily placed in position and removed.
[Footnote A: See Chem. Soc. Jour., 1876, i. 24. F.J.M. Page.]
Page 265
~Test Tubes~, from 5-1/4 to 5-1/2 inches long, and of such a diameter
that they will hold from 20 to 22 cubic centimetres of water when filled to a
height of 5 inches; rather thick glass is preferable. Indiarubber stoppers,
fitting the test tubes, and carrying an arrangement for holding the test
papers, viz., a narrow glass tube passing through the centre of the stopper,
and terminating in a platinum wire hook. A glass rod drawn out and the end
turned up to form a hook is better.
~The Thermometer~ should have a range from 30° to 212° F., or from 1°
to 100° C. A minute clock is useful.
~Test Paper.~—The test paper is prepared as follows:—45 grains (2.9
grms.) of white maize starch (corn flour), previously washed with cold
water, are added to 8-1/2 oz. of water. The mixture is stirred, heated to
boiling, and kept gently boiling for ten minutes; 15 grains (1 grm.) of pure
potassium iodide (previously recrystallised from alcohol, absolutely
necessary) are dissolved in 8-1/2 oz. of distilled water. The two solutions
are thoroughly mixed and allowed to get cold. Strips or sheets of white
English filter paper, previously washed with water and re-dried, are dipped
into the solution thus prepared, and allowed to remain in it for not less than
ten seconds; they are then allowed to drain and dry in a place free from
laboratory fumes and dust. The upper and lower margins of the strips or
sheets are cut off, and the paper is preserved in well- stoppered or corked
bottles, and in the dark. The dimensions of the pieces of test paper used are
about 4/10 inch by 8/10 inch (10 mm. by 20 mm.).[A]
[Footnote A: When the paper is freshly prepared, and as long as it
remains in good condition, a drop of diluted acetic acid put on the paper
with a glass rod produces no coloration. In process of time it will become
brownish, when treated with the acid, especially if it has been exposed to
sunlight. It is then not fit for use.]
that they will hold from 20 to 22 cubic centimetres of water when filled to a
height of 5 inches; rather thick glass is preferable. Indiarubber stoppers,
fitting the test tubes, and carrying an arrangement for holding the test
papers, viz., a narrow glass tube passing through the centre of the stopper,
and terminating in a platinum wire hook. A glass rod drawn out and the end
turned up to form a hook is better.
~The Thermometer~ should have a range from 30° to 212° F., or from 1°
to 100° C. A minute clock is useful.
~Test Paper.~—The test paper is prepared as follows:—45 grains (2.9
grms.) of white maize starch (corn flour), previously washed with cold
water, are added to 8-1/2 oz. of water. The mixture is stirred, heated to
boiling, and kept gently boiling for ten minutes; 15 grains (1 grm.) of pure
potassium iodide (previously recrystallised from alcohol, absolutely
necessary) are dissolved in 8-1/2 oz. of distilled water. The two solutions
are thoroughly mixed and allowed to get cold. Strips or sheets of white
English filter paper, previously washed with water and re-dried, are dipped
into the solution thus prepared, and allowed to remain in it for not less than
ten seconds; they are then allowed to drain and dry in a place free from
laboratory fumes and dust. The upper and lower margins of the strips or
sheets are cut off, and the paper is preserved in well- stoppered or corked
bottles, and in the dark. The dimensions of the pieces of test paper used are
about 4/10 inch by 8/10 inch (10 mm. by 20 mm.).[A]
[Footnote A: When the paper is freshly prepared, and as long as it
remains in good condition, a drop of diluted acetic acid put on the paper
with a glass rod produces no coloration. In process of time it will become
brownish, when treated with the acid, especially if it has been exposed to
sunlight. It is then not fit for use.]
Page 266
In Germany zinc-iodide starch paper is used, which is considered to be
more sensitive than potassium iodide.
~Standard Tint Paper.~—A solution of caramel in water is made of such
concentration that when diluted one hundred times (10 c.c. made up to 1
litre) the tint of this diluted solution equals the tint produced by the Nessler
test in 100 c.c. water containing .000075 grm. of ammonia, or .00023505
grm. AmCl. With this caramel solution lines are drawn on strips of white
filter paper (previously well washed with distilled water, to remove traces
of bleaching matter, and dried) by means of a quill pen. When the marks
thus produced are dry, the paper is cut into pieces of the same size as the
test paper previously described, in such a way that each piece has a brown
line across it near the middle of its length, and only such strips are
preserved in which the brown line has a breadth varying from 1\2 mm. to 1
mm. (1/50 of an inch to 1/25 of an inch).
~Testing Dynamite, Blasting Gelatine, and Gelatine Dynamite.~—Nitro-
glycerine preparations, from which the nitro-glycerine can be extracted in
the manner described below, must satisfy the following test, otherwise they
will not be considered as manufactured with "thoroughly purified nitro-
glycerine," viz., fifteen minutes at 160° F. (72° C.).
~Apparatus required.~—A funnel 2 inches across (d), a cylindrical
measure divided into grains (e), Fig. 47.
~Mode of Operation.~—About 300 (19.4 grms.) to 400 grains (26 grms.)
of dynamite (b), finely divided, are placed in the funnel, which is loosely
plugged by freshly ignited asbestos (a). The surface is smoothed by means
of a flat-headed glass rod or stopper, and some clean washed and dried
kieselguhr (c) is spread over it to the depth of about 1/8 inch. Water is then
poured on from a wash bottle, and when the first portion has been soaked
up more is added; this is repeated until sufficient nitro- glycerine has
more sensitive than potassium iodide.
~Standard Tint Paper.~—A solution of caramel in water is made of such
concentration that when diluted one hundred times (10 c.c. made up to 1
litre) the tint of this diluted solution equals the tint produced by the Nessler
test in 100 c.c. water containing .000075 grm. of ammonia, or .00023505
grm. AmCl. With this caramel solution lines are drawn on strips of white
filter paper (previously well washed with distilled water, to remove traces
of bleaching matter, and dried) by means of a quill pen. When the marks
thus produced are dry, the paper is cut into pieces of the same size as the
test paper previously described, in such a way that each piece has a brown
line across it near the middle of its length, and only such strips are
preserved in which the brown line has a breadth varying from 1\2 mm. to 1
mm. (1/50 of an inch to 1/25 of an inch).
~Testing Dynamite, Blasting Gelatine, and Gelatine Dynamite.~—Nitro-
glycerine preparations, from which the nitro-glycerine can be extracted in
the manner described below, must satisfy the following test, otherwise they
will not be considered as manufactured with "thoroughly purified nitro-
glycerine," viz., fifteen minutes at 160° F. (72° C.).
~Apparatus required.~—A funnel 2 inches across (d), a cylindrical
measure divided into grains (e), Fig. 47.
~Mode of Operation.~—About 300 (19.4 grms.) to 400 grains (26 grms.)
of dynamite (b), finely divided, are placed in the funnel, which is loosely
plugged by freshly ignited asbestos (a). The surface is smoothed by means
of a flat-headed glass rod or stopper, and some clean washed and dried
kieselguhr (c) is spread over it to the depth of about 1/8 inch. Water is then
poured on from a wash bottle, and when the first portion has been soaked
up more is added; this is repeated until sufficient nitro- glycerine has
Page 267
collected in the graduated measure (e). If any water should have passed
through, it must be removed from the nitro-glycerine by filter paper, or the
nitro-glycerine may be filtered.
[Illustration: FIG. 47.—APPARATUS FOR SEPARATING THE NlTRO-
GLYCERINE FROM
DYNAMITE.]
[Illustration: FIG. 48.—TEST TUBE ARRANGED FOR HEAT TEST.]
~Application of Test.~—The thermometer is fixed so as to be inserted
through the lid of the water bath into the water, which is maintained at 160°
F. (72° C.), to a depth of 2-3/4 inches. Fifty grains (= 3.29 grms.) of nitro-
glycerine to be tested are weighed into the test tube, in such a way as not to
soil the sides of the tube (use a pipette). A test paper is fixed on the hook of
the glass rod, so that when inserted into the tube it will be in a vertical
position. A sufficient amount of a mixture of half distilled water and half
glycerine, to moisten the upper half of the paper, is now applied to the
upper edge of the test paper by means of a glass rod or camel's hair pencil;
the cork carrying the rod and paper is fixed into the test tube, and the
position of the paper adjusted so that its lower edge is about half way down
the tube; the latter is then inserted through one of the holes in the cover to
such a depth that the lower margin of the moistened part of the paper is
about 5/8 inch above the surface cover. The test is complete when the faint
brown line, which after a time makes its appearance at the line of boundary
between the dry and moist part of the paper, equals in tint the brown line of
the standard tint paper.
~Blasting Gelatine, Gelatine Dynamite, Gelignite, &c.~—Fifty grains (=
3.29 grms.) of blasting gelatine are intimately mixed with 100 grains (= 6.5
grms.) of French chalk. This is done by carefully working the two materials
together with a wooden pestle in a wooden mortar. The mixture is then
through, it must be removed from the nitro-glycerine by filter paper, or the
nitro-glycerine may be filtered.
[Illustration: FIG. 47.—APPARATUS FOR SEPARATING THE NlTRO-
GLYCERINE FROM
DYNAMITE.]
[Illustration: FIG. 48.—TEST TUBE ARRANGED FOR HEAT TEST.]
~Application of Test.~—The thermometer is fixed so as to be inserted
through the lid of the water bath into the water, which is maintained at 160°
F. (72° C.), to a depth of 2-3/4 inches. Fifty grains (= 3.29 grms.) of nitro-
glycerine to be tested are weighed into the test tube, in such a way as not to
soil the sides of the tube (use a pipette). A test paper is fixed on the hook of
the glass rod, so that when inserted into the tube it will be in a vertical
position. A sufficient amount of a mixture of half distilled water and half
glycerine, to moisten the upper half of the paper, is now applied to the
upper edge of the test paper by means of a glass rod or camel's hair pencil;
the cork carrying the rod and paper is fixed into the test tube, and the
position of the paper adjusted so that its lower edge is about half way down
the tube; the latter is then inserted through one of the holes in the cover to
such a depth that the lower margin of the moistened part of the paper is
about 5/8 inch above the surface cover. The test is complete when the faint
brown line, which after a time makes its appearance at the line of boundary
between the dry and moist part of the paper, equals in tint the brown line of
the standard tint paper.
~Blasting Gelatine, Gelatine Dynamite, Gelignite, &c.~—Fifty grains (=
3.29 grms.) of blasting gelatine are intimately mixed with 100 grains (= 6.5
grms.) of French chalk. This is done by carefully working the two materials
together with a wooden pestle in a wooden mortar. The mixture is then
Page 268
gradually introduced into the test tube, with the aid of gentle tapping upon
the table between the introduction of successive portions of the mixture into
the tube, so that when the tube contains all the mixture it shall be filled to
the extent of 1-3/4 inch of its height. The test paper is then inserted as above
described for nitro-glycerine. The sample tested must stand a temperature of
160° F. for a period of ten minutes before producing a discoloration of the
test paper corresponding in tint to the standard paper.
N.B.—Non-gelatinised nitro-glycerine preparations, from which the
nitro-glycerine cannot be expelled by water, are tested without any previous
separation of the ingredients, the temperature being as above 160° F., and
the time being seven minutes.
~Gun-Cotton, Schultze Gunpowder, E.C. Powder, &c.: A. Compressed
Gun- Cotton.~—Sufficient material to serve for two or more tests is
removed from the centre of the cartridge by gentle scraping, and if
necessary, further reduced by rubbing between the fingers. The fine powder
thus produced is spread out in a thin layer upon a paper tray 6 inches by 4-
1/2 inches, which is then placed inside a water oven, kept as nearly as
possible at 120° F. (49° C.). The wire gauze shelves of the oven should be
about 3 inches apart. The sample is allowed to remain at rest for fifteen
minutes in the oven, the door of which is left wide open. After the lapse of
fifteen minutes the tray is removed and exposed to the air of the room for
two hours, the sample being at some point within that time rubbed upon the
tray with the hand, in order to reduce it to a fine and uniform state of
division.
The heat test is performed as before, except that the temperature of the
bath is kept at 170° F. (66° C.), and regulator set to maintain that
temperature. Twenty grains (1.296 grm.) are used, placed in the test tube,
gently pressed down until it occupies a space of as nearly as possible 1-5/10
the table between the introduction of successive portions of the mixture into
the tube, so that when the tube contains all the mixture it shall be filled to
the extent of 1-3/4 inch of its height. The test paper is then inserted as above
described for nitro-glycerine. The sample tested must stand a temperature of
160° F. for a period of ten minutes before producing a discoloration of the
test paper corresponding in tint to the standard paper.
N.B.—Non-gelatinised nitro-glycerine preparations, from which the
nitro-glycerine cannot be expelled by water, are tested without any previous
separation of the ingredients, the temperature being as above 160° F., and
the time being seven minutes.
~Gun-Cotton, Schultze Gunpowder, E.C. Powder, &c.: A. Compressed
Gun- Cotton.~—Sufficient material to serve for two or more tests is
removed from the centre of the cartridge by gentle scraping, and if
necessary, further reduced by rubbing between the fingers. The fine powder
thus produced is spread out in a thin layer upon a paper tray 6 inches by 4-
1/2 inches, which is then placed inside a water oven, kept as nearly as
possible at 120° F. (49° C.). The wire gauze shelves of the oven should be
about 3 inches apart. The sample is allowed to remain at rest for fifteen
minutes in the oven, the door of which is left wide open. After the lapse of
fifteen minutes the tray is removed and exposed to the air of the room for
two hours, the sample being at some point within that time rubbed upon the
tray with the hand, in order to reduce it to a fine and uniform state of
division.
The heat test is performed as before, except that the temperature of the
bath is kept at 170° F. (66° C.), and regulator set to maintain that
temperature. Twenty grains (1.296 grm.) are used, placed in the test tube,
gently pressed down until it occupies a space of as nearly as possible 1-5/10
Page 269
inch in the test tube of dimensions previously specified. The fine cotton
adhering to the sides of the tube can be removed by a clean cloth or silk
handkerchief. The paper is moistened by touching the upper edge with a
drop of the 50 per cent. glycerine solution, the tube inserted in the bath to a
depth of 2-1/2 inches, measured from the cover, the regulator and
thermometer being inserted to the same depth. The test paper is to be kept
near the top of the test tube, but clear of the cork, until the tube has been
immersed for about five minutes. A ring of moisture will about this time be
deposited upon the sides of the test tube, a little above the cover of the bath.
The glass rod must then be lowered until the lower margin of the moistened
part of the paper is on a level with the bottom of the ring of moisture in the
tube. The paper is now closely watched, The test is complete when a very
faint brown coloration makes its appearance at the line of boundary
between the dry and moist parts of the paper. It must stand the test for not
less than ten minutes at 170° F. (The time is reckoned from the first
insertion of the tube in the bath until the appearance of a discoloration of
the test paper.)
~B. Schultze Powder, E.C. Powder, Collodion-Cotton, &c.~—The
sample is dried in the oven as above for fifteen minutes, and exposed for
two hours to the air. The test as above for compressed gun-cotton is then
applied.
~C. Cordite~ must stand a temperature of 180° F. for fifteen minutes. The
sample is prepared as follows:—Pieces half an inch long are cut from one
end of every stick selected for the test: in the case of the thicker cordites,
each piece so cut is further subdivided into about four portions. These cut
pieces are then passed once through the mill, the first portion of material
which passes through being rejected on account of the possible presence of
foreign matter from the mill. The ground material is put on the top sieve of
the nest of sieves, and sifted. That portion which has passed through the top
adhering to the sides of the tube can be removed by a clean cloth or silk
handkerchief. The paper is moistened by touching the upper edge with a
drop of the 50 per cent. glycerine solution, the tube inserted in the bath to a
depth of 2-1/2 inches, measured from the cover, the regulator and
thermometer being inserted to the same depth. The test paper is to be kept
near the top of the test tube, but clear of the cork, until the tube has been
immersed for about five minutes. A ring of moisture will about this time be
deposited upon the sides of the test tube, a little above the cover of the bath.
The glass rod must then be lowered until the lower margin of the moistened
part of the paper is on a level with the bottom of the ring of moisture in the
tube. The paper is now closely watched, The test is complete when a very
faint brown coloration makes its appearance at the line of boundary
between the dry and moist parts of the paper. It must stand the test for not
less than ten minutes at 170° F. (The time is reckoned from the first
insertion of the tube in the bath until the appearance of a discoloration of
the test paper.)
~B. Schultze Powder, E.C. Powder, Collodion-Cotton, &c.~—The
sample is dried in the oven as above for fifteen minutes, and exposed for
two hours to the air. The test as above for compressed gun-cotton is then
applied.
~C. Cordite~ must stand a temperature of 180° F. for fifteen minutes. The
sample is prepared as follows:—Pieces half an inch long are cut from one
end of every stick selected for the test: in the case of the thicker cordites,
each piece so cut is further subdivided into about four portions. These cut
pieces are then passed once through the mill, the first portion of material
which passes through being rejected on account of the possible presence of
foreign matter from the mill. The ground material is put on the top sieve of
the nest of sieves, and sifted. That portion which has passed through the top
Page 270
sieve and been stopped by the second is taken for the test. If the mill is
properly set, the greater portion of the ground material will be of the proper
size. If the volatile matter in the explosive exceeds 0.5 per cent., the sifted
material should be dried at a temperature not exceeding 140° F, until the
proportion does not exceed 0.5 per cent. After each sample has been
ground, the mill must be taken to pieces and carefully cleaned. The sieves
used consist of a nest of two sieves with holes drilled in sheet copper. The
holes in the top sieve have a diameter = 14 B.W.G., those in the second = 21
B.W.G.
If too hard for the mill, the cordite may be softened by exposure to the
vapour of acetone,[A] or reduced, to the necessary degree of subdivision by
means of a sharp moderately-coarse rasp. Should it have become too soft in
the acetone vapour for the mill, it should be cut up into small pieces, which
may be brought to any desired degree of hardness by simple exposure to air.
Explosives which consist partly of gelatinised collodion-cotton, and partly
of ungelatinised gun-cotton, are best reduced to powder by a rasp, or
softened by exposure to mixed ether and alcohol vapour at a temperature of
40° F. to 100° F.
[Footnote A: Mr W. Cullen (Jour. Soc. Chem. Ind., Jan. 31, 1901) says:—
"Undoubtedly the advent of the horny smokeless powders of modern times
has made it a little difficult to give the test the same scope as it had when
first introduced." As a rule a simple explanation can be found for every
apparently abnormal result, and in the accidental retention of a portion of
the solvent used in the manufacture, will frequently be found an explanation
of the trouble experienced.]
~Ballistite.~—In the case of ballistite the treatment is the same, except
that when it is in a very finely granulated condition it need not be cut up.
properly set, the greater portion of the ground material will be of the proper
size. If the volatile matter in the explosive exceeds 0.5 per cent., the sifted
material should be dried at a temperature not exceeding 140° F, until the
proportion does not exceed 0.5 per cent. After each sample has been
ground, the mill must be taken to pieces and carefully cleaned. The sieves
used consist of a nest of two sieves with holes drilled in sheet copper. The
holes in the top sieve have a diameter = 14 B.W.G., those in the second = 21
B.W.G.
If too hard for the mill, the cordite may be softened by exposure to the
vapour of acetone,[A] or reduced, to the necessary degree of subdivision by
means of a sharp moderately-coarse rasp. Should it have become too soft in
the acetone vapour for the mill, it should be cut up into small pieces, which
may be brought to any desired degree of hardness by simple exposure to air.
Explosives which consist partly of gelatinised collodion-cotton, and partly
of ungelatinised gun-cotton, are best reduced to powder by a rasp, or
softened by exposure to mixed ether and alcohol vapour at a temperature of
40° F. to 100° F.
[Footnote A: Mr W. Cullen (Jour. Soc. Chem. Ind., Jan. 31, 1901) says:—
"Undoubtedly the advent of the horny smokeless powders of modern times
has made it a little difficult to give the test the same scope as it had when
first introduced." As a rule a simple explanation can be found for every
apparently abnormal result, and in the accidental retention of a portion of
the solvent used in the manufacture, will frequently be found an explanation
of the trouble experienced.]
~Ballistite.~—In the case of ballistite the treatment is the same, except
that when it is in a very finely granulated condition it need not be cut up.
Page 271
~Guttmann's Heat Test.~—This test was proposed by Mr Oscar
Guttmann in a paper read before the Society of Chemical Industry (vol.
xvi., 1897), in the place of the potassium iodide starch paper used in the
Abel test. The filter paper used is wetted with a solution of
diphenylamine[A] in sulphuric acid. The solution is prepared as follows:—
Take 0.100 grm. of diphenylamine crystals, put them in a wide-necked flask
with a ground stopper, add 50 c.c. of dilute sulphuric acid (10 c.c. of
concentrated sulphuric acid to 40 c.c. of water), and put the flask in a water
bath at between 50° and 55° C. At this temperature the diphenylamine will
melt, and at once dissolve in the sulphuric acid, when the flask should be
taken out, well shaken, and allowed to cool. After cooling, add 50 c.c. of
Price's double distilled glycerine, shake well, and keep the solution in a
dark place. The test has to be applied in the following way:—The
explosives that have to be tested are finely subdivided, gun-cotton, nitro-
glycerine, dynamite, blasting gelatine, &c., in the same way as at present
directed by the Home Office regulations. Smokeless powders are all to be
ground in a bell-shaped coffee mill as finely as possible, and sifted as
hitherto. 1.5 grm. of the explosive (from the second sieve in the case of
smokeless powder) is to be weighed off and put into a test tube as hitherto
used. Strips of well-washed filter paper, 25 mm. wide, are to be hung on a
hooked glass rod as usual. A drop of the diphenylamine solution is taken up
by means of a clean glass rod, and the upper corners of the filter paper are
touched with it, so that when the two drops run together about a quarter of
the filter paper is moist. This is then put into the test tube, and this again
into the water bath, which has been heated to 70° C. The heat test reaction
should not show in a shorter time than fifteen minutes. It will begin by the
moist part of the paper acquiring a greenish yellow colour, and from this
moment the paper should be carefully watched. After one or two minutes a
dark blue mark will suddenly appear on the dividing line between the wet
and dry part of the filter paper, and this is the point that should be taken.
Guttmann in a paper read before the Society of Chemical Industry (vol.
xvi., 1897), in the place of the potassium iodide starch paper used in the
Abel test. The filter paper used is wetted with a solution of
diphenylamine[A] in sulphuric acid. The solution is prepared as follows:—
Take 0.100 grm. of diphenylamine crystals, put them in a wide-necked flask
with a ground stopper, add 50 c.c. of dilute sulphuric acid (10 c.c. of
concentrated sulphuric acid to 40 c.c. of water), and put the flask in a water
bath at between 50° and 55° C. At this temperature the diphenylamine will
melt, and at once dissolve in the sulphuric acid, when the flask should be
taken out, well shaken, and allowed to cool. After cooling, add 50 c.c. of
Price's double distilled glycerine, shake well, and keep the solution in a
dark place. The test has to be applied in the following way:—The
explosives that have to be tested are finely subdivided, gun-cotton, nitro-
glycerine, dynamite, blasting gelatine, &c., in the same way as at present
directed by the Home Office regulations. Smokeless powders are all to be
ground in a bell-shaped coffee mill as finely as possible, and sifted as
hitherto. 1.5 grm. of the explosive (from the second sieve in the case of
smokeless powder) is to be weighed off and put into a test tube as hitherto
used. Strips of well-washed filter paper, 25 mm. wide, are to be hung on a
hooked glass rod as usual. A drop of the diphenylamine solution is taken up
by means of a clean glass rod, and the upper corners of the filter paper are
touched with it, so that when the two drops run together about a quarter of
the filter paper is moist. This is then put into the test tube, and this again
into the water bath, which has been heated to 70° C. The heat test reaction
should not show in a shorter time than fifteen minutes. It will begin by the
moist part of the paper acquiring a greenish yellow colour, and from this
moment the paper should be carefully watched. After one or two minutes a
dark blue mark will suddenly appear on the dividing line between the wet
and dry part of the filter paper, and this is the point that should be taken.
Page 272
[Footnote A: Dr G. Spica (Rivista, Aug. 1897) proposes to use
hydrochloride of meta-phenylenediamine.]
~Exudation and Liquefaction Test for Blasting Gelatine, Gelatine
Dynamite, &c.~—A cylinder of blasting gelatine, &c., is to be cut from the
cartridge to be tested, the length of the cylinder to be equal to its diameter,
and the ends being cut flat. The cylinder is to be placed on end on a flat
surface without any wrapper, and secured by a pin passing vertically
through its centre. In this condition the cylinder is to be exposed for 144
consecutive hours (six days and nights) to a temperature ranging from 85°
to 90° F. (inclusive), and during such exposure the cylinder shall not
diminish in height by more than one-fourth of its original height, and the
upper cut surface shall retain its flatness and the sharpness of its edge.
~Exudation Test.~—There shall be no separation from the general mass
of the blasting gelatine or gelatine dynamite of a substance of less
consistency than the bulk of the remaining portion of the material under any
conditions of storage, transport, or use, or when the material is subjected
three times in succession to alternate freezing and thawing, or when
subjected to the liquefaction test before described.
~Picric Acid.~—The material shall contain not more than 0.3 part of
mineral or non-combustible matter in 100 parts by weight of the material
dried at 160° F. It should not contain more than a minute trace of lead. One
hundred parts of the dry material shall not contain more than 0.3 part of
total (free and combined) sulphuric acid, of which not more than 0.1 part
shall be free sulphuric acid. Its melting point should be between 248° and
253° F.
~Ammonite, Bellite, Roburite, and Explosives of similar Composition.~
— These are required to stand the same heat test as compressed nitro-
cellulose, gun-cotton, &c.
hydrochloride of meta-phenylenediamine.]
~Exudation and Liquefaction Test for Blasting Gelatine, Gelatine
Dynamite, &c.~—A cylinder of blasting gelatine, &c., is to be cut from the
cartridge to be tested, the length of the cylinder to be equal to its diameter,
and the ends being cut flat. The cylinder is to be placed on end on a flat
surface without any wrapper, and secured by a pin passing vertically
through its centre. In this condition the cylinder is to be exposed for 144
consecutive hours (six days and nights) to a temperature ranging from 85°
to 90° F. (inclusive), and during such exposure the cylinder shall not
diminish in height by more than one-fourth of its original height, and the
upper cut surface shall retain its flatness and the sharpness of its edge.
~Exudation Test.~—There shall be no separation from the general mass
of the blasting gelatine or gelatine dynamite of a substance of less
consistency than the bulk of the remaining portion of the material under any
conditions of storage, transport, or use, or when the material is subjected
three times in succession to alternate freezing and thawing, or when
subjected to the liquefaction test before described.
~Picric Acid.~—The material shall contain not more than 0.3 part of
mineral or non-combustible matter in 100 parts by weight of the material
dried at 160° F. It should not contain more than a minute trace of lead. One
hundred parts of the dry material shall not contain more than 0.3 part of
total (free and combined) sulphuric acid, of which not more than 0.1 part
shall be free sulphuric acid. Its melting point should be between 248° and
253° F.
~Ammonite, Bellite, Roburite, and Explosives of similar Composition.~
— These are required to stand the same heat test as compressed nitro-
cellulose, gun-cotton, &c.
Page 273
~Chlorate Mixtures.~—The material must not be too sensitive, and must
show no tendency to increase in sensitiveness in keeping. It must contain
nothing liable to reduce the chlorate. Chlorides calculated as potassium
chloride must not exceed 0.25 per cent. The material must contain no free
acid, or substance liable to produce free acid. Explosives of this class
containing nitro-compounds will be subject to the heat test.
~Page's Regulator.~—The most convenient gas regulator to use in
connection with the heat-test apparatus is the one invented by Prof. F.J.M.
Page, B.Sc.[A] (Fig. 49). It is not affected by variations of the barometric
pressure, and is simple and easy to fit up. It consists of a thermometer with
an elongated glass bulb 5/8 inch diameter and 3 inches long. The stem of
the thermometer is 5 inches long and 1/8 inch to 3/16 inch internal
diameter. One and a half inch from the top of the stem is fused in at right
angles a piece of glass tube, 1 inch long, of the same diameter as the stem,
so as to form a T. A piece of glass tube (A), about 7/16 inch external
diameter and 1-1/2 inch long, is fitted at one end with a short, sound cork
(C, Fig. 50). Through the centre of this cork a hole is bored, so that the stem
of the thermometer just fits into it. The other end of this glass tube is closed
by a tightly fitting cork, preferably of indiarubber (I), which is pierced by a
fine bradawl through the centre. Into the hole thus made is forced a piece of
fine glass tube (B) 3 inches long, and small enough to fit loosely inside the
stem of the thermometer.
[Footnote A: Chemical Soc. Jour., 1876, i. 24.]
The thermometer is filled by pouring in mercury through a small funnel
until the level of the mercury (when the thermometer is at the desired
temperature) is about 1-1/2 inch below the T. The piece of glass tube A,
closed at its upper extremity by the cork I, through which the fine glass tube
B passes into the stem of the thermometer, is now filled by means of the
show no tendency to increase in sensitiveness in keeping. It must contain
nothing liable to reduce the chlorate. Chlorides calculated as potassium
chloride must not exceed 0.25 per cent. The material must contain no free
acid, or substance liable to produce free acid. Explosives of this class
containing nitro-compounds will be subject to the heat test.
~Page's Regulator.~—The most convenient gas regulator to use in
connection with the heat-test apparatus is the one invented by Prof. F.J.M.
Page, B.Sc.[A] (Fig. 49). It is not affected by variations of the barometric
pressure, and is simple and easy to fit up. It consists of a thermometer with
an elongated glass bulb 5/8 inch diameter and 3 inches long. The stem of
the thermometer is 5 inches long and 1/8 inch to 3/16 inch internal
diameter. One and a half inch from the top of the stem is fused in at right
angles a piece of glass tube, 1 inch long, of the same diameter as the stem,
so as to form a T. A piece of glass tube (A), about 7/16 inch external
diameter and 1-1/2 inch long, is fitted at one end with a short, sound cork
(C, Fig. 50). Through the centre of this cork a hole is bored, so that the stem
of the thermometer just fits into it. The other end of this glass tube is closed
by a tightly fitting cork, preferably of indiarubber (I), which is pierced by a
fine bradawl through the centre. Into the hole thus made is forced a piece of
fine glass tube (B) 3 inches long, and small enough to fit loosely inside the
stem of the thermometer.
[Footnote A: Chemical Soc. Jour., 1876, i. 24.]
The thermometer is filled by pouring in mercury through a small funnel
until the level of the mercury (when the thermometer is at the desired
temperature) is about 1-1/2 inch below the T. The piece of glass tube A,
closed at its upper extremity by the cork I, through which the fine glass tube
B passes into the stem of the thermometer, is now filled by means of the
Page 274
perforated cork at its lower extremity on the stem of the thermometer. The
gas supply tube is attached to the top of the tube A, the burner to the T, so
that the gas passes in at the top, down the fine tube B, rises in the space
between B and the inside wall of the stem of the thermometer, and escapes
by the T. The regulator is set for any given temperature by pushing the cork
C, and consequently the tubes A and B, which are firmly attached to it, up
or down the stem of the thermometer, until the regulator just cuts off the gas
at the desired temperature.
[Illustration: FIG. 49.—PAGE'S REGULATOR.]
[Illustration: FIG. 50.—PAGE'S GAS REGULATOR, SHOWING BYE-
PASS AND
CUT-OFF ARRANGEMENT.]
As soon as the temperature falls, the mercury contracts, and thus opens
the end of the tube B. The gas is thus turned on, and the temperature rises
until the regulator again cuts off the gas. In order to prevent the possible
extinction of the flame by the regulator, the brass tube which carries the gas
to the regulator is connected with the tube which brings the gas from the
regulator to the burner by a small brass tap (Fig. 2). This tap forms an
adjustable bye-pass, and thus a small flame can be kept burning, even
though the regulator be completely shut off. It is obvious that the quantity
of gas supplied through the bye-pass must always be less than that required
to maintain the desired temperature. This regulator, placed in a beaker of
water on a tripod, will maintain the temperature of the water during four or
five hours within 0.2° C., and an air bath during six weeks within 0.5° C.
To sum up briefly the method of using the regulator:—Being filled with
mercury to about 1\2 inch below the T, attach the gas supply as in diagram
(Fig. 2), the brass tap being open, and the tube B unclosed by the mercury.
Allow the gas to completely expel the air in the apparatus. Push down the
gas supply tube is attached to the top of the tube A, the burner to the T, so
that the gas passes in at the top, down the fine tube B, rises in the space
between B and the inside wall of the stem of the thermometer, and escapes
by the T. The regulator is set for any given temperature by pushing the cork
C, and consequently the tubes A and B, which are firmly attached to it, up
or down the stem of the thermometer, until the regulator just cuts off the gas
at the desired temperature.
[Illustration: FIG. 49.—PAGE'S REGULATOR.]
[Illustration: FIG. 50.—PAGE'S GAS REGULATOR, SHOWING BYE-
PASS AND
CUT-OFF ARRANGEMENT.]
As soon as the temperature falls, the mercury contracts, and thus opens
the end of the tube B. The gas is thus turned on, and the temperature rises
until the regulator again cuts off the gas. In order to prevent the possible
extinction of the flame by the regulator, the brass tube which carries the gas
to the regulator is connected with the tube which brings the gas from the
regulator to the burner by a small brass tap (Fig. 2). This tap forms an
adjustable bye-pass, and thus a small flame can be kept burning, even
though the regulator be completely shut off. It is obvious that the quantity
of gas supplied through the bye-pass must always be less than that required
to maintain the desired temperature. This regulator, placed in a beaker of
water on a tripod, will maintain the temperature of the water during four or
five hours within 0.2° C., and an air bath during six weeks within 0.5° C.
To sum up briefly the method of using the regulator:—Being filled with
mercury to about 1\2 inch below the T, attach the gas supply as in diagram
(Fig. 2), the brass tap being open, and the tube B unclosed by the mercury.
Allow the gas to completely expel the air in the apparatus. Push down the
Page 275
tube A so that the end of B is well under the surface of the mercury. Turn off
the tap of the bye-pass until the smallest bead of flame is visible. Raise A
and B, and allow the temperature to rise until the desired point is attained.
Then push the tubes A and B slowly down until the flame is just shut off.
The regulator will then keep the temperature at that point.
~Will's Test for Nitro-Cellulose.~—The principle of Dr W. Will's test[A]
may be briefly described as follows:—The regularity with which nitro-
cellulose decomposes under conditions admitting of the removal of the
products of decomposition immediately following their formation is a
measure of its stability. As decomposing agent a sufficiently high
temperature (135° C.) is employed, the explosive being kept in a constantly
changing atmosphere of carbon dioxide, heated to the same temperature: the
oxides of nitrogen which result are swept over red-hot copper, and are then
reduced to nitrogen, and finally, the rates of evolution of nitrogen are
measured and compared. Dr Will considers that the best definition and test
of a stable nitro-cellulose is that it should give off at a high temperature
equal quantities of nitrogen in equal times. For the purposes of
manufacture, it is specially important that the material should be purified to
its limit, i.e., the point at which further washing produces no further change
in its speed of decomposition measured in the manner described.
[Footnote A: W. Will, Mitt. a. d. Centrallstelle f. Wissench. Techn.
Untersuchungen Nuo-Babelsberg Berlin, 1902 [2], 5-24.]
The sample of gun-cotton (2.5 grms.) is packed into the decomposition
tube 15 mm. wide and 10 cm. high, and heated by an oil bath to a constant
temperature, the oxides so produced are forced over ignited copper, where
they are reduced, and the nitrogen retained in the measuring tubes. Care
must be taken that the acid decomposition products do not condense in any
portion of the apparatus. The air in the whole apparatus is first displaced by
the tap of the bye-pass until the smallest bead of flame is visible. Raise A
and B, and allow the temperature to rise until the desired point is attained.
Then push the tubes A and B slowly down until the flame is just shut off.
The regulator will then keep the temperature at that point.
~Will's Test for Nitro-Cellulose.~—The principle of Dr W. Will's test[A]
may be briefly described as follows:—The regularity with which nitro-
cellulose decomposes under conditions admitting of the removal of the
products of decomposition immediately following their formation is a
measure of its stability. As decomposing agent a sufficiently high
temperature (135° C.) is employed, the explosive being kept in a constantly
changing atmosphere of carbon dioxide, heated to the same temperature: the
oxides of nitrogen which result are swept over red-hot copper, and are then
reduced to nitrogen, and finally, the rates of evolution of nitrogen are
measured and compared. Dr Will considers that the best definition and test
of a stable nitro-cellulose is that it should give off at a high temperature
equal quantities of nitrogen in equal times. For the purposes of
manufacture, it is specially important that the material should be purified to
its limit, i.e., the point at which further washing produces no further change
in its speed of decomposition measured in the manner described.
[Footnote A: W. Will, Mitt. a. d. Centrallstelle f. Wissench. Techn.
Untersuchungen Nuo-Babelsberg Berlin, 1902 [2], 5-24.]
The sample of gun-cotton (2.5 grms.) is packed into the decomposition
tube 15 mm. wide and 10 cm. high, and heated by an oil bath to a constant
temperature, the oxides so produced are forced over ignited copper, where
they are reduced, and the nitrogen retained in the measuring tubes. Care
must be taken that the acid decomposition products do not condense in any
portion of the apparatus. The air in the whole apparatus is first displaced by
Page 276
a stream of carbon dioxide issuing from a carbon dioxide generator, or gas-
holder, and passing through scrubbers, and this stream of gas is maintained
throughout the whole of the experiment, the gas being absorbed at the end
of the system by strong solution of caustic potash. To guard against the
danger of explosions, which occasionally occur, the decomposition tube and
oil bath are surrounded by a large casing with walls composed of iron plate
and strong glass.
Dr Will's apparatus has been modified by Dr Robertson,[A] of the Royal
Gunpowder Factory, Waltham Abbey. The form of the apparatus used by
him is shown in Fig. 51.
~CO_{2} Holders.~—Although objection has been taken to the use of
compressed CO_{2} in steel cylinders on account of the alleged large and
variable amount of air present, it has, nevertheless, been found possible to
obtain this gas with as little as 0.02 per cent. of air. Frequent estimations of
the air present in the CO_{2} of a cylinder show that even with the
commercial article, after the bulk of the CO_{2} has been removed, the
residual gas contains only a very small amount of air, which decreases in a
gradual and perfectly regular manner. For example, one cylinder which
gave 0.03 per cent. of air by volume, after three months' constant use gave
0.02 per cent. The advantage of using CO_{2} from this source is obvious
when compared with the difficulty of evolving a stream of gas of constant
composition from a Kipps or Finkener apparatus. A micrometer screw, in
addition to the main valve of the CO_{2} cylinder, is useful for governing
the rate of flow. A blank experiment should be made to ascertain the amount
of air in the CO_{2} and the correction made in the readings afterwards.
[Footnote A: Jour. Soc. Chem. Ind., June 30, 1902, p. 819.]
[Illustration: Fig 51.—Will's Apparatus for Testing Nitro-cellulose]
holder, and passing through scrubbers, and this stream of gas is maintained
throughout the whole of the experiment, the gas being absorbed at the end
of the system by strong solution of caustic potash. To guard against the
danger of explosions, which occasionally occur, the decomposition tube and
oil bath are surrounded by a large casing with walls composed of iron plate
and strong glass.
Dr Will's apparatus has been modified by Dr Robertson,[A] of the Royal
Gunpowder Factory, Waltham Abbey. The form of the apparatus used by
him is shown in Fig. 51.
~CO_{2} Holders.~—Although objection has been taken to the use of
compressed CO_{2} in steel cylinders on account of the alleged large and
variable amount of air present, it has, nevertheless, been found possible to
obtain this gas with as little as 0.02 per cent. of air. Frequent estimations of
the air present in the CO_{2} of a cylinder show that even with the
commercial article, after the bulk of the CO_{2} has been removed, the
residual gas contains only a very small amount of air, which decreases in a
gradual and perfectly regular manner. For example, one cylinder which
gave 0.03 per cent. of air by volume, after three months' constant use gave
0.02 per cent. The advantage of using CO_{2} from this source is obvious
when compared with the difficulty of evolving a stream of gas of constant
composition from a Kipps or Finkener apparatus. A micrometer screw, in
addition to the main valve of the CO_{2} cylinder, is useful for governing
the rate of flow. A blank experiment should be made to ascertain the amount
of air in the CO_{2} and the correction made in the readings afterwards.
[Footnote A: Jour. Soc. Chem. Ind., June 30, 1902, p. 819.]
[Illustration: Fig 51.—Will's Apparatus for Testing Nitro-cellulose]
Page 277
~Measurement of Pressure and Rate of Flow.~—Great attention is paid to
the measurement of the rate of flow of gas, which is arrived at by counting
with a stop-watch the number of bubbles of gas per minute in a small
sulphuric acid wash bottle. A mercury manometer is introduced here, and is
useful for detecting a leak in the apparatus. The rate of flow that gives the
most satisfactory results is 1,000 c.c. per hour. If too rapid it does not
become sufficiently preheated in the glass spiral, and if too slow there is a
more rapid decomposition of the nitro-cellulose by the oxides of nitrogen
which are not removed.
~Decomposition Tube.~—This is of the form and dimensions given by
Dr Will (15 mm. wide and 10 cm. high), the preheating worm being of the
thinnest hydrometer stem tubing. The ground-in exit tube is kept in position
by a small screw clamp with trunnion bearings.
~Bath.~—To permit of two experiments being carried on simultaneously,
the bath is adapted for two decomposition tubes, and is on the principle of
Lothar Meyer's air bath, that is, the bath proper filled with a high- flashing
hydrocarbon oil, and fitted with a lid perforated with two circular holes for
the spiral tubes, is surrounded by an asbestos-covered envelope, in the
interior of which circulate the products of combustion of numerous small
gas jets. The stirrer, agitated by a water motor, or, better still, a hot-air
engine, has a series of helical blades curved to give a thorough mixing to
the oil. Great uniformity and constancy of temperature are thus obtained.
The bath is fitted also with a temperature regulator and thermometer.
~Reduction Tube~—This is of copper, and consists of two parts, the
outer tube and an inner reaching to nearly the bottom of the former. Into the
inner tube fits a spiral of reduced copper gauze, and into the annular space
between the tubes is fitted a tightly packed reduced copper spiral. At the
bottom the inlet tube dips into a layer of copper oxide asbestos, on the top
the measurement of the rate of flow of gas, which is arrived at by counting
with a stop-watch the number of bubbles of gas per minute in a small
sulphuric acid wash bottle. A mercury manometer is introduced here, and is
useful for detecting a leak in the apparatus. The rate of flow that gives the
most satisfactory results is 1,000 c.c. per hour. If too rapid it does not
become sufficiently preheated in the glass spiral, and if too slow there is a
more rapid decomposition of the nitro-cellulose by the oxides of nitrogen
which are not removed.
~Decomposition Tube.~—This is of the form and dimensions given by
Dr Will (15 mm. wide and 10 cm. high), the preheating worm being of the
thinnest hydrometer stem tubing. The ground-in exit tube is kept in position
by a small screw clamp with trunnion bearings.
~Bath.~—To permit of two experiments being carried on simultaneously,
the bath is adapted for two decomposition tubes, and is on the principle of
Lothar Meyer's air bath, that is, the bath proper filled with a high- flashing
hydrocarbon oil, and fitted with a lid perforated with two circular holes for
the spiral tubes, is surrounded by an asbestos-covered envelope, in the
interior of which circulate the products of combustion of numerous small
gas jets. The stirrer, agitated by a water motor, or, better still, a hot-air
engine, has a series of helical blades curved to give a thorough mixing to
the oil. Great uniformity and constancy of temperature are thus obtained.
The bath is fitted also with a temperature regulator and thermometer.
~Reduction Tube~—This is of copper, and consists of two parts, the
outer tube and an inner reaching to nearly the bottom of the former. Into the
inner tube fits a spiral of reduced copper gauze, and into the annular space
between the tubes is fitted a tightly packed reduced copper spiral. At the
bottom the inlet tube dips into a layer of copper oxide asbestos, on the top
Page 278
of which is a layer of reduced copper asbestos. Through the indiarubber
cork passes a glass tube, which leads the CO_{2} and nitrogen out of the
reduction tube. As the portion of the tube containing the spirals is heated to
redness, water jackets are provided on both inner and outer tubes to protect
the indiarubber cork.
~Nitrogen Measuring Apparatus.~—The measuring tube with zigzag
arrangement is used, having been found very economical in potash. It is
most convenient to take readings by counterbalancing the column of potash
solution and reading off the volume of gas at atmospheric pressure. For this
purpose the tap immediately in front of the measuring tube is momentarily
closed, this having been proved to be without ill effect on the progress of
the test. In all experiments done by this test the air correction is subtracted
from each reading, and the remainder brought to milligrams of nitrogen
with the usual corrections. As objection has frequently been taken to the test
on the ground of difficulty in interpreting the results obtained, Dr Robertson
made a series of experiments for the purpose of standardising the test, and
at the same time of arriving at the condition under which it could be applied
in the most sensitive and efficient manner. A variety of nitro-celluloses
having been tested, there were chosen as typical, of stable and unstable
products, service gun-cotton on the one hand, and an experimental gun-
cotton, Z, on the other. The first point brought out by these experiments was
the striking uniformity of service gun-cotton, first in regard to the
rectilinear nature of the curve of evolution of nitrogen, and secondly in
regard to the small range within which a large number of results is included,
15 samples lying between 6.6 and 8.7 mgms. of nitrogen evolved in four
hours. In the case of service gun-cotton, little difference in the rate of
evolution of nitrogen evolved is obtained on altering the rate of passage of
CO_{2} gas through the wide range of 500 c.c. per hour to 2,500 c.c. per
hour. With Z gun-cotton (see Fig. 52), however, the case is very different.
Operating at a rate of 1,000 c.c. of CO_{2} per hour, a curve of nitrogen
cork passes a glass tube, which leads the CO_{2} and nitrogen out of the
reduction tube. As the portion of the tube containing the spirals is heated to
redness, water jackets are provided on both inner and outer tubes to protect
the indiarubber cork.
~Nitrogen Measuring Apparatus.~—The measuring tube with zigzag
arrangement is used, having been found very economical in potash. It is
most convenient to take readings by counterbalancing the column of potash
solution and reading off the volume of gas at atmospheric pressure. For this
purpose the tap immediately in front of the measuring tube is momentarily
closed, this having been proved to be without ill effect on the progress of
the test. In all experiments done by this test the air correction is subtracted
from each reading, and the remainder brought to milligrams of nitrogen
with the usual corrections. As objection has frequently been taken to the test
on the ground of difficulty in interpreting the results obtained, Dr Robertson
made a series of experiments for the purpose of standardising the test, and
at the same time of arriving at the condition under which it could be applied
in the most sensitive and efficient manner. A variety of nitro-celluloses
having been tested, there were chosen as typical, of stable and unstable
products, service gun-cotton on the one hand, and an experimental gun-
cotton, Z, on the other. The first point brought out by these experiments was
the striking uniformity of service gun-cotton, first in regard to the
rectilinear nature of the curve of evolution of nitrogen, and secondly in
regard to the small range within which a large number of results is included,
15 samples lying between 6.6 and 8.7 mgms. of nitrogen evolved in four
hours. In the case of service gun-cotton, little difference in the rate of
evolution of nitrogen evolved is obtained on altering the rate of passage of
CO_{2} gas through the wide range of 500 c.c. per hour to 2,500 c.c. per
hour. With Z gun-cotton (see Fig. 52), however, the case is very different.
Operating at a rate of 1,000 c.c. of CO_{2} per hour, a curve of nitrogen
Page 279
evolution is obtained, which is bent and forms a good representation of the
inherent instability of the material as proved to exist from other
considerations. Operating at the rate of 1,500 c.c. per hour, as recommended
by Dr Will, the evolution of nitrogen is represented by a straight line,
steeper, however, than that of service gun-cotton. The rate of passage of
CO_{2} was therefore chosen at 1,000 c.c. per hour, or two-thirds of the
rate of Dr Will, and this rate, besides possessing the advantage claimed of
rendering diagnostic the manner of nitrogen evolution in Z gun-cotton, has
in other cases been useful in bringing out relationships, which the higher
rate would have entirely masked.
[Illustration: Fig. 52.—Dr. Robertson's results.]
[Illustration: Fig. 53.—Service Guncotton for Cordite made at a Private
Factory.]
Readings are taken thirty minutes from the time the nitro-cellulose is
heated, and are taken at intervals of fifteen minutes for about four hours;
fresh caustic potash is added every thirty minutes or so. It is convenient to
plot the results in curves. The curves given in Fig. 53 are from gun-cotton
manufacturers in England at a private factory. The rate of evolution of
nitrogen is as follows:—
In 1 hour. In 2 hours. In 3 hours. In 4 hours. N. N. N. N. in milligrammes.
1.25 2.55 4.5 5.75 1.5 3.25 5.25 6.75 These results are very satisfactory, the
gun-cotton was of a very good quality. Several hours are necessary to
remove all the air from the apparatus. Dr Will stated fifteen minutes in his
original paper, but this has not been found sufficient. It has not been
satisfactorily proved that Will's test can be applied to gelatinised nitro-
cellulose powders. It is convenient to plot the results in curves; the nitrogen
is generally given in cubic centimetres or in milligrammes, and readings
taken every fifteen minutes. The steepness of the curve is a measure of the
inherent instability of the material as proved to exist from other
considerations. Operating at the rate of 1,500 c.c. per hour, as recommended
by Dr Will, the evolution of nitrogen is represented by a straight line,
steeper, however, than that of service gun-cotton. The rate of passage of
CO_{2} was therefore chosen at 1,000 c.c. per hour, or two-thirds of the
rate of Dr Will, and this rate, besides possessing the advantage claimed of
rendering diagnostic the manner of nitrogen evolution in Z gun-cotton, has
in other cases been useful in bringing out relationships, which the higher
rate would have entirely masked.
[Illustration: Fig. 52.—Dr. Robertson's results.]
[Illustration: Fig. 53.—Service Guncotton for Cordite made at a Private
Factory.]
Readings are taken thirty minutes from the time the nitro-cellulose is
heated, and are taken at intervals of fifteen minutes for about four hours;
fresh caustic potash is added every thirty minutes or so. It is convenient to
plot the results in curves. The curves given in Fig. 53 are from gun-cotton
manufacturers in England at a private factory. The rate of evolution of
nitrogen is as follows:—
In 1 hour. In 2 hours. In 3 hours. In 4 hours. N. N. N. N. in milligrammes.
1.25 2.55 4.5 5.75 1.5 3.25 5.25 6.75 These results are very satisfactory, the
gun-cotton was of a very good quality. Several hours are necessary to
remove all the air from the apparatus. Dr Will stated fifteen minutes in his
original paper, but this has not been found sufficient. It has not been
satisfactorily proved that Will's test can be applied to gelatinised nitro-
cellulose powders. It is convenient to plot the results in curves; the nitrogen
is generally given in cubic centimetres or in milligrammes, and readings
taken every fifteen minutes. The steepness of the curve is a measure of the
Page 280
stability of the nitro-cellulose which is being examined. The steeper the
curve the more nitrogen is evolved per unit of time, and the less stable the
nitro- cellulose. In the case of unstable nitro-celluloses heated under the
conditions described, the separation of nitrogen is much greater at first than
at a later period. If the nitro-cellulose be very unstable, explosions are
produced. If the separation of nitrogen is uniform during the prolonged
heating, then the nitro-cellulose may be regarded as "normal." If it be
desired to determine the absolute amount of nitrogen separated from a nitro-
cellulose, the following conditions must be observed:—(1.) Accurate
weighing of the nitro-cellulose; (2.) Determination of the amount of air in
the CO_{2}, and deduction of this from the volume of gas obtained; (3.)
Reduction of the volume of the gas to the volume at 0° C. and 760 mm.
pressure.[A]
[Footnote A: See also Jour. Soc. Chem. Ind., Dec. 1902, pages 1545-
1555, on the "Stability of Nitro-cellulose" and "Examination of Nitro-
cellulose," Dr Will.]
~Bergrnann and Junk~[A] describe a test for nitro-cellulose that has been
in use in the Prussian testing station for some years. The apparatus consists
of a closed copper bath provided with a condenser and 10 countersunk
tubes of 20 cm. length. By boiling amyl-alcohol in the bath, the tubes can
be kept at a constant temperature of 132° C. The explosive to be tested is
placed in a glass tube 35 cm. long and 2 cm. wide, having a ground neck
into which an absorption bulb is fitted. The whole apparatus is surrounded
by a shield, in case of explosion. In carrying out the test, 2 grms. of the
explosive are placed in the glass tube and well pressed down. The
absorption bulb is half filled with water, and fitted into the ground neck of
the glass tube, which is then placed in one of the tubes in the bath
previously brought to the boiling point (132° C.). The evolved oxides of
nitrogen are absorbed in the water in the bulb, and at the end of two hours
curve the more nitrogen is evolved per unit of time, and the less stable the
nitro- cellulose. In the case of unstable nitro-celluloses heated under the
conditions described, the separation of nitrogen is much greater at first than
at a later period. If the nitro-cellulose be very unstable, explosions are
produced. If the separation of nitrogen is uniform during the prolonged
heating, then the nitro-cellulose may be regarded as "normal." If it be
desired to determine the absolute amount of nitrogen separated from a nitro-
cellulose, the following conditions must be observed:—(1.) Accurate
weighing of the nitro-cellulose; (2.) Determination of the amount of air in
the CO_{2}, and deduction of this from the volume of gas obtained; (3.)
Reduction of the volume of the gas to the volume at 0° C. and 760 mm.
pressure.[A]
[Footnote A: See also Jour. Soc. Chem. Ind., Dec. 1902, pages 1545-
1555, on the "Stability of Nitro-cellulose" and "Examination of Nitro-
cellulose," Dr Will.]
~Bergrnann and Junk~[A] describe a test for nitro-cellulose that has been
in use in the Prussian testing station for some years. The apparatus consists
of a closed copper bath provided with a condenser and 10 countersunk
tubes of 20 cm. length. By boiling amyl-alcohol in the bath, the tubes can
be kept at a constant temperature of 132° C. The explosive to be tested is
placed in a glass tube 35 cm. long and 2 cm. wide, having a ground neck
into which an absorption bulb is fitted. The whole apparatus is surrounded
by a shield, in case of explosion. In carrying out the test, 2 grms. of the
explosive are placed in the glass tube and well pressed down. The
absorption bulb is half filled with water, and fitted into the ground neck of
the glass tube, which is then placed in one of the tubes in the bath
previously brought to the boiling point (132° C.). The evolved oxides of
nitrogen are absorbed in the water in the bulb, and at the end of two hours
Page 281
the tubes are removed from the bath, and on cooling, the water from the
bulb flows back and wets the explosive. The contents of the tube are filtered
and washed, the filtrate is oxidised with permanganate, and the nitrogen
determined as nitric oxide by the Schultze-Tieman method. The authors
conclude that a stable gun-cotton does not evolve more than 2.5 c.c. of
nitric oxide per grm. on being heated to 132° C. for two hours, and a stable
collodion-cotton not more than 2 c.c. under the same conditions. The
percentage of moisture in the sample to be tested should be kept as low as
possible. A sample of nitro-cellulose containing 1.97% of moisture gave an
evolution of 2.6 c.c. per grm., while the same sample with 3.4% moisture
gave an evolution of over 50 c.c. per grm. Sodium carbonate added to an
unstable nitro-cellulose diminishes the rate of decomposition, but if sodium
carbonate be intimately mixed with a stable nitro-cellulose the rate of
decomposition will be increased. Calcium carbonate and mercury chloride
have no influence. If an unstable nitro- cellulose be extracted with alcohol a
stable compound is produced. The percentage solubility of a nitro-cellulose
in ether-alcohol rises on heating to 132° C. A sample which before heating
had a solubility of 4.7% had its solubility increased to 82.5% after six
hours' heating.
[Footnote A: Jour. Soc. Chem. Ind., xxiii., Oct. 15, 1904, p. 953.]
Mr A.P. Sy (Jour. Amer. Chem. Soc., 1903) describes a new stability test
for nitro-cellulose which he terms "The Elastic Limit of Powder Resistance
to Heat." The test consists in heating the powder on a watch glass in an
oven to a temperature of 115° C., after eight hours the watch glass and
powder are weighed and the process repeated daily for six days or less. He
claims that the powder is tested in its natural state, all the products of
decomposition are taken into account, whilst in the old tests only the acid
products are shown, and in the Will test only nitrogen, that it affords an
indication of the effect of small quantities of added substances or foreign
bulb flows back and wets the explosive. The contents of the tube are filtered
and washed, the filtrate is oxidised with permanganate, and the nitrogen
determined as nitric oxide by the Schultze-Tieman method. The authors
conclude that a stable gun-cotton does not evolve more than 2.5 c.c. of
nitric oxide per grm. on being heated to 132° C. for two hours, and a stable
collodion-cotton not more than 2 c.c. under the same conditions. The
percentage of moisture in the sample to be tested should be kept as low as
possible. A sample of nitro-cellulose containing 1.97% of moisture gave an
evolution of 2.6 c.c. per grm., while the same sample with 3.4% moisture
gave an evolution of over 50 c.c. per grm. Sodium carbonate added to an
unstable nitro-cellulose diminishes the rate of decomposition, but if sodium
carbonate be intimately mixed with a stable nitro-cellulose the rate of
decomposition will be increased. Calcium carbonate and mercury chloride
have no influence. If an unstable nitro- cellulose be extracted with alcohol a
stable compound is produced. The percentage solubility of a nitro-cellulose
in ether-alcohol rises on heating to 132° C. A sample which before heating
had a solubility of 4.7% had its solubility increased to 82.5% after six
hours' heating.
[Footnote A: Jour. Soc. Chem. Ind., xxiii., Oct. 15, 1904, p. 953.]
Mr A.P. Sy (Jour. Amer. Chem. Soc., 1903) describes a new stability test
for nitro-cellulose which he terms "The Elastic Limit of Powder Resistance
to Heat." The test consists in heating the powder on a watch glass in an
oven to a temperature of 115° C., after eight hours the watch glass and
powder are weighed and the process repeated daily for six days or less. He
claims that the powder is tested in its natural state, all the products of
decomposition are taken into account, whilst in the old tests only the acid
products are shown, and in the Will test only nitrogen, that it affords an
indication of the effect of small quantities of added substances or foreign
Page 282
matters on the stability and that it is simple, and not subject to the variations
of the old tests.
Obermüller (Jour. Soc. Chem. Ind., April 15, 1905) considers Bergmann
and Junk's test is too complicated and occupies too much time; he proposes
to heat gun-cotton to 140° C. in vacuo, and to measure continuously by
means of a mercury manometer the pressure exerted by the evolved gases,
the latter being maintained at constant volume; the rate at which the
pressure increases is a measure of the rate of decomposition of the nitro-
cellulose.
SPECIFIC GRAVITIES OF EXPLOSIVES, &C.
Nitro-glycerine 1.6
Gun-cotton (dry) 1.06
" (25 per cent. water) 1.32
Dynamite No. 1 1.62
Blasting gelatine 1.54
Gelatine dynamite 1.55
Ballistite 1.6
Forcite 1.51
Tonite 1.28
Roburite 1.40
Bellite 1.2-1.4
Carbo-dynamite 1.5
Turpin's cast picric acid 1.6
Nitro-mannite 1.6
Nitro-starch 1.5
Emmensite 1.8
Mono-nitro-benzene 1.2
Meta-di-nitro-benzene 1.575 at 18° C.
of the old tests.
Obermüller (Jour. Soc. Chem. Ind., April 15, 1905) considers Bergmann
and Junk's test is too complicated and occupies too much time; he proposes
to heat gun-cotton to 140° C. in vacuo, and to measure continuously by
means of a mercury manometer the pressure exerted by the evolved gases,
the latter being maintained at constant volume; the rate at which the
pressure increases is a measure of the rate of decomposition of the nitro-
cellulose.
SPECIFIC GRAVITIES OF EXPLOSIVES, &C.
Nitro-glycerine 1.6
Gun-cotton (dry) 1.06
" (25 per cent. water) 1.32
Dynamite No. 1 1.62
Blasting gelatine 1.54
Gelatine dynamite 1.55
Ballistite 1.6
Forcite 1.51
Tonite 1.28
Roburite 1.40
Bellite 1.2-1.4
Carbo-dynamite 1.5
Turpin's cast picric acid 1.6
Nitro-mannite 1.6
Nitro-starch 1.5
Emmensite 1.8
Mono-nitro-benzene 1.2
Meta-di-nitro-benzene 1.575 at 18° C.
Page 283
Ortho-di-nitro-benzene 1.590 "
Para-di-nitro-benzene 1.625 "
British gunpowder, E.X.E. 1.80
" " S.B.C. 1.85
Cannonite (powder) 1.60
Celluloid 1.35
Cellulose 1.45
Ammonium nitrate 1.707
Mercury fulminate 4.42
TABLE OF THE TEMPERATURE OF DETONATION.
Blasting gelatine 3220°
Nitro-glycerine 3170°
Dynamite 2940°
Gun-cotton 2650°
Tonite 2648°
Picric acid 2620°
Roburite 2100°
Ammonia nitrate 1130°
RELATIVE SENSITIVENESS TO DETONATION (by Professor C.E.
Munroe, U.S. Naval
Torpedo Station).
___________________________________________________________
_______________ | | Maximum | | Distance | | at which | | Detonation | |
occurred. | | CM. | | | Gun-cotton | 10 | Nitro-glycerine 86.5 nitro-cotton | |
9.5, camphor 4 per cent. Explosive gelatine | 20 | NH_{4}NO_{3} 5 parts,
(camphorated) | | C_{6}H_{4}(N0_{3}){2} 1 part. Judson powder, R.R.P. |
25 | Emmensite (No. 259) | 30 | Rack-a-rock | 32 | KClO{3} 79 parts, | |
C_{6}H_{5}(NO)_{2} 21 parts. Bellite | 50 | Forcite No. 1 | 61 | Kieselguhr
Para-di-nitro-benzene 1.625 "
British gunpowder, E.X.E. 1.80
" " S.B.C. 1.85
Cannonite (powder) 1.60
Celluloid 1.35
Cellulose 1.45
Ammonium nitrate 1.707
Mercury fulminate 4.42
TABLE OF THE TEMPERATURE OF DETONATION.
Blasting gelatine 3220°
Nitro-glycerine 3170°
Dynamite 2940°
Gun-cotton 2650°
Tonite 2648°
Picric acid 2620°
Roburite 2100°
Ammonia nitrate 1130°
RELATIVE SENSITIVENESS TO DETONATION (by Professor C.E.
Munroe, U.S. Naval
Torpedo Station).
___________________________________________________________
_______________ | | Maximum | | Distance | | at which | | Detonation | |
occurred. | | CM. | | | Gun-cotton | 10 | Nitro-glycerine 86.5 nitro-cotton | |
9.5, camphor 4 per cent. Explosive gelatine | 20 | NH_{4}NO_{3} 5 parts,
(camphorated) | | C_{6}H_{4}(N0_{3}){2} 1 part. Judson powder, R.R.P. |
25 | Emmensite (No. 259) | 30 | Rack-a-rock | 32 | KClO{3} 79 parts, | |
C_{6}H_{5}(NO)_{2} 21 parts. Bellite | 50 | Forcite No. 1 | 61 | Kieselguhr
Page 284
dynamite No. 1 | 64 | 75 per cent. nitro-gycerine. Atlas powder No. 1 | 74 |
__________________________|____________|______________________
___
CHAPTER IX.
DETERMINATION OF THE RELATIVE STRENGTH OF EXPLOSIVES.
Effectiveness of an Explosive—High and Low Explosives—Theoretical
Efficiency—MM. Roux and Sarrau's Results—Abel and Noble's—Nobel's
Ballistic Test—The Mortar, Pressure, or Crusher Gauge—Lead Cylinders—
The Foot-Pounds Machine—Noble's Pressure Gauge—Lieutenant Walke's
Results—Calculation of Pressure Developed by Dynamite and Gun-Cotton
—
Macnab's and Ristori's Results of Heat Developed by the Explosion of
Various Explosives—Composition of some of the Explosives in Common
Use
for Blasting, &c.
~The Determination of the Relative Strength of Explosives.~—
Explosives may be roughly divided into two divisions, viz., those which
when exploded produce a shattering force, and those which produce a
propulsive force. Explosives of the first class are generally known as the
high explosives, and consist for the most part of nitro compounds, or
mixtures of nitro compounds with other substances. Any explosive whose
detonation is very rapid is a high explosive, but the term has chiefly been
applied to the nitro-explosives.
__________________________|____________|______________________
___
CHAPTER IX.
DETERMINATION OF THE RELATIVE STRENGTH OF EXPLOSIVES.
Effectiveness of an Explosive—High and Low Explosives—Theoretical
Efficiency—MM. Roux and Sarrau's Results—Abel and Noble's—Nobel's
Ballistic Test—The Mortar, Pressure, or Crusher Gauge—Lead Cylinders—
The Foot-Pounds Machine—Noble's Pressure Gauge—Lieutenant Walke's
Results—Calculation of Pressure Developed by Dynamite and Gun-Cotton
—
Macnab's and Ristori's Results of Heat Developed by the Explosion of
Various Explosives—Composition of some of the Explosives in Common
Use
for Blasting, &c.
~The Determination of the Relative Strength of Explosives.~—
Explosives may be roughly divided into two divisions, viz., those which
when exploded produce a shattering force, and those which produce a
propulsive force. Explosives of the first class are generally known as the
high explosives, and consist for the most part of nitro compounds, or
mixtures of nitro compounds with other substances. Any explosive whose
detonation is very rapid is a high explosive, but the term has chiefly been
applied to the nitro-explosives.
Page 285
The effectiveness of an explosive depends upon the volume and
temperature of the gases formed, and upon the rapidity of the explosion. In
the high explosives the chemical transformation is very rapid, hence they
exert a crushing of shattering effect. Gunpowder, on the other hand, is a low
explosive, and produces a propelling or heaving effect.
The maximum work that an explosive is capable of producing is
proportionate to the amount of heat disengaged during its chemical
transformation. This may be expressed in kilogrammetres by the formula
425Q, where Q is the number of units of heat evolved. The theoretical
efficiency of an explosive cannot, however, be expected in practice for
many reasons.
In the case of blasting rock, for instance:[A]—1. Incomplete combustion
of the explosive. 2. Compression and chemical changes induced in the
surrounding material operated on. 3. Energy expended in the cracking and
heating of the material which is not displaced. 4. The escape of gas through
the blast-hole, and the fissures caused by the explosion. The proportion of
useful work has been estimated to be from 14 to 33 per cent. of the
theoretical maximum potential.
[Footnote A: C.N. Hake, Government Inspector of Explosives, Victoria,
Jour. Soc. Chem. Ind., 1889.]
For the purposes of comparison, manufacturers generally rely more upon
the practical than the theoretical efficiency of an explosive. These, however,
stand in the same relation to one another, as the following table of Messrs
Roux and Sarrau will show:—
MECHANICAL EQUIVALENT OF EXPLOSIVES.
temperature of the gases formed, and upon the rapidity of the explosion. In
the high explosives the chemical transformation is very rapid, hence they
exert a crushing of shattering effect. Gunpowder, on the other hand, is a low
explosive, and produces a propelling or heaving effect.
The maximum work that an explosive is capable of producing is
proportionate to the amount of heat disengaged during its chemical
transformation. This may be expressed in kilogrammetres by the formula
425Q, where Q is the number of units of heat evolved. The theoretical
efficiency of an explosive cannot, however, be expected in practice for
many reasons.
In the case of blasting rock, for instance:[A]—1. Incomplete combustion
of the explosive. 2. Compression and chemical changes induced in the
surrounding material operated on. 3. Energy expended in the cracking and
heating of the material which is not displaced. 4. The escape of gas through
the blast-hole, and the fissures caused by the explosion. The proportion of
useful work has been estimated to be from 14 to 33 per cent. of the
theoretical maximum potential.
[Footnote A: C.N. Hake, Government Inspector of Explosives, Victoria,
Jour. Soc. Chem. Ind., 1889.]
For the purposes of comparison, manufacturers generally rely more upon
the practical than the theoretical efficiency of an explosive. These, however,
stand in the same relation to one another, as the following table of Messrs
Roux and Sarrau will show:—
MECHANICAL EQUIVALENT OF EXPLOSIVES.
Page 286
Theoretical Work Relative
in Kilos. Value.
Blasting powder (62 per cent. KNO_{3}) 242,335 1.0
Dynamite (75 per cent. nitro-glycerine) 548,250 2.26
Blasting gelatine (92 per cent. nitro-glycerine) 766,813 3.16
Nitro-glycerine 794,563 3.28
Experiments made in lead cylinders give—
Dynamite 1.0
Blasting gelatine 1.4
Nitro-glycerine 1.4
Sir Frederick Abel and Captain W.H. Noble, R.A., have shown that the
maximum pressure exerted by gunpowder is equal to 486 foot-tons per lb.
of powder, or that when 1 kilo, of the powder gases occupy the volume of 1
litre, the pressure is equal to 6,400 atmospheres; and Berthelot has
calculated that every gramme of nitro-glycerine exploded gives 1,320 units
of heat. MM. Roux and Sarrau, of the Depôt Centrales des Poudres, Paris,
by means of calorimetric determinations, have shown that the following
units of heat are produced by the detonation of—
Nitro-glycerine 1,784 heat units.
Gun-cotton 1,123 "
Potassic picrate 840 "
which, multiplied by the mechanical equivalent per unit, gives—
Nitro-glycerine 778 metre tons per kilogramme.
Gun-cotton 489 " "
Picrate of potash 366 " "
in Kilos. Value.
Blasting powder (62 per cent. KNO_{3}) 242,335 1.0
Dynamite (75 per cent. nitro-glycerine) 548,250 2.26
Blasting gelatine (92 per cent. nitro-glycerine) 766,813 3.16
Nitro-glycerine 794,563 3.28
Experiments made in lead cylinders give—
Dynamite 1.0
Blasting gelatine 1.4
Nitro-glycerine 1.4
Sir Frederick Abel and Captain W.H. Noble, R.A., have shown that the
maximum pressure exerted by gunpowder is equal to 486 foot-tons per lb.
of powder, or that when 1 kilo, of the powder gases occupy the volume of 1
litre, the pressure is equal to 6,400 atmospheres; and Berthelot has
calculated that every gramme of nitro-glycerine exploded gives 1,320 units
of heat. MM. Roux and Sarrau, of the Depôt Centrales des Poudres, Paris,
by means of calorimetric determinations, have shown that the following
units of heat are produced by the detonation of—
Nitro-glycerine 1,784 heat units.
Gun-cotton 1,123 "
Potassic picrate 840 "
which, multiplied by the mechanical equivalent per unit, gives—
Nitro-glycerine 778 metre tons per kilogramme.
Gun-cotton 489 " "
Picrate of potash 366 " "
Page 287
~Nobel's Ballistic Test.~—Alfred Nobel was the first to make use of the
mortar test to measure the (ballistic) power of explosives. The use of the
mortar for measuring the relative power of explosives does not give very
accurate results, but at the same time the information obtained is of
considerable value from a practical point of view. The mortar consists of a
solid cylinder of cast iron, one end of which has been bored to a depth of 9
inches, the diameter of the bore being 4 inches. At the bottom of the bore-
hole is a steel disc 3 inches thick, in which another hole has been bored 3
inches by 2 inches. The mortar (Fig. 54) itself is fitted with trunnions, and
firmly fixed in a very solid wooden carriage, which is securely bolted down
to the ground. The shot used should weigh 28 lbs., and be turned accurately
to fit the bore of the mortar. Down its centre is a hole through which the
fuse is put.
The following is the method of making an experiment:—A piece of hard
wood is turned in the lathe to exactly fit the hole in the steel disc at the
bottom of the bore. This wooden cylinder itself contains a small cavity into
which the explosive is put. Ten grms. is a very convenient quantity. Before
placing in the mortar, a hole may be made in the explosive by means of a
piece of glass rod of such a size that the detonator to be used will just fit
into it. After placing the wooden cylinder containing the explosive in the
cavity at the bottom of the bore, the shot, slightly oiled, is allowed to fall
gently down on to it. A piece of fuse about a foot long, and fitted with a
detonator, is now pushed through the hole in the centre of the shot until the
detonator is embedded in the explosive. The fuse is now lighted, and the
distance to which the shot is thrown is carefully measured. The range
should be marked out with pegs into yards and fractions of yards, especially
at the end opposite to the mortar. The mortar should be inclined at an angle
of 45°. In experimenting with this apparatus, the force and direction of the
wind will be found to have considerable influence.
mortar test to measure the (ballistic) power of explosives. The use of the
mortar for measuring the relative power of explosives does not give very
accurate results, but at the same time the information obtained is of
considerable value from a practical point of view. The mortar consists of a
solid cylinder of cast iron, one end of which has been bored to a depth of 9
inches, the diameter of the bore being 4 inches. At the bottom of the bore-
hole is a steel disc 3 inches thick, in which another hole has been bored 3
inches by 2 inches. The mortar (Fig. 54) itself is fitted with trunnions, and
firmly fixed in a very solid wooden carriage, which is securely bolted down
to the ground. The shot used should weigh 28 lbs., and be turned accurately
to fit the bore of the mortar. Down its centre is a hole through which the
fuse is put.
The following is the method of making an experiment:—A piece of hard
wood is turned in the lathe to exactly fit the hole in the steel disc at the
bottom of the bore. This wooden cylinder itself contains a small cavity into
which the explosive is put. Ten grms. is a very convenient quantity. Before
placing in the mortar, a hole may be made in the explosive by means of a
piece of glass rod of such a size that the detonator to be used will just fit
into it. After placing the wooden cylinder containing the explosive in the
cavity at the bottom of the bore, the shot, slightly oiled, is allowed to fall
gently down on to it. A piece of fuse about a foot long, and fitted with a
detonator, is now pushed through the hole in the centre of the shot until the
detonator is embedded in the explosive. The fuse is now lighted, and the
distance to which the shot is thrown is carefully measured. The range
should be marked out with pegs into yards and fractions of yards, especially
at the end opposite to the mortar. The mortar should be inclined at an angle
of 45°. In experimenting with this apparatus, the force and direction of the
wind will be found to have considerable influence.
Page 288
[Illustration: FIG. 54.—MORTAR FOR MEASURING THE
BALLISTIC POWER OF
EXPLOSIVES. A, Shot; B, Steel Disc; C, Section of Mortar (Cast
Iron); D, Wooden Plug holding Explosive (E); F, Fuse.]
Mr T. Johnson made some ballistic tests. He used a steel mortar and a
shot weighing 29 Ibs., and he adopted the plan of measuring the distance to
which a given charge, 5 grms., would throw the shot. He obtained the
following results:—
Range in Feet.
Blasting gelatine (90 per cent. nitro-glycerine and nitro-cellulose) 392
Ammonite (60 per cent. Am(NO_{3}) and 10 per cent. nitro-naphthalene)
310
Gelignite (60 per cent. nitro-gelatine and gun-cotton) 306
Roburite (AmNO_{3} and chloro-nitro-benzol) 294
No. 1 dynamite (75 per cent. nitro-gelatine) 264
Stonite (68 per cent. nitro-gelatine and 32 per cent. wood-meal) 253
Gun-cotton 234
Tonite (gun-cotton and nitrates) 223
Carbonite (25 per cent. nitro-gelatine, 40 per cent. wood-meal,
and 30 per cent. nitrates) 198
Securite (KNO_{3} and nitro-benzol) 183
Gunpowder 143
~Calculation of the Volume of Gas Evolved in an Explosive Reaction.~
—The volume of gas evolved in an explosive reaction may be calculated,
but only when they are simple and stable products, such calculations being
made at 0° and 760 mm. Let it be required, for example, to determine the
volume of gas evolved by 1 gram-molecule of nitro-glycerine. The
explosive reaction of nitro-glycerine may be represented by the equation.
BALLISTIC POWER OF
EXPLOSIVES. A, Shot; B, Steel Disc; C, Section of Mortar (Cast
Iron); D, Wooden Plug holding Explosive (E); F, Fuse.]
Mr T. Johnson made some ballistic tests. He used a steel mortar and a
shot weighing 29 Ibs., and he adopted the plan of measuring the distance to
which a given charge, 5 grms., would throw the shot. He obtained the
following results:—
Range in Feet.
Blasting gelatine (90 per cent. nitro-glycerine and nitro-cellulose) 392
Ammonite (60 per cent. Am(NO_{3}) and 10 per cent. nitro-naphthalene)
310
Gelignite (60 per cent. nitro-gelatine and gun-cotton) 306
Roburite (AmNO_{3} and chloro-nitro-benzol) 294
No. 1 dynamite (75 per cent. nitro-gelatine) 264
Stonite (68 per cent. nitro-gelatine and 32 per cent. wood-meal) 253
Gun-cotton 234
Tonite (gun-cotton and nitrates) 223
Carbonite (25 per cent. nitro-gelatine, 40 per cent. wood-meal,
and 30 per cent. nitrates) 198
Securite (KNO_{3} and nitro-benzol) 183
Gunpowder 143
~Calculation of the Volume of Gas Evolved in an Explosive Reaction.~
—The volume of gas evolved in an explosive reaction may be calculated,
but only when they are simple and stable products, such calculations being
made at 0° and 760 mm. Let it be required, for example, to determine the
volume of gas evolved by 1 gram-molecule of nitro-glycerine. The
explosive reaction of nitro-glycerine may be represented by the equation.
Page 289
C_{3}H_{5}O_{3}(NO_{2}){3} = 3CO{2} + 2-1/2H_{2}O + 1-
1/2N_{2} + 1/4O_{2}
By weight 227 = 132 + 45 + 42 + 8
By volume 2 = 3 + 2-1/2 + 1-1/2 + 1/4
The weights of the several products of the above reactions are calculated
by multiplying their specific gravities by the weight of 1 litre of hydrogen at
0° C. and 760 mm. (0.0896 grm). Thus,
One litre of CO_{2} = 22 x .0896 = 1.9712 grm.
" H_{2}O = 9 x " = 0.8064 "
" N_{2} = 14 x " = 1.2544 "
" O_{2} = 16 x " = 1.4336 "
The volume of permanent gases at 0° and 760 mm. is constant, and
assuming the gramme as the unit of mass, is found to be 22.32 litres. Thus:
—
Volume of 44 of CO_{2}, at 0° and 760 mm. = 44/1.9712 = 22.32 litres. 18 " H_{2}O " " =
18/0.8044 = 22.32 " 28 " N_{2} " " = 28/1.2544 = 22.32 " 32 " O_{2} " " = 32/1.4366 = 22.32 "
Therefore
132 grms. of CO_{2} at 0° C and 760 mm. = 22.32 x 3 = 66.96 litres.
45 " H_{2}O " " = 22.32 x 2-1/2 = 55.80 "
42 " N_{2} " " = 22.32 x 1-1/2 = 33.48 "
8 " O_{2} " " = 22.32 x 1/4 = 5.58 "
____________
161.82 " Therefore 1 gram-molecule or 227 grms. of nitro-glycerine
when exploded, produces 161.82 litres of gas at 0° C and 760 mm.
1/2N_{2} + 1/4O_{2}
By weight 227 = 132 + 45 + 42 + 8
By volume 2 = 3 + 2-1/2 + 1-1/2 + 1/4
The weights of the several products of the above reactions are calculated
by multiplying their specific gravities by the weight of 1 litre of hydrogen at
0° C. and 760 mm. (0.0896 grm). Thus,
One litre of CO_{2} = 22 x .0896 = 1.9712 grm.
" H_{2}O = 9 x " = 0.8064 "
" N_{2} = 14 x " = 1.2544 "
" O_{2} = 16 x " = 1.4336 "
The volume of permanent gases at 0° and 760 mm. is constant, and
assuming the gramme as the unit of mass, is found to be 22.32 litres. Thus:
—
Volume of 44 of CO_{2}, at 0° and 760 mm. = 44/1.9712 = 22.32 litres. 18 " H_{2}O " " =
18/0.8044 = 22.32 " 28 " N_{2} " " = 28/1.2544 = 22.32 " 32 " O_{2} " " = 32/1.4366 = 22.32 "
Therefore
132 grms. of CO_{2} at 0° C and 760 mm. = 22.32 x 3 = 66.96 litres.
45 " H_{2}O " " = 22.32 x 2-1/2 = 55.80 "
42 " N_{2} " " = 22.32 x 1-1/2 = 33.48 "
8 " O_{2} " " = 22.32 x 1/4 = 5.58 "
____________
161.82 " Therefore 1 gram-molecule or 227 grms. of nitro-glycerine
when exploded, produces 161.82 litres of gas at 0° C and 760 mm.
Page 290
To determine the volume of gas at the temperature of explosion, we
simply apply the law of Charles.[A] Thus—
V : V' :: T : T' or V' = VT'/T
in which V represents the original volume.
V' " new volume.
T " original temperature on the absolute scale.
T' " new temperature of the same scale
In the present case T' = 6001°.
Therefore substituting, we have
V' = 161.82x6001/273 = 3557 litres
or at the temperature of explosion 1 gram-molecule of nitro-glycerine
produces 3,557 litres of permanent gas.
[Footnote A: According to the law of Charles, the volume of any gas
varies directly as its temperature on the absolute scale, provided the
pressure remains constant. Knowing the temperature on the centigrade
scale, the corresponding temperature on the absolute scale is obtained by
adding 273 to the degrees centigrade.]
~Pressure or Crusher Gauge.~—There are many forms of this instrument.
As long ago as 1792 Count Rumford used a pressure gauge. The so-called
crusher gauge was, however, first used by Captain Sir Andrew Noble in his
researches on powder. Other forms are the Rodman[A] punch Uchatius
Eprouvette, and the crusher gauge of the English Commission on
Explosives. They are all based either upon the size of an indent made upon
a copper disc by a steel punch fitted to a piston, acted upon by the gases of
the explosive, or upon the crushing or flattening of copper or lead cylinders.
simply apply the law of Charles.[A] Thus—
V : V' :: T : T' or V' = VT'/T
in which V represents the original volume.
V' " new volume.
T " original temperature on the absolute scale.
T' " new temperature of the same scale
In the present case T' = 6001°.
Therefore substituting, we have
V' = 161.82x6001/273 = 3557 litres
or at the temperature of explosion 1 gram-molecule of nitro-glycerine
produces 3,557 litres of permanent gas.
[Footnote A: According to the law of Charles, the volume of any gas
varies directly as its temperature on the absolute scale, provided the
pressure remains constant. Knowing the temperature on the centigrade
scale, the corresponding temperature on the absolute scale is obtained by
adding 273 to the degrees centigrade.]
~Pressure or Crusher Gauge.~—There are many forms of this instrument.
As long ago as 1792 Count Rumford used a pressure gauge. The so-called
crusher gauge was, however, first used by Captain Sir Andrew Noble in his
researches on powder. Other forms are the Rodman[A] punch Uchatius
Eprouvette, and the crusher gauge of the English Commission on
Explosives. They are all based either upon the size of an indent made upon
a copper disc by a steel punch fitted to a piston, acted upon by the gases of
the explosive, or upon the crushing or flattening of copper or lead cylinders.
Page 291
[Footnote A: Invented by General Rodman, United States Engineers.]
[Illustration: FIG. 55.—PRESSURE GAUGE.]
Berthelot uses a cylinder of copper, as also did the English Commission,
but in the simpler form of apparatus mostly used by manufacturers lead
cylinders are used. This form of apparatus (Fig. 55) consists of a base of
iron to which four uprights a are fixed, set round the circumference of a 4-
inch circle; the lead plug rests upon the steel base let into the solid iron
block. A ring c holds the uprights d together at the top. The piston b, which
rests upon the lead plug, is a cylinder of tempered steel 4 inches in diameter
and 5 inches in length; it is turned away at the sides to lighten it as much as
possible. It should move freely between the uprights d. In the top of this
cylinder is a cavity to hold the charge of explosive. The weight of this
piston is 12-1/4 lbs. The shot e is of tempered steel, and 4 inches in
diameter and 10 inches in length, and weighs 34-1/2 lbs. It is bored through
its axis to receive a capped fuse.
The instrument is used in the following manner:—A plug of lead 1 inch
long and 1 inch in diameter, and of a cylindrical form, is placed upon the
steel plate between the uprights a, the piston placed upon it, the carefully
weighed explosive placed in the cavity, and the shot lowered gently upon
the piston. A piece of fuse, with a detonator fixed at one end, is then pushed
through the hole in the shot until it reaches the explosive contained in the
cavity in the piston. The fuse is lighted. When the charge is exploded, the
shot is thrown out, and the lead cylinder is more or less compressed. The
lead plugs must be of a uniform density and homogeneous structure, and
should be cut from lead rods that have been drawn, and not cast separately
from small masses of metal.
[Illustration: FIG. 56.—b, STEEL PUNCH; c, LEAD CYLINDER FOR
USE WITH
[Illustration: FIG. 55.—PRESSURE GAUGE.]
Berthelot uses a cylinder of copper, as also did the English Commission,
but in the simpler form of apparatus mostly used by manufacturers lead
cylinders are used. This form of apparatus (Fig. 55) consists of a base of
iron to which four uprights a are fixed, set round the circumference of a 4-
inch circle; the lead plug rests upon the steel base let into the solid iron
block. A ring c holds the uprights d together at the top. The piston b, which
rests upon the lead plug, is a cylinder of tempered steel 4 inches in diameter
and 5 inches in length; it is turned away at the sides to lighten it as much as
possible. It should move freely between the uprights d. In the top of this
cylinder is a cavity to hold the charge of explosive. The weight of this
piston is 12-1/4 lbs. The shot e is of tempered steel, and 4 inches in
diameter and 10 inches in length, and weighs 34-1/2 lbs. It is bored through
its axis to receive a capped fuse.
The instrument is used in the following manner:—A plug of lead 1 inch
long and 1 inch in diameter, and of a cylindrical form, is placed upon the
steel plate between the uprights a, the piston placed upon it, the carefully
weighed explosive placed in the cavity, and the shot lowered gently upon
the piston. A piece of fuse, with a detonator fixed at one end, is then pushed
through the hole in the shot until it reaches the explosive contained in the
cavity in the piston. The fuse is lighted. When the charge is exploded, the
shot is thrown out, and the lead cylinder is more or less compressed. The
lead plugs must be of a uniform density and homogeneous structure, and
should be cut from lead rods that have been drawn, and not cast separately
from small masses of metal.
[Illustration: FIG. 56.—b, STEEL PUNCH; c, LEAD CYLINDER FOR
USE WITH
Page 292
PRESSURE GAUGE.]
The strength of the explosive is proportional to the work performed in
reducing the height of the lead (or copper) plug, and to get an expression for
the work done it is necessary to find the number of foot-pounds (or
kilogrammetres) required to produce the different amounts of compression.
This is done by submitting exactly similar cylinders of lead to a crushing
under weights acting without initial velocity, and measuring the reduced
heights of the cylinders; from these results a table is constructed
establishing empirical relations between the reduced heights and the
corresponding weights; the cylinders are measured both before and after
insertion in the pressure gauge by means of an instrument known as the
micrometer calipers (Fig. 57).[A]
[Footnote A: An instrument called a "Foot-pounds Machine" has been
invented by Lieut. Quinan, U.S. Army. It consists of three boards,
connected so as to form a slide 16 feet high, in which a weight (the shot of
the pressure gauge) can fall freely. One of the boards is graduated into feet
and half feet. The horizontal board at the bottom, upon which the others are
nailed, rests upon a heavy post set deep in the ground, upon which is placed
the piston of the gauge, which in this case serves as an anvil on which to
place the lead cylinders. The shot is raised by means of a pulley, fixed at the
top of the structure, to any desired height, and let go by releasing the clutch
that holds it. The difference between the original length and the reduced
length gives the compression caused by the blow of the shot in falling, and
gives the value in foot-pounds required to produce the different amounts of
compression. (Vide Jour. U.S. Naval Inst., 1892.)]
[Illustration: FIG. 57.—MICROMETER CALIPERS FOR
MEASURING DIAMETER OF
LEAD CYLINDERS.]
The strength of the explosive is proportional to the work performed in
reducing the height of the lead (or copper) plug, and to get an expression for
the work done it is necessary to find the number of foot-pounds (or
kilogrammetres) required to produce the different amounts of compression.
This is done by submitting exactly similar cylinders of lead to a crushing
under weights acting without initial velocity, and measuring the reduced
heights of the cylinders; from these results a table is constructed
establishing empirical relations between the reduced heights and the
corresponding weights; the cylinders are measured both before and after
insertion in the pressure gauge by means of an instrument known as the
micrometer calipers (Fig. 57).[A]
[Footnote A: An instrument called a "Foot-pounds Machine" has been
invented by Lieut. Quinan, U.S. Army. It consists of three boards,
connected so as to form a slide 16 feet high, in which a weight (the shot of
the pressure gauge) can fall freely. One of the boards is graduated into feet
and half feet. The horizontal board at the bottom, upon which the others are
nailed, rests upon a heavy post set deep in the ground, upon which is placed
the piston of the gauge, which in this case serves as an anvil on which to
place the lead cylinders. The shot is raised by means of a pulley, fixed at the
top of the structure, to any desired height, and let go by releasing the clutch
that holds it. The difference between the original length and the reduced
length gives the compression caused by the blow of the shot in falling, and
gives the value in foot-pounds required to produce the different amounts of
compression. (Vide Jour. U.S. Naval Inst., 1892.)]
[Illustration: FIG. 57.—MICROMETER CALIPERS FOR
MEASURING DIAMETER OF
LEAD CYLINDERS.]
Page 293
~The Use of Lead Cylinders.~—The method of using lead cylinders to
test the strength of an explosive is a very simple affair, and is conducted as
follows:—A solid cast lead cylinder, of any convenient size, is bored down
the centre for some inches, generally until the bore-hole reaches to about
the centre of the block. The volume of this hole is then accurately measured
by pouring water into it from a graduated measure, and its capacity in cubic
centimetres noted. The bore-hole is then emptied and dried, and a weighed
quantity (say 10 grms.) of the explosive pressed well down to the bottom of
the hole. A hole is then made in the explosive (if dynamite) with a piece of
clean and rounded glass rod, large enough to take the detonator. A piece of
fuse, fitted with a detonator, is then inserted into the explosive and lighted.
After the explosion a large pear- shaped cavity will be found to have been
formed, the volume of which is then measured in the same way as before.
The results thus obtained are only relative, but are of considerable value
for comparing dynamites among themselves (or gun-cottons). Experiments
in lead cylinders gave the relative values for nitro-glycerine 1.4, blasting
gelatine 1.4, and dynamite 1.0. (Fig. 58 shows sections of lead cylinders
before and after use.)
[Illustration: FIG. 58.—LEAD CYLINDERS BEFORE AND AFTER
USE.]
Standard regulations for the preparation of lead cylinders may be found
in the Chem. Zeit., 1903, 27 [74], 898. They were drawn up by the Fifth
International Congress of App. Chem., Berlin. The cylinder of lead should
be 200 mm. in height and 200 mm. in diameter. In its axis is a bore-hole,
125 mm. deep and 25 mm. in diameter. The lead used must be pure and
soft, and the cylinder used in a series of tests must be cast from the same
melt. The temperature of the cylinders should be 15° to 20° throughout. Ten
grms. of explosive should be used and wrapped in tin-foil. A detonator with
test the strength of an explosive is a very simple affair, and is conducted as
follows:—A solid cast lead cylinder, of any convenient size, is bored down
the centre for some inches, generally until the bore-hole reaches to about
the centre of the block. The volume of this hole is then accurately measured
by pouring water into it from a graduated measure, and its capacity in cubic
centimetres noted. The bore-hole is then emptied and dried, and a weighed
quantity (say 10 grms.) of the explosive pressed well down to the bottom of
the hole. A hole is then made in the explosive (if dynamite) with a piece of
clean and rounded glass rod, large enough to take the detonator. A piece of
fuse, fitted with a detonator, is then inserted into the explosive and lighted.
After the explosion a large pear- shaped cavity will be found to have been
formed, the volume of which is then measured in the same way as before.
The results thus obtained are only relative, but are of considerable value
for comparing dynamites among themselves (or gun-cottons). Experiments
in lead cylinders gave the relative values for nitro-glycerine 1.4, blasting
gelatine 1.4, and dynamite 1.0. (Fig. 58 shows sections of lead cylinders
before and after use.)
[Illustration: FIG. 58.—LEAD CYLINDERS BEFORE AND AFTER
USE.]
Standard regulations for the preparation of lead cylinders may be found
in the Chem. Zeit., 1903, 27 [74], 898. They were drawn up by the Fifth
International Congress of App. Chem., Berlin. The cylinder of lead should
be 200 mm. in height and 200 mm. in diameter. In its axis is a bore-hole,
125 mm. deep and 25 mm. in diameter. The lead used must be pure and
soft, and the cylinder used in a series of tests must be cast from the same
melt. The temperature of the cylinders should be 15° to 20° throughout. Ten
grms. of explosive should be used and wrapped in tin-foil. A detonator with
Page 294
a charge of 2 grms., to be fired electrically, is placed in the midst of the
explosive. The cartridge is placed in the bore-hole, and gently pressed
against the bottom, the firing wires being kept in central position. The bore-
hole is then filled with dry quartz sand, which must pass through a sieve of
144 meshes to the sq. cm., the wires being .35 mm. diameter. The sand is
filled in evenly, any excess being levelled off. The charge thus prepared is
then fired electrically. The lead cylinder is then inverted, and any residues
removed with a brush. The number of c.c. of water required to fill the
cavity, in excess of the original volume of the bore-hole, is a measure of the
strength of the explosive. The results are only comparable if made with the
same class of explosive. A result is to be the mean of at least three
experiments. The accuracy of the method depends on (a) the uniform
temperature of the lead cylinder (15° to 20° C. 7); (b) on the uniformity of
the quartz sand; (c) on the uniformity of the measurements.
[Illustration: FIG. 59.—NOBLE'S PRESSURE GAUGE.]
~Noble's Pressure Gauge.~—The original explosive vessels used by
Captain Sir A. Noble in his first experiments were practically exactly
similar to those that he now employs, which consists of a steel barrel A
(Fig. 59), open at both ends, which are closed by carefully fitted screw
plugs, furnished with steel gas checks to prevent any escape past the screw.
The action of the gas checks is exactly the same as the leathers used in
hydraulic presses. The pressure of the gas acting on both sides of the
annular space presses these sides firmly against the cylinder and against the
plug, and so effectually prevents any escape. In the firing plug F is a conical
hole closed by a cone fitting with great exactness, which, when the vessel is
prepared for firing, is covered with fine tissue paper to act as an insulator.
The two firing wires GG, one in the insulated cone, the other in the firing
plug, are connected by a very fine platinum wire passing through a glass
tube filled with meal powder. The wire becomes red-hot when connection is
explosive. The cartridge is placed in the bore-hole, and gently pressed
against the bottom, the firing wires being kept in central position. The bore-
hole is then filled with dry quartz sand, which must pass through a sieve of
144 meshes to the sq. cm., the wires being .35 mm. diameter. The sand is
filled in evenly, any excess being levelled off. The charge thus prepared is
then fired electrically. The lead cylinder is then inverted, and any residues
removed with a brush. The number of c.c. of water required to fill the
cavity, in excess of the original volume of the bore-hole, is a measure of the
strength of the explosive. The results are only comparable if made with the
same class of explosive. A result is to be the mean of at least three
experiments. The accuracy of the method depends on (a) the uniform
temperature of the lead cylinder (15° to 20° C. 7); (b) on the uniformity of
the quartz sand; (c) on the uniformity of the measurements.
[Illustration: FIG. 59.—NOBLE'S PRESSURE GAUGE.]
~Noble's Pressure Gauge.~—The original explosive vessels used by
Captain Sir A. Noble in his first experiments were practically exactly
similar to those that he now employs, which consists of a steel barrel A
(Fig. 59), open at both ends, which are closed by carefully fitted screw
plugs, furnished with steel gas checks to prevent any escape past the screw.
The action of the gas checks is exactly the same as the leathers used in
hydraulic presses. The pressure of the gas acting on both sides of the
annular space presses these sides firmly against the cylinder and against the
plug, and so effectually prevents any escape. In the firing plug F is a conical
hole closed by a cone fitting with great exactness, which, when the vessel is
prepared for firing, is covered with fine tissue paper to act as an insulator.
The two firing wires GG, one in the insulated cone, the other in the firing
plug, are connected by a very fine platinum wire passing through a glass
tube filled with meal powder. The wire becomes red-hot when connection is
Page 295
made with a Leclanché battery, and the charge which has previously been
inserted into the vessel is fired. The crusher plug is fitted with a crusher
gauge H for determining the pressure of the gases at the moment of
explosion, and in addition there is frequently a second crusher gauge
apparatus screwed into the cylinder. When it is desired to allow the gases to
escape for examination, the screw J is slightly withdrawn. The gases then
pass into the passage I, and can be led to suitable apparatus in which their
volume can be measured, or in which they can be sealed for subsequent
chemical analysis.
The greatest care must be exercised in carrying out experiments with this
apparatus; it is particularly necessary to be sure that all the joints are
perfectly tight before exploding the charge. Should this not be the case, the
gases upon their generation will cut their way out, or completely blow out
the part improperly secured, in either case destroying the apparatus. The
effect produced upon the apparatus when the gas has escaped by cutting a
passage for itself is very curious. The surface of the metal where the escape
occurred presents the appearance of having been washed away in a state of
fusion by the rush of the highly heated products.
~The Pressure Gauge.~—The pressure is found by the use of a little
instrument known as the pressure gauge which consists of a small chamber
formed of steel, inside of which is a copper cylinder, and the entrance being
closed by a screw gland, in which a piston, having a definite sectional area,
works. There is a gas check E (Fig. 60) placed in the gland, and over the
piston, which prevents the admission of gas to the chamber. When it is
desired to find the pressure in the chamber of a gun, one or more of these
crushers are made up with or inserted at the extreme rear end of the
cartridge, in order to avoid their being blown out of the gun when fired.
This, however, often takes place, in which case the gauges are usually found
a few yards in front of the muzzle. The copper cylinders which register the
inserted into the vessel is fired. The crusher plug is fitted with a crusher
gauge H for determining the pressure of the gases at the moment of
explosion, and in addition there is frequently a second crusher gauge
apparatus screwed into the cylinder. When it is desired to allow the gases to
escape for examination, the screw J is slightly withdrawn. The gases then
pass into the passage I, and can be led to suitable apparatus in which their
volume can be measured, or in which they can be sealed for subsequent
chemical analysis.
The greatest care must be exercised in carrying out experiments with this
apparatus; it is particularly necessary to be sure that all the joints are
perfectly tight before exploding the charge. Should this not be the case, the
gases upon their generation will cut their way out, or completely blow out
the part improperly secured, in either case destroying the apparatus. The
effect produced upon the apparatus when the gas has escaped by cutting a
passage for itself is very curious. The surface of the metal where the escape
occurred presents the appearance of having been washed away in a state of
fusion by the rush of the highly heated products.
~The Pressure Gauge.~—The pressure is found by the use of a little
instrument known as the pressure gauge which consists of a small chamber
formed of steel, inside of which is a copper cylinder, and the entrance being
closed by a screw gland, in which a piston, having a definite sectional area,
works. There is a gas check E (Fig. 60) placed in the gland, and over the
piston, which prevents the admission of gas to the chamber. When it is
desired to find the pressure in the chamber of a gun, one or more of these
crushers are made up with or inserted at the extreme rear end of the
cartridge, in order to avoid their being blown out of the gun when fired.
This, however, often takes place, in which case the gauges are usually found
a few yards in front of the muzzle. The copper cylinders which register the
Page 296
pressure are made 0.5 inch long from specially selected copper, the
diameters being regulated to give a sectional area of either 1/12 or 1/24
square inch.
[Illustration: FIG. 60.—CRUSHER GAUGE. E, GAS CHECK.]
Hollow copper cylinders are manufactured with reduced sectional areas
for measuring very small pressures. It has been found that these copper
cylinders are compressed to definite lengths for certain pressures with
remarkable uniformity. Thus a copper cylinder having a sectional area of
1/12 square inch, and originally 1/2 inch long, is crushed to a length of 0.42
inch by a pressure of 10 tons per square inch. By subsequently applying a
pressure of 12 tons per square inch the cylinder is reduced to a length of
0.393 inch. Before using the cylinders, whether for experimenting with
closed vessels or with guns, it is advisable to first crush them by a pressure
a little under that expected in the experiment. Captain Sir A. Noble used in
his experiments a modification of Rodman's gauge. (Ordnance Dept.,
U.S.A., 1861.)
~By Calculation.~—To calculate the pressure developed by the explosion
of dynamite in a bore-hole 3 centimetres in diameter, charged with 1
kilogramme of 75 per cent. dynamite, Messrs Vieille and Sarrau employ the
following formula:—
P = V_{o}(1 + Q/273.c)/(V - v).
Where V_{o} = the volume (reduced to 0° and 760 mm.) of the gases
produced by a unit of weight of the explosive; Q the number of calories
disengaged by a unit of weight of the explosive; c equals the specific heat at
constant volume of the gases; V the volume in cubic centimetres of a unit of
weight of the explosive; v the volume occupied by the inert materials of the
diameters being regulated to give a sectional area of either 1/12 or 1/24
square inch.
[Illustration: FIG. 60.—CRUSHER GAUGE. E, GAS CHECK.]
Hollow copper cylinders are manufactured with reduced sectional areas
for measuring very small pressures. It has been found that these copper
cylinders are compressed to definite lengths for certain pressures with
remarkable uniformity. Thus a copper cylinder having a sectional area of
1/12 square inch, and originally 1/2 inch long, is crushed to a length of 0.42
inch by a pressure of 10 tons per square inch. By subsequently applying a
pressure of 12 tons per square inch the cylinder is reduced to a length of
0.393 inch. Before using the cylinders, whether for experimenting with
closed vessels or with guns, it is advisable to first crush them by a pressure
a little under that expected in the experiment. Captain Sir A. Noble used in
his experiments a modification of Rodman's gauge. (Ordnance Dept.,
U.S.A., 1861.)
~By Calculation.~—To calculate the pressure developed by the explosion
of dynamite in a bore-hole 3 centimetres in diameter, charged with 1
kilogramme of 75 per cent. dynamite, Messrs Vieille and Sarrau employ the
following formula:—
P = V_{o}(1 + Q/273.c)/(V - v).
Where V_{o} = the volume (reduced to 0° and 760 mm.) of the gases
produced by a unit of weight of the explosive; Q the number of calories
disengaged by a unit of weight of the explosive; c equals the specific heat at
constant volume of the gases; V the volume in cubic centimetres of a unit of
weight of the explosive; v the volume occupied by the inert materials of the
Page 297
explosive. The volume of gas produced by the explosion of 1 kilogramme
of nitro-glycerine (at 0° and 760 mm.) is 467 litres.
V_{o} will therefore equal 0.75 x 467 = 350.25.
The specific heat c is, according to Sarrau, .220 (c); and according to
Bunsen, 1 kilogramme of dynamite No. 1 disengages 1,290 (Q) calories.
The density of dynamite is equal to 1.5, therefore
V = 1/1.5 = .666.
If we take the volume of the kieselguhr as .1, we find from above
formula that
P = 350(1 + 1290/(273 x .222))/(.600 - .1) = 13,900 atmospheres,
which is equal to 14,317 kilogrammes per square centimetre. The
pressure developed by 1 kilogramme of pure nitro-glycerine equals 18,533
atmospheres, equals 19,151 kilogrammes. Applying this formula to gun-
cotton, and taking after Berthelot, Q = 1075, and after Vieille and Sarrau,
V_{o} = 671 litres, and c as .2314, and the density of the nitro-cellulose as
1.5, we have (V = O)
P = 671(1 + 1075/(273 x .2314))/.666 = 18,135 atmospheres.
To convert this into pressure of kilogrammes per square centimetre, it is
necessary to multiply it by the weight of a column of mercury 0.760 m.
high, and 1 square centimetre in section, which is equal to increasing it by
1/30. It thus becomes
P^{k} = (1 + 1/30).
P^{k} = 18,135 x 1.033 = 18,733 kilogrammes.
of nitro-glycerine (at 0° and 760 mm.) is 467 litres.
V_{o} will therefore equal 0.75 x 467 = 350.25.
The specific heat c is, according to Sarrau, .220 (c); and according to
Bunsen, 1 kilogramme of dynamite No. 1 disengages 1,290 (Q) calories.
The density of dynamite is equal to 1.5, therefore
V = 1/1.5 = .666.
If we take the volume of the kieselguhr as .1, we find from above
formula that
P = 350(1 + 1290/(273 x .222))/(.600 - .1) = 13,900 atmospheres,
which is equal to 14,317 kilogrammes per square centimetre. The
pressure developed by 1 kilogramme of pure nitro-glycerine equals 18,533
atmospheres, equals 19,151 kilogrammes. Applying this formula to gun-
cotton, and taking after Berthelot, Q = 1075, and after Vieille and Sarrau,
V_{o} = 671 litres, and c as .2314, and the density of the nitro-cellulose as
1.5, we have (V = O)
P = 671(1 + 1075/(273 x .2314))/.666 = 18,135 atmospheres.
To convert this into pressure of kilogrammes per square centimetre, it is
necessary to multiply it by the weight of a column of mercury 0.760 m.
high, and 1 square centimetre in section, which is equal to increasing it by
1/30. It thus becomes
P^{k} = (1 + 1/30).
P^{k} = 18,135 x 1.033 = 18,733 kilogrammes.
Page 298
The following tables, taken from Messrs William Macnab's and E.
Ristori's paper (Proc. Roy. Soc., 56, 8-19), "Researches on Modern
Explosives," are very interesting. They record the results of a large number
of experiments made to determine the amount of heat evolved, and the
quantity and composition of the gases produced when certain explosives
and various smokeless powders were fired in a closed vessel from which
the air had been previously exhausted. The explosions were carried out in a
"calorimetric bomb" of Berthelot's pattern.[A]
[Footnote A: For description of "bomb," see "Explosives and their
Power,"
Berthelot, trans. by Hake and Macnab, p. 150. (Murray.)]
Table Showing Quantity of Heat and Volume and Analysis of Gas
Developed per Gramme with Different Sporting and Military Smokeless
Powders Now In Use
___________________________________________________________
___________
|||||
Name of Explosive. | Calories | Permanent | Aqueous | Total Volume |
| per grm. | Gases. | Vapour. | of Gas at 0° |
| | | | and 760 mm. |
______________________|__________|___________|_________|_______
_______|
| | cc/grm | cc/grm | cc/grm |
E.C. powder, English | 800 | 420 | 154 | 574 |
S.S. powder | 799 | 584 | 150 | 734 |
Troisdorf, German | 943 | 700 | 195 | 895 |
Rifleite, English | 864 | 766 | 159 | 925 |
B.N., French | 833 | 738 | 168 | 906 |
Ristori's paper (Proc. Roy. Soc., 56, 8-19), "Researches on Modern
Explosives," are very interesting. They record the results of a large number
of experiments made to determine the amount of heat evolved, and the
quantity and composition of the gases produced when certain explosives
and various smokeless powders were fired in a closed vessel from which
the air had been previously exhausted. The explosions were carried out in a
"calorimetric bomb" of Berthelot's pattern.[A]
[Footnote A: For description of "bomb," see "Explosives and their
Power,"
Berthelot, trans. by Hake and Macnab, p. 150. (Murray.)]
Table Showing Quantity of Heat and Volume and Analysis of Gas
Developed per Gramme with Different Sporting and Military Smokeless
Powders Now In Use
___________________________________________________________
___________
|||||
Name of Explosive. | Calories | Permanent | Aqueous | Total Volume |
| per grm. | Gases. | Vapour. | of Gas at 0° |
| | | | and 760 mm. |
______________________|__________|___________|_________|_______
_______|
| | cc/grm | cc/grm | cc/grm |
E.C. powder, English | 800 | 420 | 154 | 574 |
S.S. powder | 799 | 584 | 150 | 734 |
Troisdorf, German | 943 | 700 | 195 | 895 |
Rifleite, English | 864 | 766 | 159 | 925 |
B.N., French | 833 | 738 | 168 | 906 |
Page 299
Cordite, English | 1253 | 647 | 235 | 882 |
Ballistite, German | 1291 | 591 | 231 | 822 |
Ballistite, Italian | 1317 | 58l | 245 | 826 |
and Spanish | | | | |
______________________|__________|___________|_________|_______
_______|
The figures in column headed "Co-efficient of Potential Energy" serve as
a measure of comparison of the power of the explosives, and are the
products of the number of calories by the volume of gas, the last three
figures being suppressed in order to simplify the results.
The amounts of water found were calculated for comparison as volumes
of
H_{2}O gas at 0° and 760 mm.
E.C. powder consists principally of nitro-cellulose mixed with barium
nitrate and a small proportion of camphor.
S.S. of nitro-lignine mixed with barium nitrate and nitro-benzene.
Troisdorf powder is gelatinised nitro-cellulose; rifleite gelatinised nitro-
cellulose and nitro-benzene.
Cordite contains 58 per cent. nitro-glycerine, 37 per cent. gun-cotton, and
5 per cent. vaseline.
Ballistite (Italian) consists of equal parts nitro-cellulose and nitro-
glycerine, and 1/2 per cent. of aniline. The German contains a higher
percentage of nitro-cellulose.
TABLE SHOWING THE HEAT DEVELOPED BY EXPLOSIVES CONTAINING NITRO-
GLYCERINE AND NITRO-CELLULOSE IN DIFFERENT PROPORTIONS.
Ballistite, German | 1291 | 591 | 231 | 822 |
Ballistite, Italian | 1317 | 58l | 245 | 826 |
and Spanish | | | | |
______________________|__________|___________|_________|_______
_______|
The figures in column headed "Co-efficient of Potential Energy" serve as
a measure of comparison of the power of the explosives, and are the
products of the number of calories by the volume of gas, the last three
figures being suppressed in order to simplify the results.
The amounts of water found were calculated for comparison as volumes
of
H_{2}O gas at 0° and 760 mm.
E.C. powder consists principally of nitro-cellulose mixed with barium
nitrate and a small proportion of camphor.
S.S. of nitro-lignine mixed with barium nitrate and nitro-benzene.
Troisdorf powder is gelatinised nitro-cellulose; rifleite gelatinised nitro-
cellulose and nitro-benzene.
Cordite contains 58 per cent. nitro-glycerine, 37 per cent. gun-cotton, and
5 per cent. vaseline.
Ballistite (Italian) consists of equal parts nitro-cellulose and nitro-
glycerine, and 1/2 per cent. of aniline. The German contains a higher
percentage of nitro-cellulose.
TABLE SHOWING THE HEAT DEVELOPED BY EXPLOSIVES CONTAINING NITRO-
GLYCERINE AND NITRO-CELLULOSE IN DIFFERENT PROPORTIONS.
Page 300
___________________________________________________________
___________
Composition of Explosives. | Calories per cent.
_____________________________________________|_______________
_________
Nitro-cellulose | |
(N = 13.3 per cent.). | Nitro-glycerine. |
||
100 per cent. dry pulp | 0 | 1061
100 " gelatinised | 0 | 922
90 " | 10 per cent. | 1044
80 " | 20 " | 1159
70 " | 30 " | 1267
60 " | 40 " | 1347
50 " | 50 " | 1410
40 " | 60 " | 1467
0 " | 100 " | 1652
__________________________|__________________|________________
________
||
Nitro-cellulose | |
(N=12.24 per cent.) | Nitro-glycerine. |
||
80 per cent. | 20 per cent. | 1062
60 " | 40 " | 1288
50 " | 50 " | 1349
40 " | 60 " | 1405
||
__________________________|__________________|________________
________|
___________
Composition of Explosives. | Calories per cent.
_____________________________________________|_______________
_________
Nitro-cellulose | |
(N = 13.3 per cent.). | Nitro-glycerine. |
||
100 per cent. dry pulp | 0 | 1061
100 " gelatinised | 0 | 922
90 " | 10 per cent. | 1044
80 " | 20 " | 1159
70 " | 30 " | 1267
60 " | 40 " | 1347
50 " | 50 " | 1410
40 " | 60 " | 1467
0 " | 100 " | 1652
__________________________|__________________|________________
________
||
Nitro-cellulose | |
(N=12.24 per cent.) | Nitro-glycerine. |
||
80 per cent. | 20 per cent. | 1062
60 " | 40 " | 1288
50 " | 50 " | 1349
40 " | 60 " | 1405
||
__________________________|__________________|________________
________|
Page 301
Nitro-cellulose | |
(N = 13.3 per cent.). | Nitro-glycerine. | Vaseline.
||
55 per cent. | 40 per cent. | 5 per cent. 1134
35 " | 60 " | 5 " 1280
__________________________|__________________|________________
________
TABLE OF RESULTS OBTAINED BY LIEUT. W. WALKE., OF THE ARTILLERY, U.S.A,
WITH QUINAN'S PRESSURE GAUGE.
Nitro-glycerine being taken as 100. (From U.S. Naval Inst. Jour.)
___________________________________________________________
_______________
|||
| Compression | Order of |
Name of Explosive. | of Lead | Strength. |
|||
| Inch. | |
Explosive gelatine | 0.585 | 106.17 |
Hellhoffite | 0.585 | 106.17 |
Nitro-glycerine | 0.551 | 100.00 | Standard, N.G.
Nobel's smokeless powder | 0.509 | 92.38 |
Nitro-glycerine | 0.509 | 92.37 |
Gun-cotton | 0.458 | 83.12 | U.S. naval torpedo
| | | gun-cotton
Gun-cotton | 0.458 | 83.12 | Stowmarket.
Nitro-glycerine | 0.451 | 81.85 | Vouges, N.G.
Gun-cotton | 0.448 | 81.31 |
Dynamite No. 1 | 0.448 | 81.31 |
Dynamite de Traul | 0.437 | 79.31 |
(N = 13.3 per cent.). | Nitro-glycerine. | Vaseline.
||
55 per cent. | 40 per cent. | 5 per cent. 1134
35 " | 60 " | 5 " 1280
__________________________|__________________|________________
________
TABLE OF RESULTS OBTAINED BY LIEUT. W. WALKE., OF THE ARTILLERY, U.S.A,
WITH QUINAN'S PRESSURE GAUGE.
Nitro-glycerine being taken as 100. (From U.S. Naval Inst. Jour.)
___________________________________________________________
_______________
|||
| Compression | Order of |
Name of Explosive. | of Lead | Strength. |
|||
| Inch. | |
Explosive gelatine | 0.585 | 106.17 |
Hellhoffite | 0.585 | 106.17 |
Nitro-glycerine | 0.551 | 100.00 | Standard, N.G.
Nobel's smokeless powder | 0.509 | 92.38 |
Nitro-glycerine | 0.509 | 92.37 |
Gun-cotton | 0.458 | 83.12 | U.S. naval torpedo
| | | gun-cotton
Gun-cotton | 0.458 | 83.12 | Stowmarket.
Nitro-glycerine | 0.451 | 81.85 | Vouges, N.G.
Gun-cotton | 0.448 | 81.31 |
Dynamite No. 1 | 0.448 | 81.31 |
Dynamite de Traul | 0.437 | 79.31 |
Page 302
Emmensite | 0.429 | 77.86 |
Amide powder | 0.385 | 69.87 |
Oxonite | 0.383 | 69.51 |
Tonite | 0.376 | 68.24 | G.C. 52.5%, and
| | | Ba(NO_{3})_{2}, 47.5%
Bellite | 0.362 | 65.70 |
Rack-a-rock | 0.340 | 61.71 |
Atlas powder | 0.333 | 60.43 |
Ammonia dynamite | 0.332 | 60.25 |
Volney's powder No. 1 | 0.322 | 58.44 | Nitrated naphthalene.
" No. 2 | 0.294 | 53.18 | " "
Melinite | 0.280 | 50.82 | Picric acid 70%, and
| | | sol. nitro-cotton 30%.
Silver fulminate | 0.277 | 50.27 |
Mercury | 0.275 | 49.91 |
Mortar powder | 0.155 | 28.13 |
_________________________|_____________|___________|__________
____________
~Composition of some of the Explosives in Common Use.~
~Ordinary Dynamite.~
Nitro-Glycerine 75 per cent.
Kieselguhr 25 "
~Amvis.~
Nitrate of Ammonia 90 per cent.
Chloro-di-nitro Benzene 5 "
Wood Pulp 5 "
Amide powder | 0.385 | 69.87 |
Oxonite | 0.383 | 69.51 |
Tonite | 0.376 | 68.24 | G.C. 52.5%, and
| | | Ba(NO_{3})_{2}, 47.5%
Bellite | 0.362 | 65.70 |
Rack-a-rock | 0.340 | 61.71 |
Atlas powder | 0.333 | 60.43 |
Ammonia dynamite | 0.332 | 60.25 |
Volney's powder No. 1 | 0.322 | 58.44 | Nitrated naphthalene.
" No. 2 | 0.294 | 53.18 | " "
Melinite | 0.280 | 50.82 | Picric acid 70%, and
| | | sol. nitro-cotton 30%.
Silver fulminate | 0.277 | 50.27 |
Mercury | 0.275 | 49.91 |
Mortar powder | 0.155 | 28.13 |
_________________________|_____________|___________|__________
____________
~Composition of some of the Explosives in Common Use.~
~Ordinary Dynamite.~
Nitro-Glycerine 75 per cent.
Kieselguhr 25 "
~Amvis.~
Nitrate of Ammonia 90 per cent.
Chloro-di-nitro Benzene 5 "
Wood Pulp 5 "
Page 303
~Ammonia Nitrate Powder.~
Nitrate of Ammonia 80 per cent.
Chlorate of Potash 5 "
Nitro-Glucose 10 "
Coal Tar 5 "
~Celtite.~
Nitro-Glycerine 56-59 parts.
Nitro-Cotton 2-3.5 "
KNO_{3} 17-21 "
Wood Meal 8-9 "
Ammonium Oxalate 11-13 "
Moisture 0.5-1.5 "
~Atlas Powders.~
Sodium Nitrate 2.0 per cent.
Nitro-Glycerine 75.0 "
Wood Pulp 21.0 "
Magnesium Carbonate 2.0 "
~Dauline.~
Nitro-Glycerine 50 per cent.
Sawdust 30 "
Nitrate of Potash 20 "
~Vulcan Powder.~
Nitro-Glycerine 30 per cent.
Nitrate of Soda 52.5 "
Nitrate of Ammonia 80 per cent.
Chlorate of Potash 5 "
Nitro-Glucose 10 "
Coal Tar 5 "
~Celtite.~
Nitro-Glycerine 56-59 parts.
Nitro-Cotton 2-3.5 "
KNO_{3} 17-21 "
Wood Meal 8-9 "
Ammonium Oxalate 11-13 "
Moisture 0.5-1.5 "
~Atlas Powders.~
Sodium Nitrate 2.0 per cent.
Nitro-Glycerine 75.0 "
Wood Pulp 21.0 "
Magnesium Carbonate 2.0 "
~Dauline.~
Nitro-Glycerine 50 per cent.
Sawdust 30 "
Nitrate of Potash 20 "
~Vulcan Powder.~
Nitro-Glycerine 30 per cent.
Nitrate of Soda 52.5 "
Page 304
Sulphur 7.0 "
Charcoal 10.5 "
~Vigorite.~
Nitro-Glycerine 30 per cent.
Nitrate of Soda 60 "
Charcoal 5 "
Sawdust 5 "
~Rendrock.~
Nitrate of Potash 40 per cent.
Nitro-Glycerine 40 "
Wood Pulp 13 "
Paraffin or Pitch 7 "
~Ammonia Nitrate Powder.~
Ammonia Nitrate 80 per cent.
Potassium Chlorate 5 "
Nitro-Glucose 10 "
Coal Tar 5 "
~Hercules Powders.~
Nitro-Glycerine 75 to 40 per cent.
Sugar 1 " 15.66 "
Chlorate of Potash 1.05 " 3.34 "
Nitrate of Potash 2.10 " 31.00 "
Carbonate of Magnesia 20.85 " 10.00 "
~Carbo-Dynamite.~
Charcoal 10.5 "
~Vigorite.~
Nitro-Glycerine 30 per cent.
Nitrate of Soda 60 "
Charcoal 5 "
Sawdust 5 "
~Rendrock.~
Nitrate of Potash 40 per cent.
Nitro-Glycerine 40 "
Wood Pulp 13 "
Paraffin or Pitch 7 "
~Ammonia Nitrate Powder.~
Ammonia Nitrate 80 per cent.
Potassium Chlorate 5 "
Nitro-Glucose 10 "
Coal Tar 5 "
~Hercules Powders.~
Nitro-Glycerine 75 to 40 per cent.
Sugar 1 " 15.66 "
Chlorate of Potash 1.05 " 3.34 "
Nitrate of Potash 2.10 " 31.00 "
Carbonate of Magnesia 20.85 " 10.00 "
~Carbo-Dynamite.~
Page 305
Nitro-Glycerine 90 per cent.
Charcoal 10 "
~Geloxite (Permitted List).~
Nitro-Glycerine 64-54 parts.
Nitro-Cotton 5-4 "
Nitrate of Potash 22-13 "
Ammonium Oxalate 15-12 "
Red Ochre 1-0 "
Wood Meal 7-4 "
The Wood Meal to contain not more than 15% and not less than 5%
moisture.
~Giant Powder.~
Nitro-Glycerine 40 per cent.
Sodium Nitrate 40 "
Rosin 6 "
Sulphur 6 "
Guhr 8 "
~Dynamite de Trauzel.~
Nitro-Glycerine 75 parts.
Gun-Cotton 25 "
Charcoal 2 "
~Rhenish Dynamite.~
Solution of N.G. in Naphthalene 75 per cent.
Chalk, or Barium Sulphate 2 "
Charcoal 10 "
~Geloxite (Permitted List).~
Nitro-Glycerine 64-54 parts.
Nitro-Cotton 5-4 "
Nitrate of Potash 22-13 "
Ammonium Oxalate 15-12 "
Red Ochre 1-0 "
Wood Meal 7-4 "
The Wood Meal to contain not more than 15% and not less than 5%
moisture.
~Giant Powder.~
Nitro-Glycerine 40 per cent.
Sodium Nitrate 40 "
Rosin 6 "
Sulphur 6 "
Guhr 8 "
~Dynamite de Trauzel.~
Nitro-Glycerine 75 parts.
Gun-Cotton 25 "
Charcoal 2 "
~Rhenish Dynamite.~
Solution of N.G. in Naphthalene 75 per cent.
Chalk, or Barium Sulphate 2 "
Page 306
Kieselguhr 23 "
~Ammonia Dynamite.~
Ammonia Nitrate 75 parts.
Paraffin 4 "
Charcoal 3 "
Nitro-Glycerine 18 "
~Blasting Gelatine.~
Nitro-Glycerine 93 per cent.
Nitro-Cotton 3 to 7 "
~Gelatine Dynamite.~
Nitro-Glycerine 71 per cent.
Nitro-Cotton 6 "
Wood Pulp 5 "
Potassium Nitrate 18 "
~Gelignite.~
Nitro-Glycerine 60 to 61 per cent.
Nitro-Cotton 4 " 5 "
Wood Pulp 9 " 7 "
Potassium Nitrate 27 "
~Forcite.~
Nitro-Glycerine 49 per cent.
Nitro-Cotton 1.0 "
Sulphur 1.5 "
~Ammonia Dynamite.~
Ammonia Nitrate 75 parts.
Paraffin 4 "
Charcoal 3 "
Nitro-Glycerine 18 "
~Blasting Gelatine.~
Nitro-Glycerine 93 per cent.
Nitro-Cotton 3 to 7 "
~Gelatine Dynamite.~
Nitro-Glycerine 71 per cent.
Nitro-Cotton 6 "
Wood Pulp 5 "
Potassium Nitrate 18 "
~Gelignite.~
Nitro-Glycerine 60 to 61 per cent.
Nitro-Cotton 4 " 5 "
Wood Pulp 9 " 7 "
Potassium Nitrate 27 "
~Forcite.~
Nitro-Glycerine 49 per cent.
Nitro-Cotton 1.0 "
Sulphur 1.5 "
Page 307
Tar 10.0 "
Sodium Nitrate 38.0 "
Wood Pulp 5 "
(The N.-G., &c., varies.)
~Tonite No. 1.~
Gun-Cotton 52-50 per cent.
Barium Nitrate 47-40 "
~Tonite No. 2.~
Contains Charcoal also.
~Tonite No. 3.~
Gun-Cotton 18 to 20 per cent.
Ba(NO_3)_2 70 " 67 "
Di-nitro-Benzol 11 " 13 "
Moisture 0.5 " 1 "
~Carbonite.~
Nitro-Glycerine 17.76 per cent.
Nitro-Benzene 1.70 "
Soda 0.42 "
KNO_3 34.22 "
Ba(NO_3)_2 9.71 "
Cellulose 1.55 "
Cane Sugar 34.27 "
Moisture 0.36 "
________
Sodium Nitrate 38.0 "
Wood Pulp 5 "
(The N.-G., &c., varies.)
~Tonite No. 1.~
Gun-Cotton 52-50 per cent.
Barium Nitrate 47-40 "
~Tonite No. 2.~
Contains Charcoal also.
~Tonite No. 3.~
Gun-Cotton 18 to 20 per cent.
Ba(NO_3)_2 70 " 67 "
Di-nitro-Benzol 11 " 13 "
Moisture 0.5 " 1 "
~Carbonite.~
Nitro-Glycerine 17.76 per cent.
Nitro-Benzene 1.70 "
Soda 0.42 "
KNO_3 34.22 "
Ba(NO_3)_2 9.71 "
Cellulose 1.55 "
Cane Sugar 34.27 "
Moisture 0.36 "
________
Page 308
99.99
~Roburite.~
Ammonium Nitrate 86 per cent.
Chloro-di-nitro-Benzol 14 "
~Faversham Powder.~
Ammonium Nitrate 85 per cent.
Di-nitro-Benzol 10 "
Trench's Flame-extinguishing Compound 5 "
~Favierite No. 1.~
Ammonium Nitrate 88 per cent.
Di-nitro-Naphthalene 12 "
~Favierite No. 2.~
No. 1 Powder 90 per cent.
Ammon. Chloride 10 "
~Bellite.~
Ammonium Nitrate 5 parts.
Meta-di-nitro-Benzol 1 "
~Petrofacteur.~
Nitro-Benzene 10 per cent.
Chlorate of Potash 67 "
Nitrate of Potash 20 "
Sulphide of Antimony 3 "
~Roburite.~
Ammonium Nitrate 86 per cent.
Chloro-di-nitro-Benzol 14 "
~Faversham Powder.~
Ammonium Nitrate 85 per cent.
Di-nitro-Benzol 10 "
Trench's Flame-extinguishing Compound 5 "
~Favierite No. 1.~
Ammonium Nitrate 88 per cent.
Di-nitro-Naphthalene 12 "
~Favierite No. 2.~
No. 1 Powder 90 per cent.
Ammon. Chloride 10 "
~Bellite.~
Ammonium Nitrate 5 parts.
Meta-di-nitro-Benzol 1 "
~Petrofacteur.~
Nitro-Benzene 10 per cent.
Chlorate of Potash 67 "
Nitrate of Potash 20 "
Sulphide of Antimony 3 "
Page 309
~Securite.~
Mixtures of Meta-di-nitro-Benzol 26 per cent. and Nitrate of Ammonia
74 "
~Rack-a-Rock.~
Potassium Chlorate 79 parts.
Mono-nitro-Benzene 21 "
~Oxonite.~
Nitric Acid (sp. gr. 1.5) 54 parts.
Picric Acid 46 "
~Emmensite.~
Emmens Acid 5 parts.
Ammonium Nitrate 5 "
Picric Acid 6 "
~Brugère Powder.~
Ammonium Picrate 54 per cent.
Nitrate of Potash 46 "
~Designolle's Torpedo Powders.~
Potassium Picrate 55 to 50 per cent.
Nitrate of Potash 45 " 50 "
~Stowite.~
Mixtures of Meta-di-nitro-Benzol 26 per cent. and Nitrate of Ammonia
74 "
~Rack-a-Rock.~
Potassium Chlorate 79 parts.
Mono-nitro-Benzene 21 "
~Oxonite.~
Nitric Acid (sp. gr. 1.5) 54 parts.
Picric Acid 46 "
~Emmensite.~
Emmens Acid 5 parts.
Ammonium Nitrate 5 "
Picric Acid 6 "
~Brugère Powder.~
Ammonium Picrate 54 per cent.
Nitrate of Potash 46 "
~Designolle's Torpedo Powders.~
Potassium Picrate 55 to 50 per cent.
Nitrate of Potash 45 " 50 "
~Stowite.~
Page 310
Nitro-Glycerine 58 to 61 parts.
Nitro-Cotton 4.5 " 5 "
Potassium Nitrate 18 " 20 "
Wood Meal 6 " 7 "
Oxalate of Ammonia 11 " 15 "
The Wood Meal shall contain not more than 15% and not less than 5% by
weight of moisture. The explosive shall be used only when contained in a
non-water-proofed wrapper of parchment—No. 6 detonator.
~Faversham Powder.~
Nitrate of Ammonium 93 to 87
Tri-nitro-Toluol 11 " 9
Moisture 1 " —
~Kynite.~
Nitro-Glycerine 24-26 parts.
Wood-Pulp 2.5-3.5 "
Starch 32.5-3.5 "
Barium Nitrate 31.5-34.5 "
CaCO_{3} 0-0.5 "
Moisture 3.0-6.0 "
Must be put up only in water-proof parchment paper, and No. 6 electric
detonator used.
~Rexite.~
Nitro-Glycerine 6.5-8.5 parts.
Ammonium Nitrate 64-68 "
Sodium Nitrate 13-16 "
Nitro-Cotton 4.5 " 5 "
Potassium Nitrate 18 " 20 "
Wood Meal 6 " 7 "
Oxalate of Ammonia 11 " 15 "
The Wood Meal shall contain not more than 15% and not less than 5% by
weight of moisture. The explosive shall be used only when contained in a
non-water-proofed wrapper of parchment—No. 6 detonator.
~Faversham Powder.~
Nitrate of Ammonium 93 to 87
Tri-nitro-Toluol 11 " 9
Moisture 1 " —
~Kynite.~
Nitro-Glycerine 24-26 parts.
Wood-Pulp 2.5-3.5 "
Starch 32.5-3.5 "
Barium Nitrate 31.5-34.5 "
CaCO_{3} 0-0.5 "
Moisture 3.0-6.0 "
Must be put up only in water-proof parchment paper, and No. 6 electric
detonator used.
~Rexite.~
Nitro-Glycerine 6.5-8.5 parts.
Ammonium Nitrate 64-68 "
Sodium Nitrate 13-16 "
Page 311
Tri-nitro-Tolulene 6.5-8.5 "
Wood Meal 3-5 "
Moisture .5-1.4 "
Must be contained in water-proof case (stout paper), water-proofed with
Resin and Cerasin—No. 6 detonator.
~Withnell Powder.~
Ammonium Nitrate 88-92 parts.
Tri-nitro-Toluene 4-6 "
Flour (dried at 100° C.) 4-6 "
Moisture 0-15 "
Only to be used when contained in a linen paper cartridge, water-proofed
with Carnuba Wax, Parrafin—No. 7 detonator used.
~Phenix Powder.~
Nitro-Glycerine 28-31 parts.
Nitro-Cotton 0-1 "
Potassium Nitrate 30-34 "
Wood Meal 33-37 "
Moisture 2-6 "
~SMOKELESS POWDERS.~
~Cordite.~
Nitro-Glycerine 58 per cent. +or- .75
Nitro-Cotton 37 " +or- .65
Vaseline 5 " +or- .25
Wood Meal 3-5 "
Moisture .5-1.4 "
Must be contained in water-proof case (stout paper), water-proofed with
Resin and Cerasin—No. 6 detonator.
~Withnell Powder.~
Ammonium Nitrate 88-92 parts.
Tri-nitro-Toluene 4-6 "
Flour (dried at 100° C.) 4-6 "
Moisture 0-15 "
Only to be used when contained in a linen paper cartridge, water-proofed
with Carnuba Wax, Parrafin—No. 7 detonator used.
~Phenix Powder.~
Nitro-Glycerine 28-31 parts.
Nitro-Cotton 0-1 "
Potassium Nitrate 30-34 "
Wood Meal 33-37 "
Moisture 2-6 "
~SMOKELESS POWDERS.~
~Cordite.~
Nitro-Glycerine 58 per cent. +or- .75
Nitro-Cotton 37 " +or- .65
Vaseline 5 " +or- .25
Page 312
~Cordite, M.D.~
Nitro-Glycerine 30 per cent. +or- 1
Nitro-Cotton 65 " +or- 1
Vaseline 5 " +or- .25
Analysis of—
By W. Mancab and A.E. Leighton.
~E.C. Powder.~
Nitro-Cotton 79.0 per cent.
Potassium Nitrate 4.5 "
Barium Nitrate 7.5 "
Camphor 4.1 "
Wood Meal 3.8 "
Volatile Matter 1.1 "
~Walarode Powder.~
Nitro-Cotton 98.6 per cent.
Volatile Matter 1.4 "
~Kynoch's Smokeless.~
Nitro-Cotton 52.1 per cent.
Di-nitro-Toluene 19.5 "
Potassium Nitrate 1.4 "
Barium Nitrate 22.2 "
Wood Meal 2.7 "
Ash 0.9 "
Volatile Matter 1.2 "
Nitro-Glycerine 30 per cent. +or- 1
Nitro-Cotton 65 " +or- 1
Vaseline 5 " +or- .25
Analysis of—
By W. Mancab and A.E. Leighton.
~E.C. Powder.~
Nitro-Cotton 79.0 per cent.
Potassium Nitrate 4.5 "
Barium Nitrate 7.5 "
Camphor 4.1 "
Wood Meal 3.8 "
Volatile Matter 1.1 "
~Walarode Powder.~
Nitro-Cotton 98.6 per cent.
Volatile Matter 1.4 "
~Kynoch's Smokeless.~
Nitro-Cotton 52.1 per cent.
Di-nitro-Toluene 19.5 "
Potassium Nitrate 1.4 "
Barium Nitrate 22.2 "
Wood Meal 2.7 "
Ash 0.9 "
Volatile Matter 1.2 "
Page 313
~Schultze.~
Nitro-Lingin 62.1 per cent.
Potassium Nitrate 1.8 "
Barium Nitrate 26.1 "
Vaseline 4.9 "
Starch 3.5 "
Volatile Matter 1.0 "
~Imperial Schultze.~
Nitro-Lignin 80.1 per cent.
Barium Nitrate 10.2 "
Vaseline 7.9 "
Volatile Matter 1.8 "
~Cannonite.~
Nitro-Cotton 86.4 per cent.
Barium Nitrate 5.7 "
Vaseline 2.9 "
Lamp Black 1.3 "
Potassium Ferro-cyanide 2.4 "
Volatile Matter 1.3 "
~Amberite.~
Nitro-Cotton 71.0 per cent.
Potassium Nitrate 1.3 "
Barium Nitrate 18.6 "
Wood Meal 1.4 "
Vaseline 5.8 "
Nitro-Lingin 62.1 per cent.
Potassium Nitrate 1.8 "
Barium Nitrate 26.1 "
Vaseline 4.9 "
Starch 3.5 "
Volatile Matter 1.0 "
~Imperial Schultze.~
Nitro-Lignin 80.1 per cent.
Barium Nitrate 10.2 "
Vaseline 7.9 "
Volatile Matter 1.8 "
~Cannonite.~
Nitro-Cotton 86.4 per cent.
Barium Nitrate 5.7 "
Vaseline 2.9 "
Lamp Black 1.3 "
Potassium Ferro-cyanide 2.4 "
Volatile Matter 1.3 "
~Amberite.~
Nitro-Cotton 71.0 per cent.
Potassium Nitrate 1.3 "
Barium Nitrate 18.6 "
Wood Meal 1.4 "
Vaseline 5.8 "
Page 314
~Sporting Ballistite.~
Nitro-Glycerine 37.6 per cent
Nitro-Cotton 62.3 "
Volatile Matter 0.1 "
The following is a complete List of the Permitted Explosives as Defined
in the Schedules to the Explosives in Coal Mines Orders of the 20th
December 1902, of the 24th December 1903, of the 5th September 1903,
and 10th December 1903:—
Albionite.
Ammonal.
Ammonite.
Amvis.
Aphosite.
Arkite.
Bellite No. 1.
Bellite No. 2.
Bobbinite.
Britonite.
Cambrite.
Carbonite.
Clydite.
Coronite.
Dahmenite A.
Dragonite.
Electronite.
Faversham Powder.
Fracturite.
Geloxite.
Nitro-Glycerine 37.6 per cent
Nitro-Cotton 62.3 "
Volatile Matter 0.1 "
The following is a complete List of the Permitted Explosives as Defined
in the Schedules to the Explosives in Coal Mines Orders of the 20th
December 1902, of the 24th December 1903, of the 5th September 1903,
and 10th December 1903:—
Albionite.
Ammonal.
Ammonite.
Amvis.
Aphosite.
Arkite.
Bellite No. 1.
Bellite No. 2.
Bobbinite.
Britonite.
Cambrite.
Carbonite.
Clydite.
Coronite.
Dahmenite A.
Dragonite.
Electronite.
Faversham Powder.
Fracturite.
Geloxite.
Page 315
Haylite No. 1.
Kynite.
Negro Powder.
Nobel's Ardeer Powder.
Nobel Carbonite.
Normanite.
Pit-ite.
Roburite No. 3.
Saxonite.
Stow-ite.
Thunderite.
Victorite.
Virite.
West Falite No. 1.
West Falite No. 2.
Kynite.
Negro Powder.
Nobel's Ardeer Powder.
Nobel Carbonite.
Normanite.
Pit-ite.
Roburite No. 3.
Saxonite.
Stow-ite.
Thunderite.
Victorite.
Virite.
West Falite No. 1.
West Falite No. 2.
Page 316
INDEX.
Abel's, Sir Frederick, method of manufacturing gun-cotton, 57.
Abel's heat test, 249.
Acid mixture for nitrating nitro-glycerine, 23.
Air pressure in nitrator, 28.
Alkalinity in nitro-cellulose, 217.
Amberite, 189.
Ammonite, 149.
Analyses of collodion-cotton, 81. gelatine dynamites, 123.
Analysis of explosives, 197. acetone, 209. blasting gelatine, 199. cap
composition, 241. cordite, 206. celluloid, 230. dynamite, 197. forcite, 202.
fulminate, 240. glycerine, 233. gun-cotton, 212. nitric acid, 24. picric acid,
230. tonite, 205. waste acids, 239.
Armstrong on the constitution of the fulminates, 159.
Atlas powder, 119.
Abel's, Sir Frederick, method of manufacturing gun-cotton, 57.
Abel's heat test, 249.
Acid mixture for nitrating nitro-glycerine, 23.
Air pressure in nitrator, 28.
Alkalinity in nitro-cellulose, 217.
Amberite, 189.
Ammonite, 149.
Analyses of collodion-cotton, 81. gelatine dynamites, 123.
Analysis of explosives, 197. acetone, 209. blasting gelatine, 199. cap
composition, 241. cordite, 206. celluloid, 230. dynamite, 197. forcite, 202.
fulminate, 240. glycerine, 233. gun-cotton, 212. nitric acid, 24. picric acid,
230. tonite, 205. waste acids, 239.
Armstrong on the constitution of the fulminates, 159.
Atlas powder, 119.
Page 317
Auld on acetone, 211.
Axite, 176.
Ballistite, 179.
Beater or Hollander for pulping gun-cotton, 64.
Bedson, Prof., on roburite explosion gases, 140.
Bellite, 142.
Benzene, explosives derived from, 132.
Benzene, mono-nitro- and di-nitro-benzene, 134.
Bergmann and Junk on nitro-cellulose tests, 268.
Bernthsen summary of nitro-benzenes, 133.
Blasting gelatine, 119.
Blasting charge, preparation of, 166.
B.N. powder, 190.
Boiling-point of N.G., 19.
Boutnny's nitro-glycerine process, 15.
Brown on wet gun-cotton, 56.
Brugère's powder, 195.
Axite, 176.
Ballistite, 179.
Beater or Hollander for pulping gun-cotton, 64.
Bedson, Prof., on roburite explosion gases, 140.
Bellite, 142.
Benzene, explosives derived from, 132.
Benzene, mono-nitro- and di-nitro-benzene, 134.
Bergmann and Junk on nitro-cellulose tests, 268.
Bernthsen summary of nitro-benzenes, 133.
Blasting gelatine, 119.
Blasting charge, preparation of, 166.
B.N. powder, 190.
Boiling-point of N.G., 19.
Boutnny's nitro-glycerine process, 15.
Brown on wet gun-cotton, 56.
Brugère's powder, 195.
Page 318
Bucknill's resistance coil, 13.
Calculation of volume of gas evolved in an explosive reaction, 276.
Cannonite, 189.
Cellulose, 2, 47.
Celluloid manufacture, 91. analysis, 230. cartridges, 91. uses of, 90.
Field's papers on, 93. fibre for, 94. nitration of fibre, &c., 95. formula of,
57.
Champion and Pellet's method of determining nitrogen, 223.
Chenel's modification of Kjeldahl's method, 227.
Collodion-cotton, 79.
Comparative tests of black and nitro-powders, 193.
Compressing gun-cotton, 77.
Composition of waste acids from nitro-glycerine, 43.
Composition of some common explosives, 290.
Conduits for nitro-glycerine, 7.
Cooppal powder, 5, 189.
Cordite manufacture, 169. analysis, 206.
Cresilite, 158.
Calculation of volume of gas evolved in an explosive reaction, 276.
Cannonite, 189.
Cellulose, 2, 47.
Celluloid manufacture, 91. analysis, 230. cartridges, 91. uses of, 90.
Field's papers on, 93. fibre for, 94. nitration of fibre, &c., 95. formula of,
57.
Champion and Pellet's method of determining nitrogen, 223.
Chenel's modification of Kjeldahl's method, 227.
Collodion-cotton, 79.
Comparative tests of black and nitro-powders, 193.
Compressing gun-cotton, 77.
Composition of waste acids from nitro-glycerine, 43.
Composition of some common explosives, 290.
Conduits for nitro-glycerine, 7.
Cooppal powder, 5, 189.
Cordite manufacture, 169. analysis, 206.
Cresilite, 158.
Page 319
Cross and Bevan on nitro-jute, 107.
Crusher gauge, 284.
Cundill, Colonel, classification of dynamites, 112.
Danger area, 5.
Dangers in the manufacture of gun-cotton, 85.
Decomposition of cellulose, 54.
Definition of explosives in Order of Council (Explosives Act), 1.
Determination of N_{2}O_{4} in nitric acid, 24.
Determination of strength of H_{2}SO_{4}, 25.
Determination of relative strength of explosives, 272.
Detonators, 163.
Di-nitro-toluene, 138.
Dipping cotton in manufacture of gun-cotton, 60.
Divers and Kawakita on the fulminates, 159.
Dixon, Prof. H.B., on roburite explosions, 139.
Drying house for gun-cotton, 122.
Dynamite, efficiency of, 118. frozen dynamite, 116. gelatine dynamite,
119. properties of kieselguhr dynamite, 116. Reid & Borland's carbo-
Crusher gauge, 284.
Cundill, Colonel, classification of dynamites, 112.
Danger area, 5.
Dangers in the manufacture of gun-cotton, 85.
Decomposition of cellulose, 54.
Definition of explosives in Order of Council (Explosives Act), 1.
Determination of N_{2}O_{4} in nitric acid, 24.
Determination of strength of H_{2}SO_{4}, 25.
Determination of relative strength of explosives, 272.
Detonators, 163.
Di-nitro-toluene, 138.
Dipping cotton in manufacture of gun-cotton, 60.
Divers and Kawakita on the fulminates, 159.
Dixon, Prof. H.B., on roburite explosions, 139.
Drying house for gun-cotton, 122.
Dynamite, efficiency of, 118. frozen dynamite, 116. gelatine dynamite,
119. properties of kieselguhr dynamite, 116. Reid & Borland's carbo-
Page 320
dynamite, 119. Rhenish dynamite, 119. various kinds of, 119.
E.C. powder, 186.
Electronite, 151.
Emmensite, 195.
Equation of formation of nitro-glycerine, 16.
Equation of formation of nitro-cellulose, 50.
Exploders, electric, 167.
Explosion gases of dynamite, 19. nitro-glycerine, 18. gun-cotton, 55.
roburite, 139.
Exudation test gelatines, 257.
Faversham powder, 147.
Favier's explosive, 149.
Field on celluloid, 93, 99.
Firing-point of explosives, 247.
Filite, 180.
Filtering nitre-glycerine, 37.
Flameless explosives, 89, 138, 144.
E.C. powder, 186.
Electronite, 151.
Emmensite, 195.
Equation of formation of nitro-glycerine, 16.
Equation of formation of nitro-cellulose, 50.
Exploders, electric, 167.
Explosion gases of dynamite, 19. nitro-glycerine, 18. gun-cotton, 55.
roburite, 139.
Exudation test gelatines, 257.
Faversham powder, 147.
Favier's explosive, 149.
Field on celluloid, 93, 99.
Firing-point of explosives, 247.
Filite, 180.
Filtering nitre-glycerine, 37.
Flameless explosives, 89, 138, 144.
Page 321
Formation of white matter in the nitration of N.G., 39.
Forcite, 119.
France, 82.
Free fatty acid in glycerine, 39, 235.
Freeing nitric acid from N_{2}O_{4}, 25.
Freezing-point of N.G., 21.
French Commission on Ammonium Nitrate, 142.
Fulminates constitution, 159.
Fulminate of mercury, 159, 240.
Fulminate of silver, 161.
Fuses, various kinds of, 166.
Gases formed by the decomposition of nitro-glycerine, 18.
Gelatine explosives, analysis of, 199.
Glycerine, analysis of, 233. formula of, 16. nitration of, 23.
Greiner's powder, 190.
Gun-cotton, analysis of, 212. boiling, 64. complete series of, 52, 54.
compressing, moulding, and packing, 67, 77, 78. dipping and steeping the
cotton, 60. drying the cotton, 58. granulation of, 79. manufacture of, 57.
Forcite, 119.
France, 82.
Free fatty acid in glycerine, 39, 235.
Freeing nitric acid from N_{2}O_{4}, 25.
Freezing-point of N.G., 21.
French Commission on Ammonium Nitrate, 142.
Fulminates constitution, 159.
Fulminate of mercury, 159, 240.
Fulminate of silver, 161.
Fuses, various kinds of, 166.
Gases formed by the decomposition of nitro-glycerine, 18.
Gelatine explosives, analysis of, 199.
Glycerine, analysis of, 233. formula of, 16. nitration of, 23.
Greiner's powder, 190.
Gun-cotton, analysis of, 212. boiling, 64. complete series of, 52, 54.
compressing, moulding, and packing, 67, 77, 78. dipping and steeping the
cotton, 60. drying the cotton, 58. granulation of, 79. manufacture of, 57.
Page 322
Abel's method, 57. Stowmarket, 57. Waltham Abbey, 71. products of
decomposition of, 55. properties of, 54. pulping, 65. washing, 63. as a
mining explosive, 56.
Guttmann's nitric acid plant, 45.
Guttmann's heat test, 256.
Handy's method for determining moisture in dynamite, 197.
Hannah, Dr N., on roburite explosion gases, 139.
Heat developed by explosives containing nitro-glycerine, &c., 288.
Heat test, Abel, 249.
Hellhoffite, 152.
Henrite powder, 191.
Hollander, 65.
Horsley's apparatus, 248.
Hydro-extractors for wringing out gun-cotton, 62.
Impurities in commercial glycerine, 39, 233.
Impurities in fulminate, 240. nitro-glycerine, 38. picric acid, 231.
decomposition of, 55. properties of, 54. pulping, 65. washing, 63. as a
mining explosive, 56.
Guttmann's nitric acid plant, 45.
Guttmann's heat test, 256.
Handy's method for determining moisture in dynamite, 197.
Hannah, Dr N., on roburite explosion gases, 139.
Heat developed by explosives containing nitro-glycerine, &c., 288.
Heat test, Abel, 249.
Hellhoffite, 152.
Henrite powder, 191.
Hollander, 65.
Horsley's apparatus, 248.
Hydro-extractors for wringing out gun-cotton, 62.
Impurities in commercial glycerine, 39, 233.
Impurities in fulminate, 240. nitro-glycerine, 38. picric acid, 231.
Page 323
Ketones as solvents for pyroxyline, 101.
Kieselguhr dynamite, 112.
Kinetite, 145.
Kjeldahl method of determining nitrogen, 227.
Le Bouchet, manufacture of gun-cotton at, 78.
Lead cylinders for testing strength of explosives, 281.
Lenk's improvements in gun-cotton manufacture, 49.
Lewes on the pressure of cordite, 175.
Leibert's treatment of nitro-glycerine, 30.
Lightning conductors for danger buildings, 10.
Liquefaction test for gelatine, 257.
Lodge on lightning conductors, 8.
Lowering of freezing-point of N.G., 21.
Lungé's nitrometer, 219.
Lydite, 156.
Manufacture of gun-cotton, 57.
Kieselguhr dynamite, 112.
Kinetite, 145.
Kjeldahl method of determining nitrogen, 227.
Le Bouchet, manufacture of gun-cotton at, 78.
Lead cylinders for testing strength of explosives, 281.
Lenk's improvements in gun-cotton manufacture, 49.
Lewes on the pressure of cordite, 175.
Leibert's treatment of nitro-glycerine, 30.
Lightning conductors for danger buildings, 10.
Liquefaction test for gelatine, 257.
Lodge on lightning conductors, 8.
Lowering of freezing-point of N.G., 21.
Lungé's nitrometer, 219.
Lydite, 156.
Manufacture of gun-cotton, 57.
Page 324
Manufacture of nitro-glycerine, 17. cordite, 169. roburite, 140.
fulminates, 162. tonite, 84. di-nitro-benzene, 138. nitro-starch, 103.
celluloid, 91.
Majendie (Col. Sir V.D.), report on a picric acid explosion, 155.
Maximite, 191.
Maxim's detonator mixture, 165.
M'Robert's mixing machine, 126.
Mechanical equivalent of explosives, 273.
Melinite, 156.
Mono-nitro-glycerine, di-nitro-nitro-glycerine, 41.
Moulding gun-cotton, 77.
Mounds for protection of danger buildings, 6.
Mortar for ballistic tests, 275.
Mowbray on use of compressed air, 15.
Mühlhäusen on nitro-starch, 4, 5, 103.
Nathan's nitrator, 32.
Nitric peroxide in N.G., 24.
Nitration products of cellulose, 52, 54.
fulminates, 162. tonite, 84. di-nitro-benzene, 138. nitro-starch, 103.
celluloid, 91.
Majendie (Col. Sir V.D.), report on a picric acid explosion, 155.
Maximite, 191.
Maxim's detonator mixture, 165.
M'Robert's mixing machine, 126.
Mechanical equivalent of explosives, 273.
Melinite, 156.
Mono-nitro-glycerine, di-nitro-nitro-glycerine, 41.
Moulding gun-cotton, 77.
Mounds for protection of danger buildings, 6.
Mortar for ballistic tests, 275.
Mowbray on use of compressed air, 15.
Mühlhäusen on nitro-starch, 4, 5, 103.
Nathan's nitrator, 32.
Nitric peroxide in N.G., 24.
Nitration products of cellulose, 52, 54.
Page 325
Nitro-glycerine, analysis of, 198. properties, 17. nitration, 23. separation,
35. washing, 37. uses of, 41. manufacture of, 17.
Nitro-benzene, properties and manufacture of, 132, 137.
Nitro-cellulose, 2, 47, 60, 212.
Nitro-jute, 5, 107.
Nitro-mannite, 4, 109.
Nitro-naphthalene, 148.
Nitro-starch, 4, 103.
Nitro-toluene, 132.
Nitrated gun-cotton, 83.
Nitrogen, determination of, Lungé method, 219.
Champion and Pellet's, 223.
Schultze-Tieman, 224.
Kjeldahl-Chenel's, 227.
percentages of in various explosives, 228.
Nitrometers, Lungé, Horn's, &c., 220, 222.
Nobel's ballistic test, 274.
Noble's pressure gauge, 282. experiments on cordite, 172.
Normal powder, 191.
35. washing, 37. uses of, 41. manufacture of, 17.
Nitro-benzene, properties and manufacture of, 132, 137.
Nitro-cellulose, 2, 47, 60, 212.
Nitro-jute, 5, 107.
Nitro-mannite, 4, 109.
Nitro-naphthalene, 148.
Nitro-starch, 4, 103.
Nitro-toluene, 132.
Nitrated gun-cotton, 83.
Nitrogen, determination of, Lungé method, 219.
Champion and Pellet's, 223.
Schultze-Tieman, 224.
Kjeldahl-Chenel's, 227.
percentages of in various explosives, 228.
Nitrometers, Lungé, Horn's, &c., 220, 222.
Nobel's ballistic test, 274.
Noble's pressure gauge, 282. experiments on cordite, 172.
Normal powder, 191.
Page 326
Oleic acid in glycerine, 236.
Orsman on roburite, 142.
Oxonite, 152.
Oxy-cellulose, 102.
Packing gun-cotton, 78. dynamite, 116.
Page's regulator, 260.
Panclastite, 152.
Percentage composition of nitro-glycerine, 18.
Perkin on magnetic rotation of nitro-glycerine, 19.
Phenol, tri-nitro-phenol, 152.
Picric acid, 152, 231. powders, 157, 189.
Picrates, 154, 231.
Polarised light and nitro-cellulose, 218.
Position of the NO_{2} group in nitro-explosives, 2, 3, 16.
Prentice's nitric acid plant, 43.
Pressure gauge, 282.
Primers of gun-cotton, 166.
Orsman on roburite, 142.
Oxonite, 152.
Oxy-cellulose, 102.
Packing gun-cotton, 78. dynamite, 116.
Page's regulator, 260.
Panclastite, 152.
Percentage composition of nitro-glycerine, 18.
Perkin on magnetic rotation of nitro-glycerine, 19.
Phenol, tri-nitro-phenol, 152.
Picric acid, 152, 231. powders, 157, 189.
Picrates, 154, 231.
Polarised light and nitro-cellulose, 218.
Position of the NO_{2} group in nitro-explosives, 2, 3, 16.
Prentice's nitric acid plant, 43.
Pressure gauge, 282.
Primers of gun-cotton, 166.
Page 327
Properties of dynamite, 116. gelatine compounds, 130.
Pulping gun-cotton, 65.
Pyroxyline for celluloid, 96. solvents for, 101.
Quinan's foot-pound machine, 280.
Raoult's law and N.G., 21.
Reworked gun-cotton, 78.
Rhenish dynamite, 119.
Roburite, properties and manufacture of, 138. Bedson's report on, 140.
Orsman on gases produced by explosion of, 142.
Romit, 148.
Sarrau and Vieille, gases obtained from ignition of dynamite, 19.
Sayers, 50.
Scheme for analysis of explosives, 213.
Schultze's powder, 183.
Schultze-Tieman method of determining nitrogen, 224.
Securite, 144.
Pulping gun-cotton, 65.
Pyroxyline for celluloid, 96. solvents for, 101.
Quinan's foot-pound machine, 280.
Raoult's law and N.G., 21.
Reworked gun-cotton, 78.
Rhenish dynamite, 119.
Roburite, properties and manufacture of, 138. Bedson's report on, 140.
Orsman on gases produced by explosion of, 142.
Romit, 148.
Sarrau and Vieille, gases obtained from ignition of dynamite, 19.
Sayers, 50.
Scheme for analysis of explosives, 213.
Schultze's powder, 183.
Schultze-Tieman method of determining nitrogen, 224.
Securite, 144.
Page 328
Separation of nitro-glycerine from mixed acids, 35.
Shimose, 156.
Silver test for glycerine, 233.
Smokeless powders, 168.
Smokeless diamond, 190.
Snyder's powder, 193.
Sobrero discovered nitro-glycerine, 14.
Sodium nitrate, analysis of, 239.
Soluble and insoluble nitro-cellulose, 51.
Solubility of nitro-glycerine, 20.
Solvents for soluble gun-cotton, 52, 101.
Solubility test for gun-cotton, 214.
Specific gravity of explosives, 270.
Sprengel's explosives, 151.
Stowmarket, manufacture of gun-cotton at, 57.
Sulphuric acid, determination of strength of, 24.
Sy on test for nitro-cellulose, 269.
Shimose, 156.
Silver test for glycerine, 233.
Smokeless powders, 168.
Smokeless diamond, 190.
Snyder's powder, 193.
Sobrero discovered nitro-glycerine, 14.
Sodium nitrate, analysis of, 239.
Soluble and insoluble nitro-cellulose, 51.
Solubility of nitro-glycerine, 20.
Solvents for soluble gun-cotton, 52, 101.
Solubility test for gun-cotton, 214.
Specific gravity of explosives, 270.
Sprengel's explosives, 151.
Stowmarket, manufacture of gun-cotton at, 57.
Sulphuric acid, determination of strength of, 24.
Sy on test for nitro-cellulose, 269.
Page 329
Temperature of nitration of nitro-glycerine, 29.
Thomson's patents, 73.
Toluene, 146.
Tonite, 84, 146. analysis of, 205. fumes from, 85.
Treatment of waste acids, 43.
Trench's fire-extinguishing compound, 88.
Trebouillet and De Besancele on celluloid manufacture, 92.
Tri-nitro-cresol, 158.
Tri-nitro-toluene, 146.
Tri-nitro-phenol, 152.
Tri-nitro-glycerine, 2, 14.
Troisdorf powder, 191, 192.
Turpin's melinite, 156.
U.S. naval powder, 180.
Uses of celluloid, 91, 93, 102.
Uses of collodion-cotton, 90.
Thomson's patents, 73.
Toluene, 146.
Tonite, 84, 146. analysis of, 205. fumes from, 85.
Treatment of waste acids, 43.
Trench's fire-extinguishing compound, 88.
Trebouillet and De Besancele on celluloid manufacture, 92.
Tri-nitro-cresol, 158.
Tri-nitro-toluene, 146.
Tri-nitro-phenol, 152.
Tri-nitro-glycerine, 2, 14.
Troisdorf powder, 191, 192.
Turpin's melinite, 156.
U.S. naval powder, 180.
Uses of celluloid, 91, 93, 102.
Uses of collodion-cotton, 90.
Page 330
Vaseline, 208.
Vielle poudre, 190.
Volney's powder, 148.
Von Foster's powder, 191.
Walsrode powder, 188.
W.A. powder, 182.
Waltham Abbey, manufacture of gun-cotton at, 71. manufacture of
cordite at, 169.
Walke's pressure gauge results, 289.
War Office experiments with cordite, 173.
Washing gun-cotton, 63. nitro-glycerine, 37.
Waste acids from nitro-glycerine, 41, 226.
Weltern powder, 191.
Werner & Pfleiderer's mixing machine, 124.
Whirling out the acids from gun-cotton, 62.
Will's test for nitre-cellulose, 261.
Wood pulp, 126.
Vielle poudre, 190.
Volney's powder, 148.
Von Foster's powder, 191.
Walsrode powder, 188.
W.A. powder, 182.
Waltham Abbey, manufacture of gun-cotton at, 71. manufacture of
cordite at, 169.
Walke's pressure gauge results, 289.
War Office experiments with cordite, 173.
Washing gun-cotton, 63. nitro-glycerine, 37.
Waste acids from nitro-glycerine, 41, 226.
Weltern powder, 191.
Werner & Pfleiderer's mixing machine, 124.
Whirling out the acids from gun-cotton, 62.
Will's test for nitre-cellulose, 261.
Wood pulp, 126.
Page 331
Xylonite Company's process, 96.
Zenger's lightning conductors, 11.
Printed at THE DARLEN PRESS, Edinburgh.
Zenger's lightning conductors, 11.
Printed at THE DARLEN PRESS, Edinburgh.
Page 332
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