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Title: The Quarterly Journal of Science, Literature and the Arts, July-
December, 1827

Author: Various

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*** START OF THE PROJECT GUTENBERG EBOOK THE
QUARTERLY JOURNAL OF SCIENCE, LITERATURE AND THE

ARTS, JULY-DECEMBER, 1827 ***

TRANSCRIBER'S NOTE
See Transcriber's Endnote for details of this transcription. Journal July-Dec., 1827: Part 1.
Part 2.

THE

Q U A R T E R LY J O U R N A L
OF

SCIENCE,
L I T E R AT U R E , A N D A R T .

J U LY T O D E C E M B E R , 1 8 2 7 .

LONDON:
HENRY COLBURN, NEW BURLINGTON-STREET.

MDCCCXXVII.

CONTENTS. ◊

July–Oct. 1827.

On the Beauties contained in the Ovals and in the elliptic
Curves, both simple and combined, generated from the
same Figure or Disk. By R. R. R EINAGLE , Esq., R.A. 1
On the Art of forming Diamonds into Single Lenses for
Microscopes. By Mr. A. P RITCHARD . 15
Analysis of a newly-discovered Spring, at Stanley, near
Wakefield. By Mr. W ILLIAM W EST . 21
Observations on the State of Naval Construction in this
Country. 25
On Malaria. No. II. By Dr. M AC C ULLOCH , M.D., F.R.S.,
&c. 39
Dr. T URNER ’s Elements of Chemistry, reviewed 60
Experiments on Audition. Communicated by Mr. C.
W HEATSTONE . 67
On the Petromyzon Marinus 72
Observations upon the Motion of the Leaves of the Sensitive
Plant 76
Experiments on the Nature of L ABARRAQUES ’ Disinfecting
Soda Liquid. By M. F ARADAY , F.R.S., Cor. Mem. Roy.
Acad. Sci. Paris, &c. 84
Hieroglyphical Fragments, with some Remarks on English
Grammar. In a Letter to Baron William Von H UMBOLDT .
By a Correspondent 92

Dr. M AC C ULLOCH ’s ‘Malaria; an Essay on the Production
and Propagation of this Poison,’ reviewed 100
Account of a New Genus of Plants, called Reevesia. By J.
L INDLEY , Esq., F.L.S., &c. &c. 109
A STRONOMICA AND N AUTICAL C OLLECTIONS .
i. F RESNEL on the Undulatory Theory of Light 113
ii. Rule for the Correction of a Lunar Observation. By Mr.
W. W ISEMAN , of Hull 135
‘De l’Influence des Agens Physiques sur la Vie. Par W. F.
E DWARDS , D.M.’ &c., reviewed 137
Account of Professor C ARLINI ’s Pendulum Experiments on
Mont Cenis 153
Analysis of ‘Transactions of the Horticultural Society. Vol.
vii. Part I.’ 159
On the Recent Elucidations of Early Egyptian History 176
Proceedings of the Horticultural Society. 190

MISCELLANEOUS INTELLIGENCE.
I. M ECHANICAL S CIENCE .
1 On the Combined Action of a Current of Air, and the
Pressure of the Atmosphere 193
2 Considerations relative to Capillary Action 194
3 Novel Use of the Plough 197
4 Discovery of Rocks under the Surface of the Sea 198
5 Paper to resist Humidity ib.
6 Professor Amici’s Microscopes ib.
II. C HEMICAL S CIENCE .
1 On the Specific Heat of Gases 200
2 On the Incandescence & Light of Lime 201
3 Evolution of Heat during the Compression of Water
ib.
4 On Electrical Excitation ib.
5 Magnetic Repulsion 202
6 Diminished Solubility of Substances by Heat ib.
7 Composition of Cyanic Acid 203
8 Iodous Acid 204
9 Manganesic Acid ib.
10 Heavy Muriatic Ether, and Chloric Ether ib.
11 Test for the Presence of Nitric Acid 205
12 Peculiar Formation of Nitre ib.
13 Experiments on Fluoric Acid and Fluates ib.
14 Crystallization of Phosphorus 206
15 Solution of Phosphorus in Oils ib.
16 On the Inflammation of Powder, when struck by
Brass 207
17 Cementation of Iron by Cast Iron ib.

18 On the Preparation of Ferro-prussiate of Potash ib.
19 Sulphocyanide of Potassium in Saliva 208
20 Decomposition of Sulphate of Copper, by Tartaric
Acid ib.
21 Separation of Arsenic from Nickel, or Cobalt 209
22 Chemical Researches into Certain Ancient
Substances 209
23 Compounds of Gold 210
24 On the Bitter Substance produced by the Actions of
Nitric Acid on Indigo, Silk, and Aloes ib.
25 On the Existence of Crystals of Oxalate of Lime in
Plants 214
26 Fallacy of Infusion of Litmus as a Test ib.
27 Tests for the Natural Colouring Matter of Wine 215
28 Test of the Presence of Opium ib.
29 Denarcotized Laudanum ib.
30 Extraction of Morphia from Dry Poppy Heads 216
31 Preparation of Morphia ib.
32 Easy Method of Obtaining Meconic Acid 217
33 On a New Vegetable Acid ib.
34 Altheine, a New Vegetable Principle ib.
35 Rheine, a New Substance from Rhubarb 218
36 On Dragon’s Blood, and a New Substance which it
contains ib.
37 Purification of Madder 219
38 On Indigo, and Indigogene 220
39 On the Mutual Action of Ethers, and other
Substances 221
40 Faraday’s Chemical Manipulation ib.
III. N ATURAL H ISTORY .
1 On the Supposed Influence of the Moon 222

2 Luminous Appearances in the Atmosphere ib.
3 On the Determination of the Mean Temperature of the
Air 223
4 Indelible Writing ib.
5 Peculiar Crystals of Quartz ib.
6 Native Iron not Meteoric 224
7 Native Argentiferous Gold 225
8 Prothéeïte, a New Mineral 226
9 Volcanic Bisulphuret of Copper ib.
10 Fall of the Lake Souwando, in Russia 227
11 Vegetable Torpor in the Root of the Black Mulberry
Tree 228
12 Method of increasing the Odour of Roses ib.
13 Pine Apples ib.
14 Mode of Condensing Vegetable Substances for
Ship’s Provisions 229
15 Rewards for the Discovery of Quinia, and for
Lithotrity ib.
16 Upon the Gaseous Exhalations of the Skin 230
17 Effects of Galvanism in Cases of Asphyxia by
submersion ib.
18 Recovery from Drowning 231
19 Preservation of Cantharides ib.
20 Chloride of Lime in cases of Burns ib.
21 Cure of Nasal Polypi 232
22 Bite of the Viper ib.
23 Experiments on the Poison of the Viper ib.
24 Destruction of Moles ib.
25 On growing Salad Herbs at Sea 233
26 Chinese Method of Fattening Fish 234

Meteorological Diary for the Months of June, July, and
August, 1827 236

TO OUR READERS AND CORRESPONDENTS.

The drawings, illustrating the construction of a Blow-pipe, are not
sufficiently accurate to enable us to publish them. Our Correspondent will
observe that we have noticed another part of his letter.

We regret that we are unable to offer our Correspondent, upon the subject
of Gas Works, any precise information. There can be no doubt that an
atmosphere tainted by coal gas is injurious to animal and vegetable life, but
much will depend upon the extent of the contamination, and other causes,
of which our limits prevent mention. To say nothing of danger from fire and
from explosion, it has always been matter of surprise to us that gas-works
are tolerated by the government in close and confined situations—that the
Thames is suffered still to be polluted with their offal, and that they are
sometimes placed close by the road side, (as at Brentford,) to the nuisance
of every one who passes. These matters want looking into.

Q. will find an answer to his question, in the “Gazette of Health” for last
July.

F. R. S. must remain unanswered till after St. Andrew’s Day.

Dr. Heinecken’s paper is disposed of as he desired.

Mr. B RANDE and Mr. F ARADAY will commence their Lectures and
Demonstrations in Theoretical and Practical Chemistry, in the Laboratory of
the Royal Institution, on Tuesday, the 9th of October, at Nine in the
Morning precisely. Further particulars, and a Prospectus, may be obtained at
the Royal Institution, 21, Albemarle-street, or by application to the
Lecturers.

In the Press—A C OLLECTION OF C HEMICAL T ABLES , for the use of
Students, in Illustration of the Theory of Definite Proportionals, in which
are shewn the Equivalent Numbers of the Elementary Substances, with the
Weights and Volumes in which they combine, together with the
Composition of their most important Compounds, and the Authorities for
their Analysis. By W ILLIAM T HOMAS B RANDE .

THE

Q U A R T E R LY J O U R N A L
OF

S CI E NCE , L I T E RAT URE , AND ART.
JULY– OCT. 1 82 7.

On the Beauties contained in the Oval, and in the Elliptic Curves, both
simple and combined, generated from the same Figure or Disk. By R. R.
Reinagle, Esq., R.A. ◊

Being the subject of a Discourse delivered at the Royal Institution of Great Britain.

A FTER an apposite discourse to introduce the subject, the first course taken,
was to demonstrate the advantages of understanding the right use of
geometrical terms in our descriptions of the varieties of shape, both in
nature and art.
Every thing deserving the title of beautiful, and every grand object,
assume an outline of definite character: these are to be found in the different
classes of geometrical figures; the former in undulating lines of elliptic
curves, and grandeur in angular dispositions of figure. All motion assumes a
curved direction1. The primary and leading object of the discourse was to
prove the fact of original beauty: and that a curved line was beautiful in an
abstract point of view, free from all associations. For this purpose there
were designed many diagrams on large black painted boards. [p002]
The explanation commenced with six or more parallel lines at equal
distances, and equal length, in an horizontal position to the eye of the
audience, Fig. 1; and another set of the same number of lines drawn

perpendicular, Fig. 2: these were demonstrated to possess not the slightest
character or principle of beauty in them, either as separate lines, or
collectively, however many.

Fig. 1. Fig. 2.

Fig. 3. Fig. 4.
The next diagram consisted of six or more radiating lines from a centre,
Fig. 3, and a corresponding number in an horizontal direction, but of
unequal quantities; they diminished like a flight of steps, Fig. 4. It was then
shown that the first means of combining the six or more lines, which had
been first drawn, so as to please the eye, without creating any geometrical
figure, was the radiating principle. Our eye not only can tolerate that union

of lines, but receive the impression as pleasing in character; while all lines
parallel to each other, being right [p003] lines, and viewed as a flight of steps,
or pile of planks, opposite the observer, are disagreeable. Upon the former
principle it is, that the rays of the sun, and rays of light generally, are so
attractive and beautiful. It is from this circumstance that right lines drawn in
an inclined position to the plane of the picture, derive an interest from the
angles engendered through the imagination.

Fig. 5. Fig. 6. Fig. 7. Fig. 8.
To follow up the principle by regular steps, and to open a clear view of
the laws of beauty in lines, there were traced some inclined right lines (Fig.
5), with a regular set of right angles upon it, like the stems of leaves on each
side. This exhibited no sort of beauty, nor any other advantage than mere
combinations of formal angles. The next diagram (Fig. 6) was an inclined
line as before, with similar angular projecting stems, to which were added
elliptic curves on the upper side of each branch, that produced the form of a
leaf. Fig. 7 was another inclined line, having oval curves upon it. Both these

were shown to possess principles approaching to beauty, by progressive
advances in combination and original structure. Fig. 8 was an inclined line
with the oval curves upon it; to which a similar addition of elliptic curves
were adjoined to the stems, [p004] as in Fig. 6. This addition made a new
advance towards beauty. Fig. 9 commenced a more perfect principle of
beauty, having an elliptic stem with oval branches rising from it, as in the
others. If to this, the principle of gradation had been given, the eye would
prefer it; I mean, by a scale of increase from the top to the bottom of the
projecting stems: and if there had been superadded the external contour of a
lengthened egg, like the form of a sage leaf, we should, step by step,
advance into the region of beautiful character of exterior shape. Fig. 10 is a
retrograde, showing how uncongenial angular forms are to curved lines,
when producing ornament; at least how little our eye can bear the angular
projections from the elliptic or oval turned stem. Fig. 11 was a curve of
exactly the same disk, with the same oval stems, to which a small
serpentine addition was made, expressing a leaf. Of all the last seven
diagrams, this abounded with the greatest portion of beautiful lines, and is
indisputably the most agreeable and beautiful. Combinations are like
numericals; many of these forms, placed together with judgment and
discretion, will attract us from the larger proportion of beauty that meets the
eye at once, like a head of beautiful hair: one hair, however gracefully bent,
cannot impress us like an entire lock of the hair; nor will this [p005] curl
charm us as the whole will on the human head. We owe to construction and
combination all our pleasurable feelings of beauty: no person is allured by a
single feature of any species of objects: but a thousand, or a million, arouses
our anxious notice. Thus, the last diagram of the elliptic stem and the
foliage upon it, exhibited, by the continuity of curved lines, the greatest
approach to beauty, of all the figures presented to the notice of the audience.

Fig. 9.

Fig. 10.

Fig. 11.

These preliminary designs opened the way for richer combinations; but
the subject affording such an immense field of variety, I confined myself to
the narrowest limits, and to one oval disk of seven inches transverse
diameter, from which seven different designs were shown on paper. The
first had a variety of serpentine lines placed at random, all produced by the
disk of the oval just named, and the confluent lines of two such, placed side
by side, or end to end, Fig. 12; which oval disk was put upon the lines to
prove the construction. These lines, without expressing or forming any sort
of figure, exhibit a set of elegant curves, of varied quantities of convex and
concave, with which our eye will be more pleased than any set of right lines
similarly distributed, as in Fig. 13, which follows. [p006]

Fig. 12.

Fig. 13.

Fig. 14.
Two other diagrams were placed before the company, each a circle of 12
ovals, from the same disk, revolved upon an axis, resting upon one end of
the transverse diameter, (the length-ways of the oval,) which figure in the
skeleton was a duodecagon. Fig. 14 is one of the diagrams; the ovals
folding regularly over each other. By suppressing the continuity of the oval
disk, where the lines would traverse, a very pleasing figure [p007] is created.
It may be easily converted into foliage, and can be amazingly varied in
principle, by having fewer ovals, and making them revolve upon an arm or
continuation of a line from the transverse diameter. Fig. 15 is the same
diagram, with all the oval lines described, which forms a figure of elegant
intricacy; each member, or curvilinear subdivision, assumes a most
agreeable shape: the whole, at the first sight, does not carry the evidence of
being generated from the same disk. These agreeable figures may be varied
to an extraordinary extent: the two that were presented were mere examples
of some of the numerous changes that any given oval disk may create.

Fig. 15.

Fig. 16.

Fig. 17.
The objects next presented, were three vases of very dissimilar
appearance, all produced from the same diagram of the oval; each in a
separate drawing. The first was like a Greek vase with handles; its character
established by employing certain proportions of quantities, in seven parts.
The body has four parts, the foot or pedestal one; the neck two. The handles
were regulated in the position and projection by lines drawn from the
bottom of the vase, through the ovals which compose the outline of the two
sides; and passing through the transverse diameter. These handles were
made from an oval that was the length of half the line of the transverse
diameter, Fig. 16. The skeleton of angles that [p008] govern the shape of this
vase, is a very pretty figure of itself. The form does not proceed from any
caprice of irregularity, but is consistent with rational organization, and
symmetrical proportions. The figure of the plate sufficiently describes the
mode of making the diagram without entering into the detail. Fig. 17
represents a tazza with handles: the same disk is apparent, by the dotted
lines that made the first vase. The ovals [p009] are placed right and left of a
central perpendicular line, dividing the cup in two parts; the transverse
diameters meet in one line parallel to the base of the tazza; a dotted outline
expresses the angular position of the handles: the concave lip of the tazza is
made by the same oval disk, whose transverse diameter leads to the under

line of the folding edge of the cup. The leg of the tazza is produced by the
same small disk that served for the handles of the first vase. The body of the
vase and the leg form two equal parts; the whole upper extent ought to be
seven parts, so that it is seven and two2; the width of the base of the leg
measures two parts, and the altitude three, of the seven parts. These
proportions cannot produce any other than agreeable appearances, apply
them as we may.

The third vase, exhibited an Hebe cup,
with a handle, which presented a totally
different appearance in form to the two
previous ones. It was proportioned by
similar principles: the larger disk made the
body, inclined right and left upon the end of
the oval. The neck and the leg were both
made from the smaller oval disk; the dotted
lines to the ovals of the leg sufficiently show
the fact. The handle and concave lip of the
cup were made by an application of the same
disk. The altitude contained four parts. The
body two parts, the leg one part, and the
neck one other part; the handle rises one-
eighth above: every portion of this figure is
created by the two disks previously named.
The foliage rises from below and descends
from above, one-fourth of the whole height
of the body [p010] to the commencement of
the concavity of the neck, where the beading
runs round.
Fig. 18. I remarked, that by adhering to regular
proportional quantities of 1 and 2, 3 and 5, 2
and 5, 7 and 5, 7 and 2, &c., and using elliptic disks or curves, very great
beauties are derived.

Fig. 19.

Fig. 20.
A skeleton of the tazza in angles was drawn on a black painted board,
together with oval disks placed upon those lines, which clearly demonstrated
the whole system of the construction. The explanation of these various
diagrams necessarily involved a circumstantial description of each created
figure, which were thoroughly analysed. Quantity and variety were
particularly dwelt upon, as absolutely necessary to the production of perfect
beauty; equalities being unfriendly to that symmetry which accords with
nature. Some other diagrams were drawn, to show the inelegant appearance
of radiating lines from the concave or convex half of an oval or an ellipse,
Fig. 19: but by drawing another convex half of an oval, and placing those
lines as tangents, greater beauty was formed by the alternate changes and
varieties of inclination of each tangent, Fig. 20. This was capable of an
immediate adaptation to elegant vegetation; [p011] a few convex and concave
elliptic curves added to each tangent, produced an ear of barley, or an ear of
rye, the elegant construction of which, is rarely noticed in our remarks on
nature, Fig. 21.

Fig. 21.
The discussion on these various designs being concluded, some important
compositions of three great and renowned painters were produced, to
corroborate what had been advanced in support of the native beauty of the
oval and ellipse. Raphael’s grand composition of the dispute on the
Sacrament is in three grand oval curves.
The Doctors of the Church on the ground plan are ranged in an oval
convex line; and the heavenly Choirs engage two concave oval shapes of the
same proportion, but of unequal quantities. This is also a proof of a
composition of parts, bearing two to one.
The facility of expressing such a composition, by being geometrical, is
extremely easy.
The second illustration was the Aurora, by Guido, of the Aldobrandini
palace. This was pointed out to depend upon an oval curve, and continued
curvilinear details: the striking beauty of this fine composition is owing to its
great and simple elliptic curve, which includes the whole group; the attendant
hours have the principle of radiating to a centre of the oval: thus harmonizing
and uniting forms congenial both to principle and nature.
The third grand composition was by Rubens, the Coronation ceremony of
Mary de Medicis, one of the grand Luxemburg pictures.
This very fine composition is contained in an oval concave [p012] curve,
and the figures in several points radiate to a centre. Some of the group pass
the great leading line, but only to the degree and with the licence that a genius
can effect, which destroys the too great, and the too palpable construction of
the composition. The allegorical figures of Fame and Genius hovering over

the royal personage, establish a centre to the oval, which prevents a void that
would have been weak in the composition.
Three designs were next produced from Etruscan vases, to carry the
evidence further, and to show the original source of the demonstrations of
beauty in Grecian art. One was a charioteer driving a pair of magnificent
horses of the highest spirit, Fig. 22. The composition is elliptic, and
serpentine within.

Fig. 22.
The youthful conductor of the steeds is in a crescent or boat-shaped car,
and his form is elegantly bent to meet the action and motion; his mantle flows
behind in curved and serpentine folds, expressing the wind occasioned by the
velocity of action. A more graceful or beautiful group and composition cannot
be imagined.
The next design was a female in an elegant and very gentle serpentine
action of the figure. Every portion of the outlines was elegant, from the
varied succession of convexity and concavity; not a single angle could be
traced throughout the whole [p013] of this beautiful creature. She held in her
left arm a very handsome oval vase; and in the other a sort of scarf with

ribands, all serpentine in form. By her side is placed a young man selected
from another Etruscan design.

Fig. 23.
The line of this figure was the outline of an ellipse; it is perfection in every
respect; and the grace was shown to depend upon gentle curved lines of
convex and concave, alternately blended, and confluent. The motion of ships
at sea is described in gentle elliptic curves; the wings and plumage of birds
assume the oval and elliptic curves; all the fibres of their feathers have that
form; some flattened, others more rounded: the pine-apple and numberless
fruits have all an oval character of outline.
Many take the character of eggs, pointed at one end, and large and blunt at
the other extremity. The leaves of trees [p014] have the oval shape more than
any other; the bend of the branches, and the whole external form of many
trees is oval.

There is no form of created things which may not be found to correspond
in all its dependent shapes to ovals and ellipses of various disks, even objects
which at first sight seem to contradict the possibility of meeting this system.
The lecture was closed by some extracts and quotations from Lomazzo,
Dryden, Hogarth, Du Fresnoy, and the Abbé du Bos; the tendency of which
was to show that lines had been mentioned, and had been written upon
without any explanation given that could lead to certain conclusions. That all
these authors attributed to supreme genius alone, and something of the
divinely inspired character in artists, the power to produce those
indescribable lines that affect the human eye so strongly. These lines I
described as belonging to the oval and the ellipsis, and the confluent lines by
conjunction and combination; that these indescribable lines, which from Plato
to Dryden had never been detected or obtained a name; that puzzled all
equally alike, are those alone I attempted, and I believe proved in this lecture,
to be the elliptic combinations.
I stated that the great Greek artists confined themselves to certain rules and
principles of unerring consequences in the production of beauty, grace, or
grandeur in their figures; that all their compositions depended upon the same
species of rule and order. I pointed out, that fashion is in all countries the
destroyer of taste, that it unfits the mind for fixed principles; that where it
dominates, there taste will be always fluttering and never settle, nor have a
sure dominion. The Greeks, having no such vile tormentor to divert them
from a pure course in their progress, arrived at the summit of perfection in
every scientific pursuit, by following sure principles as their guides, and by
never abandoning a path traced by nature, and matured by the most sublime
philosophy.

1 A great number of geometrical diagrams were exhibited, from a single line, to angles,
squares, oblongs, circles, ovals, cones, cylinders, spiral lines, and various serpentine lines, &c.
2 The whole extent of the tazza, including the projection of the handles, should be seven parts;
and the height of the vase two of such seven parts.

[p015]

On the Art of forming Diamonds into single Lenses for Microscopes.—By
Mr. A. Pritchard. ◊
[Communicated by Dr. G ORING .]

O F the various improvements in Microscopes originated by Dr. Goring, that
which he conceives to be the most important is the construction of single
magnifiers from adamant. The details relative to this novel class of
instruments, I have been induced to lay before the public. Single microscopes
naturally aplanatic, or at least sufficiently so for practical purposes, possess
an incontestable superiority over all others, and must be recognised by the
scientific as verging towards the ultimatum of improvement in magnifying
glasses. The advantages obtained by the most improved compound
engiscopes over single microscopes resolve themselves into the attainment of
vision without aberration with considerable angles of aperture; but against
this must be set the never-to-be-forgotten fact, that they only show us a
picture of an object instead of nature itself; now a Diamond Lens shows us
our real object without any sensible aberration like that produced by glass
lenses; and we are entitled, I think, to expect new discoveries in miscrosopic
science, even at this late period, from very deep single lenses of adamant3. I
shall not fatigue my [p016] readers by describing the difficulties which were
encountered in the prosecution of the design of making diamond lenses.
Nature does not seem to permit us to produce any thing of surpassing
excellence without proportional effort, and I shall simply say, that in its
infancy the project of grinding and polishing the refractory substance of
Adamant was far more hopeless than that of making achromatic glass lenses
of 0.2 of an inch focus. I conceive it just to state that Messrs. Rundell and
Bridge, of Ludgate-hill, had, at the time of the commencement of my labours,
many Dutch diamond cutters at work, and that the foreman, Mr. Levi, with all
his men, assured me, that it was impossible to work diamonds into spherical
curves; the same opinion was also expressed by several others who were
considered of standard authority in such matters.

Notwithstanding this discouragement, in the summer of the year 1824, I
was instigated by Dr. Goring (at his expense) to undertake the task of
working a diamond lens: (being then under the tuition of Mr. C. Varley, who
was however at that time absent.) For this purpose, Dr. G. forwarded to me a
brilliant diamond, which, contrary to the expectation of many, was at length
ground into a spherical [p017] figure, and examined by Mr. Levi, who
expressed great astonishment at it, and added that he was not acquainted with
any means by which that figure could have been effected: unfortunately this
stone was irrecoverably lost. Mr. Varley having returned from the country,
becoming now thoroughly heated with the project, permitted me to complete
another diamond, which had been presented to me by Dr. G.: this is a plano-
1
convex of about the 20 th of an inch focus: it was not thought advisable to
polish it more than sufficed to enable us to see objects through it, because
several flaws, before invisible, made their appearance in the process of
polishing. In spite of all its imperfections, it plainly convinced us of the
superiority which a perfect diamond lens would possess by its style of
performance, both as a single magnifier and as the object lens of a compound
microscope. After the completion of my articles with Mr. V., being entirely
under my own command, I devoted some time to the formation of a perfect
diamond lens, and have at length succeeded in completing a double convex of
1 1
equal radii of about 25 th of an inch focus, bearing an aperture of 30 th of an
inch with distinctness on opaque objects, and its entire diameter on
transparent ones; it was finished at the conclusion of last year. The date of its
final completion has by many been considered a remarkable epoch in the
history of the microscope, being the first perfect one ever made or thought of
in any part of the world4. I think it sufficient to say of this adamantine lens
that it gives vision with a trifling chromatic aberration, but in other respects
exceedingly like that of Dr. G.’s Amician reflector, but without its darkness:
for it is quite evident that its light must be superior to that of any compound
microscope whatever, acting with the same power and the same angle of
aperture. The advantage of seeing an object without aberration by [p018] the
interposition of but a single magnifier, instead of looking at a picture of it

(however perfect) with an eye-glass, must surely be duly appreciated by
every person endowed with ordinary reason. It requires little knowledge of
optics to be convinced that the simple unadulterated view of an object must
enable us to look farther into its real texture, than we can see by any artificial
arrangement whatever; it is like seeing an action performed instead of a
scenic representation of it, or being informed of its occurrence by the most
indisputable and accurate testimony.
Previous to grinding a diamond into a spherical figure, it is absolutely
necessary that it should be ground flat, and parallel on both sides (if not a
Laske or plate diamond), so that we may be enabled to see through it, and try
it as opticians try a piece of flint glass: without this preparatory step, it will be
extremely dangerous to commence the process of grinding, for many
diamonds give a double, or even a species of triple refraction, forming two or
three images of an object; this polarization of the light, arising from the
primitive form of the crystal, of course totally unfits them for making lenses5.
I need not observe, that it must be chosen of the finest water, and free from all
visible flaws when examined by a deep magnifier. It was extremely fortunate
for diamond lenses that the first made was free from the defect of double
vision, otherwise diamonds en masse might at once have been abandoned as
unfit for optical purposes. The cause why some stones give single vision, and
others several peculiar refractions, may also arise from different degrees of
density or hardness occurring in the same stone. Diamond-cutters are in the
habit of designating stones male and female, sometimes a he and she (as they
have it) are united in the same gem,—their he means merely a hard stone, and
their she a soft one. When a diamond which will give several refractions is
ground into a spherical figure and partially polished, it is seen by the
microscope to exhibit a [p019] peculiar appearance of an aggregation of minute
shivery cristallized flaws, sometimes radiated and sometimes in one
direction, which can never be polished out: I believe I could disstinguish with
certainty a bad lens from a good one by this phenomenon without looking
through it6. Precious stones, from their crystalized texture, are liable to the
same defects for optical purposes as diamonds.

Having ascertained the goodness of a stone it must next be prepared for
grinding; it will in many cases be advisable to make diamond lenses plano-
convex, both because this figure gives a very low aberration, and because it
saves the trouble of grinding one side of the stone. It must never be forgotten,
that it may be possible to neutralize the naturally low spherical aberration of a
diamond lens by giving it an improper figure, or by the injudicious position
of its sides in relation to the radiant. When the lens is to be plano-convex,
cause the flat side to be polished as truly plane as possible, without ribs or
scratches; for this purpose the diamond should be so set as to possess the
capability of being turned round, that the proper direction with respect to the
laminæ may be obtained: when the flat side is completed, let the other side be
worked against another diamond, so as to be brought into a spherical figure
by the abrasion of its surface. When this is accomplished, a concave tool of
cast iron must be formed of the required curve in a lathe, having a small
2
mandril of about 10 ths of an inch in diameter, and a velocity of about 60
revolutions per second! The diamond must now be fixed by a strong hard
cement (made of equal parts of the best shell lac and pumice-stone powder,
carefully melted together without burning) to a short handle, and held by the
fingers against the concave tool while revolving. This tool must be paved by
diamond powder, hammered into it by an hardened steel convex punch: when
the lens is uniformly ground all over, very fine sifted diamond-dust carefully
washed in oil must be applied to another iron concave tool (I may here
remark, that of all the metals which I have used for this purpose soft cast iron
is decidedly to be preferred): this tool must [p020] be supplied with the finest
washed powder till the lens is completely polished. During the process of
grinding, the stone should be examined by a magnifying lens, to ascertain
whether the figure is truly spherical; for it sometimes will occur that the
edges are ground quicker than the centre, and hence it will assume the form
of a colloid, and thus be rendered unfit for microscopic purposes.
The spherical aberration of a diamond lens is extremely small, and when
compared with that of a glass lens the difference is rendered strikingly
apparent. This diminution of error in the diamond arises from the enormous
refractive power possessed by this brilliant substance, and the consequent

increase of amplification, with very shallow curves. The longitudinal
aberration of a plano-convex diamond lens is only 0.955; while that of a glass
one of the same figure is 1.166; both numbers being enumerated in terms of
their thickness, and their convex surfaces exposed to parallel rays. But the
indistinctness produced by lenses, arises chiefly from every mathematical
point on the surface of an object being spread out into a small circle; these
circles, intermixing with each other, occasion a confused view of the object.
Now this error must necessarily be in the ratio of the areas of these small
circles, which being respectively as the squares of their diameters, the lateral
error produced by a diamond lens will be 0.912; while that of a glass lens of
like curvature is 2.775; but the magnifying power of the diamond lens will be
to that of the glass as 8 to 3, their curves being similar; (or, in other words,
the superficial amplification of an object; with the perfect diamond lens
before mentioned, is 22500 times, while a similar magnifier, made of glass,
amplifies only 3136 times, reckoning 6 inches as the standard of distinct
vision:) thus the diamond will enable us to gain more power than it is
possible to procure by lenses of glass, for the focal distance of the smallest
1
glass lens which can be well made is about the 80 th of an inch, while that of a
1
diamond, worked in the same tools, would be only the 200 of an inch.
If we wish to compare the aberrations of the two lenses when of equal
power, the curvature of the glass must be increased; and as it is well known
the lateral aberration increases inversely as the square of the radius, (the
aperture and position remaining [p021] the same,) the aberration of the
1
diamond lens will only be about 20 th of that produced by the glass one, even
when their thickness is the same; but as the curvature of the diamond is less,
the thickness may be greatly diminished.
The chromatic dispersion of the adamant being nearly as low as that of
water, its effects in small lenses can barely be appreciated by the eye, even in
the examination of that valuable class of test objects, which require enormous
angles of aperture to be rendered visible, which it is evident must be of easier
attainment by diamond magnifiers than by any other sort of microscope.

A mathematical investigation of the spherical aberration of the diamond
when formed into lenses, I hope to lay before the public at a future
opportunity. The comparative numbers here taken from the longitudinal
aberration are, I believe, sufficiently accurate for practical purposes.
18, Picket-Street, Strand.

3 It seems generally admitted that, within a certain range of power not exceeding that of a lens
1
of 20 th of an inch focus, the beauty and truth of the vision given by the new compound microscopes
cannot be equalled by that of any single instrument, at least of glass. It is no less true, however, that
the picture of the compounds, however perfect, is not like a real object, will not admit of
amplification beyond a certain point with advantage. Under the action of very deep eye-glasses, the
image of opaque objects especially, first loses its strong, well-determined outline—then grows soft
and nebulous, and finally melts away in shadowy confusion. Let the experiment be made of raising
1
the power of a compound up to that of a 60 inch lens—then try it against the single microscope of
that power (having, of course, the utmost opening the nature of the object viewed will permit). The
observer, if open to conviction, will soon be taught the superior efficacy of the latter—for it will
show the lines on the dust of Menelaus with such force and vivacity, that they will always be
apparent without any particular management of the light—nor can their image be extinguished by
causing the illumination to be directed truly through the axis of the lens (as it always may in the
compounds). A due consideration of the teeth and inequalities on the surface of a human hair,
together with the transverse connecting fibres between the lines on the scales of the curculio
imperialis, viewed as opaque objects, will suffice to complete the illustration of the subject; though
the last object is not to be well seen by that kind of light which is given by silver cups—and a
1
single lens of 60 inch focus can of course have no other. The effectiveness and penetrating faculties
of simple magnifiers are invariably increased by an accession of power however great—that of
compounds seems to be deteriorated beyond certain limits. An opinion may be hazarded that the
achromatics and reflectors yet made do not really surpass the efficacy of equivalent single lenses,
1 1 1
even of glass, when their power exceeds that of a 20 lens, from 20 to 40 the vision may be about
1
equal—but from 40 upwards infinitely inferior.
The superior light of the single refraction can need no comment—and it is evident that there must
be a degree of power at which that of the compounds will become too dim and feeble for vision,—
while that of the single instrument will still retain a due intensity. For these reasons it is conceived
1
that the close and penetrating scrutiny of lenses of diamond of perhaps only the 200 inch focus, and
an equal aperture (which their very low aberration would easily admit of,) must enable us to see
1
further into the arcana of nature than we have yet been empowered to do. Glass globules of 200 inch
focus and indeed much deeper have been executed; but the testimony of lenses of diamond would
certainly be far more respectable, and is at least worthy of trial and examination.—C.R.G.
4 In Dr. Brewster’s treatise on new Philosophical instruments, Book 5, chap. 2, Page 403—
Account of a new compound Microscope for objects of Natural History—is the following passage:
“We cannot therefore expect any essential improvement in the single microscope, unless from the
discovery of some transparent substance, which like the diamond combines a high refractive with a

low dispersive power.” From which it seems certain that the Doctor never contemplated the
possibility of working upon the substance of the diamond, though he must have been aware of its
valuable properties.
5 There are fourteen different crystalline forms of the diamond, and of this number, from the
laws which govern the polarization of light, the octohedron and truncated cube are probably the
only ones that will give single vision. It is unfortunately very difficult to procure rough diamonds in
this country, so we are compelled to use stones already cut, and to subject them to trial in the way
mentioned in the text.
6 As many amateurs of science might take an interest in the inspection of the peculiar effect
these lenses have on transmitted light, I shall be happy to exhibit them, as also the perfect lens.

Analysis of a newly-discovered Spring, at Stanley, near Wakefield.—By Mr.
William West. ◊

M INERAL springs, dependent for their characteristic properties on carbonate
of soda, appear to have been little noticed by chemists, and to have been still
less attended to as curative means; at least in proportion to the multitude of
cases in which that substance is administered in various other forms. Indeed
the inference to be drawn from the silence respecting the modes of analysis
adapted to such waters in our best elementary treatises, is that they have
hitherto been very seldom met with. In one district, however, of Yorkshire,
carbonate of soda is of frequent occurrence; it is found in the ordinary
springs; often, at the same time with substances with which, in artificial
solutions, or when concentrated, it, would be considered wholly
incompatible; while at other times it is the predominant, or the only
remarkable saline constituent. An analysis of a water of this kind, known by
the name of the Holbeck Spa, has lately been published in the Annals of
Philosophy, by my friend E. S. George; similar springs are found, I
understand, as far [p022] westward as Bradford; they are numerous from the
borings in and near Holbeck; while eight miles south, a water similar in its
character, but differing in containing about twice as much alkali in the same
measure, has been discovered at Stanley.
About two miles from Wakefield, near the Aberford or York road, is an
ancient mansion called Hatfield Hall; near the park or inclosure of which, in

boring for coal, the spring in question suddenly gushed up, when the
workmen had got to the depth of eighty yards, and has continued to run
spontaneously, in all seasons, at the rate of six gallons per minute.
The water at the spring is limpid and very sparkling; the portion which is
allowed to escape, deposits upon the trough and in the channel through which
it runs a quantity of sulphur; the smell is that of sulphuretted hydrogen; the
taste, from the stimulus of the bubbles of gas modifying the softness of the
alkali, rather pleasant than otherwise.
The appearances presented by re-agents are,—
With tincture of soap, a slight opalescence.
Nitrate of silver, an abundant precipitate, partially re-dissolved by pure
nitric acid.
Sulphate of silver, a precipitate only partially soluble in nitric or acetic
acid.
Muriate of barytes, a slight precipitate.
Lime-water, a precipitate soluble with effervescence in acetic acid.
Oxalate of ammonia, no precipitate.
On boiling, a slight pellicle appeared, soluble in nitric acid.
Carbonate of ammonia, no precipitate, nor any on the subsequent addition
of phosphate of soda.
The water restored the colour of litmus paper slightly reddened.
With tincture of galls and ferrocyanate of potash, no change.
With muriate of lime, the water remained unchanged until heated; but
when boiled, a copious precipitate took place.
When concentrated by boiling, the water reddened turmeric paper, and
effervesced strongly on the addition of an acid.
Nitromuriate of platina produced no precipitate, however concentrated the
water might be. [p023]
The results of the previous experiments indicate the presence of
Soda, Lime in small proportion,
Muriatic acid, No magnesia,

Sulphuric acid, No iron,
Carbonic acid, No potash.
A. To ascertain the proportion of sulphuric acid, sixteen ounces by
measure, previously saturated by acetic acid, were treated with muriate of
barytes; the precipitate, washed and dried, weighed one grain; this indicates,
in the imperial gallon, 3.2 grains of sulphuric acid, equivalent to 5.8 sulphate
of soda, dry, or 13 grains crystallized.
B. For the muriatic acid; nitrate of silver, added to sixteen ounces of the
water boiled, and the alkali previously saturated, gave a precipitate weighing
2.8 grains; reduced to the proportion in the imperial gallon, this amounts to
26.9 grains chloride of silver, equivalent to 11 grains chloride of sodium
(muriate of soda.)
C. The crystalline pellicle separated from a pint of sixteen ounces, on
boiling, weighed 0.2 grains.
This was carbonate of lime; but in the water the lime would be combined
with muriatic acid, forming 0.22; or, in the imperial gallon, 2.1 dry chloride,
or 3.75 crystallized muriate of lime.
D. The precipitate formed on boiling with muriate of lime, weighed from
the pint, 3.6 grains; from the imperial gallon, 34.6 grains; showing the water
to contain in that quantity a carbonated alkali equivalent to 53 grains of dry,
or 59.5 crystallized bi-carbonate of soda.
E. Muriate of barytes, added to the water left on evaporating sixteen
ounces to two, gave a precipitate weighing 8.2 grains; deducting one grain for
sulphate of barytes, as found in experiment A, we have 7.2 carbonate of
barytes; this indicates in the gallon 53 grains of dry, and 59.5 of crystallized
carbonate of soda, as in the last experiment.
Lastly, a pint of sixteen ounces of the water, evaporated to dryness,
furnished in three trials of saline residuum, weighed after short exposure to a
dull red heat, six grains, or 57.6 from [p024] the imperial gallon. Now we have
seen that this would consist of

5.8 Dry sulphate of soda (exp. A).
11. Chloride of sodium ( —— B).
1.9 Carbonate of lime ( —— C).
18.7
38.9
57.6

The remainder, 38.9, having been converted by the heat into proto-
carbonate of soda, is equivalent to 54.5 dry, 61 grains crystallized bi-
carbonate, agreeing nearly with the quantities found from experiments D and
E.
Following, as I do, that doctrine which supposes the bases to be distributed
among the acids in a mineral water in the combinations which possess the
greatest solubility, we must suppose the lime to be in the state of muriate; we
shall then have to diminish the muriate, and increase the carbonate of soda: so
that on this view, the saline constituents of an imperial gallon, in the state in
which they exist in the water, are,—
Soda in combination with carbonic acid, equivalent to
Bi-carbonate or super-carbonate of soda 56 gr. dry. 62.5 crystallized
Sulphate of soda 5.8 ditto 13 ditto
Muriate of soda (chloride of sodium) 8.75 ditto 8.75 ditto
Muriate of lime 2.1 ditto 3.75 ditto
The gaseous contents of the water consist of variable proportions of
carbonic acid, sulphuretted hydrogen, and carburetted hydrogen; the latter gas
is continually emitted from the spring, in greater quantity than the water can
absorb; and a portion of the other two also escapes from its surface. I have
made many experiments on the gas, separated by boiling; but find the results,
as I might anticipate, altogether inconclusive and uncertain. In waters
containing, as at Harrogate, these gases with muriates or sulphates, boiling
may be expected almost wholly to disengage them; but in this case the
affinity of the soda in dilute solution, is likely to retain the carbonic [p025]
acid, and even to cause a decomposition of the sulphuretted hydrogen, so as

to prevent our obtaining, in a gaseous form, the quantity really existing in the
water, and imparting to it sensible or medicinal properties.
On the subject of medicinal qualities I am at all times cautious of giving an
opinion: but I may observe, first, that as this spring is dissimilar to any of
those which have already attained celebrity, so none of them can form a
substitute for this; it is not Harrogate, or Cheltenham, or Buxton, or
Tunbridge water: the alkaline springs of the West Riding, of which this is by
far the strongest, stand as medicinal waters hitherto alone; the active
ingredient, the bi-carbonate of soda, being spoken of in chemical works, as
“rarely found in mineral waters.”
Secondly, from the known properties of this substance, carbonate of soda,
and the frequency of its administration in a long train of arthritic, calculous
and dyspeptic complaints, the water must be highly useful as an anti-acid and
as a diuretic; and as the advantages which native mineral waters possess over
artificial solutions of the substances, in the great degree of dilution, and the
impregnation with gases, and still more in the adjuncts of leisure, exercise,
pure air, regulated diet and early rising, are of especial consequence in the
latter very numerous class of diseases, those called stomach and nervous
complaints; we may fairly suppose that such a spring will be found to be a
valuable addition to those previously known, applying, as it does, to cases of
such frequent occurrence.

Observations on the State of Naval Construction in this Country. ◊

I T appears that there is at present a tendency to improvement in every branch
of science; monopoly in intellect may now be said to be vanishing; and
empiricism is obliged to seek dark corners, to escape the light which is
penetrating into regions from which it had but very lately been excluded. The
administration, too, encourages advance of knowledge; yet notwithstanding
these favourable circumstances, there still exists, in [p026] some minds, an
inaptitude of scientific perception, which induces unwillingness to

acknowledge the advantage that results from the application of the exact
sciences to the useful arts.
This neglect of scientific principles is nowhere more manifest than in the
affairs of naval architecture, and it is not confined to the Royal Navy, but
extends also to our mercantile shipping; and hence it is that our commercial
marine is in some respects behind foreign nations, especially the Americans,
in the formation of its ships: our merchantmen are, almost without exception,
the most unsafe7 and slowest ships in the world. The ship-owners, therefore,
would do well to consider this circumstance, and endeavour to devise means
of introducing science into the merchant yards. The establishment of the new
university in the metropolis affords an opportunity of doing it at a
comparatively small expense, by the foundation of Lectures on the theory of
Naval Architecture; and the support even of a separate institution in the
vicinity of the merchant yards of this great port, for the education of ship
surveyors, would soon be repaid by the improved character of our merchant
shipping.
If the science of Naval Architecture depend on certain physico-
mathematical laws, as no doubt it does, it is monstrous to imagine for a
moment that such laws can be developed by a flight of fancy, or that a man is
born with an intuitive optical perception of the lines of least resistance, &c.,
or, in the jargon of the craniologists, that he has a naval-architectural bump
on his skull; yet one would think that such was the case, when we see men,
we cannot say philosophers, start up and loudly assert that they are in
possession of the secret of construction; and they are believed because their
hypotheses are never submitted to the examination of those who are capable
of detecting their fallacy.
The Experimental Squadrons have, with a multitude of perplexing results,
elicited, it must be confessed, at least an interesting fact, viz. that there has
been an establishment seventeen years in this country, in Portsmouth
dockyard, for the scientific education of naval architects, for the Royal [p027]
Navy.8 From the plan of education, as laid down by the Commissioners of
Naval Revision in 1810, it appears that, to a requisite knowledge of the

practice of their profession, the gentlemen composing this body of naval
constructors unite a sound and competent one of its theory9.
It can only be from such a source that we can look for the improvement of
our men of war, and it is to be regretted that every means should not be taken
to avail ourselves of it: but unhappily such is the force of prejudice that,
unless some alteration should be adopted in this institution, it will be in vain
to expect advantage from it.
The objection urged against this establishment, namely, that the scientific
education it gives to its members precludes them from the attainment of a due
knowledge of the practical construction of our ships, is so absurd, that none
but weak or jealous minds could ever have brought it forward. Shall it be laid
down, in the present age, as an axiom, that a profound ignorance of the
principles of his art is the one thing essential to the formation of what is
generally meant by the term “practical man?” We contend that, having made,
in vain,10 a long and most indulgent trial of a system without science, if we
may use such an expression, we must extend to one in alliance with it, a like
patronage, before we can be allowed to pronounce a fair and legitimate
judgment upon its efficiency.
But even in the peculiar path in which the naval architects educated at
Portsmouth might be supposed to excel, we do not find that any opportunity
is allowed them to come forward, nor shall we see this until some effort is
made by the heads of our naval departments, to allow a broad and open
competition to take place. It may be urged, that the learned Professor at
Portsmouth (Dr. Inman) in himself includes all that can have [p028] possibly
been taught or understood in the establishment over which he presides, and
that therefore he is the representative of it in the late and present trials for the
palm of excellence; but we cannot by any means assent to this: many of the
students must have left his tuition seven, eight, and nine years, and must be
between thirty and forty years of age; and it would be strange indeed, if
during such a period, and in the prime of life and intellect, some of these, if
not all, had not cultivated the science after their own bent of mind, and
formed original ideas on the subject: we say, therefore, that Dr. Inman’s
constructions cannot be called the production of the establishment—they are

merely the effort of one man, whose attention it appears is distracted by a
multiplicity of occupations, and can only, along with the vessels of Capts.
Symonds, Hayes, and Sir R. Seppings, be deemed criterions of the particular
views of an individual.
Mysticism and ignorance always accompany each other; and we may
reckon that in proportion as the latter disappears from amongst our ship-
builders, so will the absurd vagaries of the former recede, and the subject be
placed at last on the true principles of philosophical induction, instead of the
caprices of imagination. We look forward, therefore, to this new body of
naval architects for the expulsion of all quackery from their profession, and
for the exposition not only of what we really do know, but also of what we do
not know about it: this is the only way to arrive at truth, which should be the
sole object of all investigation; but which we are afraid has hitherto been
sadly garbled and perverted wherever it has had to do with naval architecture
in this country.
But we repeat that we do not see that the nation is at all likely to benefit
from the science or exertions of those gentlemen so long as they are placed in
situations where a superior education can have no other effect than producing
disgust and chagrin in the mind of the possessor; and if the institution at
Portsmouth be designed for no better purpose than that of supplying house-
carpenters, joiners, and still more inferior trades, with foremen, it had better
be abolished. Some would regard it, as at present used, as a gross mockery on
the public [p029] at whose expense it is supported; it is certainly a cruel one of
those who have been induced, by the fair and brilliant prospects held out to
them of support and encouragement, to devote their lives to this branch of the
public service.
But to return to the Experimental Squadron: it is with regret that we must
conclude, upon a careful consideration, that, although the experiments are
carried on with so much vigour and interest, they are evidently founded on
imaginative views, and that there cannot exist any thing like legitimate data
where so many failures and anomalous results obtain. Who can read the
account of the first Experimental Squadron11, without immediately perceiving
that the constructors of the contending vessels, however sanguine each might

have been of the success of his particular fancy, met with nothing but the
most perplexing results? We see sometimes one and sometimes the other
vessel claim the palm of excellence, and finally leaving the subject as much
in the dark as ever. This is the natural consequence of the non-application of
inductive philosophy to the question before us, and the most important
conclusion that can be gathered from the experiment is, that we have begun at
the wrong end, and that it is high time to employ analysis instead of synthesis
to effect the desired objects: for in the present state of the theory of naval
construction in this country, there are yet no data existing to effect with
precision and confidence the synthetical composition of a ship.
We cannot refrain here from noticing the paucity of information contained
in the reports hitherto made on the first Experimental Squadron. The best
one11 is but little removed from a ship’s log book, and in some respects is
inferior to it: it is of such a scanty nature, that we can scarcely inform
ourselves on any point, and that only in a relative degree, of the qualities of
the vessels composing it: we cannot find out any mention of their absolute
velocities on the different points of sailing, which is a most important
omission. We are neither informed in what way the observations were
conducted, whether they were made simultaneously or not: unless the former,
any attempt at comparison must be very doubtful, if not entirely fallacious.
Circumstances of wind and the weather may very widely alter in the [p030]
course of a short time, and every endeavour at legitimate analogy be
destroyed by such variation. We strongly suspect that this is one cause of
perplexity; and another prolific one is the vague idea given of the strength of
winds by nautical language. Nothing but the determinations of the
anemometer should ever be allowed to appear in an account of such
experiments. Every circumstance attendant on the quantity and trim of sail,
the heeling, the rolling and pitching of the ship, position of the rudder, &c.
should be accurately ascertained and tabulated; for it is next to an
impossibility and a wilful waste of time to attempt to institute comparisons
without pursuing a system of tabulated results, which should be kept in the
same form on board each ship.

We must also express our regret that the scientific professor at Portsmouth
does not appear to have ascertained the position of the centre of gravity of
any of his ships, with regard to height, by the simple and easy experiment
long known in principle, and described lately with geometrical rigidity in two
or three publications by some of his pupils12. The knowledge of the position
of this point would have placed him so far above his competitors, in so many
important particulars, that we are surprised he should have thrown away his
advantage, and descended to a level with his less scientific opponents. We are
afraid that, here again, imaginative views have stepped in, and taken the
sober mathematician from the only path by which excellence can be attained.
We are at a loss to conceive how the stabilities of his ships can be said to be
ascertained without the knowledge of the position of this point.
Some of the obscurity which pervades this difficult subject may be
overcome, as to broad and general principles, by attentively and coolly
observing the progress of marine architecture, since the introduction of
cannon into naval warfare, and more particularly during the last century and a
half. We shall then clearly perceive that the French, who, as early as the
beginning of the reign of Louis XIV., employed men of first-rate talent in
their naval arsenals, and neglected no opportunity for the [p031] advancement
of science in them, increased and kept increasing the dimensions of their
ships, more especially the length, the ratio of which to the breadth has been
augmented by them from about 3 14 .1, to 4.1 within the last century. While this
principle was acted on, the improvement of their ships was gradual; and by
referring to our own progress in the art, in tardy imitation of the practice of
the French, we shall likewise conclude that our navy has derived precisely
similar advantages from the same causes. Here we have at once two grand but
concurring results derived from an experiment, not made on one or half a
dozen different vessels, but on the whole navies of the two most powerful
maritime states in the world: and if to these we choose to add the result of the
practice of the same means on the Spanish and other navies, we might surely
be warranted in saying, from this broad but certain analysis of facts, that, in
relation to the hull, the general increase of dimensions, with a greater relative
length, is one cause of the improvements that have been made in the sea-

going qualities of the ships composing the fleets of the present maritime
powers: the question therefore that remains to be decided on in relation to this
principle is, whether we have arrived at its utmost practicable limits, or
rather, whether we have arrived at the maximum of improvement it is capable
of producing.
This brings us again to the experimental squadrons, as far as they are
connected with, and illustrative of, our observations; and the first question
naturally put forward about them is, whether there be any thing very peculiar
in the formation or dimensions of the rival vessels? We suspect that the
answer cannot otherwise than disclose, that neither in principle, dimensions,
nor in the formation, can they be said to differ very materially from each
other, or from ships of the common construction: indeed we perceive in some
a retrogression of ideas and a violation of the principle, that the increase of
the ratio of the length to the breadth, in conjunction with a general increase of
dimensions, has been a predominant cause of improvement. The fact also of
so immaterial a difference necessarily includes a system of masting and sails
equally confined, and totally inadequate to produce any great superiority of
sailing over ships to which they are so nearly equal in principal dimensions.
[p032]
After so many years of trial with the present nearly invariable set of
principal dimensions, during which period it may be said, that every possible
contour of hull has been experimented on with them, we are inclined to think
that almost all has been done that could be done under such restrictions, and
that some great step must be made in one or other of the principal dimensions
themselves, with correspondent alterations in the masting, before we can
expect to see a decided and great improvement in the sailing of our ships. The
depth is an element which has arrived at its limit from very apparent external
causes; but the length and breadth remain to the skilful constructor without
any such clogs to his endeavours; and he has only to accommodate their
relation to each other in the manner most conducive to velocity, which in our
opinion is the very capital object of naval construction, both in ships of war
and of commerce. That it is so in the former, no one will, we apprehend, on
due reflection deny; but there will be many who will assert that it cannot be

obtained, in the latter, without a sacrifice of capacity; which will defeat the
object of carrying large cargoes: to this we may reply, that if a vessel with an
expense of one quarter the capacity can make three voyages instead of two,
will not the merchant be still a considerable gainer in capacity, and still more
so by a ready return of his capital13?
All observations on well-conducted experiments concur in proving that
velocity is gained by increasing the length, to a much greater degree in
relation to the breadth, than has ever yet been done in ships; and that the
increase of the same element contributes to their weathering powers is too
obvious to need insisting upon: it is also generally advantageous, when not
carried to an extent which would seriously retard the manœuvring of the ship.
This limit has not yet by any means been determined; for it must be
recollected, that although the additional length increases the resistance to
rotation about a vertical axis, yet the power of the sails to give rotation about
the same is also increased, although not in so high a ratio. The power of the
rudder to produce rotation is also greater in a long ship than in [p033] a short
one, not only on account of the greater distance it is from the axis of rotation,
but also on account of the greater velocity, and the more direct impulse of the
water on it.
The increase of the ratio of the length to the breadth to produce velocity
should not interfere with the increase of breadth necessary to produce
stability or capacity; for both these qualities, varying as higher powers of the
breadth, a very small increase of breadth may be attended with a considerable
increase of length. If we compare the Caledonia’s (120 guns) dimensions with
those of the Royal George and Queen Charlotte14, of 1788 and 1789, we shall
find, that 13 or 14 times as much length as breadth has been added to the first
rates of our navy. If we refer to the dimensions of the Commerce de
Marseilles, and those of the next preceding three-decker of the French navy
(for instance, the Ville de Paris15, taken in Lord Rodney’s action), we shall
find that the French naval architects gave in her 21 times as much increase to
the length as to the breadth. If this could be done with safety in a three-
decked ship, with such a vast top weight, much more could it be carried
advantageously into effect in ships of two decks, and frigates; but we do not

find, in the latter classes of the ships of the French navy, the increase of
length to go beyond six times that of the breadth. If we refer to the Old
Bellerophon, built in 1772, and the New Bellerophon, built in 1819, we shall
find an increase of 24 feet in length, to 1.58 feet increase of breadth; or the
former more than 15 times the latter16.
To those who oppose the objection that a greater length than at present
used would make the manœuvring of a ship too slow, we answer, that as the
Caledonia and the present first rates of our navy, although from 10 to 15 feet
longer than our two-deckers, are found to be capital ships in this respect,
there is a sure ground to believe, that the addition of 20 feet in length to the
present two-deckers would not render their celerity [p034] of evolution less
than that of the three-decker; and since, from the reduction of weight aloft,
the centre of gravity would be lowered, and the displacement required to be
less, a somewhat smaller breadth might be allowed to a two-decked ship of
206 feet long, than to one of 196 feet (especially since the quantity of sail,
remaining the same, is lowered by one whole depth between deck), a smaller
midship section would be, cæteris paribus, required; the velocity of this ship
might be considerably increased. Nothing however can be precisely
determined on, with such a complication of circumstances, beyond a general
idea. Calculation and a strict analysis of ships must be resorted to, in order to
fill up the outline of our reasoning.
But for the same reason that we imagine that an addition of 20 or perhaps
40 feet would not sensibly injure the celerity of manœuvring of our two-
deckers, we should think that the same increase of this dimension might be
tried without much risk to our first rates, with an increase of breadth not
1
exceeding 20 part that is given to the length.
We repeat that the very capital object of the science of Naval Construction
is velocity, and we are decidedly of opinion that it is attainable in a much
higher degree than at present, without compromising other necessary
qualities, for which we have the concurrence of facts as far as they go.
The Anglo-Americans, in the last war, took every possible advantage
suggested by views similar to those we have been adverting to, in the
construction of their large frigates. They had, it may be said, to create a

martial navy, and they had to oppose it against fearful odds; but, free from the
prejudices and errors so blindly cherished by their opponents, and which
constantly oppose reform by always declaring the present practice to be the
best, they did not retread the old path, but began at its last step, and boldly
advanced on this principle into all the branches of the art. They built vessels
upon the most enlarged dimensions, and of a superior weight of metal, and
gave an increased ratio of length to the breadth. The result of such a
procedure, justified the confidence of the American naval architects in only
one maxim, founded upon the scientific observation of facts, and may give us
a faint idea of what might be effected by a still more enlarged and
mathematical analysis. [p035] Our frigates were so inferior to theirs in every
way, that they brought nothing but disasters upon us, excepting in the action
between the Shannon and Chesapeake, and one or two others, where, assured
by their previous successes, our gallant opponents threw away the advantages
possessed by their ships, by coming to close quarters at once, and deciding
the contest hand to hand.—Our ships of the line could never bring these
frigates to action, and owing alone to their extraordinary sailing, did they
evade and mock a large British fleet. We were finally obliged to build 60-gun
frigates after their method, but when it was too late for the exigency of the
period; and thus it has ever been our fate, for want of science in the
constructors of our navy, to follow the steps of our enemies at a humble
distance, and to be only then driven out of the old track by a terrible
experience of its inefficiency.
Nor have the Americans stopped here;—Mr. Huskisson plainly tells us that
“America is, year after year, augmenting its military marine, by building
ships of war of the largest class17.” According to Capt. Brenton, they have
built a first-rate18 of 245 feet length on the gun deck, and 56 feet broad19, to
carry 42-pounders on the lower deck, and 32-pounders on the other decks.
Our small class of 74-gun ships lately converted into frigates carrying fifty
32-pounder guns, we are fearful can only produce disappointment if ever
brought against the American frigates (not by conversion, but by
construction), which carry sixty-two guns of the same calibre, and are 180
feet long on the gun deck.

We must not forget also that our active neighbours the French have now
adopted a most formidable description of [p036] frigates, with curvilinear
sterns20, and many other important improvements. They mount 60 guns and
carronades—viz. 24-pounders on the gun deck, and 36-pounder carronades
on the flush deck.—The former calibre is equivalent very nearly to 26, and
the latter to 39 lbs. avoirdupois.
When we reflect on these circumstances, we cannot but feel surprised that
so many frigates of inferior force and dimensions should be building in our
dockyards. In time of emergency they will only bring on us a repetition of
former disasters and deficiency. We contend that, instead of building ships of
only equal force to those of our rivals, and thus waiting for the developement
of their designs before we can venture on a single step, we should build
beyond them in every respect. It must and ought to be recollected, that peace
in these matters produces a contest of intellect, and those will have the
advantage in it who attack instead of standing on the defensive. We ought to
lead the way, and to be at the head of the maritime world, not in number
alone, but also in the individual force and qualities of our ships.
Having expatiated on the advantages of an increased ratio of length to
breadth in relation to the hull of a ship, we will just glance at some of the
principal effects it would have upon the masting and sails; and here again we
conceive that Professor Inman has, in common with many others,
relinquished the many good effects resulting from it, for the inadequate one,
of being able to carry a somewhat greater quantity of sail, which must
necessarily be lofty, and which, (setting aside this detracting circumstance,)
as the velocity of a ship varies only as a fractional power of the surface of
canvas spread, cannot produce the degree of fast sailing to be wished for, but
at an immense and impracticable quantity of sail21.
A greater proof of the inadequacy of the present system of [p037] lofty sail
cannot be cited than the fact of its not procuring, under the most favourable
circumstances, a rate of sailing rarely exceeding one-fourth the velocity of the
wind.
As the number of masts should be so regulated as to create facility in
managing the canvas, which is well known to be at present hardly

manageable in a gale of wind, on board large ships, from the enormous size
of each individual course and topsail, we should not hesitate, therefore, to
have four vertical masts, as recommended by Bouguer, instead of three, in
ships built in accordance with the principles we have been discussing. This
would, cæteris paribus, require shorter masting and smaller yards, and the
sails being much less, individually, would be more easily managed and not so
liable to accidents.
From what has been said, and the actual experiments now pending, it is
apparent that the theoretic construction of ships is at a very low ebb in this
country; yet a fine opportunity now presents itself, if we choose to avail
ourselves of it, for rescuing the nation from this generally acknowledged
odium. Let a proper use be made of the corps of Naval Architects we have,
somehow or other, at last got, and let their exertions, under a degree of
encouragement equal to that bestowed on the old ship-builders in vain for so
long a period, be directed towards the improvement of their art. If they fail,
they cannot claim the excuse of having their endeavours repressed; if they
succeed, as no doubt they will, in advancing their profession to something
beyond mere carpentry, we shall be enabled to bid adieu to the old and
ruinous method of blundering, under the reign of which nothing but
disappointment can ever be reasonably expected.
We have seen and do still see the immense advantages derived by our
country from the encouragement of those branches of science connected with
its manufactures and agriculture; and if we wish to keep our present
superiority, we must follow up vigorously this principle in all its universality.
To the cavils of ignorance and bigotry against such a mode of proceeding we
would answer, in the words of one of the most enlightened members of the
present administration, “This country cannot stand still, whilst others are
advancing in science, in [p038] industry, in every thing which contributes to
increase the power of empires, and to multiply the means of comfort and
enjoyment to civilized man.”22
It is to be hoped, therefore, that His Royal Highness the Lord High
Admiral will extend to this most important national institution, the School of
Naval Architecture, the same vigilant and scrutinizing eye that every other

branch of our naval system is at this moment experiencing from him, and that
he will extend to it that fair play and encouragement which has hitherto been
denied to it. As a seaman, he can fully appreciate and understand how much
the bad qualities of a ship may neutralize the best exertions of the most
experienced and skilful sailor; and, on the contrary, what a degree of
confidence may be insured in naval operations with excellent ships. We feel
persuaded, therefore, that he will not allow others to think for him in a matter
of so much national importance, and thus allow private ends to interpose to
the disadvantage of public views; but that he will investigate and judge for
himself. We would humbly suggest to His Royal Highness to inquire into the
individual acquirements and productions, both of a theoretical and practical
nature, of those who have been educated in this establishment, and he would
soon be able to decide whether they be fitting or not for the important task of
constructing our ships, and for the confidence and protection which we think
we have shown has hitherto been ill-advisedly withheld from them. Such a
line of conduct would very soon carry our naval architecture to a pitch of
excellence worthy of imitation, and instead of being indebted to foreigners for
models, we should be able, with just pride, to point to the productions of
British science and intellect in this noble art.

7 By referring to Lloyd’s List, it will appear, upon a moderate average, that three English
merchant vessels are lost every two days!
8 See No. II. of the Naval and Military Magazine, published in June last.
9 This will be readily acknowledged by those who will choose to read the “Papers on Naval
Architecture,” and the “Essays and Gleanings on Naval Architecture,” two periodical works
proceeding from the members of this institution.
10 See the Third Report of the Commissioners of Naval Revision, and the Resolutions of the
Society for the Improvement of Naval Architecture, in which the old system of providing ship-
builders for the Royal Navy is condemned in the most unqualified terms.
11 Vide No. 1 of the Papers on Naval Architecture.
12 Vide Annals of Philosophy, for November, 1826; No. 1 of the Papers on Naval Architecture,
and No. 11 of the Essays and Gleanings on Naval Architecture.
13 Foreign nations, and more particularly the Americans, find their advantage in having swift
merchant ships, and therefore our assertion is warranted by facts.
14 Caledonia, length 205 feet, breadth 53.5; Royal George, length 187 feet, breadth 52.33 feet;
Queen Charlotte, length 190 feet, breadth 52.33 feet.

15 Ville de Paris, length 185.62 feet; breadth 52.7 feet; Commerce de Marseilles, length 208.33
feet, breadth 54.79 feet.
16 Old Bellerophon, length 168 feet, breadth 47.33 feet; New Bellerophon, length 192 feet,
breadth 49 feet.
17 Vide this gentleman’s speech on the Shipping Interests in the House of Commons, May
1827.
18 Called by Capt. Brenton the Ohio; but it appears from Lieut. De Roos’ personal narrative,
just published, that the Ohio is a two-decker of 102 guns. It is to be supposed, therefore, that the
three-decker of 135 guns, called the Pennsylvania by the latter, is the ship alluded to by the former.
It is a matter of great regret that Lieut. de Roos has not presented us with the precise dimensions of
these ships.
1
19 These dimensions carry the ratio of the length to breadth above 4 3 to 1.

20 The French Admiral Willaumez, in his “Dictionnaire de Marine,” published in 1820, says
under the article Frégate, that as far back as 1804, he had proposed a plan for a frigate of the largest
size, with a round stern, wherein the quarter galleries were suppressed: the first frigate upon his
plan was built at Brest about 1821.
21 As the square root, so that to get twice the velocity, four times as much canvas must be
spread; and this is the most favourable estimate that can be made.
22 Vide Mr. Huskisson’s speech on the Shipping Interests.

[p039]

On Malaria. No. II. ◊
[Communicated by J. Mac Culloch, M. D., F. R. S., &c. &c.]

H AVING pointed out, in the former paper on this subject, the nature of the
soils or places, of whatever description, by which malaria is generated, it
remains to notice a few other circumstances connected with its natural
history, a knowledge of which is essential for the purposes of prevention; and
finally to describe such modes of prevention, applicable to these several
circumstances, as have been found useful in guarding against the attack of
diseases from this cause. Under the first head, there remain to be considered,
the effects of climate and season; the changes which occur in the production
and propagation of malaria, from various natural and artificial causes; and
also, the various modes in which it is propagated.

It has already been remarked, that a certain elevation of temperature was
necessary to the production of this poison, though what the precise degree is,
has not been ascertained; and as this is, chiefly, what distinguishes the regions
or periods of the year which generate malaria, I need not make two divisions
of season and climate. If, however, this temperature is not fixed, it will
perhaps suffice for our present purposes to say that the greater part of
Scotland, whether as to climate or season, seems incapable of generating the
disease from this cause; though there are exceptions of a permanent nature, or
exceptions of climate, as was perennially true of the Carse of Gowrie before
its drainage; while there are others which happen when, as in the last year,
there has been a peculiarly hot summer, and which are exceptions of season.
And thus it is as to more northern regions; where a hot summer becomes
more than an equivalent for an average low temperature; as an example of
which, there is no place where intermittents are more severe and abundant
than at Stockholm. But the extreme of evil from this cause occurs, as is well
known, in the tropical climates; appearing almost proportioned to the heat of
the climate, and what is important to observe to the moisture also. The
destructive effects of certain parts of Africa, India, America, and so forth, are
familiarly known; and [p040] it is in these countries especially, that the
diseases from this source constitute nearly the entire mortality of the human
race. And thus, for Europe, it is in Spain, Italy, and Greece, and chiefly on
their Mediterranean shores, that the activity of malaria scarcely yields to that
of the intertropical climates; while in France, Holland, Germany, Hungary,
and with us, in a far less degree, the production will be found regulated by the
heat of the summers, all other circumstances being the same.
And if we thus account for the variations in the quantity and virulence of
diseases in any given country, for noted seasons of epidemic in the countries
which I have just named, and for the great prevalence of fevers among
ourselves during the last few years, and particularly in the last summer, there
is another point of scarcely inferior importance to be taken into the
consideration, independently of that which relates to peculiar winds as
connected with the propagation of this poison;—and this is, moisture.

I need not repeat that water in some form is necessary to the production of
that peculiar vegetable decomposition which is the source of this poison; and
so true is this, that even in the tropical regions, the diseases from this cause
are nearly unknown in districts of peculiar dryness, as they are in the drier
seasons of those countries. Thus, for example, Egypt is free from such fevers,
except at the period of the subsidence of the Nile, unless where, as at
Damietta, the cultivation of rice is pursued; and the same is true of
Mesopotamia very remarkably: and if I dare not extend these illustrations, I
must remark that in all these cases, the action of moisture is twofold,
inasmuch as it not only accelerates vegetable decomposition, but renders the
atmosphere a fitter conductor of this poison.
Taking these two causes of the increase in the quantity and in the action of
malaria, we can explain many particulars which relate to its power in
producing diseases: and as the knowledge of these is important as far as
relates to the main object of this paper, prevention, it becomes necessary to
explain them at a little more length.
As to season, the simplest case is that of the intertropical climates; and
Africa offers the plainest instance among the [p041] whole. There, the malaria
and the fever commence at the moment the rain falls; diminishing as the
ground becomes thoroughly wetted, and recommencing as it dries. The
explanation of all this ought to be obvious; and the same analogy governs all
the hotter climates, as, though less conspicuously, it does our own. Hence we
explain, both as to our spring and our autumn, the effects of heat following
rain, or the reverse, and the diseases which are consequent on those changes:
and thus it is, though more remarkably, in Italy, that a rainy autumn increases
the number and severity of fevers; or, if the summer has been unusually dry,
that they often do not appear till the commencement of the autumnal, or even
the winter rains. And hence, also, even with us, the occurrence of a single
rainy day or week, in the midst of the heats, will produce fevers; while the
effect of this influence is such, that should there even be an entire rainy
summer, and the subsequent one be hot and dry, this will be attended by an
unusual production of malaria and disease.

And if I cannot detail all the various modes in which these circumstances
may be modified, and how their effects may vary, it will be useful to make
one remark on an error as relating to it which is universal among us, and into
which even Lind has fallen. The error is, to think that the rain, the moisture,
or the cold is itself the cause of the diseases which follow this state of things;
while it is obviously a case analogous to that of Africa, if less severe, and the
malaria is produced by these circumstances on soils which I formerly pointed
out, and which Lind, like every one else, had neglected. But if I must pass
over many interesting and useful conclusions to be drawn from these general
principles, there is one fact which I must notice, and it is this:—
In spring, the combination of heat and moisture, easily explained,
generates, most commonly, intermittents; or the effect of the malaria at this
season differs from what it does in autumn: while as the heat advances and
the ground dries, this kind of fever ceases to be produced, a new species, or
the summer remittent, taking its place when the heat and the moisture of
autumn begin to act. But under peculiar seasons of heat and moisture with us,
it sometimes occurs, as it has done [p042] within the last years, that the
intermittent season runs into the remittent one, or there is no midsummer
interval of freedom from disease; while it has also happened, and in some
parts of England in this last year, that what would have been intermittent
fever in other years has been remittent; or the common fever has occupied the
whole summer, continuously, even from March to November, as is the case in
the worst regions of southern Europe.
Now, under these exceptions, which I was bound to explain, the
commencement of intermittent, or of vernal ague, may be fixed about the
middle or end of March, and its termination similarly in May; while that of
remittent may be placed in the beginning of August, and its termination with
the middle or end of October. How these periods may otherwise be affected
by the more or less insalubrious nature of the district or place, will easily be
judged of by those who will reflect for themselves on what I dare not explain,
lest I should infringe too far on my limits. All else that I can venture on, as to
this part of the question in hand, relates to the effects of the different times of

the day on the production, propagation, or influence of malaria, and it is one
which is of no small importance in a practical view.
Whether the changes as to temperature and moisture which occur within
the space of twenty-four hours, affect the production or propagation of
malaria, I will not here inquire minutely, from the fear of prolonging this very
limited paper; but the general facts, as to its effects, are these: If we
commence with the sun on the meridian, there appears, even in the worst
climates, very little hazard of fever; while in Italy, it is believed that there is,
generally, little or no hazard, except in some peculiarly pestilential places,
and under particular kinds of inattention or neglect. Either the malaria is
decomposed or destroyed by the heat, or else the air from its dryness ceases
to be a conductor; but as evening approaches, its influence becomes powerful
and dangerous, being supposed most generally to extend all through the
night; while in some parts of that country it is a popular belief that it
terminates before midnight, or with the precipitation of the atmospheric
moisture. Whether this last opinion is true or not, the general fact explains the
popular [p043] belief, and truth, respecting the poisonous effects of dew in the
hot climates; the supposed pernicious quality of this depending evidently on
the malaria by which its formation is accompanied. And in this case it is
probable that the evil arises, not from a fresh or peculiar generation of
malaria, but from the mere fact that the moist atmosphere is a better
conductor than a dry one.
Not to be unnecessarily minute, we thus also explain the danger of
exposure to the morning air in similar situations; the facts, as they relate to
the conducting of malaria, being the same, though the meteorological
circumstances are somewhat different. Hence, also, we see why the grey
mists which hang over wet grounds in the evening in our own climate, are
esteemed pernicious; the truth, however, being, that they are perfectly
innocent at certain seasons and in certain places—as in the greater part of
Scotland, for example, or in those places and at those periods where malaria
is not produced. The distinction is valuable, because of the inconvenience of
restrictions on this subject, and because to know where the hazard really lies
is to reduce those, and also to prevent the infraction of rules by not extending

them beyond what is necessary; and thus also by seeing what are the real
dangers of what is called night air, we more easily avoid them. Night air is
avoided now, under a false philosophy, because it is cold or damp, or for
some other vague reason; while the dangers from mere dampness or cold are
as nothing compared to those here pointed out; which also occur precisely
where they are least feared, namely, in warm summer evenings, after
refreshing showers, and so forth. Hence it is that fevers are produced in
summer, in rural situations, and especially perhaps amid the most engaging
scenery, by evening walks and exposure to what is naturally considered, as it
is felt to be, a balmy and refreshing sequel to a hot day. Let this be enjoyed
where it can with safety, and as it often may; but such evening walks will not
be safe in any of those situations which I need not repeat here; after having
detailed them as I have done in the former paper. And lest I should be accused
of wishing to excite unnecessary alarm, I consider, on the contrary, that it
ought to be diminished by these remarks; because, if we take the whole of
[p044] England, there is perhaps not one acre in a hundred thousand where
there is danger from night air, or from malaria in any mode; so that to
distinguish where that lies, is to have relieved from useless fears all those
who may learn to make the distinctions under review.
To pass from what relates to climate and season, and to proceed to the
propagation, simply, of malaria, it is almost superfluous to say, that its
influence, as to the production of disease, is much regulated by proximity,
which implies a state of concentration or accumulation. Hence the danger
arising from vicinity; while, as I formerly remarked, where the generating
source is small, this becomes necessary to its effect, since dilution may be
expected to destroy the power of the poison.
For analogous reasons, its effect in the production of disease is increased
by concentration or condensation; and such a state of things takes place in
narrow and confined valleys, or in places surrounded by woods, or in woods
themselves; in any situation, in short, where the poison is produced, and is so
sheltered from winds that ventilation becomes difficult. And if it is probable
that this is one chief reason of the peculiarly insalubrious nature of woods
and jungles in hot climates, so is it an universal remark in Italy, that the short

valleys in which the air cannot circulate are among the most pestilential
spots. And if this explains, also, in some measure, the bad effects of calm
weather, so does it account for the unusually pestiferous nature of rivers and
lakes confined within wood, as are those of the tropical climates, and as there
are many also in different parts of Europe. That we ourselves are not exempt
from these additional causes of the influence of malaria, would be easily
shown by many references, were it not for the reason which has caused me to
exclude them.
It is another important question for practice, how far and in what manner
malaria can be conveyed by the winds to places where it is not produced, so
as to act in exciting disease. That it is conveyed to certain distances by winds
is amply proved by an abundant experience, and I may first detail a few of the
most useful particulars as to this fact. In Italy and Greece, it is observed, that
where long valleys terminate on sea shores, on which the exits of the rivers
are swampy, it is an [p045] effect of the sea breeze, by crossing such marshy
ground, to convey the malaria up into the interior country, to considerable
distances, and to places which are in themselves not insalubrious. Thus, also,
does such a breeze, especially when it is a warm wind, convey the poison up
the acclivities of hills, even to a considerable range of distance or elevation; a
process facilitated by the natural tendency of such winds to ascend. And as a
striking proof of this migration of malaria, it appears from Capt. Smyth’s
statistical account of the insalubrious villages in Sicily, that out of more than
seventy, about one-half are not seated near or on lands producing this
substance, but on acclivities, at varying distances—thus receiving it through
migration. The same is remarked by Montfalcon of many towns in France;
while in some, the place at a distance is even more unhealthy than that which
is immediately situated in the marsh itself: and in our own country, this is
equally said to be true of the backwater at Weymouth, and of the marshes of
St. Blasey in Cornwall, acting more powerfully at some distance than in the
immediate spot.
With respect to the absolute distance to which the malaria can be
conveyed, it is yet an obscure circumstance, or at least the maximum has not
been fixed; but it is at least ascertained that the convent of Camaldoli receives

it from the Lake Agnano, at a distance of three miles; while from certain
naval reports, a distance of five miles has been proved to permit its
transmission,—and from an evidence that cannot be doubted, inasmuch as it
was the sudden breaking out of fever in a healthy ship, anchored at that
distance from the shore, on the coming off of the land wind, attended by its
peculiar and well-known smell.
These facts are satisfactory thus far, and it would be abundantly easy to add
to them; but there is reason to suspect that it can be conveyed to far greater
distances, in certain favourable circumstances: those reasons, in the first
place, being derived from certain meteorological analogies and
considerations, and in the next confirmed by experience. It is notorious that
the ague appears on our eastern coasts with the first east winds of spring; and
while this circumstance is most common on those of England, as for example,
in Kent, Essex, Norfolk, [p046] Suffolk, and Lincolnshire, it is not thus limited,
since it is known to happen further north, and even in Scotland, where
malaria is not indigenous to the soil. It is very true that if we take any inland
position in the places thus noted, the natural solution is, that the malaria is
generated in the very soil itself of England, and merely propagated, perhaps
even to very moderate distances, through those winds. But the occurrence of
disease cannot be explained thus, when the place in question is so situated
that there is no land to the eastward, or when the breeze is, most literally and
rigidly, a sea breeze; while, when ague thus occurs on the east coast of
Scotland, where it is not produced by the soil, it must be imported by the east
wind.
These are the facts; while as malaria is not produced by the sea itself in any
known circumstance, though a vegetating sea beach may give rise to it, we
must seek the cause in lands far distant, and consider this as a case of
propagation of the poison from the shores of Holland; and those shores are
unquestionably competent to that effect: so that the only question that
remains, the fact being admitted, is, whether, à priori, or theoretically, such a
view is probable, or whether it is consistent with those physical principles
that are concerned in the propagation of malaria.

I am aware that such a view will excite the incredulity of those who have
not attended to this subject; though it appears to me that it comprises nothing
averse to our knowledge of the philosophical circumstances concerned. In the
first place, let us remark that the east wind, and particularly the east winds of
spring, are notorious for their moisture, and that a moist air is the best
conductor of malaria, as moisture in the air, under the form of evening mists,
or in other modes, appears even to be its proper vehicle, or residence, if I may
use such a term; and though I have not as yet separated the case of a fog, I
may now remark, that the effect in question, or the production of agues by
fogs arriving from the sea, is even more notorious than their generation by an
ordinary clear wind. So notorious and popular, indeed, is this fact, that the fog
itself is deemed the source of the disease, as the east wind under any form is,
in other circumstances; while I hope it will even now appear, [p047] that the
real cause lies in the malaria transported or conveyed by those winds or fogs,
and of which they are the true and best repository and vehicle.
And these are the reasons for thinking that the malaria, with the wind, may
be transported to a distance as great as that which the present view requires;
most easily perhaps in a fog, but without difficulty even in a clear wind. It is
remarkable that the east wind, as it is the most persevering, is that one also
which preserves the most steady horizontal and linear course. I have also
shown, in a former work, that it is a property of winds to travel in distinct
lines through a tranquil atmosphere, and often in streams of a very limited
breadth; that opposing streams will also move, in absolute contact; and that
even rapid streams of wind will cross each other’s courses without difficulty.
This proves that, in any such stream, there is a principle of self-preservation
or integrity, and renders it probable that the several portions retain the same
relative places to each other, at any distance, during the career of the whole;
and there is a proof of this afforded in the fact of those columns or streams of
insects which are brought over by such winds, and very frequently from those
very countries, or from Holland and Flanders, in the most regular order, or
without disturbance or dispersion.
Hence it may be argued, that if a malaria, generated any where and
conveyed by the winds, can be transported to a distance of three miles, as has

been proved, there is no reason why it should not travel much farther, or to
any distance that can be assumed: and if this be true of a clear wind, the case
of a fog is even a much stronger one; since there is little reason to doubt that
the individual parts of such fog, in any assumed mass, will retain their
relative places to each other, as perfectly after a journey of any given number
of miles, as they did at the point of production; and if a portion of malaria has
been united to a portion of fog, in the marsh which produced both, or whence
both have come, there is every apparent reason why it should be found in that
same portion at any farther or assumed distance, because there is no cause for
either its dispersion or its decomposition.
A fog is a cloud, simply; and it is notorious that a single [p048] cloud, and
often of very small dimensions, will remain at rest in the atmosphere, or
travel very many miles without the loss of its integrity; however we may
imagine it assailed by the various meteorological causes of destruction, as
well as by mechanical violence. This in itself proves the consistency with
which a current of wind preserves the relative positions of its integral parts;
because it is plain that a disturbance among these must disturb or destroy the
cloud which, in reality, forms a portion of that current, as a gaseous body: and
since that cloud is a mist, since it might have been the very evening mist
embodying a malaria, and since it is its real vehicle and repository, it is plain
that had it, or any individual cloud, contained such a portion of malaria, it
must have had the power of transmitting that, and would actually have
transported it to any distance to which itself might travel. Thus, it is evident,
may a fog, generated in Holland, carry without difficulty to the limits of its
range, or to the coast of England, that malaria which became entangled with
it at its birth-place or in its passage; and thus, I have little doubt, is the fact of
those agues explained, and this transportation to such distances established.
I cannot, at least, conceive any demonstration as to facts of this nature
more convincing, nor anything wanting to the proof; while I may proceed to
make some remarks on the east wind, and on fogs, simply, because they
concern this question.
The proof that it is a malaria in the fog, and not the fog itself, which is the
cause of disease, is evinced by the following fact; while it ought surely to be

unnecessary to say, that if fog alone could produce such fever, water itself
must be the poison: since a fog is a cloud, and its constituents, when pure, are
only atmospheric air and water. No intermittents are ever produced on the
western or northern shores by the sea fogs, and for the plain reason, that there
is no land whence they arrive. The clouds of mountainous regions do not
produce fevers, though these also are fogs; and what forms a most absolute
proof of this is, that in Flanders, it is the fogs which come with a southwest
wind, or the southerly winds themselves, which transport and propagate
malaria and disease; while; as soon as the winds shift, and blow from the sea,
the fevers [p049] disappear, though those particular winds are so charged with
fog, as to darken the whole country for days: and it will be found an
invariable rule all over the world, that when a fog is the apparent cause of
disease, or when an east wind is such, it is because these have been generated
in a land of marshes, or have traversed one; and that, under other
circumstances, or where no pernicious land lies in the way, they are as
innocent as any other fogs and winds, and that the hazard and the suffering
will arise from those, be they whatever they may, which traverse pestilential
lands.
But I must defer this particular and interesting subject to another occasion,
lest I make this article too long; and proceed to examine some other
circumstances connected with the transportation of malaria.
First, however, I must notice one fact as to this transportation from
Holland, partly because it is a necessary fact in the history of malaria, and
partly because it might be used as an argument against the view which I have
just given. The east winds of autumn are not supposed to bring remittents, as
those of spring bring agues, though I cannot assert that this is absolutely true.
Being assumed, the solution is easy. If the winds of this nature in spring, are
notedly moist, and thus vehicles of malaria, the case is exactly the reverse
with the east winds of summer and autumn; or as the east wind may be the
most moist of winds, so may it be the most dry; while it is a consequence of
its extreme dryness, in fact, that it is always the very cause of our burning
summers. This is the history of our last summers, and it is invariable, whether
as it relates to seasons or single days; and it is plainly owing to its permitting

the more ready transmission of the sun’s rays. That it is the very harmattan of
Africa, it is almost unnecessary to say; and as dry wind is not a conductor of
malaria, as that poison is in fact decomposed or destroyed in these
circumstances, daily and invariably, it is easy to see why the remittents of
Holland should not be transported, like its intermittents, though even this may
possibly happen under particular circumstances.
To proceed; and to the next remarkable facts connected with the
propagation of malaria.—The most singular of these is its limitation, or that
yet unexplained property by which it is [p050] determined in a particular
direction, or confined to a particular spot, while it is a piece of knowledge of
some practical value. There is an appearance of incredibility about many of
these facts, and, accordingly, they have not only been disbelieved but
ridiculed, although nothing in the whole history of this substance is better
established.
With respect to direction, in the first place, it is remarked in Italy, currently,
that this poison will enter the lower stories of houses, particularly with open
windows, when the next above escape; and hence, in many places, no one
ventures to sleep on ground floors: and the truth of this was confirmed in the
barracks at Jamaica by Dr. Hunter; as the cases of fever occurring among the
men in the lower rooms much exceeded those which happened in the upper
ones. But I am also informed, that in some places in Norfolk this peculiarity
is reversed; or that there are houses where it is remarked that the ground-
floors are safe, while no one can sleep in the upper stories without hazard.
That malaria may in some manner be attached to the soil is also well
known by its effects, and especially in Italy. There it is remarked that it is
extremely hazardous to cut down certain bushy plants which appear to
entangle it, and that fevers are a frequent consequence of such carelessness.
Thus, also, does fever seize on the labourers who may incautiously sit down
on the ground, while they would escape in the erect posture; being thus,
indeed, sometimes suddenly struck with apoplexy, which is one of the effects
of this poison, or even with death.
It has similarly been observed that it is often retained in the shelter of
drains, or in the ditches of fortifications; whence frequent fevers among the

sentries on particular guards, when the other soldiers escape. And thus was it
even proved at Malta, that it was transported from the sea-shore, and thus
lodged in a dry ditch of the works at Valetta; all these facts being possibly to
be explained, by supposing it possessed of a greater specific gravity than the
atmosphere, or else attached to vapour thus weighty, exhibiting effects
analogous to those which carbonic acid displays in the Solfatara.
But the circumstance most difficult of explanation is, that in Rome, and
numerous places in Italy, and even where it is [p051] transported from a
distance by the winds, not generated on the spot, it is found, perennially, and
through the whole course of successive years, to occupy certain places, and to
avoid, as constantly, others quite near, and, as far as the eye can judge,
equally exposed, and in all respects similar. Thus, one side of a small garden,
one side of a street, or one house, will be for ever exposed to disease, or
uninhabitable, when, at a few feet or yards distant, the very same places are
as constantly free of danger: and thus it was found at the village of Faro, in
Sicily, that all the troops of our army quartered on one side of the single street
which formed it, were affected by fevers, and suffered great mortality, while
those on the other remained in health.
But the most remarkable case of this nature known to me, is a domestic
one, and which rests on the testimony of thousands of persons, or of the
whole country, however incredible it may appear. It is, that between Chatham
and Brighton, including every town and single house, and Sittingbourne
among the rest, the ague affects the left hand side of the turnpike road, or the
northern side, and does not touch the right side, though the road itself forms
the only line of separation.
We cannot as yet conjecture the cause of this very singular circumstance or
property, at least in cases of this nature; though, under certain events of this
kind, there are some facts in meteorology that may offer a solution. These are
the notorious ones, that a hoar frost, or a dew, will sometimes be found most
accurately limited, both vertically and horizontally, by a definite line;
stopping, for example, at a particular hedge, and reaching to a certain altitude
on a tree: but for the other cases, we must yet wait for a period of more
accurate knowledge as to this singular substance.

There is now one circumstance of importance, relating to the destruction or
decomposition of malaria, which must not be passed over, from the interest of
the facts depending on it: this is, that its propagation is checked by the streets
of a crowded town, and apparently owing to this very cause, decomposition.
Thus it is observed, that the fever never appears in the Judaicum of Rome,
and, similarly, that the crowded streets and the poor people escape, when the
opulent houses and open [p052] streets are attacked; and hence the Villa
Borghese, among many other palaces and opulent houses in Rome, has been
abandoned, while such desertion, being limited exclusively to houses where
the air is most open and free, naturally excites wonder: the cause, however, is
now plain; and thus it now appears why it was that the Penitentiary in
Westminster suffered formerly from dysentery, originating in this cause,
when no such disease appeared among the neighbouring inhabitants.
And if this fact is of value as it may relate to the erection of open streets in
any place of this nature, it is most important to point out what has been the
continuous effect at Rome, as the ultimate consequences threaten to be
extremely serious.
It appears that from cutting down some forests which many years ago
occupied the declivities of the hills to the southward of Rome, the malaria
was let in upon that city from the Pontine marshes; and, further, that the
extirpation of a similar wood to the eastward had let in the same poison upon
another quarter. Thus it has been found to enter the city through the Porta del
Popolo, while, for many years past, it has been gradually extending its
influence through the streets; leading annually and successively to the
abandonment of many houses and palaces, and still annually increasing and
extending its ravages; so as, at length, as I understand, to have even become
sensible at the Vatican. And the lines which it follows are distinctly traced out
by the inhabitants; while, as I have already said, it is only the houses of the
opulent which suffer, further than as the abandonment of these may also
influence the inferior ones in their neighbourhood.
Whatever the original cause may be, and however the direction,
abstractedly, may be regulated by the winds and the forms of the streets, or by
local and fixed circumstances, it is plain that the annual extension is the

consequence of desertion, and that as the inhabitants retire from before it, it
acquires the means of making a new step and a further progress; because thus
they withdraw those fires and smoke, or whatever else it be, dependent on
human crowds, which decomposes and destroys this substance. And hence it
must follow, that as Rome shall become still further abandoned and
depopulated, from want of industry, or from political feebleness [p053] added
to this cause, the effects must be expected to increase in a sort of geometrical
ratio; almost leading to the fear that the whole city itself may, in time, fall a
victim to it, or become abandoned to the wolves and mosquitoes.
If I dare not inquire more minutely into the remaining circumstances
connected with the propagation of malaria, lest I should extend this article to
an inconvenient length, it is necessary now to offer some remarks on
prevention, and especially as it relates to this circumstance—the propagation
of the poison; since the rules for prevention, as far as this relates to
production, may be deduced from what was said in a former paper on this
subject, and relate chiefly to the drainage of lands, and to other practices,
more or less obvious, which a little reflection will, without much difficulty,
deduce from what was there said.
It is plain, in the first place, that as far as the winds are concerned, it is by
opposing obstacles to their course that we must attempt to counteract or
divert their influence; and that, in this case, it is through the use of trees alone
that we possess any power. Thus reversely, as in the case just stated, the
cutting down of trees and forests has often been a serious cause of diseases in
certain countries, by admitting a malaria to particular spots; though it is easy
to see that where any given spot suffers from malaria, through condensation
or confinement, the clearing away of these would be the remedy, by attaining
a free ventilation. To detail the particular modes in which remedies may be
applied through this species of aid, is obviously unnecessary, and not easy, as
it must depend on local circumstances, differing for each place; but I may
remark, as an example in illustration of my meaning, that where, as in many
of the narrow and prolonged valleys of Greece, the sea shore is a marsh, the
remedy would be to plant a screen of trees beyond it, and thus to prevent the
sea winds from passing into the interior. And thus did the ancient Romans

compel the planting of trees on the shores of Latium, to check the current
from the Pontine marshes; rendering groves sacred, under heavy penalties,
and enacting other laws with the same intentions.
With respect to such temporary precautions in these cases [p054] as may
concern armies in the field, or in camps, it is plain that they will depend on
attention to the courses and seasons of the winds; while it would be
abundantly easy to accumulate, from the histories of campaigns, the most
fearful examples of mortality produced by neglect of these and similar
precautions, and even down to almost the very date at which I am writing:
and there can be no hesitation in saying, that an intimate and accurate
knowledge of every thing which concerns the production and propagation of
malaria, forms a most important branch in that information necessary to a
soldier, and above all to the quarter-master-general’s department and the
medical staff: while, did I dare to record but a very small portion of the
mortality experienced, not only in our own armies, but in those of Europe at
large, during even the last war, from ignorance or neglect on this subject, it
would, I believe, be found that it almost equalled the mortality produced by
the actual collision of war itself. Walcheren will not soon be forgotten; if we
have ceased to think of our mortal Havannah expedition; and if a French
army at Naples was diminished by twenty thousand men, out of twenty-four,
in four days, from this cause; if Orloff lost nearly his entire army in Paros; if
Hungary has more than once destroyed ten times the number of men by fever
that it did by the sword,—these are but trifles in the mass of reasons for
saying, that no subject can well be more important, and no knowledge much
more necessary to the commander of an army.
Some other points relating to prevention may deserve a few words of
notice, before I pass from this subject; if here, also, I must be brief. Not to
repeat the cautions founded on what relates to the power of evening and
morning, it has been asserted that the use of a gauze veil will prevent the
effect of malaria; and it is not improbable that the air accumulated within
that, may have the power of decomposing the poison: it is an opinion, at least,
which is universal among the people in Malta, and very general in Spain and
Portugal. It is also found that fires and smoke are useful, and especially on

military service; the experiment having been tried on a very large scale by
Napoleon before Mantua, and on a smaller one in Africa, with the most
perfect success. With respect to [p055] personal precautions, it is universally
recommended to use wine and a good diet, and especially never to leave the
house in the evening in situations peculiarly insalubrious, without the
previous use of wine or spirits; whence the universal practice of Holland in
this respect. Thus, also, narcotics prevent its influence; whence the wide use
of tobacco, of which the salutary effects appear to be most amply established.
As to the tropical countries, there is here also one important remark, which,
from the great neglect of the fact, and its ruinous consequences, appear
particularly to demand a statement in this place. It is the universal experience
of the inhabitants, that the attack of malaria, or the production of fevers, is
aided by the use of a full or animal diet; by the use of some particular articles
of food, such as butter; by excess in eating, generally; and, above all, by
eating in the heat of the day. This is not merely well known to the negroes,
but the fact is distinctly stated to travellers, and the caution urged, however
often it has been neglected, and especially by our own countrymen. Of this, in
particular, Major Denham is a strong testimony; while he attributes his own
exclusive preservation to his having rigidly followed the recommendations of
the natives, which were always urged with the greatest earnestness. And if we
examine the causes of death, in most cases, of our African travellers
especially, I think there will be strong reasons for believing that their lives
have often been sacrificed to this very negligence or obstinacy; while it is
most evident that Niebuhr’s party, in particular, owed the loss of their lives to
what may be safely called gluttony: and it is to be suspected that this will also
explain the loss of Captain Tuckey’s party; while, with respect to nations, it
has long been known that the English, the Dutch, and the northern voracious
people in general, who habitually indulge themselves in the customs of their
original country as tropical colonists, have always been greater sufferers from
the effects of those climates than the French and the Spaniards, and
apparently from this very difference. And there seems little doubt, generally,
that the vegetable diet of Africa and Hindostan is the best security against the
evil influence of those climates, and that the chief sufferings of our [p056] own

colonists arise from transferring to those situations their ancient habits of full
and free living.
As I must not prolong this subject much further, I shall now pass to a few
remarks, but very brief ones, on the geography of malaria as it relates to those
parts of the continent of Europe most frequented by English travellers; not
daring to take room for actual and useful information on that head, but
wishing to point out merely the importance of such geographical knowledge
to those persons, on account of the hazards which they so universally incur
from that ignorance or neglect, and of the great mass of suffering, and also of
mortality, which has been the lot of persons who had resorted to those
climates as travellers, or migrating residents, from various motives, and not
unfrequently with views to health. How often health has been lost where it
was sought, will be but too apparent to any one who has chanced to possess
an extensive acquaintance of this nature.
Of Italy I can but afford to say generally, that except at a very few points
where the Alps or Apennines reach the sea, the whole of its shores are
pestilential, and often to such a degree as to lead to their entire desertion,
more frequently to their abandonment in summer. And to avoid wet lands, or
low lands, is not always a sufficient precaution; since the most pestilential
parts of the maremma of Tuscany are dry, and since the annual mortality of
Sienna from fevers, even without epidemics, is one in ten. In the north of
Italy, the great plain is similarly insalubrious; though the more unhealthy
district does not commence until we arrive at Mantua, extending thence to the
sea. Of the Mediterranean islands, I can only afford room to say, that the
same rule holds good as to the sea coasts, while the entire of Greece in the
same circumstances is similarly unhealthy, and subject to autumnal fevers in
as great a degree as the worst parts of Italy. The same is true of Spain and
Portugal, and the same rule also will be a guide; namely, that malaria is to be
expected in all the flat grounds, even when under cultivation, and at all the
exits of rivers on the sea, even though no marshes should be present: and if I
were desirous to name any tract of land in Spain peculiarly [p057] insalubrious,
it would be the province of Valencia; while Carthagena is almost invariably

fatal even to those who, as labourers, are compelled to resort to it for the
needful work of its port, even during a few days.
Of France, little as it has hitherto been suspected by those who, associating
the term malaria with Italy, have been accustomed to consider it as peculiar to
that country, it would scarcely be untrue to say that it contains as large a
portion of insalubrious territory as Italy itself, and produces fever and disease
of as great severity and extent, not merely on its sea coasts, but over very
extensive tracts in its interior. And this insalubrity may be conjectured, when
there are entire districts in which the average of life does not exceed twenty,
and in which the entire people are diseased from their births to their graves.
Such tracts are found chiefly on the course of the Loire, and some other of the
great rivers; and among them, Bresse in the Lyonnais, the plain of Forez, and
Sologne in the Orleannais, are of the most notorious; while the coasts of
Normandy, and the whole of low Britanny, are similarly subject to eternal
intermittents, or to epidemic seasons of autumnal fevers, amounting to
absolute pestilences. And how English families have suffered in this country
from the incautious choice of residences in such places, will be easily
ascertained by whoever shall be at the trouble of making the necessary
inquiries.
But as I dare not pursue this extensive subject, I can only suggest to our
countrymen the utility of making themselves acquainted with this matter, and
with this dangerous geography, before encountering the hazards which await
them; while to physicians I need still less name the necessity of that
knowledge, since it is so often their duty to choose and recommend for their
patients, and since no man can feel much at his ease who finds that he has
sent into a land of malaria the patient who has already been suffering from its
diseases, or that where he speculates on the cure of a consumption, that cure
is attained through the death of the patient, at Avignon, or at Poitiers, or
Nantes, or in some or other of the numerous places subject to this most
fearful poison.
It remains only to give a brief enumeration of the diseases [p058] which are
the produce of malaria, and of the general condition of the inhabitants in the
countries subject to it. With respect to this latter, the most remarkable general

fact is the contracted duration of life. In England, the average may, if not very
accurately, and indeed considerably under the mark, be taken at 50; and when
in Holland it is but 25, it follows that the half of human life is at once cut off
by this destructive agent. In the parts of France to which I have alluded, it
becomes as low as 22 and 20, and Condorcet, indeed, has calculated it as low
as 18. With this, very few attain the age of 50; and in appearance and
strength, this term is equivalent to 80 in ordinary climates; while 40 forms the
general limit of extreme and rare old age. The period of age, indeed,
commences after 20; and it is remarked, in particular, that the females
become old in appearance immediately after 17, and have, even at 20, the
aspect of old women. In many places, even the children are diseased from
their birth; while the life which is dragged on by the whole population, is a
life of perpetual disease, and most frequently of inveterate and incurable
intermittents, or of a constant febrile state, with debility, affections of the
stomach, dropsy, and far more than I need here enumerate.
While the countenances of the people in those countries are sallow or
yellow, and often livid, they are frequently so emaciated as to appear like
walking spectres, though the abdomen is generally enlarged, in consequence
either of visceral affections or dropsy. With these, rickets, varices, hernia,
and, in females, chlorosis, together with scorbutic diseases, ulcers, and so
forth, are common; and it is even to be suspected that the cretinage may
depend on this cause, since goitre is also one of the results of malaria, and
since, in the Maremma of Tuscany, idiotism is a noted consequence of this
pestilential influence.
The general mental condition is no less remarkable; since it consists in an
universal apathy, recklessness, indolence, and melancholy, added to a fatalism
which prevents them from even desiring to better their condition, or to avoid
such portion of the evils around them as care and attention might diminish:
and while it is asserted that even the moral character becomes [p059] similarly
depraved, I prefer a reference to Montfalcon for a picture which it would not
be very agreeable to transcribe.
As to the absolute or positive diseases, besides those which I have already
named, I need scarcely say that remittent and intermittent fevers, under

endless varieties and types, form the great mass; and next in order to them,
may be placed dysentery and cholera, together with diarrhœa. To these I must
also add, those painful diseases of the nerves, of which sciatica stands
foremost, and the remainder of which may be ranked under the general term
of neuralgia; and further, a considerable number of inflammatory diseases of
a more or less remittent type, among which rheumatism under various forms
is the most general, and the intermittent ophthalmia the most remarkable.
Lastly, I must include the various paralytic affections; since apoplexy is one
of the primary and direct consequences of malaria, as various paralytic
affections are the produce of intermittent, or the consequences of the diseases
of the nerves which are associated with it.
It is still a curious and interesting fact, that this poison affects, in an
analogous manner, many different animals, and appears, in reality, to be the
cause of all the noted endemics and remarkable epidemics which occur in the
agricultural animals in particular. This has been noticed even by Livy: and in
France and Italy it is equally familiar that the severe seasons of fever among
the people are similarly seasons of epidemics to black-cattle and sheep, while
the symptoms are as nearly the same as they could be in the circumstances,
and the appearances on dissection also correspond. Thus also does it appear
probable, that the rot in sheep is actually the produce of malaria, as is indeed
the received opinion among French veterinarians; while Mr. Royston has
observed that the animals of this class are subject to distinct intermittents.
And while it is not less familiar in the West Indies, and in Dominica
particularly, that dogs suffer from a mortal fever in the same seasons and
periods as the people, the epidemic always breaking out in them first, I have
the most unexceptionable medical evidence of the occurrence of a regular and
well-marked tertian in a dog; that evidence consisting in the concurring
decision of many surgeons, by whom the case was [p060] frequently examined,
during a very long period. But it is time to terminate a paper, which, if it is
but a sketch of an important subject, will at least convey to those to whom
malaria has not hitherto been an object of attention, a general notion of the
leading particulars which appertain to its natural history. J. M.

Elements of Chemistry, including the recent Discoveries and Doctrines of the
Science. By Edward Turner, M.D., F.R.S.E., &c., &c. Edinburgh, 1827. ◊

T HIS is a closely-printed octavo of 700 pages, and presents us with something
more original, clear, and accurate than we have lately met with in modern
chemistry. It comprehends a perspicuous view of the present state of chemical
science; and, as far as its limits admit, the theoretical parts are, with some
exceptions, well and distinctly worked out; nor are the practical details of
manipulation neglected, though they evidently occupy a secondary place in
our author’s estimation. To the arrangement we must at once decidedly object
—it is indeed evident that Dr. Turner has pitched upon Dr. Thomas Thomson
as his magnus Apollo, and here and elsewhere the book is tainted accordingly.
This work is divided into four principal parts;—the first relates to what Dr.
Turner, following his prototype, Dr. Thomson, calls imponderables, and a
definition of them follows, which leads us to suggest the term inexpressibles,
as equally appropriate. But, waiving this objection, the details relating to
them are well and clearly given. Thus, after some prefatory remarks upon the
subject of caloric or heat, (we prefer the latter term, and cannot allow its
ambiguity,) its modes of communication are considered, first, as being
conducted through bodies, and then as radiating through free space. In regard
to the theories affecting the latter, our author wisely, as we think, prefers that
of Prevost to that of Pictet. The effects of heat are next discussed, such as
expansion, including an account of the thermometer, and of the relative
capacities of bodies for heat; liquefaction, vaporisation, ebullition,
evaporation, and the constitution of gases and lastly, the sources of heat are
mentioned, but the details are referred to other parts of the work. [p061]
Light is next treated of, but we think too hastily, and too much in the
abstract.
Now the subjects of heat and light are obviously of the utmost importance
to the chemical philosopher, and they are very extensive, and intricate and
difficult to treat of, inasmuch as the writer is necessarily upon the confines of
chemical and mechanical philosophy, and should be expert in both. When,

therefore, elementary works on chemistry are so written and arranged as to
serve as text-books for lectures, and indexes of reference to more accurate
information, we can make due allowance for brevity; but when the subject is
intended to be formally and completely developed to the student, independent
of other ocular and oral aids, much more extensive description and detailed
explanation is required, than is to be found either in our author’s “Elements,”
or in any other analogous condensation of chemistry. Dr. Henry understands
the requisite mode of conveying information in these cases better than most
writers; and when he takes pains, and speaks for himself, has the talent of
being brief, and at the same time minute, deep, and clear. Dr. Ure, as his
dictionary shows, is an eminent example of such a writer—he of course is
neglected, where, as with our author, Dr. Thomson is in the ascendant; but the
article caloric, in his dictionary, will at once explain and illustrate our
meaning, and would furnish an admirable foundation for a detailed essay or
treatise upon the subject. So extensive, indeed, are the precincts of chemistry
now becoming, that either our systems must become very voluminous, or we
must adopt the plan, which to us appears preferable, of distinct treatises upon
different branches of the science. Thus, a separate work on heat and light;
another on electricity and magnetism; another on attraction and the theory of
combination; a fourth on the constitution and properties of the unmetallic
elementary bodies; a fifth on the metals and their compounds; a sixth on
vegetable, and a seventh on animal chemistry and physiology; an eighth on
the chemistry of the arts; and lastly, a treatise on chemical manipulation in
general, would include all that appears essentially requisite; and as no one is
supposed to be equally well versed in all branches of the science, or in all
details of the art, an opportunity of selection would thus be afforded, so that
each writer might choose that particular department which he is most
accurately acquainted with, or which has formed his favourite study. Mr.
Faraday has already, as may be said, led the way in such a plan, by the
publication of his Chemical [p062] Manipulation, a work hitherto exceedingly
wanted in the laboratory, equally useful to the proficient and to the student,
and eminently creditable to the industry and skill of the author, and to the
school whence it emanates. We shall of course take an early opportunity of

introducing this book in a more formal way to the attention of our chemical
readers.
In looking over Dr. Turner’s first and second sections on caloric and light,
in the Elements now before us, we find little but brevity to complain of;—
there are, however, one or two trifling historical inaccuracies: thus, at page
14, the discovery of invisible heating rays is ascribed to Saussure and Pictet;
but it is, in fact, of much more remote origin—it was well known to the
Florentine academicians, and we may even trace the idea in Lucretius, (De
Rerum Naturâ, lib, v. 1, 609.)
Forsitan et rosea Sol alte lampade lucens
Possideat multum cæcis fervoribus ignem
Circum se, nullo qui sit fulgore notatus, &c.
At page 31 we have an account of Wedgwood’s pyrometer, which is said to
be “little employed at present, because its indications cannot be relied on;”—
the fact is, that it is never used, and that we owe to Sir James Hall ample
reasons for placing no confidence in it.
The subject of specific heat is clearly explained, and so are the phenomena
of liquefaction and evaporation. In regard to the constitution of gases, the
author remarks, that the experiments of Sir H. Davy and Mr. Faraday on the
liquefaction of gaseous substances, appear to justify the opinion that gases are
merely the vapours of extremely volatile liquids. Mr. Faraday has proved this
in regard to several of the gases, and analogy leads us to apply it to the rest;
—but what share Sir H. Davy had in the discovery, we know not; for Mr.
Faraday actually condensed chlorine into a liquid before Sir H. had heard or
thought about the matter. Light, and its phenomena as connected with
chemistry, is superficially passed over in the second section, and the third
brings us to the important article “Electricity.”
We are willing to admit that the subject of electricity is a very difficult one
for the chemist to deal with—he must necessarily say much upon it, and is
equally obliged to omit abstract details which are often necessary to its
explanation, and yet too prolix and bulky for an elementary chemical work.
So that it requires considerable acquaintance with the subject to give a
perspicuous and yet concise abstract, [p063] such as may be useful to the

student. Dr. Turner has not been very successful in effecting this desideratum,
and has unnecessarily introduced two sections, the one on electricity, the
other on galvanism. He also talks of the “science of galvanism,” which is in
bad taste, and erroneously asserts that the energy of the pile is proportional to
the degree of chemical action which takes place; a statement by no means
correct, inasmuch as the energy of De Luc’s column is directly proportional
to the number of alternations, and appears entirely independent of chemical
action; and again, a series of 2000 plates, arranged in the usual Voltaic
apparatus, when perfectly bright and clean, and the cells filled with distilled
water only, give a much more powerful shock, and cause a greater divergence
of the leaves of the electrometer than when the apparatus is charged with
diluted acids. Here, those very singular phenomena, which electricians
distinguish by the terms quantity and intensity, appear perfectly distinct; and
between these our author does not sufficiently discriminate, but jumbles the
whole under the term activity. In describing the chemical energies, too, of the
pile, or its decomposing powers, the Doctor entirely overlooks the important
and curious influence of water. He says that acids and salts are all
decomposed, without exception, one of their elements appearing at one side
of the battery, and the other at its opposite extremity; (i. e. we presume, at its
positive and negative poles.) But the fact is, that, excepting where it merely
acts as a source of heat, nothing is decomposable by electricity without the
intervention of water; the hydrogen and oxygen of which respectively
accompany the elements of the other compounds. Not an atom of potassium
can be obtained unless the potassa be moistened; nor can any salt be
decomposed except water be present. Sir Humphry says, it is required, to
render the substance a conductor; but its operation is more recondite, and
there is something mysterious and still unexplained in the uniform
appearance of hydrogen and oxygen at the opposite poles, when far apart in
water, and in all other cases of true polar electro-chemical decomposition. At
page 86, the unfortunate protectors of ships’ bottoms are introduced—a
subject about which the less is said the better;—and, as to electro-magnetism,
it is merely mentioned as to its leading phenomena, in the space of three or
four pages; nor is anything new suggested upon the “Theory of the Pile,” as it

is called, which concludes the subject, and which is dismissed in the brief
limit of a page and a half. [p064]
The second part of Dr. Turner’s work is said to comprise “Inorganic
Chemistry,” and therefore embraces a very extensive field of inquiry. To the
arrangement we have already objected; and many of the typographical and
verbal errors that occur, have been noticed in a contemporary Journal, so that
we shall chiefly attend to the details of the sections.
Under the head, “Affinity,” some of the leading facts and doctrines of
chemical attraction are perspicuously set forth; but we could have wished that
a variety of exploded opinions and erroneous notions had been altogether
passed over, as they occupy space which might have been better employed,
and can never prove of any other use to the student than to show him the
errors and fallacies to which acute philosophers are sometimes liable. Of this
kind, especially, are Berthollet’s notions upon the subject of affinity. The
doctrine of definite proportion is, on the whole, well and clearly explained;
but it would have been much better and clearer, had Dr. Turner confined
himself to facts, and meddled less with opinions concerning their cause; he is
moreover, in many respects, historically inaccurate. He ascribes much to
Dalton that honestly belongs to Higgins;—is much too merciful to Berzelius
and his C ANONS ; and lenient beyond all endurance to the plagiarisms of “Dr.
Thomson’s admirable Treatise on the first Principles of Chemistry.”
In the third and following sections, the simple non-metallic substances are
described in an order of arrangement which must be very perplexing to the
student; otherwise the details are well given, except that here and there the
line between theory and fact is not sufficiently marked. Thus we are told that
“hydrogen is exactly 16 times lighter than oxygen, and therefore that 100
cubic inches must weigh 33.88816
, or 2.118. Its specific gravity is consequently
0.0694, as stated some years ago by Dr. Prout.” Now this is a theoretical
deduction, founded upon the specific gravity and constitution of ammonia,
(and not upon the composition of water,) and probably correct as applied to
pure hydrogen;—but if we weigh the gas, as usually obtained, even with the
utmost caution, and of the utmost purity, we shall never procure it so light as
here stated, notwithstanding all the learning and argument that our worthy

friend, Dr. Thomas Thomson, has issued upon the subject in his various
essays in the Annals, and in his magnum opus. We also object to the stress
which is often laid upon the whims of individuals, and upon [p065] exploded
opinions; instances of which will occur to the reader under the subject of the
composition of nitrogen, and the constitution of the atmosphere. We further
caution our author against admitting hints, allusions, and inuendos as to the
possibility of future inventions and discoveries, as claims upon the merits of
such discoveries, when they are actually made. Berzelius has talked a vast
deal of nonsense about the composition of nitrogen; and should that
discovery ever be made, he will doubtlessly assume the credit of having
suggested the steps which led to it. Some foolish persons are apt to think that
the Marquis of Worcester was the inventor of Watt’s steam-engine, because
he said he had means of raising water by steam, in his Century of Inventions;
and we have heard that an eminent chemist of the present day considers
himself entitled to all the merit that may belong to Mr. Brunel’s carbonic acid
engine, because he had previously stated the possibility of such an application
of Mr. Faraday’s important discoveries. The fact is, that these are woeful days
for science; all the good feeling and free communication that used to exist
among its active cultivators in this country, has given way to petty jealousies
and quibbling scandal; one person is exalted for the purpose of depreciating
another; and those causes of disgust, which some years ago induced one of
our most amiable and able men of science to quit the field, and even leave the
country, are becoming daily more prevalent. Were it not an invidious task, we
could easily explain and unfold the sources of all this mischief, and shall
indeed feel it our duty so to do, should not matters in due time take a more
favourable turn; but the task is at once serious and disagreeable, and we
therefore postpone it, in the hope of more favourable events. We really
believe that, had it not been for the scientific conversationes held during the
last season at the houses of a few private gentlemen connected with the
learned societies, and more especially the weekly meetings at the Royal
Institution, which kept up a friendly intercourse among those who were
willing to profit by it, that the whole scientific world would have been at

loggerheads, and in that state of anarchy of which the evils may be learned by
a short residence at a “northern seat of learning.”
The main object of this digression is to deprecate party in science; and we
were led to it by observing, or thinking that we observe, something of such a
tendency in the writer whose book is before us—we hope we are mistaken.
The next section comprises “the compounds of the simple [p066] non-
metallic acidifiable combustibles with each other.” It includes the important
subject of ammonia, of the varieties of carburetted hydrogen, sulphuretted
and phosphuretted hydrogen, and cyanogen and its compounds. The metals
are then treated of, and to these succeed their salts; and though the execution
of this part of the work betrays some haste, it shows also considerable
reading, and some originality: the general views are well and clearly
sketched, but there are many points upon which we are entirely at variance
with our author; and we more especially object to his account of the action of
chlorides upon water, and to his notions concerning the “muriates of oxides,”
a class of compounds of which, with one or two exceptions, we are
disinclined to admit the existence. If common salt be a chloride of sodium,
and experiment obliges us so to regard it, what is there in its aqueous solution
that should lead us to consider it as containing a muriate of soda; what
evidence of any new arrangement of elements? Dr. T. is certainly in mistake,
when he says, “for all practical purposes, therefore, the solution of a metallic
chloride in water may be viewed as the muriate of an oxide, and on this
account I shall always regard it as such in the present treatise.” This
inconsiderate dogma taints much of the reasoning upon the chlorides, &c.,
and is manifestly culled in the Thomsonian school, though we have indeed
heard that a Professor at Edinburgh thus addresses his pupils upon the above
subject: “The elaborate researches of the illustrious Davy have taught us that
common salt is a binary compound of chlorine and sodium, a chloride,
therefore, or a chloruret of sodium. But it is only chloride of sodium whilst
quiescent in the salt-cellar; for no sooner does it come into contact with the
salivary humidity of the fauces, than, by the play of affinities, which I have
elsewhere explained, the sodium becomes soda, and the chlorine generates
muriatic acid;—that, therefore, which upon the table is chloride of sodium, is

muriate of soda in the mouth; and this again, when desiccated or deprived of
humidity, retrogrades into its former state.”
Dr. Turner again falls into error, as we humbly conceive, in calling certain
salts, such, for instance, as those of the peroxide of iron, sesquisalts, a term
properly applied in those cases only where one proportional of a protoxide
unites with one and a half of an acid, such for instance as the sesquicarbonate
of soda, &c., but in the sesquisulphate of iron, one proportional of the
peroxide contains 1.5 of oxygen, and [p067] necessarily, therefore, (according
to Berzelius’ canon, if the Doctor pleases,) requires 1.5 of acid to convert it
into a salt; just as the commonly constituted peroxides (containing two
proportionals of oxygen) require two of acid. Dr. Thomson, with all his
nomenclatural pretensions, has fallen into the same error.
The part of our author’s work which treats of the chemistry of organic
bodies is, upon the whole, an unexceptionable and accurate epitome of that
complicated branch of the science. It has its inaccuracies, but they apparently
arise out of the difficulty of condensing into the space of a few pages, matter
which, as we have elsewhere remarked, would require an ample volume for
its extended and perspicuous details.
In our hasty account of this work, we have rather dwelt upon its defects
than its merits, in the hope of seeing another and more extended edition, free
from what we consider as serious obstacles to the success and usefulness of
the present production. We hope that Dr. Turner will not feel offended at the
freedom with which our remarks are offered. We are anxious that a writer of
such good information should be induced to think for himself; at least, that he
should accurately weigh the pretensions, and inquire into the originality of
those views and researches upon which he bestows such unqualified and, in
our opinion, undeserved praise, and to which he assents with a facility
unbecoming one who evidently possesses the means of testing their merits.

Experiments on Audition. ◊
[Communicated by Mr. C. Wheatstone.]

T HE recent valuable experiments of Savart23 and of Dr. Wollaston have added
to our stock of information several important and hitherto unnoticed
phenomena relating audition; but, notwithstanding the investigations of these
distinguished experimentalists, and though the physiology of the ear has been
an object of unceasing attention for many centuries, yet we are far from
possessing a perfect knowledge of the functions of the various parts of this
organ. The description of new facts illustrative of this subject cannot,
therefore, be devoid of interest; [p068] and though I do not anticipate that the
observations contained in this communication will lead to any important
results, their novelty may claim for them some attention from the readers of
your Journal.

§ 1.

If the hand be placed so as to cover the ear, or if the entrance of the meatus
auditorius be closed by the finger without pressure, the perception of external
sounds will be considerably diminished, but the sounds of the voice produced
internally will be greatly augmented: the pronunciation of those vowels in
which the cavity of the mouth is the most closed, as e ou, &c., produce the
strongest effect; on articulating smartly the syllables te and kew, the sound
will be painfully loud.
Placing the conducting stem of a sounding tuning-fork24 on any part of the
head, when the ears are closed as above described, a similar augmentation of
sound will be observed. When one ear remains open, the sound will always
be referred to the closed ear, but when both ears are closed, the sound will
appear louder in that ear the nearer to which it is produced. If, therefore, the
tuning-fork be applied above the temporal bone near either ear, it will be
apparently heard by that ear to which it is adjacent; but on removing the hand
from this ear (although the fork remains in the same situation) the sound will
appear to be referred immediately to the opposite ear.
In the case of the vocal articulations, the augmentation is accompanied by
a reedy sound, occasioned by the strong agitations of the tympanum. When
the air in the meatus is compressed against this membrane by pressing the

hand close to the ear, or when the eustachian tube is exhausted by the means
indicated by Dr. Wollaston, the reedy sound is no longer heard, and the
augmentation is considerably diminished. The ringing [p069] noise which
simultaneously accompanies a very intense sound, proceeds from the same
cause, and may be prevented by the same means. This ringing may be
produced by applying the stem of a sounding tuning-fork to the hand when
covering the ear, or by whistling when a hearing trumpet is placed to the ear.
As a proof that the resulting augmentation, which, when great, excites the
vibrations of the tympanum, is owing to the reciprocation of the vibrations by
the air contained within the closed cavity, it may be mentioned, that when the
entrance of the meatus is closed by a fibrous substance, as wool, &c., no
increase is obtained.
If the meatus and the concha of one ear be filled with water, the sounds
above-mentioned will be referred to the cavity containing the water in the
same way as when it contained air, and was closed by the hand; it will be
indifferent whether any partition be interposed between the cavity and the
external air; as the water is equally well insulated by a surface of air as by a
solid body.

§ 2.

The preceding experiments have shown, that sounds immediately
communicated to the closed meatus externus are very greatly augmented; and
it is an obvious inference, that if external sounds can be communicated, so as
to act on the cavity in a similar manner, they must receive a corresponding
augmentation. The great intensity with which sound is transmitted by solid
rods, at the same time that its diffusion is prevented, affords a ready means of
effecting this purpose, and of constructing an instrument, which, from its
rendering audible the weakest sounds, may with propriety be named a
Microphone.
Procure two flat pieces of plated metal, each sufficiently large to cover the
external ear, to the form also of which they may be adapted; on the outside of
each plate directly opposite the meatus, rivet a rod of iron or brass wire about

16 inches in length, and one-eighth of an inch in diameter, and fasten the two
rods together at their unfixed extremities, so as to meet in a single point. The
rods must be so curved, that when the plates are applied to the ears, each rod
may at one end be perpendicularly inserted into its corresponding plate, and
at the other end may meet before the head in the plane of the mesial [p070]
line. The spring of the rods will be sufficient to fix the plates to the ears, but
for greater security ribands may be attached to each rod near its insertion in
the plate, and be tied behind the head.

A more simple instrument may be constructed to be applied to one ear
only, by inserting a straight rod perpendicularly into a similar plate to those
described above.
The Microphone is calculated only for hearing sounds when it is in
immediate contact with sonorous bodies; when they are diffused by their
transmission through the air, this instrument will not afford the slightest
assistance.
It is not my intention in this place to detail all the various experiments
which may be made with this instrument, a few will suffice to enable the
experimenter to vary them at his pleasure.
1. If a bell be rung in a vessel of water, and the point of the microphone
be placed in the water at different distances from the bell, the differences of
intensity will be very sensible. 2. If the point of the microphone be applied
to the sides of a vessel containing a boiling liquid, or if it be placed in the
liquid itself, the various sounds which are rendered may be heard very
distinctly. 3. The instrument affords a means of ascertaining, with
considerable accuracy, the points of a sonorous body at which the intensity
of vibration is the greatest or least; thus, placing its point on different parts
of the sounding board of a violin or guitar, whilst one of its strings is in
vibration, the points of greatest and least vibration are easily distinguished.
4. If the stem of a sounding tuning-fork be brought in contact with any part
of the microphone, and at the same time a musical sound be produced by
the voice, the most uninitiated ear [p071] will be able to perceive the
consonance or dissonance of the two sounds; the roughness of discords, and

the beatings of imperfect consonances, are thereby rendered so extremely
disagreeable, and form so evident a contrast to the agreeable harmony and
smoothness of two perfectly consonant sounds, that it is impossible that
they can be confounded.

§ 3.

Apply the broad sides of two sounding tuning-forks, both being unisons,
to the same ear; on removing one fork to the opposite ear, allowing the
other to remain, the sensation will be considerably augmented.
It is well known, that when two consonant sounds are heard together, a
third sound results from the coincidences of their vibrations; and that this
third sound, which is called the grave harmonic, is always equal to unity,
when the two primitive sounds are represented by the lowest integral
numbers. This being premised, select two tuning-forks, the sounds of which
differ by any consonant interval excepting the octave; place the broad sides
of their branches, while in vibration, close to one ear, in such a manner that
they shall nearly touch at the acoustic axis, the resulting grave harmonic
will then be strongly audible, combined with the two other sounds; place
afterwards one fork to each ear, and the consonance will be heard much
richer in volume, but no audible indications whatever of the third sound will
be perceived.

§ 4.

Very acute sounds, such as the chirping of the gryllus campestris, &c.,
are rendered inaudible by exhausting the air from the Eustachian tube, and
thereby producing a tension of the membrane of the tympanum; the
different thicknesses or tensions of this membrane may therefore occasion
that diversity of the limits of audibility, with regard to the acute sounds
which Dr. Wollaston has pointed out as existing in different individuals; if

so, it would be desirable to ascertain this limit in individuals in whom the
tympanum is perforated, or destroyed.

§ 5.

When the auricula is brought forward, all acute sounds are rendered
much more intense, but no sensible difference is [p072] perceived with regard
to the grave sounds. The higher tones of glass staccados, or of an octave
flute, the ticking of a watch, all kinds of sibilant sounds, &c. are thus
greatly augmented: the experiment is easily tried, by whistling very shrill
notes. A still greater augmentation of the acute sounds is obtained, by
placing the hands formed into a concave behind the ears, and by bending
downwards the upper part of the auricula, so as to obtain a more complete
cavity.

§ 6.

I will conclude with the following observation: I had, in consequence of a
cold, a very slight pain in my left ear; on sounding the regular notes of the
piano-forte, C3 and C4 were much louder than the others, and the loudness
was much increased, by placing the hand in the manner above described to
the left ear. When it was pressed close, or when the Eustachian tube was
closed, the intensities of all the notes were equalized. I attribute this
affection to the diminished tension of the membrana tympani, which was
again increased by the operation described.

23 Recherches sur les usages de la membrane du tympan et de l’oreille externe; par M. Felix
Savart. Annales de Chimie, tom. xxvi. p. 1.
24 The tuning-fork consists of a four-sided metallic rod, bent so as to form two equal and
parallel branches, having a stem connected with the lower curved part of the rod, and contained
within the plane of the two branches. The branches are caused to vibrate by striking one end
against a hard body, whilst the stem is held in the hand. The sound produced by this instrument
when insulated is very weak, and can only be distinctly heard when its branches are brought
close to the ear; but instantly its stem is connected with any surface capable of vibrating, a great

augmentation of sound ensues from the communicated vibrations. The facility of its insulation
and communication renders it a very convenient instrument for a variety of acoustical
experiments.

On the Petromyzon Marinus. ◊

O N entering the harbour of Dublin a few weeks ago, we were becalmed off
the Hill of Howth, and to pass the tedious time until a breeze sprung up, we
found some lines on board, and began to fish from the quarter-deck. We
caught a number of grey gurnet; but our attention was particularly attracted
by a pull of uncommon force on one of the lines. Having rendered
assistance to the person who held it, we were all astonished to see rise out
of the water a large fish, with apparently a double body, which, after
floundering on the surface of the water, we pulled on deck. On examining
this phenomenon for a short time, we were again surprized to see it separate
into two parts; and then found that there were two large fish taken up on the
same hook, the head of one having been buried under the throat of the other,
to which it had firmly attached itself. When separated by force, it wiggled
about on the deck with extraordinary strength and agility, and again darted
on its prey, to which [p073] it adhered so firmly, that it required very
considerable exertion to detach it; for it suffered itself to be raised up by the
tail, and shaken, still holding the other fish suspended from its jaws. When
finally separated, it showed great ferocity, darting at every thing near it, and
at last seizing the deck, which it held very fast, writhing with its tail and
body as if in the act of tearing it to pieces. When detached, its teeth left a
deep circular impression on the wood, the fibres of which were drawn into
the cavity of its jaws, so as to be raised up in the form of a cone. I now
directed, that it should be put into a bucket of sea water, in the hope of
preserving it alive until we arrived in Dublin, but it died in a shorter time
than could be expected, from the energy and activity it had displayed, long
after the other fish was dead. We had handled it very roughly, and so
perhaps had mortally hurt an animal otherwise very tenacious of life.

On examining the fishes, I found that which had taken the hook, was the
gadus Polachius, or whiting Pollack. It was about two feet long, and it is
probable its active enemy had fastened [p074] on it after it had been hooked;
if before, it would indicate an extraordinary insensibility to pain in an
animal that could attend to the calls of appetite, whilst another was preying
on its vitals. The fish which had fastened on the pollack, was the
petromyzon marinus, or sea lamprey. It was nearly three feet long, and
resembled a large eel in shape. Its general colour was a dull brownish olive
variegated with bluish blotches; the back darker, and the belly paler,
inclining to yellow. The eyes were small, and the mouth large and oval; but

when distended, circular. The inside of the jaws was deeply concave, and
studded with circular rows of sharp triangular teeth, that issued from
corresponding orange-coloured papular protuberances, which formed the
gums; the tongue was short and crescent-shaped, furnished with a row of
very small teeth round the edge. On the top of the head was a small orifice,
or spout-hole, from whence it discharged the superfluous water taken at the
mouth. But the circumstance that more particularly distinguished it, was
that which gave rise to the vulgar error that it had sixteen eyes. On either
side of the neck, commencing just below the real eyes, was a row of seven
equidistant spiracles exactly resembling eyes; they are, however, holes lined
with a red membrane, and all opening into the mouth, an apparatus to
supply the place of gills, whose functions are to extract oxygen from the
water, and so perform the office of lungs in aquatic animals. It had two
dorsal fins, one on the lower part of the back, narrow, with a roundish
outline; the other commencing where the first terminated. The spine was
cartilaginous, without processes. The pericardium, containing a small heart,
was a remarkably strong membrane, and the liver was as green as grass.
This fish is not uncommon in the North Seas, though it most abounds in
the Mediterranean, where, from earliest times, it was esteemed a luxurious
dish. Fish-ponds were purposely constructed to preserve it. On our coast,
Pennant observes, that it is found most frequently at the mouth of the
Severn, which river it sometimes ascends, where it is occasionally taken,
firmly attached to a stone by its mouth, while its tail and body are waving
freely to the current. Its adhesion at such times is so strong, that it may be
lifted with a stone of twelve pounds weight appended to its mouth. This
faculty is owing to its [p075] power of suction; while the circumstance of its
circular jaws coming in close contact with the surface of the body excludes
the external air within the cavity of the mouth, and so adheres like the hand
placed on the cup of an air-pump. It is from this remarkable property, that
its scientific name has been imposed25. Its vulgar name, lamprey, from
lampetra, has a similar derivation. By the Romans it was named muræna.
As this fish was well known and highly prized by the ancients, there is none
that has been so frequently described and alluded to. Aristotle, Pliny,

Tacitus, Columella, Ælian, Seneca, and Oppian, have mentioned its
properties and habits, which correspond exactly with those I have described
above. Pliny says, in the northern parts of France, and consequently
contiguous to the British Isles, the lampreys have seven spots in the jaws,
resembling the constellation of the plough, evidently the same as the eyes,
which vulgar opinion assigns to the fish26. Their extreme voracity was such,
that criminals were thrown among them to be devoured. Seneca relates, that
Vedius Pollio, a Roman knight, ordered his servant, who had broken a
crystal vase, to be thrown into a large pond of lampreys27; and Columella
writes, that they were sometimes seized with a rabid fury, that resembled
canine madness; in the access of which, they seized upon other fish, so that
it was impossible to keep them in the same pond28; and to account for this
extraordinary ferocity, Oppian and others assert, that the lamprey is
impregnated by a serpent; the one issuing from the sea, and the other
rushing down to the rocks, inflamed with madness, to consummate the
impregnation; and adds, that the extraordinary intercourse was effected by
the lamprey seizing the serpent’s head in its [p076] mouth29. This singular
copulation was the reason why the Romans, who were immoderately fond
of lampreys, did not wish to eat them, when impregnated by the supposed
serpent. Horace, therefore, makes Nasidienus, among the blunders of his
supper, serve it in that state30.
Lampreys were a favourite dish with our own early monarchs. Henry II.
died by eating them to excess. The celebrated Pope also owed his death to a
surfeit of them. Doctor Johnson remarks in his life of the poet, that he was
in the habit of cooking them himself in a silver saucepan. The Corporation
of Oxford still make up a periodical pye of this fish for the king, in
compliance with ancient usage. But lampreys have lost their rank at
corporation feasts, in consequence of the more delicious and wholesome
turtle being introduced into modern cookery.
I have never noticed lampreys in the Dublin fish-market; and though they
are frequently used in the South of Ireland, I do not know if they have ever

been made an article of food in Dublin, or the north, where they are rarely
met with.
C.

25 Petromyzon, a πετρον, saxum, and μυζαω, sugere.
26 In Gallia septentrionale murænis omnibus dextra in maxilla septenæ maculæ ad formam
septentrionis aureo colore fulgent. P LIN . Hist. Nat. lib. ix. cap. 39.
27 Fregerat unus ex servis crystallinum ejus; rapi eum Vedius jussit, nec vulgari quadam
morte periturum, murænis objici jubebatur quas ingens piscina continebat.—S ENECA de Irâ, lib.
ii. cap. 40.
28 Commisceri eas cum alterius notæ piscibus non placet, quasi rabie vexantur quod huic
generi velut canino solet accidere. Sævitia persequuntur squamosos plurimosque mandendo
consumunt. C OLUMELLA de Re Rusticâ, lib. ix. cap. 17.
29
Αμφι δε μυραινης φατις ερχεται ουκ αιδηλον
Ὥς μεν γαμει τε και εξ ἅλος ερχεται αυτη
Προφρων ἱμειουσα παρ’ ιμειροντι γαμοιο
Ητοι ὁ μέν φλογεῃ τεθοωμενος ενδοθι λυσσῃ
Μαινεται ἔις φιλοτητα και ἔγγυθι συρεται ἅκτης
Πικρος ὄφις. κ.τ.λ.—O PPIAN , Halieut. lib. i. V. 554.

30
Adfertur squillas inter muræna natantes,
In patinâ porrecta: “hæc gravida,” inquit,
“Capta est.”—H OR. lib. ii. Sat. 8. lin. 46.

Observations upon the Motion of the Leaves of the Mimosa Pudica. ◊
[To the Editor of the Quarterly Journal of Science.]

Dear Sir,
T OWARDS the latter part of this summer, Mr. Gilbert Burnett and myself
made several experiments with a view to ascertain the nature of the
movements exhibited by the sensitive plant. We afterwards found that the
greater part of the facts which we had observed, had been previously
described by Mr. Lindsay [p077] and Dr. Dutrochet. Mr. Lindsay’s

observations are to be met with in a MS. preserved in the library of the
Royal Society, which is dated July 1790: this essay is alluded to by Dr.
Smith in his “Introduction to Botany.” Dr. Dutrochet’s experiments were
published in his “Recherches anatomiques et physiologiques sur la
Structure intime des Animaux et des Végétaux,” which appeared in 1824.
With the latter author the reputation of originality is likely to rest: not
undeservedly, indeed, as there is no reason to suppose that his experiments
were suggested by a knowledge of those performed by Lindsay. It is,
however, an act of literary justice to secure to Mr. Lindsay the credit of
undoubted priority in describing the phenomena which he noticed in
common with Dutrochet. I have drawn up the following remarks partly for
this purpose—partly to have an opportunity of mentioning some
circumstances which escaped the observation of both experimentalists.
The leaves of the Mimosa Pudica consist either of one or two or three
pairs of leaflets, and occasionally terminate by an odd one. Each leaflet
bears from twenty to sixty subleaflets, which are disposed in pairs. The
petiole or stalk of each leaf, at the extremity which is attached to the branch
or stem of the peant, swells into an intumescence varying from three to five
in length. A similar intumescence, of proportionate dimensions, is seen
upon each subpetiole, where it is articulated with the petiole, and upon the
base of the stalk of each subleaflet: the intumescence is the part in which
motion takes place.
During the day-time the petioles are observed to have a direction
upwards, or rather to form an acute angle with the upper part of the stem or
branch, to which they are attached: the subpetioles are divergent: the
subleaflets are spread out, so as to lie nearly in one plane. (Fig. 1.)
During the night the petioles are found to be depressed; the subpetioles to
be drawn together, the subleaflets folded, the upper or solar surfaces of each
pair being brought into contact. (Fig. 2.)

The leaves rise, the leaflets diverge, and open by throwing down their
subleaflets, at daybreak: the opposite changes occur about sunset. The
experiments that are to be described, are supposed to be performed in the
day-time. [p078]

Fig. 1.

If a terminal subleaflet be pinched with
forceps, or cut with scissors, it rises,
together with its fellow; then the next pair
rise; then the next; and so on in succession,
till all the pairs of subleaflets upon the same
subpetiole are folded. In a little time
afterwards, the petiole is bent downwards at
its intumescence; and in a few seconds
more the remaining leaflets upon the same
petiole fold their subleaflets in pairs, from
the base towards the point of the leaflet.
If a subleaflet be burnt, instead of being
cut or pinched, the phenomena above
described occur more rapidly: and after
they have taken place, the adjoining leaves
upon the same branch are bent down in
succession, their leaflets brought together,
and their subleaflets folded. If the plant be
very vigorous and lively, an impression
[p079] made upon one leaf affects the rest in
succession. It is well known that the stem,
branches, flowers, and roots of the sensitive
plant have no motion. But M. Desfontaines
observed that, on touching the roots with
sulphuric acid, the leaves become folded;
and M. Dutrochet obtained a similar result
on burning either the flower or the stem. Fig. 2.

Fig. 3. Fig. 4. Fig. 5.
If the plant be shaken, all the leaves are simultaneously thrown down,
and their leaflets folded. Mr. Lindsay attempted to elucidate the action of
the intumescence in raising and depressing the petiole, in the following
manner. He cut out a portion from the upper or solar surface of the
intumescence; after which he found that the petiole, upon recovering, rose
higher than before, (Fig. 3.) From another leaf he removed the inferior
portion of the intumescence: he found, upon this injury, that the leaf
declined more than before, and did not again rise, (Fig. 4.) He noticed that a
thin slice, pared from either surface of the intumescence, has a like effect,
but in a less degree than a deep excision: and he found that when similar
experiments are made upon the intumescence of the subpetiole, there is no
essential difference in the result.
Thus Mr. Lindsay discovered, that the force which raises the petiole
exists in the lower part of the intumescence, and that which depresses it, in
the upper. He seems to have considered that the temporary excess of force
in either part is produced by an impulsion of the sap from the vessels of the
yielding portion into those of the opposite portion. [p080]
Dr. Dutrochet viewed these phenomena in some respects more justly. He
remarked, in addition to what Lindsay had observed, that if, instead of the
upper and under surface, the lateral part of the intumescence be removed,

the petiole becomes not raised or deflected, but inclined towards the side on
which it is injured (Fig. 5); and that if longitudinal slices of the upper, or
under, or lateral portions of the intumescence are immersed in water, these
separate slices immediately become incurvated, that edge being concave
which looks towards the axis of the intumescence. From these facts
Dutrochet inferred that the texture of the intumescence possesses some
modification of irritability; that, when excited, each length of the
intumescence (to use a very imperfect expression) forcibly assumes an
incurvated figure, like a curved spring returning from a state of temporary
extension; that the petiole is raised, when the action of the lower part of the
intumescence predominates; is depressed, when the upper portion acts with
increased energy.
Mr. Burnett and myself had arrived at very similar conclusions respecting
the agency of the intumescence, before we became acquainted with the
inquiries of Lindsay and Dutrochet.
In Dutrochet’s able researches, a more exact analysis, however, was
obtained of the functions of this part. He discovered that the cortex of the
intumescence is the seat of its irritability: for upon wholly removing the
bark, so as to expose the ligneous substance, the petiole was found to have
been rendered motionless. Nevertheless, the intumescence, thus mutilated,
remains capable of transmitting an impression made upon its leaflets to the
leaves adjoining, Dutrochet further ascertained, that the ligneous substance
alone is fitted to convey the peculiar stimulus, which spreads, from a point
of the plant that has been irritated, to the adjoining leaves.
The experiments already mentioned appear to explain the mode in which
the elevation and depression of the petiole, and the divergence and
approximation of the subpetioles are produced. It is probable that the
contrivance for folding and expanding the subleaflets is of a similar nature.
Mr. Burnett and myself conjectured that each subleaflet is raised by the
under part of the intumescence that exists at its base, and [p081] depressed by
some action of the upper portion of the same intumescence. In trying the
soundness of this hypothesis, we met with the following evidence in its
favour:—

Mr. Lindsay had observed, that at the moment when the petiole is
depressed, the under part of its intumescence assumes a deeper colour. But
the under part of the intumescence of the petiole is the portion which is
shortened during its depression, and which is overcome on this occasion by
the superior force of the upper portion.
Now it is to be remarked that in the subleaflets the upper part of the little
intumescence belonging to each corresponds, in one respect alluded to, with
the lower portion of the intumescence of the petiole; it is the portion
shortened when the leaf is folded. And we found, upon examination, that it
likewise distinctly changes colour at the moment when the subleaflet rises,
while the under surface of the intumescence of the subleaflet does not
change its hue.
In pursuing this inquiry, another point of correspondence between the
mechanism which depresses the petiole, and that which raises the
subleaflets, was stated, which has yet additional interest.

Fig. 6. Fig. 7. Fig. 8.
When the plant is not in its most lively state, the under surface of the
intumescence of the subleaflet (b, Fig. 2,) and the upper surface of the
intumescence of the petiole (a, Fig. 6,) may be pricked with a needle,
without producing action. But if the opposite surfaces, those namely, which
change colour and are shortened when the petiole is depressed and the
subleaflets folded, are touched with the point of the needle these actions are
instantaneously produced. Here the [p082] subleaflet is most delicately
sensible; a slight touch with the point of a needle upon the upper surface of
the intumescence of the subleaflet (c, Fig. 1,) causes the single subleaflet so

stimulated to rise; and in this manner all the subleaflets upon one side of a
leaflet may be raised, their fellows remaining expanded: if the touch be
something sharper, the fellow subleaflet rises at the same time; if ruder still,
the next pair of leaflets fold directly afterwards, and the irritation then
proceeds entirely through the leaflet. But the most satisfactory and curious
results are obtained on stimulating the extension surface of the
intumescence of the petiole. The needle may be applied to every point upon
the upper or solar half of the intumescence of the petiole (a, Fig. 6,) without
producing any visible effect; but if the irritation be applied upon the under
half, (d, Fig. 6,) either quite below or laterally, the petiole is immediately
depressed. The transition is abrupt from the surface against which the
needle may be made to prick, without exciting action, to one which, when
the needle reaches it, causes the petiole to be instantaneously thrown down.
It appears, therefore, that each intumescence has a surface especially
adapted to receive mechanical impressions; which surface is placed on the
side of the intumescence opposite to that, by which the consequent motion
is produced. A curious but vague analogy may be traced between these
surfaces of the sensitive plant and the organs of sense in animals.
We painted with a thick layer of lamp-black in oil the intumescence of
different petioles in different ways; the upper surface of one, the under
surface of another, the side of a third. The experiment was followed by no
sensible effect. After a few minutes the petioles, which had been thrown
down by the operation, rose again in each case, and fell again as readily as
before upon being stimulated afresh.
We tried what result would ensue upon slitting the intumescence of the
petiole horizontally. The petiole, after this injury, did not recover its usual
direction; the intumescence appeared to have wholly lost its properties; the
leaf seemed to depress the petiole by its weight alone, yet the leaflets
expanded, and exhibited their usual irritability, upon the depending stalk.
The same effect, however, was observed, when the [p083] intumescence was
divided by a longitudinal incision, made vertically instead of horizontally.
I have already mentioned that Dutrochet discovered that the ligneous
fibre is the channel, along which an impression is conveyed from one part

to another. Mr. Burnett and myself had made one or two experiments upon
the course which the irritation follows when spreading from leaflet to
leaflet, where several are placed upon the same petiole.
If the upper third of a petiole bearing four leaflets be divided
longitudinally, the irritability of the leaflets remains for many days
unimpaired; upon cutting with scissors one subleaflet after the plant has
recovered itself, the irritation is observed to descend the wounded leaflet,
and then to pass to that adjoining upon the same side of the petiole:
afterwards the petiole falls, but there the effect stops; it does not extend to
the two other leaflets; the direct route is cut through, and the irritation
seems to find no circuitous way, as might have been expected, perhaps
through the intumescence of the petiole back again to the leaflets, on its
summit. If on a petiole, bearing four leaflets, a lateral incision be made,
cutting the petiole half through it at a point between the two leaflets which
are situated on one side, upon irritating either of the leaflets, between which
the incision has been made, it folds its subleaflets; then the two opposite
leaflets fold their subleaflets; and last of all, the leaflet next adjoining that
first irritated, but isolated from it by the incision, becomes folded.
In the few remarks which I have thus put together, I have quoted Lindsay
and Dutrochet only as far as their researches anticipated my own: I leave
unnoticed many experiments, in several of which these authors are again
found to have accidentally coincided. The experiments to which I allude do
not, however, serve to illustrate the nature of the motion exhibited by the
sensitive plant, to the examination of which subject alone my attention was,
in the present instance, directed, in the expectation that it might throw light
upon the obscure and interesting subject of muscular action.
I remain, my dear Sir, Your’s truly,
H ERBERT M AYO .
19, George Street, Hanover Square,
August 29, 1827.
[p084]

Experiments on the Nature of Labarraque’s disinfecting Soda Liquid. By M.
Faraday, F.R.S., Corr. Mem. R. Acad. Sciences, Paris, &c. &c. ◊

1. T HE following experimental investigations relate to the nature of that
medicinal preparation which M. Labarraque has lately introduced to the
world, and named Chloride of oxide of Sodium. They were occasioned by
the accounts which were given of this and other substances of similar
power, to the members of the Royal Institution, at two of their Friday
evening meetings31; the value of the preparation, the uncertainty of its
nature, and the inaccuracy of its name, all urging the inquiry.
2. In the first instance the inquiry was directed to the nature of the action
exerted by chlorine gas upon a solution of carbonate of soda, questions
having arisen in the minds of many, whether it was or was not identical with
the action exerted by the same gas on a solution of the caustic alkali, and
whether carbonic acid was evolved during the operation or not. Chlorine
gas was therefore carefully prepared, and after being washed was sent into a
solution of carbonate of soda, in the proportions directed by M. Labarraque;
i. e. 2800 grains of crystallized carbonate of soda were dissolved in 1.28
pints of water; and being put into a Woulfe’s apparatus, two-thirds of the
chlorine evolved from a mixture of 967 grains of salt with 750 grains of
oxide of manganese, when acted upon by 967 grains of oil of vitriol,
previously diluted with 750 grains of water, were passed into it; the
remaining third being partly dissolved in the washing water, and partly
retained in the open space of the retort and washing vessel. The operation
was conducted slowly, that as little muriatic acid as possible might be
carried over into the alkali. The common air ejected from the bottle
containing the solution was collected and examined; but from the beginning
to the end of the operation not a particle of carbonic acid was disengaged
from the solution, although the chlorine was readily absorbed. Ultimately a
liquid of a very pale [p085] yellow colour was obtained, being the same as

M. Labarraque’s soda liquor, and with which the investigations were made
that will hereafter be described.
3. An experiment was then instituted, in which the effect of excess of
chlorine, upon a solution of carbonate of soda of the same strength as the
former, was rendered evident. The solution was put into two Woulfe’s
bottles, the chlorine well washed and passed through, until ultimately it
bubbled through both portions without absorption of any appreciable
quantity. As soon as the common air was expelled, the absorption of the
chlorine was so complete in the first bottle, that no air or gas of any kind
passed into the second, a proof that carbonic acid was not liberated in that
stage of the experiment. Continuing the introduction of the chlorine, the
solution in the first bottle gradually became yellow, the gas not being yet
visible by its colour in the atmosphere above the solution, although chlorine
could be detected there by litmus paper. Up to this time no carbonic acid
gas had been evolved; but the first alkaline solution soon acquired a
brighter colour, and now carbonic acid gas began to separate from all parts
of it, and passing over into the second bottle, carried a little chlorine with it.
The soda solution in the first bottle still continued to absorb chlorine, whilst
the evolution of carbonic acid increased, and the colour became heightened.
After some time the evolution of carbonic acid diminished, smaller
quantities of the chlorine were absorbed by the solution, and the rest
passing into the atmosphere in the bottle, went from thence into the second
vessel, and there caused the same series of changes and actions that had
occurred in the first. The solution in the first bottle was now of a bright
chlorine yellow colour, and the gas bubbled up through it as it would
through saturated water.
4. When the chlorine had saturated the soda solution in the second bottle,
and an excess of gas sufficient to fill several large jars had been passed
through the whole apparatus, the latter was dismounted, the solutions put
into bottles and distinguished as the saturated solutions of carbonated soda;
they were of a bright greenish-yellow colour, and had an insupportable
odour of chlorine.

5. The saturated solution (4) was then examined as to the [p086] change
which had been occasioned by the action of the chlorine. It bleached
powerfully, and apparently contained no carbonated alkali: but when a glass
rod was dipped into it and dried in a warm current of air, the saline matter
left, when applied to moistened turmeric paper, reddened it considerably at
first, and then bleached it; and this piece of paper being dried and
afterwards moistened upon the bleached part, gave indications of alkali to
fresh turmeric paper.
6. A portion of the saturated solution (4) being warmed, instantly evolved
chlorine gas, then assumed a dingy appearance, and ultimately became
nearly colourless; after which it had an astringent and saline taste. Being
evaporated to dryness at a very moderate temperature, it left a saline mass,
consisting of much common salt, a considerable quantity of chlorate of
soda, and a trace of carbonate of soda. This mixture had no bleaching
powers. The dingy appearance, assumed in the first instance, was found to
be occasioned by a little manganese which had passed over into the
solutions, notwithstanding the care taken in evolving and washing the gas.
7. From these experiments it was evident that when chlorine was passed
in excess into a solution of carbonate of soda (3), the carbonic acid was
expelled, and the soda acted upon as if it were caustic, a mixture of chloride
of sodium and chlorate of soda being produced; with the exception of the
small portion of carbonate of soda which, it appears, may remain for some
time in the solution in contact with the excess of chlorine at common
temperatures, without undergoing this change. The quantities of chloride of
sodium and chlorate of soda were not ascertained, no doubt being
entertained that they were in the well-known proportions which occur when
caustic soda is used.
8. The Labarraque’s soda liquor which had been prepared as described
(2), was now examined relative to the part the chlorine played in it, or the
change the alkali had undergone, and was soon found to be very different to
that which has been described, as indeed the experiments I had seen made
by Mr. Phillips32 led me to expect. The solution had but little odour of
chlorine, its taste was at first sharp, saline, scarcely at [p087] all alkaline, but

with a persisting astringent biting effect upon the tongue. When applied to
turmeric paper, it first reddened and then bleached it.
9. A portion of the solution (2) being boiled, gave out no chlorine; it
seemed but little changed by the operation, having the same peculiar taste,
and nearly the same bleaching power as before. This is a sufficient proof
that the chlorine, though in a state ready to bleach or disinfect, must not be
considered as in the ordinary state of solution, either in water or a saline
fluid; for ebullition will freely carry off the chlorine under the latter
circumstances.
10. A portion evaporated on the sandbath rather hastily, gave a dry saline
mass, quite unlike that left by the saturated solution already described (6);
and which, when dissolved, had the same astringent taste as before, and
bleached solution of indigo very powerfully: when compared with an equal
portion of the unevaporated solution, which had been placed in the mean
time in the dark, its bleaching power upon diluted sulphate of indigo was
30, that of the former being 76. Another portion, evaporated in a still more
careful manner, gave a mass of damp crystals, which, when dissolved, had
the taste, smell, and bleaching power of the original solution, with almost
equal strength.
11. These experiments shewed sufficiently that the whole of the chlorine
had not acted upon the carbonate of soda to produce chloride of sodium,
and chlorate of soda; that much was in a peculiar state of solution or union
which enabled it to withstand ebullition, and yet to act freely as a bleaching
or disinfecting agent; and that probably little or none had combined with the
sodium, or been converted into chloric acid. To put these ideas to the test,
two equal portions of the Labarraque solution were taken; one was put into
a large tube, closed at one extremity, diluted sulphuric acid was added till in
excess, and then air blown through the mixture by a long small open tube,
proceeding from the mouth, for the purpose of carrying off the chlorine; the
contents of the tube were then heated nearly to the boiling point, air being
continually passed through. In this way all the chlorine which had
combined with the carbonated alkali without decomposing it, was set free
by the sulphuric acid, and carried off by the current of air and vapour,

whilst any which had acted chemically upon the alkali would, [p088] after the
action of the sulphuric acid, be contained in solution as muriatic and chloric
acids, and from the diluted state of the whole, would not be removed by the
after-process, but remain to be rendered evident by tests. The other portion
being diluted, had sulphuric acid added also in excess, but no attempt was
made to remove the chlorine. Equal quantities of these two portions in the
same state of dilution were then examined by nitrate of silver for the
quantities of chlorine sensible in them, and it was found that the latter
portion, or that which retained the whole of the chlorine thrown into it,
contained above sixty times as much as the former.
12. Now although it may be supposed that in the former portion that part
of the chlorine, which, in acting energetically, had produced chloric acid,
could not be detected by the nitrate of silver, yet more than a sixth of the
small portion which remains cannot be thus hidden; and even that quantity
is diminished by the sulphuric acid present in excess, which tends to make
the chlorine in the chlorate sensible to nitrate of silver: so that the
experiment shews that nearly 59 parts out of 60 of the chlorine in M.
Labarraque’s liquid are in a state of weak combination with the carbonated
alkali, and may be separated by acids in its original condition; that this
quantity is probably wholly available in the liquid when used as a bleaching
or disinfecting agent; that little, if any, of the chlorine forms chloride of
sodium and chlorate of soda with the alkali of the solution; and that the
portion of chlorine used in preparing the substance which is brought into an
inactive state, is almost insensible in quantity.
13. The peculiar nature of this compound or solution, with the results Mr.
Phillips had shewn me (8), obtained by evaporation of a similar preparation
to dryness, induced me to try the effects of slow evaporation,
crystallization, heat, and air upon it. In the first place five equal portions of
the solution prepared by myself were measured out: two were put into
stoppered bottles, two were put into basins and covered over with bibulous
paper, and one was put into a basin which was left open; all were set aside
in an obscure place, and remained from July 16th to August 28th. Being
then examined, the portions in the basins were found crystallized and dry;

the crystals were large and flat, striated and imperfect, resembling those
formed [p089] in a similar way from carbonate of soda. They were not small
and acicular, were nearly alike in the three basins, and had effloresced only
on a few minute points. A part of one portion, when dissolved, gave a
solution, having an alkaline taste, without any of the pungency of
Labarraque’s liquid; and which, when tested by turmeric paper, reddened,
but did not bleach it.
14. One of these portions that had effloresced least was selected, and
being dissolved, was compared in bleaching power upon diluted sulphate of
indigo, with one of the portions of solution that had been preserved in
bottles. The former had scarcely any visible effect, though sulphuric acid
was added to assist the action; a single measure of the indigo liquor
coloured the solution permanently blue, whereas seventy-seven such
measures were bleached by the portion from the bottle. Hence the process
of slow crystallization had either almost entirely expelled the chlorine, or
else had caused it to react upon the alkali, and by entering into strong
chemical combination as chloride and chlorate, had rendered it inert as a
bleaching or disinfecting agent.
15. From the appearance of the crystals there was no reason to expect the
latter effect; but to put the question to the proof, one of the evaporated
portions, and one of the fluid portions contained in the bottles, were acted
upon by sulphuric acid, heat, and a current of air, in the manner already
described (11), to separate the chlorine that had not combined as chloride or
chlorate. They were then compared with an equal portion of the solution,
which retained all its chlorine, nitrate of silver being used as before: the
quantity of chloride indicated for the latter portion was 60 parts; whilst that
of the fluid portion deprived of as much free chlorine as could be, by
sulphuric acid and blowing, was 6 parts; and for the evaporated and
crystallized portion, similarly cleared of free chlorine, only 1.5 parts.
16. This result, as compared with the former experiment of a similar kind
(11), shewed, that though reaction of the chlorine on the carbonate had
taken place in the evaporated portion, it was only to a very slight extent,
since the chlorine was almost as much separated from it by the process

altogether, as it had been from the recent preparation by sulphuric acid,
blowing, and heat. The experiment shewed also that there [p090] was a
gradual reaction of the chlorine and alkali in the fluid preparation,
proceeding to a greater extent than in the evaporated portion; for chlorine,
equal to five parts, was found by the nitrate of silver to remain. Hence this
preparation is one which deteriorates even in the small space of forty-three
days. Whether the effect will proceed to any great extent, prolonged
experiments only can shew.
17. From an experiment made upon larger quantities of the Labarraque
liquor, it would appear that the force of crystallization alone is sufficient to
exclude the chlorine. A quantity was put into an evaporating basin, and left
covered over with paper from July 16th to August 28th. Being then
examined, a few large crystals were found covered over with a dense
solution; the whole had the innocuous odour of Labarraque’s fluid, and the
fluid the usual acrid, biting taste. The crystals being separated, one of the
largest and most perfect was chosen, and being well wiped on the exterior,
and pressed between folds of bibulous paper, was rubbed down in water, so
as to make a saturated solution. This had no astringent taste like that of
Labarraque’s fluid, or the mother-liquor, but one purely alkaline; and when
applied to turmeric paper, reddened, but did not bleach it. Equal portions of
this saturated solution and of the mother-liquor were then compared in
bleaching power, acid being added to the former to assist the effect: it was
found, notwithstanding that portions of mother-liquor must have adhered to
1
the crystal, that its solution had not 21 part the power of the mother-liquor.
This, in conjunction with the other experiments, is a striking instance of the
manner in which the carbonate of soda acts, as a simple substance, with the
chlorine in the solution. The crystal itself had never been in contact with the
air: but whether it should be considered as the excess of carbonate of soda
only which crystallized; or whether it is essential to the formation of these
crystals that chlorine should simultaneously be given off into the air; or
what would take place, if the water were abstracted without the evolution of
chlorine, I have not determined.

18. Notwithstanding the perfect manner in which the chlorine may be
thus separated by crystallization and slow evaporation to dryness, yet it is
certain that by quick evaporation a [p091] substance apparently quite dry may
be obtained, which yet possesses strong bleaching power. In one
experiment, where, of two equal portions, one had been evaporated in the
course of twenty-four hours to dryness upon the warm part of a sandbath,
when compared with the former, it had not lost more than one-third of its
bleaching power.
19. With the desire of knowing what effect carbonic acid would have on
Labarraque’s fluid, and whether it possessed in a greater or smaller degree
the power of ordinary acids to expel the chlorine, portions of the solution
were put into two Woulfe’s bottles, and a current of carbonic acid gas
passed through them. The gas was obtained from sulphuric acid and
whitening in a soda-water apparatus, and was well washed in water. The
stream of gas brought away small portions of chlorine with it, but they were
not sensible to the smell, and could only be detected by putting litmus paper
into the current. An immense quantity of gas, equal to nearly 1300 times the
volume of the fluid, was sent through; but yet very little chlorine was
removed, and the bleaching powers of the fluid were but little diminished,
though it no longer appeared alkaline to turmeric paper. Air was then passed
through the solution in large quantity; it also removed chlorine, but
apparently not quite so much as carbonic acid.
20. One other experiment was made upon the degree in which the
carbonate of soda in Labarraque’s liquor resisted decomposition by the
chlorine, even at high temperature. Two equal portions of the fluid were
taken, and one of them boiled rapidly for fifteen minutes; both were then
acted upon by sulphuric acid, blowing, and heat, as described (11), and the
two were then tested by nitrate of silver, to ascertain the quantity of chlorine
remaining: it was nearly three times as much in the boiled as in the unboiled
portion; and by comparing this with the results before obtained (11), it will
be seen that, after boiling for a quarter of an hour, not more than a twentieth
part of the chlorine had acted upon the alkali, to form chloride and chlorate.

21. It would seem as if I were unacquainted with Dr. Granville’s paper
upon this subject, published in the last volume of this Journal, p. 371, were
I to close my remarks without taking [p092] any notice of it. Unfortunately,
Dr. Granville has mistaken M. Labarraque’s direction, and by passing
chlorine, to “complete saturation,” through the carbonate, instead of using
the quantities directed, has failed in obtaining Labarraque’s really curious
and very important liquid; to which, in consequence, not one of his
observations or experiments applies, although the latter are quite correct in
themselves.
Royal Institution, Sept. 3, 1827.

31 See the last volume of this Journal, pp. 211, 460.
32 See Vol. I. of this Journal, p. 461; and Phil. Mag. N. S., I. 376.

H IEROGLYPHICAL F RAGMENTS ; with some Remarks on E NGLISH
G RAMMAR . In a Letter to the Baron William Von H UMBOLDT . By a
Correspondent. ◊

My dear Sir,
I AM happy to tell you that our prospects of new documents from Egypt
are very rapidly increasing: Mr. B URTON has had the good fortune to
discover at length, in a mosque, the triple inscription for which he has been
some years in search; and he has been negotiating with the Pacha for its
removal. From its magnitude and state of preservation, there is every reason
to believe that it will rival the pillar of Rosetta in its importance, and I
sincerely hope that it will tend to check the wildness of conjecture, which
has been rioting without bounds in the regions of Egyptian literature. Mr.
Tattam is printing a Coptic grammar, and I am preparing an Appendix,
which is to contain the rudiments of an Enchorial Lexicon: I ardently wish
that Mr. Burton’s inscriptions may come to my assistance before I complete
it. I have received nothing from France or from Germany for these four

years past: even what is published seems by some fatality to have been
withheld from me; and the booksellers send no answers to my commissions.
I trust your brother will not forget his kind promise to think of me at Berlin.
I have to thank him and you for your obliging present of your Letter to
Abel Remusat on the Genius of the Chinese Language, which has greatly
interested me: the best return that I can make will be to give you some
remarks which have occurred to me on the language of hieroglyphics in
general, [p093] and on the character of the English language, which seems to
approach, in its simplicity, as you have yourself observed, to the natural
structure of the oldest languages, immediately related to the hieroglyphical
form of representation. I fear, however, that I must apologize to you for the
want of method with which I shall be obliged at present to throw my
fragments together: but it may be allowable to make some difference
between a letter and a finished essay.
Hieroglyphics, in their primitive form, are scarcely to be considered in
any case as simply a mode of expressing an oral language: they may be a
direct and independent representation of our thoughts, that is, of
recollections, or sentiments, or intentions, collateral to the representation of
the same thoughts by the language of sounds. We find, in many of the
Egyptian monuments, a double expression of the same sense: first, a simple
picture, for instance, of a votary presenting a vase to a sitting deity; each
characterized by some peculiarity of form, and each distinguished also by a
name written over him; and this may be called a pure hieroglyphical
representation, though it scarcely amounts to a language, any more than the
look of love is a language of a lover. But we universally find that the tablet
is accompanied by a greater variety of characters which certainly do
constitute a language, although we know little or nothing of the sounds of
that language; but its import is, that “such a king offers a vase to the deity;”
and on the other side, that “the deity grants to the king health and strength,
and beauty and riches, and dominion and power.” It is common to see, in
these inscriptions, a number of characters introduced, which are evidently
identical with some of those in the tablets: and however some of them may
occasionally have been employed phonetically, there can be no question of

the nature of the changes which their employment must have gone through
before they assumed the character of sounds: but this is altogether a
separate consideration, and foreign to the present purpose.
Now it is obvious that objects, delineated with the intention of
representing the originals to the eye by their form, must necessarily be
nouns substantive; and that the picture, containing no verb whatever, can
scarcely be said to constitute [p094] either a positive or a negative assertion.
At the same time, it must be allowed that a picture of King George the
Fourth’s coronation, with the date 19 July 1821, could scarcely be
considered otherwise than as asserting a historical truth; and if any emblem
of Truth were attached to it, or if it were deposited among the records of
other historical facts, it would be equivalent to the expression, “George IV.
crowned in July 1821,” which scarcely wants the verb was to convert it into
a positive assertion of a fact.
Strictly speaking, however, there seems to be no direct mode of
supplying the want of the verb is or was in pure hieroglyphical writing; and
if any such sign was employed in the Egyptian or the old Chinese
hieroglyphics, its introduction must have been arbitrary or conventional;
like the employment of a postulate in mathematics. Every other part of a
language appears capable of being reduced, with more or less
circumlocution, to the form of a noun substantive; and the English language
appears to approach to the Chinese in the facility with which all the forms
of grammar may be shaken off.
There is, however, often occasion, in such cases, for a certain degree of
metaphor approaching to poetical latitude; and hence it may happen that the
least literary nations are sometimes the most poetical. It is, in fact,
impossible to exclude metaphor altogether from the most prosaic language;
and it is frequently difficult to say where metaphor ends and strict logical
prose begins; but by degrees the metaphor drops, and the simple figurative
sense is retained. Thus we may say liquid ruby with the same exact meaning
as crimson wine; and yet ruby would never be called an adjective, though
employed merely to express the colour: in coral lips, however, the coral,

first used metaphorically, is converted by habit into an adjective, and the
expression is considered as synonymous with labri corallini.
The general custom in English is to place the figurative substantive, used
as an adjective by comparison, or by abstraction, before the name which
retains its proper sense: thus a chestnut horse is a chestnut like or chestnut
coloured horse; a horse chestnut is a coarse kind of chestnut: and in this
manner we are enabled to use almost every English noun substantive as an
adjective, by an ellipsis of the word like, which, [p095] if inserted entire or
abridged, would make a real adjective of the word, as warlike, friendly. But
this omission of the termination, like other figures of speech, is easily
forgotten in the ordinary forms of language; and the Germans, as well as the
English, make use of almost all their substantives in the place of adjectives,
though they are more in the habit of continuing them into single long
words. When, however, the substantives are so used, they generally become
by abstraction real adjectives: for we seldom think of a chestnut, in
speaking of the colour of a horse; but the idea of a light brown coat, with an
ugly pale-red mane and tail, and a fidgety temper, is very likely to occur to
us: and in a horse chestnut the idea of a horse is out of the question; we only
think of a coarse fruit which a man cannot eat: so that the true sense, in both
these instances, is that of a quality; but coral lips and ivory hands are rather
elliptical expressions, composed of two substantives, which might fairly be
represented hieroglyphically by the assistance of a branch of coral and an
elephant’s tusk. But to describe an abstract quality by any hieroglyphic
character, representative of form only, would be generally impossible:
colours might be imitated, if we supposed coloured figures to be employed;
but other simple ideas, such as those of sound or touch, could never be
immediately presented to the eye; and some circuitous invention would
always be required for their representation.
Horne Tooke has shewn, with considerable felicity of illustration, that all
the parts of speech may be resolved into the noun and the verb; but he has
not pointed out so clearly that every verb may be resolved into a noun and
the single primitive verb is or was, which, in this sense, may be said to be
the only essential verb in any language; as we find, indeed, in the Coptic,

that almost every noun becomes a verb, either by the addition of PE , or
sometimes even without it. Thus, the morning BLUSHES is synonymous with
the morning IS red; he loves justice, with he IS a lover of justice; and I AM
an Englishman, with the person now speaking IS an Englishman. But this
must be understood of is, was, or will be, in all its tenses; the idea of time, if
expressed, being an essential part of the verbal sense.
I confess that some of these reflections have occurred to me in looking
over a very singular work, which I had the curiosity [p096] to take up, in
order to see what kind of information could be possessed by a person
notoriously and professedly ignorant of the origin and relations of the
language which he attempts to teach; and, in short, what kind of light could
be diffused by an apostle of darkness. Blunders, and some of them
ridiculous enough, must, of course, be found in the works of such a person,
but most of them are such as every schoolboy might correct; and there
really is so much of sagacity in some of Mr. Cobbett’s remarks on the errors
of others, that they well deserve the attention of such as are ambitious to
write or speak with perfect accuracy.
I shall not attempt to enter into a regular criticism of this Grammar; I
shall merely make a few miscellaneous observations, as they have occurred
to me in reading it, several of which would be equally applicable to the best
of the existing works of a similar nature.
In Letter III we are told that long and short, though adjectives, do not
express qualities, but merely dimension or duration; from a singular
misconception of the proper sense of the word quality. We find, in Letter
IV, the rule given by most grammarians, though not by all, that the article A
becomes AN, when it is followed by any word beginning with a vowel; but
it is surely more natural to follow the sound than the spelling, and, as we
should never think of saying an youthful bride, it seems equally incorrect to
say an useful piece of furniture; for the initial sound is precisely the same.
In the same manner A unit and A European, seems to sound more agreeable
than AN ; and the best speakers appear to adopt this custom.

Letter VIII gives us a rule for doubling the last letter of a verb in the
participle if an accent is on the last syllable: but it should be observed that
the L is doubled, whether accented or not, as in caballing, travelled,
levelled, cavilled, controlled. The same letter contains a “List of verbs,
which, by some persons, are erroneously deemed irregular,” and which have
been so deemed from the time of our German and Saxon ancestors, though
Mr. Cobbett thinks it would be more philosophical to conjugate them
regularly. Thus we may see at once that freeze may as well give us frozen,
as frieren gives the Germans gefroren; that hang may make hung or hanged,
according [p097] to its sense, as in German we have hienge from hangen, and
hängte from hängen, to execute. For sling and slung, we have authority in
schlingen, geschlungen, for spring and sprung in springen and gesprungen;
for swollen, swam or swum, and swung, in geschwollen, geschwommen, and
geschwungen. And it is quite clear from these examples that “the bad
practice of abbreviating, or shortening,” has nothing to do with the matter.
In Letter XIV we have a very distinct examination of a rule in
punctuation which has been commonly adopted by good printers, without
so distinct a description of its foundation. “Commas are made use of when
phrases, that is to say ‘portions’ of words, are ‘throwed’ into a sentence, and
which are not absolutely necessary to assist in its grammatical
construction.” In a word, two commas are very nearly equivalent to the old
fashioned parenthesis. Again, “the apostrophe ought to be called the mark
not of elision, but of laziness and vulgarity;” a remark made in truly
classical taste, which might have been extended with perfect propriety to
the subject of the next paragraph, the Hyphen, the insertion of which is, to
make it uncertain whether the words united by it are one word or two. He
goes on admirably in the next page. “Notes, like parentheses, are
interrupters, and much more troublesome interrupters, because they
generally tell a much longer story. The employing of them arises, in almost
all cases, from confusion in the mind of the writer. He finds the matter too
much for him. He has not the talent to work it all up into one lucid whole;
and, therefore, he puts part of it into Notes” . . . . . “Instead of the word and,
you often see people put &. For what reason I should like to know. But to

this & is sometimes added a c; thus, &c. And is, in Latin, et, and c is the
first letter of the Latin word caetera, which means the like, or so on. This
abbreviation of a foreign word is a most convenient thing for such writers
as have too much indolence or too little sense to say fully and clearly what
they ought to say. If you mean to say and the like, or, and so on, why not
say it? . . . The abbreviation is very frequently made use of without the
writer having any idea of its import.” But it is surely a mischievous maxim,
never to “think of mending what you write. Let it go. No [p098] patching; no
after painting.” On the other hand he is right in protesting “against the use
of what, by some, is called the dash. Who is to know what is intended by
the use of these dashes? . . . . It is a cover for ignorance as to the use of
points; and it can answer no other purpose.”
In Letter XV, there is a singular conceit with regard to the keeping up a
distinction between a and an, where it is insisted that we must not say “a
dog, cat, owl, and sparrow,” because owl requires an; “and that it should be,
a dog, a cat, an owl, and a sparrow;” which is certainly better, and would be
so, even if there were no owl in the question.
Letter XVII. The criticism on Milton’s “than whom none higher sat,” is
perfectly correct. Than is never a preposition, and is simply a variation from
the older then, both in English and in German. John is better than James
means simply John is good first, then James: er is eher or e’er. Who would
sound awkwardly, but would be more grammatical.
Letter XIX gives a definition of the ellipsis, which would be a lesson to
Apollonius himself: the compasses, it seems, “do not take their sweep all
round, but leave out parts of the area or surface.” The objection to
Blackstone’s language is very questionable. “The very scheme and model
WAS settled,” may, perhaps, be defended, because scheme and model are
considered as one thing, the words being intended to illustrate each other,
but not to point out different attributes of the administration of justice; and
both words may be admitted, as a collective term, to govern a singular
rather than a plural verb. It seems also to be an error to make with a
conjunction rather than a preposition, and to say “The bag, with the guineas
and dollars in it were stolen,” or “zeal, with discretion, do much.” “I

expected to have seen,” is justly noticed as a common error for “I expected
to see.” The meaning of an active verb is erroneously confounded with that
of a transitive verb, in the remarks on the word elope, which means to go
off, or to run off, and we should naturally say was gone off, but had run off.
The nature of the subjunctive mood is dismissed in the same Letter
without better success than has been obtained by former grammarians. An
essay was published about thirty years ago in a periodical work, which
brings the subject into a small compass; [p099] suggesting that the
subjunctive mood ought always to be considered as a conditional future.
The examples given are, “If the Elbe is now open, we shall soon have the
mails, and then, if there be any news from the army, I will send it you
immediately.” “If Catiline was generous, it was in order to serve his
ambition.” The subjunctive past, if I were, becomes present, by being the
future of the past; going back to the time when the present was future, and
therefore contingent; and this conditional sense involves no difficulty,
except when a mistaken adherence to the fancied rules of grammar forces it
in where it has no business: thus the rules of some grammarians would lead
us to say, if Catiline were ambitious; which is totally contrary to the true
sense of the subjunctive. Mr. Cobbett seems to have some such distinctions
in view when he says that “if has nothing at all to do with the government
of the verb. It is the sense which governs.” By this he means that if does not
require a subjunctive unless is relates to a future contingency. He is right in
saying “Though her chastity is becoming, it gives her no claim to praise”:
but most decidedly wrong in adding “she would be criminal if she was not
chaste”; for was is here used as relating to the present circumstances, which
are the future of the past, and therefore require the subjunctive were to
denote the condition intended. He has, however, done signal justice to the
cause of this injured verb, by introducing it for was, in his sixth lesson,
where he says it should have been “Your Lordship were apprized of every
important circumstance.”
Such errors as this, however, are easily corrected, and many of the acute
remarks which have been here copied are well worthy the attention of
practical grammarians; at the same time enough has been said, without any

disparagement of Cobbett’s talents, to show that a man cannot be well
qualified to teach that which he has not had the means of properly learning.
For although the English language appears at first sight to be extremely
simple and philosophical in its structure, it has, in fact, been derived from a
variety of heterogeneous sources; it has undergone a variety of vicissitudes,
and has served for the expression of a multiplicity of discussions on the
most refined subjects in literature and history and science, for [p100] the
feelings of oratory, and the passions of poetry, and it has been worn away
by degrees, as the crystal in the stream is worn to a pebble, till it has
returned to a simplicity which wears the aspect of the immediate offspring
of the Chinese or Egyptian or Mexican Hieroglyphics. But with all this, it
has still some spots, some idioms, which invariable custom obliges us to
retain; and which can only be distinguished from corruptions and
vulgarisms by tracing their history through the different stages of its
progress, including, of necessity, the corresponding idioms in the parent
languages out of which it has arisen.
Believe me always, my dear Sir,
Your’s very sincerely,
****

Malaria: an Essay on the Production and Propagation of this Poison, and
of the Nature and Localities of the Places by which it is produced, with
an Enumeration of the Diseases caused by it, and of the Means of
diminishing and preventing them, both at Home and in the Naval and
Military Service. By J. Mac Culloch, M.D., F.R.S., &c. &c. Longman and
Co. 1827. ◊

T HOUGH we have given a place in our Journal to two articles on Malaria
from Dr. Mac Culloch, we have thought it expedient to take some notice of
his book under the form of a review; particularly as some matters have
come under our cognizance, which may add some illustrations to this
subject where the author appears to have been in a state of deficient

information, or to have shunned the question for reasons which appear to us
somewhat over refined.
We allude principally here to the localities and the facts, as they are now
before us; circumstances and events which seem to us of the greatest
importance, as enforcing the value of the details which he has collected, and
as holding out warnings to the people respecting the preservation of their
healths, in addition to those which the work before us has given in
describing the soils or characters of ground in England from which this
destructive poison is generated. And before we proceed to the analysis of
his book, we shall state what those are, or at least a few of them, while
wondering that he should have overlooked them, or regretting that any
fancies should have prevented him from stating what would have been of so
much utility. [p101]
It is notorious that, in the last autumn, the remittent fevers in various
parts of the country amounted to a species of pestilence, such as has
scarcely been known in England from this cause, or we might almost indeed
say, from any other disease since the days of Sydenham. Wherever ague had
ever existed, or even been supposed possible, in those places was this fever
found: so that in all the well-known tracts in Lincolnshire, Norfolk, Suffolk,
Kent, Essex, Sussex, Hampshire, and so forth, there was scarcely a house
without one or more inhabitants under fever, while the event, as might be
suspected, was a considerable mortality. In the parish of Marston, in
Lincolnshire, for example, it amounted to 25 in 300 inhabitants; in some
other places, it reached one in sixteen, one in thirteen, one in nine. And so
extensive was its range, that even Hastings did not escape; while it should
be almost superfluous to say that every other town on the sea-coast was so
much infested by it, that they who resorted to them for bathing, as usual,
found themselves most awkwardly situated, and also suffered in
considerable numbers.
To come nearer home, and to what must interest us of the metropolis
more, the same fevers were extremely abundant in various parts of the
outskirts of London, as also in the villages or towns which are connected
with it, within a range of from six to ten miles. Not to enumerate all these,

this was the case throughout the range of streets or houses which extends
from Buckingham Gate to Chelsea; in which long line, it is said, that almost
every house had a patient or more under this fever; though, as the author
has truly observed, these were mistaken for typhus, or at least thus
misnamed. Thus it was also about Vauxhall and Lambeth; and to a great
extent among all that scattered mixture of town and country which follows
from Whitechapel, from Bishopsgate, and so forth, and very particularly
along Ratcliffe Highway, and so on, to an indefinite range along the river,
not only on this side but on the opposite one, so as to include Rotherhithe,
and then proceeding onward to Deptford, Greenwich, Woolwich,
Plumstead, so as to carry us beyond the boundary which we proposed to
notice.
And in addition to the towns or villages which we have just named, we
may enumerate Lewisham, in which we knew one house in which there
were nine patients under this fever, which proved mortal to one. Dulwich,
especially subject to this disorder, Fulham, Ealing, and the several other
villages along the Thames, as far as Chertsey; and even Richmond, [p102]
where, as at Lewisham, there was one house known to us, inasmuch as
being intimate friends, where ten individuals at one time were suffering
under this disease.
We must not prolong this enumeration, since we might easily occupy a
dozen of our pages with similar details, ranging, in fact, all over England;
but we must still observe, that whatever was the pestilence last year, it
promises to be much greater in the present one. This is easily judged from
the manner in which the season has set in; but still more decidedly from the
extraordinary prevalence of ague in the spring; since that which is
intermittent fever then, will be remittent in the autumn, or rather, as the
author has justly remarked, there will scarcely be a definite season of vernal
intermittent, but the remittent will commence immediately, increasing in
extent and severity as the summer advances, and promising to become, in
the autumn, the greatest season of disease that England has known for this
century.

As an example of this, it must suffice to enumerate two or three facts,
while these are as satisfactory for our purpose as a thousand would be. The
most general of these is, that ague is at this moment extremely abundant
where it was formerly so little known as not to be noticed, and that where
single cases used to occur, there are now hundreds. Thus has it prevailed at
Fulham and Ealing, and in the outskirts of London, and even in the town
itself; and thus does it so prevail at Greenwich, Deptford, and in the
associated vicinity, that a medical friend informs us, that it comprises more
than two-thirds of his entire practice, which is very extensive; whereas a
few years ago he had rarely a patient in a year. Thus also in the Military
Hospital at Woolwich, there were in the spring three hundred patients with
this disease; while in former times, we are assured, that an ague was
scarcely known once in five or six years.
These are a few of the facts within our knowledge, but not one in a
thousand, which evince the necessity of the publication before us; a book
which seems to have been singularly well-timed, in as far as its purpose is,
by a dissection of the sources of malaria, to diminish the ravages of both
these kinds of fevers. And in this view we consider it a work of very
considerable utility, inasmuch as it points out all the needful circumstances,
as to prevention, in great detail; while these seemed particularly called for
in England, from the entire and not less singular neglect which this subject
has experienced, not only from the people at large, but from the medical
profession. Beyond this, all that we need say of [p103] the character of the
work is, that it contains the only regular and complete attempt at the natural
history of Malaria that has been executed; since the several foreign writings
on this subject are partial, or imperfect, or local in their investigations; and
having said thus much, we shall proceed to give a brief analysis of its form
and matter. And this analysis may be truly brief, without inconvenience;
since the two Essays from the pen of the author, to which we have given a
place in our Journal, will supersede the necessity of making that useful and
practical abstract which we should otherwise have felt ourselves bound to
give.

To pass over an introductory chapter of the usual necessity, the author
commences by pointing out the several disorders, in a general way, which
are produced by malaria, for the purpose of proving the sources of this
poison; and as we are of those who take the facts as already proved, we
need not notice it further.
The third chapter details the characters of those soils or situations which
are most commonly or generally admitted to produce this poison: and
though it contains some facts not very universally known, we shall also pass
it over as of less moment than that which follows.
This is the fourth chapter, containing the details of the circumstances
producing malaria, which have been either denied or overlooked; and it is
one of the most important practical chapters in the book, inasmuch as it is to
the popular ignorance of these that we must attribute a large proportion of
the cases of fever occurring in common life. These, therefore, we shall mark
briefly; and even the briefest notice will be of use in the way of precaution,
while we must refer to the book itself for those proofs of the truth of the
several views, which we could not take room to give. Generally, however,
we may state this leading argument of the author, because it is brief, and, to
us, appears satisfactory. It is this: that as the quantity of the poison which
any person can inspire is necessarily small, and as this small quantity can be
produced by a small marshy spot as well as a large one, it is the same as to
the production of disease, whether the marsh is a foot square or a mile,
provided the exposure be complete: while also, any piece of ground where
vegetables decompose under the action of water, is virtually a marsh, or
must produce malaria.
This enumeration, therefore, under that view, comprises, in addition to
marshes, whether fresh or salt, all the cases where water is present in such a
manner as to act upon vegetables; and the chief are the following. [p104]
It is shown, and by facts, that the rushy swamps of high moorlands,
however small the extent, do produce this disease; and we must not here
forget to name what, however, belongs to the preceding chapter, woods and
coppices, little suspected in England, yet shown to be the cause of fevers in
Wales, and also in Sussex; very probably, every where else. It is also shown

that meadows and moist pastures, whether in flat lands or on elevations,
generate fevers; and very particularly, should they have been affected by
inundation or unusual moisture, and if that should be followed by heat. And
while it is also specifically shown how, in all cases, it is the produce of the
drains or ditches required in meadow lands, it is distinctly proved that, even
without these, malaria is produced, or that it is generated by the meadow or
moist pasture itself.
It is also shown that this poison is produced by rivers, by all flat rivers at
least, or those of which the progress is slow and through meadow lands;
while this is pointed out as one of the causes, especially, which is not
suspected or not believed in England. And here we can add a fact to our
author’s statement, which is decisive: this is the case of the barracks at
Morne Bruce, in Dominica, situated on a steep and rocky hill, perfectly dry,
and free from all other causes of suspicion, while eternally subject to the
most severe fevers. And the cause is, a mountain stream, about 300 yards
below this building, in the valley, always covered by a mist in the evenings,
and ascertained, by direct experience, to be the very cause of the diseases in
question.
Our author also notices canals, mill-ponds, ornamental waters, and all
other pools and ponds, even to so small a dimension as those formed in
gravel-pits; pointing out those, in particular, as common causes of fever
about London, and apparently much inclined to pass a very severe judgment
on the canal in St. James’s Park, and also on the pond in St. James’s Square,
while apparently restrained by his prudential reasons, which appear to us
sufficiently misplaced, or, as we should fairly call them, somewhat absurd.
But as we must not affront a writer whose papers we have admitted, we
shall say no more on this matter. In noticing drains, he also speaks of moats
and modern fortifications; attempting to show that the fevers so common in
the sieges of ancient castles were produced by their moats, and noticing the
familiar fact of the frequency of fevers in fortified towns. Lakes also are
pointed out as situations generating this poison: and it is here especially
noticed that if, in those and other cases, malaria is produced by the
vegetable growth and decomposition, [p105] so is it the consequence of the

exposure of the mud of such receptacles of water; a cause which is again
treated of at greater length in the subsequent chapter.
This chapter relates to what the author calls obscure and disputed cases.
We shall pass over these, which, as not implying precautionary measures,
are of the least interest, and commence by noticing the case of vegetable
putrefaction. It is attempted to show, that the vegetable need not be living to
produce malaria, but that, even if utterly decomposed, its elements, acting
on water, can generate this poison. Among the cases under this head, are
flax and hemp ponds, common sewers and drains, dunghills, and tide
harbours; and the evidences under each are sufficient to make good the
assertion. But the most important of all, in our view at least, is bilge-water:
since our author has pretty clearly shown that all the fevers of ships
(excepting, of course, a few casual instances of contagion) arise from this
cause, and that if ships were kept clean, fever or sickness would be nearly
unknown at sea. This we do indeed conceive one of the most important
points in the work before us; and if the author has referred to Sir Henry
Baynton, as a stranger, we can quote him, as a friend, that warrants for all
that is here asserted, and for far more; since his collection of facts on this
subject is most important, and we think him almost culpable in not having
long ago given them to the public. If the Leviathan was always the
healthiest ship in the navy; if she even left the West Indies, after a long
anchorage and service, with a crew of 500 men, and not one sick, it is a case
in the navy which never occurred before, nor since, and which arose
entirely from the knowledge of this able and careful officer respecting the
subject that we are discussing.
A sixth chapter explains, under the head of revolutions in the production
of malaria, a variety of circumstances not easily admitting of abridgment.
The chief of these are, the effects produced by drainages, and reversely,
those which arise from inundations or other incidental causes affecting the
state of the soil. But the most important view which it contains is that which
relates to the effect of embankment in rivers, and to the geological changes
produced by the distribution of alluvia. As, however, we cannot well state

this in a small space, we shall pass to the chapter on the Propagation of
Malaria.
This is the largest, and, as it strikes us, the most interesting of the whole;
while the author has made it the depository of a variety of remarks and
recommendations on this [p106] subject, very particularly as it relates to the
army. If he is correct,—and we see no reason to doubt it, from the nature of
the statements,—the ignorance of this subject, even among the medical
department of the army, has been most extraordinary and most
unaccountable; while if Walcheren is proof enough of this, the writer before
us has pointed out facts enough to show that it was not a solitary case, while
evidently restrained by fear of some sort—we are almost inclined to call it
cowardice—from telling all that he might have told. And we do think it
wrong to retain or suppress that which is important to the public safety,
under a fear that the feelings of individuals may be hurt; since the business
of a writer is with justice and utility, and the security or welfare of
thousands is of infinitely greater moment than the comforts of a few, and
those also culpable.
Under this head, propagation, the author describes how this poison is
conveyed by the winds, while the facts add much to the number and variety
of the precautionary measures. And here also we find a speculation of no
small curiosity, respecting the East wind, attempting to prove that wherever
this is insalubrious or pernicious, it arises from its being the vehicle of
malaria; while attempting also to prove that this substance can be conveyed
from Holland to the coasts of England in that wind. We shall not pretend to
give an opinion on this subject; and since the author himself has noticed it
in the paper printed in our present number, we shall suffer our readers to
form their own judgments respecting it.
One also of the most curious facts mentioned in this chapter, is the
singular limitation of malaria; and we must admit that the instance quoted
as to the Chatham road is so remarkable as to be almost incredible; though,
as we find that all the people agree in it, we cannot pretend to say it is not a
fact. Indeed the facts of this nature, so familiar at Rome, are fully as
inexplicable; so that all we can conclude is, that we are ignorant of the

philosophy of this subject: no very great cause of surprise, unless it were
proved that we could explain every thing else which belongs to
meteorology.
In the eighth chapter we have an explanation of the effects of climate and
seasons in the production of malaria; and while we need not analyse the
facts which it contains, we may introduce in lieu of this, the explanations
which its statements afford as to that recent increase of the diseases of
malaria which we noticed at the commencement of this article. The last few
years have been distinguished for an [p107] uncommon prevalence of East
winds, and to such a degree indeed, that we can find no meteorological
records at all to be compared with the history of these years. And while the
history of the intermittent and remittent, in London at least, from the time of
Morton and Sydenham downwards, shows that all its periods of such
diseases have been periods of East winds, it is not difficult to see how it acts
as to both classes of marsh fever. To London, in particular, it is the best
conductor, propagating the malaria from all the moist lands to the eastward.
To the East coast, if our author’s theory is valid, it brings the malaria from
Holland; and, moreover, as it forms our hottest summers, it causes our own
climate to approximate more to the southern ones, and thus enables our
lands to produce a greater quantity of malaria than in ordinary summers.
To pass from the eighth chapter, the ninth is a partial sketch of the
geography of malaria; a chapter for which the author apologises, but which
is nevertheless a very interesting collection of facts on a subject where a
volume is, doubtless, a desideratum. And it would require a volume; while,
in spite of our author’s fears, we can really see no reason why such a
statistical account of health should not be drawn up for England, when the
utility of it is unquestionable. It is true that people cannot abandon their
homes or change their residences, because their lots happen to be cast in an
insalubrious country. But it is not less important to know what and where
these dangers are; because, though the inhabitants may be compelled to
abide, they can still correct much of the evil by the various modes pointed
out, or avoid much of the hazard by resorting to the obvious precautions. To
be ignorant, is to be exposed to the full evil: to know where it lies, is to

know how and where to avoid it in numerous ways; since it will be found
that by far the greater number of diseases occurring, were not necessary or
unavoidable, but have been the result of ignorance as to the precise fact or
spot which did produce the effect in question. And this we conceive to be
the great use of the book before us; and that if ever it, or a code of rules
founded on it, shall become popular, or form a vade mecum, particularly in
the country, the effect will be to reduce most materially the quantity of
disease, and very particularly that which is by far the most serious, the
summer and autumnal fevers. On this around, we should be glad to see a
geography of malaria for England; and we do hope that it will be
undertaken by some person of sufficient industry, and of more [p108] courage
than our author; while we cannot doubt that whoever attempts it would at
least find it a profitable speculation. With these remarks we must pass over
this chapter, as we could take no statement from it which would serve any
useful purpose; though, as far as it goes, it will form a very useful guide to
travellers on the continent of Europe, or to those who, as emigrants, are in
search of a residence abroad.
The tenth chapter examines the inquiries which have been instituted into
the chemical nature of malaria, leaving the question just where it was. In
fact we, as chemists, do not believe that this science is yet in possession of
the means required for analyses of this delicate nature; but we see no reason
whatever why it should be despaired of, when chemistry has already, within
a very few years, effected things which seemed far more impracticable and
hopeless.
The eleventh and last chapter contains an enumeration of the diseases
produced by malaria, presenting a most formidable list, and absolutely
making us shudder in some of the details which relate to the worst parts of
France and Italy. The representation here given of the average of life in
these districts is particularly striking; while of the truth of all the facts, we
can speak from personal knowledge. Our author has also noticed the effect
of this poison on animals; showing that it is the cause of the noted
epidemics in cattle, and also of the rot in sheep. If he will look into Livy, he
will find a confirmation, which he appears to have passed by when quoting

that author for epidemic seasons: this being, that in the same years in which
epidemic “pestilences” appeared among the people, there was also a great
mortality among the cattle.
We do not know what his own profession will say of his attempt, or
rather proposal, to prove that the celebrated disease of the nerves called Tic
Douleureux is the produce of malaria and a mode of intermittent fever; nor
how they will receive his proposal to arrange Sciatica and Rheumatic pains,
with many other local diseases, under this head. But this is not our affair:
and as he has promised us two other volumes, on all the diseases which are
produced by malaria, including these, we must wait with patience; knowing
at least that he is a dealer in facts and not in hypotheses, and expecting, that
even if he should fail to establish his point, he will try to do it, as he has
been used to do in the other sciences which he has attempted, through the
road of facts and evidence. [p109]

An Account of a new Genus of Plants called R EEVESIA . By John Lindley,
Esq., F.L.S., &c. &c. ◊

I N a collection of dried specimens of plants sent to the Horticultural Society
from China, by Mr. Reeves, are a few branches, with flowers, of a
remarkable genus which is at present undescribed, but which is of so
curious a nature, and of such importance with reference to the
determination of some natural affinities, that I have thought it deserving
immediate record; especially as drawings of the fruit, which have been
subsequently obtained from the same indefatigable correspondent of the
Society, render its history tolerably complete.
The branches appear to be fragments of an evergreen tree; they are
slender, rounded, and smooth. The nascent gemmæ are covered with a
dense rufous pubescence. The leaves are alternate, becoming, towards the
extremities of the branches, opposite by approximation; their form is ovate-
lanceolate acuminate, and in size they vary from three inches to nearly six
in length; the surface, even of the youngest, is perfectly smooth on each

side; their veins are inconspicuous, the lowest pair of venæ primariæ being
divergent at an angle of about 40°, while the others spread outwards at an
angle of 55° or 60°; the venæ arcuatæ and externæ are obscurely seen, but
form together a number of rhomboidal spaces, equal in diameter to nearly
one third of each side of the leaf; the proportion borne by the petiole to the
lamina is variable, sometimes equalling one-fourth of the length of the
latter, and not unfrequently being less than one-sixth of its length: this
proportion not depending upon the station of the leaves; the petiole is
smooth, half-round, and thickened at the extremity, where it unites with the
lamina. Stipulæ are none. The flowers are greenish-white, in terminal
thyrsoid compound racemes; the upper part of the rachis, and of its
branches, is slightly protected by stellate pubescence; the pedicles are
closely covered with pubescence of the same nature, and have one subulate
downy deciduous bracteola at the base, and another towards the apex. The
calyx is inferior, campanulate, tapering a little towards the base, densely
clothed with stellate pubescence, bursting irregularly at the apex into [p110]
four or five ovate teeth, which are somewhat imbricated during æstivation,
but which are separated by the growth of the petals long before the
expansion of the flower; the veins of the calyx are remarkably reticulated,
and when cut, a considerable quantity of mucilaginous viscid fluid is
exuded. The petals are whitish-green, hypogynous, with a convolute
æstivation; their ungues are spatulate, and as long as the calyx; their laminæ
oblong, spreading flat, and then overlapping each other at the base; at the
point of separation of the unguis and lamina is a small callus, and on each
side a notch upon the margin. The stamens are seated upon a long, filiform,
subclavate, smooth torus; the filaments are consolidated into a capitate five-
toothed cup, nearly closed at the orifice, and on the outside of this cup are
placed the antheræ, three to each tooth; the latter are two-celled, with
divaricating cells, which open longitudinally, and are so entangled with
each other that the whole surface of the cup appears, when the antheræ have
burst, to consist of a single many-celled anthera. The pollen is spherical and
smooth. he ovarium is seated within the cup of stamens, and is so entirely
concealed that it cannot be discovered till some part of the cup is removed

by violence; it is ovate, smooth, and formed of five inseparable cells, each
of which has two ovula placed one above the other, and attached to their
placenta by their inner margin; the stigma is sessile, with five radiating
lobes. From the Chinese drawing, the half-ripe fruit appears to be fleshy,
with five deep angles, and five cells, without any remains of calyx, and with
a slight appearance of separation between the lobes. The ripe fruit is an
obovate, five-angled, five-celled, five-valved, retuse, woody capsule, with a
loculicidal dehiscence, and no separable axis. The seeds are attached one to
each side of the valves, and are expanded at their lower end into a wing.
From this description it is obvious that, with the single exception of the
contents of the seed, we are in possession of all that it is essential to know
of the structure of this plant. The next subject of consideration is its affinity.
The stellate pubescence, the thickening of the petiole at the point where it
expands into the lamina, the station of the stamens upon a long, filiform
torus, the external position of the [p111] antheræ, and the union of the
filaments by threes into a cup surrounding the ovarium, are all characters
that forcibly call to recollection the genus Sterculia. The calyx, indeed, in
that genus is generally divided much more deeply than in the plant now
under consideration, and the antheræ are usually seated at the base of the
ovarium; but, on the other hand, in Sterculia colorata of Roxburgh, which, if
a distinct genus, (E RYTHROPSIS ) as I am inclined to believe; is nevertheless
next of kin to Sterculia, the calyx is of the same figure and divided in the
same degree, and the antheræ are also combined in a capitate cup inclosing
the ovarium. If, however, we pursue this comparison further we find that,
with the characters now adverted to, the similarity ceases; in Sterculia there
are no petals, the calyx has a valvular not imbricate æstivation, the cells of
the fruit separate into distinct folliculi, and do not combine into a solid
woody capsule, and the seeds are destitute of wings.
The fruit suggests so obviously some affinity with Pterospermum, that it
is next necessary to institute a comparison with that genus. Stellate
pubescence, a calyx divided into five portions, five hypogynous unguiculate
petals, and fifteen fertile stamens united into a cup, seated on a stipitiform
torus, and surrounding the ovarium, a five-celled ovarium, a woody five-

celled capsule, with a loculicidal dehiscence, no axis, and winged seeds; all
these characters are common to Pterospermum and our plant; but on the
other hand the points in which they differ are of much importance. The
æstivation of Pterospermum is valvate recurved not imbricate; its calyx is
five-parted, not four—five-toothed; its anthers have parallel not divaricating
cells, and are seated upon long distinct filaments, not sessile, upon the
outside of a capituliform cup; and finally the petioles of the leaves are not
connected with the lamina by a thickened space. The seeds are also winged
at the apex, not at the base, but upon this point it is not my wish to insist.
If the comparison thus instituted with Pterospermum and Sterculia be
attentively considered, we cannot fail to remark that the subject of these
observations is nearly equally related to both; to Pterospermum in its petals
and fruit, to Sterculia in its calyx and stamens. It must, therefore, be
stationed between those two genera, thus confirming the propriety of M.
[p112] Kunth’s combination of the Sterculiaceæ of Ventenat with the
Byttneriaceæ of Mr. Brown; and, in fact, breaking down every barrier
between them.
There are many other points that will suggest themselves to the Botanist,
in which this plant is highly worthy of consideration, but for the present it
will be enough to give the botanical characters with which it may stand
recorded. It is named in honour of John Reeves, Esq., now resident at
Canton, to whom we are indebted for our knowledge of it, from whose
unwearied exertions in the cause of science the botany of China has
received material assistance, and to whom our gardens are indebted for
many of the fairest ornaments they contain.
REEVESIA.
Ord. Nat. B YTTNERIACEÆ ; Sterculiam (Erythropsin) inter et
terospermum.
Calyx campanulatus, 5-dentatus, æstivatione imbricatâ, pube stellatâ tomentosus, bracteolatus.
Petala 5, hypogyna, unguiculata, æstivatione convoluta, callo inter unguem et laminam. Stamina in
toro longo filiformi insidentia. Antheræ 15, sessiles, in cyatho capituliformi, apice tantum pervio,
obsoletè 5-dentato connatæ, extrorsæ, biloculares, loculis divaricatis intricatis, longitudinaliter
dehiscentibus. Pollen sphæricum glabrum. Ovarium sessile, intrà cyathum antheriferum, ovatum,
glabrum, 5-angulare, 5-loculare, loculis dispermis. Ovula margini loculorum unum super alterum

affixa, superiore basi concavo in inferiorem incumbente. Stigma 5-lobum, simplicissimum, sessile.
Capsula stipitata, lignosa, obovata, 5-angularis, 5-locularis, loculicidò 5-valvis, axi nullo. Semina
cuique loculo duo basi alata.——Arbor (Chinæ) foliis alternis exstipulatis, racemis terminalibus
compositis, floribus albis.

1. Reevesia thyrsoidea.
Habitat in China (v. s. sp. in Herb. et iconem in Bibliotheca Soc. Hort.)

[p113]

ASTRONOMICAL AND NAUTICAL COLLECTIONS.

i. Elementary View of the U NDULATORY Theory of L IGHT . By Mr. F RESNEL
.◊
[Continued from the last Number.]

I SHALL not undertake to explain here in detail the reasons and the
calculations which lead to the general formulas that I have employed to
determine the position of the fringes and the intensity of the inflected rays:
but I think it right to give at least a distinct idea of the principles on which
this theory rests, and particularly of the principle of interference, which
explains the mutual action of the rays of light on each other. The name of
interference was given by Dr. Y OUNG to the law which he discovered, and
of which he has made so many ingenious applications.
This singular phenomenon, so difficult to be satisfactorily explained in
the system of emanation, is on the contrary so natural a consequence of the
theory of undulation, that it might have been predicted from a general
consideration of the principles of that theory. Every body must have
observed, in throwing stones into a pond, that, when two groups of waves
cross each other on its surface, there are points at which the water remains
immoveable, when the two systems are nearly of the same magnitude, while
there are other places in which the force of the waves is augmented by their
concurrence. The reason of this is easily understood. The undulatory motion
of the surface of the water consists of vertical motions, which alternately

raise and depress the particles of the fluid. Now, in consequence of the
intersection of the waves, it happens, that at certain points of their meeting,
one of the two waves has an ascending motion belonging to it, while the
other tends at the same instant to depress the surface of the liquid:
consequently, when the two opposite impulses are equal, it can neither be
actuated by one nor the other, but must remain at rest. On the contrary, at
the points in which the motions agree in their direction, and conspire with
each other, the liquid, urged in the same direction [p114] by each of the
forces, is raised or depressed with a velocity equal to the sum of the effects
of the two separate impulses, or to the double of either of them taken singly,
since they are now supposed to be equal. Between these points of perfect
agreement and complete opposition, which exhibit, one the total absence of
motion, the other the maximum of oscillation, there are an infinity of
intermediate points, at which the alternate motion takes place with more or
less of energy, accordingly as they approach more or less to the places of
perfect agreement, or of complete opposition of the two systems of motion
which are thus combined, or superinduced on each other.
The waves which are propagated in the interior of an elastic fluid, though
very different in their nature from those of a liquid like water, produce
mechanical effects by their interference, which are exactly of the same kind,
since they consist in alternate oscillatory motions of the particles of the
fluid. In fact, it is sufficient that these motions should be oscillatory, that is,
that the particles should be carried by them alternately in opposite
directions, in order that the effects of one series of waves may be destroyed
by those of another series of equal intensity; for, provided that the
difference of the route of the two groups of waves [derived from the same
origin] be such, that for each point of the fluid the motions in one direction,
belonging to the first series, correspond to the motions, belonging to the
second, in the opposite direction, they must perfectly neutralise each other,
if their intensity is equal: and the particles of the fluid must remain in
repose. This result will always hold good, whatever may happen to be the
direction of the oscillatory motion, with regard to that in which the
undulations are propagated; provided that the direction of the oscillatory

motion be the same in the two series to be combined. In the waves which
are formed on the surface of a liquid, for example, the direction of the
oscillation is [principally] vertical, while the waves are propagated
horizontally, and consequently in a direction perpendicular to the former; in
the undulations of sound, on the contrary, the oscillatory motion is parallel
to the direction of the propagation of the sound, [or rather is [p115] identical
with it]; and these undulations, as well as the waves of water, are subject to
the laws of interference.
The undulations formed in the interior of a fluid have here been
mentioned in a general manner: in order to form a distinct idea of this mode
of propagation, it must be remarked, that when the fluid has the same
density and the same elasticity in every direction, the agitation produced in
any point must be propagated on all sides with the same velocity: for this
velocity of propagation, which must not be confounded with the absolute
velocity of the particles, depends only on the density and elasticity of the
fluid. It follows thence that all the points, agitated at the same instant in a
similar manner, must be found in a spherical surface, having for its centre
the point which is the origin of the agitation: so that these undulations are
spherical, while the waves, which are seen on the surface of a liquid, are
simply circular.
We give the name of rays to the right lines drawn from the centre of
agitation to the different points of this spherical surface; and these rays are
the directions in which the motion is propagated. This is the meaning of the
term sonorous rays in acustics, and of luminous rays or rays of light in the
system which attributes the phenomena of light to the vibrations of a
universal fluid, to which the name of ether has been given.
The nature of the different elementary motions, of which each wave is
composed, depends on the nature of the different motions which constitute
the primitive agitation. The simplest hypothesis that can be entertained
concerning the formation of the luminous undulations, is, that the small
oscillations of the particles of the bodies, which produce them, are
analogous to those of a pendulum removed but little from its point of rest;
for we must conceive the particles of bodies, not as immoveably fixed in

the positions which they occupy, but as suspended by forces which form an
equilibrium in all directions. Now, whatever the nature of such forces may
be, as long as the displacement of the particles is but small in proportion to
the extent of their sphere of action, the accelerating force which tends to
restore them to their natural position, and which thus causes them to
oscillate on each side of it, may always, without sensible error, be
considered as proportional [p116] to the magnitude of that displacement: so
that the law of their motion must be the same as that of the motion of the
pendulum, and of all small oscillations in general. This hypothesis, which is
suggested by the analogy with other natural phenomena, and which is the
simplest that can be formed respecting the vibrations of the luminous
particles, may be considered as experimentally confirmed by the
observation, that the optical properties of light are all independent of any
circumstances which cause the greatest difference in the intensity of the
vibrations: so that the law of their motion must be presumed to be the same
for the greatest as for the smallest.
It follows from this hypothesis respecting the small oscillations, that the
velocity of the vibrating particle at each instant is proportional to the sine of
an arc, representing the time elapsed from the beginning of the motion,
taking the circumference for the whole time required for the return of the
particle to the same point, that is, the time occupied by two oscillations, the
one forwards and the other backwards. Such is the law according to which I
have calculated the formulas which serve to determine the effect of any
number of systems of waves of which the intensities and the relative
positions are given. These formulas will be found in the Annals of
Chemistry, vol. xi., page 254: [they may be applied with security to the
phenomena there considered, though the perfect accuracy of the hypothesis
in all possible cases may be questioned, upon the grounds of the
microscopical observations on the motions of vibrating chords, published
by Dr. Young in the Philosophical Transactions for 1800. T R. ] Without
entering into the details of the calculations, I think it necessary to show in
what manner the nature of the undulation depends on the kind of motion of
the vibrating particles.

Let us suppose, in the fluid, a little solid plane which is removed from its
primitive position, towards which it is urged by a force proportional to the
distance. At the beginning of its motion, the accelerative force produces in
it an infinitely small velocity only; but its action continuing, the effects
become accumulated, and the velocity of the solid plane goes on
continually to increase, until the moment of its arrival at [p117] the position
of equilibrium, in which it would remain, but for the velocity which it has
acquired; and it is by this velocity only, that it is carried beyond the point of
equilibrium. The same force which tends towards this point, and which now
begins to act in a contrary direction, continually diminishes the velocity,
until it is completely annihilated; and then the force continuing its action
produces a velocity in the contrary direction, which brings the plane back to
its place of equilibrium. This velocity again is very small at the
commencement of the return of the particle, or plane, and increases by the
same degrees as it had before diminished, until the instant of the arrival of
the particle at the neutral point, which it passes with the velocity previously
acquired: but when it has passed this point, the motion is diminished more
and more by the effect of the force tending towards it, and its velocity is
reduced to nothing when it arrives at the place of the commencement of the
motion. It then recommences, at similar periods, the series of motions
which have been described, and would continue to oscillate for ever, but for
the effect of the resistance of the surrounding fluid, the inertia of which
continually diminishes the amplitude of its oscillations, and finally
extinguishes them at the end of a longer or shorter time, according to
circumstances. [It must not be inferred from this explanation, that the
particles of a fluid transmitting an undulation have any tendency to vibrate
for ever: on the contrary it has been admitted by the best writers on the
theory of sound, that all the motions which constitute it, as considered in a
fluid, are completely transitory in their nature, and have no disposition to be
repeated after having been once transmitted to a remoter part of the fluid.
T R. ]
Let us now consider in what manner the fluid is agitated by these
oscillations of the solid plane. The stratum immediately in contact with it,

being urged by the plane, receives from it at each instant the velocity of its
motion, and communicates it to the neighbouring stratum, which it forces
forwards in its turn, and from which the motion is communicated
successively to the other strata of the fluid; but this transmission of the
motion is not instantaneous, and it is only at the end of a certain time that it
arrives at a determinate [p118] distance from the centre of agitation. This
time is the shorter, as the fluid is less dense, and more elastic; that is,
composed of particles which possess a greater repulsive force. This being
granted, let us assume, in order to facilitate the explanation, the moment
when the moveable plane is returned to the initial situation, after having
performed two complete oscillations in opposite directions: at this moment,
the nascent velocity, which it had at first, is transmitted to a stratum of the
fluid removed from the centre of agitation by a distance which we may
represent by d. Immediately afterwards, the velocity of the moveable plane,
which has a little augmented, has been communicated to the stratum in
contact with it: “hence it has passed successively through all the following
strata;” and at the moment when the first agitation arrives at the stratum of
which the distance is d, the second has arrived at the stratum immediately
before it. Continuing thus to divide, in our imagination, the duration of the
two oscillations of the moveable plane into an infinity of small intervals of
time, and the fluid comprehended in the length d, into an equal number of
infinitely thin strata, it is easy to perceive, by the same reasoning, that the
different velocities of the moveable plane, at each of these instants, are now
distributed among the corresponding strata; and that thus, for example, the
velocity which the plane possessed at the middle of the first oscillations in
the direction of the motion, must have arrived, at the instant in question, at
the distance 34 d: so that it is the stratum at this distance which possesses at
the moment the greatest direct velocity; and in the same manner when the
plane arrived at the limit of its first direct oscillation, its velocity was
extinguished, and the same absence of motion will be found at the distance
1
2
d.

It is always supposed, that the oscillations of the plane are so minute in
comparison with the length d, that their extent may be neglected in this
calculation: and this hypothesis is actually consistent with the fact, since
there is every reason to suppose that the excursions of the incandescent
particles are very small in comparison with the extent of an undulation,
which, though an extremely minute space, is still an appreciable quantity,
and may be actually measured. Besides, [p119] even if the amplitude of these
oscillations were not in the first instance so wholly inconsiderable, it would
be sufficient to consider an undulation at a greater distance from the centre
of agitation, in order that their extent might be diminished in any required
proportion.
In the second, or retrograde oscillation, the plane, returning through the
same space, must communicate to the stratum of fluid in contact with it, and
to the rest in succession, a motion in a direction contrary to that of the first
oscillation; for when the plane recedes, the stratum in contact with it, urged
against the plane by the elasticity or the expansive force of the fluid,
necessarily follows it, and fills up the vacuum which its retrograde motion
tends to produce. For the same reason, the second stratum is urged against
the first, the third against the second, and so forth. It is thus that the
retrograde motion is communicated, step by step, to the most distant strata:
its propagation is effected according to the same law that governs the direct
motion; the only difference is in the direction of the motions, or, in the
language of mathematics, in the sign of the velocities which are imparted to
the molecules of the fluid. We see then that the different velocities which
have existed in the solid plane, during its second oscillation, must exist at
the moment which we are considering, in the different strata comprehended
in the other half of d, but with contrary signs. Thus the velocity, for
example, which the plane had in the middle of the second oscillation, which
is its maximum of retrograde velocity, must now be found in the fluid
stratum situated at the distance 14 d from the centre of agitation, while the
maximum of direct velocity is found, at the same instant, in the stratum
which is at the distance 34 d from the centre of agitation.

The extent of the fluid, agitated by the two opposite oscillations of the
solid plane, is what we call the breadth of an entire undulation, and we may
consequently give the name of semiundulation to each of the parts actuated
by the opposite undulations; the whole constituting a complete oscillation,
since it comprehends the return of the vibrating plane to the initial situation.
It is obvious, that the two semiundulations, which compose the complete
undulation, exhibit, in [p120] the fluid strata which they contain, velocities
absolutely equal in magnitude, but with contrary signs, that is to say,
carrying the particles of the fluid in opposite directions. These velocities are
the greatest in the middle of each of the semiundulations, and decrease
gradually towards their extremities, where they entirely vanish: so that the
points of rest, and of the greatest velocities positive and negative, are
separated from each other by intervals of one fourth of an undulation.
The length of an undulation, d, depends on two things: first, on the
promptitude with which the motion is propagated in the fluid; and secondly,
the duration of the complete oscillation of the vibrating plane; for the longer
this duration, and the more rapid the propagation of the motion, the greater
will be the distance to which the first agitation has been extended at the
instant of the return of the solid plane to its initial situation. If the
oscillations are all performed in the same medium, the velocity of
propagation remaining the same, the length of the undulations will be
simply proportional to the duration of the oscillations of the vibrating
particles from which they originate. As long as the vibrating particles
continue to be subjected to the same forces, it follows from the principles of
mechanics that each of their minute oscillations will occupy the same time,
whatever their extent may be; so that the corresponding undulations of the
fluid will continue to be of the same length; they will only differ from each
other in the greater or less extent of the elementary vibrations of the
particles, which will be proportional to the extent of the luminous particles;
for it appears from what has already been stated, that each stratum of the
fluid repeats exactly all the motions of the vibrating particle. The greater or
less amplitude of the oscillations of the strata of the fluid determines the
degree of absolute velocity with which they move, and consequently the

energy, but not the nature of the sensation which they excite, which must
depend, according to every analogy, upon the duration of the oscillations. It
is thus that the nature of the sounds, transmitted by the air to our ears,
depends entirely on the duration of each of the oscillations executed by the
air, or by the sonorous [p121] body which puts it in motion; and that the
greater or less amplitude or energy of the oscillations only augments or
diminishes the intensity of the sound, without changing its nature, that is, its
tone, or pitch.
The intensity of the light must depend then on the intensity of the
vibrations of the ether; and its nature, that is to say, the sensation of colour
that it produces, will depend on the duration of each oscillation, or on the
length of the undulation, the one of these being proportional to the other.
[We find, however, nothing in light of the same colour that is at all
analogous to the different register, quality, or timbre of a sound; by which,
for instance, the sound of a violin differs from that of a flute in unison with
it: the subordinate, or harmonic tones of the sound having nothing in light
to correspond with them. T R. ]
The duration of the elementary oscillation remaining the same, the
absolute velocity of the ethereal particles, at the corresponding periods of
the oscillatory motions, is, as we have seen, proportional to its extent. It is
the square of this velocity, multiplied by the density of the fluid, that
represents what is called the living force in mechanics, or otherwise the
energy or impetus of the particles, which is to be taken as the measure of
the sensation produced, or of the intensity of the light: thus, for example, if
in the same medium, the amplitude of the oscillation is doubled, the
absolute velocities will also be doubled, and the living force, or the
intensity of the light, will be quadrupled.
We must, however, take care not to confound this absolute velocity of the
particles of the fluid with the velocity of the propagation of the agitation.
The first varies according to the amplitude of the oscillations; the second,
which is nothing but the promptitude with which the motion is
communicated from one stratum to the other, is independent of the intensity
of the vibrations. It is for this reason, that a weak sound is transmitted by

the air with the same velocity as a stronger one; and that the least intense
light is propagated with the same rapidity as the brightest. When we speak
of the velocity of light, we always speak of the velocity of its propagation.
Thus, when we say that light passes through 200 thousand [p122] miles in a
second, we do not mean, according to the undulatory system, that such is
the absolute velocity of the ethereal particles; but that the motion
communicated to the ether employs only a second to pass to a stratum at the
distance of 200 thousand miles from its origin.
In proportion as the undulation becomes more distant from the centre of
agitation, the motion, spreading over a greater distance, must be weakened
in every part of the wave. It is shown by calculation, that the amplitude of
the oscillatory motion, or the absolute velocity of the particles concerned in
it, is inversely proportional to the distance from the centre of agitation.
Consequently, the square of this velocity is inversely proportional to the
square of the distance, and the intensity of the light must be inversely as the
square of the distance from the luminous point. It must be remarked, that,
for the same reasons, the sum of the living forces of the whole undulation
remains unaltered; for, on one side the length of the undulation d, which
may also be called its thickness, is invariable, and its extent of surface
augmenting in proportion to the square of the distance from the centre, the
quantity, or mass of the fluid agitated, is proportional to the same square:
and since the squares of the absolute velocities are diminished in the same
proportion as the masses have augmented, it follows that the sum of the
products of the masses by the squares of the velocities, that is to say, the
sum of the living forces, remains unaltered. It is a general principle of the
motion of elastic fluids, that however the motion may be extended or
subdivided, the total sum of the living forces remains constant; and this is
the principal reason why the living force must be considered as the measure
of light, of which the total quantity always remains very nearly the same, at
least as long as it continues to pass through perfectly transparent mediums.
It may be remarked, that black substances, and even the most brilliant
metallic surfaces, by no means reflect the whole of the light which falls on
them; bodies which are imperfectly transparent, and even the most

transparent, when of great thickness, absorb also, to use a common
expression, a considerable portion of the light that is passing through [p123]
them: but it must not be inferred that the principle of living forces is
inapplicable to these phenomena; it follows, on the contrary, from the most
probable idea that can be formed of the mechanical constitution of bodies,
that the sum of the living force must remain always the same, as long as the
accelerating forces tending to bring the particles to their natural positions
remain unchanged, and that the quantity of living force which disappears in
the state of light, instead of being annihilated, is reproduced in the form of
heat.
In order to obtain a correct idea of the manner in which the oscillation of
a small solid body occasions undulations in an elastic fluid, it has been only
necessary to consider a complete oscillation of the solid plane, which
produces an entire undulation. If we suppose the oscillations of the plane to
be continually repeated, we shall have a series of undulations instead of a
single one: and they will follow each other without intermission, provided
that the vibrations of the particle first agitated have been regular. Such a
series of regular and uninterrupted luminous motions I call a system of
undulations.
It is natural to suppose, on account of the prodigious rapidity of the
vibrations of light, that the luminous particles may perform a great number
of regular oscillations in each of the different mechanical situations in
which they are placed during the combustion or the incandescence of the
luminous body, although these circumstances may still succeed each other
in extremely short periods; for the millionth part of a second is sufficient to
exhibit, for example, 545 millions of undulations of yellow light; so that the
mechanical disturbances, which derange the regular succession of the
vibrations of the luminous particles, or which even change their nature,
might be repeated a million times in a second without preventing the
regular succession of more than 500 millions of consecutive undulations in
each state of the particle. We shall soon have occasion to apply this
observation to the determination of the circumstances in which the
interference of luminous waves is capable of producing sensible effects.

We have seen that each undulation produced by an oscillatory motion
was composed of two semiundulations, which [p124] occasioned in the
particles of the fluids velocities exactly equal in their intensity, though
opposite in the direction of the motions. Let us at first suppose that two
whole undulations, moving in the same line and in the same direction, differ
half an undulation in their progress: they will then be superinduced on each
other through one half of their length, or of their breadth, as we should say
in speaking of the waves of a liquid: but I here use in preference the term
length as applied to the interval between the two points which are similarly
affected by the motions of two consecutive undulations. In the supposed
case of the coincidence of one half of each of the undulations, the
interference will only take place with respect to the parts so coinciding: that
is, to the latter half of the first undulation, and the preceding half of the
second: and if these two semiundulations are of equal intensity, since they
tend to give, to the same points of the ether, impulses directly opposite, they
will wholly neutralise each other, and the motion will be destroyed in this
part of the fluid, while it will subsist without alteration in the two other
halves of the undulations. In such a case, therefore, half of the motion only
would be destroyed.
If now we suppose that each of these undulations, differing in their
progress by half the whole length of each, is preceded and followed by a
great number of other similar undulations; then, instead of the interference
of two detached undulations, we must consider the interference of two
systems of waves, which may be supposed equal in their number and their
intensity. Since, by the hypothesis, they differ half an undulation in their
progress, the semiundulations of the one, which tend to cause in the
particles of ether a motion in one direction, coincide with the
semiundulations of the other, which urge them in the opposite direction, and
these two forces hold each other in equilibrium, so that the motion is wholly
destroyed in the whole extent of these two systems of waves, except the two
extreme semiundulations, which escape from the interference. But these
semiundulations will always constitute a very small part of the whole series
to be considered.

This reasoning is obviously applicable to such systems only [p125] as are
composed of undulations of the same length; for if the waves were longer
one than the other, however small their difference might be, it would
happen at last that their relative position would not be the same throughout
the extent of the groups; and while the first destroyed each other almost
completely, the following ones would be less in opposition, and would
ultimately agree completely with each other: hence there would arise a
succession of weak and strong vibrations analogous to the beatings which
are produced by the coincidence of two sounds differing but little from each
other in their tone; but these alternations of weaker and stronger light,
succeeding each other with prodigious rapidity, would produce in the eye a
continuous sensation only.
It is very probable that the impulse of a single luminous semiundulation,
or even of an entire undulation, would be too weak to agitate the particles of
the optic nerve, as we find that a single undulation of sound is incapable of
causing motion in a body susceptible of a sympathetic vibration. It is the
succession of the impulse, which, by the accumulation of the single effects,
at last causes the sonorous body to oscillate in a sensible manner; in the
same manner as the regular succession of the single efforts of a ringer is at
last capable of raising the heaviest church bell into full swing. Applying this
mechanical idea to vision, supported as it is by so many analogies, we may
easily conceive that it is impossible for the two remaining semiundulations,
which have been mentioned, to produce any sensible effect on the retina;
and that the result of such a combination of the two systems must be the
production of total darkness.
If again we suppose the second system of undulations to be again
retarded half an undulation more, so as to make the difference of the
progress an entire undulation, the coincidence in the motions of the two
groups will be again restored, and the velocities of oscillation will conspire
and be augmented in the points of superposition; the intensity of the light
being then at its maximum.
Adding another semiundulation to the difference in the progress of the
two systems, so as to make it an interval and [p126] a half, it is obvious that

the semiundulations, superinduced on each other, will now possess opposite
qualities, as in the case of the half interval first supposed: and that all the
undulations must in this manner be neutralised, except the extreme three
semiundulations on each side, which will be free from interference. Thus
almost the whole of the motion will again be destroyed, and the
combination of the two pencils of light must produce darkness, as in the
case first considered.
Continuing to increase the supposed difference by the length of a
semiundulation at each step, we shall have alternately complete darkness
and a maximum of light, accordingly as the difference amounts to an odd or
an even number of semiundulations: that is, supposing always that the
systems of undulations are of equal intensity: for if the one series were less
vivid than the other, they would be incapable of destroying them altogether:
the velocities of the one series would be subtracted from those of the other,
since they would tend to move the particles of the ether in contrary
directions, but the remainders would still constitute light, though feebler
than that of the strongest single pencil. Thus the second pencil would still
occasion a diminution of the light: but the diminution would be the less
sensible as the pencil is supposed to be weaker.
Such are the consequences of the principle of the interference of
undulations, which agree perfectly, as we have seen, with the law of the
mutual influence of the luminous rays which is deduced from experiment:
for the results are expressed precisely in the same words, if we give the
name of length of undulation to the difference of routes which had been
represented by the symbol d. Admitting, therefore, as there is every reason
to believe, that light consists in the undulations of a subtile fluid, the period
d, after which the same effects of interference are repeated, must be the
length of an undulation.
It appears from the table already given for the seven principal kinds of
coloured rays, that this period d, or the length of the undulation, varies
greatly, according to the [p127] colour of the light, and that for the extreme
red rays, for example, it is [more than] half as great again as for the violet
rays situated at the other extremity of the spectrum.

It may easily be imagined that the number of different undulations is not
limited to the seven principal ones which are indicated in the table, and that
there must be a multitude of intermediate magnitudes, and others beyond
the red and the violet rays: for the ponderable particles, of which the
oscillations give rise to them, must be subjected to forces that are infinitely
varied, in the combustion or the incandescence of the bodies which excite
the motions of the ether: and it is on the energy of these forces that the
duration of each oscillation depends, and consequently the length of the
undulation produced by it. It is found that all the undulations comprehended
[in the air] between the lengths .0000167 E.I. and .0000244, are visible; that
is, are capable of exciting vibrations in the optic nerve: the rest are only
sensible by their heat, or by the chemical effects which they produce.
It has been remarked, that when two systems of waves differ half an
undulation in their progress, two of the semiundulations must escape from
interference; that six must be exempt when the difference amounts to three
semiundulations; and that, in general, the number of undulations exempt
from interference is equal to the number of lengths of a semiundulation
separating the corresponding points of the two systems. While this number
is very small in proportion to that of the waves contained in each system,
the motion must be nearly destroyed, as in the case of the exemption of a
single undulation. But it may be imagined that, as we increase the
difference of the progress of the two pencils, the undulations exempted
from interference may become a material portion of each group, and that it
may finally become so great as to separate the groups entirely from each
other; and in this case the phenomena of interference would no longer be
observable. If, for example, the groups of undulations consisted but of a
thousand each, a difference of one-twentieth of an inch in their routes
would be much more than sufficient to prevent the interference of the rays
of all kinds. [p128]
But there is another much more powerful reason which prevents our
perceiving the effects of the mutual influence of the systems of waves when
the difference of their routes is considerable; which is the impossibility of
rendering the light sufficiently homogeneous: for the most simple light that

we can obtain consists still of an infinity of heterogeneous rays, which have
not exactly the same length of undulation; and however slight the difference
may be, when it is repeated a great number of times, it produces of
necessity, as we have already seen, an opposition between the modes of
interference of the various rays, which then compensates for the weakening
of some by the strengthening of others; [while the shades of colour are not
sufficiently distinct to allow the eye to remark the difference.] This is
without doubt the principal reason why the effects of the mutual
interference of the rays of light become insensible when the difference of
the routes is very considerable, so as to amount to 50 or 60 times the length
of an undulation.
It has already been laid down as one of the conditions necessary for the
appearance of the phenomena of interference, that the rays which are
combined should have issued at first from a common source: and it is easy
to account for the necessity of this condition by the theory which has now
been explained.
Every system of waves, which meets another, always exercises on it the
same influence when their relative positions are the same, whether it
originates from the same source or from different sources; for it is clear that
the reasons, by which their mutual influence has been explained, would be
equally applicable to either case. But it is not sufficient that this influence
should exist, in order that it may become sensible to our eyes: and for this
purpose the effect must have a certain degree of permanence. Now this
cannot happen when the two systems of waves which interfere are derived
from separate sources. For it is obvious that the particles of luminous
bodies, of which the vibrations agitate the ether, and produce light, must be
liable to very frequent disturbances in their oscillations, in consequence of
the rapid changes which are taking place around them, which may [p129]
nevertheless be perfectly reconciled, as we have seen, with the regular
continuance of a great number of oscillations in each of the series separated
by these perturbations. This being admitted, it is impossible to suppose that
these perturbations should take place simultaneously and in the same
manner in the vibrations of separate and independent particles; so that it

will happen, for example, that the motions of the one will be retarded by an
entire semioscillation, while those of the other will be continued without
interruption, or will be retarded by a complete oscillation, a change which
will completely invert the whole effects of the interference of the two
systems of undulations which originate from them; since if they had agreed
on the first supposition, they would totally disagree on the second. Now
these opposite effects, succeeding each other with extreme rapidity, will
produce in the eye a continuous sensation only, which will be a mean
between the more or less lively sensations that they excite, and will remain
constant, whatever may be the difference of the routes described.
But the case is different when the two luminous pencils originate from a
common source: for then the two systems of waves, having originated from
the same centre of vibration, undergoing these perturbations in the same
manner and at the same instant, undergo no changes in their relative
positions: so that if they disagreed in the first instance at any given point,
they would continue to disagree at all other times; and if their motions
cooperated at first, they would continue to agree as long as the centre of
vibration continued to be luminous: so that in this case, the effects must
remain constant, and must therefore be sensible to the eye. This is therefore
a general principle, applicable to all the effects produced by luminous
undulations; that in order to become sensible, they must be permanent.
We have hitherto supposed that the two systems of waves were moving
exactly in the same direction, and that consequently their elementary
motions, to be combined with each other, were precisely limited to one
single line: this is the simplest case of interference, and the only one in
which the one motion can be completely destroyed by the other: [p130] for in
order that this effect may be produced, not only the two forces must be
equal and in contrary directions, but they must also act in the same right
line, or be directly opposed to each other.
The phenomenon of coloured rings, and that of the colours developed by
polarised light in crystallised plates, present a particular case of
interference, in which the undulations are exactly parallel. But in the
phenomena of diffraction, or in the experiment with the two mirrors, which

has been already described, the rays which interfere always form sensible
though very small angles with each other. In these cases the impulses to be
combined with each other at the same points, as belonging to the two
systems of undulations, will also act in directions forming sensible angles
with each other: but on account of the smallness of these angles, the result
of the two impulses is almost exactly equal to their sum, when the impulses
act in the same direction, and to their difference, when they are in contrary
directions. Thus, in the points of agreement or disagreement, the intensity of
the light will be the same as if the directions agreed more perfectly; at least
the nicest eye will not be able to discover any difference in them. But
although, with respect to the intensity of the light, this case of interference
resembles that which has already been considered, there are other
differences which modify the phenomenon very greatly, both with respect
to its general form, and to the circumstances necessary for producing it.
We may take, as a convenient example, the case of diverging rays
originating from the same luminous point, and reflected by two mirrors
slightly inclined to each other, so as to produce two pencils meeting each
other in a sensible angle: the two systems of waves will then meet each
other with a slight inclination; and it follows from this obliquity, that if a
semiundulation of the first system coincides perfectly in one point with a
semiundulation of the second, urging the fluid in the same direction, it must
separate from it to the right and left of the point of intersection, and must
coincide, a little further off, on one side with the preceding semiundulation
which is in a contrary direction, [p131] and on the other side with the
following semiundulation, and then be separated from this again, and at a
distance twice as great as the first, must coincide with the second
semiundulation before and behind it, of which the actions will coincide with
its own: whence there will arise, on the surface of this undulation, a series
of lines, at equal distances from each other, in which the motion is
destroyed and doubled alternately by the action of the second series. Thus if
we receive this luminous undulation on a white card, we shall observe on it
a series of dark and bright stripes, if the light employed is homogeneous; or

coloured fringes of different tints, if we employ white light for the
experiment.

This will be more easily understood by the inspection of a figure, which
represents a section of the two mirrors and of the reflected undulations,
formed by a plane drawn from the luminous point perpendicularly to the
mirrors represented by DE and DF. The luminous point is supposed to be
S, and A and B are the geometrical positions of its two images, which are
determined by the perpendiculars SA and SB falling from S on the mirrors,
taking in them PA = SP [p132] and QB = SQ. The points A and B, thus
found, are the centres of divergence of the rays reflected from the respective
mirrors, according to the well known law of reflection. Thus, in order to
have the direction of the ray reflected at any point G of the mirror DF, for
example, it is sufficient to draw a right line through B and G, which will be
the direction of the reflected ray. Now it must be remarked, that, according
to the construction by which the position of B is found, the distances BG

and SG will be equal, and thus the whole route of the ray coming from S
and arriving at b, is the same as if it had come from B. This geometrical
truth being equally applicable to all the rays reflected by the same mirror, it
is obvious that they will arrive at the same instant at all the points of the
circumference n′bm, described on the point B as a centre, with a radius
equal to Bb; consequently this surface will represent the surface of the
reflected undulation when it arrives at b, or, more correctly speaking, its
intersection with the plane of the figure: the surface of the undulation being
understood as relating to the points which are similarly agitated at the same
instant: the points being all, at the commencement of the whole oscillation,
for example, or at the middle or the end, completely at rest; and in the
middle of each semioscillation, possessed of the maximum of velocity.
In order to represent the two systems of reflected undulations, there are
drawn, with the points A and B for their centres, two different series of
equidistant arcs, separated from each other by an interval which is supposed
equal to the length of a semiundulation. In order to distinguish the motions
in opposite directions, the arcs on which the motions of the ethereal
particles are supposed to be direct, are represented by full lines, and the
maximum of the retrograde motions are indicated by dotted lines. It follows
that the intersections of the dotted lines with the full lines are points of
complete discordance, and of course show the middle of the dark stripes;
and, on the contrary, the intersections of similar arcs show the points of
perfect agreement, or the middle of the bright stripes. The intersections of
the arcs of the same kind are joined by the dotted lines b′p′, br, b′p′, and
those of arcs of [p133] different kinds by the full lines n′o′, no, no, n′o′: these
latter representing the successive positions or the trajectories of the middle
points of the dark stripes, and the former the trajectories of the bright bands.
It has been necessary to magnify very greatly in this figure the real length
of the luminous undulations, and to exaggerate the mutual inclination of the
two mirrors, so that we must not expect an exact representation of the
phenomenon, but merely a mode of illustrating the distribution of the
interferences, in undulations which cross each other with a slight
inclination.

It is easy to deduce from geometrical considerations, that the length of
these fringes is in the inverse ratio of the magnitude of the angle made by
the two pencils which interfere, and that the interval, comprehended
between the middle points of two consecutive dark or bright bands, is as
much greater than the length of the undulation, as the radius is greater than
the sine of the angle of intersection.
In fact the triangle bni, formed by the right line bi, and the two circular
arcs ni and nb, may be considered as rectilinear and isosceles, on account of
the smallness of the arcs; and the sine of the angle bni, considered as very
ib
small, may be called bn : so that bn being the radius, ib will represent the
sine of the angle bni, which has its legs perpendicular to those of the angle
AbB: consequently, these angles being equal, one of them may be
substituted for the other; and representing by i the angle AbB, formed by
ib
the reflected rays, we have bn = sin i
; consequently nn, which is twice bn,
2ib
will be equal to sin i
. But nn is the distance between the middle points of two
consecutive dark stripes, and is the distance which has been called the
breadth of a fringe; and ib being the breadth of a semiundulation, according
to the construction of the figure, 2ib will be that of a whole undulation;
consequently the breadth of a fringe may be said to be equal to the length of
an undulation divided by the [numerical] sine of the angle made by the
reflected rays [p134] with each other, which is also the angle under which the
interval AB would appear to an eye placed at b. We find another equivalent
formula, by remarking that the two triangles, bni and AbB, are similar,
whence we have the proportion bn: bi = Ab : AB, and bn = biAB × Ab
, or 2bn =
2bi × Ab
AB
: which implies that we may find the numerical breadth of a fringe by
multiplying the length of an undulation by the distance of the images A and
B from the plane on which the fringes are measured, and dividing the
product by the distance of the two images.
It is sufficient to inspect the figure, in order to be convinced of the
necessity of having the two mirrors nearly in the same plane, if we wish to
obtain fringes of tolerably large dimensions; for in the little triangle bni, the

side bi, which represents the length of a semiundulation, being little more
than the hundred thousandth of an inch for the yellow rays, for example, the
side bn, which measures the half breadth of a fringe, can only become
sensible when bn is very little inclined to in, so that their intersection may
be remote from ib; and the inclination of bn to in depends on the distance
AB, which is the measure of the inclination of the mirrors.
If A and B, instead of being the images of the luminous point, were the
projections of two very fine slits cut in a screen RN, through which the rays
of light were admitted from a luminous point placed behind the screen in
the continuation of the line bDC, the two paths described between the point
and the slits A and B being equal, it would be sufficient to compute the
paths described by the rays, beginning from A and B, in order to have the
differences of their lengths; and it is obvious in this case, that the
calculations which we have been making of the breadth of the fringes,
produced by the two mirrors, would remain equally applicable, at least as
long as each slit remained narrow enough to be considered as a single
centre of undulation, relatively to the inflected rays which it transmits. It
may therefore be said that the breadth of the fringes, produced by two very
fine slits, is equal to the length of an undulation supposed [p135] to be
multiplied by the interval between the two slits, and divided by the distance
of the screen from the wires of the micrometer employed for measuring the
fringes.
This formula is also applicable to the dark and bright stripes which are
observed in the shadow of a narrow substance, substituting the breadth of
this substance for the interval which separates the two slits, as long as the
stripes are far enough from the edges of the shadow: for when they
approach very near to the edges, it is shown, both by theory and by
experiment, that this calculation does not represent the facts with sufficient
accuracy; and it is not perfectly correct in all cases, either for the fringes
within the shadow, or for those of the two slits, but only for the fringes
produced by the mirrors, which exhibit the simplest case of the interference
of rays slightly inclined to each other. In order to obtain from the theory, a
rigorous determination of the situation of the dark and light stripes in the

two former cases, it is not sufficient to calculate the effect of two systems of
undulations, but those of an infinite number of similar groups must be
combined, according to a principle which will shortly be explained, in
treating of the general theory of diffraction.

ii. Rule for the Correction of a L UNAR O BSERVATION . By Mr. W ILLIAM
W ISEMAN , of Hull. ◊

R ULE .
A DD together the reserved logarithm (found as directed, page 111 and 112
of the Appendix to the third edition of the Requisite Tables) the log. sines of
half the sum, and half the difference of the apparent distance, and difference
of apparent altitudes, and 0.3010300, the log. of 2. Then, to the natural
number corresponding to the sum of these four logarithms, add the natural
verse sine of the difference of true altitudes, and the sum will be the natural
verse sine of the true distance.
Or, having obtained the natural number, as directed above, subtract it
from the natural cosine of the difference of the true altitudes, and the
remainder will be the natural cosine of the true distance. [p136]
E XAMPLE .
(From page 112, Appendix to Requisite Tables.)

Reserved log. from Tables (Req.) 9th and 11th 9.9938860
Log. sin. 43° 23′ 5″ = 12 sum of app. dist. and diff. app.
9.8368895
altitudes
Log. sin. 6° 45′ 36″ = 12 diff. ditto ditto 9.0708157
Log. of 2 0.3010300
Nat. num. to sum of 4 logarithms .1594488 9.2026212
Nat. vers. 37° 13′ 12″ = diff. true altitudes .2036812
Nat. vers. 50° 26′ 28″ = true distance .3631300
Or, Nat. cos. 37° 13′ 12″ = diff. true altitudes .7963188
Nat. number found above .1594488
Nat. cosin. 50° 26′ 28″ = true distance .6368700

D EMONSTRATION OF THE R ULE .
Let M′, S′, D′, d′ and M, S, D, d, respectively denote the true and
apparent altitudes, distances, and differences of true and apparent altitudes
of the moon and sun (or a star); then will the theorem answering to the
above rule be expressed by vers. D′ = 2 cos
cos M′ cos S′
M cos S
× sin 12 (D + d) ×
sin 12 (D−d) + vers. d′.
By Bonnycastle’s Trig. p. 175, the cosine of the angle contained by the
co-altitudes is coscos
D−sin M sin S
M cos S
= coscos
D′−sin M′ sin S′
M′ cos S′
; consequently the verse sine
of the same angle = 1− coscos
D−sin M sin S
M cos S
= 1− coscos
D′−sin M′ sin S
M′ cos S′
; that is,
cos M cos S+sin M sin S−cos D
cos M cos S
= cos M′ coscos
S′+sin M′ sin S′−cos D′
M′ cos S′
.
Substituting cos d and cos d′ for cos M cos S + sin M sin S and
cos M′ cos S′ + sin M′ sin S′. (Bon. Trig. p. 282), we have cos d−cos D
cos M cos S
=
cos d′−cos D′
cos M′ cos S′
; whence cos D′ = cos d′− cos M′ cos S′
cos M cos S
× (cos d−cos D); or, which is
the same, cos D′ = cos d′− cos M′ cos S′
cos M cos S
× (vers D−vers d); or, (Bon. Trig. p.
286.) [p137] cos D′ = cos d′− cos M′ cos S′
cos M cos S
× (2 sin212 D − 2 sin212 d); that is,
cos D′ = cos d′− 2 cos
cos M′ cos S′
M cos S
× sin 12 (D + d) × sin 12 (D−d); whence also
vers D′ = vers d′ + 2 cos
cos M′ cos S′
M cos S
× sin 12 (D + d) × sin 12 (D−d).
It may be observed, that Requisite Tables 9–11, answer logarithmically to
cos M′ cos S′
cos M cos S
; and the verse sines, and the cosines can be very readily taken out
of the tables in the Appendix. Also no ambiguity can arise from the
application of the rule before given: for all the arcs concerned in the
operation will always be (each of them) less than a quadrant, except the
resulting true distance, which cannot cause any ambiguity; and the verse
sines are given in the Appendix, to 126°.
E XAMPLE .
(Example 2nd, p. 39, Requisite Tables.)

Reserved log. from Tables 9 and 10 9.995307
Log. sin 62° 45′ 56″ = 12 sum app. dis. and diff. app. alts. 9.948971

Log. sin 40° 43′ 31″ = 12 diff. ditto ditto 9.814536
Log. 2 0.301030
Nat. num. corres. 1.147741 0.059844
Nat. vers. 22° 48′ 16″ = diff. true alts. 0.078167
Nat. vers. 103° 3′ 23″ = true distance 1.225908

De l’Influence des Agens Physiques sur la Vie. Par W. F. Edwards, D.M.,
Membre associé de l’Académie royale de Médicine de Paris, Membre de
la Société Philomatique, de la Société de Médicine de Dublin, &c. ◊

T HE researches of science among the phenomena of the physical world
have long obtained a high degree of estimation and interest in general
society; but it is of late years only that their application to living functions
has attracted much of the attention of the literary world.
The laws which govern the action of animal organs (the proper
department of Physiology) have usually been investigated by the medical
profession, to which they especially [p138] refer. Now we find the public
take some pains, and with reason, to inform themselves upon subjects
connected with physiological knowledge. A well-educated person, disposed
to philosophical inquiries, is not merely contented with the consciousness of
living, and the common information he derives of its means by experience,
but he seeks also to comprehend the relations subsisting between his own
organisation and the matters with which he is surrounded, and which at
once furnish him with nutrition, life, and support, and assail him with
disease and annihilation. His own instincts and observation, joined to the
more learned experience of his medical advisers, help him through the
precarious stages of life, and these may perhaps be sufficient for all its

purposes; and under this impression many will seek to know no more of the
secrets of nature.
But we live in an inquiring and scrutinising age, when the demand for
scientific principles is very generally urgent. All, therefore, relating to
organisation seems of equal interest with that appertaining to what is termed
the physical creation or inert matter.
Under this impression we have perused the book before us with great
satisfaction, and propose to present our readers with an analysis of the
valuable materials which it contains. We have some knowledge of Dr.
Edwards, a countryman domiciliated in France, and long resident in Paris.
We have confidence in his reports, and highly estimate his philosophical
skill, extensive acquirements, and accuracy of observation, ranking him
among the first physiologists of the age.
The work, now under consideration, contains an elaborate account of a
long series of experiments, instituted for the purpose of ascertaining the
influence of the physical agents upon animal life. These agents comprehend
the atmospheric air, water, and temperature; the two first constituting the
media in which all animals exist, and the last influencing in common the
inhabitants of both media. It is true, this is a subject by no means new, for it
has engaged the attention of experimenters from the earliest days of
science. But Dr. Edwards has diligently and patiently sought to investigate
the subject himself, to correct previous errors, and to embody the facts
which he has accumulated into a more complete and regular system than
heretofore adopted. In this attempt he has been eminently successful, and
has effected more perhaps than all who preceded him, availing himself,
nevertheless, of the experience of former inquiries.
The extent of his book, and the number of the experiments [p139] are
indeed somewhat appalling, but his clear and distinct method of
arrangement greatly facilitates the reader’s endeavours to master the
extensive subjects of his pages. As a book of reference it should find a place
in the library of every scientific society, and no individual devoted to
philosophy should omit the possession of it.

The agency of the air around us, water, and heat and cold, have often
been the objects of chemical inquiry, from their known great influence upon
the animal economy. The changes effected by the phenomena of animal life
upon these agents have been accurately examined, and partly reduced to a
mathematical precision of calculation.
Spallanzani and others have viewed the subject as it regards physiology,
but with such results as left the field open to subsequent investigation. Dr.
Edwards seems to have seized upon the deficiencies of his predecessors,
and, by going over their ground, and extending his own inquiries, he has
arrived at most interesting and important results. These he has divided into
four parts, as they relate to the different orders of the animal creation. The
first part includes some of the lower animals, particularly tenacious of life,
and of cold blood, such as frogs, toads, and salamanders. The second part is
devoted to other animals of cold blood, and of the vertebrated order, as fish,
and those reptiles which include lizards, snakes, and turtles. The third part
refers to warm-blooded animals; and the fourth part of the work is
dedicated to the influence of the physical agents upon the human race and
vertebrated animals. To these the author has added the discoveries of
modern times, relative to electricity on the animal economy, in an
Appendix. A collection of tables is appended to the work, exhibiting the
principal series of his experiments, as they regard the relative influence of
physical agents on the duration of life, and the phenomena resulting from
their mutual action.
The great importance of the four grand divisions of the work forbids our
hastily reviewing them, and we will endeavour to condense so much of the
information they contain as may forward the objects of our analysis. Dr.
Edwards thus announces the arrangement of his work:—
“Ces recherches auront donc rapport à l’air dans les conditions de quantité, de mouvement et de
repos, de densité et de raréfaction; à l’eau liquide et à la vapeur aqueuse; à la température, dans ses
modifications de degré et de durée; à la lumière et à l’électricité. Ces causes agissent à la fois sur
l’économie animale, ordinairement d’une manière sourde et imperceptible; et toujours [p140]
l’impression qu’on reçoit est le résultat de toutes ces actions combinées.”
“Lors même que, par l’intensité de l’une d’elles, il nous arrive de distinguer la cause qui nous
affecte, l’observation de l’effet se borne le plus souvent à la sensation, et les autres changemens qui
l’accompagnent nous échappent. On conçoit par la que l’observation la plus attentive des

phénomènes tels que la nature nous les présente, ne saurait démêler dans cette combinaison d’actions
l’effet propre à chaque cause, ni reconnaître des effets qui ne seraient pas révélés par la sensation.
“Il est une méthode qui règle les conditions extérieures, qui fait varier celle dont on veut apprécier
l’action, et qui fait juger, par la correspondance entre ce changement et celui qui survient dans
l’économie, du rapport de cause et d’effet: c’est la méthode expérimentale; c’est celle que j’ai suivie.
Pour en tirer parti il fallait, d’une part, déterminer l’intensité de la cause, d’autre part celle de l’effet.
La physique nous fournit ordinairement les moyens de remplir la première indication.”

In the true spirit of philosophical investigation, Dr. Edwards, in the first
place, proceeds to examine the action of physical agents upon the simplest
forms, and least elaborately developed organised beings, extending his
inquiries upwards, in the scale of the animal world, to man, the most perfect
creature, and the ultimate object of all physiological researches.
The peculiarity of constitution belonging to cold-blooded reptiles, among
which there is so little mutual dependance of organs, renders these the best
tests of the relative and proportionate influence of the different agents, the
intense action of which is liable to destroy the more perfect animals; and the
great development of the nervous system in the higher orders gives them a
wider and more acute range of sensibility. It is difficult, at all times, and
often impossible, to insulate corporeal functions among the warm-blooded
classes, so as to ascertain the amount and limits of physical agency. The
four classes of vertebrated animals, or such as are furnished with true
spines, afford ample means of comparative illustrations; and these
departments have engaged the author’s attention, in order to display the
result of the action of the same agent exercising a uniform influence upon
constitutions very differently constructed. The air, for example, exercises
its influence uniformly upon he four mentioned classes of vertebratæ, and
their different families are similarly exposed to the action of the atmosphere
by respiration.
Curious and interesting as is this subject, it is singular [p141] that, while it
was among the first to be noticed, it has been the latest in producing
satisfactory results. Among the opposing causes of the advancement of
knowledge in this department, the ignorance of our ancestors in chemical
science seems to be the principal. Without chemical aid it is perfectly
useless to attempt the investigation. The composition of the air respired

must be well understood; the different gases must be carefully examined, or
the physiological inquiry will be darkened and obscured.
Dr. Priestley laid the foundation of our chemical knowledge of gases in
their relation to respiration; but some time elapsed before it was understood
in what manner the air was connected with animal organisation. Oxygen
gas, one of the known constituents of atmospheric air, was Priestley’s
discovery, in its effect upon the blood, of converting this fluid from a dark
purple to a bright crimson. Lavoisier founded a chemical theory upon this
discovery of the agency of air, which was subsequently applied by Goodwin
to physiology. The latter author demonstrated, by a series of excellent and
correct experiments, that the exclusion of atmospheric air produces death in
animals, in consequence of the dark-coloured blood usually circulating in
the veins being prevented from becoming crimsoned. The state in which
any animal may be thus placed, is known by the term ASPHYXY , and by
which is to be understood a deficient or suspended aërification of the blood,
from whatever cause it may proceed that the atmospheric air is prevented
from access to the blood as it circulates through the lungs.
The great French anatomist, Bichat, pursued this subject still farther, and
published a treatise on Asphyxy. He sought, by numerous experiments, to
determine the threefold relation of the air to the nervous system, respiration,
and the circulation; and he arrived at this great and important conclusion,
that the VENOUS OR DARK BLOOD CIRCULATING THROUGH THE BRAIN,
CREATES A CESSATION OF THE FUNCTIONS OF THAT ORGAN, AND THAT IN
CONSEQUENCE THE HEART LOSES ITS ACTION . This discovery shows us at
once the direct cause of asphyxy in all its different degrees, according, in
effect, to the vitiated state of the blood from its deficient or suspended
aërification.
Le Gallois also investigated the subject of asphyxy; and he found that,
when dark blood circulated through the spinal marrow, the motions of the
heart ceased; and thus he not only determined the relations of the nervous
system to atmospheric air, but also those of the respiration and the

circulation, [p142] explaining the action of the air upon animals
physiologically.
In this inquiry warm-blooded animals were almost exclusively referred
to.
Spallanzani certainly investigated the action of the air on animals of cold
blood, but less in relation to the three grand objects of Bichat and Le
Gallois; and Spallanzani had the misfortune to live in an age when neither
chemistry nor physiology had made such advances as the present age has
produced.
Messrs. Humboldt and Provençal have, indeed, supplied much of this
deficiency, by their researches into the respiratory functions of fishes.
Nevertheless, the ground was still open, and our author has justly
appreciated the extent of former inquiries, and observed that the phenomena
of cold-blooded animals were too extraordinary to be noticed lightly, and
required much more extensive observation than was previously bestowed
upon them. With this impression, he proceeded to form an estimate of the
comparative influence of the air and water upon the nervous and muscular
systems of cold-blooded animals, which the singular modifications of life
among reptiles in particular afford ample means of ascertaining.
We know that these animals possess the extraordinary property of
existing a considerable time after the removal of the heart, with the free
exercise of their senses and of voluntary motion, notwithstanding the
suppression of the circulation. Dr. Edwards accordingly selected
salamanders for his first investigations, and removed the heart, with the
bulb of the aorta. Two of these were exposed to the free action of the air,
and the other two were submersed in water previously deprived of air by
boiling; a similar temperature being maintained in each medium. In four or
five hours, those submersed in the non-arëated water ceased to be active,
unless irritated, when they still appeared to retain voluntary power. One
died in eight, and the other in nine hours. The salamanders in air lived from
twenty to twenty-six hours and upwards. These comparisons were
frequently repeated, and upon frogs and toads, with the same results,
showing the experiments in air to be far more favourable to their existence

than with the animals submersed in the water. Eight hours were about the
maximum of the duration of life among the animals submersed in the water,
and twenty-nine among those exposed to the air; so that, independently of
respiration, the air is thus proved to be the most proper [p143] medium for
the action of their nervous and muscular systems, in their insulated state,
the respiration and the circulation of the blood being both suspended. As a
further corroboration of the superior vivifying property of the air over
simple water, when the same animals were plunged into unaërated water
during a certain time, as soon as they were, removed into the atmosphere,
they instantly revived; and their nervous and muscular systems were acted
on according as they were placed in either medium. Dr. Edwards also
confirmed the observation of Goodwin relative to the effect produced on the
colour of the blood. Properly speaking, the asphyxy comes on the instant
the air is excluded, the shades of difference in the colour of the blood being
referrible to the air left in the lungs after cessation of respiration.
The next point to determine was the influence of the air upon the same
animals exercising the respiratory function, and retaining their circulation,
compared with those deprived of these functions.
The difference of time in the two cases developes the influence which the
general circulation of the blood, free from aërial contact, exercises upon the
nervous system.
To ascertain this point, an equal number of frogs, deprived of the power
to exercise their respiratory and circulating functions, together with others
left entire, were respectively plunged into disaërated water. At times the
difference in favour of the untouched animals was twenty-four hours in
favour of the duration of life. Similar trials with toads and salamanders
produced the same results. In each case asphyxy came on; but the existence
of the animals which lived without the respiration and circulation was much
shortened. Thus the relative powers of life between the sole and insulated
action of the nervous system, and its action combined with the circulation
of dark blood, were estimated. The inference to be deduced, therefore, is,
that although disaërated blood furnishes but an ephemeral sort of existence,
it nevertheless exercises a comparatively favourable influence upon the

nervous and muscular systems, since it tends to the prolongation of the
action of these animal functions.
Dr. Edwards next proceeds to investigate the phenomena of asphyxy
produced by strangulation, or the mechanical obstruction to the access of
air to the lungs, and consequently to the blood. The same animals were
employed. When the windpipe was rendered impervious by ligature, the
muscles of the animals seemed to be paralysed directly; and although their
motions became subsequently revived at times, [p144] they never altogether
recovered their perfect freedom. As a comparative illustration, an equal
number of frogs were submersed in water, all of which died in about ten or
eleven hours, while those which were strangled lived from one to five days.
Salamanders continued active longest, and one did not cease to exist till the
eleventh day, although during this time he was in a complete state of
asphyxy from perfect strangulation.
Dumeril once found that a salamander lived a long time after
decapitation, even when the cicatrix of the wound was healed so as to stop
all access of air to the lungs.
In comparing the effects of strangulation with those of submersion or
drowning, it is to be supposed either that these animals exist a limited
period without the necessity of the nervous system being in contact with
atmospheric air, or that the air influences their blood through the
integuments of the body. Accordingly Dr. Edwards put this to the test by
making experiments upon cutaneous respiration.
Spallanzani found that the exposure of cold-blooded animals to the air
was attended with exudation of carbon, a phenomenon similar to that of
respiration. There appears, however, to be some source of error in these
experiments, for Spallanzani removed the lungs, and this operation rendered
the animal liable to the absorption of air and loss of blood. Dr. Edwards
sought to effect the same purpose by a different and more successful
measure. He also confined frogs in vessels of atmospheric air, and fastened
bladders round the head and neck, tight enough to stop the entrance of air to
the lungs. At the expiration of two hours the air was examined in the
bladder, and it was found to contain an excess of carbonic acid. The same

result was obtained from salamanders. It appears, therefore, that while air is
in contact with the skin, carbon is given out; but whether this be the effect
of exhalation merely, or that oxygen is actually absorbed, and carbon
transpired, is a question which led to further inquiries. Dr. Edwards,
therefore, inclosed cold-blooded animals in solid substances, in order to
determine the influence of dark-coloured blood, free of all external agency,
in the production of chemical changes, and to observe its sensible effect
upon the nervous system.
In the year 1779 three toads were confined in a box hermetically sealed,
and so deposited in the Academy of Sciences. Eighteen months after, the
box was opened, and one toad was found dead. These animals have been
found alive in blocks of coal after an imprisonment of some years, and have
[p145] also been sealed up during similar periods without perishing. Possibly
some hole or crevice might have admitted a little air. But, in Hevissant’s
experiment of 79, care seems to have been taken to obviate this suspicion.
Dr. Edwards, however, determined to put the question to the test. He
enclosed ten out of fifteen frogs in thick wooden boxes, and filled the
interstices with plaster, covering them over with the same substance, the
toads lying each in a central hole or bed. The other five toads were at the
same time submersed in water, and at the expiration of eight hours they
were found to be dead. In sixteen hours more, one toad was taken from a
box and found to be lively, and was reconsigned to its prison. On the
sixteenth day the toads in the boxes were discovered alive, and thus the fact
was established that these animals can live far longer in a state of asphyxy
confined in solid substances, than when submersed in water. This was
confirmed by repeated trials on salamanders, frogs, and toads. The frogs
perished quickest.
Thus an extraordinary fact is established, as regarding reptiles, since it
affords an exception to the general rule that all animals require a CONSTANT
supply of fresh air for the maintenance of their existence.
Similar trials were repeated in sand, and with the same results.
Dr. Edwards found that although a certain quantity of air enters the boxes
and sand, yet that it is far too little to maintain life. His conclusion,

therefore, stands, that animals of the kind employed can live longer in solid
substances than in a limited quantity of dry air.
It remains, however, to be considered in what manner these animals have
their lives extended beyond those exposed to the action of a body of air. Dr.
Edwards supposes the moisture of the sand to be one cause, since in the dry
air the animals become desiccated, the cutaneous transpiration being lost in
one case, and retained in the other, by the exclusion of air. A rapid and
abundant transpiration from the body, united with deficiency of air, seems
to be a greater cause of dissolution than confinement in solid substances
wherein there is no waste by transpiration.
The author’s inquiries are next directed to the influence of temperature
upon animals of cold blood, and two and forty experiments are practised
upon this subject, from the month of July to September following, during
which period frogs were submersed in aërated water, with a view of settling
the duration of life, acted on by varieties of temperature. The [p146]
continuance of life, generally, in these experiments, varied from one to two
hours and twenty-seven minutes. The mean term of life was one hour and
thirty-seven minutes, as averaged in July, and in September one hour and
forty-five minutes, the two extremes of the seasons approximating the
effects. The duration of the frog’s existence was greatest in the greatest
depression of temperature. Thus at ten degrees the duration of life was more
than double what occurred at sixteen or seventeen degrees, and at zero it
was about triple. As the heat was increased, the duration of life was
diminished; at forty-two the frogs died, and in the lowest temperature they
lived longest.
It appeared that at zero the frogs did not become stiffened, but retained
their motion, and their resistance to the frozen state is the cause of the
continuance of their existence at a low temperature. The cause of this
resistance is to be found in their peculiarity of constitution. Toads produced
similar results.
It may be alleged that frogs naturally live in climates at from forty to
forty-two; but, it is to be observed, that they are then placed in a situation of
liberty to come to the surface of the water to respire when they please;

whereas in these experiments their respiration is limited, from their inability
to reach the surface.
Taking a wider range of temperature, Dr. Edwards sought to ascertain the
influence of the seasons. In July and September frogs were found to live
from one to two hours and twenty-seven minutes in aërated water at fifteen
and seventeen degrees. In November they died at the end of more than
double this period, under the same temperature, and all other circumstances
being similar excepting the season. As the autumn advanced life was
prolonged.
To what are we to ascribe the modifications of the seasons? Probably to
circumstances appertaining to the intensity of light, to electricity, to
temperature, to the pressure of the atmosphere, to dryness and moisture,
&c.? Such existing causes naturally suggest themselves. But it appears that
little or no account can be rendered as to pressure, since its variations were
too trifling during the two seasons. Moisture could not effect an influence,
because the experiments were performed in water. The motion of the air
was also obviated. Of all the suggested modifications temperature alone
acted, and this, as it related to the surrounding air, was rendered ineffectual
by artificial temperature. The animals, therefore, could only be affected as
to the temperature of the [p147] seasons by that which preceded the
experiments. The modifications of the seasons, therefore, appeared to
influence the cold-blooded animals used in the experiments in this point of
view only. Accordingly we have this remarkable result, that the animals
lived twice as long in autumn as in the summer preceding, when plunged in
water of equal temperature. The seasons evidently influence their
constitutions, so as to extend the duration of life independently of other
causes, that is, from summer to autumn. Dr. Edwards endeavoured to
ascertain if it proceeds from atmospheric temperature, and he found that
frogs lived in aërated water at ten degrees, during November, from five or
ten to eleven, and even to forty hours, in some instances, the last term being
about double the duration of life in water of the same degree in summer.
This proves the remarkable dependence of the frog’s life under water, and
the temperature of the month preceding. Two curious facts are thus

developed by experiments instituted at different seasons. First, the influence
of the temperature of the water in which the animals were placed; and
secondly, the influence of the temperature of the air during certain periods
preceding the experiments, for in autumn the duration of life was about
double that of summer, and in winter he found the term to equal autumn, the
temperature of the air being in each comparative experiment artificially
raised to the same degree.
It appears from the foregoing experiments that frogs, toads, and
salamanders, exist in water according to its lowness of temperature, and that
their lives are prolonged by the temperature which precedes the experiment
being lowered. It then becomes a question, what are the limits of this
influence? This is to be ascertained by observing the greatest duration of
life among animals deprived of external air by submersion in water; and
noticing at the same time all the favourable circumstances dependent on the
concurrent temperature in prolonging life among the cold-blooded animals.
A point relative to the natural history of frogs first presents itself to our
notice. Spallanzani is of opinion that frogs do not pass the winter under
water, but retire in October from their native rivers into moist sands, in
which they make openings to breathe the air through, called by the Italian
fishermen il respiro della ranà.
M. Bose, and other French naturalists, found that frogs retire from
October to spring into water, but they give us no direct proof that they
constantly remain submersed. The presence of the observer may alarm the
frogs, and thus prevent [p148] their putting their heads above the water, so
that the assertion is but a negative kind of proof that they remain so long
under the water without coming up to respire, as some affirm. M. Bose
declares he watched frogs approach the surface at regular periods every day
during the winter season. Under the most favourable circumstances Dr.
Edwards found that frogs could not remain submersed, in winter, more than
two days and a half. Frogs are less active during winter than at the other
seasons, but they never lose their motion. Were it true, as Spallanzani thinks
it is, that they remained so long under water, it is probable that they would
become frozen in winter and die. Spallanzani derives his opinion from what

occurs with fish, forgetting that frogs are amphibious, and live as well on
land as in water; whereas fish are limited to a watery medium, and can,
therefore, furnish no example.
Dr. Edwards found that frogs, placed in certain quantities of aërated and
non-aërated water of an equal temperature, lived longest in the former; but
that the difference was not constant in its results, being often twice as long
in one case as in the other, as to the duration of life.
The next inquiry regarded stagnant water renewed at intervals, and in
this the duration of life was prolonged beyond the term of the last
experiments, and even to eight days. During winter when the temperature
was lowest the frogs remained active, though less so than in spring.
The conclusions to be drawn from these experiments are, that frogs pass
the winter in an animated state in water, not becoming stiffened as in ice,
and that they need not to approach the surface of the water in order to
respire, provided the water they inhabit be renewed at intervals; but if the
water be not renewed, or if disaërated water be employed, the frogs perish.
Considering that these animals are truly amphibious, these results are
very curious; and it is interesting in a physiological point of view, to know
that frogs are able to respire the air contained in the dense medium of water
for an indefinite period, and just as easily as they breathe the finer medium
on land.
Respecting the action of aërated water on the skin, the conclusion drawn
seems to be correct, that it must be from cutaneous absorption that the air
contained in the water promoted the continuance of life in Dr. Edward’s
experiments upon this point, since the animals were in a state of asphyxy
regarding respiration by the lungs; and that no [p149] air entered in
combination with water was shewn from Dr. Edwards never having seen
water in the lungs. Therefore, unless the air acted on the blood through
some other organ, the lives of these animals would be definite and
shortened, even though the water be renewed from time to time, and their
asphyxy would be complete and continued. And since the skin is the only
organ in contact with the air, it is fair to conclude that it is the medium of
aërial absorption.

When the webs were examined under water, these membranes indicated
the action of air upon their blood-vessels, by the bright tint of the blood.
Spallanzani imagined that frogs perish sooner in running than in stagnant
water; but Dr. Edwards having secured some of these animals in ten feet of
the Seine, whilst others were simultaneously placed in unrenewed stagnant
water, he found the latter did not survive many hours, and the former lived
a long time.
In order to fix the limits of this kind of existence, frogs were placed in
renewed aërated water, and with a temperature never forced beyond ten
degrees they were found to live in all seasons of the year; but when the
temperature was elevated from twelve to fourteen, they died in a few hours.
In running streams they lived longest, and at twelve degrees they were thus
more favourably placed than in stagnant water, at a lower temperature even,
and taking the precaution to renew the water daily; and at seventeen degrees
in running water they died prematurely. Toads exhibited the same
comparative results, but they lived the longest.
It appears, therefore, that water contained in vessels is less favourable to
the lives of these animals than running streams, although the water and the
temperature were identical. Probably the great advantage of running water
is its constant and unceasing renewal. The separate and comparative
influence of air, water, and temperature, being thus investigated, the
combined action of the three physical agents was next inquired into, and it
is demonstrated that frogs submersed in water are influenced by three
circumstances,—1. the presence of air in water; 2. the quantity of its
renewal; 3. the temperature of the medium. If the manners of frogs be
closely examined, they appear to live in water under very considerable
influence from the atmosphere.
From circumstances developed in the foregoing experiments, cutaneous
respiration seems to be pretty evidently indicated. A chapter is, therefore,
devoted to this subject, one that is not well known, although pulmonary
respiration is [p150] generally understood. In frogs, the function of
pulmonary respiration is united with that of deglutition, and the air enters
only by the nostrils, the mouth being closed during respiration. While the

mouth remains open, the action of deglutition is stopped, and, therefore, the
animal does not then breathe. Dr. Edwards availed himself of this
circumstance by gagging the mouth so as to keep it open, and thus prevent
the air from entering the lungs. The frogs were sufficiently exposed to
moisture and renewal of air to their bodies: the results were, that, at twenty-
four degrees, five frogs so placed died next day, and one lived a week.
Dr. Edwards immersed some frogs in wet sand, and adopted an improved
method of excluding air from the lungs, and some of them lived twenty
days. Hence it evidently appears that air influences the skin materially, and
counterbalances the asphyxious state induced by obstructing the air’s
passage to the lungs. By adopting other methods, the existence of frogs was
prolonged to thirty or forty days. It is, therefore, sufficiently proved that the
blood undergoes its necessary changes from atmospheric influence through
the medium of the skin, although in a minor degree compared with those
which it passes through from pulmonary respiration. Frogs are thus shewn
to possess a double source of respiration.
By substituting oil for water, frogs immersed in this fluid died in a few
hours, being at liberty to breath the air on its surface. And, when plunged
into oil, with the means of breathing by the lungs arrested, they lived an
equal time with frogs simultaneously placed in water without power to
respire. A comparison was instituted with frogs in oil and in water, being
allowed to breathe air, when the difference was found to be very
considerable in favour of the aquatic bath. These circumstances shew, that,
even with the feeble succour of the air through the skin, absorbed from the
water, the respiratory function was far more prolonged, than in the case of
the obstruction afforded by the oil. Thus we have abundant evidence of the
double function by which frogs are maintained, from the action of the air on
the skin and the lungs; and this appears to be the means of existence among
amphibious animals generally.
It may be asked why these animals die in deep water when prevented
from approaching the surface? It appears that, having expelled the respired
air from their lungs, which is imperfectly renewed from the water, they
become specifically heavier than the water, and unable to rise from the

bottom; and thus placed, the duration of their lives depends upon [p151] the
resistance offered by their constitutions to the depressing effects of a state
of asphyxy while remaining submersed.
Dr. Edwards next proceeds to inquire into the effects of TRANSPIRATION .
A liquid transfusion from the skin of animals is constantly going on, either
in the form of vapour or of fluid in a denser state.
The latter constitutes sweat. This phenomenon exhibits great variations,
and it is important to know what diminution of weight the body suffers in
different circumstances. In the course of an hour remarkable fluctuations
occur.
Dr. Edwards suspended frogs, toads, and salamanders, in a calm air,
weighed them, and noted the results, which, though very changeable in an
hour, were generally uniform in three, and in nine hours they averaged an
equal result. The successive diminution in the mass of fluids was evident.
The results were modified by the alternate position of the animals in a
body of air in repose, or agitated by a draft. And these results do not appear
to depend upon any principle of vitality, for they take place equally in death
and in life, and indeed among unorganized bodies, as, for example, lumps
of charcoal soaked in water. Therefore the cause of the phenomenon of
transpiration seems to be referrible entirely to physical agents. The motion
of the air seems to be its exciting cause; for even when, to all appearance, it
is calm, it is in reality agitated more or less, and produces a sensible
evaporation from the skin. But the difference between the effect of calm and
agitated air is remarkable; for in a draft, the animals exposed to it sweated
away double the quantity of liquid compared with those confined in a room
shut up. The amount lost was proportioned to the intensity of the wind, and
reached a triple amount over those animals in stagnant air; and this fact
explains the variations noticed from hour to hour among animals exposed to
currents of air.
The transpiration which occurs in very moist air, always amounts to a
diminution of weight; but in dry air it is five or ten times greater; and when
the influence of a moist state of the atmosphere is compared with that of a
dry state, the amount of evaporation is equal to that of a dry and calm air.

Transpiration may, therefore, be referred to the agitation of the
atmosphere for its exciting cause, beyond any modifications of its density.
And, although an elevated temperature be favourable to transpiration, its
modifying influence is less than that of other causes.
In comparing the effects of absorption and transpiration, [p152] in water
and in air, frogs were found to gain an addition to their weight according to
the term of their continuance in the former medium. An absorption of water
was rendered evident by the loss of bulk it had sustained, when measured
after the experiment.
Thus, when the comparative influence of water and air is estimated, the
former appears to be absorbed, and adds to the weight of the body; and the
latter tends to diminish the weight, by different and fluctuating degrees of
evaporation taking place, and dependent much more on the degree of
motion in the air, than on its dryness or humidity: these last conditions
modify evaporation in a minor degree, when compared with the influence
of a current of air.
The celerity of absorption exceeds that of transpiration six times, in the
most rapid cases. It therefore results, that the losses by transpiration in air
should be repaid by absorption of water in a much less time than the
expenditure occurs. But the decrease of weight is not prolonged; it is
sudden, and not continuous, alternating with augmentation of weight, by
absorption of liquid going on in a ratio superior to the loss; and thus
nature’s provision is manifested for the nutriment of the body.
With this last inquiry Dr. Edwards concludes the first part of his work;
and it is observed, that, with regard to transpiration, the losses of weight
have been considered without reference to the existence of any other
influence than water. The losses by transpiration have been examined
generally without regard to the matters lost. What relates to water differs
essentially in one respect from that which regards the air. The losses
sustained by the body ought to be more particularly examined. Temperature
and loss of time require estimation. An excretion of solid matter evidently
takes place; for the water, in which animals are submersed, becomes turbid,

especially in hot weather, and it sensibly contains animal matters, affecting
the weight of the body in water.
When animals are submersed in water, their skins exercise two functions,
acting inversely in determining their weight. And it results, from
comparative experiments, that the absorption at zero exceeds the loss in
water; while at thirty degrees the loss exceeds the increase by weight from
absorption; and the higher the temperature, the greater is the excess in the
discharge of animal matters. We may therefore presume, that the agency of
temperature produces analogous effects, upon aërial transpiration, to those
before observed [p153] in other inquiries; and the effects of dryness and
moisture in the air produce a minor degree of influence also, when
compared with temperature, on the losses of animal substances.
We have been thus minute in our analysis, because the subject of it is
new to science in its present shape, and of a high degree of interest. Dr.
Edwards’s researches among the different classes of animals have tended
more to the illustration of the influence of physical agents upon life than
any previous authorities; and the persevering industry, accuracy of
observation, and patient inquiry which he has evinced in his investigations
among cold-blooded animals, have placed this department of the creation in
a point of view at once curious, interesting, and valuable to science. We
attach the greater importance to this part of the author’s work, as it is a
ground on which he may be consulted, and quoted as indisputable authority,
until equal inquiries have shewn him to be fallacious.
Our limits will not at present permit us to proceed farther in our analysis,
and we must refer the remainder of the book to a future opportunity. The
subjects of the three other parts, though greatly extended, will not probably
require such minute analysis as those novel experiments which form the
subject of the first part; but we imagine that the application of the principles
laid down, in the previous inquiries, to human physiology, will be found not
less interesting than those which relate to the natural history of the lower
orders of the animal creation.

An Account of Professor Carlini’s Pendulum Experiments on Mont Cenis. ◊

W E believe that no account of Professor Carlini’s pendulum experiments on
Mont Cenis has hitherto appeared in the periodical scientific publications of
this country: the experiments are, however, well deserving of such notice,
having been conducted with great care, and having had a specific object in
view, which object seems to have been satisfactorily accomplished. The
following brief account of them, taken from the original memoir published
in the Appendix to the “Ephéméride di Milano” for 1824, may not be
unacceptable to those of our readers who interest themselves in subjects of
this class.
The length of the simple pendulum vibrating seconds is a [p154] measure
of the intensity of gravitation; i. e. of the excess of the force of gravity over
the centrifugal force. In consequence of the ellipticity of the earth, and of
the difference in the direction of the two forces, the intensity of gravitation
varies according to the different latitudes. It also varies, in the same
latitude, according to the greater or less elevation of the pendulum above
the level of the sea; i. e. according to its greater or less distance from the
centre of the attracting force.
Had the earth a perfectly level surface, such, for instance, as it would
have if it were everywhere covered by a fluid, the force of gravity, in
receding from the surface, would diminish in the duplicate proportion of the
distance from the earth’s centre. In the actual state of the globe, however, its
continents and its islands are raised above the general level of the sea by
which it is only partially covered; and if a pendulum be raised, on the
surface of the land, to a known elevation above the sea, the diminution of
gravity will not be, as in the more simple case, proportioned to the squares
of the respective distances from the earth’s centre, but that proportion will
require to be modified, by taking into account the attraction of the elevated
materials, interposed between the general surface and the place of
observation.

When pendulums are employed in different latitudes, to obtain the ratio
of gravitation between the equator and the pole, for the purpose of deducing
the ellipticity of the earth, all the places of observation, being on land, are
more or less elevated above the sea; inland stations, in particular, are
sometimes at considerable elevations: to render these results comparable
one with another, it is necessary to reduce each result to what it would have
been, had it been made at some level common to all the experiments; and
the surface of the sea has hitherto been taken as that common level.
Previous to the publication of a paper of Dr. Young’s in the Philosophical
Transactions for 1819, the consideration which we have mentioned, that of
the attraction of the matter interposed between the place of observation and
the level of the sea, was generally unheeded in estimating the allowance to
be made for the reduction of different heights to the common level: in that
paper, however, Dr. Young took occasion to point out the probable effect of
[p155] the interposed matter in modifying considerably the usual allowance;
that, supposing its density to be about half the mean density of the earth, the
effect of an hemispherical hill of such matter, on the summit of which the
pendulum should be placed, would be to diminish the correction, deduced
from the duplicate proportion from the earth’s centre, about 15 ; that, in like
manner, a tract of table-land, considered as an extensive flat surface, of the
same relative density, would diminish the correction about 38 ; and that,
accordingly, in almost any country that could be chosen for the experiment,
the proper correction for the height would vary, according to the form and
density of the interposed materials, from rather more than a half to rather
less than three-quarters of the usual allowance. This view has been
subsequently acted upon by the English pendulum experimentors, in
reducing their observations; but it has not been yet adopted by the French.
The experiments of Professor Carlini were calculated to afford a practical
illustration of the correctness of Dr. Young’s reasoning.
Professor Carlini was engaged, in the summer of 1821, in concert with
Professor Plana, in determining the amplitude of the celestial arc between
the Hospice on Mont Cenis and the Observatory at Milan, by means of fire-

signals made on the Roche Melon, and observed simultaneously at Milan
and at a temporary observatory established at the Hospice. Whilst thus
engaged, Professor Carlini, being stationary for several days on Mont
Cenis, and obliged to have time very accurately determined, for the purpose
of comparing with the observatory at Milan, availed himself of the
opportunity to employ a pendulum apparatus of the same general nature as
that used by M. Biot at Paris, which had been prepared at Milan some years
before, under the direction of a commission of weights and measures, with
the view of determining the value of the divisions of the national linear
scale. As this apparatus differed in some few particulars from the original
employed in France, we shall briefly notice the differences, presuming our
readers to be acquainted with the apparatus of MM. Borda and Biot.
1. In the Milan apparatus, by means of two microscopes furnished with
wire micrometers, the length of the pendulum [p156] may be measured
without touching it; without approaching it; without even opening the case
which contains it. The measure is obtained by bringing the wires in contact
with the images of the knife-edge suspension, and of the upper and lower
borders alternately of the platinum disk suspended to the thread: thus
preventing the risk of deranging the equilibrium, and avoiding the effect
which the heat of the body might have on the dilatable metallic thread.
2. The half sum of the distances taken between the suspension, and the
upper and lower edges of the disk, gives the distance of the centre of the
disk itself; without measuring its diameter with a compass, an operation
exceedingly difficult to execute with the necessary precision. By this
apparatus of microscopes the length may be measured at pleasure, even
during the time of oscillation; and being attached to the wall, instead of
supported by the floor, the risk of derangement by the tread of the observer
is avoided.
3. The pendulum, and the clock by which its oscillations are measured,
were not, as usually, near together and resting on the same base, but were
perfectly separated. The coincidences of the oscillations were observed, by
bringing the image of the pendulum of the clock, reflected by means of an
oblique mirror, in contact with the image of the simple pendulum seen

direct through a telescope. By this modification the risk of the mutual
influence of the pendulum and the clock is avoided.
4. The disk was attached to the thread by means of knots in the thread
itself; avoiding the correction for the small cup usually employed for that
purpose.
5. An alteration was made in the weight and shape of the knife-edge
suspension; reducing its weight to about 10 grains, and giving it the shape
of a rotella, instead of that of a triangular prism.
The simple pendulum and microscopes were attached to a strong wall, in
a room on the ground floor, contiguous to the temporary observatory, and
well sheltered from the sun and weather. The clock with which the
pendulum was compared, was supported by a pyramid of masonry resting
on the ground, and occupying the middle of the room. The experimental
length between the microscopes was referred to three standard metres, [p157]
in perfect agreement with each other: one received from Paris by the
Commission of Weights and Measures at Milan; a second brought more
recently from Paris by Conte Moscati; and a third in the possession of the
Royal Academy of Turin.
The experiments were commenced on the 3rd of September, and
terminated on the 27th, being interrupted by M. Carlini’s absence at
Chambery from the 7th to the 12th. The distance between the microscopes,
and the oscillations and length of the pendulum, were measured alternately.
Thirteen independent results were thus obtained, of which the greatest
13
discordance from the mean was not more than 10000 ths of a British inch.
The mean result was 39.0992 British inches, the length of the pendulum
vibrating seconds in a vacuum, at the place of observation on Mont Cenis,
1943 metres, or 6374 feet above the sea, in the latitude of 45° 14′ 10″. To
compare with this determination, we may obtain a tolerably fair
approximation to the pendulum at the level of the sea in the latitude of
45° 14′ 10″, such as its length might have been found, if the mountain could
have been removed and the pendulum placed on its site, by deduction from
the lengths actually measured with a similar apparatus, on the arc between

Formentera and Dunkirk, at stations not far removed from the level of the
sea, in the adjacent parallels to Mont Cenis, and in the countries adjoining.
Of these there are five, not including the station at Clermont, in
consequence of its great elevation: they are as follows:—
its pendulum
Dunkirk 51° 02′ 10″; at the level
of the sea = 39.13771
Paris 48 50 14 ; ditto 39.12894
Bordeau 44 50 26 ; ditto 39.11295
Figeac 44 36 45 ; ditto 39.11212
Formentera 38 39 56 ; ditto 39.09176
The mean length of the seconds pendulum at the level of the sea, in the
latitude of 45° 14′ 10″, deduced from these determinations, is 39.1154; and
1 1
it is so equally, whether an ellipticity of 288 th, or of 304 th, or any
intermediate ellipticity, be assumed in the reduction.
We have, then, 39.1154−39.0992 = ·0162 inch., as the [p158] measure of
the difference in the intensity of gravitation at the place of observation
elevated 1943 metres; and at the level of the sea. The radius of the earth,
being 6,376,478 metres, this measure, according to the duplicate proportion
of the distances from the earth’s centre, should be ·0238 inch. The attraction
of the mountain is, then, equal to ·0238−·0162 = ·0076 inch. Whence it
appears that, in this particular instance, the correction for the elevation is
68 7
reduced, by the attraction of the interposed matter, 100 ths, or to about 10 ths
of the amount immediately deducible from the squares of the distances.
It is obvious that, if we possessed a correct knowledge of the density and
arrangement of the materials of which Mont Cenis is composed, so as to
enable a computation of the sum of all the attractions which they exercise
on the place of observation, this result might furnish, as well as Dr.
Maskelyne’s experiments on the deviation of the plumb-line produced by
the attraction of Mount Schehallien, a certain determination of the mean
density of the earth. Professor Carlini considers that the form of the

eminence may be sufficiently represented by a segment of a sphere, a
geographical mile in height, having as its base a circle of 11 miles diameter,
the distance from Susa to Lansleburgo; the attractive force, on a point
placed on the summit, would, in such case, be equal to 2 π δ (1− 23 √ 11
1
) or in
numbers to 5·020 δ, δ being the density of the mountain, and 2 π the ratio of
the circumference to radius. The attractive force of the earth, on a point at
its surface, is 43 π r Δ, = 14394 Δ, r being the radius of the earth = 3437
geographical miles, and Δ its mean density. Now these two quantities,
14394 Δ and 5·020 δ, should be, to each other, in the proportion of 39.1154,
—the pendulum at the level of the sea, representing gravitation at the
surface of the earth,—to ·0076, the portion of gravitation at the summit of
the mountain due to the attraction of the mountain. By the observations of
M. de Saussure and other geologists, Mont Cenis is chiefly composed of
schistus, marble, and gypsum; the specific gravities of which substances
were ascertained, from numerous specimens in the possession of M. Carlini,
to be respectively as follows:— [p159]
The schistous 2·81.
The marble 2·86.
The gypsum 2.32.

In the absence of a precise knowledge of the quantity and position or
each of these three component parts, we may take the mean, 2.66, of their
several densities as approximatively the density of the mountain, = δ. We
have then
Δ = 5.02 δ × 39.1154
14394 × ·0076
= 4.77,

a result differing little from that of Cavendish as recently corrected by Dr.
Hutton, and still less from that of the Schehallien experiments.
The most hypothetical element of this calculation is the width assigned to
the base of the mountain; but by the very nature of the question, it has but
little influence on the final result; since, by even doubling the assigned
diameter, the total attraction would not be altered a twentieth. In regard to

the mean density of the mountain, if it were taken at 2.75, instead of 2.66,
that of the earth would result 4.94, instead of 4.77, as given above.
E. S.

Transactions of the Horticultural Society. Vol. vii. Part 1. 4to. London,
1827. pp. 208. ◊

I. Observations upon the Growth of Early and Late Grapes under Glass. By
Mr. James Acon. ◊

F EW gardens are to be found in which bunches of fresh ripe grapes can be
gathered every day in the year: notwithstanding the importance of the fruit
to the luxurious, and the facility with which the vine submits to the artificial
climate of the forcing-house. Nothing is easier than to secure crops of
grapes in a vinery during the spring and summer months; but it is far more
difficult to obtain them in the last and earliest seasons of the year, when the
plants would [p160] naturally be in state of torpidity. It is well known that
this desirable purpose is attained in great perfection in the garden of the
Earl of Surrey, at Worksop Manor; and the management there practised is
the subject of this paper.
The common methods of forcing early grapes are to train the vines under
the roof near the glass, or on small frames against flued walls; but to both
these practices Mr. Acon finds great objections: to the former because it
renders the house too dark, and exposes the young and tender branches to
the pernicious effect of blasts of cold air rushing through the interstices of
the panes; and to the latter, because the heat of the flues is apt to scorch the
branches, and in consequence to destroy the crop,—excessive heat in the
one case producing the same injurious effects as excessive cold in the other.
The following are the two modes by which Mr. Acon obtains his very early
and his very late grapes. For the early crops a house is used, of which the

back wall is 9.6 feet in height, and the front wall 3 feet, the roof forming an
angle of about 30 degrees. It is heated, from the absolute necessity of
employing an atmosphere of unusually high temperature, with two flues
that pass along the middle of the house, and return in the back wall; a fire-
place being built at each end of the house. Forcing begins on the first of
September, and the fruit begins to ripen the first week in March. The vines
are trained upon a trellis, fixed over the flues, in the centre of the house, and
also upon the back wall; but none are allowed to obstruct the light by
occupying the roof, until about six weeks after the forcing has commenced,
when some new shoots are introduced and trained to the rafters. The form
of this house gives it a peculiar advantage, in presenting a greater surface
for the growth of vines than can be derived from any other plan; the trellis
which is placed over the flues is nearly equal to the whole roof, without
being in any degree injurious to the plants trained upon the back wall. The
vines are planted in the inside of the house, but in such a manner that the
mould in which they grow is not heated by the fire-places of either flue. The
usual mode of exposing the main stem of a forced vine to an extremely low
temperature in the external air, while the branches are stimulated by a very
high temperature in an entirely different atmosphere, is very properly
objected to. Nothing, in fact, can be more injudicious than such a practice,
in cases where very early forcing is required; for it should be borne in mind,
that although the absorption of the elements by which the proper juices of a
[p161] plant are elaborated, and brought into the state under which they
appear in the fruit, and in the secretions of the plant, is carried on by the
leaves alone, yet that all these juices have, in the first instance, to pass along
the vessels of the stem before they reach the leaves; and that the whole of
the bark of a tree is, rightly considered, a leaf of a particular description,
formed of the same kind of tissue, and exercising the same functions, and
undoubtedly producing a powerful effect upon the motion of the fluids of
the branches, with the vessels of which it is elaborately and intimately
entangled, from the core to the circumference. No argument can be
necessary to show that an equal action of the vessels of a plant is
indispensable to the due maintenance of the vegetable functions in a healthy

state, and that this is not to be maintained by exposing the main stem and
the extremities to an atmosphere and temperature entirely different. Such
irregularities do not exist in free Nature, and she will not submit to them
when in fetters.
In pruning vines for early forcing, as little wood should be employed as
possible. Mr. Acon stops the shoots one joint above each cluster, and has no
joint without a bunch. When the crop is over, and the wood perfectly
matured, the branches should be laid near the ground, and shaded till the
recommencement of forcing. In short, they should be placed in a condition
as nearly as possible resembling the gloom and cold of winter. If this
process be well managed, the vines will alter their natural habits, and
instead of budding with the spring, their vegetation will naturally
commence at the period at which they have been accustomed to be
stimulated.
For late grapes, a house of a different construction is employed. The back
wall is 12 feet high, the front wall 1 12 foot, and the roof lies at an angle of 45
degrees. The heat is supplied by a single flue passing along the middle of
the house. The sorts best adapted for late forcing are the Muscat of
Alexandria, the St. Peter’s, and the Black Damascus; all other kinds wither
prematurely. This house is generally shut about the middle or end of May,
as soon as the bunches become visible. The vines are trained on a trellis
near the glass. Till they are out of blossom the air is kept very warm, a point
to which much importance attaches, because it is during this period that all
the branches that are to bear fruit in the succeeding season are produced. In
a high temperature, the branches will grow more compactly, and [p162] will
be more regularly matured than in a low temperature, in which the wood is
apt to become excessively luxuriant, and not to ripen well. Great attention
must be paid to this point. As much air as possible is introduced into the
vinery during the summer; but as the autumn advances, more caution in this
respect is observed. The fruit should be perfectly coloured at the approach
of the dark season; for if the colouring be deferred too long, the berries will
never acquire their proper flavour. Great care must be observed to remove

daily such berries as are inclining to damp, or the whole crop will soon be
spoiled. This should be particularly attended to; for the contagion of what
gardeners call damp, arises from the growth of minute fungi which vegetate
upon the epidermis, and spread during the autumn with alarming rapidity
from bunch to bunch.
The pruning of vines for late forcing is the same as has been already
explained. When the crop is gathered, the house is unroofed for a short
time, in order to expose the branches to a low temperature, and to the
degree of humidity necessary to replenish their vessels, which have been
drained by the dryness of the climate in which, when forced, they were
necessarily kept.
By the means above described, a regular supply of grapes is secured
through the year. The late-house crop lasts from the middle of January to
the end of March; it is succeeded by the first crop in the early-house, which
carries on the supply into May, and it is continued by the grapes on the
rafters in the same house until the vines in the pine stoves, which are forced
early in January and February, produce their crops. These continue bearing
through the summer, when a vinery, of which the forcing commences about
the end of March, furnishes the supply till the late-house fruit is ready in
January.
Upon the whole this may be considered a most instructive and valuable
communication.

II. On the Varieties of Cardoon, and the Methods of cultivating them. By
Mr. A. Mathews. ◊

Who does not wish to read of the cardoon; of that prince of vegetables,
whose praises have been sung or said by all cooks and gourmands, from the
fastidious Périgords and Cardellis of the French cuisine, down to the more
homely Rundells and Glasses of our English kitchens; whose virtues are so
marvellous as to be credible upon no less authority [p163] than that of the
sage gastrophilists aforesaid. To restore unwonted vigour to old age, and
new elasticity to youth, are the most modest of its attributes; the magical

broth with which the veins of Æson were replenished by the cunning
Medea, was doubtless prepared from the cardoon; and the story itself is
probably a sort of figurative record of the skill of the fair enchantress in
cooking this delicious vegetable, which was well known to the Grecian
gastronomes under the name of κακτος; but this we throw out merely as a
suggestion. Upon preparing herbs thus potent for the table, cookery has
exhausted all its skill; to dress a cardoon is declared, by the highest
authority in the art, to be the surest test of a skilful cook; and one of those
invaluable acquirements which, to borrow the words of a writer not less
celebrated for his powers of composition than of cooking, “raises cookery
to the rank of the sciences, and its professors to the title of artists.” Our
good forefathers, indeed, “could not find the true manner of dressing
cardoons,” and were content to eat them raw “with vinegar and oyl, pepper
and salt, all of them, or some, as every one liketh for their delight;” which,
considering that this vegetable is both bitter and astringent in a high degree,
does not argue much for the delicacy of palate of our ancestors; little did
they dream of the savoury preparations that modern art has devised by the
aid of Espagnole, consommé, blancs, tammies, marking, masking, and all
the mysteries of the stew-pan.
Four varieties are here described, of which the Spanish cardoon is the
most common, and the cardon de Tours the best.
They are cultivated, like celery, in deep broad trenches, well manured and
watered. When the plants are nearly full-grown, which will be about the end
of October, a dry day is to be chosen for performing the operation of
blanching them, which is thus effected:—
“The leaves of each plant are carefully and lightly tied together with strong matting, keeping the
whole upright, and the ribs of the leaves together. The plant is then bound closely round with twisted
haybands, about an inch and a half in diameter, beginning at the root, and continuing to about two-
thirds of its height. If the plants are intended for winter store, they must be earthed up like celery; but
if to be consumed before the frosts set in, the operation of earthing up may be omitted.” [p164]

III. Accounts and Descriptions of the several Plants belonging to the genus
Hoya, which are cultivated in the garden of the Horticultural Society at
Chiswick. By Mr. James Traill. ◊

The beauty of one species of Hoya, viz., H. carnosa, has long caused it to
be a favourite with collectors. The object of the writer of this paper is to call
attention to such others as are known to exist in gardens, or as are preserved
in the records of the botanist.
The following species form the subject of the paper, viz.:
1 Hoya carnosa, R. Brown. 2 Hoya crassifolia, Haworth. 3 Hoya
pallida, Lindley. 4 Hoya Pottsii, (Tab. I.) 5 Hoya trinervis.
These five are all the species at present cultivated in gardens; others are
known to exist in the warmer regions of Asia, where they should be
assiduously sought for by travellers, as they are not only very ornamental,
but easily to be transported to Europe.
From such materials as he has been able to procure, the writer
enumerates the following as completing the genus Hoya, as far as at present
ascertained:
6 Hoya chinensis. 7 Hoya viridiflora, R. Brown. 8 Hoya lanceolata,
D. Don. 9 Hoya linearis, D. Don. 10 Hoya australis, R. Brown,
MSS. 11 Hoya nicobarica, R. Brown, MSS. 12 Hoya augustifolia.
The paper concludes with a detailed explanation of the best manner of
cultivating Hoyas.

IV. On acclimatizing Plants at Biel, in East Lothian. By Mr. John Street,
gardener to the Honourable Mrs. Hamilton Nesbitt. ◊

Perhaps there is no point whatever, connected with Horticulture, of greater
interest than that which forms the subject of this paper; it is the distant goal
towards which we all are striving, but of which, alas! we have not as yet
even caught a glimpse. The gardener is in possession of the powers by
which he can bend the seasons to his will; he can dispel the frozen gloom of
winter with the rich warm glow of the vintage; at his call the flowers of
spring and summer start up beneath his feet, and his hothouses are filled
with the luscious fruits of the torrid zone. All this he knows how to effect

with an artificial climate; but he has no influence over the natural climate of
his country, nor can he impart to the vegetation of warmer latitudes the least
additional power of resisting cold, for which they have not been prepared
by nature. Acclimatizing is still a secret to be discovered. To [p165] this day
not a single instance can be adduced of any exotic plant whatever
possessing greater powers of withstanding cold, than it had when first
introduced. It has been hoped that if the seeds of given plant could be
procured, for many generations, in a climate severer than its own, the
offspring so obtained would gradually accommodate themselves to their
new country; but no such result has followed from the experiments that
have been tried. Let us take a few familiar examples:—the common
nasturtium, (Tropælum majus,) a native of Peru, is said to have been
introduced about the year 1686. At the time at which we are writing, it must
have descended through about 140 generations; and yet it has not become in
the smallest degree capable of resisting cold. Of the mignonette (Reseda
odorata), the date of introduction is not well ascertained; it has probably
been a favourite border annual for sixty or seventy years, and yet it has in
no degree shaken off its annual character, which is unnatural to it, and
resumed the suffrutescent habit which it possesses in its own milder
climate. The potato, too, which has for two centuries and a half been
increased in every conceivable manner, by seeds as well as by offsets, bears
cold in no degree more readily than it did in the sixteenth century. Nor does
it appear to us probable, that acclimatizing, if practicable, is to be brought
about by sowing seeds in northern latitudes through successive generations.
We do not believe that plants will bear their seeds at all in a temperature
much lower than that in which they have been located by the hand of
Nature. The heat of a northern summer sufficiently approximates to that of
the tropics, to be considered, with reference to vegetation, as the same, and
it is during that season that the seeds of all plants are ripened; the
conditions, therefore, under which the seeds of Tropæolum, for example,
are produced in England, do not materially differ from those under which
the same seeds are produced in Peru; if the season proves unpropitious in
any considerable degree, they are not produced at all. How then can it be

expected that seeds ripened under similar circumstances, but in different
latitudes, should give birth to a progeny differing in any remarkable
particular from their parents? In fact, in power of resisting cold, they do not
differ at all. If such a capability were to obtained, it would be by inducing
plants to ripen their seeds in winter.
But if it is certain that nothing is to be gained in acclimatizing, by raising
plants from seed through successive generations, [p166] it is no less true that
many trees, which have been supposed to be incapable of surviving a
northern winter, are now ascertained to be perfectly hardy, and that the
power of enduring cold may be increased in others, by a judicious
management of soil and situation.
The phenomenon of vegetable life being destroyed by cold, probably
arises from the vessels, through which the circulation and secretion of the
fluids of plants take place, being ruptured by the expansion, from cold, of
the fluid they contain. In proportion, therefore, to the tenuity of the vessels,
and the abundance of their fluid, will be the danger to which they are
exposed from frost; and to the strength of the vessels, and the paucity of
their fluid, the power of resisting cold. Thus vigorous shoots of the oak,
walnut, and many other trees, which are formed with rapidity, imperfectly
matured, and highly charged with fluid, are extremely impatient of cold,
and are even destroyed by a few degrees of frost; while the twigs and
branches of the same trees, which are formed slowly, fully matured, and
incompletely filled with fluid, bear unharmed the utmost rigour of our
winters. In acclimatizing, therefore, this law should be carefully
remembered, and the situations in which tender plants are stationed, should
be those in which their growth is restrained, and an excessive absorption of
fluid prevented.
This appears to have been the true secret of the success that has attended
the attempts at acclimatizing, which form the subject of Mr. Street’s
communication. By planting in situations well drained from superfluous
moisture, under circumstances where rapid growth was rendered
impracticable, and, as we understand, in a garden admirably adapted to the
object, from its position, he has succeeded in naturalizing, in latitude

56° N., plants which have not yet been known to endure the winters even of
the parallel of London.

V. Upon the Culture of Celery. By Thomas Andrew Knight, Esq., F.R.S.,
President. ◊

“That which can be very easily done, without the exertion of much skill or
ingenuity, is,” Mr. Knight observes, “very rarely found to be well done, the
excitement to excellence being in such cases necessarily very feeble.” This
remark is in the present case applied to the cultivation of celery, which,
being a native of the sides of wet ditches, might naturally be expected to
demand an abundant supply of water when cultivated. Accordingly, Mr.
Knight found that by keeping the ground, in which celery was planted, [p167]
constantly wet, it grew by the middle of September to the height of five
feet, and its quality was in proportion to its size. Mr. Knight also
recommends planting at greater distances than is usually the case, and
covering the beds, into which the young seedlings are first removed, with
half-rotten dung, overspread to the depth of about two inches with mould;
under which circumstances, whenever the plants are removed, the dung will
adhere tenaciously to their roots, and it will not be necessary to deprive the
plants of any part of their leaves.

VI. Report upon the New or Rare Plants which flowered in the Garden of
the Horticultural Society at Chiswick, between March, 1825, and March,
1826. Part 1. Tender Plants. By John Lindley, Esq. ◊

The subject of this paper consisting of botanical details which do not bear
curtailing, we shall only extract the names of the new species described in
it, as a guide to our botanical readers. In the whole, thirty-three species are
noticed; of which the following are published for the first time:—
2 Passiflora obscura. 7 Solanum dealbatum. 10 Tabernæmontana
gratissima. 13 Tephrosia? Chinensis. 15 Hellenia abnormis.

16 Gesneria Douglassii. 21 Gynandropsis pulchella. 23 Rodriguezia
planifolia. 26 Brassavola nodosa. 33 Phycella corusca.

VII. Account of a Protecting Frame for Fruit-Trees on Walls. By Mr. John
Dick. ◊

In order to protect the fruit upon walls from the ravages of bees, wasps,
flies, and other winged enemies, a frame is contrived fitting close to the
face of the wall, and having a moveable sliding canvass front, which can be
readily removed when the fruit is to be gathered, and replaced again
afterwards. A plan of the frame accompanies the paper. From what we have
seen of this contrivance, we know that it is well adapted to its purpose, and
that no garden in which fine fruit is required, should be without one or more
of such frames. For the mode of making them, we must refer to the paper
itself.

VIII. On the Esculent Egg-Plants. By Mr. Andrew Mathews. ◊

In this country, the egg-plant, brinjal, or aubergine, is chiefly cultivated as a
curiosity; but in warmer climates, where its growth is attended with less
trouble, it is a favourite article of the kitchen-garden. In the form of fritters,
or farces, or in soups, it is frequently brought to table in all the southern
parts of Europe; and forms a pleasant [p168] variety of esculent. This paper
describes the only two kinds that are worth cultivation in England.

IX. Notices of Communications to the Horticultural Society, between
January 1, 1824, and January 1, 1825. Extracted from the Minute Books
and Papers of the Society. ◊

A novel kind of pine pit is described, which is said to answer every purpose
that can be desired. It is heated by flues passing through a chamber, formed
by beams extending from the back to the front wall, and so becoming a sort

of floor, upon which is first placed a layer of turf; and then the tan in which
the pine-plants are plunged. The warmer air is conveyed into the upper part
of the pit by means of small apertures contrived in the walls, at four inches
and a half apart, both in the back and front of the pit, and also through iron
pipes resting on the beams and passing through the tan. The ventilation is
effected by air-holes in the front wall, and sliding shutters in the back walls.
An explanatory figure accompanies the statement.
The famous rhubarb, which has of late acquired so much celebrity under
the name of Buck’s rhubarb, is mentioned as excellent when forced. It is not
generally known, that this sort is the genuine Rheum undulatum of botanists
uncontaminated by mixture with the common garden kinds. The plant
generally called Rheum undulatum, is a half-bred, possessing none of the
good qualities of the native species.
George Tollet, Esq., of Betley Hall, in Staffordshire, recommends the
preservation of apples for winter store, packed in banks or hods of earth like
potatoes. The method is said to be effectual and economical.
Thomas Bond, Esq., of East Looe, in Cornwall, describes his mode of
cultivating strawberries. He does not adopt the common practice of cutting
off the runners, but they are confined to the bed by being turned back
among the plants from which they spring. In the autumn, the beds are
covered to the depth of two inches with fresh earth, through which the
strawberry plants shoot in the spring with great vigour.
A kind of wicker basket is described, which is cheap and well adapted for
screening half hardy plants during the winter. It is fixed in the earth by
means of the points of the ribs of the wicker work, which are allowed to
project a few inches for the purpose.
It is stated by John Wedgewood, Esq., that good celery may be readily
obtained by transplanting seedling plants that have remained in the seed
bed, till they had acquired a [p169] considerable size. They grow more
vigorously than the younger plants that are transplanted in the usual way.
William Cotton, Esq., of Wellwood-house, describes the good effects of
painting an old garden wall with seal oil and anticorrosion paint. The wall
in question was covered with trees, which were every year attacked by

blight. Since the operation the trees have borne good fruit, made healthy
wood, and been free from the bad consequences of blight.
Mr. John Mearns states, that the red and white Antwerp raspberries may
be brought to bear abundantly in August, long after the usual crop of
raspberries is past, by the following management. In May he removes the
young fruit, bearing shoots, from the canes, leaving in some cases one or
two eyes, in others, cutting them clean off. Under either plan, they soon
produce an abundance of vigorous new shoots, which blossom freely in
July.
Mr. Elias Hildyard, gardener to Sir Thomas Frankland, kills the grub
which infests his onion beds by trenching the beds in winter, digging in
manure at the same time, and leaving them exposed to the frost in a rough
state till the time of sowing.
A mode of inducing fertility in a barren Swan’s-egg pear-tree trained
upon a wall, is described by the Rev. John Fisher, of Wavenden, in
Buckinghamshire. It consists in twisting and breaking down the side shoots
of the main branches in such a way, as to make them pendulous without
separating them wholly from the parent limb. In a short time a grumous
formation takes place where the fracture has occurred, the wound heals, the
flow of the sap is moderated, and fruit buds are formed instead of sterile
shoots.
Mr. William Mowbray, gardener to the Earl of Mountnorris, states, that
the different species of eatable Passifloras which do not generally produce
fruit, may be induced to do so abundantly, if the pollen of other species is
applied to their stigmas.
Currants are preserved in perfection in the garden of James Webster,
Esq., of Westham, by being covered with bunting when the fruit is fully
ripe, care being had to unloose the bunting occasionally from the bottom of
the bushes, in order to remove the decaying fallen leaves.

X. Report on the Instruments employed in, and on the Plan of a Journal of
Meteorological Observations, kept in the garden of the Horticultural

Society at Chiswick. ◊

This and the following paper we propose to notice in detail on a future
occasion. [p170]

XI. Journal of Meteorological Observations made in the garden of the
Horticultural Society at Chiswick, during the year 1826. By Mr. William
Beattie Booth. ◊

XII. On Orache, its Varieties and Cultivation. By Mr. William Townshend.
◊

The herb orache was formerly cultivated as a kind of summer spinach; but
in this country it has long been expelled from the kitchen garden by other
kinds. It is, however, still seen in the gardens of France, where it is
commonly called Arroche des jardins, being used in that country, both by
itself as a spinach, and mixed with sorrel, the acidity of which it corrects.
Seven varieties are described, which do not differ in their qualities, but are
distinguished by the colour of their foliage.

XIII. On planting the moist Alluvial Banks of Rivers with Fruit-Trees. By
Mr. John Robertson. ◊

The object of this writer is to show that the low grounds that form the banks
of rivers are, of all others, the best adapted for the growth of fruit trees; the
alluvial soil of which they are composed, being an intermixture of the
richest and most soluble parts of the neighbouring lands, with a portion of
animal and vegetable matter, affording an inexhaustible fund of
nourishment. In such situations, however, the trees are liable to injury from
floods in the winter, unless some means are used of draining off the
stagnant water. This is to be effected by digging deep trenches between the
rows of trees, casting up the earth from the trenches around the trees on

either side, so as to form elevated banks. Such is the practice in Holland,
where the western slopes of the dykes are generally covered with fruit-trees,
chiefly apples and pears. Mr. Robertson is of opinion, that the banks should
be raised, if possible, at least three or four feet above the highest water-
mark, and be made eighteen feet broad at the base, and twelve at top; the
trenches should be fifteen or sixteen feet wide, admitting the soil to be three
or four feet deep.
Upon this plan, it is probable that abundant crops would be obtained; but
with regard to the quality of the produce, we suspect it will be quite as
indifferent as the apples and pears of the Dutch, which are notorious for
their want of flavour.

XIV. On Dahlias. By Mr. William Smith. ◊

This is an attempt to distinguish by words the best varieties of the Dahlia,
and to fix the names of those which are the most worthy of cultivation.
Sixty kinds are well described, [p171] arranged in divisions depending upon
the size of the plants and the colour of their flowers. We do not propose to
analyze this paper, which is far too extensive for our limits; but instead, to
throw together a few remarks which are suggested by the subject.
The first fact to which we would call attention has reference to
acclimatization. The Dahlia has now been cultivated in Europe with the
utmost assiduity for nearly thirty years. During that period millions of
plants have been raised from seeds, and under almost every possible
variation of climate; and anomalies the most singular, not only in colour,
but in general constitution and physiological structure, have been obtained.
The colour of the flower has been altered from pale yellow, or lilac, to every
hue of red, purple, or yellow, to pure scarlet and to deepest morone, or has
even been wholly discharged from the radial florets in the white varieties;
the period of flowering has been accelerated nearly two months; the tall
rank weed, exceeding the human standard in height, has been reduced to a
trim bush, emulating the pæony in dwarfishness; the yellow inconspicuous

florets of the disk have been expelled to make room for the showy deep-
coloured florets of the ray; what is more remarkable still, the same yellow
inconspicuous florets of the disk have been enlarged, and stained with rich
morone, so as to rival the colours of the ray without losing their own
peculiarity of form; and finally, the whole foliage and bearing of the plant
has been altered by the substitution of simple leaves for compound ones.
But notwithstanding all this proneness to change, notwithstanding the
multitude of varieties which have been thus procured by seed, not one
individual has yet been discovered, in any degree whatever, more hardy
than its ancestors. The earliest frosts destroyed the Dahlias as certainly in
1826, as they could have done in 1789.
But, however strong may be the disposition of the Dahlia to vary from its
original structure, it is curious to observe how strictly it conforms to the
laws by which such variations are controlled by nature. In altered structure
all the changes take place from circumference to centre. The florets of the
ray displace those of the disk, but the latter never attempt to occupy the ray;
when a change occurs among the florets of the disk, they merely dilate and
assume the colour of the ray, without changing their position or their
peculiar form. So with the leaves; by a reduction of the lateral leaflet, till
the terminal one only remains, simple foliage is substituted for that which
was compound: but no case has been found in [p172] which the suppression
of the terminal leaflet has taken place and the lateral ones have been
preserved. In change of colour, too, there is a circumstance which demands
consideration, and of which no explanation has yet been offered. It is not
generally known, although long ago noticed by M. De Candolle, that among
flowers, yellows will not produce blues, nor blues yellows, although both
these primitive colours will sport into almost every other hue. Thus the
hyacinth, the natural colour of which is blue, will not produce a yellow, for
the dull, half-green flowers called yellow hyacinths, are, in our judgment,
whites approaching green; the blue crocus will not vary into yellow, nor the
yellow into blue; and the ranunculus and the dahlia, the natural colour of
both which, notwithstanding the popular belief to the contrary, with respect
to the dahlia, is, we believe, yellow, although they are the most sportive of

all the flowers of the gardens, varying from pink to scarlet, and deepest
shades of purple, have never yet been seen to exhibit any disposition to
become blue. This subject offers a most amusing field for investigation, and
would well repay the attentive consideration of the philosopher.

XV. On the Cultivation of Camellias in an open Border. By Mr. Joseph
Harrison. ◊

Mr. H. finds that the double red camellia, the double white, and the double
striped, will bear an English winter if planted out when about two feet high,
having been previously stunted in their growth by repeatedly stopping their
leading shoots. For two winters the young plants are to be protected by a
wooden screen fixed round them, and covered by a hand-glass, the whole
being enveloped in mats; afterwards they require no other protection than to
be guarded from heavy snowstorms, and to be assisted by a thick covering
of old tan upon the ground in which they grow, to the distance of two or
three feet from their stems. If this success has been met with in Yorkshire,
what may not be expected in our more southern counties! On the 12th of
March of the present year these camellias were not injured by a frost which
did considerable damage to the common laurel.

XVI. A Method of growing Crops of Melons on open Borders. By Mr.
William Greenshields. ◊

The sorts fitted for this purpose are the black rock, scarlet rock, green-
fleshed, netted and early Cantaloup melons. The method consists of forming
a bed, by half filling a shallow [p173] trench with decayed vegetables, and
covering them with the exhausted linings of cucumber beds. The young
plants are reared for some time under handlights. For full particulars of this
practice, we must refer to the paper itself, which is clearly written, and,
coming as it does from one of our most skilful gardeners, well worthy of
attention.

XVII. Notice of Five Varieties of Pears received from Jersey in the year
1826. By John Lindley, Esq. ◊

The fruits here described are of the highest excellence. They are, 1. the
Marie Louise; 2. the Duchesse d’Angoulême; 3. the Doyenné gris; 4. the
Doyenné panaché; 5. the Beurré d’Aremberg; and 6. the Gloux morceaux.
The second, the fifth, and the sixth kinds are represented in two very
beautiful coloured plates; and are, perhaps, the most exquisitely flavoured
of all the varieties of the pear. The Beurré d’Aremberg and Gloux morceaux
are long keepers; the others are autumnal kinds. Of the former it is said,
“the flesh is whitish, firm, very juicy, dissolves in the mouth, and is wholly
destitute of grittiness; it is sweet, rich, and so peculiarly high flavoured, that
I know no pear that can be compared with it in that respect.”

XVIII. Upon the Culture of the Prunus Pseudo-cerasus, or Chinese
Cherry. By Thomas Andrew Knight, Esq. ◊

This species of cherry is expected to become an acquisition of considerable
value, for the purpose of forcing; and also as an early fruit, when trained
upon an open wall. Mr. Knight recommends its propagation by cuttings,
which root freely, and that it be abundantly supplied with liquid manure.
From its highly excitable habits, he suspects it to be a native of a cold
climate, probably of Tartary.

XIX. On the Culture of the Pine-Apple. By Mr. James Dall.

XX. On forcing Asparagus. By the same. ◊

These two papers were communicated by the Cambridge Horticultural
Society, having gained one of the annual silver medals presented by the
London to Provincial Societies. They contain good practical directions for
the cultivation upon which they treat.

XXI. Observations upon forcing Garden Rhubarb. By Mr. William
Stothard. ◊

This plan is perhaps the best that can be followed, as it is at once the most
certain and the most simple. You sow rhubarb seed on a rich moist border in
the beginning of April, [p174] The young plants are well thinned during the
summer; in the end of October they are very carefully transplanted into
forcing-pots, five or six in each pot. They are placed in a north aspect, to
recover the effect of their removal from the seed-bed, and in a month they
are fit for forcing. We can safely recommend this method.

XXII. Account of some remarkable Holly Hedges and Trees in Scotland.
By Joseph Sabine, Esq. ◊

This is in elaborate account of extraordinary specimens of hollies, and
appears to have been written with a view to induce the more general
cultivation in this country of that very valuable tree. At Tynningham, the
residence of the Earl of Harrington, are hedges extending to no less a
distance than 2952 yards, in some cases thirteen feet broad, and twenty-five
feet high. The age of these hedges is something more than a century. At the
same place are individual trees of a size quite unknown in these southern
districts. One tree measured five feet three inches in circumference at three
feet from the ground; the stem is clear of branches to the height of fourteen
feet, and the total height of the tree is fifty-four feet. The other places at
which the hollies are of unusual size, are Colinton-house the seat of Sir
William Forbes; Moredun, the seat of David Anderson, Esq.; Hopetoun-
house, the seat of the Earl of Hopetoun, and Gordon-castle, where are
several large groups of hollies, apparently planted by the hand of Nature.

XXIII. An Account of a Plan of Heating Stoves by means of Hot Water,
employed in the Garden of Anthony Bacon, Esq. ◊

We conceive that a new æra in horticulture will commence with the
publication of this paper. We already possessed contrivances of a
sufficiently good kind for all purposes connected with artificial climate,
except the power of commanding heat; for which the two methods hitherto
employed have been either too clumsy or too costly, and in either case
liable to numerous objections. The old mode of introducing heat into a
stove, by means of brick flues, has long been considered so bad, that every
scheme that promised to supersede such flues has been hailed with joy; the
uncertainty of the quantity of heat given out by a brick flue, its continual
liability to explosion, the impossibility of preventing the escape of smoke
from between the joints of the bricks, are all evils that require a remedy. For
this purpose steam was introduced, and with great advantage in extensive
ranges of hothouses. But the enormous expense of erecting a steam [p175]
apparatus, the danger attending its use in the charge of an unskilful or
careless gardener, and also the rapid loss of heat from the pipes upon any
neglect of the boiler, have all contributed to prevent the use of steam
becoming very general. The plan now described has the great merit of
possessing all the good qualities of steam, without any of its objectionable
accompaniments; its cost cannot in any considerable degree exceed that of
flues, and its effects are so certain and durable, that a house so heated may
be almost said to be beyond the power of neglect on the part of the
gardener.
Without entering into the details of this plan, for which we must refer to
the paper itself, we shall content ourselves with explaining its principle.
Suppose two iron reservoirs, A and B, of equal capacity, placed twenty feet
apart, and connected at the top and the bottom by iron pipes, the level of
both reservoirs being the same; it is obvious that water poured into one of
these reservoirs will flow into the other through the connecting pipes, and
that it will consequently stand at the same height in both. Let the reservoirs
be thus filled above the level of the uppermost pipe, and heat be applied to
the bottom of one reservoir, A; the water in this will presently be forced
through the upper pipe into the reservoir, B, of water not heated; in
proportion as the heated water flows out of A, through the upper pipe, the

cold water will flow out of B through the lower pipe; and by this means a
circulation of water heated and water to be heated will be formed, which
will continue as long as the application of fire to the bottom of one reservoir
is continued. When it is discontinued, the temperature of the two reservoirs
and of the intermediate pipes will be the same within three or four degrees.
As it is the property of heated water to part with its heat very slowly, it
follows that heat will continue to be disengaged from the reservoirs and
pipes long after the application of fire has ceased. In fact, when the two
reservoirs are once heated, the gardener may make up his fires and retire to
rest, certain that his house is sufficiently provided with heat for the night.
The paper is accompanied with a plan of a vinery warmed upon this
principle. [p176]

On the Recent Elucidations of early Egyptian History. ◊

S INCE the commencement of the present century, the researches of
philologists have ascertained that the language of ancient Egypt,—the
language of the hieroglyphical inscriptions engraven on its ancient temples
and monuments, and of the still existing manuscripts of the same period,—
differs from the modern Egyptian or Coptic, only in the mixture in the latter
of many Greek and Arabian and a smaller portion of Latin words,
introduced during the successive dominion of the Greeks, the Romans, and
the Arabs, and occasionally substituted for the corresponding native words.
The grammatical construction of the language has remained the same at all
periods of its employment: and it finally ceased to be a spoken language
towards the middle of the seventeenth century, when it was replaced by the
Arabian.
In writing their language, the ancient Egyptians employed three different
kinds of characters. First, figurative; or representations of the objects
themselves. Second, symbolic; or representations of certain physical or
material objects, expressing metaphorically, or conventionally, certain

ideas; such as, a people obedient to their king, figured, metaphorically, by a
bee; the universe, conventionally, by a beetle. Third, phonetic, or
representative of sounds; that is to say, strictly alphabetical characters. The
phonetic signs were also portraits of physical and material objects; and each
stood for the initial sound of the word in the Egyptian language which
expressed the object pourtrayed: thus a lion was the sound L, because a lion
was called Labo; and a hand a T, because a hand was called Tot. The form
in which these objects were presented, when employed as phonetic
characters, was conventional, and definite to distinguish them from the
same objects used either figuratively or symbolically; thus, the conventional
form of the phonetic T was the hand open and outstretched; in any other
form the hand would either be a figurative, or a symbolic sign. The number
of distinct characters employed as phonetic signs appears to have been
about 120; consequently many were homophones, or having the same
signification. The three kinds of characters were used indiscriminately in
the same writing, [p177] and occasionally in the composition of the same
word. The formal Egyptian writing, therefore, such as we see it still existing
on the monuments of the country, was a series of portraits of physical and
material objects, of which a small proportion had a symbolic meaning, a
still smaller proportion a figurative meaning, but the great body were
phonetic or alphabetical signs: and to these portraits, sculptured or painted
with sufficient fidelity to leave no doubt of the object represented, the name
of hieroglyphics, or sacred characters, has been attached from their earliest
historic notice.
The manuscripts of the same ancient period make us acquainted with two
other forms of writing practised by the ancient Egyptians, both apparently
distinct from the hieroglyphic, but which, on careful examination, are found
to be its immediate derivatives; every hieroglyphic having its corresponding
sign in the hieratic, or writing of the priests, in which the funeral rituals,
forming a large portion of the manuscripts, are principally composed; and in
the demotic, called also the enchorial, which was employed for all more
ordinary and popular usages. The characters of the hieratic are for the most
part obvious running imitations, or abridgments of the corresponding

hieroglyphics; but in the demotic, which is still further removed from the
original type, the derivation is less frequently and less obviously traceable.
In the hieratic, fewer figurative or symbolic signs are employed than in the
hieroglyphic; their absence being supplied by means of the phonetic or
alphabetical characters, the words being spelt instead of figured; and this is
still more the case in the demotic, which is, in consequence, almost entirely
alphabetical.
After the conversion of the Egyptians to Christianity, the ancient mode of
writing their language fell into disuse; and an alphabet was adopted in
substitution, consisting of the twenty-five Greek letters, with six additional
signs expressing articulations and aspirations unknown to the Greeks, the
characters for which were retained from the demotic. This is the Coptic
alphabet, in which the Egyptian appears as a written language in the Coptic
books and manuscripts preserved in our libraries; and in which,
consequently, the language of the inscriptions on the monuments may be
studied. [p178]
The original mode in which the language was written having thus fallen
into disuse, it happened, at length, that the signification of the characters,
and even the nature of the system of writing which they formed, became
entirely lost; such notices on the subject as existed in the early historians
being either too imperfect, or appearing too vague, to furnish a clue,
although frequently and carefully studied for the purpose. The repossession
of this knowledge will form, in literary history, one of the most remarkable
distinctions, if not the principal, of the age in which we live. It is due
primarily to the discovery by the French, during their possession of Egypt,
of the since well-known monument called the Rosetta Stone, which, on
their defeat and expulsion by the British troops, remained in the hands of
the victors, was conveyed to England, and deposited in the British Museum.
On this monument the same inscription is repeated in the Greek and in the
Egyptian language, being written in the latter both in hieroglyphics and in
the demotic or enchorial character. The words Ptolemy and Cleopatra,
written in hieroglyphics, and recognized by means of the corresponding
Greek of the Rosetta inscription, and by a Greek inscription on the base of

an obelisk at Philæ, gave the phonetic characters of the letters which form
those words: by their means the names were discovered, in hieroglyphic
writing, on other monuments of all the Grecian kings and Grecian queens of
Egypt, and of fourteen of the Roman emperors ending with Commodus; and
by the comparison of these names one with another, the value of all the
phonetic characters was finally ascertained.
The hieroglyphic alphabet thus made out has been subsequently applied
to the elucidation of the earlier periods of Egyptian history, particularly in
tracing the reigns and the succession of the Pharaohs, those native princes
who governed Egypt at the period of its splendour; when its monarchy was
the most powerful among the nations of the earth; its people the most
advanced in learning, and in the cultivation of the arts and sciences; and
which has left, as its memorials, constructions more nearly approaching to
imperishable, than any other of the works of man, which have been the
wonder of every succeeding people, and which are now serving to re-
establish, at the expiration of above 3000 years, the details of [p179] its long-
forgotten history. To trace these stupendous monuments of art to their
respective founders, and thus to fix, approximatively, at least, the epoch of
their first existence, is a consequence of the restoration of the knowledge of
the alphabet and the language of the inscriptions engraven on them. We
propose to review, briefly as our limits require, the principal and most
important facts that have thus recently been made known in regard to those
early times; and shall deem ourselves most fortunate if we can impart to our
readers but a small portion of the interest which we have ourselves derived
in watching their progressive discovery.
The following are the authors to whom we are chiefly indebted for the
few particulars we know of early Egyptian history. Herodotus and Diodorus
Siculus, Grecians, and foreigners in Egypt. Manetho, a native; and
Eratosthenes, by birth a Cyrenean, a province bordering on Egypt, both
residents. Josephus, a Jew, and Africanus, Eusebius, and Syncellus,
Christians, Greek authors. Herodotus visited Egypt four centuries and a half
before Christ, and within a century after its conquest by the Persians. In his
relation of the affairs of the Greeks and Persians, he has introduced

incidentally a sketch of the early history of Egypt, such as he learnt it from
popular tradition, and from information obtained from the priests. It is,
however, merely a sketch, particularly of the earlier times; and is further
recorded by Josephus to have been censured by Manetho for its
incorrectness. Diodorus is also understood to have visited Egypt about half
a century before Christ; and from him we have a similar sketch to that of
Herodotus; a record of the names of the most distinguished kings, and for
what they were distinguished; but with intervals, of many generations and
of uncertain duration, passed without notice. Manetho was a priest of
Heliopolis in Lower Egypt, a city of the first rank amongst the sacred cities
of ancient Egypt, and long the resort of foreigners as the seat of learning
and knowledge. He lived in the reign of Ptolemy Philadelphus, two
centuries and a half before Christ, and wrote, by order of that prince, the
history of his own country in the Greek language, translating it, as he states
himself, out of the sacred records. His work is, most unfortunately, lost; but
the fragments which have been preserved to us, by the writings [p180] of
Josephus in the first century of the Christian æra, and by the Greek authors
above named of the third and fourth centuries, contain matter, which, if
entitled to confidence, is of the highest historical value, viz., a chronological
list of the successive rulers of Egypt, from the first foundation of monarchy,
to Alexander of Macedon, who succeeded the Persians. This list is divided
into thirty dynasties, not all of separate families; a memorable reign
appearing in some instances to commence a new dynasty, although
happening in the regular succession. It originally contained the length of
reign as well as the name of every king; but in consequence of successive
transcriptions, variations have crept in, and some few omissions also occur
in the record, as it has reached us through the medium of different authors.
The chronology of Manetho, adopted with confidence by some, and
rejected with equal confidence by others,—his name and his information
not being even noticed by some of the modern systematic writers on
Egyptian history,—has received the most unquestionable and decisive
testimony of its general fidelity by the interpretation of the hieroglyphic
inscriptions on the existing monuments: so much so, that by the accordance

of the facts attested by these monuments with the record of the historian, we
have reason to expect the entire restoration of the annals of the Egyptian
monarchy antecedent to the Persian conquest, and which, indeed, is already
accomplished in part.
Before we pursue this part of our subject, we must conclude our brief
review of the original authorities in early Egyptian history, by a notice of
Eratosthenes. He was keeper of the Alexandrian library in the reign of
Ptolemy Evergetes, the successor to Ptolemy Philadelphus, under whose
reign Manetho wrote. Amongst the few fragments of his works, which have
reached us transmitted through the Greek historians, is a catalogue of thirty-
eight kings of Thebes, commencing with Menes, (who is mentioned by the
other authorities also as the first monarch of Egypt,) and occupying by their
successive reigns 1055 years. These names are stated to have been compiled
from original records existing at Thebes, which city Eratosthenes visited
expressly to consult them. The names of the two first kings in his catalogue
are the same with the names of the two first kings of the first dynasty of
Manetho; but the [p181] remainder of the catalogue presents no further
accordance, either in the names or in the duration of the reigns.
To return to Manetho:—amongst the monarchs of the original Egyptian
race there was one named by him Amenophis, (the eighth king of the
eighteenth dynasty,) of whom it is stated, in a note of Manetho’s preserved
by Syncellus, that he was the Egyptian king whom the Greeks called
Memnon. The statue of Memnon at Thebes, celebrated through all antiquity
for the melodious sounds which it was said to render at sunrise, is identified
in the present day by a multitude of Greek inscriptions; one of which, in
particular, records the attestation of Publius Balbinus, who visited the ruins
of Thebes in the suite of the empress the wife of Adrian, to his having
himself heard the “divine sounds of Memnon or Phamenoph;” which latter
name is Amenophis, with the Egyptian masculine article φ prefixed, and
omitting the Greek termination. The hieroglyphics carved on the statue, and
coeval with its date, had been very carefully copied by the French whilst in
possession of Egypt, and were engraved in the splendid work, the
Description de l’Egypte, to which their researches had given rise. These

hieroglyphics contain the alphabetic characters Amnf (being the initial
vowel and all the consonants of the name Amenof) inclosed within a ring; a
distinction which had been previously observed to take place with the
names of the Roman emperors, and of the Grecian kings and queens; and as
the rings have hitherto been found to occur in no other instance whatsoever
than when containing the names and titles of sovereigns, they are regarded
as characteristic signs. It should be remarked, that in the hieroglyphic
writing, as in the languages of other eastern nations most nearly connected
with Egypt, the vowels are often omitted, and when expressed, have not
always a fixed sound. The coincidence of the reading of the hieroglyphic
name with that recorded by Manetho, and with the Greek inscription on the
statue itself, was so far confirmatory of Manetho’s authority; it was also
highly interesting in the evidence it afforded of the employment of the same
hieroglyphic alphabet, that was in after use in the times of the Ptolemies
and the Cæsars, even in the very early periods of the Egyptian monarchy;
for the reign of Amenophis was in the dynasty preceding that of Sesostris: it
also indicated the further [p182] advantage to be gained by the application of
the alphabet in decyphering other proper names, distinguished by being
inclosed in rings, existing on other statues, and in the more ancient temples
generally. Considerable progress had been made in reading these, which in
several instances had been found to correspond with the names of the kings
of the same and of subsequent dynasties to Amenophis, as given by
Manetho, when a most important discovery was made of the existence of a
genealogical record, in hieroglyphics, of the titles of thirty-nine kings
anterior to Sesostris, chronologically arranged. We have already noticed that
the names and titles of kings were distinguished by being inclosed in rings;
the ring containing the proper name being accompanied usually by a
second, inclosing certain other hieroglyphics, expressing the title by which
that particular king was designated; and it appears probable that the kings of
Egypt were distinguished by their titles rather than by their names, since the
same name recurs frequently in different individuals, but the titles are all
dissimilar; with a single exception amongst the very many that have come
under observation, and in which the same title is common to two brothers.

The signification of the titles is yet obscure, except that they are of the same
general nature as is frequent in the East, such as “Sun of the Universe,” &c.;
but for the purpose of individualizing, the sign is to us of the same value as
the thing signified; and as other monuments furnish the names in connexion
with the titles, we are enabled to compare the succession evidenced by the
titles with the record of the historian, and thus to test the fidelity of the
record. The discovery of this hieroglyphic table was made by Mr. William
Banks in 1818, in excavating for the purpose of obtaining an accurate
ground-plan of the ruins of Abydus, near Thebes. On a side wall of one of
the innermost apartments, hieroglyphics were sculptured inclosed in rings,
ranged symmetrically in three horizontal rows, each row having originally
contained twenty rings, of which twelve of the upper row, eighteen of the
middle, and fourteen of the lower row were still remaining, the others
having been destroyed by the breaking down of the wall. The hieroglyphics
having been copied and lithographed, it was speedily recognised that the
rings in the two upper rows consisted of titles only; with the exception of
one [p183] proper name, the last of the second row, since known to be the
name of the king whose title is the last in the succession, and who was the
fourth in reign and generation before Sesostris. The third row was
recognised to consist of one proper name and one title, each repeated ten
times, and alternating with each other: these are since known to be the name
and title of Sesostris, to whose reign the construction of the table is with
much probability ascribed. The titles in the same row with that of the
ancestor of Sesostris and preceding it, have been identified on other
monuments, coupled with names which are those of the predecessors of the
same king in the list of Manetho.
It would exceed our limits, and it is not our purpose, to trace in detail the
successive steps by which the existence of each of the kings of Manetho’s
list, from the expulsion of the Phœnician shepherds from Lower Egypt, and
the consequent union of Upper and Lower Egypt in a single monarchy, to
the reign of Sesostris, has been attested by the monuments. Suffice it to say,
that the same number of individuals as stated by Manetho, namely,
eighteen, filling a space of four centuries, are shown, by the monuments, to

have reigned in that interval, and to have borne the same relationship, as
well as succession, to each other, as is expressed by the historian: that, of
the eighteen names, eight in different parts of the list are read on the
monuments identically as in the historical record; and that in regard to the
names that are not identical, we have the testimony of Manetho that some
amongst the kings, Sesostris, for example, were known by two and even by
more names. The table of Abydus appears to have been strictly a
genealogical record; a record of generations, in which view it is strictly
accordant with the historian.
The period of the Egyptian annals on which this light has been thrown, is
precisely that which might have been selected in the whole history of Egypt
as the most desirable for such purpose. Independently of its very high
antiquity, it was the period of the greatest splendour and power of the native
Egyptian monarchy, and of the highest (Egyptian) cultivation of the arts.
The greater part of the more ancient, and by far the most admirable in
execution, of the temples, palaces, and statues, which still attest by their
ruins their former magnificence, are the work of that age; and the
hieroglyphic inscriptions still [p184] extant on them, and which, when not
defaced by wanton injury, are almost as perfect as when first executed,
make known the reigns in which they were respectively constructed, and
frequently the purposes for which they were designed. This is in itself no
small achievement, when we reflect that these extraordinary remains of
ancient art were equally the objects of vague wonderment in the times of
the Roman emperors, as they were in those of the generation preceding
ourselves; but that they are become to us objects of a more enlightened
curiosity, which they promise amply to repay, when the study that has
already made known their founders, shall reveal the signification of the
hieroglyphic histories, with which the walls of the palaces and temples are
covered. Already have we gained some very important facts in regard to the
condition, political and otherwise, of the countries adjoining to Egypt at that
early period. The monuments of Nubia are covered with hieroglyphics,
perfectly similar both in form and disposition to those on the edifices at
Thebes; the same elements, the same formulæ, the same language; and the

names of the kings who elevated the most ancient amongst them, are those
of the princes who constructed the most ancient parts of the palace of
Karnac at Thebes. As far as Soleb on the Nile, 100 leagues to the south of
Philæ the extreme frontier of Egypt, are found constructions bearing the
inscriptions of an Egyptian king; evidencing that, during the period of
which we have been treating, Nubia was inhabited by a people having the
same language, the same belief, and the same kings as Egypt. To the south
of Soleb, and for more than 100 leagues in ascending the Nile, in ancient
Ethiopia, very recent travellers have discovered the remains of temples, of
the same general style of architecture as those of Nubia and Egypt,
decorated in the same manner with hieroglyphics representing the same
mythology, and analogous to those of Egypt in the titles, and in the mode of
representing the names and titles, of the sovereigns. But the proper names
of the kings inscribed on the edifices of Ethiopia in phonetic characters,
have nothing in common with the proper names of the Egyptian kings in the
dynasties of Manetho; nor is one of the Ethiopian names found either on the
monuments of Nubia or of Egypt. Thus there was a time when the civilized
part of Ethiopia,—Meroe, and the banks [p185] of the Nile between Dongola
and Meroe,—were inhabited by a people having language, writing, religion,
and arts similar to Egypt; but, in political dominion, independent of that
country, and ruled by kings of whom it does not appear that any historical
record whatsoever has come down to us.
The dates of the expulsion of the Phœnican shepherds from Egypt, and of
the reign of Sesostris, in years of the æra of our computation, have been
favourite subjects of discussion with chronologists: Archbishop Usher fixed
the former of these events in the year B. C. 1825; which would make the
commencement of the reign of Sesostris about B. C. 1483. The reign of
Sesostris is connected with the early Grecian chronology by the migration
of Danaus, brother of Sesostris, who, according to the Parian marbles,
arrived in Greece in 1485, which is a very few years earlier than the dates
of Usher would assign to that event. M. Champollion Figeac, brother of the
M. Champollion to whom the greater part of the discoveries made by the
interpretation of hieroglyphics are owing, himself a distinguished

chronologist, has assigned the year B.C. 1822 to the expulsion of the
Phœnicians, which Usher had placed in 1825: the date of M. Champollion
being derived from Manetho’s statement, that the Phœnician invasion took
place in the 700th year of the Sothiacal period, viz., B.C. 2082, and that
their dominion in Egypt continued 260 years. Historical accuracy may make
it desirable, that the exact year of the most ancient as well as of more
modern events should be determined, if it be possible: but for purposes of
general interest, and especially for comparison with the chronology of
cotemporary nations, which at that early period is in every case more
unsettled than the Egyptian, the period seems sufficiently determined. The
date before Christ 1822, pursued downwards through the dynasties of
Manetho, conducts with very close approximation to the known period B.C.
525 of the conquest of Egypt by the Persians; and intermediately, accords
very satisfactorily with the dates, according to the Bible chronology, of the
conquest of Jerusalem in the reign of Jeroboam by Shishak, king of Egypt,
and of Tirhakah, king of Ethiopia and Egypt, who made war against
Sennacherib; these are the Sesonchis of Manetho, and Sh.sh.n.k of
hieroglyphic inscriptions on a temple at Bubaste, and on one of the courts
of the [p186] palace at Karnac,—and the Taracus of Manetho, and T.h.r.k of
hieroglyphic inscriptions existing in Ethiopia and in Egypt33.
In respect to the connexion of the events of the Jewish and Egyptian
histories, the period between the expulsion of the Phœnicians and the reign
of Sesostris possesses a peculiar interest, as being that of the residence of
the Israelites in Egypt, and of the Exodus. In the history of Josephus, we
have an extract from Manetho, in which this latter event is expressly stated
to have taken place under the father of Sesostris, a king whose name, in
Manetho’s list, is Amenophis, (the third of that name,) and on the
monuments Ramses. The date which chronologists are generally agreed in
assigning to the Exodus is 1491; that of the termination of the reign of
Amenophis, according to Champollion, is 1473, or, if the correction of his
chronology which we have suggested in a note be just, 1478: it is singular
that the difference of thirteen years (between 1491 and 1478) should be
precisely the duration of a very suspicious interval which Manetho states to

have taken place, after Amenophis had gone with his army in pursuit of the
Israelites; and during which interval neither the king nor his army returned
to [p187] Egypt, but are stated to have been absent in Ethiopia. If the Exodus
occurred during the reign of any of the kings of the eighteenth dynasty, it
could only have been in the reign of the immediate predecessor of Sesostris;
since his conquests in Phœnicia, and his expeditions against the Assyrians
and Medes, must have brought him in contact with the Israelites, had they
been then residing in the Holy Land, so as at least to have caused some
mention to have been made in their history of the passages of so great a
conqueror. But presuming Amenophis, father and predecessor of Sesostris,
to have been the Pharaoh of the Exodus, the wandering of the Israelites in
the desert for forty of the fifty-five years ascribed to the reign of Sesostris,
is a sufficient explanation of his being unnoticed in the Jewish history;
whilst the fact of that nation having been subject to the Egyptians during the
reign of Ousirei, commencing 124 years before the death of Amenophis, is
attested by the paintings on the wall of one of the chambers of the tomb of
that king, discovered by Belzoni, and with which we are so well acquainted
by means of the model exhibited in England.
Whilst recalling to recollection the peculiar physiognomy of the Jews
pourtrayed in that tomb,—and which is as characteristic of their present
physiognomy as if it had been painted in the present age, instead of above
3000 years ago,—the equally well characterized, but very different
physiognomy of the Phœnician shepherds, represented on the monuments
of the same period, is decisive of the error of Josephus, who imagined the
Jews and the Shepherds to be the same people. The Phœnician shepherds,
long the inveterate enemy of the Egyptians, form a leading feature as
captives, in the representations of the exploits of the monarchs who
conducted the warfare against them. These people are always painted with
blue eyes and light hair; and it is not a little curious to see assembled on the
wall of the same apartment, different races, so distinctly characterised as the
Jew, the Phœnician, the Egyptian, and the Negro; the latter in colour, and in
the outline of the features, in painting and in sculpture, precisely as at
present; all, moreover, inhabitants of countries not very distant from each

other, and at a period when not more than twelve or thirteen centuries had
passed since all these races had descended from a single parent. In the
writings which attempt to explain from natural causes [p188] the diversity of
race amongst mankind, much power has been ascribed to the effects of time
and climate: but the facts with which we are now becoming better
acquainted than before, do not appear to admit of explanation from those
circumstances. It is worthy of notice that the negro, and the light-haired and
blue-eyed people, the two races who might be deemed at the greatest
distance apart amongst the varieties of man, are, equally with the
intermediate Egyptians, the descendants of Ham.
Of the succession of kings in Manetho’s chronology, from Sesostris to
the Persian conquest, a space of nine centuries and a half, about one half the
names have been already identified on different monuments: four of the
Persian monarchs, subsequent to the conquest, have also been traced in
inscriptions in phonetic characters; their names are written, as nearly as can
be spelt with our letters, Kamboth, (Cambyses); Ntariousch, (Darius);
Khschearscha, (Xerxes); and Artakschessch, (Artaxerxes.)
The ascent by monumental evidence to yet more remote antiquity than
the expulsion of the Phœnician shepherds, (B.C. 1822), is not altogether
without hope, notwithstanding the general demolition of the temples of the
gods, which took place according to Manetho, during the long dominion of
the Phœnicians in Egypt. We learn from the Description de l’Egypte that
even the most ancient structures at Thebes are themselves composed of the
debris of still more ancient buildings, used as simple materials, on which
previously sculptured and painted hieroglyphics are still existing; these are
doubtless the remains of the demolished temples, but the inscriptions will
require to be studied on the spot. There is also reason to believe, that there
exists amongst the ruins of the palace of Karnac, a portion of still more
ancient construction than the palace itself; which, having escaped
demolition, was incorporated with the more recent building. The
inscriptions on this apparently very ancient ruin present the name and title
of a king, which form a very interesting subject for future elucidation. The
title does not accord with any one now extant on the table of Abydus, but

possibly may have been one of those which were destroyed with a portion
of the wall, and which are of kings of earlier date than the expulsion of the
shepherds. The name is Mandouei, which name occurs in the dynasty
anterior to Sesostris, but coupled [p189] with a different title, an effectual
distinction; nor does the name recur in any subsequent dynasty. M.
Champollion Figeac has, with much ingenuity, shown the probability of the
identity of the Mandouei of the ancient ruin with the Osymandyas, Ousi-
Mandouei, mentioned by Diodorus Siculus as an Egyptian king greatly
distinguished by his conquests, whose reign M. Champollion infers, from
the historical passages relating to him, to have commenced 190 years before
the Phœnician invasion, or B.C. 2272 years; a prodigious antiquity, and of
the very highest interest should it be established, since there exist of this
individual no less than three statues in European collections, distinguished
by the same name and title: two of these are colossal, one at Turin, and a
second at Rome: a third is in the British Museum; and as all particulars
must interest which relate to a statue, of which there is at least probability
that is the most ancient existing in the world,—the date attributed to it being
earlier than the birth of Abraham,—we copy from Burckhardt the following
short description of its discovery: “Within the inclosure of the interior part
of the temple at Karnac, Belzoni found a statue of a hard, large-grained
sandstone: a whole length naked figure sitting upon a chair with a ram’s
head upon the knees: the face and body entire; with plaited hair falling
down to the shoulders. This is one of the first, I should say, the first
Egyptian statue I have seen: the expression of the face is exquisite, and I
believe it to be a portrait.”—(J. L. B URCKHARDT , Travels in Nubia, lxxvii.
Letter to Mr. W. Hamilton, 20th February, 1817.)—This statue is in the
farthest corner on the right hand side after entering the gallery of the
Egyptian antiquities in the British Museum; and compared with other
statues in the same gallery, which are of kings of the eighteenth dynasty, the
dissimilarity of the features from the very characteristic ones of the latter
family is too striking to be questioned. The problem of the age of this king
Mandouei is, at all events, a highly curious one; and will probably receive
its solution amongst the many other valuable discoveries which cannot fail

to result from M. Champollion’s projected visit to Egypt, in which he will
be accompanied by the sincere good wishes of every one in every country,
who feels an interest in the restoration of authentic history. E. S.

33 It appears to us that a slight inaccuracy has crept into the deduction of all the dates in M.
Champollion’s Chronology subsequent to the expulsion of the shepherds. The date of that event
is the foundation of the subsequent dates, and is supposed to have taken place B.C. 1822; after
which, according to the extract of Manetho in Josephus cited by M. Champollion, Thoutmosis,
the king by whom they had been expelled, reigned 25 years and 4 months, followed by the other
kings of the eighteenth dynasty, making altogether 342 years and 9 months: (including the 2
years and 2 months additional of Horus, in compliance with the version of the passage in the
Armenian text of the Chronicle of Eusebius.) This number, 342 years and 9 months, falling short
of the 348 years attributed to the eighteenth dynasty in Eusebius and Syncellus, M. Champollion
has suggested that Thoutmosis may have reigned the five years which constitute the difference,
before the expulsion of the shepherds, since, according to the record, he did reign, some years
before that event, over all the parts of Egypt not possessed by the shepherds. So far, so well: but
in such case, the year B.C. 1822, being the epoch of the expulsion of the shepherds, and not of
the commencement of the eighteenth dynasty, must surely correspond to the fifth year of the
reign of Thoutmosis, and not to the first, as M. Champollion makes it. We have hesitated to
venture this remark on a matter to which M. Champollion must have given much attention,
believing that mistake in us is much more probable than an accidental inadvertence in him; but
we have returned frequently to the consideration, without having been able to satisfy ourselves;
and the rectification of our mistake, if it is one, may prevent others falling into the same. [p190]

Proceedings of the Horticultural Society. ◊

June 19th.

A T this meeting a paper was read from the President, T. A. Knight, Esq.,
upon the culture of the mango and cherimoyer. Its object was to suggest
some improvements in the management of these and other trees cultivated
in stoves, deduced from an application of Dutrochet’s electrical theory of
vegetation to practice. It has now become generally known that this
observer is of opinion that the motion of the fluids in plants depends upon
two currents of electricity, setting with very unequal force between the
denser fluid of the tree and the lighter fluid of the soil in which the tree is
planted; the more powerful current setting from the latter to the former, and
so producing absorption, by conveying aqueous particles into the roots,
through the vegetable membrane of the epidermis. In applying this theory to

practical purposes, Mr. Knight recommends that the pot in which the
cherimoyer or mango is planted, should itself be surrounded by a medium
through which an equable and regular supply of fluid may be conveyed to
the roots, and that the naked surface of the pot should by no means be
exposed to the free action of the atmosphere. Without entering upon any
question of the accuracy of the French philosopher’s observations, it is quite
certain that such a mode of cultivation is that which is most congenial to
plants, and which is indispensable to those of a habit at all delicate. The
common practice of plunging pots into a tan-bed, or among sand, if in
glass-houses, or in the earth if in open borders, is a proof of the necessity
that gardeners have found, of securing as regular a temperature and degree
of humidity as is possible for the outside of their flower-pots; through the
pores in which, moisture is chiefly conveyed to the roots, which always
cling to the inside surface of the pot.
Specimens of roses produced by branches budded upon the Rosa indica,
were exhibited by Alexander Evelyn, Esq. We notice these not only on
account of their extraordinary beauty, but also for the sake of
recommending most strongly the adoption of the practice where delicate
roses are found difficult of cultivation per se. If we consider what happens
when the operation of budding, or grafting has succeeded, the reason of the
advantage derived from such an operation will be apparent. When a bud of
one variety is inserted under the bark of another variety, a union takes place
between the cellular substance of the two; the bud is then placed in the
same [p191] situation with regard to the stock, as the seed when sown is with
regard to the earth. It immediately derives its nutriment from the ascending
sap of the new tree, and begins to form its wood and branches, and to
secrete its proper juices in proportion to the supply of food it now receives.
If a plant from any cause produces roots with difficulty, its whole habit will
be delicate, and its flowers if formed, will, as in the case of that most lovely
of flowers, the double yellow rose, probably fall off without expanding,
from the want of an adequate supply of nutriment from its roots; but, as in
all trees, every bud is, when fully formed, in itself a perfect and distinct
individual, if such an individual be removed from its own root, and placed

where it will be supported by the healthy vigorous roots of another species
of variety, which happens in budding, it will no longer have to depend upon
a source, the supplies from which are imperfect, but on the contrary, like a
seed removed from barren fertile ground, it will flourish in a degree before
unknown. The contrary effect takes place when a vigorous plant is
transferred to one less vigorous. And hence, the whole effect of stocks upon
the scions, or buds inserted upon them.
There was also a great variety of fruit and flowers upon the table, and
seeds of several useful vegetables were distributed.

July 3rd.

Seven medals were awarded to different individuals for fruit sent by them
to the Society’s fête on the 23rd of June; and one to Capt. Drummond, for
his “successful exertions in bringing living plants of the mangosteen from
the East Indies.” A paper by the president was read upon an improvement in
the mode of constructing hotbeds, but we despair of explaining it
successfully without reference to figures. Among the display of fruits and
flowers, which were exceedingly numerous, we were particularly struck by
a collection of twenty-two varieties of strawberries from the Society’s
garden.
Upon this occasion, thirty-nine new members were either ballotted for, or
proposed, a striking proof of the estimation in which the Society is held by
the public.

July 17th.

Upon this occasion, an enormous pine-cone from the River Columbia
was exhibited. It measured 16 12 inches in length, and was stated to have
been procured by the Society’s collector, Mr. David Douglas. Its seeds were
represented to be as large as those of the stone-pine, and eatable. The tree is
of the family of Pinus strobus, [p192] and will be an invaluable acquisition to

our forests, if it should prove to succeed as well in this climate as in its
own. We have already given some account of this plant in the last number
of the old series of this Journal. The usual display was made of the finest
fruit and flowers of the season.

August 7th.

A complete coloured set of the costly Flora danica was placed upon the
table, having been presented by His Majesty the King of Denmark. An
improved apparatus for fumigating hothouses was exhibited by its inventor,
Mr. John Read: it consists of a brass cylinder, attached to the orifice of a
pair of bellows, and fitted up with a chimney and draft-hole closed by a
valve. The tobacco is put into the cylinder and ignited, and the blast from
the bellows expels the smoke. The contrivance is ingenious enough, but
while a hot-house fifty feet long, may be filled with smoke in ten minutes
by means of a flower-pot, with a hole in its bottom, and a common pair of
bellows, we cannot recommend any more expensive, and certainly less
efficient apparatus.
The table was covered with a profusion of fruits and flowers.

August 21st.

The meeting-room this day exhibited a gratifying proof of the excellence
of the productions of our English gardens. Of flowers, there were dahlias of
the richest colours, and the most varied hues; some produced by plants that
retain all their ancient stature, and others by dwarfs which seem to have lost
nearly every character of the dahlia but its beauty. Of fruits, there were
endless varieties of apricots, apples, pears, peaches, nectarines, grapes,
pine-apples, and melons; one of the latter, from the garden of John Fuller,
Esq., weighed thirteen pounds. The best apricot was the Moorpark; the best
apple, the Duchess of Oldenburg, than which no princess has a fairer
bloom, the best pear the Jargonelle, the best peach the Bourdine (forced),

the best pine apple the Black Jamaica. We mention these as a guide to our
readers, in their purchases of fruit-trees; for it is certain, that no greater
service can be rendered to the public, than to point out the means by which
they may avoid encumbering themselves with the polyonymous trash with
which every nursery abounds. [p193]

MISCELLANEOUS INTELLIGENCE.

I. M ECHANICAL S CIENCE . ◊

1. On the combined Action of a Current of Air and the Pressure of the
Atmosphere.

—The phenomena observed by M. Clement Désormes34, when a flat plate
is opposed to air or vapour passing into the atmosphere from an aperture in
a plane surface, have been rendered so easy of production by M. Hachette,
as to be at the command of any person in any situation. M. Hachette has
also accompanied the description of his instruments with elucidations,
experiments, and philosophical reasonings.
The first simplification by M. Hachette was to make the nozzle of a pair
of double chamber-bellows terminate in the middle of a flat plate; he found
that when the bellows were worked, effects were produced opposite the jet
of air of the kind described by M. Clement, disks of card and other
substances being drawn towards the aperture against the direction of the
current. At the same time that he described this experiment, he also
announced his having produced the same effects by using a stream of water
instead of a stream of air.

Fig. 1. Fig. 2.
The apparatus was still further simplified, so as to make the stream of air
from the mouth sufficient to produce the effect. A tin tube, A, Fig. 1, was
soldered to the middle of a round tin plate, in the centre of which was a
small orifice, E; three or four small projections of the tin, f f, were left at the
edges of the plate, to prevent the disks of paper, card, or metal, from
slipping off sideways. The figure is on a scale of one-half. Instead of the tin
plate, a piece [p194] of smooth cork may be used, and for the tin tube, a glass
tube, or one made by rolling up a piece of paper.
If the tube be held horizontally, or inclining a little upward, and a disk of
card or paper be placed loosely against the aperture in the plate, it will be
found that, on applying the mouth to the end of the tube, and blowing air
through, that the disk will not be driven away, but actually made to apply
closely to the surface of the plate; and if turned towards the ground it will
be found to remain opposite the hole, and not to fall until the current of air
is stopped. Even a plate of tin may in this way be suspended by a current of

air; which at first would be supposed to conjoin with gravity in forcing it to
the ground. When the disk is flexible and slightly elastic, a heavy sound,
and sometimes even a shrill tone, is produced by the vibrations of the plate.
In explanation of this experiment, M. Hachette says, “The air is pushed
from the mouth A of the tube, towards the orifice E of the plate; it strikes
the part of the disk opposed to this orifice, and the mean pressure on that
part is greater than the pressure of the atmosphere. The blown air then takes
place of that between the plate and the disk opposed to it; it moves in this
interval with a velocity decreasing from the edges of the aperture: the
elastic force of this air decreases at the same time, so that its mean pressure
between the plate and the inner face of the disk becomes less than the
atmospheric pressure; and as this last pressure is exerted on the whole
external face of the disk H, I, this disk, subject at the same time to the two
contrary pressures on its opposing faces, obeys the greater, and is pushed
towards the plate C D.”
“It is not necessary that the disk, C D, should be near the orifice E, of the
tube A E. Let Fig. 2 be an instrument composed of a hollow cylinder, C D F
G, and a flat border of the dimensions C″ F, or G D″. Let a tube, A E, be
fixed to the bottom of the cylinder, the orifice E having a diameter of about
three millimeters (0.12 of inch). If air be blown in at A, against the disk, H
I, in the neighbourhood of the flat border, the disk will be urged towards the
orifice E. This instrument is also delineated on a scale of one half. The disk,
with the attached weight, weighs about 12 grammes (184.87 grains), being
54 millimeters in diameter; the pressure of the atmosphere upon it equals 23
kilogrammes: from which it follows that, in this experiment, the pressure of
the air blown upon the inner surface of the disk, and the atmospheric
pressure exerted on the exterior of the same disk, only differs from each
other by about one two-thousandth part of the latter.”—Annales de Chimie,
xxxv. 34.

34 See the last volume of this Journal, p. 473.

2. Considerations relative to Capillary Action, by M. Poisson.

—M. Dutrochet, whilst explaining his views relative to the cause of vital
movement in plants and animals, stated that if an animal or vegetable
membrane were formed into a bag, having a tube of [p195] glass attached to
its aperture, and were then filled with a liquid substance, having a strong
affinity for another liquid, into which the bag was to be immersed, it would
not only have the power of absorbing the latter liquid into its pores, but
also, in certain cases, of forcing it up to the top, and even out of the glass
tube held in a vertical position. On this point, a difference of opinion with
regard to the force of capillarity took place: M. Ampère maintaining that
capillary action would raise the fluid to the top of the tube, but not cause its
expulsion; while M. Poisson maintained that, in certain cases, the latter
effect could be produced. The latter has since then published a note, which
we transcribe in part, from the Annales de Chimie, xxxv. 98.
Suppose that two different fluids, A, B, are contained
in a vessel, and separated the one from the other by a
vertical division; the heights being in an inverse ratio to
the densities, so that the points, a and b, in the two faces
of the division, and situated in the same horizontal plane,
shall support equal and opposite pressures: suppose also
that the division is pierced with one or more holes of
small diameter, or, in other words, that it is traversed by
several very narrow canals, as a, b, perpendicular to the
two faces, and which may be regarded at first as filled with air, or any other
fluid.
If the substance of the division exerts upon each of the two liquids an
action superior to the half of that which the liquid has upon itself, each
liquid will enter into the canal a, b, just as it would rise above its ordinary
level in a capillary tube of the same size and substance. It would also be
urged, by the excess of pressure which it would exert at the extremity of the
canal, against the elasticity of the included air. When the two fluids have
penetrated the interior of a, b, the air will be pushed on both sides in
different directions by forces each of which is equal to the primitive
pressure augmented by the corresponding capillary force, i. e. augmented
by forces proportional, according to the known theory of M. Laplace, to
double the action of the tube on the liquid, less the proper action of the

liquid itself. It will only be in the case when the capillary force shall be the
same on both sides, that the air, after being compressed to a certain degree,
will remain at rest: for whenever this force preponderates at one end of the
canal, the air will be driven out at the opposite end, and the liquid with the
strongest capillary attraction will entirely fill the canal.
Suppose this liquid to be A, then let us consider the forces which will act
on the portion a, b, of this liquid. At the extremity a, it will be submitted to
the attraction of the exterior fluid A: at the extremity b, it will be attracted
in the opposite direction by the liquid B. Now the two liquids being
different, their attractions will be unequal, and we will suppose that that of
B, on the matter [p196] of A, is greater than that of A for itself. As to the
action of the canal on the portion a, b, that will be equal, and exerted in
contrary directions at its two extremities; it will not, therefore, be either
adverse or favourable to the movement of the fluid in the canal: and the
same will be the case with respect to the pressures exerted at a and b, by the
external liquids, as long as they are equal: nevertheless, the action of the
canal, and the external pressures, will prevent the thread of fluid from being
broken, so that it will move without interruption in the direction in which it
is drawn by the greatest attraction, or from a to b. Hence will result an
elevation of the level of B, and, consequently, an increase of pressure at the
extremity b, of the passage, and this elevation will proceed until the
difference of pressure in a and b shall be equal to that of the attractions
exerted by the two fluids A and B, on the thread a b; this effect will be
produced the more rapidly as the division is pierced with a greater number
of passages similar to that which has been considered.
Now let us examine what would occur if the division were formed of two
others different in their nature, and exactly superposed; exerting no action
on one of the liquids, B for example, and one only acting on the other
liquid. The liquid B will then retain its original position undisturbed; in
consequence of the action it exerts upon itself it cannot penetrate the canal a
b, just as mercury cannot escape by a capillary aperture made in a
barometer-tube. It will be the same with A, when that face of the division
which exerts no action upon the liquid is turned towards it; so that how
numerous soever the apertures, the two liquids would, under such
circumstances, remain separate and preserve their original level. But if the

division be turned so that the face which acts upon A shall be in contact
with that liquid, it will penetrate the canal a b by means of capillary
attraction; and the velocity which the liquid urged by this force may
acquire, may make it pass that point in the canal where the division changes
its nature, and even make it reach the extremity in the liquid B, so that it is
possible that the liquid A should entirely fill the canal a b, as in the case
which has already been examined. Then if we always suppose the attraction
of B for A to be superior to that which A has for itself, the thread a b will
flow into B until the level of the latter is so far altered that the excess of
pressure at b can balance the difference of attractions exerted by the two
liquids at a and b.
M. Poisson then observes that, without pretending to assign a cause,
exclusive of all others, for the phenomena of absorption by vegetable and
animal membranes observed by M. Dutrochet, his object is to show that
effects which have at least a great resemblance to these important
phenomena, may be produced by capillary action conjoined with the
difference of affinity existing between heterogeneous substances without
the assistance of electricity, either moving or quiescent. It appears that M.
Dutrochet afterwards [p197] found mineral substances, as a piece of slate,
might be substituted for the organized tissues; this being the case, the
opinion which refers such effects to a general cause, as capillary attraction,
acquires more probability.

3. Novel Use of the Plough.

—Mr. Bruckmann states that he has long thought the plough might be used
in levelling roads and clearing the foundations for fortifications. In 1824 he
had an opportunity of applying it in the construction of a canal required to
furnish a motive force for the service of the rock-salt works of
Friedrichshall. The bed was to have a section of 700 square feet, and it had
been calculated that the excavations would require 200 men for two years,
whereas the king of Wurtemburg wished it to be done in one year from the
spring of 1824.
Three ploughs were employed; the first had two handles, a coulter, and a
share, the latter being in the form of a wedge. This plough was preferred in

the beds and gravelly grounds; and it was found advantageous to give it an
oscillatory movement by the handles during its progress. Drawn by eight
horses, it could turn up 25,000 cubic feet of an argillaceous soil, in three
hours; with ten horses it turned up 19,800 cubic feet of a gravelly soil, in
the same time. This plough was tried in 1815, against fifteen others of the
ordinary kind, in the construction of a watercourse for a mill; all the fifteen
were quickly broken by the work.
The second plough had two handles and a coulter, but the share had only
one cutting edge, which was rounded and with an ear. It was made five
times as strong as an ordinary plough, and succeeded well in compact and
argillaceous soils, where, with eight horses and four men, it moved 48,000
cubic feet of earth in three hours. In case of fracture ten minutes sufficed to
change the coulter and share, and, during the work, 2,300,000 cubic feet of
earth were loosened by it.
The third plough was smaller and lighter, it had two handles, a coulter, an
ear, and a share, the latter lance-shaped. It was used for excavating the sides
of the canal, on which the horses attached to the first plough found it
difficult to walk because of the inclination. It was worked by ten or twelve
men.
To establish an accurate comparison between the work of these ploughs
and that done by the pickaxe and spade, a piece of ground was wrought
solely in the latter manner by six strong working men. The result of a long
trial was the breaking of 150 cubic feet of ground by each man in nine
hours. Comparing this result with the work of the ploughs, the following are
the results:—The first plough did the work of 477 men, the second of 960
men, and the third that of 50 or 60 men. The canal was finished on April
30th, 1825, the ploughs having saved 32,000 days, according to the work-
day of a labourer.—Bull. Univ. D. vii. 343. [p198]

4. Discovery of Rocks under the Surface of the Sea.

—The fishers of the Mediterranean use an apparatus for the discovery of
rocks beneath the surface in those places where they wish to cast their nets,
which supplies, in a great measure, the insufficiencies of the ordinary
means of taking soundings. The method consists in carrying a long and thin

cord over the bottom to be examined, and which, when it meets with an
obstacle, is stopped by it and becomes folded in the place where it occurs. It
will easily be understood, that when a cord has been carried over a certain
space without meeting with any resistance, that proof is obtained of the
non-existence of rocks or other obstacles, at a depth less than that to which
the cord has been sunk; and as the examination can easily be carried on to
100 feet below the surface, it may be said that, wherever such an apparatus
has passed unimpeded, the navigation is free. If, on the contrary, some
isolated rocks are found during the examination, the place where the cord
becomes doubled points out the locality, which may then be determined
more accurately by other trials, and the summit and neighbourhood of the
submersed rocks be accurately examined by means of soundings.—Annales
Marit.; Bull. Univ. F. viii. 44.

5. Paper to resist Humidity.

—This process, which is due to M. Engle, consists in plunging unsized
paper once or twice into clear solution of mastic in oil of turpentine, and
drying it by a gentle heat. The paper, without becoming transparent, has all
the properties of writing-paper, and may be used for the same purposes. It is
especially recommended for passports, workmen’s books, legal papers, &c.
When preserved for years it is free from injury, either by humidity, mice, or
insects. It is further added, that a solution of caoutchouc will produce even a
still better effect.—Kunst und Gewerbe-blatte.

6. Professor Amici’s Microscopes.

—This distinguished personage has lately exhibited to the savans of this
country two microscopes of his own workmanship,—an achromatic
refractor, and a reflector of his own particular invention. The object-glass of
his refractor is of a very complicated construction, and is composed of three
double-object glasses combined together in the space of about an inch. The
flint-glass from which his concaves are formed is of the manufacture of
Frauenhofer; his convexes are of Dutch plate, crown-glass, and French

plate, separately. Each object-glass detached has but a small aperture, and is
of long focus; but when the three are combined together, the angle of
aperture is very considerable, and the focus short. By this ingenious
arrangement the trouble and difficulty of manipulating deep single-object-
glasses of large aperture is avoided; but advantages gained one way, in
practical optics, are generally lost in another, and the twelve surfaces of the
objective produce a kind of softness and muddiness in [p199] the image
strongly contrasted by the effect of a good single triple-glass of equivalent
power. When, however, only two of the object-glasses are combined, the
effect is very fine. Between the object-glass and eye-glasses is placed one
of those prisms originally invented by Sir I. Newton to act as an eye-piece
of his telescope, and of which a description may be seen in his
correspondence at the end of Dr. Gregory’s Optics. The utility of the
introduction of this device appears very questionable in an instrument
already so complicated. The diversion of the rays into a course at a right
angle to their original progress (merely to give an horizontal instead of a
vertical position to the body) is surely no warrant for the employment of
two extra refracting surfaces and one reflexion, which cannot fail to have a
pernicious influence on the formation of the image. An horizontal position
of the body is attained with the utmost facility by a proper construction of
the mounting, &c. Setting aside the dulness of the image produced by the
numerous refractions, the performance of the instrument on test-objects was
highly respectable and satisfactory.
The reflector is a modification of the original construction recommended
by the Professor, who seems to have profited by the schooling he received
from Dr. Goring, and now sails much closer to the wind than he did. His
objective metal is now two inches focus, with an aperture of 1 12 inch; but
half an inch is cut off for the purpose of preventing the bad effect of the
marginal rays, so that only 1 inch of the central portion of the metal is
employed;—the diameter of the diagonal mirror is also reduced to its proper
standard, by which means the blot in the centre of the visual pencil is
rendered as small as possible. It may be asserted of this instrument, that it
does as much as can possibly be expected from an objective part of 2 inches
focus, showing many test-objects faintly, and with much effort; but it is
totally unable to compete with deeper ones equally perfect and of the same

angular opening. The Professor has, in some of his instruments, reduced the
focus of the elliptic metal to 1 12 inch, and will, no doubt, gradually slide into
the adoption of that radical reform in his instrument, so happily carried into
effect in this country by Dr. Goring, in conjunction with Mr. Cuthbert,—at
3 2
least if the figuration of elliptic metals of 10 inch focus with 10 inch of
aperture shall not surpass his powers of execution. During the Professor’s
stay in this country there was a grand field-day at his hotel, at which both
his microscopes were tried against the Goringian modification of the
reflector, the superior weight of metal of which completely beat every thing
opposed to it. For the honour of the Professor it must be stated, that he
admitted this defeat with great candour and good sense, and even had some
difficulty in believing in the identity of some of the objects used, so
differently was the ordinary apparent structure developed by the English
improvements on his instrument. It may with safety be averred that no
refractor, at least, will ever be [p200] made to surpass Dr. Goring’s improved
Amician Engiscope; and it seems equally certain that no other reflector will
ever be invented capable of the same facilities of application to the
examination of both opaque and transparent objects. If Professor Amici has
been beaten, it has been done with his own weapons,—the copy has
surpassed the original,—the child, by virtue of foreign nursing and tuition,
has exceeded the stature and strength of the father.

II. C HEMICAL S CIENCE . ◊

1. On the Specific Heat of Gases, by MM. de la Rive and Marcet.

—The principle on which these philosophers proceeded in their researches,
was, to expose equal volumes of different gases to an equal source of heat
during equal times, and to judge, by the augmentation of elastic force in
each gas, the temperature which it had acquired. The apparatus was a kind
of manometer, and consisted of a glass balloon to retain the gas, and a bent
tube attached to it, which, descending into a vessel of mercury, served to
show, by the column of metal within it, what was the elasticity of the gas.
This method was adopted, because, i. The gas was not altered in volume by
the change of temperature, its elasticity only changing: ii. The temperature
was indicated by the gas itself, and not by a thermometer: iii. Water was
easily separated previously from the gases, and excluded from the
apparatus: iv. All the gases were placed in exactly the same circumstances,
so as to render it unnecessary to refer to any calculation for the purpose of
comparison.
Two methods of applying heat were resorted to: in one the balloon,
containing the gas at a certain temperature, was placed in water at a higher
but constant degree, for a certain time (generally 4′), and the elevation of
temperature noticed: in the other, the balloon with the gas was inclosed in a
larger copper balloon, blackened inside, and the space between the two
exhausted as much as possible of air; the apparatus being then immersed in
warm water, the heat gained access slowly to the gas, and the time of each
experiment was increased, at the same time that certain sources of error
were avoided.
The gases experimented with were, atmospheric air, oxygen, azote,
hydrogen, carbonic acid, olefiant gas, oxide of carbon, nitrous oxide,
nitrous gas, sulphuretted hydrogen, ammonia, sulphurous acid, muriatic
acid, and cyanogen. Great care was taken in their preparation. The result of
the experiment was very unexpected; for, during the five minutes allotted
for each, all had acquired the same temperature,—a circumstance which

proves that they all have the same specific heat. The equal volumes of gas
at the pressure of 65 centimeters (15.59 inches) and the temperature of
20° C., being exposed to a source of heat at 30° C., acquired a mean
temperature of 6.32 degrees in five minutes, the extreme difference, in any
of the experiments, not being more than 0.04 of a [p201] degree. One gas
only forms an exception to the above statement, namely, hydrogen, which
was always heated more than the others, namely, to 6.6 degrees in the five
minutes. This effect is considered as due not to any difference in specific
heat, but to a difference in conducting power.
Experiments were then made with dilated gases, to ascertain whether
dilatation caused any change in capacity, and it was found to diminish
slowly but regularly with the diminution of pressure. These results, with a
third which is also interesting, have been thus generally expressed by the
authors at the end of their memoir.
i. All gases in equal volumes, and at the same pressure, have the same
specific heat.
ii. Other circumstances being the same, the specific heat of gases
diminishes with diminution of pressure, and equally for all the gases: the
progression converges slightly and in a ratio much less than that of the
pressures.
iii. Each gas has a different conducting power, i.e., all the gases have not
the some power of communicating or receiving heat.—Ann. de Chimie,
xxxv. 5.

2. On the Incandescence and Light of Lime.

—The experiments made by Lieutenant Drummond upon the light of lime
and other earths when highly ignited, with the highly interesting application
which he has made of that emitted from lime, to the purpose of geodesical
surveys, has induced M. Pleischel to repeat and vary the results. He states
that the utmost light is given by lime; the earth being pulverised and
exposed on burning charcoal to the heat excited by a jet of oxygen falling
upon it. He endeavours to account for the effect, by supposing a kind of
pulverulent atmosphere disengaged from the lime at the high temperature
used, and considers that the substances which are competent to emit

molecules only in the gaseous state, cannot produce this intense light.—
Zeitschrift für Physik, &c.

3. Evolution of Heat during the Compression of Water. May 14, 1827.

—M. Arago announced to the Academy of Sciences, that M. Despretz had
ascertained experimentally, that the compression of water by a force equal
to 20 atmospheres, caused the disengagement of one sixty-sixth part of a
degree of heat.

4. On Electrical Excitation.

—M. Walcker affirms positively from experiments made with great care,
that three bodies of different exciting power are necessary, in every case of
excitation of electricity by contact, and that all the phenomena of this kind
are subject to this condition. If, for instance, two portions of the same metal
being put in contact, electricity is produced, it is because there are three
different states of temperature brought into play, one being the result of the
other two, and a mean between them. One fact which more than any other
sanctioned this idea, was, that the electric [p202] currents were the more
apparent as this third state of temperature was made more sensible.—Bull.
Univ., A. vii. 374.

5. Magnetic Repulsion.

—A very remarkable result has been obtained by M. Becquerel, from the
use of an extremely delicate magnetic arrangement, which he has for the
present called a sideroscope. Its use is exactly the same in principle as that
of the magnetic needle, indicating iron, for instance, by the attraction
manifested; but it is so delicate that it will show it in the most minute
quantity possible, as, for instance, in gold, silver, or copper money,
innumerable minerals, &c. This instrument shows no magnetic power or
attraction in gold, silver, copper, palladium, tin, lead, zinc, or brass, when

chemically pure, and a great many vegetable and mineral substances have
no action on it: but the most curious result is, that very pure bismuth and
even that of commerce has a repulsive power, which, if it be found
ultimately to be independent of any magnetic polarity, is the first fact of the
kind that has been made known. Antimony also presents the same
phenomenon.

6. Diminished Solubility of Substances by Heat.

—Mr. Graham has added one to the few facts of this kind with which we
were acquainted, and has accompanied its description with some very
interesting considerations, which may be found at length in the
Philosophical Magazine, N. S., ii. 20. The salt experimented with by Mr.
Graham is the phosphate of magnesia; which may be prepared by mixing a
solution of 21 parts of phosphate of soda with one of 15.375 parts of
sulphate of magnesia: within 24 hours the phosphate of magnesia
precipitates in acicular crystals; they should be agitated with repeated
portions of water, then thrown upon a filter with more water, and left to dry.
Solutions were obtained by occasionally agitating this salt with water in
the proportion of 2 ounces to a pint of the fluid, for four days; being then
decanted and filtered, they had a sweetish taste. A quantity of this fluid
being heated in a water-bath, became turbid before the temperature had
attained 120° F.; at 212° a cloudy precipitate slowly subsided, and the
supernatant fluid became nearly transparent. The precipitate was found to
be anhydrous phosphate of magnesia; and, by further experiment, the
difference in solubility was found to be such, that water at 45°, dissolving
1
744
th part its weight of the anhydrous salt, water at 212° only dissolved
1
1151
th part. When in the state of crystals, or as hydrate, the proportions of
1 1
salt were 322 and 498 to 1 of water.
Mere continuance of the heat had no effect in increasing the precipitate
either of this salt, or from aqueous solution of lime, provided no part of the
solution was at any time converted into vapour; but if the solution only
occupied a small part of the vessel, and ebullition came on, then, although

all the water might be returned to the solution, yet the precipitation went on,
and might be [p203] increased ad libitum, particularly in the case of lime
water. The cause of the precipitate appears to be the same in all these cases.
The moment a drop of the solution is converted into vapour, it deposits the
quantity of lime or salt which it held in solution; and in the case of bodies
which dissolve so sparingly and with so much difficulty, although the water
be returned again to the solution, it is incapable of re-dissolving what it has
deposited. We know that it would be a hopeless task to form a saturated
solution of lime by agitating with the water no more than the few grains
which it is capable of dissolving; and in the case of ebullition, when the
lime is once deposited, there should be the same difficulty in taking it up.
Mr. Graham states that he has observed this effect not only in lime-water
and in solution of phosphate of magnesia, but to a certain extent in all
bodies of difficult solubility, in the sulphate of lime, for instance, even
when greatly diluted; and he believes that the deposite from slight boiling
observed in many mineral waters, and generally attributed to the dissipation
of carbonic acid gas, depends, in some instances, upon this cause. However
weak the solution may be, it is evident that a portion of the salt may be
deposited in this way.

7. On the Composition of Cyanic Acid.

—M. Wohler some time since announced the production of cyanic acid, and
cyanates, corresponding in composition to the substance presumed to exist
in the fulminating compounds of silver, mercury, &c., the nature of which
was made out by MM. Liebig and Gay Lussac. M. Liebig, upon repeating
M. Wohler’s experiments upon his cyanate of silver, obtained only 71.012
per cent. of oxide of silver, instead of 77.23, which was the quantity present
according to M. Wohler’s analysis, and concluded that the acid was the
cyanous, and not the cyanic. The latter philosopher was consequently
induced to repeat his experiments: one of his methods of decomposing the
cyanate of silver was by muriatic acid gas: at first liquid cyanic acid forms,
which is very soon transformed into a white crystalline mass; but, on
continuing the operation, and applying a higher heat, a large quantity of
muriate of ammonia and cyanic acid is evolved. This process indicated 77.5

per cent. of oxide of silver in the salt. Another process consisted in
dissolving the cyanate in nitric acid, and precipitating the silver by muriatic
acid, the result was 77.05 of oxide per cent. A third analysis, made by
reducing the silver of the salt, gave a result of 77.35 per cent. oxide. The
mean of these is 77.3, and the theoretical number obtained by calculation is
77.23, so that the acid appears to be truly the cyanic; and the curious fact of
its being the same in composition with that in the fulminating compounds
of silver and mercury, but very unlike in properties, still remains
undisturbed.—Bull. Univ., A. viii. 53.

8. Iodous Acid.

—According to M. Wohler, the iodous acid of [p204] M. Sementini35 is
nothing more than a mixture of chloride of iodine and iodine. When
saturated with carbonate of soda, the iodine in solution is precipitated, and
on evaporating the solution to dryness, and heating it strongly, the residue
fuses, and by proper tests is found to be a mixture of chloride and iodide of
sodium.
These statements apply only to the iodous acid: as to the oxide of iodine,
no source of chlorine exists in the process last described by M. Sementini.

35 See the last volume of this Journal, p. 477.

9. On Manganesic Acid, by M. Unverdorben.

—When manganesate of potash is distilled with a little anhydrous sulphuric
acid, manganesic acid is evolved in the form of a red transparent gas, which
dissolves in water, forming a red solution. The gas frequently decomposes
spontaneously in the retort, with explosion, producing oxide of manganese
and oxygen.
Manganesate of potash was analysed by distilling it with excess of
sulphuric acid, collecting the oxygen disengaged, and estimating the

proportion of protoxide of manganese and salts of potash remaining in the
retort. According to these experiments the acid consists of
Manganese 58.74
Oxygen 41.26
100.00

And the
Or being
manganesate
calcined
of potash of
Potash 25.63 32.75
Manganese acid 52.44 67.25
Water 21.93 100.00
100.00

Ann. des Mines, 1827, p. 145.

10. Heavy Muriatic Ether, and Hydrocarburet of Chlorine or Chloric Ether.

—Some comparative experiments have been made on these two substances
by M. Vogel. He prepared the former of them by passing chlorine gas into
alcohol. The muriatic acid was then separated by distilling the fluid from
off chalk, in which operation the muriatic ether and alcohol passed over
together, and these were divided by the addition of water, which dissolved
the latter, and left the former. The chloric ether was made as usual from
chlorine and olefiant gases. The results that were obtained by acting on
these substances by a high temperature, potash, phosphorus, &c., induced
M. Vogel to consider them as identical in composition, notwithstanding
some differences in their physical properties; the specific gravity of the
muriatic ether was 1.134, that of the chloric ether 1.214, and the odour of
the latter is more aromatic, and the taste more sweet than of the former.
Whilst passing the chlorine into the alcohol, M. Vogel observed [p205] that
if the sun shone upon the substances when the action was nearly complete,
each bubble of chlorine as it entered the alcohol produced a bright purple
flame, a dense white vapour, and caused violent concussions in the liquid;

another curious instance, in addition to the many that are known, of the
power of solar light over chemical action.—Journ. de Pharm. 1826, p. 627.

11. Test for the Presence of Nitric Acid.

—The following method is one devised by Dr. Liebig, for the detection of
this substance, which it will effect, he says, when there is not more than a
four-hundredth part of the acid present. The liquid to be examined must be
mixed with sufficient sulphuric solution of indigo to acquire a distinct blue
colour, a few drops of sulphuric acid added, and the whole boiled. If the
liquid contains a nitrate, it will be bleached, or, if the quantity is very small,
rendered yellow. By adding a little muriate of soda to the liquid before
applying heat, a five-hundredth of nitric acid may easily be discovered.—
Ann. de Chimie, xxxv. 80.

12. Peculiar Formation of Nitre.

—The leaves and stems of beet root contain oxalate and malate of potash.
Some leaves were tied together and hung up in a warm and slightly-humid
place, where there was but little light, to dry. Being examined at the end of
several months, they were found penetrated with, and covered by, an
immense number of minute crystals of nitre. The oxalic and malic acids had
been replaced by nitric acid; but whether from animalized matter naturally
in the leaves of the plant, or from the action of the air, or in what manner, is
not known.—M. H ENRI B RACONNOT , Ann. de Chimie, xxxv. 260.

13. Experiments on Fluoric Acid and Fluates, by M. Kuhlman.

—These experiments were made with dry sulphuric acid and fluor spar,
with the intention of proving that fluor spar is truly a compound of fluorine
and calcium, and not of fluoric acid and oxide of calcium. A quantity of
anhydrous sulphuric acid was prepared with great care, and collected in a
glass tube; the latter was then connected with a platina tube charged with

fluor spar, which had previously been calcined in a platina crucible, and a
glass tube was connected with the other end of the platina tube for the
purpose of conducting and facilitating the collection of the gas evolved over
mercury. The fluor spar was heated to redness, and then the temperature of
the sulphuric acid raised so as to cause a stream of it in vapour to pass over
the fluor spar; but there was not the slightest reaction, the sulphuric acid
recondensed in part in the farthest tube, and no trace of fluoric acid was
produced. Dry sulphuric acid was then put, in the liquid state, in contact
with dry fluor spar, but there was no decomposition, and no portion of the
spar was converted [p206] into sulphate of lime. The first experiment was
then repeated, with the difference of using hydrated sulphuric acid of
specific gravity 1.842, and there was instantly much fluoric acid produced,
which acted upon the glass.
As Berzelius found 100 parts of fluor spar, when acted upon by sulphuric
acid, to yield 175 parts of sulphate of lime, equal to 73.553 parts of lime, or
52.819 of calcium, it follows that 100 parts of fluoride of calcium should
contain 47.181 of fluorine and 52.819 of calcium. By the assistance of this
result, and further experiments, M. Kuhlman proceeded to ascertain the
composition of hydro-fluoric acid. Dry muriatic acid gas was passed over
calcined fluor spar heated to redness in a tube of platina; the fluoride of
calcium was decomposed, free hydro-fluoric acid was evolved, and chloride
of lime remained in the tube. The hydro-fluoric acid acted upon the glass
tubes, but being received in water was entirely dissolved, with the exception
of the silica it had separated from the glass: no trace of hydrogen appeared.
One hundred parts of fluoride of calcium thus treated became 143.417 parts
of chloride of calcium, the 52.819 parts of calcium having united to 90.598
parts of chlorine. But this latter quantity must have liberated 2.511 parts of
hydrogen, which must, therefore, have combined with the 47.181 parts of
fluorine in the spar, to form 49.692 parts of hydro-fluoric acid. This latter
body, therefore, consists of 94.941 fluorine, and 5.059 of hydrogen per cent.
A small quantity of chlorine was set at liberty during the experiment, the
author thinks, from a little manganese in the fluor spar.
M. Kuhlman found that all the chlorides, when subjected to the action of
anhydrous sulphuric acid in vapour, resisted decomposition, except the
chloride of sodium, which gave a small quantity of sulphate of soda, and a

double salt of soda and platina, crystallizing in fine needles of a yellow
colour. No doubt is entertained that, in the latter case, the common salt and
sulphuric acid were not perfectly dry.—Bull. Univ.

14. Crystallization of Phosphorous.

—By the fusion and careful refrigeration of a large quantity of phosphorus,
M. Frantween has obtained very fine crystals of an octoedral form, and as
large in size as a cherry-stone.

15. Solutions of Phosphorus in Oils.

—The solutions of phosphorus in fixed oils are so luminous as often to be
resorted to for the exhibition of this peculiar property of phosphorus; but M.
Walcker has remarked, that the power which they ordinarily possess is
instantaneously destroyed by the addition of small quantities only of certain
other substances, as the essential oils. The rectified oils of turpentine and
amber, the oils of rosemary, bergamotte, lemon, camomile, angelica root,
juniper berries, and parsley seed, [p207] the oil obtained by the distillation of
the nutmeg, all produce this effect when their quantity is not more than one-
fiftieth part of the luminous oily solution of phosphorus. The same effect is
produced by adding about a fifth of the oils of anniseed, cajeput, lavender,
rue, sassafras, fern, cascarilla, mint, orange flowers, fennel, valerian, cherry
laurel, or bitter almonds, or balsam of copaiba; but the oil of cinnamon,
rectified petroleum, balsam of Peru, and camphor, have no such effect.—
Annal. der Phys. 1826, p. 125.

16. On the Inflammation of Powder when struck by Brass, &c.

—Iron has been excluded from powder-works as subject to cause sparks by
a blow, and brass and copper have been recommended in its place. M. le
Col. Aubert has remarked, that brass on brass can inflame powder, and has
made experiments on the subject before a committee, the result of which is

as follows:—Inflammation of the powder takes place when the blow is
given by iron against iron; iron against brass; brass against brass; iron
against marble; lead against lead, or against wood, when the blow is
produced by a leaden ball shot from a fire-arm. As yet the powder has not
been inflamed by the blow of an iron hammer against lead or wood.—Bull.
de la Soc. d’Encouragement; Bull. Univ.

17. Cementation of Iron by Cast Iron.

—Pure iron, when surrounded by, and in contact with, cast iron turnings,
and heated, is carbonised very rapidly, so as to harden, to temper, and, in
fact, to exhibit all the properties of steel. M. Gautier finds this a very
advantageous process in numerous cases, especially where the articles to be
case-hardened, or converted into steel, are small, as iron wire, or wire
gauze. The temperature required is not so high as that necessary in the
ordinary process of cementation, and the pieces to be carbonised are not
injured in form. The kind of cast iron used should be the gray metal, and the
more minutely it is divided the more rapid and complete is the operation.
By covering the mass of cast metal, in which the iron to be carbonised is
enveloped, with sand, oxidation, from contact of the air, is prevented, and
the cast metal may be used many times. Plumbago experimented with in the
same manner does not produce the effect.—Jour. de Pharmacie, 1827, p.
18.

18. On the Preparation of Ferro-prussiate of Potash, by M. Gautier.

—Numerous investigations induced M. Gautier to conclude, that, i. When
animal matter is calcined alone it yields but little cyanogen. ii. That when
mixed with potash it gives more, but the cyanuret is not ferruretted. iii. That
ammonia is then produced in large quantity. iv. That the substitution of nitre
for potash, and the addition of iron or scales of iron, augmented the
production of cyanogen, and gave a ferro-prussiate. The following is the
process of manufacture to which M. Gautier has ultimately arrived, [p208]

and which he has practised for some years. The proportions of the materials
are—
Blood, considered
as in the dry state, 3 parts
Nitre 1 part
Iron scales 1
50
of the blood
employed.

The blood is first to be coagulated in a large copper cauldron, and the
serum being separated by means of a press, the coagulum is to be returned
to the cauldron with the nitre and iron. The quantity of water contained in
the blood is sufficient to liquify the salt, so as to allow of an uniform
mixture being effected. The mixture is then removed, and exposed in an
airy situation to dry, the putrefaction of the blood being prevented by the
nitre. When the desiccation is complete, the mixture is charged into cast
iron cylinders, which are fixed in a reverberatory furnace, and in all things
resemble those used in the preparation of animal charcoal. These are to be
raised to a brown red heat, until no more vapour is disengaged, and then left
until nearly cold, after which the contents are to be withdrawn and put into
a wooden vat, with twelve or fifteen times their weight of water, for an
hour. The fluid is then to be filtered through a cloth, and evaporated until of
32° of Beaué (specific gravity 1.284.) Being then left to cool, a large
quantity of well-crystallized bi-carbonate of potash is obtained. M. Gautier
says he has not, as yet, been able to explain how it is that this bi-carbonate
has been formed at so high a temperature; a portion also appears to be
decomposed during the evaporation of the solution, which, at first but
slightly alkaline, becomes sensibly so by a prolonged evaporation.
As the same product is not obtained when potash is used in place of nitre,
it is probable that the elements of the nitric acid perform a particular part in
the operation.
The solution which has given the crystals of carbonate of potash contains
a little carbonate of potash, and much ferro-prussiate of potash. It is to be
concentrated to 34° (specific gravity 1.306), and placed in wooden vessels
lined with lead. In the course of some days a greenish crystalline mass is

obtained, which being redissolved in a fresh quantity of pure water, and
evaporated to 32° or 33° (specific gravity 1.295), is to be recrystallized.
Sometimes, when using potash, M. Gautier has mixed nitre with it, and
has always obtained a richer product than when potash alone had been
employed.—Jour. de Phar. 1827, p. 11.

19. Sulphocyanide of Potassium in Saliva.

—MM. Tiedemann and Gmelin have observed the existence of this peculiar
compound in saliva, in two cases; the one when the fluid was secreted
during smoking, and the other when no such stimulus was applied.—Ann.
de Chimie, xxxv. 266.

20. Decomposition of Sulphate of Copper by Tartaric Acid.

—M. [p209] Planche has observed, that when sulphate of copper is dissolved
in wine vinegar, for the purpose of preparing a corrosive liquid to be
applied to corns on the feet, that the tartaric acid present in the vinegar
displaces the sulphuric acid from a part of the salt, and an insoluble acid
tartrate of copper is produced.

21. Separation of Arsenic from Nickel or Cobalt.

—The following process by M. Woehler seems among the best of those
intended for freeing nickel or cobalt from arsenic in the dry way. It is
founded upon the circumstances that many alloys, when heated with
sulphuret of potash, become changed into a mixture of sulphurets, and that
sulphuret of arsenic is very soluble in sulphuret of potash. One part of
kupfernickle, fused and reduced to fine powder, is to be mixed with 3 parts
of carbonate of potash, and 3 parts of sulphur, in a covered Hessian
crucible. The heat is to be gradually raised to redness, and until the mass is
just entering into fusion, and by no means so highly as to fuse the sulphuret
of nickel which is formed. When cold, water is to be added, which will

dissolve the sulphuret of potash, and leave a yellow crystalline powder,
which is sulphuret of nickel, retaining, perhaps, a little copper or cobalt, but
no arsenic, if the operation has been well performed. When, however, the
object is to have the nickel perfectly pure, it should be fused a second time
with sulphur and potash.
The method of freeing cobalt from arsenic, is the same as for nickel; but
it is then necessary to perform the operation a second time. The cobalt (that
of Tunaberg) has never been perfectly freed from arsenic by one operation,
but has never retained any after the second.—Archiv für Bergbau, 1826, p.
186.

22. Compounds of Gold.

—According to late experiments of Dr. Thomson, peroxide of gold consists
of
1 atom gold 25
3 " oxygen 3
28

and is consequently a teroxide. Muriate of gold consists of
2 atoms muriatic acid 9.25
1 " per oxide of gold 28.
5 " water 5.625
42.875

Edin. Journal, p. 182.

23. Chemical Researches relative to certain Ancient Substances.

—M. Vauquelin has analyzed, i. A poignard blade formed of copper only; ii.
A mirror, which was found to consist of 85 parts of copper, 14 of tin, and 1
of iron per cent.; iii. A blue colour found in a tomb: [p210] it was composed
of silica 70 parts; lime 9; oxide of copper 15; oxide of iron 1; soda mixed

with potash 4. A blue identical with this, both in colour and composition,
was found in the bottom of a furnace in which copper had been fused at
Romilly.
M. D’Arcet has examined a bone from the fore part of an ox, which had
been placed as an offering to the divinity in an Egyptian tomb, and found
that it contained as much gelatine as recent bone, although rather less is
obtained by muriatic acid, (20 per cent. instead of 27) because of a
deterioration of the bone. When burnt, it gave an animal black as deep in
colour as that from recent bone.
M. Le Baillif has examined some grains of corn, which were so well
preserved, that when put into boiling water iodine produced the blue colour
dependent upon starch. He also made some experiments on a gummy
substance, and on two cords from a musical instrument; the latter were of
animal substance.
M. Raspail examined some grain which was supposed to be wheat, but
found it to be torrified barley; it was covered with a substance
communicated probably by the oil and incense with which the grains were
bathed when consecrated. Similar grains were obtained by roasting
common barley.
The account of most of these researches is given in the Catalogue
raisonné et historique des Antiquités découvertes en Egypte, by M.
Passalacqua.—Bull. Univ. A. vii. 264.

24. On the Bitter Substance produced by the action of Nitric Acid on Indigo,
Silk, and Aloes, by M. Just Liebeg.

—The process by which M. Liebeg obtains a pure and uniform substance
from the action of nitric acid on indigo, is as follows:—A portion of the best
indigo is to be broken into small fragments, and moderately heated with
eight or ten times its weight of nitric acid of moderate strength. It will
dissolve, evolving an abundance of nitrous vapours and swelling up in the
vessel. After the scum has fallen, the liquid is to be boiled, and nitric acid
added, whilst any disengagement of red vapours is occasioned by it. When
the liquid has become cold, a large quantity of semi-transparent yellow
crystals will be formed, and if the operation has been well conducted, no

artificial tannin or resin will be obtained. The crystals are to be washed with
cold water, and then boiled in water sufficient to dissolve them. If any oily
drops of tannin form on the surface of the solution, they must be carefully
removed by touching them with filtering paper. Then filtering the fluid, and
allowing it to cool, yellow brilliant crystalline plates will be obtained,
which will not lose their lustre by washing.
To obtain the substance perfectly pure, the crystals must be re-dissolved
in boiling water, and neutralized by carbonate of potash. Upon cooling, a
salt of potash will crystallize, which should be purified by repeated
crystallizations.
On mixing the first mother liquor with water, a considerable brown
precipitate will be obtained, which being dissolved in boiling [p211] water,
and neutralized by carbonate of potash, will furnish a large quantity of the
potash salt. All the potash salt obtained in these operations is to be re-
dissolved in boiling water, and nitric, muriatic, or sulphuric acid added; as
the solution cools, the peculiar substance will be observed to form very
brilliant plates of a clear yellow colour, generally in equilateral triangular
forms.
Sometimes crystals are not formed after the action of the nitric acid on
the indigo, in which case the liquor must be evaporated, and water added,
when the substance will precipitate, and must be purified as already
described. Four parts of indigo yield one of the pure substance.
When the substance is heated, it fuses, and is volatilized without
decomposition; when subjected to a sudden strong heat, it inflames without
explosion, its vapours burning with a yellow flame, and a carbonaceous
residue remaining. It is but little soluble in cold water, but much more in
boiling water; the solution has a bright yellow colour, reddens litmus, has
an extremely bitter taste, and acts like a strong acid on metallic oxides,
dissolving them, and forming peculiar crystallizable salts.—Ether and
alcohol dissolve the substance readily.
When fused in chlorine or with iodine, it is not decomposed, nor does
solution of chlorine affect it. Cold sulphuric acid has no action on it; when
hot, it dissolves it, but water separates the substance without alteration.
Boiling muriatic acid does not affect it, and nitro-muriatic acid only with
great difficulty.

These results show that no nitric acid is present in the substance, and
other experiments prove that no oxide of nitrogen exists in it; it contains no
oxalic or other organic acid, for when its salt is boiled with chloride of gold,
the latter is not reduced.
When heated to redness with oxide of copper, it gave a mixture of
nitrogen and carbonic acid, in the exact proportion of 1 volume of the
former, to 5 of the latter. This was a constant result, and in no case was any
sulphuric or muriatic acid left in the copper. 0.0625 grammes of the
substance thus decomposed, gave 45 cubic centimeters of the mixed gases,
estimated at 0° C. (32° F.) and the pressure of 28 inches of mercury,
according to which the acid would be composed of carbon 32.392; nitrogen
15.2144; oxygen 52.3936 per cent. From the mean of several experiments,
it appeared that the following might represent the composition correctly.—

12 12 atoms of carbon 93.75 or 31.5128

2 12 " azote 43.75 " 14.7060
16 " oxygen 160.00 " 53.7812
297.5 100.
100 parts of the acid neutralize a quantity of base equivalent to 3.26 of
oxygen, which is to the oxygen of the acid, as 1:16; the equivalent number
of the acid derived from the analysis of the [p212] barytic salt was 306.3; by
adding only 14 per cent. to the quantity of baryta obtained in the experiment,
297.5, or the number expressed by the above formula, would be obtained.
When a salt of potash or baryta was decomposed by oxide of copper and
heat, the quantity of carbonic acid produced was a little short of five times
the quantity of nitrogen; but, upon adding that retained by the alkali or
earth, the proportion became exactly the same as in the former cases.
Welter’s bitter principle was prepared by acting on silk with ten or twelve
times its weight of nitric acid. The liquid, slightly coloured at first, acquired
a deep yellow upon adding water. It was neutralized by carbonate of potash
whilst hot, and left to cool, and the salt of potash thus obtained,
decomposed by muriatic, nitric, or sulphuric acid. This acid, crystallized
like that from indigo, formed the same salts, and was composed in the same

manner. Silk furnishes much less of the substance than indigo. Dr. Liebeg
has called this substance carbazotic acid. The most important salts formed
by it have the following properties:—
Carbazotate of Potash—crystallizes in long yellow quadrilateral needles,
semi-transparent and very brilliant; it dissolves in 260 parts of water at 59°
F., and in much less, boiling water: a saturated boiling solution becomes a
yellow mass of needles, from which scarcely any fluid will run. Strong
acids decompose it; yet when an alcoholic solution of carbazotic acid is
added to a solution of nitre, crystallized carbazotate of potash, after some
time, precipitates.—Alcohol does not dissolve it. When a little is gradually
heated in a glass tube, it first fuses, and then suddenly explodes, breaking
the tube to atoms; traces of charcoal are observed on the fragments. This
salt precipitates a solution of the protonitrate of mercury, but not salts,
containing the peroxide, or those of copper, lead, cobalt, iron, lime, baryta,
strontia, or magnesia. The slight solubility of this salt supplies an easy
method of testing and separating potash in a fluid. Even the potash in
tincture of litmus may be discovered by it; for, on adding a few drops of
carbazotic acid, dissolved in alcohol, to infusion of litmus, crystals of the
salt gradually separated. The saturated solution of the salt at 50° F., is not
troubled by muriate of platina. The salt contains no water of crystallization.
It was analyzed by converting a portion of it into chloride of potassium by
muriatic acid: its composition is,—
Carbazotic acid 83.79
Potash 16.21
100.00

Carbazotate of Soda—crystallizes in fine silky yellow needles, having
the general properties of the salt of potash, but soluble in from 20 to 24
parts of water, at 59° F.
Carbazotate of Ammonia forms very long, flattened, brilliant, [p213]
yellow crystals, very soluble in water. Heated carefully in a glass tube, it
fuses, and is volatilized without decomposition; heated suddenly, it inflames
without explosion, and leaves much carbonaceous residue.
Carbazotate of Baryta, obtained by heating carbonate of baryta, and
carbazotic acid with water. It crystallizes in quadrangular prisms of a deep

colour, and dissolves easily in water. When heated, it fuses, and is
decomposed with very powerful explosion, producing a vivid yellow flame.
The explosion is as powerful as that of fulminating silver; a solution of
chloride of potassium to which carbazotate of baryta has been added,
produces a precipitate of the potash salt, and not more than 1 12 per cent. of
potash remains in solution. 100 parts of the crystallized salt contain,—
Carbazotic acid 69.16 oxygen of the acid 16
Baryta 21.60 oxygen of the earth 1
Water 9.24 oxygen of the water 8
100.00

Carbazotate of Lime, obtained like the salt of baryta, forms flattened
quadrangular prisms, very soluble in water, and detonating like the salt of
potash.
Carbazotate of Magnesia forms very long indistinct needles, of a clear
yellow colour; is very soluble, and detonates violently.
Carbazotate of Copper, prepared by decomposing sulphate of copper by
carbazotate of baryta: it crystallizes with difficulty, the crystals being of a
fine green colour; it is deliquescent; when heated, it is decomposed without
explosion, and even without inflammation.
Carbazotate of Silver.—Carbazotic acid readily dissolves oxide of silver,
when heated with it and water; and the solution, gradually evaporated,
yields starry groups of fine acicular crystals of the colour and lustre of gold;
the salt dissolves readily in water; when heated to a certain degree, it does
not detonate, but fuses like gunpowder.
Proto-Carbazotate of Mercury, obtained in small yellow triangular
crystals, by mixing boiling solutions of the carbazotate of potash or soda,
and proto-nitrate of mercury. It requires more than 1200 parts of water for
its solution: for its perfect purification, it should be heated with a solution
of chloride of potassium, the insoluble portion separated whilst the liquid is
lost, and the peculiar salt allowed to deposit as the temperature falls. When
heated, it behaves like the salt of silver.
All these salts detonate much more powerfully when heated in close
vessels, than when heated in the air; and it was a curious thing to observe,

that those with bases yielding oxygen most readily, were those which
exploded with least force. By heating some of the salts previously mixed
with chloride of potassium, &c., to retard the action, it appeared that no
carbonic oxide, but only carbonic [p214] acid and azote were evolved during
their decomposition by heat.
On the Bitter Principle from Aloes.—Upon distilling 8 parts of nitric acid
from 1 part of the extract of aloes, and adding water to the remaining fluid,
a resinous reddish yellow substance precipitated, which, by washing,
became pulverulent—it was discovered by M. Braconnot. Upon
evaporating the liquid separated from the precipitate, it gave large yellow
rhomboidal crystals, not transparent, and but slightly soluble. These
crystals, at first mistaken for a particular substance, were soon found to be a
combination of oxalic acid with the bitter of aloes. The bitter substances of
aloes dissolved in 800 parts of water, at 59° F., but in a smaller quantity of
boiling water. This solution has a superb purple colour. Silk boiled in it
acquired a very fine purple colour, on which neither soap nor acids effected
any change, except nitric acid; this changed the colour to yellow, but it was
restored simply by washing in water. All shades may be given to this colour
by proper mordants. Wool is dyed black in a peculiarly beautiful manner, by
the same process, and light has no influence on the colour. Leather acquires
a purple colour; cotton, a rose colour; but the latter will not resist soap. Dr.
Liebeg thinks that this is the only substance from which a permanent rose
dye for silk may be expected.—Ann. de Chimie, xxxv. 72.

25. On the Existence of Crystals of Oxalate of Lime in Plants.

—M. Raspail has read a memoir to the Academy of Sciences, to prove the
analogy which exists in arrangement between the crystals of silica, which
are found in sponges, and those of oxalate of lime occurring in the tissue of
phanerogamous plants.
The latter crystals were observed, for the first time, by Rafn and Jurine,
who regarded them as organs of which they knew not the use. They were
then observed by M. de Candolle, who called them raphides, and gave a
figure of them, which, however, is inaccurate. These crystals are really very
regular tetraedrons. In many plants, as orchis, pandanus, ornithogalum,