^B! »w.n-.>. ->it0 * . 496
On the Aurora Borealis of the 7th of January, 1831. By Dr. MOLL,
of Utrecht . "v * . . . . .519
Observations on the Aurora Borealis of the 7th of January, the llth
of January, and the 7th of March, 1 83 1 . By the Hon. CHARLES
HARRIS ........ 522
On the Height above the Surface of the Earth of a Luminous Arch
of the Aurora Borealis, on the 7th of January, 1831. ByS.
H. CHRISTIE, Esq., M.A., F.R.S., &c. . . . .525
On Elaterium ; and a New Principle obtained from it by Analysis.
By HENRY HENNELL, F.R.S., M.R.I., Chemical Operator,
Apothecaries' Hall • /«;. . . ^ * .••••) . . 532
Contributions to the Physiology of Vision. No. II. . . 534
On the Ripple-Marks and Tracks of certain Animals in the Forest
Marble. By G. POULETT SCROPE, Esq., F.R.S., F.G.S., &c. . 538
11 CONTENTS.
Page
Proceedings of the Royal Institution of Great Britain . .547
Proceedings of the Academy of Sciences in Paris . . .558
ANALYSIS OF BOOKS, AND SELECTIONS FROM THE TRANSACTIONS
OF SCIENTIFIC SOCIETIES.
Life of Sir Humphry Davy, Bart., LL.D. . . . .571
Acta Academiae Caes. Leop. Carol. Naturae Curiosae Bonnae . 585
Memoirs of the Institute of France . . . .595
FOREIGN AND MISCELLANEOUS INTELLIGENCE,
§ 1. —MECHANICAL SCIENCE.
1. Stiffness and Strength of Timber .... 599
2. Proportion between the Metre and English Yard . . ibid.
3. On the Velocity of an Elastic Fluid which flows from a Reservoir into
a Gasometer ...... ilrid.
4. On the Discharge of a Jet of Water under Water (R. W. Fox, Esq.) ibid.
5. Optical Deception upon the Liverpool and Manchester Rail Road 600
6. A Barometer of a new Construction (Proposed by M. Kupffer.) . 601
7. Occultation . . . . . . . ibid.
8. Pendulum Observations ...... 602
9. Dip of the Magnetic Needle at St. Petersburgh ... 604
10. On the Direction and Intensity of the Magnetic Force at St. Peters-
burgh (M. Erman) ...... ibid.
11. Variation of the Needle ..... 607
12. On the Figure of the Magnetic Equator .... ibid.
13. New Dipping Needle ...... 608
14. Powerful Electro-Magnets . . . .609
15. On the Intensity of the Earth's Magnetism (Kupffer) . . 610
§ II.— CHEMICAL SCIENCE.
1. Matteuci on the Origin of the Action of the Voltaic Pile . . 612
2. Conducting Powers of Liquified Gases (K. T. Kemp) . .613
3. Generation of Steam by Heated Metal . . . ibid.
4. On the Preparation of lodic Acid (Serullas) . . . 614
5. On the Precipitation of the Vegeto- Alkalies by lodic Acid (Serullas) 615
6. On the Action of Bromic and Chloric Acids on Alcohol (Serullas) ibid.
7. On Perchloric Acid and its Facil Formation (Serullas) . . 616
8. On the Spontaneous Inflammation of Pulverized Charcoal (Aubert) . 617
CONTENTS. ill
Page
9. Power of Carbon to destroy the Bitterness of certain Bodies ••>-» 619
10. Method of preparing Selenium from the Sulphuret (M. Magnus) . 619
11. On the Compounds of Ammonia with Anhydrous Salts (H. Rose) 620
12. Test of the Protoxide and Peroxide of Iron (Berzelius) « ,. 624
13. A new Metal Vanadium, associated with Iron (Sefstrom) . ' , 625
14. Combustion of an Alloy of Tin and Lead (R. W. Fox) . . 626
15. Vauquelin's Process for obtaining Metallic Chromium ,•» • ^'^
16. On the Absorption of Oxygen at High Temperatures, by Silver
(Gay-Lussac) w { ; i . U*T^' »*>"' 627
17. Robiquet on a new Metallic Dye ..... 628
18. Purple Precipitate of Silver, Gold, &c. &c. ?"™' "*", »,., . ibid.
19. (Enometeror Alcohometer (M. Emile Tabarie) . , . 629
20. On the Manufacture of Sulphuric Ether (C. Wittstock) . ibid.
21. On Columbine ; a New Vegetable Principle (M. Wittstock) . 630
22. On the Composition of Camphor and Camphoric Acid (J. Liebig) 631
23. Use of Mica in minute Chemical Analyses . . 633
24. On Perforating and Cutting Glass, Earthenware, &c. (Mr. Marsh) . ibid-
§ I II. —NATURAL HISTORY, &c.
1. Circulation of Fluids in Vegetables . . . .635
2. Structure of Leaves ...... 636
3. Germination of Seeds at the Surface of Mercury . ' i' • . 637
4. Fertilization of Plants . . ;ov '; . . ibid.
5. Structure of the Radish Root . fo*?^' . . . 638
6. Russet in Apples . . . *• y*- - . >/. 3* • Hid.
7. Medicinal Use and Effect of the Ava Root . i ' 3«jf*>-« ! &V" 639
8. Mexican Domestic Bees. (Melipona Beechei) . g»--t . 640
9. Mean Meteorological Results . . . . 641
10. Climate of England. ...... 642
11. On the Earthquake at Odessa on the 26th of November, 1829
(M.Hauy) . . . . #%> ., . 64a
12. Geography of Siberia .... ,.i*l..:.! ;..'.,. 644
ERRATA IN No. III.
Page Line Pajrc Line
320 4 from bottom, for Chartres read 330 25 from top, for Tanz read Jansr.
Castres. ib. 2 from bottom, for Tanz read Jansz.
325 5 from \witom, fur vitro-crystal lines 331 6 from top, for Borel rend Boreel.
read vitrocnstallincs. 332 5 from top, for Borel read Boreel.
329 16 from top, for Bussi read Russii. ih. 1 from bottom, for that read thus.
ib. 22 from top,/or Teannin read Jeannin. ib. 1 from bottom, for produced read pro-
ib. 23 from top, for Busbi read Russi. cured.
ROYAL INSTITUTION OF GREAT BRITAIN,
4lh April, 1831.
THE WEEKLY EVENING MEETINGS of the Members of the Royal
Institution will be resumed on Friday the 15th instant, at half-past Eight o' Clock,
and will be continued on each succeeding Friday evening till the end of the
Season.
The following are the Arrangements of the Lectures which are to be
delivered on each day at Three o' Clock in the Afternoon : —
CHEMICAL AND NATURAL PHILOSOPHY. By MICHAEL FARADAY,
Esq., F.R.S., F.G.S., Corr. Memb. Royal Acad. Sciences Paris, Director of the
Laboratory of the Royal Institution, &c. &c. To commence on Thursday, the
1 4th instant, and to be continued on each succeeding Thursday till the 5th of
May. The following are the Subjects of the Course : — April 14th, Optical Decep-
tions— April 21st, Lithography — April 28th, Flowing of Sand— and May 5th,
Caoutchouc.
GEOLOGY. On some of the most important points in Geology. By THOMAS
WEBSTER, Esq., F.G.S. To commence on Saturday, the 16th of April, and to
be continued on each succeeding Saturday till the 21st of May.
POETRY AND THE POETS. By JAMES MONTGOMERY, Esq., Author of
' The World before the Flood,' f Pelican Island,' &c. To commence on Tuesday,
the 26th of April, and to be continued on each succeeding Tuesday till the com-
pletion of the Course, on the 31st of May.
ACOUSTICS. By ROBERT WILLIS, M.A., F.R.S., Fellow of Caius College,
Cambridge. To commence on Thursday, the 12th of May, and to be continued
on each succeeding Thursday till the completion of the Course, on the 1 6th of
June.
BOTANY. On Vegetable Physiology and Botany. By JOHN LINDLEY, Esq.,
F.R.S. and F.L.S., Prof, of Botany in the University of Lond., and Assist. Sec.
Hort. Soc. To commence on Saturday, the 28th of May, and to be continued on
each succeeding Saturday till the completion of the Course, on the 18th of June.
The Sons and Daughters of the Members of the Royal Institution, under
Fifteen Years of Age, may be admitted on payment of half the sum for each
Course.
Syllabuses of the Lectures may be obtained at the Royal Institution.
JOURNAL
THE ROYAL INSTITUTION
OF
GREAT BRITAIN.
ON CERTAIN PHENOMENA RESULTING FROM THE
ACTION OF MERCURY UPON DIFFERENT METALS.
BY J. F. DANIELL, F.R.S., AND M.R.I.
E results of the following experiments on the action of
mercury upon different metals may probably be considered
interesting; not only on account of the novelty of the facts,
which have been hitherto, I believe, unnoticed, but from the
relation in which some of them may be found to stand to the
laws of molecular attraction.
EXPERIMENT I.
A piece of flexible metallic tube, which is composed of an
alloy of tin and lead, was partly immersed in mercury con-
tained in a wine-glass. In the course of a few days it was exa-
mined, and found studded with brilliant metallic crystals, in a
line coincident with the level of the fluid. After this exami-
nation, it was replaced and left undisturbed for six weeks : at
the expiration of which period it was carefully lifted out of the
mercury ; and a considerable groupe of well-defined crystals
were found loosely adherent to its upper part, and many similar
ones floating upon the surface of the mercury. Their form
was that of hexahedral plates variously modified ; some of them
were above one-tenth of an inch diameter, and their lustre was
white and silvery. By placing them in a small inverted cone
of paper, perforated at its apex, the fluid mercury drained from
VOL. I. OCT. 1830. B
S Mr. Daniell on the Action of Mercury
them, and they were left in nearly a dry state. The tube was
dissolved away at its lower end to a thin edge, and the action
of the mercury had evidently decreased as it ascended : the
upper part to which the crystals were attached was but little
acted upon, so that, in its whole length, it gradually tapered
downwards. The substance of the metal, even above the part
immersed, was saturated with mercury, and had become very
brittle.
Hence it appears that the action of the mercury upon the
alloy was, first to saturate its pores and disintegrate its sub-
stance, forming a brittle, uncrystallized compound which it
must have subsequently dissolved. The amalgam thus pro-
duced, being of less specific gravity than the fluid metal, floated
to its surface, where the attraction of cohesion between the par-
ticles of the compound, being greater than the attraction which
held them in solution in the fluid, caused them to crystallize.
I have formerly * remarked, that if a mass of any soluble salt
be carefully suspended in water, it will be more acted upon at
its upper than its lower end, and will assume, more or less, the
form of a cone, with the apex at the surface of the liquid. The
particles of water which are in immediate contact with the
salt, combine with a portion of it, and thus becoming speci-
fically heavier than the remainder, sink to the bottom of the
vessel ; others succeed and follow the same course. A layer
of saturated solution is thus deposited, which increases in
depth as the process advances, protecting in its rise that part
of the mass which is covered with it from further action. In
the present instance the process is directly the reverse : the
solvent, by union with the solid, becomes specifically lighter,
and the saturated solution is first formed upon the surface ; and
the action continuing longest at the bottom of the mass, a cone
is produced with its apex downwards.
EXPERIMENT IT.
A piece of pure tin, in the usual form of closely- aggregated
imperfect prisms, in which it is found in commerce, was partly
immersed in mercury, and left undisturbed for a month. Upon
* Journal of the Royal Institution, vol. i,, p. 24, 1st Series,
upon different Metals. 3
examination, a large cluster of crystals, similar to the preceding,
was found adhering to its upper part, and others floating
upon the liquid. They were not quite so large as the first;
but bore very distinctly the form of six-sided plates. The
whole mass was thoroughly saturated with mercury, but had
been more acted upon at the bottom than the top of the portion
immersed. At the lower end, the prisms had the appearance
of being more detached from one another than in their original
state, from cracks which had taken place in the metal ; and
which conferred upon their extremities the semblance of imper-
fect pyramids. Several deep clefts also had been formed along
the more prominent edges of the mass.
EXPERIMENT III.
A small bar of lead was plunged, for about half its length,
into some mercury contained in a test-tube. Having been left
undisturbed for ten days, it was carefully lifted out and exa-
mined. A bundle of very delicate, silver- white, feathery crystals
was found loosely adhering to it, on a line with the surface of
the fluid. Their form could not be accurately determined, but
they resembled a heap of frosty particles swept together on a
pane of glass ; and their minute prisms appeared to be attached
together at angles of sixty degrees. The bar had been most
acted upon at its lowest extremity : it was thoroughly impreg-
nated with mercury throughout its substance, but had not
totally lost its ductility. After the operation, the tin crumbled
to pieces under a slight blow of the hammer, but the lead could
be flattened into a plate.
EXPERIMENT IV.
A bar of zinc was treated in the same way, and for a like period.
It was found, upon examination, studded throughout the whole
length which had been immersed with very bold crystals, of
the form of hexahedral plates, which increased in quantity and
size from below upwards. The bar tapered downwards to a
point, and was more unequally acted upon than the former
metals, its surface being rough, and corroded into cavities.
Some of the crystals adhered very strongly to the surface, and
B 2
4 Mr. Daniell on the Action of Mercury
some of them had the appearance of being partly imbedded
in the bar, or dissected from its substance. They were of a
darker hue, and more brilliant than the crystals from lead and
tin.
EXPERIMENT V.
A bar of fine silver was partly immersed in mercury, as in
the preceding cases : at the expiration of a fortnight no crystals
had been formed. The mercury had entered into its substance,
but upon trial it had not lost its malleability. It was replaced,
and at the end of six weeks had not apparently changed its
characters. The test-tube, with its contents, was now heated
till the mercury began to boil, and was set by to cool gradu-
ally. In twenty-four hours' time the bar was again examined,
and a bundle of very fine needle-crystals was found clustered
round the part which was just intersected by the surface of the
liquid.
In this case, the affinity of the mercury for the silver enabled
it to penetrate its pores, and thoroughly to saturate it, but its
attraction for the resulting compound was not sufficiently
strong to allow it to overcome the remaining attraction of
aggregation, and dissolve the solid at the ordinary temperature
of the air. When assisted, however, by heat, the solution
was effected, and the compound, as in the former instances,
being specifically lighter than the pure fluid, floated to the top,
and crystallized.
EXPERIMENT VI.
A small portion of a bar of fine gold, about an inch and a
half in length, was put into mercury, in which, of course, it
sank, from its greater specific gravity. The fluid very quickly
penetrated it, and completely destroyed its yellow colour. In
a month's time it retained its malleability, and a part of it was
flattened under the hammer into a very thin plate. Its sur-
face was studded with very minute crystals, whose dimensions
were too small to be determined. The gold was then heated
in the mercury to the boiling point of the latter, when it was
completely dissolved, and a pasty amalgam formed.
There can be no doubt tlaat in all these instances the mer-
upon different Metals. 5
cury formed definite solid compounds with the several metals,
which were capable of being held in solution by an excess of
the fluid ; but were also capable, in favourable circumstances,
of separating from it, and crystallizing in peculiar forms.
Whether, at the same time, any other compound may have
been formed of an essentially liquid nature, I have not ex-
amined; but I may here remark, that the manufacturers of
looking-glasses have made the observation, that the mercury
which is pressed out of the tin amalgam, which they apply to
the backs of their plates, is in as pure a state as that which
they originally make use of.
EXPERIMENT VII.
A square bar of tin, about five inches long, and whose sides
were a quarter of an inch wide, was laid horizontally in a card-
tray, and just covered with mercury. To render the action as
equal as possible, it was frequently turned upon its different
sides, and examined. At the expiration of twenty-four hours,
minute fissures began to appear along all its lateral and termi-
nal edges. The process was continued, and the cracks widened,
until, on the third day, they opened to such a degree as to
shew that the bar was resolved into four equal trihedral, rect-
angular prisms, with two equal angles. They were readily
separated from each other by the point of a penknife, and two
similar pyramids, whose angles at their bases were 45°, were at
the same time detached. This groupe is accurately represented
in their relative positions, a little separated, at Fig. 1, Plate I.
a, a, a, a are the small triangular prisms, which, when in contact,
made up the original square bar ; and b represents one of the
terminal pyramids. All the angles were as sharp and perfect,
and the faces as neat, as if they had been carved with tools ;
and when brought into contact with one another, they adhered
together with some force, from the cohesive attraction of a little
mercury which hung about them. This experiment I imme-
diately repeated, and obtained the same very remarkable results.
I was at first induced to consider this singular phenomenon
as dependent upon the original structure of the bar, from the
consideration of the following facts, which are well known to
6 Mr. Daniell on the Action of Mercury
most workers in the metals, and which I have myself verified
by experiment.
No metal can be hammered round upon an anvil, either hot
or cold. Blacksmiths very well know that they cannot forge a
round bar of iron ; and I have myself seen a rod of the best
iron which, properly heated, could be extended indefinitely,
when hammered square or flat, split into fibres, and become
perfectly disintegrated after a few blows given equally round.
When it is desired to give a round form to any part of a square
bar of iron, it is effected by forcing it, while hot, into a kind
of fornij or mould, of the required dimensions ; or, as is well
known, it may be extended in a cylindrical form to almost any
degree, by the equal pressure applied in the process of wire-
drawing. If square bars of gold, silver, or copper^ the most
malleable of all the metals, be hammered upon the edges, and
the blows repeated round, so as to give them a cylindrical
shape, they soon become what is technically termed rotten, and
break into fibres, while the bars may be extended under the
hammer to any degree, by blows directed parallel to their ori-
ginal faces, or may be beat into leaves of almost inconceivable
thinness, if the force be directed upon one surface only. The
less malleable metals, lead, brass, and tin, become even sooner
disintegrated when hammered round ; and, although they are
capable of considerable extension, when hammered square, they
ultimately split along the edges in a manner very similar to
the disintegration which I have just described as resulting from
the action of mercury upon the tin bar.
It is also worthy of observation, that the metallic bars, when
hammered square, generally assume a rhomboidal, rather than
a perfectly rectangular form, and that the fissures take place
indifferently upon all the angles ; but if the hammering be
continued, they sometimes split into two, in the direction of
one of their diagonals, before the separation takes place in the
direction of the other. I have not been able to satisfy myself
whether this tendency to the rhomboidal form results from any
inequality in the blow of the hammer, producing an inclination
of the planes of compression to one another ; or whether it may
be referred to the forms of the ultimate particles of the metals ;
but I have ascertained that it takes place even when the greatest
upon different Metals. 7
pains are taken to keep the face of the hammer parallel to the
surface of the anvil ; and that it can only be counteracted, when
required, by directing a blow from time to time upon the acute
angle. To determine, if possible, whether any connexion sub-
sists between these results of the direct application of mecha-
nical force to the metals, and the structure of the bars of tin
developed by the action of mercury, as just described, I insti-
tuted the following experiments.
EXPERIMENT VIII.
A bar of tin, of about the same dimensions as the last, which
had assumed the rhomboidal form during the process of ham-
mering, from the original cylindrical shape in which it had
been cast, was treated with mercury in the manner described
above : it was resolved, as before, into four rectangular trihe-
dral prisms, but with two unequal angles, corresponding to
the bisected angles of the rhomboid.
EXPERIMENT IX.
The tin bars upon which the previous experiments were made
had been shaped by the hammer, and I was desirous of ascer-
taining whether the forces which had been applied had in any
way disposed their particles to assume the structure which had
thus been developed. For this purpose, a bar was cast, in a
mould, of nearly the dimensions of that employed in Exp. vii.
and was treated with mercury in the same manner. The four
trihedral prisms, with their two pyramids, were formed as
before ; but the clefts and the planes of junction were not as
neat as in the foregoing instances. This seemed to be owing
to the angles of the original bar not having been so sharp as
when formed by the hammer, but having necessarily come
rounder from the mould, and presenting a surface to the action
of the mercury.
EXPERIMENT X.
A cast cylinder of. tin, five inches long, and a. quarter of an
inch in diameter, was substituted for the square bar in the
8 Mr. Daniell on the Action of Mercury ,
experiment : at the end of three days, during which it was
frequently turned, the terminal edges were cleft all round, and
irregular cracks appeared upon various parts of its surface.
Two solid pieces, approaching the hemispherical form, but
much flatter, were extracted from the ends by the point of a
knife, and two cup-like cavities were formed in the bar. By
introducing the edge of the knife into the cracks upon the sur-
face, its substance was broken away in parts, and a concentric
arrangement of the amalgam disclosed round a central nucleus 5
the appearance of which is represented at Fig. £. The out-
side coating, 6, 6, was perfectly brittle, but the centre
rod, a, a, still partially retained its malleability, and could
be bent two or three times backwards and forwards, before it
broke.
EXPERIMENT XI.
Another bar of tin was cast, of the form and dimensions of
half the preceding cylinder, divided longitudinally. Its ap-
pearance, after being treated with mercury as described, is
exhibited at Fig. 3. Its two lateral edges were sharply cleft
asunder, as at a, a, and some irregular cracks appeared upon
its round surface. Part of the substance of the amalgam was
broken away, as shewn at bt when a centre cylindrical rod
appeared, and the concentric arrangement was apparent, as in
the last experiment.
EXPERIMENT XII.
Having cast a cylinder of tin, similar to that employed in
Exp. x., one half of it was made square by the file, and the
whole was then submitted to the action of mercury as before.
The cleavage down the lateral edges, which were very sharp,
was perfect, and a most beautiful pyramid was formed at the
square end. The cylindrical portion of the bar was irregularly
cracked, and there seemed to be a tendency of the clefts in the
square edges to continue their course into this part. These
results are represented at Fig. 4; a is the terminal pyramid,
by b the cleft upon one of the edges of the square bar ; c, c the
cylinder.
upon different Metals. ' 9
EXPERIMENT XIII.
I cast a square bar of tin, of similar dimensions to that which
I employed in Exp. ix. One half of its length was hammered
upon the edges till four new planes were formed in their places,
and the square reversed from its original position. Thus both
ends of the bar were still square, but the edges of one half were
in the direction of the planes of the other half, and a small
intermediate portion was irregularly octangular. The whole
was soaked in the shallow bath of mercury. The cleavage upon
the edges of the hammered half was perfect, and the trihedral
prisms and terminal pyramid very distinct. The edges of the
cast portion were not cleft, but the sharp divisions of the ham-
mered edges were continued down its faces, in ragged, irregular
cracks, which gaped particularly near the point of junction.
This end, therefore, had a tendency to separate into four tetra-
hedral prisms, and the force was so great, that they broke off
near the point of junction of the two parts of the bar, and
ultimately assumed the appearance represented at Fig. 5. The
sharp and even cleft upon one of the edges of the hammered
portion is exhibited at a, a, and the ragged crack upon the
corresponding face of the cast part at b b, gaping at the point
of fracture, c, c, as if rent asunder with great violence.
I attempted in vain to produce analogous results with bars
of lead, brass, gold, silver, and zinc, for in none of these in-
stances could I obtain evidence of the action of any mechanical
force acting upon the particles of the metals ; although their
union with the mercury was, to all appearance, as intimate as
that of tin. No cracks or disruptions appeared in any of them.
The surfaces of the four first remained perfectly smooth and
continuous, but that of the last was corroded into cavities.
There can be little doubt, I think, that the disruptive force
which effected the disintegration of the tin bars, in the manner
above described, was the powerful contraction of the integrant
particles of the metal, in the act of combining with the mercury.
It has, indeed, been proved that the amalgam hence resulting
is of considerably greater density than the mean of its compo-
nent parts, and that such approximation of molecules must,
10 Mr. Daniell on the Action of Mercury
therefore, take place ; the balance of force which determines
its particular direction in the instances pointed out, forms an
interesting subject of investigation, which, together with the
cleavage and dissection of crystals, and the manner in which
they are affected by light and heat, may ultimately contribute
to the explanation of the laws of molecular attraction.
I shall conclude this paper with the result of some experi-
ments upon the mutual action of mercury and platinum.
EXPERIMENT XIV.
There is no apparent action whatever between mercury and
a bar of platinum, at the common temperature of the atmos-
phere ; but when exposed together for a short time to the
boiling point of the former, the latter becomes superficially
coated with the fluid. The combination is so slight, that the
mercury may easily be wiped off mechanically, as water from
wet glass. Platinum, which has been kept constantly wetted
with mercury for six years, has not become disintegrated, or in
any way changed its properties.
EXPERIMENT XV.
A few grains of spongy platinum, formed from the ammonio-
muriate, were violently agitated with mercury and a few drops
of water in a test-tube : a kind of thick scum, or semifluid
amalgam, speedily collected upon the surface, from which the
still fluid metal could easily be poured off.
EXPERIMENT XVI.
The foregoing experiment was repeated ; but the water was
acidified with acetic acid. The test-tube was five inches long,
and about half an inch diameter. The mercury occupied
about an inch, and the weak solution of the acid about half an
inch of its depth. The platinum was thrown in, and the whole
shaken together for a short time ; when the tube became filled
with an amalgam, of the consistence of soft butter. When the
tube was upset, a very few drops of fluid mercury ran out of it ;
and when the amalgam was shaken out into a saucer, it retained
its consistence for many weeks. It possessed a dullish metallic
hue, like that of lead which has become tarnished ; and very
upon different Metals. H
much resembled the amalgam formed by the electrization of
mercury in contact with ammonia.
The experiment was frequently repeated, sometimes with the
substitution of some neutral salt for the acid, and always with
similar results.
When the amalgam was laid upon filtering paper, the mois-
ture was gradually absorbed and evaporated, and the mercury
returned to the fluid state.
EXPERIMENT XVII.
The experiment was varied by filling a tube, which was
some inches longer, with the weak acid solution ; and after the
formation of the amalgam by agitation, inverting it in a cup of
mercury. Minute bubbles of gas were immediately seen rising
from the amalgam through the fluid, and collecting in the
upper part of the tube. Upon close examination, particles of
the spongy platinum could be discovered between the sides of
the glass and the mercurial paste, round which bubbles of
gas gradually accumulated, which gave the whole a honey-
combed appearance. These, as they increased in size, slowly
crept up the sides of the tube, till, reaching the fluid, they
rapidly ascended to the top. In twelve hours' time, nearly the
whole of the liquid had been expelled from the tube, and when
a light was applied to the gas it exploded.
Some of the acetic solution, which had been frequently em-
ployed in repetitions of the experiment, was slowly evaporated,
and afforded crystals of prot-acetate of mercury.
EXPERIMENT XVIII.
I endeavoured, in vain, to produce analogous results, by
agitating amalgam of gold and other amalgams with diluted
acetic acid and solutions of neutral salts. No action was
apparent, and in no instance was anything like the frothy amal-
gam produced.
Hence it appears that, when minutely divided platinum is
agitated with mercury, and moisture is present, an electrical
action takes place, which, when heightened by the addition of
a diluted acid, or the solution of a neutral salt, is sufficiently
energetic to decompose water and evolve hydrogen : the oxygen
12 Mr. Daniell on the Action of Mercury, fyc.
at the same time combines with the mercury, and a solution is
effected by the acetic acid, which its unassisted affinity could
not have produced. This action appears to be of the same
nature as that described by Mr. Faraday *, in his account of
the Alloys of Steel ; during his experiments upon which, he
found that steel, alloyed with an hundredth part of platinum,
was acted upon by dilute sulphuric acid, with infinitely greater
rapidity than the unalloyed steel, and that an acid, which
scarcely touched the pure steel, dissolved the alloy with ener-
getic effervescence.
It also appears that this electrical action communicates an
adhesive attraction to the particles of the metal, by which the
particles of liquid and aeriform bodies are entangled and re-
tained, a kind of frothy compound formed, and the fluidity of
the mercury destroyed. The appearance of this amalgam is
so very like that of the ammoniacal amalgam formed by ex-
posing a solution of ammonia in contact with mercury to the
influence of the Voltaic pile, or when an amalgam of potassium
and mercury is placed upon moistened muriate of ammonia,
that it is impossible not to be struck with the resemblance. I
am inclined, indeed, to believe, that the production of the latter
may be explained upon the same principles as that of the for-
mer. When the effect is produced by the direct application of the
electrical current, by means of the battery, it ceases the moment
the connexion between the poles is broken ; and when brought
about by the agency of the amalgam of potassium, the elec-
trical action is doubtless excited by the contact of the two
dissimilar metals, and the frothy compound lasts no longer than
the existence of the potassium in the metallic state. In the
action which I have just described, bet ween mercury and finely-
divided platinum, the permanence of the metals produces a
much more lasting effect, and the soft amalgam may be pre-
served for a great length of time without altering its appear-
ance. At all events, these results cannot but increase the
strong doubts which previously existed concerning the hypo-
thesis of the metallization of ammonia, and the supposed
compound of mercury and ammonium.
* Philosophical Transactions) 1822. Part II., p. 262.
( 13 )
ON THE MEANS OF GIVING A FINE EDGE TO RAZORS,
LANCETS, AND OTHER CUTTING INSTRUMENTS.
BY THOMAS ANDREW KNIGHT, ESQ., F.R.S.,
President of the Horticultural Society, &c.
TN the preparation of steel, and in the art of subsequently
forming it into cutting instruments, the British manufac-
turers are, I believe, unrivalled ; and they have probably
approximated, if they have not attained, perfection : but in
the art of giving the finest possible edge to their instruments,
when formed, I think that they have generally still some-
thing to learn ; for I hear surgeons often complaining, that
they rarely find themselves in possession of a perfectly well set
instrument ; and I have never yet, in any instance, seen a
razor come from a cutler so set that I could use it with any
degree of comfort, though I have obtained razors from many
of the most eminent manufacturers of the metropolis. The
machinery which they employ has long appeared to me to be
imperfect and uncertain in its mode of operating, and in many
respects inferior to that which I have been some years in the
habit of using, and which I shall proceed to describe.
This consists of a cylindrical bar of cast steel, three inches
long without its handle, and about one-third of an inch in
diameter. It is rendered as smooth as it can readily be made
with sand, or, more properly, glass-paper, applied longitudi-
nally; and it is then made perfectly hard. Before it is used,
it must be well cleaned, but not brightly polished, and its sur-
face must be smeared over with a mixture of oil and the char-
coal of wheat straw, which necessarily contains much siliceous
earth in a very finely reduced state. I have sometimes used
the charcoal of the leaves of the Elymus arenarius and other
marsh grasses ; and some of these may probably afford a more
active and (for some purposes) a better material ; but upon
this point I do not feel myself prepared to speak with decision.
In setting a razor, it is my practice to bring its edge (which
must not have been previously rounded by the operation of a
strop) into contact with the surface of the bar at a greater or
14 Mr. Knight on the Means of giving
less, but always at a very acute angle, by raising'the back of
the razor more or less, proportionate to the strength which I
wish to give to the edge; and I move the razor in a succession
of small circles from heel to point, and back again, without
any more pressure than the weight of the blade gives, till my
object is attained. If the razor have been properly ground
and prepared, a very fine edge will be given in a few seconds;
and it may be renewed again, during a very long period, wholly
by the same means. I have had the same razor, by way of
experiment, in constant use during more than two years and a
half; and no visible portion of its metal has, within that pe-
riod, been worn away, though the edge has remained as fine
as I conceive possible ; and I have never, at any one time,
spent a quarter of a minute in setting it. The excessive
smoothness of the edge of razors thus set led me to fear that it
would be indolent, comparatively with the serrated edge given
by the strop ; but this has not in any degree occurred ; and
therefore I conceive it to be of a kind admirably adapted for
surgical purposes, particularly as any requisite degree of
strength may be given with great precision. Before using a
razor after it has been set, I simply clean it on the palm of
my hand, and warm it by dipping it into warm water ; but I
think the instrument recommended operates best when the
temperature of the blade has been previously raised by the aid
of warm water.
A steel bar, of the cylindrical form above described, is, I
think, much superior to that of a plane surface for giving a
fine edge to a razor or penknife ; but it is ill calculated to give
a fine point to a lancet ; and I therefore cause a plane surface
to be made, a quarter of an inch wide, on one side of the bar,
by cutting away a part of its substance ; and I have found
this form to be most extensively useful.
The edge of some razors, whether formed of wootz, of mixed
metals, or of pure steel, but particularly of mixed metals, has
generally appeared to me to be more keen and active when
used a few seconds after it had been applied to the bar, than
on the following day ; and I have often seen the utmost activity
restored to the edge of such instruments, so instantaneously,
and by so apparently inadequate means, that I have been
a fine Edge to Cutting- Instruments. 16
sometimes led to suspect the operation of the bar to have been
something more than that of having worn away a minute por-
tion of the metal : but I am not disposed to offer any conjec-
tures respecting other effects which I may have conceived it to
produce.
I have in many instances been able to give a very fine edge
to razors in possession of my friends, which I could not set
tolerably well by any of the ordinary means; and I have
found that those composed of different materials could be set
with equal facility, though the sensations they excited, when
used, appeared to me to be in many instances dissimilar. The
instruments upon which I have chiefly made experiments have
come from the manufactories of Mr. Pepys. Mr. Stoddart,
and Mr. Kingsbury. The material which appeared to me to
receive that which I shall call the most eager edge (and it was
very durable) was wootz, from the manufactory of Mr. Pepys;
and that which received the smoothest edge^ and which I
thought best calculated for surgical purposes, was the mixture
of rhodium and steel ; the powers of the pure steel of Mr.
Kingsbury appeared to be intermediate : and my experience
leads me to believe that, under different circumstances, each
of these materials might be used with some exclusive advan-
tages.
ON THE PECULIAR HABITS OF CLEANLINESS IN SOME
ANIMALS, AND PARTICULARLY THE GRUB OF
THE GLOW-WORM.
BY J. RENNIE, A.M., A.L.S.
TN an excursion, for the purposes of natural history, to the
woods in the vicinity of Dartford, in Kent, the 14th of
last March, I found an insect, which I had not hitherto met
with, creeping upon the mossy trunk of an oak, which, besides,
was entwined with honeysuckle ; and, near the bottom, a fern
plant was rooted amongst the decaying bark. This insect
much resembled the female glow-worm in external appearance,
but it was considerably longer, and the colours different. Its
head, though small, was formed like those of the grubs of pre*
16 Mr. Rennie on the Cleanliness of Animals.
daceous beetles, whence I conjectured it might belong to some
of their numerous families ; but lest I might be deceived in
this, and that after all it might be a vegetable feeder, I put
some of the oak bark, moss, fern, and honeysuckle, along with
it into a collecting-box. Into the same box I afterwards put
several specimens of small snails, with pellucid shells, which I
found in the same locality — a circumstance which led me to the
discovery of one of those facts that, after eluding direct research,
are often the result of accident.
It was not till next day that I looked into the box, when
I perceived that none of the vegetable substances had been
touched, for the snails had glued themselves to the lid, ac-
cording to their usual custom when put into a dry place ; and
though the little stranger was sufficiently lively, and walked
about in all directions, nothing within reach appeared to suit
its taste. After watching it for some time, my attention was
drawn to some very singular movements which it made with
its tail, and which the reader will understand better if he has
observed how the common earwig, or the insect popularly called
the devil's coach-horse, (Goerius olens, STEPHENS,) bends up
its tail over its back, somewhat in the manner of a spaniel when
it trips along well pleased before its master. The forked tail
of the earwig, however, as well as that of the goerius, is said to
be used in assisting to unfold its long and closely-folded wings,
an operation which I have never myself witnessed ; but as
the strange insect had evidently no wings, this could not be the
design of the movements to which I have alluded. I have more
than once seen a female moth strip the down from her body to
furnish her eggs with a warm covering, for which purpose she
bent in the required directions an instrument like a pair of
tweezers, situated at the extremity of the tail ; but in the in-
stance in question this could not be the case, as there was no
down on the body : and yet, upon closer inspection, it seemed
to be pulling off something very assiduously from the parts
upon which the extremity of the tail was turned back.
There appeared to be something so uncommon in these
movements, that my curiosity was excited to observe them
more minutely ; and as the creature was not at all timid, I
could easily observe it through a glass of some power. The
Mr. Rennie on the Cleanliness of Animals.
17
caudal instrument I discovered, by this means, to consist of a
double row of white cartilaginous rays, disposed in a circle, one
row within the other ; and, what was most singular, these were
retractile, in a similar manner to the horns of the snail. The
rays were united by a soft, moist, gelatinous membrane, but so
as to be individually extensile ; one or two being frequently
stretched beyond the line of the others. The rays were also
capable of being bent as well as extended, and they could
therefore be applied to the angles or depressions of an uneven
surface.
It was not long before I convinced myself that this singular
instrument was employed by the insect for cleaning itself ; and
it would have been difficult to devise anything more effectual
for the purpose, though its action was different from all others
of this kind with which I was acquainted, inasmuch as it
operated by suction, and not as a comb, a brush, or a wiper,
of which I shall mention some examples in the sequel. It
was, moreover, furnished in the interior with a sort of pocket,
of a funnel shape, formed by the converging rays, into which
was collected whatever dust or other impurities were detached
from the body, till it could hold no more, when, by a vermi-
cular movement of the rays, the accumulated pellet was ex-
truded, and placed with great care in some place where it
might be out of the way of again soiling the glossy skin of the
insect. This skin, if I may call it so, was of a soft, leathery
appearance; exhibiting, when magnified, a minute delicate
dotting, similar to shagreen — but to the naked eye this was
not apparent.
a
a
Magnified views of the cleaning Instrument, open and closed, a, the under side of the body j
bt the cleaning instrument.
VOL, I.
OCT. 1830.
18 Mr. Rennie on the Cleanliness of Animals.
The instrument just described, accordingly, when expanded
over a portion of this shagreened surface, was subsequently
drawn out, with an evident effort, (repeated, if necessary,)
in the same way as boys draw their moist leather suckers,
when they amuse themselves in dragging stones after them.
Every particle of dust or other extraneous matter is thus
detached from the skin, and, by a peculiar movement of the
retractile rays, is lodged in the funnel-shaped pocket.
Larv of the glow-worm on a tendrilled branch, using its cleaning instrument.
This singular instrument is also used for the very different
purpose of assisting the animal to walk, and particularly to
maintain a position against gravity, which its feet are ill calcu-
lated to effect ; though its habits, as we shall presently see,
render it in some measure indispensable.
Larva walking against gravity by means of the funnel at the anus.
The interest which I began to take in the insect induced me
to endeavour to ascertain its species $ and on turning over the
Mr. Rennio on the Cleanliness of Animals. 19
voluminous work of Baron de Geer, I found it was accurately
described and figured by him as the grub (larva) of the female
glow-worm, (Lampyris noctiluca ;) but though he had bred
several of these, he does not seem to have observed their sin-
gular mode of cleaning themselves, which I have just described.
He was also unsuccessful in discovering their peculiar food. * I
know not,' says he, ' what it eats ; but the form of its teeth
would make me suppose it to be carnivorous. It lived with
me on moist earth, where I 'strewed grass and the leaves of
various plants; having remarked that it became feeble and
languishing when I failed to supply it with moisture*.1
Two of the most celebrated French naturalists of the present
day make a similar statement respecting its food. ' It is be-
lieved,' says Dumeril, ' that the glow-worms are carnivorous
in the perfect state, but that their grubs (larva) feed on vege-
tables— what, is unknown f.' ' This grub,' says Latreille,
* though furnished with strong jaws, (which would indicate
that it is carnivorous,) feeds upon grass, and leaves of various
plantsj ;' but I doubt whether this is not a hasty and un-
warrantable inference from De Geei*.
The actual food of the grub in question shews, in a very
striking point of view, the design of Providence in furnishing
it with the instrument which I have described. I was not a
little surprised one day to observe the creature moving about
with one of the little snail-shells on its head, and could not
Larva feeding on a small snail.
* De Geer, Mem. Insectes, vol. iv., p. 48.
f Diet, des Sciences Naturelles, vol. xxv., p. 21
Nouvcau Diet, d'Histoire. Naturclle, vol. xvii., 284.
C 2
20 Mr. Rennie on the Cleanliness of Animals.
conjecture what had made it take a fancy to so singular a
helmet ; but I soon perceived that it was in fact making prey
of the poor snail — having, for that purpose, thrust its narrow
extensile head half to the bottom of the shell, which it did not
quit till it had devoured the inhabitant.
It was thus proved to me that it was not a vegetable feeder,
but carnivorous ; and I subsequently found, upon trial, that
it would touch no animal except snails. Its head, from being
extensile, is well adapted for pursuing its prey to the inmost
recesses of their shells ; and its mandibles, which are curved in
form of a pair of calliper compasses, appear, as in the in-
stance of the grub of the ant-lion (Myrmeleon formicarius},
to be employed rather for sucking than for eating, though I
was unsuccessful in satisfactorily ascertaining this point.
Head of the glow-worm grub, a, the head ; b, the neck ; c, the antennae ; d, the jaws.
It is more to the present subject to mention, that the grub
cannot well devour one of its victims without being soiled with
slime ; and accordingly, after every repast, I observed that it
went carefully over its head, neck, and sides, with its cleaning
instrument, to free them from slime.
Though not directly connected with my immediate subject,
it maybe interesting to many 'readers to mention that the above
grub, as well as those observed by Baron de Geer, distinctly
proved the fallacy of the common doctrine respecting the light
of the glow-worm, which goes to maintain that it is a lamp, lit
up by the female, to direct the darkling flight of the male.
' Ce sont,' exclaims Dumeril, ' les flambeaux de 1'amour — des
phares — des telegraphes nocturnes — qui brillent et signalent au
loin le besoin de la reproduction dans le silence et Tobscurite
des nuits *.' Mr. Leonard Knapp, refining upon this notion,
conjectures that the peculiar conformation of the head of the
* bictionnaire des Sciences Naturelles, xxv. 216.
Mr. Rennie on the Cleanliness of Animals. 21
male glow-worm is intended as a converging reflector of the
light of the female, ' always beneath him on the earth.' * As
we commonly,' he adds, ' and with advantage, place our hand
over the brow, to obstruct the rays of light falling from above,
which enables us to see clearer an object on the ground, so
must the projecting hood of this creature converge the visual
rays to a point beneath */
Unfortunately for this theory, the grubs — which, being in a
state of infancy, are therefore incapable of propagating — exhibit
a no less brilliant light than the perfect insect. De Geer says
the Jight of the grub was paler, but in the one which I had it
was not so. He also remarked the same light in the nymph
state, which he describes as * very lively and brilliant ;' and, in
this stage of existence, it is still less capable of propagating
than in that of larva. * Of what use then,' he asks, ' is the
light displayed by the glow-worm ? It must serve some pur-
pose yet unknown. The authors who have spoken of the male
glow-worms say positively that they shine in the dark as well
as the females {.' These plain facts appear completely to ex-
tinguish the poetical theory. But to return to our immediate
subject.
A very remarkable instrument, which recent observations
seem to prove to be intended for a similar purpose to that of
the caudal apparatus of the glow-worm, just described, occurs
in the fern-owl, or night-jar (Caprimulgus Europaeus), popu-
larly called the goat- sucker, from an erroneous notion that it
sucks goats — a thing, which the structure of its bill renders
impossible as that of cats sucking the breath of infants, as is
also popularly believed. The bird alluded to has the middle
claw cut into serratures, like a saw or a short-toothed comb ;
the use of which structure seems to have been misunderstood
by White of Selborne.
Foot of the European night-jar, shewing the pectinated clav
Journal of a Naturalist, p. 292, first edition.
f De Geer^ Mem. iv. 44.
22 Mr. Rennie on the Cleanliness of Animals.
< If it takes/ says he, ' any part of its prey with its foot, as I
have the greatest reason to believe it does chafers, (Zantheumia
soktitialis, LEACH, MS.,) I no longer wonder at the use of its
middle toe, which is curiously furnished with a serrated claw*.'
Mr. Dillon has recently controverted this opinion ; his observa-
tions leading him to suppose that the serratures are employed
by the bird to comb its whiskers (vibrissae)-\ . Mr. Swainson,
again, a high authority on such a subject, thinks that the fact
of an American group of the same birds (Caprimulyida),
which have no whiskers to comb, and an Australian group,
which have whiskers, but no serratures on the claws, are dis-
cordant with Mr. Dillon's opinion J. It frequently happens,
however, that the most ingenious and apparently incontrover-
tible reasoning in natural history, is overturned or confirmed
by facts accidentally observed. I was, I confess, disposed to
think Mr. Dillon's opinion more plausible than true, and to
agree with White, and the learned arguments of Mr. Swainson,
till I met with some observations of the distinguished American
ornithologist, Wilson, upon some of the transatlantic species.
In his description of the whip-poor-will ( Caprimulgus vocife-
rus), he says, ( the inner edge of the middle claw is pectinated,
and, from the circumstance of its being frequently found with
small portions of down adhering to the teeth, is probably em-
ployed as a comb, to rid the plumage of its head of vermin, this
being the principal and almost the only part so infested in all
birds §.'
Of another species, called chuck- will's- widow (C. Caroli-
nensis], he says, ' their mouths are capable of prodigious
expansion, to seize with more certainty, and furnished with
long hairs or bristles, serving as palisades to secure what comes
between them. Reposing much during the heats of the day,
they are much infested with vermin, particularly about the
head, and are provided with a comb on the inner edge of the
middle claw, with which they are often employed in ridding
themselves of these pests, at least when in a state of captivity ||.'
Considering the utility of such an instrument, we may wonder,
* Nat. Hist, of Selborne, i. 160. Ed. Lond. 1825.
f London's Mag. of Nat. Hist. ii. 31. J Ibid. iii. 188.
§ Wilson's American Ornithology, v. 77. || Ibid. vi. 97.
Mr. flennie on the Cleanliness of Animals. 23
perhaps, that, besides the herons (Ardetf), no other birds are
similarly provided for attacking those troublesome insects (Ho-
maloptera, MACLEAY, Nirmida, LEACH, &c.), which often
seriously injure the vigour and health of the animal infested,
and sometimes even occasion death. On going to visit the
ruins of Brougham Castle, in Cumberland, I was struck by the
unusual tameness of a swallow (Hirundo rustica), which I
found sitting on the parapet wall of the bridge which crosses
the Emont, on the road from Penrith. Swallows are, indeed,
far from being generally shy, trusting, perhaps, to their rapi-
dity of flight should danger threaten ; but this poor swallow
allowed itself to be approached, without offering to escape. It
seemed, in fact, instinctively courting human aid, at least I was
inclined so to interpret its pitiful looks. On taking hold of it,
I found the feathers swarming with an insect (Craterina Hi-
rundinisy OLFERS) somewhat larger in size than the common
house-bug (Cimex lectularius). I took the poor bird imme-
diately to the river ; and, on being freed from its tormentors,
it flew off joyfully to join its companions. Had it been fur-
nished with a comb, like the night-jars, it would not probably
have needed my assistance.
It may not fall in the way of many of the readers of this
paper to make personal observations on the foot-comb of the
night-jar; but similar instruments, of still more ingenious con-
struction, may be inspected, by whoever will take the trouble,
in two of our most common animals — the cat and the house-fly1
(Musca domestica), both of which may very frequently be seen
cleaning themselves with the utmost care. The chief instru-
ment employed by the cat is her tongue ; but when she wishes
to trim the parts of her fur which she cannot reach with this,
she moistens, with saliva, the soft spongy cushions of her feet,
and therewith brushes her head, ears, and face, occasionally
extending one or more of her claws to comb straight any matted
hair that the foot-cushion cannot bring smooth, in the same
way as she uses her long tusks in the parts within their reach.
The chief and most efficient cleaning instrument of the cat,
however, is her tongue, which is constructed somewhat after
the manner of a currycomb, or rather of a wool-card, being
beset with numerous horny points, bent downwards and back-
24 Mr. Rennie on the Cleanliness of Animals.
wards, and which serve several important purposes, such as
lapping milk, and filing minute portions of meat from bones.
Magnified view of a portion of the upper surface of the Cat's Tongue.
But what falls chiefly to be noticed here, is its important use
in keeping the fur smooth and clean ; and cats are by no means
sparing in their labour to effect this. The female cat is still
more particular with her kittens than herself, and always em-
ploys a considerable portion of her time in licking their fur
smooth. The little things themselves, also, begin, when only
a few days old, to perform the office for themselves ; and I have
observed the half-fledged nestlings of the black cap (Sylvia
atricapilla), and a few other birds, preening their feathers as
dexterously almost as their dam herself could have done.
It requires the employment of a microscope of considerable
power, to observe the very beautiful structure of the foot of
the two-winged flies (Muscidce), which still more closely re-
sembles a currycomb, than the tongue of the cat does. This
structure was first minutely investigated by Sir Everard Home
'and Mr. Bauer, in order to explain how these insects can walk
upon a perpendicular glass, and can even support themselves
against gravity. Of the structure of the foot of flies, con-
sidered as an instrument for cleaning, I have not hitherto met
with any description in books of natural history, though most
people may have remarked flies to be ever and anon brushing
their feet upon one another, to rub off the dust, and equally
assiduous in cleaning their eyes, head, and corslet with their fore-
legs, while they brush their wings with their hind legs. In the
common blow-fly (Musca carnaria), there are two rounded
combs, the inner surface of which is covered with down, to serve
the double purpose of a fine brush, and to assist in forming a
vacuum when the creature walks on a glass, or on the ceiling of
a room. In some species of another family (^mlidce), there are
Mr. Rennie on the Cleanliness of Animals,
25
A, side view of the last joint of the leg of the blue-bottle fly (musca vomitoria.)
B, do. of the fever fly (bibio febrilis.} Both figures magnified 100 times.
three such combs on each foot. It may be remarked, that the
insects in question are pretty thickly covered with hair, and the
serratures of the combs are employed to free these from entangle-
ment and from dust. Even the hairs on the legs themselves
are used in a similar way ; for it may be remarked, that flies not
only brush with the extremities of their feet, where the curious
currycombs are situated, but frequently employ a great portion
of their legs in the same way, particularly for brushing one
another.
Birds are peculiarly distinguished for their cleanliness, which
appears to be instinctive ; that is, it becomes apparent very
soon after they are hatched, at least in those nestlings which
are at first blind ; the others (Gallina, &c.) do not so much
requireit, from their running off immediately out of the nest
after their dam. The parents of blind nestlings are particu-
larly careful in watching, after feeding, till they moot, car-
rying it off in their beaks, an office which they even perform
for the female while she is hatching. I have particularly re-
marked this in the common starling (Sturnus vulgaris), a
thing the more necessary, from the bird nestling in the holes
26 Mr. Rennie on the Cleanliness of Animals.
of trees ; and Colonel Montague observed it in the gold-crested
wren (Regulus cristatus, RAY,) in the instance of a nest of
young which were fed by the parents after being carried into a
room*. ' In birds,' says White, ' there seems to be a parti-
cular provision, that the moot of the nestlings is enveloped in
a tough kind of jelly, and therefore is the easier conveyed off
without soiling or daubing. Yet, as Nature is cleanly in all
her ways, the young perform this office for themselves in a
little time, by thrusting their tails out at the aperture of their
nests f.' Another delightful writer says, c birds are unceas-
ingly attentive to neatness and lustration of their plumage.
Some birds roll themselves in dust, and occasionally particular
beasts cover themselves with mire ; but this is not from any
liking or inclination for such things, but to free themselves
from annoyances, or to prevent the bites of insects £.'
I may be permitted to illustrate one of these remarks of Mr.
Knapp, by mentioning the fact, that in some parts of Africa
the elephant and the rhinoceros, in order to protect themselves
from flies, roll themselves in mud, for the purpose of forming
an impenetrable crust upon their skin when it becomes dry.
Their most formidable insect pest, according to Bruce, is a fly
called Tsalfaya, belonging, it would appear from the descrip-
tion, to Clairville's Haustellata. It is said not to be larger
than a common bee, but is more terrible to those two animals
than the lion himself. It has no sting, but insinuates its sucker
(haustellum) through the thickest skin, in the same manner as
our cleg (Hamatopota pluvialis, MEIGEN) does. The effects
of this sucking are such, that the part not only blisters, but
frequently mortifies, and in the end destroys the animal ; but
the coating of dried mud over the skin affords them effectual
protection, and therefore cannot be justly quoted as an instance
of their dirty habits. It is highly probable, as it appears to
me, that the proverbially unclean habits of swine may be re-
ferred to a similar origin, particularly as no animal is more
careful to have its bed clean and dry.
There is another family of animals no less repulsive to the
feelings of many people, though not proverbially dirty as the
* Ornith. Diet. Introd. f Nat. Hist. ofSetborne, i.269.
I KNAPP, Journ, of a Naturalist ,311.
Mr. Rennie on the Cleanliness of Animals. 27
swine, which I have discovered to be peculiarly cleanly ; I
refer to the several species of spiders. During the course of
a series of observations and experiments on the process by
which they can shoot lines of their gossamer silk across a brook,
or other intervening obstacle, it was indispensable that I should
pry with minute attention to their every movement ; and I
was soon struck with one which interested me not a little, in
the instance of one of the long bodied species, (Tetracjnatha
extensa, LATREJLLE.) It appeared to be mumbling, if I may
use the term, its legs between its mandibles, drawing each
leisurely along, as a dog may be seen to gnaw a bone when not
very much in earnest, but more by way of pastime than of
making a dinner. I could not at first account for this ; the
ancient naturalists, who drew largely on their imagination when
facts failed them, would at once, I have no doubt, have leapt to
the conclusion, that the spider, in default of prey, actually
devoured its own legs, as it has been asserted to do its web*.
A little attention convinced me, that the movements alluded
to were precisely1 of the same kind as the preening of birds.
Spiders have their legs more or less covered' with sparse hair,
which, being rather long and bristly * is apt to catch up bits of
their own web and other extraneous matters, and these, from
the delicacy of their semi-transparent skin, must produce un-
comfortable irritation. To free themselves from this is one of
their daily occupations ; and when a spider appears to the less
minute observer to be quite at rest, it will often be seen, on
close inspection, to be assiduously and slowly combing its legs
in the manner I have above mentioned. The term combing is
very appropriate in the instance of the common garden-spider
(Epeira diadema), which is furnished with a set of teeth some-
what in form of a comb; but it has another instrument in
addition to this, peculiarly useful in the process, consisting of a
smooth and somewhat curved horny needle, which bends over
the teeth of the comb, and holds the limb which it is dressing
more firmly down, as if, after entering it in the hair, we were
to apply a finger over the edge of one of our artificial combs.
In some other spiders (Dysdera erythrina, &c.), there is, in
the situation of the comb just described, a closely set brush of
* BLOOMFIELD'S Remcunsy vol. ii.
28 Mr. Rennie on the Cleanliness of Animals.
thick hairs, which is employed in the same way. Any person
who will take the trouble may readily verify these observations
by confining a spider in a wine-glass, placed in a saucer filled
with water, from which it cannot escape, so long as there is no
current of air to carry off a silken line for a bridge.
Those who have paid attention to ants, may have remarked
that a pair of them may be often seen touching one another with
their antenna?, and even passing their tongues over part of each
other's bodies, in the same way as they are seen to do with their
eggs, larvae, and pupae, erroneously imagined by the ancients
to be hoarded grain. The necessity which they are under of
moving these to various parts of the colony, in consequence of
variations in the weather, must often expose them (polished
though they be) to soiling; but the careful nurses instantly
remove every thing of this sort with their mandibles, or tongue
• — movements which have been misinterpreted, as licking the
pupae into shape ; as the bear is no less erroneously asserted
to do by her cubs. In all such cases, cleanliness seems to be
the chief, if not the sole, motive ; as those mutual caresses of
the working ants are, I think, for the same purpose. These,
indeed, remind me strongly of the common practice of horses
and cows of cleaning each other's necks and heads, which the
individual cannot itself reach with its tongue ; and, in the same
way, caged birds will sometimes do the friendly office to a fel-
low-prisoner, of pecking off anything extraneous adhering to
the head or the bill, where preening is impossible, and the foot
is seldom well adapted to the purpose.
Such are a few of the illustrations which have suggested
themselves to me upon this subject : should they be found
interesting, I may probably add a few more at a future op-
portunity.
Lee, Kent, 1st July, 1830.
DESCRIPTION AND APPLICATION OF A TORSION
GALVANOMETER.
BY WILLIAM RITCHIE, A.M., F.R.S.
Assoc. Mem. S. A. for Scotland, Rector of the Royal Academy of Tain.
TN a paper which appeared in the first part of the Philoso-
'• phical Transactions for 1830, 1 investigated the elasticity
of threads of glass, and applied that property to the construc-
tion of a delicate and accurate galvanometer. The instrument
then described, though sufficient for most purposes, requires
some modification to adapt it to researches of extreme delicacy.
The description of the instrument, in this more perfect state,
with a few of its numerous applications, will form the subject
of this communication.
For experimental researches in electro-magnetism, it is ex-
tremely useful to have constantly at hand a quantity of copper
wire, of different degrees of fineness, coated with sealing-wax.
The most convenient mode of giving the wire this coating, is
the following : — Stretch the wire between two supports, heat
it gradually, from one end to the other, with an iron bar, or
spirit-lamp, and continue rubbing the heated part with a stick
of sealing-wax ; the wire will receive a fine coating, sufficient
to prevent metallic contact when portions of it are pressed
together in the construction of any piece of electro-magnetic
apparatus.
Take the wire thus coated, heat it slightly to prevent the
wax cracking, and form it into a rectangular shape, consisting
of six, eight, or ten repetitions of the wire, according to the
delicacy of the instrument required. The upper side of the
rectangle must then have the wires separated into two equal
portions, bent round a small cylinder, and then continued
straight, so as to leave a circular opening in the middle, about
one-third of an inch in diameter. The use of the circular open-
ing, in the upper side, is to allow a slender axis, carrying the
magnetic needles, to pass through it, in order to increase the
power of the instrument, and render the compound needle
30 Mr. Ritchie on a Torsion Galvanometer.
astatic. Portions of a brass tube, about an inch long, are to be
soldered to the ends of the wires forming the rectangle, for the
purpose of holding a small quantity of mercury, to render the
metallic contact complete. The annexed cuts exhibit a vertical
section of the rectangle, and a horizontal one of its upper side.
II
The wires, forming the rectangle, are pressed close together,
and secured by a waxed sewing-thread, rolled tightly round
them. The rectangle is then fixed in a rectangular box, having
the upper side formed of two sliding panes of window glass,
for the purpose of shutting up the needle from the agitation of
the air. Each pane has a small semicircle cut out of the middle
of the edge, by means of a round file, so as to leave a circular
opening directly above that in the rectangle. Various contri-
vances for suspending the magnetic needle might be adopted.
The following is perhaps the most convenient : — Into a strong
wooden sole, or base, fix two upright supports about three feet
long. A small stage at the top, having a divided circle on
its upper side, and which may be elevated or depressed at
pleasure, completes the frame of the instrument. The stage
has two holes of the same size as the supports, and at the
same distance, with two small screws passing through its sides,
opposite the centres of the openings, for the purpose of fixing
the stage securely at the proper height. A small cylindrical
wooden key or peg, having a small bore in the axis for the
purpose of receiving the end of the glass thread, passes through
the centre of the divided circle, and is made to turn easily,
without much friction.
After numerous trials, the following appears to me the best
mode of preparing the threads of glass, so as to have their
extremities somewhat thick and tapering, for the purpose of
securing them in the torsion key, and in the axis which carries
Mr. Ritchie on a Torsion Galvanometer. 31
the magnetic needles. Take a solid rod of glass, or a piece of
a clean thermometer tube, having a very fine bore, and draw
out one of its ends, as in the annexed cut.
Direct the very point of the flame on the thick portion at A,
and pull it out, between the two hands, to the proper length.
As it is hardly possible to get a thread of glass of the proper
length and fineness, at the first trial, it will be found necessary
to draw several, and select the one best adapted to the purpose.
Two slender darning needles, of the best steel, are then to be
selected, the eyes to be broken off, and the ends filed to a point
similar to the other ends, and then strongly magnetised in the
usual way. The needles are then to be fixed transversely in a
piece of straw, or other light substance, about an inch long, and
at the distance of about half an inch from each other, with their
corresponding poles in opposite directions — the one needle in-
tended to be above the upper side of the rectangle and the other
below it. One end of the glass thread is then to be securely fixed
in the end of the straw, or light axis, by means of strong cement
or sealing-wax, whilst the other extremity is fixed, in like man-
ner, in the centre of the torsion key. A single fibre of silk,
having a small weight attached to it, is fixed to the lower end
of the axis, and made to pass through a small hole near the
lower side of the rectangle, for the purpose of keeping the axis
carrying the needles, in the centre of the circular opening in
the coil. The upper needle has two pieces of fine straw, several
inches long, fixed on its ends, so that the slightest deflection
may be readily observed. The extremity of one of the straws
is made to oscillate between two upright pieces of glass, to
prevent the needle moving over an extensive arc, and thus
lengthen the time necessary to complete an observation. The
whole will be obvious from the simple inspection of the an-
nexed vertical section of the instrument, in which A B is the
rectangular coil of wire, NS, S' N', the magnetic needles; C^
the stage with the divided circle and torsion key, and G the
glass thread. If, instead of the glass thread, the needle be
32
Mr. Ritchie on a Torsion Galvanometer.
suspended by a single fibre of silk, the instrument becomes a
galvanoscope of extreme delicacy. The following experiment
affords a striking illustration of the extreme sensibility of the
instrument with this modification.
EXPERIMENT I.
File off a few grains from a piece of zinc and] copper by
means of a coarse file ; place two of these near each other in the
bottom of a clean watch glass ; bring the clean ends of two fine
copper wires, connected with the cups of the galvanometer, in
contact with them, and then drop over them a small quantity
of dilute acid, and the compound needle will be deflected several
degrees.
Mr. Ritchie on a Torsion Galvanometer. 33
The instrument by which I ascertained the existence of a
Voltaic current from this elementary battery, consisted of a
greater number of coils in the rectangle, and the needles were
light and strongly magnetised.
Having thus minutely described the torsion galvanometer,
I will now shew some of its applications ; but before doing
this it may be thought necessary to establish its accuracy, not
by reasoning (which is already done in the Philos. Trans.), but
by direct experiment. The following experiments will shew
in a striking manner the perfection of this instrument above
those formerly employed.
EXPERIMENT II.
Take two equal rectangular slips of copper and zinc, an
inch broad and eight or ten inches long, and divide them into
square inches by narrow bands of wax or cement. Solder
copper wires to their extremities, and fix them in a small frame,
so that they may always be placed at the same distance from
each other. Immerse them in a vessel of water, containing a
small quantity of sulphuric acid, to the first horizontal divi-
sion ; turn round the torsion key till the untwisting force of
the glass thread balances the deflecting power of the electric
current, and note the number of degrees of torsion. Immerse
them to the second division, turn round the torsion key as
before, and the degrees of torsion necessary to balance the
deflecting force of the current, from two square inches, will be
found double of those for one square inch. Repeat the experi-
ment with three, four, &c., square inches, and the degrees of
torsion will be found to be proportional to the surface of the
plates immersed.
Having thus shewn experimentally the accuracy of the
instrument, I shall now apply it to determine the power
gained by Dr. Wollaston's contrivance of a Galvanic battery
above those formerly in use.
EXPERIMENT III.
Having provided a clean slip of copper, two inches broad
and about four inches long, I formed it into a rectangle, open
VOL. I. OCT. 1830. »
34 Mr. Ritchie on a Torsion Galvanometer.
at the top, and then covered the inner surface of the bottom
with cement. A plate of zinc, of the same size with the
rectangle of copper, was placed exactly in the middle, hav*
ing a face of clean copper opposite each of the sides of zinc.
Copper wires being soldered to the rectangle of copper and
to the plate of zinc, and their ends dipped into the small
metallic cups of the galvanometer, the elementary battery was
then immersed in very dilute acid, and the torsion key turned
till the deflecting force of the battery was vanquished, the
number of degrees being about a thousand. Having removed
the battery, I covered one side of the plate of zinc and the
opposite surface of copper with cement, and repeated the expe-
riment as before ; when, as might naturally be expected, the
number of degrees of torsion were found to be very nearly five
hundred. We may, therefore, safely conclude that the double
plate of copper doubles the quantity of electricity without, of
course, altering its tension.
Immediately after (Ersted's beautiful discovery of the mu-
tual action of magnets and Voltaic conductors, it was known
that an immense increase of electro-magnetic power is gained
by diminishing the distance between the copper and zinc
plates ; but, for want of a proper galvanometer, the law does
not seem to have been determined with that rigorous accuracy
which places its truth beyond the possibility of doubt. To
accomplish this was the object of the following experiment.
EXPERIMENT IV.
In order to avoid every source of inaccuracy, I procured a
rectangular wooden box, about a foot long, two inches broad,
and two and a half inches deep, into which plates of zinc and
copper two inches square might be fixed at any distance from
each other. Having filled the box with dilute acid, I placed
the copper plate at one extremity and the zinc plate at the
distance of nine inches, and observed the degree of torsion, as
in the preceding experiments. I then untwisted the thread,
placed the zinc at the distance of one inch from the copper, and
observed the degrees of torsion, which were now nearly three
times as great as before, This was next repeated with the
Mr. Ritchie on a Torsion Galvanometer. 35
plates at the distance of nine and four inches, and gave the
deflecting forces in the ratio of 2 to 3, which are the square
roots of 9 and 4. After trying the effects of the plates at
different distances, the following law was established, which
had formerly been obtained by a different process : viz. — that
the quantity of Voltaic electricity circulating along the metallic
conductor connecting two plates of dissimilar metals, is inversely
as the square roots of the distances between the two plates.
This law was originally deduced by Professor Gumming, by
observing the deflection of a compass needle, and then taking
the deflecting forces as the tangents of the angles of deviation
from the original direction of the needle and straight conductor.
When I undertook this investigation, it had escaped my me-
mory that any law had been discovered which connected the
deflecting force with the distance of the plates. This circum-
stance, as well as the different process by which it was deduced,
affords the most complete proof of its truth.
This law is certainly very different from what we might
at first have expected. We might, without experiment,
have argued thus: If one inch of fluid between the plates offer
a certain resistance to the electric current, two inches will pre-
sent twice the resistance, three inches three times the resist-
ance, 8fc. &c. With regard to the cause of this curious law,
we can at present scarcely offer a conjecture. Does the electric
fluid, after passing through a certain length of an imperfect
conductor, acquire some power which enables it to pass more
easily through an equal portion ? There are phenomena in
nature in which imponderable agents do acquire such proper-*
ties, Light may be so far modified as to pass entirely through
glass, which, without such a modification, would have been
partly reflected. De Laroche discovered that invisible radiant
heat, after passing through a thin plate of glass, passes with
less resistance or loss through a second, &c. But, instead of
being led away by analogies, which by some may be regarded
as fanciful, I shall mention one practical lesson to be deduced
from the law in question. In constructing a battery for electro-
magnetic purposes, there is not so much power gained as might
be supposed by putting the plates very near each other. For
example, if the plates are at the distance of a quarter of an
D 2
36 Mr. Ritchie on a Torsion Galvanometer.
inch, and then at the distance of one-eighth of an inch, the
power gained will only be as the square root of .25 to the
square root of .125, or nearly as 50 to 35 ; and the hydrogen
constantly escaping, and partially occupying the place of the
liquid in the narrow cell, considerably diminishes this apparent
increase of power. This circumstance ought not to escape the
attention of philosophical instrument-makers in the construc-
tion of batteries for electro-magnetic purposes.
Considerable uncertainty still prevails with regard to the law
which connects the conducting powers of metallic wires with
their lengths. According to Professors Barlow and Gumming,
the law is the same as that established for fluid conductors.
According to the experiments of M. Becquerel, the conduct-
ing powers of metallic wires are simply as their lengths. The
following experiment will set the question at rest.
EXPERIMENT V.
The galvanometer I have hitherto used requires the following
modification for this investigation. Form the rectangle of a
single copper wire, and suspend the magnetic needle directly
over it, and in the same direction. Take a certain length of
the same copper wire, and connect it with a small elementary
battery, turn the key, and observe the degree of torsion. Take
nine times the length of the same wire, and repeat the experi-
ment with the same battery and acid, and the number and
degrees of torsion will only be one-third of those obtained in
the first experiment. This experiment I repeated with dif-
ferent lengths of bell- wire, and always found that the intensity
of the current was inversely as the square roots of the lengths
— the same as the law for liquid imperfect conductors.
M. Becquerel seems to have fallen into the mistake we have
now pointed out, by using a galvanometer made of a long wire
formed into a coil, and neglecting the resistance the electric
current must have experienced in passing through the instru-
ment itself.
The conducting powers of metallic wires, or their ribands,
for common electricity, depends almost entirely on their surface,
without any reference to their thickness. The fact would seem
to be, that common electricity glides along the surface of the
Mr. Ritchie on a Torsion Galvanometer. 37
metal, being prevented from escaping by the pressure of the am-
bient air, whereas Voltaic electricity requires a certain thickness
of metal for its transmission*. Voltaic electricity, from a single
pair of plates, seems to be conducted from molecule to molecule,
in some measure resembling the conduction of caloric. Hence,
if the diameter of the wire be too fine to allow of this depth of
metal, a considerable portion of the electric fluid will be stopped.
But, provided the wires be sufficiently thick to allow of this
necessary depth of the electric film, then the conducting power
ought to be nearly as the circumference of the wire, or as its
diameter. If one of the wires be very fine, and the other of a
large diameter, this law could not exist. This fact was clearly
proved by the following experiment.
EXPERIMENT VI.
Having taken equal lengths of very fine copper wire and of
common bell wire, I used them successively as conductors from
the same elementary battery, and ascertained the degrees of
torsion as in the former experiments, and found that the large
wire conducted better than in the mere ratio of the diameters.
For example, the diameter of the one wire was scarcely three
times that of the smaller, yet the ratio of their conducting
powers was nearly as one to four. I then passed the thick wire
through rollers, till it was reduced to a very thin riband, hav-
ing its external surface nearly twice that of the original wire,
but instead of conducting double the quantity of the original
wire, it conducted only three-fourths of that quantity f.
From the law established in the fourth Experiment, we need
scarcely despair of seeing the Electro-Magnetic Telegraph
established for regular communication from one town to another,
at a great distance. With a small battery, consisting of two
plates an inch square, we can deflect finely-suspended needles
* Hence if a metallic rod be raised to a red heat, its power of conducting com-
mon electricity is increased, whilst its conducting power for Voltaic electricity is con-
siderably diminished.
f The fact here established bears a striking analogy to a curious fact discovered
by Mr. Barlow. He found that it requires a certain thickness of iron or steel to
receive the magnetic influence — Is there any relation between the thickness of
the iron or steel necessary to receive the magnetic influence and the thickness of
the conductor necessary to convey that kind of electricity which acts most power-
fully on the needle ? "
38 Mr. Ritchie on a Torsion Galvanometer.
at the distance of several hundred feet, and consequently a
battery of moderate power would act on needles at the distance
of a milej and a battery of ten times the power would deflect
needles with the same force, at the distance of a hundred miles,
and one of twenty times the force, at the distance of four hun-
dred miles, provided the law we have established for distances
of seventy or eighty feet hold equally with all distances what-
ever.
PRACTICAL AND PHILOSOPHICAL OBSERVATIONS ON
NATURAL WATERS.
BY WILLIAM WEST, ESQ.
§ 1. On the Water from Peat Lands, and its application to
domestic purposes.
T HAD an opportunity, some time since, of closely examining
many specimens of water from this part of the country,
(Leeds,) which were soft and nearly pure, containing from
half a grain to two grains of solid matter in the gallon, one
part in 50 or 60,000, but tinged by colouring matter from
peat. With most of the re-agents no action took place, or it
was so slight as to be difficult of detection ; but when evapo-
rated until a gallon was reduced to a few spoonfuls, the com-
position of this small portion was easily shewn to be sufficiently
complicated : and it varied greatly in different specimens which,
passing in their original state under the action of the tests with-
out any alteration being produced, might have been supposed
exactly similar. The fact is, the water precipitated from the
rain and mountain mists had taken up small portions of the
soluble substances which came in its way ; but its course had
been too short, and its action too much confined to the earth's
surface, to acquire much from any of these. These streams
were on high moor land; either running in the ravines, or
springing from natural or artificial openings in mill-stone
grit.
One practical difficulty of considerable importance arises
when water from brooks in such situations is employed, or
Mr. West on Natural Waters. 39
when a large quantity of such water has to be collected for the
supply of a town. The upland streams, deriving their supply
from high and barren land, barren of all but moss and heather,
are more or less deeply coloured by vegetable matter derived
from peat. There has occasionally been much controversy
respecting this peaty water; and among those who have en-
tered keenly into this, both parties have been, I think, some-
what in the wrong. While those are mistaken who condemn,
in the gross and for every purpose, water tinged in any degree
with peat, or who maintain that it cannot be deprived of this
colour, they are equally so who treat such an impregnation as
not injurious to any of the useful qualities of the water. What
may be the exact effect on the human constitution of the small
quantity of soluble vegetable matter, of whatever nature, from
which the hill streams derive their colour, I do not pretend to
say ; but the water is unsightly, not only from the brown
tinge, but from the coloured froth formed by the bubbles of
air which escape on standing. These, in water in general,
break as they reach the surface ; but, from the viscidity
produced by the peat, they collect and remain, giving an un-
pleasant and repulsive appearance.
Now, I hold an opinion, which has been confirmed by some
experienced medical men, that the salubrity of water, as a beve-
rage, depends less upon its absolute purity than upon its being
brisk and palatable. We know how palling to the stomach is
water which has been boiled and cooled, or has stood long in
open vessels ; yet, so far as the term * pure water' means water
free from the presence of other substances than water, such is
frequently more pure than when originally drawn. I appre-
hend, that though much in diet which is agreeable to the palate
is at the same time unwholesome, yet that will not commonly
perform its part well which is itself positively disagreeable.
Again, in experimenting upon this peaty colour, either as
strong as it could be obtained, or in its common and more
dilute state, I found it closely to follow the habits of those
vegetable infusions which are prepared expressly for the colour
they impart. Thus it is found dissolved, not merely suspended,
passing any number of times through filtering-paper without
40 Mr. West on Natural Waters.
diminution, and not much impairing the transparency or re-
fractive power of the water. It is quickly and completely
separated by aluminous earth in a state of minute division;
the alumine, at first snow-white, becoming brown, and forming
a true lake. It is separated by muriate of tin, in flakes com-
posed of colouring matter and oxide of tin. Many other of its
habitudes agree — all, indeed, which I have compared. Thus
it more readily leaves the water> and fixes itself on the material
boiled or washed in it, when that is of silk or woollen, animal
productions — than when linen or cotton, vegetable fabrics.
Printed cotton, however, of bright colours, is at once stained
and altered, from the mordant of the print combining with or
fixing the additional colour. White linen or calico, on the
other hand, once washed in pale yellow water, is not percep-
tibly stained ; with deep brown water it is discoloured by the
first operation ; and the same result takes place from the re-
peated use of that which, in a single trial, produces no sensible
effect.
Though this substance obstinately resists mere filtering, such
as would separate suspended impurities, yet sand, containing,
as I apprehend, some alumine, is effectual in separating it:
but the kind of sand which will filter at once most speedily
and effectually ; the degree of mixture with clay which will
produce the greatest chemical effect without lessening mate-
rially the permeability of the sand ; the depth of sand required ;
the fall or pressure which best unites speed and effect; — all
these are points calling for experiment, and which, if not well
ascertained before attempting to filter on the great scale, may
cause much useless delay and expenditure. Long exposure in
reservoirs to light and air, assisted, as I believe, by the action
of the clay with which they are lined, destroys the colour.
The water with which one large town is supplied enters the
reservoirs more deeply stained than any of the streams which
formed the subject of my experiments ; and left them, at the
time it was brought to me, less coloured than the water of the
river Aire. But I am told that, in winter time, when a flood
happens, the water from the surface, leaving each reservoir
soon after it enters, is delivered from the pipes to the houses
Mr. West on Natural Waters. 41
very much discoloured. Where such water, then, must be
used, (and from its softness it has many advantages,) a well-
arranged and well-managed filter is highly desirable.
It may serve to shew how cautious we should be in attri-
buting mistakes on scientific points to any writer, from minute
criticism of the terms used, to notice that, in an official report
from one of the most eminent chemists of the present day, it
is stated that the yellow or light-brown peaty water is not, in
his opinion, objectionable for * any domestic purpose.' He
undoubtedly used the term in a limited sense, confining it to
the preparation of food, and to its power as a simple detergent,
without taking notice of the probability of its leaving a colour
of its own. Again, the Commissioners of 1825, on the Supply
of Water to the Metropolis, in their able report, say, « It must,
however, be recollected, that insects and suspended impurities
only are removed by filtration ; and that, whatever substances
may be employed in the construction of filtering-beds, the
purity of the water, as dependent upon matter held in a state
of solution, cannot be improved by any practicable modification
of the process/ &c. &c. Now this, as I have proved by expe-
riment, is not applicable to some dissolved animal and vegetable
matters : it can only be strictly true as applied to the salts con-
tained in water ; and though undoubtedly correct in the general
as to these, yet exceptions are still possible.
Besides the superiority of filtering over mere subsidence, for
the mechanical separation of impurities, I think enough atten-
tion has not been paid to the power of alumine to separate both
animal and vegetable matter, however perfectly dissolved. I
evaporated deep-coloured peaty water, previously filtered and
very bright, and obtained at the rate of 1.6 grains from one
pint. On calcination, these 1.6 grains were reduced to 0.6.
About 0.8 grains of the quantity thus dissipated was vegetable
matter ; 0.2 or upwards was carbonic acid, from carbonate of
lime. I then separated the colouring matter by well-washed
alumine ; the water was left perfectly limpid : on evaporation
it left one grain, which, on calcination, became 0.6, as before :
allowing for the carbonate of lime decomposed by the heat,
not less than four-fifths of the vegetable matter had separated
in combination with alumine.
42 Mr. West on Natural Waters.
I exposed a weak solution of gelatine to similar treatment,
with correspondent results : the greater part was separated in
the same manner ; the water evaporated left little but the salts
contained in the jelly. I ascertained that common clay pro-
duced, by allowing longer time, the same changes in appear-
ance, and that the weight of the dissolved matter was less than
before ; but I could not easily free the clay so entirely from
salts as to bring the proportion separated to the same degree
of certainty by weighing.
§ 2. On the deposition of Sulphate of Lime from Hard
Waters, and on the Solvent Power of Hard Waters.
Sulphate of lime, being held in waters by its own solubility,
cannot be wholly separated by mere boiling : on applying heat
to its solution, one of two effects takes place : if the evaporation
is slow, the solution is left more concentrated and stronger ; if
it be boiled briskly, the solution may remain of the same strength
though not saturated, while a portion of the sulphate separates
in a solid form. The manner in which this proceeds is curious ;
the property is common in a greater or less degree to all sub-
stances difficultly soluble, though lime itself is the most strik-
ing instance. When a bubble of steam arises, the salt which
was dissolved in that portion now vaporized, separates in the
solid state ; and as such bodies require not only a large portion
of water, but a long time to effect solution, before this is again
dissolved, many other particles are separated, and thus the
quantity deposited goes on increasing, the strength of the so-
lution itself remaining all the time nearly the same, though any
difference which may take place is of course in the way of
increase.
Thus in the production of ' fur,1 in the vessels in which it is
boiled, the sulphate of lime acts about as speedily as the car-
bonate, and probably more injuriously. In many operations,
therefore, it becomes a very serious evil. I was assured at
Manchester that it was necessary frequently to empty the engine
boilers, and chip out the crust formed, in some cases as often as
once in six weeks ; the labour of effecting this, and the hin-
Mr, West on Natural Waters. 43
derance to work, and loss of fuel consequent on letting out the
fire, are not the only disadvantages attendant upon the cir-
cumstance. The boilers must be more quickly destroyed,
from the great heat of the outside being very slowly conducted
through the earthy crust. In fact, they told me that for a
short time before the usual periods for cleaning, it was difficult
to get the steam up, whatever firing was used. Nor is the
employment of the Sabbath for this purpose to be left out of
the question. The adhesion of the earthy matter to the iron
is lessened, and the interval between the cleanings consequently
protracted, by the use of potatoes, the pulp of which envelop-
ing the crystals, lessens their tendency to cohere, and preserves
them for a time suspended in the water of the boiler.
I have taken much pains with a set of experiments to settle
this point, among others, viz., * On the comparative solvent
powers of waters holding in solution various salts in different
proportions.' I have come to the conclusion, that the earthy
salts exert a great influence in preventing the solvent action of
water on vegetable substances ; the proportion dissolved by
pure or soft water being considerably greater than that by hard
water. Portions of tea of the same weight, viz., thirty-six
grains after drying, with equal quantities of boiling water of
different kinds, standing in similar vessels for the same time,
yielded, the hard water, after deducting the weight of the
earthy matter, about four grains of extract ; that is, the infu-
sion left, besides the earths, four grains, on evaporation to
dryness; the leaves again dried weighed thirty-two grains:
the extract from the soft, or distilled water was pretty exactly
eight grains; the leaves, after drying, twenty-eight grains.
Thus, the soft water had extracted from the tea just twice as
much as the hard. I made numerous experiments of the same
description, but found it difficult, from circumstances con*
nected with the absorbent nature of the leaves, to obtain
exactly the same quantities of extract and of spent leaves, in
repetitions of the same experiment, and cannot, therefore, de-
pend on this mode of comparing waters differing little from
each other ; and the effect of pure water is certainly very near
to that of any natural water containing carbonate of soda. I
think, however, that the soda does a little increase the quantity
44 Mr. West on Natural Waters.
taken up, and that it is probable the celebrity of these waters
for such purposes depends on three circumstances, — the real
increase of solvent power ; the darker colour, giving the ap-
pearance of greater strength ; and the sensibility of the palate
being increased by the soda.
§ 3. On the Gaseous Contents of Waters.
The gases usually found in such waters as are commonly em-
ployed for other than medicinal purposes are, carbonic acid
gas, azote or nitrogen and oxygen.
In the waters containing soda, there are commonly small por-
tions of sulphuretted hydrogen and of carburetted hydrogen, but
these soon escape on exposure to the atmosphere, leaving the
water free from its original unpleasant smell. Oxygen gas is
less frequent and less abundant than might be supposed. In
many cases I have proved its absence, by introducing into the
water substances which readily absorb oxygen, by exposing to
such substances the gas separated by boiling, and by exploding
a mixture of the gas with a known quantity of oxygen, and
more than its equivalent of hydrogen. This absence of oxygen
is easily accounted for, where substances exist which would at
once combine with it, as oxide of iron, or sulphuretted alkalies ;
but I have had the same results in cases where it might have
existed without interfering with the constituents of the water.
From its absence under these circumstances, as well as upon
other grounds, we may infer that the gases disengaged from
spring water are not absorbed from the atmosphere, but are
formed and taken up by the water while in the earth. Stand-
ing water and streams, however, undoubtedly absorb air. Dr
Ure states, that he obtained from such waters about l-35th of
their bulk of gases, of which from l-20th to l-10th was car-
bonic acid, and the remainder common air. He does not, how-
ever, say whether he tried any experiments to ascertain this
last point, or only assumed it to be so. I have invariably
found less oxygen, in proportion to the nitrogen, than in air,
and from . the principles which determine the absorption of
gases by water, it should be so. I have also always obtained
Mr. West on Natural Waters. 45
a greater portion of carbonic acid, as well as a greater volume
of the mixed gases.
From hard, brisk pump water I obtained, by boiling, quanti-
ties which, in round numbers, and for the specific gravity, varied
but little, in repeated trials, from sixteen cubic inches of car-
bonic acid, and the same quantity of a mixture of azote with a
small quantity of oxygen.
The water of the Aire, taken from the cut which supplies
the waterworks, gave two inches and three-quarters of carbonic
acid, and eleven inches and three-quarters of azote and oxygen,
the total quantity of gases being less than half that from pump
water. From that of a large fish-pond I obtained more gas
than from the river, but less carbonic acid, viz., two cubic
inches and a quarter of carbonic acid, fourteen inches azote,
and two oxygen.
It is only within these very few years that carburetted hy-
drogen has been recognised in water. Its presence was first
noticed, I believe, by Dr. Scudamore and Mr. Garden, inHar-
rogate sulphur-water. It is found accompanying sulphuretted
hydrogen in every water which I have tried in which that gas
occurs, and is disengaged from many springs in much greater
quantity than the water can absorb, so as to form large bubbles.
This phenomenon has been observed in many parts of the
world, and the inflammability of the gas disengaged in such
situations had been often noticed, but its exact nature has been
in most cases rather inferred than proved.
This circumstance of an inflammable gas, great part of which
is carburetted hydrogen, issuing spontaneously from water,
may be seen in several places in our neighbourhood. At Har-
rogate large bubbles occasionally rise through the water. At
Stanley there is a continual flow of small bubbles ; the dif-
ference depends upon the figure of the well or boring, and
that of the passages through which it is supplied. At Slaith-
waite the disengagement of gas is still more abundant, so that
there is a succession of large bubbles, and the gas may easily
be collected in considerable quantities, or set fire to at the
surface of the water.
The nature and amount of gaseous impregnation, though
often of moment in medicinal waters, is almost immaterial for
46 Mr. West on Natural Waters.
domestic purposes, with the single exception of water used
unmixed as a beverage. The gases do not appear to interfere
with the solvent properties of water, at least while cold, and
when heated they are quickly disengaged.
The changes which take place as to the gases, when brisk
pump water is exposed in open vessels, are rather curious. I
found that water yielding twenty-six cubic inches, viz., ten
carbonic acid, and sixteen azote, &c., when fresh drawn, gave,
after standing five hours, twenty-five inches ; the diminution
was in the azote, the carbonic acid remaining the same. At
the end of nine hours, the total gases, twenty-two inches, one-
fourth of the azote had escaped, but very little, not two per
cent., of the carbonic acid. After three days, however, the
case was different ; no further escape of azote had taken place,
the water yielded about fifteen inches per gallon, and of this
only from one and a half to two consisted of carbonic acid.
The quantity of this gas was smaller than in river or pond
water. If these experiments, which I have not had time to
repeat, are tolerably correct, they would shew that, on expo-
sure to the atmosphere, the azote and oxygen contained in
water very soon begin to separate from it ; that after a time
the carbonic acid partially escapes, the other gases remaining ;
and that this continues until very little carbonic acid is left.
The power of water to retain gases in solution depends, the
temperature and pressure remaining the same, on the affinity
of water for the gas, and upon the proportion of that gas in
the superincumbent atmosphere. Those having a great affinity
for water fly off in some degree when the gases above the
water are wholly different, and those least readily absorbed are
retained under an atmosphere of the same gas. Now, these
two are antagonist principles in the case before us, azote having
little affinity for water, but constituting four-fifths of the sur-
rounding common air ; carbonic acid being much more abun-
dantly absorbed, but having no atmosphere of its own desscip-
tion to press on the water containing it. No calculation could
enable us, I think, to ascertain beforehand the order and the
degree in which these effects would take place ; that is, to pre-
dict the result of these experiments.
GENERAL REMARKS ON THE WEATHER IN MADAGASCAR,
ANp CHIEFLY AT ITS CAPITAL, TANANARJVOU,
From the 27th of June, 1828, till the 1st of January, 1829; with a Meteorological
Journal from the 1st of January to the 25th of March, 1829.
BY ROBERT LYALL, ESQ.
British Resident-Agent, Member of many Foreign and British
Societies, &c., &c.
[Communicated by Mr. J. F. DANIELL.]
TVTE arrived at Tamatave on the 27th June, 1828. During
* our residence there till the llth of July, and of four days
at Ivondrou, the weather was very warm, and much resembled
that we had experienced at Mauritius before our departure.
On the journey to Tananarivou, it continued very warm, even
during the passage of the great forest, and until we crossed the
river Mangoor : it then became gradually cooler ; and, as it
was cloudy and windy on traversing the mountain called
Augave, (the height of which, above the level of the sea, may
be five thousand feet,) it was even cold. Indeed, the change
of climate was very remarkable ; and the weather continued
cold, not only on the road to the capital, but after our arrival
in it.
I entered Tananarivou on the 31st of August, on a beau-
tiful morning, with a splendid sun. The weather conti-
nued very fine, and in the middle part of each day it was
warm for a considerable period ; but, as there was no rain, the
mountains had a very barren and bleak appearance. East and
south-east winds blew hard, almost every evening, and ren-
dered it so cold, that, in slender houses, we were necessitated
to have recourse to woollen clothes, to a small fire both morning
and evening, and to blankets in the night. Excepting a few
days, on which it was warm, (as the 12th of August, when his
late majesty, Radarna, was interred, and a few hours before
and after mid-day,) the thermometer ranged from 50° to 60°
of Fahrenheit for a considerable time. On the 17th of August
it was windy, and so cold, that we put on our cloaks to go to
church. The sympiesometer and the barometer were very little
affected, and the medium altitude of the latter may be reckoned
48 Mr. Lyall on the Weather in Madagascar.
25.32 inches. We had neither rain, nor storms, nor even any
high winds.
The weather, about the end of August, became consi-
derably warmer, and continued fine ; the evenings and the
mornings were beautiful and highly salubrious, being clear, dry,
and cool. Afterwards the thermometrical range became higher,
the temperature being generally between 60° and 70° Fahren-
heit : now and then, however, for a few hours after the middle
of the day, it rose as high as 75° and 80°. Again, when the
heat had been less intense in the day, it descended in the
evening to 65° and 60° of Fahrenheit. The sympiesometer
and the barometer seemed nearly stationary during September
and October ; and the wind was regular, at least every even-
ing, and blew from the east and south-east. From about the
beginning to the 22nd of November we had, now and then, a
heavy shower, but no great quantity of rain fell ; so that the
Malagash government and people began to fear the loss of
their rice crops, in consequence of long-continued drought.
They had recourse to their idols, or god?, for assistance, as
recorded in my journal of this period. On the afternoon of
the 22nd, however, ' a day sooner than the gods predicted,'
rain fell very copiously, and continued to do so all night, and
even during a part of the 23rd. This date (though afterwards
we had some fine days) may be reckoned the commencement of
the rainy season in 1828. This remarkable epoch has therefore
been late ; but I have been told that it has occurred, though
very rarely, that the rainy season has not commenced till
January, which must always be a serious misfortune. It has
been remarked, that the periodical rain has not followed the
usual course — of falling in heavy showers, some time between
the hours of two and six o'clock, P. M. On the contrary, it
has frequently commenced earlier, and, more frequently, at a
later hour ; indeed, it has sometimes rained the whole night,
and even in the morning and forenoon we have had heavy
showers. Again, after heavy rain-falls, there have been pe-
riods of one day, of two days, and even of three days, very
fine weather, and without a drop of rain ; but with such heavy
dews during the night, as, in the morning, led me to suppose
that it had rained. Thunder-showers, which have been fre-
Mr. Lyall on the Weather in Madagascar. 49
quent, have generally fallen in the afternoon. The lightning
was vivid, and the thunder loud and near, so that a number of
lives were lost by the former, in the capital and in its vicinity.
Very often in the evening, and especially after thunder-storms,
as in Russia, a great part, and even nearly the whole of the
hemisphere was illuminated by that kind of lightning (called
zara by the Russians) which flashes from cloud to cloud, but
never approaches the earth, and by which lives, I believe, are
never lost.
About the end of November, or the beginning of December,
at four o'clock, p. M., a very heavy shower, mixed with large
hail, fell, to the astonishment of Mr. Chenard, the tutor of my
children, who had often heard of, but had never seen such a
* phenomenon.'
Ever since the rainy season has set in, with the exception of
a few hours before and especially after noon, the heat has been
very moderate. The barometer, comparatively speaking, has
varied little ; nor has the sympiesometer been greatly affected
by the changes of weather. The wind, since the 22nd of No-
vember, has been more variable, and frequently from the north,
north-west, and west.
The quantity of rain which fell previous to the 22nd of
November may be estimated at two inches, and that since the
22nd of November at about twelve inches — total, fourteen
inches — till the commencement of the report for the month of
January, 1829, which accompanies these observations.
JOURNAL
VOL. I. OCT. 1830. E
50 JOURNAL of the WEATHER, at TANANARIVOU, Capital of
e
8
S3
Jan-
uary.
Baro-
meter.
Thermometer.
Hygrometer.
Rain.
WIND.
Max.
Min.
Dew Pt.
Direction. Force.
1 25 -25
75
66
75
68
•g
E Gentle
2
25-25
78
67
74
87
.
K & NW Do.
3
25 -30
77
70
74
66
•
NW Do.
4
25-28
79
69
76
65
•M
NW & W Strong
•
5
25-28
74
66
74
68
.
E Moderate
6
25-27
74
62
70
68
•65
ENE N Si NW Strong
7
25-32
74
64
70
<;s
•28
E & NE Gentle
8
25-28
74
66
68
68
•1
NW
Do.
9
25-24
76
68
69
66
NW & W
Do.
10
25-25
76
67
68
65
1-5
Ibid.
Do.
11
25-28
74
66
69
64
•58
NW&W
Gentle with breezes
c
12
25-28
75
66
69
67
•80
NWW&E
Calm with breezes
13
26-22
79
65
68
65
•45
E and calm
Do.
14
25-24
74
65
68
68
•48
Calm, E and calm
Gentle
15
25 30
73
64
66
64
•10
Calm,EESE& E
Gentle with breezes
16
25'25
73
65
66
64
• •
Calm, & E & SE
Do.
17
25-34
73
65
66
63
-
Calm & E
Do.
18
25-33
73-5
65
66
63
1'07'
Calm, E NNE & E
Calm and gentle
with breezes
19
25-32
73-5
66
67-5
64
•27
ENE & calm
Gentle
0
20
25-31
72-5
65
67
66
•60
E calm & SW
Do.
21
25-28
73
62
63
64
3-20
ENEE&SW
& calm
Gentle with breezes
22
25-30
73
62
65
65
1-0
E &SW
Breezes and squally
23
25-31
73
62
67
65
•76
NNE & E & SW
Squally
24
25-29
74
63
69
66
•56
NE &E
Calm and breezes
25
25-24
75
62
67
65
•1
NE W & NW
Do.
26
25-22
74
64
66
64
1-45
NE NNE & calm
Gentle with breezes
27
25-26
75
65
67
64
•8
SE &E
'Do.
1
28
25 -30
72
65
66
64
•15
SE &E
Do.
29
25-28
73-6
64
66
64
.
E&SE
Gentle
30
25-26
72-4
64
66
65
•11
NE E & SE
Do. with breezes
31
25-28
73
64-5
66
67
'I
Do.
Do.
MADAGASCAR, for the Month of JANUARY, 1829.
51
GENERAL OBSERVATIONS ON THE WEATHER, &c.
Weather cloudy.
Weather clearer.
Weather cloudy.
Wind in the evening, west and strong.
Heavy showers, with thunder and lightning.
feather cloudy j during the last 18 hours, the wind went nearly round the compass ; heavy showers.
Feather clear. Sunshine with gentle showers. Unsettled appearance.
/eather in the morning clear, and till noon, with strong breezes. Trifling showers. Heavy dew in
the night. Fog this morning.
Weather clear. Heavy dew in the night.
I Weather clear till 3, then cloudy. Excessively heavy rain in the evening, when the bar,
and there was a corresponding fall of the sytnp. Much thunder and lightning.
•. sunk to 26° 18''
Weather clear till about 2 P.M., then overcast. In the afternoon rain fell amidst a fog. A good deal
of thunder and lightning.
f Sympiesometer, 27*72.
Weather cloudy, especially after 2. Thunder and lightning, P.M. . -| Temperature, 74'6.
(.Barometer, 25 '23.
After 2 weather became cloudy. About 5 P.M., partial rainbow In the south-east. Moon obscure in
the evening. Constant gentle rain, with heavy showers in the night.
Weather cloudy, with clear intervals. Fine day. Rainbow as yesterday. Rain began at 2 P.M. Heavy
showers. Moonlight and starlight evening, with clouds here and there. No rain in the night. Cloudy
and calm this morning.
Clear intervals and showers. Moon Very hazy. Evening darkish. Some thunder and lightning with
showers, and fair intervals.
Symp. and bar. kept rising all day. In the evening, symp. 27'98. Temp. 65. A uroraborealis in the even-
Ing. Moonlight and many constellations visible till 10 P.M., when the whole heavens became obscure ;
yet, as was to be expected, no rain fell ; but there was a strong squall. Morning cloudy.
Beautiful day. Symp. and bar. fell a little after mid-day. Clear moonlight and starlight evening, and
many planets and constellations beautifully seen ; but at half past 9, not a single star was visible.
Morningtine. Mid-daysultry and cloudy. At 1 P.M., symp. and bar. falling; at 2 weather overcast; at4,
symp. 27'83 ; temp. 71 ; bar. 25-83, when there was a heavy shower with thunder. Weather now fair.
Weather cloudy in the morning. Fine from 9 in the morning till 2 P. M. ; then overcast. Symp. fell
to 27'94, and bar. to 2u'8 ; heavy shower at 3, then fair weather, alternatefy with thunder and
showers. Sheet lightning in the evening.
Weather cloudy and sultry ; at mid-day dew point 66 (black ball,) temp. 73. Fall of symp. and bar,
trifling; though there were heavy showers. Morning foggy.
Weather cloudy ; then clear with sunshine and sultry. At 1 P.M., symp. 27 78, temp. 72'6, bar. 25'26,
dew point 62. Heavy showers at 1, 3, and 5 P.M. Rained all night. Now fair with sunshine.
Weather cloudy, then fine, and again cloudy. After half past 1 rain began. Very heavy showers In
the afternoon, evening, and night, with fog. Now foggy.
Weather cloudy, then fine, afterwards overcast, and rain commenced before noon. Thunder in the
afternoon with squalls and heavy showers. One remarka
trifling. When the wind was at s.w. there were squalls.
afternoon with squalls and heavy showers. One remarkable heavy shower. Fall of symp. and bar.
" i the '
Weather cloudy, then tine till near noon, when rain commenced. Heavy showers with thunder. Very
uai -in, sultry, and oppressive at 2, and afterwards.
Weather ve
to sink at
breezy, and even squally in the afternoon. " Much thunder. Appearance of a" surrounding storm.
Conjecture that rain fell at a distance,
jry tine from 9 A.M. til!2 P.M. ; then cloudy, and a trifling shower fell. Symp! and bar. began
1 1, and though the day was still very fine, they sunk till 2, when a trifling shower fell. Sultry,
Though neither symp. nor bar. rose, weather very fine from 6 A.M. till 1 F.M. , then cloTidy and sultry.
Much thunder in all directions, and continued heavy rain with breezes.
Fine weather, though cloudy and sultry. Symp. and bar. nearly stationary all day; a little rain.
Symp. and bar, ascended in the evening. Aurora borealis in the evening.
Weather cloudy, sultry and fine. No rain during day. Symp. and bar. rose in the evening. A heavy
shower between 5 and (> this morning. Now cloudy.
Fine weather toward 4 P.M., symp. fell to 1V76, and bar. to 25 26, but they soon rose again. No rain.
Magnificent starlight evening.
Fine weather. Symp. and bar. fell a little in the evening. Heavy shower at 11 last night. Now
cloudy, but with indication of fair weather.
Beautiful weather. Last twenty-four hours, symp. and bar. varied very little. At 6 this morning a
trifling shower.
52 JOURNAL of the WEATHER at TANANARIVOU, Capital of
a
Feb-
ruary.
Baro-
meter.
Thermometer.
Hygrometer.
Rain.
WIND.
Max.
Min.
Dew Pt.
Direction.
Force.
1
25-31
72
62-3
65
64
•9
E&SE
Grentle with breezes
2
25-29
72
63 -2
65
64
.
Do.
Do.
1
25-29
73
64
67
67
.
ENE&E
Do.
4
25.29
73'4
61-2
61
57
• •
E
Gentle
5
25-28
76-2
66'3
68-5
66
• •
Do.
Do.
•
9
25-30
73-5
67-5
67
66
•
E& SE
Do.
7
25-25
76-6
68-3
69
67
•3
Do.
Do.
8
25-22
75-3
64
64-5
61
•
E
Gentle with breezes
9
25-20
74-5
65-2
61
63
• •
E & E by S
Do.
([
10
25-18
77-2
(50-3
61
54
E
Gentle during day,
strong in the night.
11
25-12
76-4
66-8.
67
64
• •
ESE &S
Gentle with breezes
12
25'6
76-2
68-5
68
67
•22
SE & NNW
Gentle and then
strong
13
25-21
75-8
67-4
68-6
67
•36
NNW & NW
Strong with squalls
14
25-28
79-3
67-3
67
65
•4
NW N & NE
Gentle
15
25-34
73-2
66
67
65
•20
E & calm
Do.
16
25-35
72-7
05-5
6S-5
64-50
•1
SE E & NE
Very gentle
17
25-34
73-8
62-5
64-65
62
•1
E.E by S&E
Moderate
0
18
25-33
73-6
62 -S
64
61
•
E
Strong with breezes
19
25-36
73-7
62-7
63-5
61
•
E
Moderate with
breezes
20
25-37
73-2
61-8
64
57
.
ESE
Do.
21
25-35
71-4
60-2
64
61
.
Do.
Do.
22
25 '37
72-6
60-2
64
63'5
•1
Do.
Strong with breezes
23
25-34
74-1
58-4
63
61
.
Do.
Do.
24
25-34
73-5
61-3
65
60
•1
SE
Do.
25
25-34
70-6
61-4
64
60
•
ESE
Do.
T
2rt
26'86
69-8
60-2
63
59
•7
ESE SE & ENK
Do.
27
25-34 6ST>
57-3
63
60
.
E &ENE
Do.
28
25'32 69 -4
57
62
58
•1
ENE
Do.
MADAGASCAR, for the Month of FEBRUARY, 1829. 53
GENERAL OBSERVATIONS ON THE WEATHER, &c.
Weather cloudy. Sympiesometer and barometer nearly stationary. Gentle shower one P.M. Even-
ing cloudy. Morning cloudy.
Weather cloudy. Symp. and bar. fell a little In the forenoon, but ascended again in the afternoon.
Weather fine, but sultry. Symp. and bar. nearly stationary. Sheet lightning in the evening.
Weather very line. Symp. and bar. still nearly stationary. Star-light evening, with much sheet
lightning. Beautiful fresh morning.
Beautiful weather ; yet after two o'clock P.M. the bar. fell to 25.25, and the symp. also sunk. Even-
ing line. Much sheet lightning in the evening. A great deal of distant thunder. Conjecture
that rain fell at a distance.
Fine weather. Beautiful evening. At half-past ten o'clock, when taking an observation of Castor,
the whole heavens became covered by clouds. Much sheet lightning in the evening. Fine morning.
Fine weather: toward 3 P.M. symp. arid bar. fell, and still they remain low. A trifling shower at
half post 9 in the evening. Some sheet lightning in the evening. Cloudy morning.
Fine weather. Symp. and bar. rose a little after seven P.M. ; but fell again in the night. Sheet
lightning in the evening. Fog between five and six o'clock this morning. Heavy dew.
Soon after mid-day, symp. and bar. fell to their present state, though the weather was, and still is
beautiful. Splendid evening, with some sheet lightning.
Weather continues beautiful, though the symp. and bar. remain low. Sheet lightning in the evening.
Weather as yesterday. Symp. fell to 27.54; temp. 76.4; and bar. was depressed to 25. 12 by four
o'clock P.M.; dew point 70, black ball ; and 76 covered ball. No rain. Wind south and gentle
till four o'clock, P.M., then was NN.W., strong and squally ; and the weather became overcast.
Thunder and appearance of storm in the N. and N.W, Star-light evening and night.
The quantity of rain which has fallen during the last fifteen days amounts only to iVo- Tne weather
has generally been beautiful, and such (as it is said) is rarely experienced at this season of the year.
The ground has become arid, and dust is flying about as in the dry season : rain much wanted.
Though for the last week, and especially during the last three days, the instruments and appearances
lead again and again to the expectation of rain, yet till yesterday evening at half past 9 P.M. we
had none. Distant thunder; though little rain has fallen here, I believe much has fallen in the
vicinity. The symp. stood at 27.52, temp. 75.20 ; weather sultry. Bar. 25.60. Wind went to the
N.W., and was strong and squally at 4 P.M. Dirty appearances. Sheet lightning in the evening.
Fine clear weather, with scattered clouds, till four o'clock, P.M., when it rained. Symp. and bar.
rising: indeed the latter rose to 25.18, though there were showers last night. Some thunder.
Sheet lightning in the evening.
Forenoon fine, warm, and sultry. In the afternoon, a good deal of thunder. Weather cloudy.
Appearance of rain all round the capital. Much sheet lightning in the evening.
Weather cloudy all day. Thermom. at eleven o'clock, A.M. 72'20 ; at noon, only 69'30 ; at one o'clock,
P.M., 71-50, in consequence of the fall of trifling showers. Sheet lightning in the evening. Although
showers fell in the afternoon, evening, and night, yet symp. and bar. kept on the ascent. The
statement of the weather for last ten days merits particular attention.
Weather cloudy the whole day : at ten o'clock A.M., drizzling rain, which also took place at different
times, but in all was very trifling; yet the symp. ascended to 27.98, and the bar. to 25.38 j after-
wards they slowly fell to their present state. Sheet lightning in the evening.
Cloudy weather, but fine ; trifling showers, especially about three o'clock, P.M. Fine moonlight and
starlight evening. Bar. rose to 25.38, but fell again in the night.
Weather fine, and generally clear, with now and then scattered clouds. Morning fresh. Climate, upon
the whole, delightful and healthy. Evening moonlight and clear, except at intervals, in conse-
quence of rapidly passing clouds. Some sheet lightning.
Weather tine, fresh morning ; most agreeable at noon, in consequence of the sun's influence, became
very warm in the afternoon ; beautiful evening. Fine morning.
Beautiful weather ; splendid evening.
Fine weather. Temp, moderate. Sometimes cloudy in the evening. Clear in night. Morning foggy
in the east.
Fine day; but as the wind was nearly constant, and the temp, never high, at times, rather fresh.
Afternoon cloudy. Rain showed itself in the last twenty-four hours.
Fresh morning. Shower of rain. Fine agreeable healthy weather. Evening pleasant.
Weather continues good ; though part of the last twenty-four hours it was sometimes cloudy, espe-
cially in the v.w. : a little rain fell. Wind strong in the night. Cloudy morning, especially towards
the N.K. Threatens rain.
Weather cloudy, often threatened rain ; but the quantity that fell during the last twenty-four, and
the preceding forty-eight hours, did not amount to more than -ji^ of an inch. Still cloudy.
Weather cloudy all day, with trifling showers and strong breezes. Fresh. Still cloudy this morning.
(Jowl healthy weather, though sometimes cloudy.
Ditto, the wind lias varied little for some time past ; the breezes have generally taken place in the
night, or with showers. The quantity of rain that has fallen this month forms a great contrast
to what fell in December, 1828, viz. 12 inches ; and what fell in January, 1829, viz. 14*02 inches.
Aurora borcalis in the evening.
54 JOURNAL of the WEATHER at TANANARIVOU, Capital of
|
March
Baro-
meter.
Thermometer.
Hygrometer.
Rain.
WIND.
Max.
Min.
Dew Pt.
Direction.
Force.
1
25-32
70-7
59
63
59
' -
ENE
Moderate with
breezes
2
25-30
70.2
61
65
64
• •
ENE E & calm
Do.
3
25-28
74
59
64
60
E & calm
Do.
4
25-25
76-1
62
68
66
273
E
Do.
•
5
25-26
75-4
55
67
65
•60
E & calm
Gentle with breezes
6
25-25
72
62
69
66
2-26
Do.
Do.
7
25-29
72-4
64
667
66
•48
ENE & calm
Do.
8
25-30
71-2
62
67
66
1-33
E NE &E
Do. ^
9
25.28
67-6
59-4
63
66
•68
E calm & E
Gentle
10
25-28
71-5
61-4
67
65
1-75
E & calm Do.
11
25.29
71-3
60-4
65
63
.45
ENE&E
Do.
c
12
25-32
70
62
67
65
1-43
E&NE
Moderate
13
25-30
71-3
61
68
62
•73
Do.
Do.
—
14
25-26
73-8
58
67
67
•01
Do. & NW
Do.
15
25'28
73-2
62-4
69
67
.
NW
Do.
16
25-22
72-8
63
68
66
•
Do.
Do.
17
25-28
75-6
63-2
69
67
•01
NW&E
Gentle
18
25-30
71
60
66
62
•85
Do.
Moderate
19
25-30
72-2
61-2
67
65
.
NE&E
Do.
0
20
25-37
72-6
62
67
64
.
E
Gentle
21
25-37
72-3
60-5
64-5
61
.
E
Gentle in the day,
strong all night
22
25-35
72-4
59
64
62
.
E & calm
Moderate
23
25-32
71-8
f>9
0S
63
.
Do.
Do. with strong
breezes
24
25-31
72
60
66
64
.
Do.
Gentle with breezes
25
25'29
72'4
60-2
65'5
64
t •
Do.
Do.
MADAGASCAR, for the Month of MARCH, 1829. 55
GENERAL OBSERVATIONS ON THE WEATHER, &c.
Fine weather, though sometimes cloudy. A Scotch mist for a few minutes. Partial rainbow in th
east at 5, P.M.
Delightful day, but at times cloudy. Symp. and bar. fell, however, yesterday afternoon, and remain
low. Dull morning.
Weather as yesterday. Bar. fell T^ and remains at 25 '29. Symp. §ame as yesterday. Aurora
borealis in the evening.
Symp. and bar. fell after noon, about 2 P.M., heavens became overcast all around, and at 3 a heavy
shower fell. Rainbow in the taut ut 5 P.M. In the evening much thunder and lightning, and rain
alternating with fair intervals, during which many beautiful coruscations, and much sheet light
ning illuminated parts of the hemisphere. Much rain in the night. Foggy morning.
Forenoon fine. Sultry. Thunder and lightning. Dark wet evening, except when illuminated b)
sheet lightning. Raining heavily at present.
Gentle rain during greatest part of the day with heavy showers j much rain in the night. Foggy
morning.
Weather cloudy, with now and then heavy showers. Atmosphere sultry and oppressive. No thunder
Some lightning in the evening. Foggy mild morning.
Fine forenoon. Showers and gusts of wind from the N.K. Rained all night, but not heavily. Stil
raining gently. The low lands are completely inundated.
Fresh and rather cold day. Long continued scattered rain, both in the day and the night. Symp
and bar. not much affected yesterday, but have descended a little in the night. Cloudy morning.
Cloudy, mild, but disagreeable weather. Surrounding country much inundated.
Bad weather. Inundation of the country in some parts very complete. Alarm was sounded at 5
this morning, that the river Kioupa had burst through its banks to the south. The quantity of
stagnated water is therefore likely to be much augmented. Symp. and bar. have operated in con-
trary direction. Foggy morning.
Fine weather and showers alternately during day. Good deal of distant thunder and lightning,
Heavy showers in the evening and night. Foggy morning.
Showers and sunshine. Pretty good weather in the intervals. Some thunder and lightning. Shee
lightning in the evening. Foggy morning.
Some distant thunder after 4, just before which there was a smart breeze from the w., accompanied
by a trifling shower. Fog this morning.
Weather fine, but the plain surrounding Tananarivou is BO inundated as in many places to resemble
ponds and lakes.
Fine weather. A good deal of sheet lightning in the evening. Notwithstanding the fall of the
symp. and the bar. Morning beautiful.
Some distant thunder was heard, but only O'l of rain has fallen the last 24 hours. Fog early this
morning which has changed to a Scotch mist.
Fine weather till 1 P.M., when there was a shower. Symp. and bar. fell. A good deal of thunder
and much evening lightning. Heavy rain in the night. Appearance of fair weather this morning.
Weather fine and healthy. As the country still is, and is likely to be for some time to come, inun-
dated, the air is moist. Distant thunder. Sheet lightning in the evening. Fine morning.
Fine weather. Beautiful moon-light evening with some sheet lightning. Hazy in the S.E. this
morning.
Fine weather continues. Aurora borealis in the evening. Cloudy in the K. and s., but with other
favourable indications.
Weather very fine, yet when two black clouds passed there was for two or three minutes a Scotch
mist. Sheet lightning in the evening.
Beautiful day. Sky clear before 6. Cloudy morning.
Weather continues charming. No rain last twenty-four hours, notwithstanding fall of symp. and bar.
Fine weather. Sheet lightning in the evening. Mr. Lyall had scarcely registered the above obser-
vations, when he was made a prisoner at the instance of the gods of Madagascar, torn in a moment
from his family and removed to Ambouhipaina, seven miles east of Tananarivou.
56 Mr Lyall on the Weather in Madagascar.
GENERAL OBSERVATIONS.
1. TANANARIVOU, the capital of Madagascar, is situated in 18° 56' 20"
S. L., and, I conjecture, in about 47° E. L. From barometric obser-
vations, I reckon its elevation to be nearly five thousand feet above
the level of the sea ; and its highest pinnacle, called Ambouin Sim-
boun, about seven hundred and fifty feet above the level of the greatest
part of the surrounding plain. I am about to make extensive and
more accurate observations respecting some of these points, which I
shall not fail, in due time, to make public.
2. In consequence of the peculiar situation of Tananarivou, and
especially of its great elevation, a series of well-conducted and well-
recorded meteorological observations must be of the highest interest.
By the acquisition of additional instruments, and greater practice, I
trust to render every month's report more detailed and more interesting
than another, until the climate here is sufficiently known.
3. The observations have been made every morning at six o'clock,
because this is the only hour on which I could count for regularity :
therefore, the day commences at six o'clock, A. M., and ends at six,
A. M., of the succeeding day.
4. The sympiesometer used is Adie's, No. 497.
5. In consequence of an accident having happened to one of
Newman's mountain barometers (an excellent instrument), I have
been compelled to make the foregoing observations with Jones's
mountain barometer, which is constantly suspended. In order to
have the means of making comparative observations, however, I my-
self filled the tube of Newman's barometer, which, though the starting
point be somewhat different, acts upon the same general principles and
in the same manner as Jones's. The two instruments work together.
6. Rutherford's register thermometer is used for the maximum and
minimum.
7. In all my observations with the sympiesometer, after carefully
adjusting thejtfewr de lis, I find it necessary to attribute 10, 12, 14,
16, or even more degrees to the mere effect of temperature, between
the hours of one or two o'clock and four o'clock, p. M. ; otherwise I
should be constantly predicting rain.
8. Daniell's hygrometer is used.
9. I have given a statement of facts, without attempting to draw
conclusions. Time does not permit such inquiries ; besides, professed
meteorologists will do this much better than I could : therefore, copies
of this table, and of that of all future tables, shall be forwarded to my
friends, Mr. Dalton, of Manchester, and Mr. Daniell, of London.
ROBERT LYALL.
ON THE ELUCIDATION OF SOME PORTIONS OF THE
FABULOUS HISTORY OF GREECE,
BY THE APPLICATION OF THE ANALYTICAL PRINCIPLES OF PHILOLOGY.
BY WILLIAM SANKEY,
A.M. of the University of Dublin, and ad eundem of Cambridge, &c.
TN a former essay I directed my attention to the legitimate
L principles which should guide us in the analysis of lan-
guages, and applied the same to the investigation of the origin
of some of the distinguishing characteristics, as well as apparent
anomalies, of the Greek tongue. I would now bring the prin-
ciples to bear upon points still more interesting, as shewing us
that this is a subject which does not confine its views to the
mere mechanism of language, but that it may be advantage-
ously employed in enabling us to arrive at the accurate mean-
ings of words on the one hand, or, on the other, in throwing
light upon the darker ages of history, while as yet dawning
through the thick mists of fable.
With respect to the assistance we thus derive in ascertaining
the appropriate meanings of words, we may exemplify this in
the word Xaor, a people, which however, analytically, signifies
more accurately a multitude, being obviously resolvable into
the radix Xx and oy. Now, Xa is clearly the same as the
particle Xa, valde, presenting, therefore, at once, in the com-
pound Xst-os-, the idea of largeness. We are also enabled thus
immediately to detect the error of the older etymologists,
who, being unacquainted with the just principles of analytic
philology, deduced Xaos-, a people, from Xa*$-, a stone.
Again, to take the particle <$s : this word generally ranked as
an adversative, but we shall probably be led to question the
justness of this classification when we consider that $e is closely
allied in sensible character to £s-o;, ligo, from which it is at
once obtained by a direct analysis. The idea, therefore, con-
veyed by this particle £e, must be connected with that of bind-
ing. This will further appear from its affinity to £si, oportet,
which is, indeed, the third person singular of the former verb
Sew, the notion of a physical restraint, which is primarily con-
veyed by this latter being metaphorically transferred in what is
called the impersonal $a, to a moral obligation. Hence then
58 Mr. Sankey on the Philological Analysis
it follows that £e should be ranked amongst the conjunctions
copulative, and not among the disjunctives, as it has been
generally classed by grammarians and lexicographers. Indeed,
when we consider the very forced and inelegant construction
which, following the present rendering of this particle, is com-
monly given to sentences wherein it occurs, we might be apt
a priori to doubt whether its proper meaning had been yet
assigned. In truth, I believe there will be found but few
passages in which the sense would not be much improved by
taking $& as a connective, instead of an adversative. I do not,
however, deny, but that in some instances it may be used with
somewhat of a disjunctive signification. For example, where
it is put, as it were, in opposition to /u,sv. Even in these
instances, however, the meaning would not be much obscured
by rendering £s as a copulative. Perhaps, in such cases, the
force of £e might be very well given by the English yet, which
is itself derived from the Latin copulative et, and that from the
Greek ert, moreover. This view of £s, as a connective, may
receive still further support from the consideration that this
particle is closely allied in sensible character to the copulative
re, the difference lying solely in the interchangeable letters £
and T. Now rs unquestionably signifies and, the same as
xat, with which also it is frequently used, xai being put in the
former member of a connected sentence, whilst rs occupies the
latter. But £s itself is also sometimes used in the same manner
after xai. Indeed, in most of those instances in which TE is
used, it will be found that &e, according to the laws of enun-
ciation, would necessarily be pronounced TE, the £ being changed
into r, as occurring after v or a. It is true indeed that £s is
sometimes found following after having an apparent connection with
tmrnpi a mother, and by the force of a false etymology
being supposed to be quasi yn wrnp9 the Greeks have there-
upon raised a fabulous allegorical structure.
A further confirmation of this view is to be found in the
Latin term Ceres, which corresponds to the Greek A*j//.r/?7)p.
For Cer-es, as we have remarked before of Kopj, is also mani-
festly derived from %zip-u, tondeo. The c, however, of the
radix being retained in Cer-es is a proof that its signification is
connected with the action of the verb in a present and active
energy, whilst the plural termination es shews that this word
60 Mr. Sankey on the Philological Analysis
was not originally limited merely to a single individual.
Ceres, therefore, analytically and primarily, meant the shearers
collectively. So that the terms Ceres, Ksp-w and Core, Kopj,
in this respect answer to one another both etymologically and
physically, as cause and effect. From this instance we may
be led to perceive that much of the Greek mythology, which
was almost altogether physical, had its foundation in the
radical meaning of the appellative terms therein used.
Thus the origin of the numerous fables spread about Pro-
teus is at once explained on attending to the real import of
the Greek name TIpcJlsios, which being derived from irpaflos,
meant the first element ; this, many amongst the Greeks con-
sidered to be simple. Out of it, therefore, every thing mate-
rial being imagined to be produced by variety of combinations,
the fable accordingly took its rise, that Proteus, Ttpuleios, was
capable of assuming every shape.
Again, the Curetes, Kovpvflef, originally signified the winds,
being derived from %opw, verro, to sweep along.
In a double meaning of words, and the ambiguity thence
arising, originated the fable of Cadmus and the offspring of
the dragon's teeth. The history, as deduced from the fable,
seems to have been simply this : Cadmus brought with him
into Greece many of those improvements which Asia, as ear-
lier inhabited, had already made in agriculture and the arts
of life. Amongst others he introduced the culture of the
avapTov, genista, broom, whose twigs were manufactured into
a species of cordage. This plant is of a deep copper or
serpent colour. Now, it is remarkable, that the same word
Briti in the Hebrew and Syriac or Phoenician languages, signi-
fies both a serpent and brass or copper, owing, no doubt, to
the similarity in the colour of these objects. Hence, there-
fore, it is likely, originated the mistake which gave rise to the
fable. For this word ttrnj, having probably been used by
Cadmus and his Phoenician followers, in reference to the colour
of the broom, it was erroneously interpreted, according to its
ambiguous meaning, as denoting a serpent. Hence, the seeds
of the broom were called serpents' teeth, which they might
themselves also be fancied somewhat to resemble in size, &c. ;
and so they were fabled to be particularly the teeth of one of
of the Fabulous History of Greece. Gl
the larger of those noxious reptiles which, as much infesting
the adjacent parts, Cadmus, in clearing the country for his
new settlement, had but a short time before destroyed. The
ambiguity of the word mraplov, also, which etymologically may
signify anything sown, contributed to spread the error. The
genista having been sown in drills, as in an oziery, with its
upright form and spear-like branches very naturally presented
an appearance somewhat like that of a battalion of armed men,
to which the imagination would find a still further resemblance
in the helmet- shaped carina of its papilionaceous flower. In
accordance therefore with this view, the cutting down of the
plant for the purposes of manufacture would be represented
as a mutual combat amongst the offspring of the dragon's
teeth, ignorance, credulity, and fear, coupled with a lively
imagination, easily converting the strenuous labours of the
workmen into a mutual assault of combatants. The survivor
or survivors, as the fable has it, were clearly the labourers
employed by Cadmus, who having been at first concealed by
the standing broom, and afterwards becoming visible on its
being cut down, were imagined to be the remains of the crop
of armed men ; and these same workmen, as being his ordi-
nary attendants, probably themselves also Phoenicians, further
assisted Cadmus in building the walls of Thebes. I am aware
that this fable has been otherwise explained, as resting altoge-
ther upon the ambiguity above remarked, of the Phoenician
word DPI:, which signifies both a serpent and brass, as though
the dragon referred to a king armed in brass who was over-
come and killed in battle by Cadmus, and the seed of the
dragon's teeth to the scattered troops of the slain monarch's
subjects, that rose up in arms of the same brazen materials
upon his death. That, however, the explanation I have given
is more correct, will be evident from the similar achievement
of Jason, where we have, besides the account given of the very
preparation of the ground for the seed by the labours of the
oxen, a circumstance completely confirmatory of its being an
agricultural rather than a military exploit. What gives greater
weight to the argument derived from this source is the close
connection in every point of view between this feat of Jason
and that of Cadmus, notwithstanding the interval of time that
62 Mr. Sankey on the Philological Analysis
had elapsed between them, and the distance at which Colchis
lay from Thebes : for Phryxus, himself a native of Thebes,
and born during the lifetime of Cadmus, had probably brought
along with him, on his flight from Bceotia, the seeds of [the
ffwaplov, the culture of which, as we have seen, had been
already introduced into that country by Cadmus. Hence,
therefore, the merit of Jason in this particular will consist in
the readiness with which he learned the sowing, rearing, and
management of this plant in all its stages, as also the skill with
which he guided the plough drawn by brazen-shod oxen.
For such is the true history, when divested of fable, of the
brazen-hoofed bulls ; whilst the panting breathing of the
smoking animals, blown with their exertions in ploughing a
heavy soil, gave rise to the poetic exaggeration that they vo-
mited forth flames of fire.
From this view of the history of one part of the Argonautic
expedition, I am naturally led to notice another instance, con-
nected with another part, where the ambiguity of a name gave
rise to a very remarkable mistake. The Argonauts, cut off in
their retreat from Colchis through the Euxine Sea by the outlet
of the Hellespont, were necessarily driven northwards to the
Palus Maeotis, whence, the country about the mouths of the
Tanais and the Vistula being probably at that time under
water, they were enabled, by transporting their light vessel
but a short way across the land, again to launch into the deep.
Sailing therefore through the Baltic, and crossing the German
Ocean, they passed along the shores of the British Isles. Here
it was that, as they discerned the coasts of Ireland, the melan-
choly coincidence of a name raised in their superstitious bosoms
the most gloomy apprehensions. Informed, no doubt, that
this island was called Eirionn or Erin, as it is still denominated
in the Erse or Gaelic, the original language of the country,
those adventurers connected this appellation with the Greek
word Epiwus, a name which, derived from spis, strife, a sinful
idolatry had given to the imaginary inflictors of avenging
torments. Believing, therefore, that this island belonged to
these fancied tormentors, they were appalled at the circum-
stance ; and, struck with horror and remorse at the recollec-
tion of their conduct towards the Colchians, and the disastrous
of the Fabulous History of Greece. 63
fate of Absyrtus, they were naturally filled with the most
alarming terrors for their situation.
Another instance in which the application of true principles
of etymology will be found to afford us much assistance in
elucidating history, where it has been obscured by fable, is
that which relates to one of the most remarkable of the adven-
tures attributed to Perseus. I allude to that which refers to
his obtaining, as it was fabled, the Gorgon's head; an adven-
ture, as generally narrated, altogether incredible, but which,
when properly understood, is highly interesting, as giving us
an account of perhaps the earliest introduction, as it would
appear, of the coral into Greece, — at least of that species which
is called the Medusa's head. It is probable, indeed, that the
Tyrians, in their commerce with the Greeks, had brought
them specimens of the madrepore, and other coralline produc-
tions, at the same time describing the Medusa's head as being
of a rarer kind and more difficult to be obtained. A desire,
therefore, of obtaining this species, as well as of satisfying an
excited curiosity in visiting and exploring strange countries,
combined, it is likely, with general objects of a commercial
character, impelled Perseus to undertake what may be truly
called a voyage of discovery. That he indeed was considered
by the Greeks as having first made known to them the coral,
and that as one of the fruits of this expedition, is evidently to
be inferred from the epithet given to this natural production, the
coral) in that line of the poet, where the author expressly de-
nominates it, clearly in reference to this very fact, Persean, —
— Ilioff'/iioao filivo; (Aiyct, xoupuXioia.
The great strength of the Persean coral.
It is remarkable, also, that this author, after describing the
coral as being originally a vegetable production growing in the
depths of the sea, the saltness of whose waters withered its
leaves, and so left it, with its branches denuded and bare, to
float the sport of every wave, till, thrown at length upon the
shore, it indurated on being exposed to the air ; it is re-
markable, I say, that he connects the coral with the Gor-
gon's head, fabulously ascribing the deep colour of the red
coral to the effect of its being tinged with Medusa's blood.
64 Mr. Sankey on the Philological Analysis
Now, this explanation, though obviously false, marks the
local, or, so to speak, geographical affinity, which was at that
time admitted to hold between the coral and the Gorgon's
head, and that both were considered to have been obtained
from the same place. The truth is, that the error has arisen
here from the ambiguous etymology of the name xopaX^wv, or
xoup&Xiov. This word, analysed, is evidently a compound of
two distinct words, xwpn or xo^-xj, and aXr, mare. Now we
have already seen, that the first part, xopj, etymologically
signifies the harvest. Hence xoi^aXXtov or xopaXXtov analyti-
cally means the harvest of the sea — an expression which, as
very happily designating those resemblances of vegetable life
which grow, as it were, beneath the bosom of the deep, was a
most appropriate appellation for those crops of coral which
Perseus brought home with him. The Greeks appear, how-
ever, to have been misled here also, as in the fable of Ceres
and Proserpine, by the more common acceptation of the word
xopn, and so interpreted the compound xoupzXiov, as though it
signified the girl of the sea. This interpretation may also have
received some further support from Perseus having possibly
encountered and slain, in this expedition, one of the native
queens of the country which was the more immediate scene of
his exploits. We need not, therefore, be surprised that, in
conformity with this view, it was imagined that the Medusa
coral, with which Perseus, it would appear, adorned the boss of
his shield, was the head of a female, as that species of coral
bears some resemblance to the human face, especially that of a
woman encircled with heavy ringlets of thick curling hair.
Even though we suppose the name to have been originally
derived from xopy, puella, and from this fanciful resemblance
given primarily to this species, but afterwards extended to
corals in general, this will still nowise militate against the view
I have taken of the origin of the fable, as grounded on the in-
troduction of the coral into Greece. Further, from their like-
ness to vegetable and animal life, corals were considered as
petrifactions ; and hence arose the idle tale, the offspring of
superstition and credulity, of the petrifying qualities of the
Gorgon's head, and of whole hosts of armies turned into stone
immediately on its being presented to their view by Perseus.
of the Fabulous History of Greece. 65
If we examine a little also into the origin of the other fabulous
circumstances recorded as connected with this adventure, we
shall find them also tending still further to confirm the view I
have been endeavouring to establish. Thus the wings and
talaria with which the supposed Hermes or Mercury is said to
have furnished Perseus, clearly signified nothing else than an
oared ship or ships with which he had been furnished probably
by the Tyrians ; the wings evidently denoting the sails, and
the talaria the oars. Even in the etymology of the name
Hermes, E/jpcw, we may find, perhaps, a stronger support for
this conjecture than at first view might be imagined. The
verb Epzaffu signifies to row in particular, and to navigate in
general; but verbs in oau are generally derived from, or rather
are but other forms of verbs in u or so>. Hence we are led to
an obsolete radix, spsu, of the same signification, from which,
according to the general analogy of the language, comes E/>/x,-r,s-,
the rower, navigator, or, more properly, being originally E/>/>t-ees-,
of the plural form, the rowers, navigators. The Greeks, how-
ever, naturally enough considered this word to have been de-
rived from £/>&;, dico, or perhaps sipoa, necto ; and from this,
and the circumstance that the communication between the
different parts of Greece and the chief seat of government
(which, it would appear, was at that time in Crete or Asia)
was carried on by means of sailing vessels, arose many of the
fabulous stories related of their Hermes or Mercury. Another
etymology might, perhaps, be assigned for this name Hermes,
which would no less agree with the main facts of the fable.
The radical part of Eppt-m, when analysed, is evidently E/;/x.
Now this, written in Hebrew characters, is Din, which, both in
the form of the radical letters and the pronunciation, is not
very dissimilar to DTH or DTin, the name of the king of Tyre
contemporary with David and Solomon. Under this view,
then, Hermes, E^/oc-yjy, being of the plural form, would denote
the seamen of king Hiram, and so point to the Tyrians as the
people who, from their maritime situation and habits, furnished
Perseus in particular with the ships necessary for his voyage,
as they had all along been the medium of intercourse between
the chief seat of government and the provinces of Greece. The
chronology, I may also remark, would herein agree with that
VOL. I. OCT. 1830. F
66 Mr. Sankey on the Philological Analysis
set forth by Sir Isaac Newton, who makes Acrisius, the grand-
father of Perseus, contemporary with David. Even, according
to the more received chronology, the name Hermes, Epp-ns,
may have been derived from a king of Tyre, as the appellation
of Hiram, which seems to have been not uncommon among the
Tyrians, may have been borne by others of their monarchs,
prior to him who was the friend of David and Solomon.
However this may be, it is remarkable that the Latin name
Mercurius, as well as the Greek, 'E/j/xojs-, seems originally to
have been of a plural form, Mercuri, — the terminal us being
afterwards added, in conformity with the erroneous notions of
a false theology. Hence, whilst the Greeks gave the appella-
tion E/5/X7JS-, either from the mode in which these foreigners
visited their shores as sailors, or from the name of the monarch
whose subjects they were, the Latins, on the other hand,
designated them, from their occupation as traders, Mercuri,
which word, indeed, considered as a translation of the ambi-
guous Hebrew word vys, will at the same time point out both
the pursuits in which they were engaged, and their original
parentage and country, viz., merchants, Canaanites. This
view will be found to agree very well with the various cha-
racters ascribed to Hermes or Mercury, so celebrated for elo~
quence and craft, for his skill in mercantile transactions, and
readiness in embassage, &c. It is supported also by the
fabulous history of his birth, as reported to be the son of
Maia. The personal existence of such a female may indeed
be well considered doubtful. The name, however, Maia, as
derived from ^y.iu, cupio, was obviously directly given, as a
very appropriate appellation, to the fifth month of the year,
our May — a month so desirable to mortals, after the gloom
and nakedness of winter, for the serenity of its skies, the fresh
verdure of its foliage, and the richness of its flowery blooms.
In the same season > also, navigation, which had been impeded
by the raging storms and the roaring seas of winter, was again
resumed. As, therefore, these Tyrian or Canaanitish merchant
mariners, \3jD, Mercuri, E^/AEE*, generally revisited the shores
of Greece and Italy in the month of May, they were allegori-
cally said to be the offspring of Maia ; and this, literally taken,
was afterwards transferred, as the real origin of his birth, to the
of the Fabulous History of Greece. 67
fictitious being Mercurius, who had been made, as it were, their
personal representative.
To return, however, to the fable of Perseus. I may just
remark, in further confirmation of the Medusa's head having
been a real coralline production, that Perseus is represented as
cutting down the coral with the apww, or sickle — the very in-
strument which he is said to have been furnished with for the
express purpose of cutting off the Gorgon's head ; but which,
in truth, it is clear he had really provided himself with, with a
view to this coralline expedition.
Many other instances might be adduced, in which an ana-
lytical investigation of the names of persons and things throws
light upon the history where it has been obscured beneath a
mass of fable. Such a view, indeed, of fabulous history, is
highly important. No doubt that which is called the fabulous
age of Grecian story is deeply involved in thick clouds of
obscurity ; yet here and there, through the breaks in the
gloom, we can dimly discern forms cast in the same mould with
ourselves. It will scarcely be denied, that most of the person-
ages which are spoken of as flourishing at that early period
did really then exist. The main body of the events in connexion
with which their names have been handed down to us, must
have had some foundation, in fact, more solid than the mere
imagination of the poet, or the fanciful story-telling of the
dealers in the marvellous. The early history of every people,
except that of the Jews, we find mingled with fable ; and this
has arisen, not merely from that love of the marvellous which
characterises a rude, untutored race, but also from the want of
those faithful records which, by presenting an accurate delinea-
tion of events, would, in a great measure, have corrected those
popular errors and delusions which have interwoven themselves
with the facts. Indeed, there exists at all times a class of
persons whose minds are prone to see everything under an
exaggerated form, and no less so to communicate their own
impressions with additional circumstances of exaggeration unto
others. Any person who is at all acquainted with the peasantry,
may have observed how distorted a form any more than
ordinary event will come to assume among them, as it is con-
reyed from mouth to mouth, even in the immediate neighbour-
F2
68 Mr. Sankey on the Philological Analysis of the
hood of the transaction. Unquestionably, these appendages
to the fact will vary much, both in tone and extent, according
to the peculiar character of the age and people. Still, we may
be certain that facts, orally transmitted, must, through a lapse
of time, receive a considerable degree of colouring from the
prevailing hues of the various media through which they are
transmitted. Many of the leading circumstances may be
altered, and not a few may be omitted, whilst some additional
ones may be grafted upon the original. The general outline,
however, still will have been drawn from fact. Amid all the
windings, therefore, and intricacies of the labyrinth, we need
not despair of being able to discover the thread which shall
serve to extricate us from the maze. It will be found, indeed,
I believe, that most of these fabulous legends may in general
be traced to — 1. Exaggerated descriptions. %. Mistakes in
the reasons and explanations assigned for any particular line of
acting, where that was such as might, perhaps, appear extraor-
dinary to persons unacquainted with the circumstances and
motives that influenced. 3. Allegorical representations of per-
sons and events. 4. Metaphorical language ; and 5, as above,
ambiguities of words. This last requires no further confirma-
tion, after the many instances we have already been consider-
ing, in which the foundation of the legend obviously rests upon
such ambiguities. In like manner, too, each of the other heads
might also be illustrated by appropriate examples, were it
not that this would lead us beyond the proper limits of this
Essay. I cannot, however, help adducing one which falls
under the second head, inasmuch as, though altogether
absurd, as at present narrated, it is capable of receiving the
simplest explanation ; I allude to the singular tale of the punish-
ment of the daughters of Danaus. The solution is clearly
this : The perforated vessels which the daughters of Danaus
filled with water were evidently clepsydrae, the use of which
they had brought with them from Egypt. The Greeks, how-
ever, in their then state of ignorance, could naturally enough
perceive no benefit to be derived from pouring water into
vessels merely for the purpose that it might run out again
through holes in the sides and at the bottom ; the more so as
this operation, being constantly repeated, seemed as endless as,
Fabulous History of Greece. 69
no doubt, it appeared to them unmeaning. Hence, therefore,
they imagined it was a retributive punishment inflicted upon
these females on account of their cruel murder of their hus-
bands. What may, perhaps, add confirmation to this view of
the fable, is the fact recorded by Diodorus Siculus respecting
the priests of the temple of the false god Osiris in Egypt ;
namely, that they filled three hundred and sixty milk bowls
every day. Sir Isaac Newton, in his Chronology , imagines
that the historian here means that the priests filled each day
one bowl out of three hundred and sixty bowls, counting
thereby the days of the Egyptian calendar year. Now it is
probable that these bowls were clepsydrae, each running for
twenty-four hours, thus noting also the time of the day, by
being adjusted with something of a graduated scale, according
to the descent of the fluid. They would answer, therefore,
the double purpose of a diurnal time-piece and of an annual
calendar. Taking, however, the historian according to the
more obvious meaning of his words, namely, that the priests
filled the whole number of the three hundred and sixty bowls
every day ; then, if each bowl ran exactly four minutes, and
they were filled by these numerous attendants accurately in
succession, the entire cycle would be completed just in the
twenty-four hours ; so that these four-minute chronometers
would give precisely the time of the day. Commencing also
every day one bowl lower down, if I may so say, in the order,
then the days of a year of three hundred and sixty days would
be likewise kept by the number of the bowl with which they
began each day. Indeed, were we even unable to assign any
probable reason for this custom, still it would serve so far to
explain the fable of the Danaides ; inasmuch as, Egyptians
as they were by birth, there can be but little doubt but that
they carried with them into Greece their Egyptian predilec-
tions and Egyptian rites. Hence, therefore, we might natu-
rally expect to find some notice, though tinged as it is with
fable, of their having adopted this Egyptian custom of pouring
a fluid into perforated vessels, and that, no doubt, with the
same view, whatever that might be, with which it was origi-
nally practised in their native land.
ON THE LIMITS OF VAPORISATION.
BY M. FARADAY, F.R.S.,
Director of the Laboratory of the Royal Institution, &c. &c.
T WAS induced some time since to put together a few remarks
and experiments on the existence of a limit to vaporisation,
which were favoured with a place in the Philosophical Transac-
tions for the year 1826. When the experiments there men-
tioned were published, I arranged some others bearing upon
the same subject, but which required great length of time for
the developement of their result. Four years have since
elapsed, during which, the effects, if there had been any, have
been accumulating, and it is the object of this brief paper to
give an account of them.
The point under consideration originally was, whether there
existed any definite limit to the force of vaporisation. Water
at 220° sends off vapour so powerfully, and in such abundance
as to impel the steam-engine ; at 120° it sends off much less ;
at 40°, though cold, still vapour rises ; below 32°, when the
water becomes ice, yet the ice evaporates; and there is no cold,
either natural or artificial, so intense as entirely to stop the
evaporation of water, or in the open air prevent a wet thing
from becoming dry.
The opinion of many, among whom were the eminent names
of Sir H. Davy and Mr. Dalton, was, that though the power
of evaporating became continually less with diminution of tem-
perature, it never entirely ceased, and that therefore every
solid or fluid substance had an atmosphere of its own nature
about it and diffused in its neighbourhood ; but which being
less powerful as the body was more fixed, and the existing
temperature lower, was, with innumerable substances, as the
earths, metals, Sec., so feeble as to be quite insensible to ordi-
nary or even extraordinary examination, though in certain
cases they might affect the transmission of electricity ; or, rising
into the atmosphere, produce there peculiar and strange results.
The object of my former paper was to shew that a real and
distinct limit to the power of vaporisation existed, and that, at
common temperature, we possess a great number of substances
Mr. Faraday on the Limits of Vaporisation. 71
which are perfectly fixed. The arguments adduced, were
drawn first from the power of gravity, as applied by Dr.
Wollaston, to shew that the atmosphere around our globe had
an external limit, and then from the power of cohesion ; either
of these seemed to me alone sufficient to put a limit to vapori-
sation, and experiments upon the sufficiency of the latter force
were detailed in the paper.
The conclusion was, that although such substances as ether,
alcohol, water, iodine, &c., could not as such be entirely de-
prived of their vaporising force, by any means we could apply
to them, but still, if in free space or in air, would send off a
little vapour, yet there were other bodies, as iron, silver, cop-
per, &c., most of the metals, and also the earths, which were
absolutely fixed under common circumstances, the limit of
their vaporisation being passed; and further, that there were a
few bodies, the limits of whose vaporisation occurred at such
temperatures as to be within our command, and therefore
passable in either direction. Thus mercury is volatile at tem-
peratures above 30°, but fixed at temperatures below 20°, and
concentrated sulphuric acid, which boils at temperatures about
600°, is fixed at the ordinary temperature of the atmosphere.
It is well known in the practical laboratory that vaporisation
may be very importantly assisted so as to make certain pro-
cesses of distillation effectual, which otherwise would fail.
Thus with the essential oils, many of them which would re-
quire a high temperature for their distillation if alone, and be
seriously injured in consequence, will, when distilled with water,
pass over in vapour with the vapour of the water at a much
lower temperature, and, being condensed, may be obtained in
their unaltered state.
It has been supposed that the vapour of the water, either by
affinity for the vapour of the essential oil or in some other
way, has increased the vaporising force of the latter at the
temperature applied, and so enabled it to distil over; but
there is no doubt that if air or any other similar elastic medium
were made to come in contact with the mass of essential oil at
212° in equal quantity, and in a manner to represent the
vapour of water, it would, according to well known laws, carry
up the vapour of the essential oil perhaps to an equal extent,
72 Mr. Faraday on the Limits of Vaporisation.
and pass it forward ; only the facility with which the carrying
agent is condensed when it consists of steam, allows of the
condensation of every particle of the essential oil vapour,
whereas the permanency of the elastic state of the air would
cause it to retain a large proportion of the vapour of the oil
when cold, and consequently a diminished result would be
obtained.
There are, nevertheless, some appearances which seem to
favour the idea that occasionally water favours vaporisation
beyond what air, equal to the bulk of the vapour of the water,
would do in the manner referred to above ; and it was to ascer-
tain whether substances which, from a consideration of the
general reasoning already referred to, and the high tempera-
ture at which they sensibly volatilized, might be considered as
fixed at common temperatures, could have any sensible degree
of volatility, in conjunction with water or its vapour, conferred
upon them at ordinary temperature. It is well known that a
theory of meteoric stones has been founded on the supposition
that the earthy and metallic matter found in them had been
raised in vapour from similar matter upon the earth's surface ;
which vapours, though extremely attenuated and dilute at first,
gradually accumulated, and by some natural operation in the
upper regions of the atmosphere became condensed, forming
those extraordinary masses of matter which occasionally fall to
us from above. The theory has in its favour the remarkable
circumstance, that, notwithstanding many substances occur in
meteoric stones and iron, yet there is none but what also occur
on this our earth * ; and it also has a right to the favouring
action of water, if there be such an action ; because vaporisa-
tion is one of the most important, continual, and extensive
operations that goes on between the surface of the globe and
the atmosphere around it.
In September, 1826, several stoppered bottles were made
perfectly clean, and several wide tubes close at one extremity,
so as to form smaller vessels capable of being placed within
* This very striking circumstance does not prove that aerolites in any way
originate from our planet j but then, if we could by other arguments deduce that
they were extraneous, it would lead to the conclusion that the substances which
have been used in the construction of this our globe, are the same with those
•which have been used extensively elsewhere in the material creation.
Mr. Faraday on the Limits of Vaporisation. 73
the bottles, were prepared. Then selected substances were
put into the tubes, and solutions of other selected substances
into the bottles : the tubes were placed in the bottles so that
nothing could pass from the one substance to the other, except
by way of vaporisation. The stoppers were introduced, the
bottles tied over carefully and put away in a dark safe cupboard,
where, except for an occasional examination, they have been
left for nearly four years, during which time such portion of
the substances as could vaporise have been free to act and
produce accumulation of their specific effects.
No. 1. The bottle contained a clear solution of sulphate of
soda with a drop of nitric acid, — the tube, crystals of muriate of
baryta. One half or more of the water has passed by evapo-
ration into the tube, and formed a solution of muriate of baryta
above crystals, but both that and the remaining solution of
sulphate of soda is perfectly clear ; there is not the slightest
trace of sulphate of baryta in either the one or the other, so
that neither muriate of baryta nor sulphate of soda appear to
have volatilised with the water.
No. 2. Bottle, solution of nitrate of silver; tube, fused chlo-
ride of sodium. All the water has passed from the nitrate of
silver to the salt ; but there is no trace of chloride of silver
either in one or the other. No nitrate of silver has sublimed
with the water, nor has any chloride of sodium passed over to
the nitrate.
No. 3. Bottle, solution of muriate of lime ; tube, crystals of
oxalic acid. The water here remained with the muriate of
lime. In the tube, the oxalic acid when put in had formed a
loose aggregation, with numerous vacancies, and with a very
irregular upper surface about an inch below the upper edge of
the tube. No particular appearances occur in the vacancies;
but at the top there has evidently been a sublimation of the
oxalic acid, for upon the crystals and glass new crystals in
exceedingly thin plates and reflecting colour have been formed ;
these rise no higher in the tube than to the level of the most
projecting part of the original portion of oxalic acid ; no
appearance of sublimation is evident above this, and it seems
as if the most elevated parts of the salt have given off vapour,
which has sunk and formed crystals on the neighbouring
74 Mr. Faraday on the Limits of Vaporisation.
lower surfaces, but that no vapour has risen to the upper part
of the tube. On examining the solution by a drop or two of
pure ammonia, it was however found that a slight precipitate
of oxalate of ammonia occurred. The experiment shews,
therefore, that oxalic acid is volatile at common temperatures,
and had not only formed crystals in the tube, but has passed
over to the solution of lime.
No. 4. Bottle, solution half sulphuric acid, half water; tube,
crystallized common salt. No water has passed to the salt.
On opening the bottle, the clear diluted sulphuric acid was
examined for muriatic acid, but no trace could be found.
Hence chloride of sodium has not been volatilised under these
circumstances.
No. 5. Bottle, solution of muriate of lime ; tube, crystals of
oxalate of ammonia. The oxalate of ammonia appeared quite
unchanged. The solution of muriate of lime was perfectly
clear ; but when a little pure ammonia was added to it, a very
faint precipitate of oxalate of lime was produced.
No. 6. Bottle, little solution of potash ; tube, white arsenic
in pieces and powder. This bottle was opened because of the
appearances, in October, 1829, and had then remained three
years undisturbed. The arsenious acid was to all appearance
unchanged. The solution of potash was turbid and foul. On
chemical examination, it proved to have acted powerfully on
the glass. It had dissolved so much silica as to become a soft
solid, by the action of an acid, and it had also dissolved a con-
siderable quantity of lead ; but there was no trace of arsenious
acid in it; so that this substance, although abundantly volatile
at 600°, had not risen in vapour when aqueous vapour and air
was present at common temperatures.
No. 7. Was some of the sulphuric acid used in these expe-
riments, preserved for comparison.
No. 8. Bottle, solution half sulphuric acid, half water ; tube,
pieces of muriate of ammonia. When this bottle was opened,
the pieces of muriate of ammonia presented no appearance of
change ; there was no moisture about them, nor any ap-
pearances of dissection that I could distinguish. The diluted
sulphuric acid being examined by sulphate of silver, gave no
appearances of muriatic acid; so that muriate of ammonia
appears fixed under these circumstances.
Mr. Faraday on the Limits of Vaporisation. 75
No. 9. Bottle, a little solution of persulphate of iron ; tube,
crystals of the ferro-prussiate of potash. Both were un-
changed ; there was no appearance of Prussian blue about
either the crystals or solution ; neither of the salts had been
volatilised.
No. 10. Bottle, a little solution of potash ; tube, fragments
of calomel. Here the potash had acted upon the glass, as in
No. 6; but, with respect to the calomel, the volatility of which
was in question, there was not the slightest trace of such an
effect. No black oxide nor other substance existed in the
potash solution which could allow the presumption that any
calomel had passed.
No. 11. Bottle, solution of potash; tube, fragments of cor-
rosive sublimate. Here the potash had acted on the glass as
before ; carbonic acid had also gained access by the stopper ;
so that no caustic potash was present ; but there were distinct
appearances of the sublimation of corrosive sublimate, and
minute crystals of the substance were even attached to the
under part of the stopper in the bottle. Hence corrosive
sublimate is volatile at common temperatures.
No. 12 and 13. Bottles, solution of chromate of potassa;
tubes, in one, chloride of lead in powder, in the other nitrate of
lead in crystals. In both these experiments the chromate of
potash had acted upon the lead of the glass, and rendered it
yellow and dim ; so that no indication could be gathered
relating to the non-volatility of the compounds of lead.
No. 14. Bottle, solution of iodide of potassa ; tube, chloride
of lead. Both remained unaltered; the solution of iodide was
perfectly clear and colourless ; no trace of the chloride of lead
had passed over in vapour.
No. 15. Bottle, solution of muriate of lime; tube crystals of
carbonate of soda. A part of the water has passed to the car-
bonate of soda; but both it and the remaining solution of
muriate of lime are perfectly clear. No portion of either salt
has volatilised from one place to another.
No. 16. Bottle, dilute sulphuric acid ; tube, nitrate of am-
monia in fragments. The nitrate was slightly moist. The
acid being examined was found to contain nitric acid, whilst
the test acid, No. 7, was perfectly free from it. It would
76 Mr. Faraday on the Limits of Vaporisation.
therefore appear that nitrate of ammonia is a salt volatile at
common temperatures, although it is just possible that slow
decomposition may take place in it, and so nitric acid or its
elements pass over.
No. 17. Bottle, solution of persulphate of copper ; tube,
crystals of ferro-prussiate of potash. The crystals had
attracted most of the water from the cupreous salt ; but the
solution of ferro-prussiate and that of the copper had their
proper colour ; neither were rendered brown ; no salts had
been volatilised.
No. 18. Bottle, solution of acetate of lead ; tube, iodide of
potassium. The acetate of lead is now dry ; the iodide of
potassium has taken all the water and formed a brown solution,
in which there is free iodine ; probably a little acetic acid has
passed over and caused the change in the iodide of potassium.
There is no appearance of iodide of lead in the tube, but there
is in the bottle, and most probably in consequence of the
vaporisation of the free iodine from the solution in the tube.
From these experiments it would appear that there is no
reason to believe, that water or its vapours confer volatility,
even in the slightest degree, upon those substances which alone
have their limits of vaporisation at temperatures above ordi-
nary occurrence, and that consequently natural evaporation
can produce no effects of this kind on the atmosphere.
It would also appear that nitrate of ammonia, corrosive
sublimate, oxalic acid, and perhaps oxalate of ammonia, are
substances which evolve vapour at common temperatures.
Royal Institution, Aug. 30, 1830.
( 77 )
ON THE EFFECTS OF ELECTRICITY UPON MINERALS
WHICH ARE PHOSPHORESCENT BY HEAT.
BY THOS. J. PEARSALL,
Chemical Assistant in the Laboratory of the Royal Institution.
D
(URING some experiments, made to observe the effects
of an electrical discharge passed over the variety of fluor
spar called chlorophane, which is peculiarly distinguished for
its phosphorescence when heated, I remarked certain appear-
ances, which are detailed in the following investigation.
When the electrical discharge is passed over fragments, or
the coarse powder of a very fine specimen of chlorophane, a
brilliant green light is produced. On repeating the experi-
ment many times, I found the phosphorescence re-occurred
with each repetition of the discharge, and was even sensibly
strengthened by the operation .
This striking appearance induced me to suppose that even
such minerals as had been deprived of the power of phospho-
rescing by calcination might have it restored by virtue of
electric action, and led me to make the following experiments,
which will shew how far this supposition was confirmed.
A specimen of chlorophane, possessing naturally the pro-
perty of phosphorescence in a very high degree, was first
subjected to the action of heat. The light emitted was co-
loured, first bluish-green, very bright ; then pinkish, blending
with pale-whiteness as it became red-hot, when it lost all
peculiar light.
A portion of the same mineral, which had been calcined,
and thus deprived of its power of phosphorescence, was then
subjected to a single discharge from a small Leyden jar, of
about a square foot of coated surface. The substance became
luminous during the passage of the electricity, producing a
green light.
On the application of heat to the portion thus electrized, it
was found to be phosphorescent, and to emit a green light
nearly as strong as a portion of the mineral in its natural state,
with which it was compared. This experiment was repeated,
and always with constant results,
78 Mr. Pearsall on the Effects of
An inferior specimen of chlorophane was then heated, when
it gave out a strong light of a faint purple colour; but it
decrepitated so violently during calcination, that a piece of
sufficient size to be electrified alone could not be obtained.
The splinters were then placed in a glass tube, through
which three electrical discharges were passed, producing a deep
purple light after each discharge. They were then heated
upon platinum, when they evolved phosphoric light of dif-
ferent colours, some fragments appearing green, others yellow,
the whole finally assuming a deep purple light. These colours
were obviously distinct from those of the natural mineral, a
portion of which, heated at the same time, shewed only light
tints of purple.
Part of the same calcined specimen, but not electrified, gave
no light when heated*.
Chlorophane, whose phosphorescence had been destroyed by
an intense heat, was exposed for two days to the sun's rays
without effect ; but a single discharge again restored its phos-
phorescence.
Repeated discharges were made upon the same substance,
and it was found that the property was increased by the num-
ber and intensity of the discharges, the green light evolved by
heat being deeper and of longer duration after three, six, or
twelve discharges, than after a single discharge.
Chlorophane, which had been heated intensely, and had
been since exposed, under ordinary circumstances, to daylight
for eight months, had not acquired the least phosphorescence ;
but it gave a greenish light during the passage of the electri-
city, increasing with the strength of the discharge, and was
afterwards luminous by heat t-
A crystal of purple fluor spar, calcined at the same time,
« The mode I adopted was to heat the portions of mineral upon a platinum
capsule, covered by a watch-glass. The phosphorescence was thus rapidly pro-
duced, and easily governed by the regulated flame of a spirit-lamp. The identical
fragments were also readily submitted to repeated examinations ; and I conceive
that by using platinum instead of iron, as usually recommended, I guarded
against the introduction of matter which might have interfered in the experiments.
The calcinations were performed in a crucible at a red heat.
•J- Dr. Brewster exposed specimens to the sun's rays concentrated in the focus
of a lens, but without the slightest indication of returning phosphorescence. —
BaEwsiJSR on the Phosphorescence of Mineral*. Edin, PhU, Journal, i, 387.
Electricity upon Minerals. 79
and similarly exposed to ordinary light, did not phosphoresce
when heated, until it had been electrized, when it was faintly
luminous, with a deep-purple light.
Apatite was then experimented with, and likewise deprived
of its phosphorescent property by calcination ; but, upon
electrifying it, and applying heat, it was found to have re-
sumed the power, and evolved a lemon-coloured light, which
rendered the figure of the fragment distinctly visible.
With apatite, as well as with chlorophane, the light repro-
duced was in proportion to the discharges made. A fragment
of apatite answers better than the mineral powder.
These experiments proved, that the phosphorescent pro-
perty, when destroyed by heat, can be restored by electricity
to minerals which had thus been deprived of it.
I was therefore led to investigate how far other mineral
substances which phosphoresced by heat could have this pro-
perty increased and restored to them ; and also whether some
substances, which did not possess this property naturally,
could have it imparted to them by electric action. The
following experiments were accordingly made: —
A colourless variety of fluor spar was tried, which gave not
the least indication of light when heated ; but after six dis-
charges had been made from the Leyden jar, it was capable of
evolving a beautiful flame-coloured or orange light. In this
case, the property was conferred upon a substance which pro-
bably never possessed it previously.
The experimental results obtained with other specimens are
given in the form of a table, under the respective heads.
80
Mr. Pearsall on the Effects of
Effect when Re-heated.
Faint light.
Momentary light, but distinct. 1
Faint light.
Light faint violet-coloured, I
ending with deep purple.
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Electricity on Minerals. 81
In these, as well as in the preceding experiments, portions of
the same calcined mineral, but not electrified, were heated at
the same time ; but in no instance did the non-electrified sub-
stance evolve light.
In this table, it will be observed that Nos. 1, 2, and 3, did
not possess light in their natural state, but light was imparted
to them by electricity.
No. 4 possessed alight of a faint colour, which became whiter
as it was heated, but its conferred light ended in purple.
Those numbered from 5 to 10 had light restored to them,
which differed, however, in colour from their previous natural
phosphorescence.
11 and 12 had light given to them.
No. 13 had light restored to it.
I now proceed to some remarks on colour given to fluor
spar by electricity. In some experiments with the white
fluors which had a yellowish tinge, it was observed that, after
the powder was electrified, or when six or seven discharges
had been made through a piece of the mineral, that a difference
was perceptible between the electrified and the natural mineral,
the electrified substance having a bluish tint, whilst the other
was white. The phosphorescence was also stronger, where the
tint thus given was most obvious.
As the colour had been most decidedly given by electricity
to some portions of a crystallized mass of dark compact purple
fluor, which had been rendered colourless by heat, some white
pieces were selected and broken ; one portion had twelve dis-
charges passed over and through it, which produced a light blue
colour, very decided upon the edges and angles of the laminae,
especially toward the exterior. Both fragments were then
heated ; that which had been electrified gave a pale blue light
of short duration, and, when cold, had lost its blue tint; the
other portion evolved no light.
The fact, also, was well shewn by confining the electrical
effects to one extremity of a colourless portion ; a perceptible
tint was caused by a few discharges.
Some splinters and fragments were placed in a small heap,
inside a glass tube, open at both ends, and between the two ends
of the wires of the discharger, which were about an inch apart,
VOL. I. OCT. 1830. G
82 Mr. Pearsall on the Effects of
and likewise introduced into the tube ; after several discharges
had been made, most of the splinters had acquired a blue tint ;
when heated they evolved a strong light of a pale yellow colour.
Larger pieces electrified, assumed a blue tint, giving also a
blue light when heated ; but when these pieces were crushed
into small fragments, electrified in the tube, and then heated,
they evolved a pale yellow light, as in the preceding experi-
ment.
In some instances, however, fragments gave a light, at first
blue, afterwards changing to a straw colour ; but in every repe-
tition the colour and intensity of the light differed according
to the size of the specimen, as in the above examples.
The blue tint caused by electricity seemed to be superficial,
or nearly so; for when some coloured portions were broken,
they were colourless in the interior, but tinted upon the external
edges.
The colourless parts were not phosphorescent, while the
coloured and exterior parts were. So that it is probable that
the phosphorescent property is also conferred principally upon
the superficies, which may be the cause of the differently- sized
pieces evolving differently-coloured light.
To avoid any fallacy from the transfer of metal from the
wires, and its oxidation by the electrical explosions, experi-
ments were repeated, and the discharges were made from
platinum points, with the same resulting blue colour as before.
Other substances were then examined, which, however, pro-
duced nothing immediately bearing upon the preceding experi-
ments, excepting, however, that it was found that, by passing
twelve discharges through a diamond, it afterwards evolved a
pale blue light when heated ; it had been made red-hot previous
to electrization, but without effect.
Two other diamonds gave no light when heated, until from
twelve to twenty discharges had been made over them, when
they, also, gave a pale blue light by heat.
Diamonds probably vary in respect to this property ; for a
cut diamond gave no light, neither could any be imparted to
it by electricity; whilst, on the contrary, another diamond
was found slightly phosphorescent by heat, shewing feebly a
pale bluish light ; and this specimen, when electrified and again
heated, gave a stronger blue light than any other diamond.
Electricity upon Minerals. 83
An amethyst, sapphires, rubies, and garnets, with many
ordinary mineral substances, gave no indication either of natu-
ral or acquired phosphorescence.
In conclusion, I may be allowed to remark, that I am not
aware that the phosphorescent property has ever been restored,
or imparted, to this class of bodies, by any other means.
Note. — The consideration of other varieties of fluor, and
the duration of the effects, as well as other circumstances bear-
ing upon the preceding facts, may form the subject of a future
communication.
ON THE DEVELOPMENT OF THE SEVERAL ORGANIC
SYSTEMS OF VEGETABLES,
with reference to their Functions ; and especially on the Respiration of Plants,
as distinguished from their Digestion.
BY GILBERT T. BURNETT, ESQ.
TN no subject has indeterminateness, arising from conflicting
dogmata, prevailed in a more perplexing, in a more dis-
heartening degree than in the general philosophy of life, and
particularly in the physiology of plants. At one time even
vitality was denied to exist in them : their curious structures
and still more curious functions being all considered as merely
mechanical and chemical phenomena. When subsequently
their vitality was proved, the reaction perverted the very truth
that it established, by attributing to simpler plants the organs
of the more complex animal frame : thus we hear of the arte-
ries, the veins, and the nerves of plants ; of the uterus, the
vagina, and the testes: the roots have been declared lacteals,
and other parts placental vessels ; the leaves have been con-
sidered lungs or gills, and in their functions sometimes they
have been compared to kidneys: again, the wood has been
esteemed the osseous compages of the plant, and the pith, its
spinal marrow, or the centre of its nervous system ; which last
idea introduced the absurd doctrines of the instincts, sensation,
and perceptivity of vegetables. Nay, when not even a sem-
blance of parallelism could be either found or feigned, as was
G 2
84 Mr. Burnett on the Development
the case with the stomach and the heart ; then by a licence
still more exceptionable, analogy and affinity were confounded
with eacli other, and all deference both to structure and to
function disregarded ; for in this instance heat was regarded
as the heart, and the earth as the stomach of plants. Simi-
larity of function is often found, however, to be a far less
erring guide than similitude of external form and structure ;
the one is more general and less modified than the other, for
very diversified means may be adopted to achieve the self-
same end : thus nutrition may be performed without a mouth
to receive, teeth to chew, or even a stomach to digest the food ;
respiration may take place without either lungs or gills ; pre-
hension without either hands or claws ; and progression with-
out wings or feet.
Thus among plants, although the root may in general
be the prime organ of nutrition and the seed of reproduc-
tion, many plants are efficiently nourished and propagated
without either root or seed ; at least without those modifications
of the nutritive and reproductive systems being present, which
are ordinarily so called; the functions remaining when the
organs have disappeared, i. e., the ends being still the same,
though the means have been greatly varied. From these cir-
cumstances such plants have been called imperfect plants;
yet this has been only done, because they have been imper-
fectly considered ; and still more, because the abstract idea
formed by many phytologists of a seed or of a root, has been
rather the amplification of the idea of some particular seed or
root, e. U> to that of the patio, which, he says, in p. 91 of the work, 'has subsisted
two centuries and a-half, and will subsist as long as the world endures.'
f ' Metal de Ayuda' — Ore of a more fusible character, mixed with the less
tractable ores to assist their fusion.
J ' Plomillos' — Scoriae charged with lead.
$ « Fierros' — Slag or scum, being an unreduced mass of oxides and sulphurets,
in which those of i/w predominate,
144 Commentaries on the
some of clay. In some the smelting is performed with wood, in
others with charcoal ; in some the mouths or apertures are stopped
up, and in others left open. In some, the ore and wood are mingled
together ; in others, the wood or charcoal is not in contact with the
ore, but the flame only, whence they are called reverberatory
furnaces/
* Of the smelting of Ores. — Having made the proper mixture,
and prepared the furnaces and the machines for supplying them
with wind, the smelter must heat or anneal the furnace, if, from
being new or newly repaired, it requires it ; for, if the ore be thrown
in whilst the furnace is cold, it is apt, upon getting warm, to fly or
crack, with danger to the bystanders: and if it be moist, in the
summer, the same thing will happen, and it will explode with very
great force. During the first few hours, charcoal is first thrown in,
then a basket of slags, then one of charcoal, and so on, until it be
time to add the mixed ore. Haifa basketful of this is then thrown
in, and upon that a basket of charcoal, and so on, until the furnace
begins to work, after which, alternate basketsful of mixed ore and
charcoal are thrown in. One or two cargas of charcoal are con-
sumed for each charge, according to the nature of the ore ; some
ores requiring the furnace to be moderately filled ; others, that it
should be filled to the top. If the ore be not earthy, but clean, the
furnace may be charged freely.
' The furnace being thus arranged and brought into play, smelts
four charges in twenty-four hours, the ingots being tapped off from
time to time ; for which purpose, an aperture is made below the
bridge of the breast-pan, and the melted portion runs off into the
float. The first ingot let off, after repairing the furnace, is called
calentadura, and is smaller than the others, because the furnace
becomes coated with vitrified ore adhering to it, and care is there-
fore taken not to throw in rich ores for the calentadura. The fused
metal being let off, the bridge is stopped up, the breast-pan is
cleared out, charcoal dust is thrown into and around it, and the
furnace is again set to work. The portions which may have adhered
to it are taken off last of all, and are mixed with the ores in future
smeltings.
* After the smelting is performed, the furnace is uncharged,
which is done in the following manner. The charges of ore being
all finished, slags and charcoal alone are thrown in, until all the
smelted ore has flowed into the breast-pan, when the furnace
throws oft' a very beautiful flame. The wall of mud bricks and
everything which may have adhered to it, are then broken down
with a crow or iron bar of about twenty-five pounds weight. And
here the unfortunate smelters suffer much, during an hour of great
labour ; for the furnace is hot in the extreme, the crow is heavy,
and the incrusted matter adheres very closely. The smoke and
vapour from the slag, which are quenched by pouring water upon
them, and which are consequently carried down to the feet of the
Mining Ordinances of Spain. 145
workmen, are poisonous ; and as they drink water incessantly to
relieve their exhaustion, they lose the use of their hands and feet,
and become bloated. They are subject also to violent pains in the
stomach, occasioned by the coldness of the ore.'
After describing the mode of refining the silver, the author
proceeds to describe the operation of cold amalgamation, or
amalgamation by the patio, by which the greater part of the
gold and silver now circulating over the whole globe has been
reduced from the ore.
' Of the reduction of Ores by Quicksilver. — Nature, by exhibiting
to mankind the effect of fire in fusing the surface of mountains,
first suggested to them the idea of smelting the ores containing
lead. Nature also, by setting before them the particles of quick-
silver found amongst the ores, first guided them to the method of
mixing the harsh ores with quicksilver, salt, and water ; an opera-
tion which, although in the infancy of the discovery rude and
troublesome in practice, requiring many months to effect the reduc-
tion of the gold and silver, has now, by the devices of art, and the
lessons of experience (the best instructor in the hidden mysteries of
physics), been carried to perfection ; magistral* and various other
mixtures being employed, so that the ore may be reduced in twenty
days or under — and the process has even been completed in twenty,
four hours.
* The object of first importance, in the process of amalgamation,
is to provide a skilful amalgamator, capable of distinguishing be-
tween smelting ores, and those adapted for amalgamation ; who
can make assays, in the small way, to ascertain what the monton
will yield in gross ; who understands the proper ingredients, tem-
peratures, admixtures, and stirrings to be applied, and who can
calculate and compare the probable amount of the expenses and of
the metallic produce: for the bringing the silver to the proper
point is not to be entrusted to a mere ignorant blockhead.
4 Secondly, a due selection of the ores must be made, for the
purpose, in performing the reduction by amalgamation, of making
such mixtures as their nature may require ; and such ores as require
smelting, must be set apart for that operation.
* Third, the ore must be ground as fine as possible, that the
quicksilver may combine more readily with the silver.
* Fourth, the ore being ground, it is the practice, in some dis-
tricts, to roast such as is of a sulphureous or bituminous (?) nature,
in furnaces adapted for that purpose ; in which the criterion of being
sufficiently purified, is the ceasing to give off vapour. The same
treatment is also applied to the pyritous or resplendent ores, which,
under the influence of fire, lose their splendour, and at the same
time, get rid of their prejudicial qualities. Those which contain
* Sulphuret of copper, roasted and ground to powJer.— Trans.
VOL. I. OCT. 1830. L
140 Commentaries on the
litharge or copperas should not be roasted, until they have been
washed and thoroughly agitated in tubs of water, so as to separate
the copperas ; for unless this precaution be taken, it will be increased
in quantity by the action of the fire, instead of being driven off, and
it will have the effect of destroying the quicksilver, and preventing*
its uniting with the silver. It is sometimes proper to roast the ore
after grinding, and sometimes while in the rough. But the most
usual course, in the mining districts of New Spain, is not to roast
the ore at all, on account of the injurious effect of the operation, in
rendering it dry, in diminishing its richness, and in augmenting its
bad qualities.
* Fifth, the ore being ground, is thrown into heaps or montons,
usually of 30 quintals ; but in some places of 18 quintals: and the
montons are sometimes placed beneath a roof, but most frequently
in a well-flagged yard or patio, whence this mode of reduction is
called the reduction by the patio.
* Sixth, with each monton of 18 quintals, are mixed two barrels
of brine, from impure salt; six, eight, or ten pounds of magistral,
as the nature of the ore may require, and from ten to twelve pounds
of quicksilver. The monton thus prepared, is stirred and trodden,
which is called repasar. After two or three days, the stirring and
treading are repeated, and if it require more quicksilver, a further
charge is thrown in, and it is again stirred, until found to require
no more : and it is to be observed, that the more quicksilver it
requires the better, as a proportionate quantity of silver may be
expected.
* Seventh, the quicksilver must be added at different times, and
not be thrown in all at once, so that it may by degrees take up the
whole of the silver. The first stirrings must be performed with
softness and gentleness, lest the quicksilver should become too
minutely divided and form Us, which is the term applied when it
divides into almost imperceptible particles. From the varying na-
ture of the ore, and the diversity of circumstances which arise, no
certain rules can be laid down for the course to be pursued in
stirring in the quicksilver and magistral, and it will therefore be
found, that it is sometimes necessary to excite heat by stirring, and
at others to apply moisture. Neither is it possible to determine the
precise moment at which the montons are in a state for washing,
for though they may not make any Us of silver, nor require any
more quicksilver, yet the quicksilver may be dispersed. The only
rule is, to ascertain whether the proportion of silver taken up, cor-
responds with the result of the assay made at the commencement
of the process ; and there is no way of ascertaining this, but by
making a further trial, in a small way, whether the monton is in
want of any addition, which in such case may be supplied, or whe-
ther it is complete, in which latter case the monton may be washed.
4 Eight, the monton being ready for washing, is thrown into
wooden Vats of very large size, within each of which is contained a
Mining Ordinances of Spain. 147
mill. The mill is turned by a mule, and it is proper that it should
not always go round in the same direction, but that the motion
should be sometimes reversed : the object being-, that the Uses of
silver may fall to the bottom, and that the quicksilver contained
therein may not be lost by escaping with the slime or earthy residue,
which contains a proportion of silver, and also of quicksilver in a
minute state of division. To prevent this loss, it is therefore neces-
sary that the mixture should be kept briskly stirred in every part.
The slime being separated, the quicksilver remains at the bottom of
the vat, combined with the silver, in which state it is called amalgam.
The amalgam is taken out and placed in a linen bag, which being
suspended from the beams, the uncombined quicksilver runs out.
The part which remains in close combination is made up into small
cakes, which are formed into one large cake or pina (pine apple),
the size being adapted to the capacity of the brass cap or bell.
The latter consists of two pieces, the first of which is in the form of
a large basin, with a groove round the rim and a hole in the bottom.
On the inner part of the rim are three rests, on which is placed a
grating, made of iron bars, and upon that is set the pina or cake,
which is covered over with the cap. The cap is bell-shaped, and
fits into the groove of the vessel, which must be surrounded with
earth, and have a pan of water beneath it. The cap or bell remains
above, and is covered entirely with ignited charcoal, the heat from
which, raising the quicksilver in vapour, it finds its way into the
vessel, and passing through the hole in the bottom, is received in
the pan of water, and brought back into the state of fluid quicksilver.
Where caps of brass, copper, or iron, cannot be procured, they
must be made of the finest clay, adapted to resist the fire.
* The proportion of silver returned, depends on the quality of the
ore ; sometimes the produce of silver is equal to an eighth part of
the quicksilver mixed in with the monton, sometimes a sixth part,
and sometimes a fifth part. The quicksilver separated in a liquid
state, still contains minute particles of silver, and it is set apart to
be used in working other montons, until consumed. This is the
only part really consumed ;* for the rest is either lost by being
converted into lis in the montons, or escapes with the slime, from
the agitation of the mill, being divided into the most minute and
imperceptible particles. A quintal of quicksilver is not wholly
consumed until after it has been employed seventeen times.'
"When the ore is tolerably rich, and a more speedy return of
the silver is desired, another process is sometimes resorted to>
which is called the beneficio por cazo, or reduction by the cazo.
* In Mexico, the difference between the quantity of quicksilver employed in
the process of reduction and the quantity recovered, is arbitrarily divided into
quicksilver consumed and quicksilver lost; a quantity equal or proportionate in
wi-ijrhtto the silver obtained, being said to be cowswrwct/, and the remainder of the
dciicient quicksilver to be /wiV, — Trans,
It*
148 Commentaries on the
This process has the advantage of wasting very little quick-
silver, and is thus described : —
* Reduction by the cazo (pan). — This method of reduction affords
the most speedy means of extracting the silver. The ore being tho-
roughly ground, and a quintal being taken, the proper quantities of
salt, water, and quicksilver, are mixed in, according to the nature
of the ore. The mixture is then placed over the fire, and must be
kept constantly stirred, and the act of ebullition further assists in
keeping it in motion. It is tried from time to time, to ascertain
whether it requires any further addition of quicksilver or salt. Each
pan will reduce three charges per day. If the ore be rich, it will
often yield a marc, a marc and a half, or two marcs per quintal :
and provided the quality be not lower than six ounces, this mode of
reduction is very advantageous ; but if the produce of silver be
below that rate, it will not answer, from the great consumption of
wood, quicksilver, and salt, together with the cost of the pans and
coppers. The latter must be closely attended to, to see that there
are no chinks or cracks in the bottom, through which the quicksilver
might escape; to prevent which, they should be varnished with
several coats of lime, slag, iron, and white of egg, well beaten up
together. Barba expresses himself in highly approbatory terms of
this method of reduction, both on account of the saving in quick-
silver, and because fuel may be supplied from various trailing plants,
which abound in the Indies, and may likewise be much economised
by making one furnace heat four pans, as we have seen in several
sugar mills in the kingdom of Mexico.
4 The assays in the small way will indicate, exactly, what
quantity of silver the boiling should yield ; but this is more readily
ascertained by inspecting the substance itself, which, being taken
out with a ladle, and the slime being separated, the metal remains.
The slime is separated by washing, in vats of water, supplied from
a cistern appropriated to the purpose. This operation removes all
the earthy matter and slime ; which, when a sufficiency is collected,
are worked over in the process of reduction by cold amalgamation.
The quicksilver settles, and is found at the bottom of the vat, com-
bined with the silver. The quicksilver is then separated, in the
manner described under the head of reduction by the patio ; but
it always requires refining, never turning ont pure, like that from
the patio.1
A third method depends on the employment of sulphate of
copper, or colpa. This process, called the bcneficio por colpa,
is as follows : —
* Of the reduction by colpa (sulphate of copper.) — The plan
or sketch of the new method of reducing the silver from all
classes of ore, whether cold or warm, by means of colpa, or white
or yellow copperas, was described by Don Lorenzo Phelipe de
la Torre Barrio y Lima, a proprietor of mines in the district of
Mining Ordinances of Spain. 149
San Juan de Lucanas in Peru, and was printed at Lima in 1738,
and reprinted at Madrid in 1743 ; where a summary of the dis-
covery was likewise printed separately, in the same year, which
met with commendation from the pen of Father Feyjoo*. The
discovery consists in employing colpa, or copperas ; the goodness
of which is tried by reducing it to powder, moistening it with
water, and throwing some globules of quicksilver into it. If the
quicksilver spreads, or separates into minute particles, the colpa is
good ; and the like if the quicksilver, when placed on the colpa, and
stirred in a cup or with the finger, assumes a bluish ash colour, or
divides.
* The ore and the colpa being well ground, the latter is to be
taken in an equal proportion to the salt used. The mixture is to be
stirred, as in the ordinary process of reduction, four times a day,
and is afterwards to be charged with about two quintals more of
the colpa, and water is to be sprinkled uniformly over it. The
quicksilver is then to be stirred in, in such quantity as the nature of
the ore may require. After six days an assay is made, the stirring
being continued ; and if the ore be too warm, it is allowed to cool,
or lime is thrown in ; after which fresh charges of quicksilver are
added from time to time. The slime must be washed without
throwing in any quicksilver by way of bano^. When the quick-
silver is driven off, it will be found that a greater proportion of
silver is obtained, and that none of the quicksilver is consumed,
except such part as is lost in the stirring, or from other accidental
circumstances. This is the method pursued with the cold ores.
« ' For the warm ores it is said, that when ground, a basketful of
lime is to be thrown uniformly over them. To twenty-five quintals
of ore, ten arrobas I of salt are to be added, with a sufficient
quantity of water, and the mixture must undergo four stirrings. The
next day, the colpa, being first well prepared, is to be added, in the
proportion of one half, to the weight of salt used ; and a sufficient
quantity of water being added, the mass is to be stirred four times,
and as often on the following day. The mass being spread abroad,
another arroba of colpa is to be thrown in, distributing it uniformly,
and the mixture is to be sprinkled with water. When thus moist-
ened, the quicksilver is to be stirred in; and three da\s afler, it
must be ascertained, as in the ordinary mode of reduction, whether
the montons are cold and require more stirring, or whether they
are warm, and demand a further addition of lime.*
Other methods of reduction are likewise described, which,
being in less general use, we pass over.
When on the subject of boundaries, the author describes, at
* Cartas eruditas, torn, ii., carta 19.
f A term applied to a supplementary proportion of quicksilver, usually thrown
iu by way of softening the slime preparatory to washing. — Tnins.
£ An arroba is 2i>ibs. Spanish. — Trans.
1 50 Commentaries on the
some length, the method of mine-surveying practised inNew
Spain, and the simple instruments employed for that purpose ;
and he takes occasion to recommend the adoption of the me-
thod then practised in Europe, which he illustrates by descrip-
tions of the instruments, figures, and diagrams. (Vol. i. p. 327,
&c.) The latter method being, in principle, though not in all
its details, the same which is now pursued in the Cornish mines,
it is unnecessary to refer to it more particularly.
The various machinery employed in mining and the reduc-
tion of the ores, is also described and illustrated by faithful,
though rude figures. (Vol. ii. p. 189, &c.)
In another part of his work, the author discusses the expe-
diency of opening the quicksilver mines of New Spain, and the
probability of their admitting of being worked with advantage.
The trade in quicksilver being monopolized by the crown of
Spain, no mines of that metal were allowed to be worked, but
those of El Almaden in Old Spain, and Guancavelica in Peru,
and hence no progress was ever made in turning to advantage
the quicksilver veins of New Spain. But that there are such
veins, and that they might be worked to much advantage, is
evident from the following passages: —
' In stating above, that we have not met with any account of
mines of quicksilver having been worked in the early times after
the discovery of the kingdom of New Spain, we are to be under-
stood as referring to the sixteenth century, the era of the conquest;
but subsequent to that period, many instances may be found.
'First, some quicksilver mines were discovered in the jurisdiction
of Chilapa, at sixty leagues distance from Mexico, to the southward*.
Don Gonzalo Suarez de San Martin went over in August, 1676,
to explore these mines, with a master smith and master bricklayer,
and having set up a shed, a house, a smithy and furnaces, he had
a part of the crest of the vein blasted away on the 14th of October,
and commenced the works of San Mateo, San Joseph and Santa
Catalina, all contiguous. He began three adits at a greater depth ;
but the hardness of the ground obliged him to remove half a league
farther down, where, finding fair indications of success, he drove
the work of la Concepcion. Here also he found very good ore, in
a matrix of white spar, and drove a work, which he called los
Reyes. He then drove an adit in a cross direction, and, at the
distance of 47 varas, cut a vein of considerable size. Several
assays were made of the ores from these works, both in the large
and small way. Those from San Mateo yielded, by the minute
assay, 12 ounces of quicksilver per quintal, those from Concepcion
25 ounces, those from the cross-cut 26 ounces.
* Villa Senor, Theatro Americano, torn, i., page 178.
Mining Ordinances of Spain. 151
* The second instance was during the viceroyalty of the Duke de
la Conquista, who, in the year 1740, commissioned Don Philip
Cayetano de Medina, an alderman of Mexico, and proprietor of the
estate in which the Cerros of el Carro and el Picacho were situaU-d,
and Don Gregorio de Olloqui, an inhabitant of San Luis Potosi,
to inspect some quicksilver mines in the aforesaid Cerros, which,
according to Don Mathias de la Mota*, are in the jurisdiction of
the Sierra de Pinos, in the kingdom of New Galicia. The result of
this commission has not become known.
* The third instance is that stated above, as having occurred
in respect to these very mines of el Carro and el Picacho, in the
year 1745, when the working of a newly-discovered mine of quick-
silver was taken up by Don Fermin de Echevers, the president of
Guadalaxara. On this occasion, we know from very good authority,
that the vein was found to be rich, abundant, and easily worked,
and equal to the supply of the whole kingdom of New Spain ; and
also, that upon the result of the reduction of some of the ore, con-
ducted under the president's orders, the cost of the quicksilver
amounted to no more than 22 or 23 dollars per quintal.
* The fourth instance we shall mention, occurred previously to the
last, being in the year 1743, early in the viceroyalty of Count
Fuenclara, by whose order doctor Pedro Malo da Villavicencio,
senior judge of the royal audiency, set out for the purpose of exploring
some other quicksilver mines near Temascaltepec, the ores of which
had been subjected to several experiments and assays at Mexico, by
Don Manuel de Villegas Puente, factor of the royal stores, who
now accompanied the senior judge ; but their investigations failed
of any beneficial result, and it appears that nothing but urgent
necessity will ever induce the government to sanction the laws
permitting mines of quicksilver to be worked, like those of silver,
gold, or any other metal.
* Yet, as it is evident that there are within this kingdom mines
of quicksilver, which the crown might at any moment order to be
worked, nothing is easier than to demonstrate the expediency of
adopting the same plan here, which has succeeded so well in the
famons mines of Guancavelica in Peru f- For, first, whenever the
supply of quicksilver fails, as has happened times without number,
either in consequence of war, of losses at sea, or of the delay
attendant upon procuring it from such a distance, the reduction of
the ore in the amalgamation works is brought to a stand, the
revenue is thrown into arrear, the whole kingdom suffers, the work-
ing of the mines is interfered with, and trade receives a check. By
setting the quicksilver mines at work, all or most of these evils
would be remedied, facilities would be afforded for reducing the
silver in an expeditions manner, and the amount of the tenths, the
one per cent, and the coinage duty would be augmented.'
* Mota, MS. History of New Galicia, c. 62, n. fin.
f Solorz. Folit. lib. G; cup. -.
152 Muller on the Structure of the Eyes
In confirmation of the above, it may be added, that other
veins of quicksilver, appearing, by the analysis of Professor Del
llio, to afford ores worth working, have recently been disco-
vered in Mexico. Analyses of two specimens of the ore may
be seen in the Philosophical Magazine for August, 1828.
The pits (shafts) and adits, by the aid of which the water is
carried off from the mines, are then described.
These, with a chapter describing the operations of the
mint of Mexico (vol. ii. p. 233), a vocabulary of mining terms
(vol. ii. p. 320), and an enumeration of the mining districts of
New Spain (vol. ii. p. 332), are the principal matters falling
under the second head, which are treated by the author at
length, and with these we shall conclude the present analysis ;
passing over the legal department of the subject, which,
although forming the bulk of the work, might, we apprehend,
be less interesting to the readers of this Journal.
Anatomische Untersuchungen uber den Bau der Augen bei
den Insekten und Crustaceen vom Dr. J. Muller zu Bonn.
Mekel's Archiv fiir Anatomic und Physiologic. 1829. —
(Anatomical Investigations of the Structure of the Eyes in
Insects and Crustacea, by Dr. J. Muller, &c. &c.)
nnHE original observations of Dr. Muller, contained in his
-*- * Beitrage zur vergleichenden Physiologic des Gesicht-
sinnes, Leipzig, 1826," of which the present paper is a conti-
nuation, and which have subsequently been confirmed by G.
Treviranus, Huschke, and Straus Durckheim, have hitherto
been unnoticed in this country. They are of interest, how-
ever, not only as furnishing more correct ideas of the structure
and character of the eyes of Insects and Crustacea than those
generally received, but also as serving to remove the apparent
anomalies by which they were supposed to be separated from
the corresponding organs in vertebral animals.
It may not be superfluous to state, that, according to the
usually admitted opinions, the structure of these organs, whe-
ther simple, conglomerate, or compound, is essentially similar;
consisting in pyramidal prolongations of the optic nerve, covered
by a uniform stratum of black pigment, and externally by a
transparent cornea ; the existence of a crystalline or vitreous
humour being expressly denied. Such an organization, whilst
it presents no analogy with that of the higher animals, places
of Insects and Crustaceans Animals. 153
insuperable difficulties in the way of all attempts of explaining
the nature of the function, and naturally enough has been
quoted in support of the extravagant doctrine which refers the
seat of vision in the eyes of animals to the choroid.
The observations of Dr. Muller refer to the four different
forms of eyes as they occur in Insects and Crustacea, viz. : —
1. Simple Eyes. 2. Aggregates of Simple Eyes. 3. Com-
pound Eyes with facets on the external surface. 4. Com-
pound Eyes without facets.
1. Simple Eyes. — The eye of Scorpions and Solpugae have
all the parts of the eyes of higher animals, viz., a retina sur-
rounded by a layer of black pigment, a lens and vitreous
humour, and lastly a cornea, convex externally. The black
pigment, surrounding the cup-shaped retina, forms at the
anterior edge of the vitreous humour a projecting belt, closely
embracing the greatest posterior convexity of the lens. In
Scolopendra morsitans there are four such simple eyes on each
side of the head, of which three are circular, and the fourth
and largest, elliptical. In all there is a hard, amber-coloured,
and almost circular lens, in immediate contact with the
posterior surface of the cornea. Each lens is lodged in a cup-
shaped retina, coated externally by black pigment. In these,
as in most other simple eyes, there is either not any vitreous
humour, or it is so small as to escape notice. In other cases,
on the contrary, as Mantis religiosa, Gryllus hierogliphicus, and
the larva of Dytiscus marginalis, there is reason to suppose it
exists.
2. Aggregates of Simple Eyes. — Of this kind are the eyes of
Oniscus, Julus, Lepisma, Cymothoa, &c. In a large species
of Cymothoa, where the number of eyes thus aggregated was
about forty, Dr. Muller found as many crystalline globes or
lenses, one in contact with the posterior surface of each cornea ;
they were hard, transparent, and amber-coloured. Behind
each lens was a larger globular mass, also transparent and
amber-coloured, with a pit on its anterior surface, in which was
lodged the posterior convexity of the lens. This larger mass
was coated externally and posteriorly by a layer of black pig-
ment, and in contact at its back part with a fibre from the
common optic nerve, which probably is expanded into a cup-
shaped retina, situated between it and the stratum of pigment.
3. Compound Eyes with polygonal facets. — In many Crus-
tacea, the existence of crystalline cones or prisms between the
facets of the cornea and the fibrils of the optic nerve has long
been known. Such were described in Astacus fluviatilis, by
154 Mttller on the Structure of the Eyes
Leuwenhoek and Cavolini ; in Pagurus Bernhardus, by Swam-
merdam ; in Limulus Polyphemus, by Andre.
In Penaeus sulcatus, Dr. Miiller describes the cornea as sub-
divided into quadrangular facets, and in contact posteriorly
with a stratum of short crystalline masses, the lateral surfaces
of which are coated by a greenish opaque pigment, separating
them from each other. The crystalline columns, or prisms,
are quadrangular, perfectly transparent, very short, being about
as long again as they are wide, and in contact posteriorly with
the fibrils of the optic nerve.
In Lucanus cervus (Coleoptera), the cornea is exceedingly
thick, its facets being elongated like prisms. The crystalline
bodies are conical, the bases being almost in contact with the
cornea, whilst the apices are in contact with the extremities of
the fibrils of the optic nerve, each of which is coated externally
by a violet pigment.
A similar structure with some minor variations is also to be
found in Orthoptera, Hemiptera, Lepidoptera, Hymenoptera,
Diptera, and Neuroptera. As the general result of such obser-
vations, Dr. Miiller describes the structure of such compound
eyes as follows : — Behind the facets of the cornea is situated a
stratum of elongated transparent prisms, in close apposition to
each other, cylindrical or conical, — and allowing the transmis-
sion of light in the direction of their longitudinal axis only,
their lateral surfaces being coated with pigment. The propor-
tion between their longitudinal and transverse diameters varies
from 10 : 1, to 2 : 1. The anterior extremity, in contact with
the cornea, is sometimes smooth, sometimes rounded. The
pigment is sometimes black, as in Dytiscus, Blatta, PhalaenaB,
&c. ; at others, as in Penseus, Locusta, Gryllus, &c. yellowish-
white, greenish, &c. though still opaque.
In some few cases the transparent cones are wanting, though
their place is even here supplied by a thin transparent mem-
brane, subdivided like the cornea into facets ; e. y. in Vespa
crabro, Papilio rhamni, Libellula quadrimaculata, ./Eschna
grandis. In Meloe maialis, the cornea is studded posteriorly
with transparent projections, very convex, and almost para-
bolical.
4. Compound Eyes without facets. — In Monoculus apus
the cornea, which is continuous with the common integuments,
is smooth, and without facets ; on removing it, the surface of
the eye presents a dense aggregate of very small semicircular
elevations, which terminate posteriorly in pointed cones,
embedded in black pigment, and connected with the tuft-
of Insects and Crustaceans 4nimak< 155
shaped extremities of the optic nerve. A similar structure
probably exists in all the Monoculi, and most of the inferior
Crustacea. In the Daphniae the crystalline bodies are pear-
shaped, short, and few in number; such also is the case in
Gammarus pulex. In all, the principal peculiarities, inde-
pendent of the absence of facets on the cornea, consist in the
anterior rounded extremities of the crystalline cones, and the
manner in which they project anteriorly beyond the stratum of
pigment in which their apices are immersed ; to which, how-
ever, there are some approximations in insects. Are these
peculiarities connected with the aquatic habits of these
animals, rendering necessary a greater refractive power?
The pear-shaped masses in the Daphniae and Gammarus
pulex present an approach to the lenses of simple eyes, as
they occur (aggregated) in Oniscus, &c. The latter, however,
besides possessing a spherical lens, have a round vitreous
humour, and never the transparent conical masses. The
difference from these aggregates is still greater in Monoculus
apus, the cones being elongated, small, and numerous. Hence
it becomes necessary to discriminate the compound eyes with-
out facets, of the inferior Crustacea, as well from the compound
eyes with facets of insects and Crustacea, as from the aggregates
of simple eyes in Millipedes and Onisci.
Ueber den Ban der Augen bei Murex tritonis, Linn., vom
Dr. J. Mtiller zu Bonn. (Meckel's Archiv, No. 3, 1829.
On the Structure of the Eyes in Murex tritonis.)
fTVHE black points at the extremities of one of the pairs of
feelers in Helix pomatia, were long ago described by Swam-
merdam as eyes, in which he recognised an aqueous humour
and a crystalline lens. Subsequently, Stiebel ( ' Meckel's
Archiv,' b. 5) examined the same parts in Helix pomatia
and Cyclostoma viviparum, and found in them a choroid, an
iris, and a crystalline. As the true nature of these supposed
eyes of gasteropodous mollusca was, however, still by many
considered problematical, Dr. Mulier availed himself of an
opportunity of deciding the question by examining them in
Murex tritonis.
They are here placed at the outer side of the feeler, on a
small eminence near its root, the axis of the organ being in the
same direction as that of the feeler itself. The surface of the
eye is convex, and surrounded by a prominent ridge formed
156 Miiller on the Eye in Murex Tritonis.
by the substance of the feeler. The eye itself is easily sepa-
rable from the surrounding substance, and is then seen as a
blackish sphere, with its greatest diameter in the longitudinal
direction. A thin transparent lamella, continuous with the
substance of the feeler, is expanded in front of the globe of the
eye. This cornea, as it may be considered, is separated from
the globe by a space extending over its anterior third, which
in the recent state is probably occupied by a fluid (aqueous
humour).
The posterior part of the globe, embedded in the substance
of the feeler, is formed by a greyish-black membrane (choroid),
which at its anterior part forms a narrow circular belt of a
darker colour (iris), perforated in its centre by a circular
pupil. The external margin of the cornea reaches somewhat
farther back than the outer edge of the iris.
The optic nerve, which is a branch of the nerve running
in the axis of the feeler, perforates the posterior part of the
cup formed by the choroid, and probably expands on its inner
surface into a retina, of which some imperfect traces were
visible. The inner surface of the choroid is perfectly black ;
its cavity is almost completely occupied by a firm, round,
amber-coloured mass, similar to those found in the eyes of
spiders, and representing either a crystalline lens or vitreous
humour.
As the most essential parts of an eye are here present,
and of comparatively large size, we are warranted in supposing
that there must be a corresponding power of vision. Experi-
mental observations on this point are the more desirable, as
in Helix and Cyclostoma, where there is a similar organization,
the animals appear not to see, or at least not distinguish
objects.
( 157 )
FOREIGN AND MISCELLANEOUS INTELLIGENCE.
§ I.— MECHANICAL SCIENCE.
1. RESISTANCE OPPOSED TO WATER MOVING IN PIPES. —
(U Aubuisson.)
NOTWITHSTANDING the endeavours made to deduce formulae from ex-
periments on the passage of water through tubes, so as to assist and
guide the engineer in laying down pipes to supply manufactories
or towns, yet frequent mistakes have occurred: thus at Paris, at the
Fontaine des Innocens, only two-thirds of the water calculated upon
were obtained ; whilst, in the faubourg St. Victor, only the half of that
expected issued from the pipes. These differences appear to result
from experiments made on too small a scale, or with apertures dis-
proportionate to the areas of the tubes ; for the results of practice
come sufficiently near to the formulae of MM. Prony and Eytel-
wein, when the velocity of motion in a pipe was small in conse-
quence of a contracted aperture made in a plate of metal being used.
When the contracting plate was altogether removed, then the pro-
duct in water was a fourth or third less than that given by the
formulae, from which M. D'Aubuisson concludes that the resistance
increases with the velocity in a greater ratio than that given to it in
the calculations; where it is supposed to increase proportionably as
v9 + m v, m being nearly equal to 0.055, and v representing the
mean velocity.
In consequence of the arrangement and state of the water-pipes
at Toulouse, some large and accurate experiments have been made
there by MM. Castel and D'Aubuisson, in systems of pipes of 4.7
inches and 10.63 inches in diameter, and 1434 and 1986 feet in
length. In these experiments the quantity of water passed and the
pressure were varied; the results were noted, and also calculated
by the formulae, so as to deduce the loss of pressure due to the
resistance of the pipes: that by calculation came out 27., 25., 32.7,
and 31.7 per cent, below the result of experiment. As the two
latter were the principal experiments, it is concluded that, generally,
calculation gives the resistance nearly one-third less than what is
obtained by actual and careful practice *.
2. ON THE RESISTANCE OF LEAD TO PRESSURE, AND ON THE
INFLUENCE OF A SMALL QUANTITY OF OXIDE UPON ITS
HARDNESS.
The recent experiments of Mr. Bevan on the compression of lead f,
and his proposal of applying balls of that metal to estimate the force
of presses, screws, &c., must be well known to English readers.
* Annales de Chimie, xliii. p. 224.
f Quarterly Journal of Science, N. S., vol. vi.,p. 392.
158 Foreign and Miscellaneous Intelligence.
A similar investigation has been entered into by M.Coriolis, which,
however, is much more refined as regards those circumstances
that enable the lead to resist the force applied.
The points at first under investigation by the latter philosopher
were temperature, time, impact, and state of the surfaces between
which the lead was confined. The pieces of lead were cylinders 24
millimetres in diameter, and 19 in height ; weighing each from 100
to 101 grammes. The arbitrary scale of measurement used gave
680 divisions for the 19 millimetres of height. The lead was
pressed between two plates of iron in a kind of box, allowing lateral
enlargement as the pressure was exerted, and the measurements of
thickness were taken by means rendering the estimation very
delicate.
To remove any irregularity resulting from differences in the times
of pressure, it was in all ordinary cases limited to an exact minute.
To ascertain the effect of impact, two pieces, which had been pressed
equally, were then re-pressed, the one for two minutes, the other
also for two minutes, but at eight different operations. On making
thus the effect of impact eight times as much in one case as in the
other, still the whole difference was only 19 divisions, which, di-
vided amongst the extra 7 impacts, gives only about 3 divisions for
each. As to the original temperature, its effect amounts to little or
nothing ; for when the cylinders were purposely cooled down, the
mere effect of compression evolved so much heat that they could
scarcely be touched, and this heat soon overpowered the original
difference : experimentally no sensible difference was produced. In
reference to the influence exerted by the state of the surfaces be-
tween which the lead was pressed, this also proved to be insensible.
In the experiments the results are always expressed by the num-
ber of divisions to which the thickness of the lead has been reduced
from the original standard thickness of 680 parts ; and in this ab-
stract we shall only give the mean results. Under the following
pressures the ordinary lead used in mints was reduced to the ex-
pressed thickness.
Kilogrammes . 1500 1824 ]950 3175
Thickness . . 463 336 337 296
When this lead was re-fused and cast, it was found to have increased
so much in hardness, as with 1500 kilogrammes to give 490
degrees.
Lead was then reduced from the carbonate, and tried after being
fused and cast once, twice, thrice, &c., care being taken as much
as possible to prevent oxidation by the use of tallow, charcoal, &c,,
upon the surface. By the pressure of 1950 kilogrammes it was,
after the first fusion, reduced to 333 degrees ; after the second to
351 ; after the third, to 398, always setting off from the standard
thickness of 680.
This effect was referred to a small quantity of oxide introduced
Mechanical Science. 150
into the lead at each time of pouring. To ascertain the truth of
this opinion, a stopcock was attached to the bottom of the melting
vessel so that the lead could be drawn off without any contact with
the atmosphere, the surface above being covered all the time with
a thick layer of charcoal powder. Then the former experiments
being repeated, it was found that lead, after the first fusion, was
reduced to 303, less than on any former occasion ; after a second,
to 311 ; and, after a third, to 301 ; so that now no repetition effusion
produced any effect. Some of the lead was also cast in this way,
being- first raised to a cherry-red heat, and others only to the lowest
point necessary for liquefaction. The effects were the same in both :
no influence had been exerted over the hardness of the metal, and
the changes which usually occur are due to a little oxide introduced.
In experiments upon the influence of time it was found that, after
a minute had elapsed, the effect of time was masked by the general
effect of the metal, and nearly hidden. For a charge of 1950 kilo-
grammes the compressions were as follows : —
Time . . 30" 45" 60" 75" 90" 120"
Thickness 365 331 322 321 319 313
So that here, after a minute, 10" produced an effect of only 2 de-
grees upon the scale. Still it was found the effect did proceed ;
for with a charge of 1760 kilogrammes the effect was as follows : —
Time ... 1 minute 1 hour 24 hours
Thickness 317 245 223
So that, after 24 hours, the lead still continued to give way.
The most important conclusion from these experiments is, that
lead fused and cast in the open air is of variable hardness, and that
to obtain it with its true and constant power of resistance, it must
be cast out of contact of air, and drawn off from the bottom of the
mass *.
3. ON THE POWER OF HORSES. — ( B. Bevan, Esq.)
The following experimental data are from a letter written by Mr.
Bevan to the Editors of the Philosophical Magazine.
" In the period from 1S03 to 1809 I had the opportunity of
ascertaining correctly the mean force exerted by good horses in
drawing a plough ; having had the superintendence of the experi-
ments on that head at the various ploughing matches both at Wo-
burn and Ashridge, under the patronage of the Duke of Bedford
and the Earl of Bridgewater. I find among my memoranda the
result of eight ploughing matches, at which there were seldom
fewer than seven teams as competitors for the various prizes,
* Annales dc Chiinic, xliv. p, 103,
100 Foreign and Miscellaneous Intelligence.
Lbs.
The first result is from the mean force of each horse in six
teams of two horses each team, upon light sandy soil . =156
The second result is from seven teams of two horses each
team, upon loamy ground, near Great Berkhampstead . rr 154
The third result is from six teams of four horses each team,
with old Hertfordshire ploughs = 1 27
The fourth result is from seven teams of four horses each team,
upon strong stony land (improved ploughs) = 167
The fifth result is from seven teams of four horses each team,
upon strong stony land (old Hertfordshire ploughs) . . = 193
The sixth result is from seven teams of two horses each team,
upon light loam = 177
The seventh result is from five teams of two horses each, upon
light sandy land = 170
The eighth result is from seven teams of two horses each team,
upon sandy land = 160
" The mean force exerted by each horse from fifty-two teams, or
one hundred and forty-four horses, = 163 pounds each horse; and
although the speed was not particularly entered, it could not be less
than at the rate of two miles and a half per hour.
" As these experiments were fairly made, and by horses of the
common breed used by farmers, and upon ploughs from various
counties, these numbers may be considered as a pretty accurate
measure of the force actually exerted by horses at plough, and which
they are able to do without injury for many weeks ; but it should
be remembered that if these horses had been put out of their usual
walking pace, the result would have been very different. The mean
power of the draught-horse, deduced from the above-mentioned ex-
periments, exceeds the calculated power from the highest formula
of Mr. Leslie;" — which is as follows: (15 — v)* =: pounds avoir-
dupois for the power of traction of a strong horse, and (12 — v)2
= pounds traction of the ordinary horse, v — velocity in miles per
hour*.
4. ON THE CHANGE OF VOLUME OCCURRING WHEN BODIES
COMBINE TOGETHER.
An experimental examination of the change of density induced by
combination has been undertaken by M. P. Boullay, with a view to
ascertain whether any general law could be deduced by which might
be obtained an insight into the density of substances generally when
in combination. His first care was to obtain the specific gravities
of many bodies, simple and compound, to a high degree of accuracy,
and in this respect every precaution appears to have been taken.
Then comes the point principally under discussion: either the spe-
* Phil. Mag., N. S., viii. p. 22.
Mechanical Science. 161
cific gravity of a compound is the sum of the specific gravities of its
elements, or it is different in consequence of contraction or dilata-
tion. In by far the greater number of cases it proves to be different :
thus, in the sulphurets of mercury, lead, arsenic, antimony, tin, and
iron, the specific gravity is increased; in the iodide of potassium it
is also increased ; in those of silver, mercury, and lead, it is dimi-
nished. Then endeavouring to determine whether the contraction
was the same for bodies having similar atomic composition, no
analogy was found ; so that, though many sulphurets and iodides
have been examined carefully, nothing can be deduced from them
relative to other sulphurets and iodides : even constancy of contrac-
tion or expansion cannot be deduced, for the iodides present cases
of both.
These results on the sulphurets and iodides appear to M. Boullay
important, not only as adding facts to our knowledge, but as marking
and destroying an error into which many philosophers, occupied with
the same question, have fallen. They have endeavoured to deter-
mine the specific gravity of bodies brought to the same condition,
(the solid state, for instance,) but have been stopped by those sub-
stances which cannot be brought into that form. Assuming the
hypothesis, however, that in the union of two bodies in the solid
state there was neither expansion nor contraction, or else that the
negative element only was altered, they have thought themselves
justified in deducing from the specific gravity of a binary compound
and one of its elements, the specific gravity of the other : thus the
densities of oxygen and chlorine have been calculated from the
metallic oxides and chlorides. This assumption is entirely done
away by the facts quoted.
Even admitting for a moment the hypothesis as good, calculation
from it proves its own fallacy : thus the density of oxygen derived
in this way from the oxides varies from 1.25 to 5.88, which, without
experiment, would prove great modifications by expansion and con-
traction. The chlorides gave still more striking results for chlorine ;
and from the specific gravity of the chloride of potassium it would
appear that a volume of this binary compound contains more than
its volume of metal only, indicating an enormous contraction between
that substance arid the chlorine*.
5. APPARENT HYDROSTATIC ANOMALY WITH LAUREL-OIL.
Dr. Hancock has remarked a curious apparent anomaly in the
hydrostatic pressure of two fluids, the lighter of which, upon mix-
ture, passed to the bottom, and the heavier to the top. One of the
fluids is laurel-oil ; the other a mixture of pure ether (i. e. free from
alcohol) and proof spirit in equal proportions, or with a slight excess
of ether. Such a mixture is lighter than the essential oil, but when
the latter is poured upon the former it floats, and indeed whichever
* Annales de Chimie, xliii. 266.
VOL. I. OCT. 1830. M
162 Foreign and Miscellaneous Intelligence.
is added last the same effect takes place ; nor does the ultimate state
of things differ, whether the mixture be made gently, or violent
agitation be given to it.
Dr. Hancock concludes that these seemingly strange appearances
result from the strong affinity of the essential oil for ether, by which
it attracts it from the mixture with alcohol, combines with it, and so
forms a mixture essentially lighter than the ether and spirit. He
found, by trial, that though the essential oil would not mix with
ether if at all adulterated, that with pure ether it dissolves in ever^
proportion.
A remarkable circulating motion was also observed when
laurel-oil and alcohol were brought together. * Take a phial of the
laurel-oil, and drop into it at different intervals some rectified
spirits of wine, when the most interesting results will be observed
to ensue — a circulation, presently commencing, of globules of
alcohol up and down through the oil, which will last for many
hours or for days, (how long is unknown.) A revolving or circu-
lating motion also appears in the oil, carrying the alcoholic globules
through a series of mutual attractions and repulsions ; the round
bodies moving freely through the fluid, turning short in a small
eccentric curve at each extremity of their course, passing each other
rapidly without touching, but after a time they seem to acquire a
density approximating to that of the lower stratum, which appears
to be an aqueous portion separated by the ethereal oil from the
alcohol ; and this assimilation taking place, the globules, after per
forming many revolutions, will fall flat upon the surface and unite
with the lower or watery stratum. This experiment was performed
with a small phial : perhaps a larger one would render the result
more perspicuous*.'
6. ON THE QUANTITY OF LIGHT REFLECTED BY METALLIC
SPECULA AT DIFFERENT ANGLES OF INCIDENCE. — (R.
Potter, Esq.)
A paper upon this subject has been read to the Royal Society by
Mr. Potter, in which he shews some curious departures in fact from
generally received opinions. Sir Isaac Newton has stated, that
metallic specula, in common with all other substances, reflect light
most copiously when incident most obliquely. Some experiments
made by the author, with specula of his own construction, having
raised doubts in his mind as to the accuracy of the prevailing opinion
on this subject, which accords with that of Newton and of Bouguer,
he instituted a more exact inquiry into the proportions of incident
and reflected light from specula at various angles of incidence. He
used for this purpose a photometer resembling that of Bouguer, and
consisting of an upright screen with a square aperture, across which
a piece of thin tissue paper was extended, destined to receive on one
compartment the reflected light from one lamp, and on another
* Brewster's Journal, 1830, 48, 51.
Mechanical Science. 163
compartment the direct light from another lamp, employed as a
standard of comparison. By adjusting the respective distances of
the lamps, the lights on the paper were rendered sensibly equal in
point of intensity, the equality being judged of by the eye viewing
them from the other side. The measurements were taken alternately,
first one of the direct, and then one of the reflected lights, until a
sufficient number of uniform results were obtained. The author,
after taking every precaution that occurred for insuring accuracy,
invariably found that the proportion of light reflected from metallic
substances, instead of increasing, diminished in pretty regular gra-
dation, as the angle of incidence was augmented. Thus, in the first
experiment, when the angle of incidence was 20°, the proportion of
the reflected to the incident light was as 69.45 to 100 ; at 40° it
was 66.79 ; and at 60° it was reduced to 64.91. Some irregula-
rities occurred in the series of results deduced from different sets of
experiments, arising partly from the variableness of the light given
out by the lamps, and partly from the difficulty of preserving the
metallic surface in the highest state of lustre which it has when
newly polished. The author combats the opinion, that the quan-
tities of light which metals are capable of reflecting when polished,
are in the ratio of their densities ; and finds that in those metals
which were the subjects of his experiments, the quantities of light
absorbed or lost by reflection at incidences nearly perpendicular are
almost exactly in the ratio of their specific heats*.
7. ON THE APPARENT PROJECTION OP STARS UPON THE
MOON'S DISK.
The attention of astronomers has lately been called in a particular
manner, by Sir James South, to the extraordinary effect which had
often previously been observed of the apparent projection of the stars
upon the moon at the time of occultation. The star, on coming up
to the moon, in place of disappearing instantly behind its edge,
appears (for several seconds occasionally) to advance a short space
on to or before its disk, and then disappear. This effect does not
always happen with the same occultation ; some persons see it-
others do not; it happens for variable periods of time, and upon
both the dark and bright limb of the moon, though most frequently
upon the latter^
A very curious letter upon this subject has been written by M.
Gergonne to the editor of the Bibliotheque U?u'versellet in which he
describes an example of this illusion, of rather an early date.
* Before 1789, or rather in 1786, I cannot say at what season, as I
was coming after mid-day from the College of Nancy, where I
studied, (it consequently was about a quarter to five o'clock,)
I found about a dozen men and women in a group, at the bottom
of the Rue St. Michel, very nearly in front of an Eglise de Penitens
* Phil. Mag., N, S., viii, 60.
164 Foreign and Miscellaneous Intelligence.
which has disappeared in the revolution — their eyes being atten-
tively fixed on the sky. Inquiring1 of one of them what was the
matter, he pointed with his finger to the object of their attention,
at the same time saying, " A star on the moon !" and, in fact, I saw
a star of considerable brilliancy on the edge of the enlightened part
of the moon's disk. According to the position of the star relative
to the sun, which was still far from setting, this should have hap-
pened in the spring or autumn, near the first quarter. I remained
some instants considering the phenomenon, which gradually dis-
appeared. I cannot now say positively whether the star disappeared
behind the moon, or whether it separated from it.
* Although I was not at that time much versed in astronomy, I
did not doubt that the supposed star was Venus, which I had some-
times observed in full daylight ; and as I also knew that Venus was
placed in the heavens as to us far beyond the moon, the phenomenon
appeared very surprising to me ; and hence, doubtless, the reason
why I have preserved the recollection of it.
* This particular fact would have nothing more remarkable than
many others which had been cited, if it did not establish, i. That
the phenomenon may be seen in full day-light; ii. That it may be
well observed with the naked eye, and that, consequently, the ex-
plication is not to be found in any action of the telescopes ; iii. That
it does not depend upon such a condition of the eye as, being purely
accidental or exclusively proper to such and such persons, would
prevent its uniformly affecting several persons collected together
accidentally ; iv. That its duration may much exceed that of some
seconds, for on this occasion it certainly lasted above a minute.
Such a prolonged effect should necessarily happen each time that
the motion of the occulted star is, with respect to the moon, nearly
a tangent to its disk ; and if I had at hand the volumes of the
Connaissance des Terns for that time, I should, without doubt, find
that the occultation which I have described, and which I should
then be able to refer precisely to the year and day, would be in this
condition. It is also to occultation of this kind that the preference
should be given, that leisure may be obtained for the correct ob-
servation of the appearances.' This letter is signed J. D. Gergonne,
editor of the Annales des Mathematiques, and in a note to it, it is
stated that in the Connaissance des Terns for 1788, p. 43, may be
found mention of an occultation of Venus on the 9th April, 1788,
about three hours fifty-four minutes afternoon, which might be seen
from many parts of the earth, but not at Paris*.
8. ON THE PRODUCTION OF COLOURED BANDS BY PLANE
MIRRORS.
If a person stand before a silvered mirror and observe the re-
flected image of a candle, he will see at its sides several verv
* Bib. Univ., 1830, 345.
Mechanical Science. 165
apparent coloured bands. The light may be held a few inches
before the eye, and so that the incident and reflected rays may
make but a small angle. This experiment is due to Mr. Whewell
of Cambridge ; but M. Quetelet, on repeating it, found that it was
not constantly produced, and that the necessary condition was the
presence of a slight film of vapour on the glass*. To make the
experiment it is sufficient to breathe upon a cold mirror at the place
where the image of the candle is to be reflected.
M. Quetelet has found that the experiment succeeds as well
when the mirror is not silvered ; even a piece of crown glass will
do ; but, from its irregularities, the bands are not so distinct. Day-
light does not interfere with the observation. A drop of oil behind
the glass makes the colours disappear. A line from the image of
the eye to the image of the light is always perpendicular to the
direction of these coloured lines. The bands affect the form of
curved lines, which, in certain cases, degenerate into straight linesf.
They do not extend far beyond the image of the light. The colours
proceeding from the light are bluish-green, yellow, red ; bluish-
green, yellow, red, &c. Other circumstances being the same, the
bands are larger as the observer is farther from the mirror, as the
ligfit is nearer to the eye, and in fact as the angle between the inci-
dent and the reflected rays is smaller.
This phenomenon does not appear to be related to that which
Newton observed with concave mirrors. It appears, as to the
colours, to have more connexion with the effect observed when the
sun or a light is seen through a transparent plate upon which has
been spread a very fine powder.
The breath forms but a transient haze ; but M. Quetelet has
found an easy mode of rendering the preparatory state of the glass
permanent. It consists in extending a very thin regular film of
fatty matter, as oil or tallow, over the glass ; a soft cloth is to be
pressed lightly or dabbed over the whole surface of the film to
destroy the parallel lines otherwise existing, and then the effect is
obtained as well as with the breathj.
9. SIZE FOR ILLUMINATORS, ARTISTS, &c.
.Four ounces of Flanders glue and four ounces of white soap are to
be dissolved on the fire in a pint of water, two ounces of powdered
alum added, the whole stirred and left to cool. It is to be spread
cold with a sponge or pencil on the paper to be prepared, and is
much used by those who have to colour unsized paper, as artists,
topographers, &c.§
* Many mirrors produce the effect without the film, in consequence of a
slight granulation left upon the surface of the glass by the manufacturer. — Ed.
f We have never seen the bands in a flat piece of glass otherwise but straight.
— -Ed,
I Bull. Univ., A. xiii., 190, 192. § Ibid. E. xiv. 344.
166 Foreign and Miscellaneous Intelligence.
§ II.— CHEMICAL SCIENCE.
1. GALVANIC CURRENTS DURING THE DECOMPOSITION OF
WATER.
The following description is from the personal observation of Pro-
fessor Silliman. * In the decomposition of water by the galvanic
power, two tubes being filled with water, and inverted in a vessel
filled with that fluid, their orifices being about one inch apart and
the connexion established through the fluid by slips of platina, I
had recently the satisfaction of observing distinctly the currents of
gas as they took their departure to their respective poles. It has
been a problem, whether the water is decomposed under one tube,
or the other tube, or at some intermediate point; but, in the expe-
riment referred to, ocular demonstration was exhibited, that the
decomposition took place simultaneously, under both tubes, and not
at any intermediate point. This appeared from the fact, that under
each tube a current of gas rose vertically from the platina slip, and
collected in the top of the tube, while another current shot off
laterally and took up its march towards the opposite pole beneath
the contiguous tube : as this process was going on at the same
time under both tubes, it follows that there were opposite currents
of gas, but they occasioned less mutual disturbance than might
have been supposed ; because the levity of the hydrogen and the
gravity of the oxygen determined them to pass each other at dif-
ferent levels, and although many bubbles were buoyed up in the
passage, and made their escape, and were lost by passing through
the water intermediate between the two tubes, a large part of the
gases was collected in the respective tubes. The process was con-
tinued for several hours with a large battery, and the currents were
palpable to all the bystanders. With a magriifying-glass the ap-
pearance was beautiful, and nothing can exhibit more decisively the
all-dominant power of the galvanic influence in causing even gaseous
elements to separate at different points, and to pass horizontally,
in opposition, through at least two inches of water, until they
arrived at the poles by which they were respectively attracted : but,
on examining the gases in the two tubes, so far from finding the
oxygen gas in the one and the hydrogen in the other, there was
found in both a highly explosive mixture, which gave a very sharp
report when a flame was applied ; and in fact the result was pre-
cisely the same as when the two tubes, standing in different vessels
and furnished with metallic caps and depending platina wires, to
connect them with the slips of the same metal below, are joined by
a good conductor touching the caps.
Did the strong mechanical conflict of the two opposite currents
cause the gases to be intermingled and thus to be in part carried
into the stream? or did a portion of each gas fail to be expelled from
the tube by the attractions and repulsions, and thus rise by mere
Chemical Science, 167
levity, to mingle with the gas appropriate to each particular
pole * ?
We can by no means consider Professor Silliman's account as at all
altering the state of our knowledge relative to where the decompo-
sition of water occurs, between or at the voltaic poles. The Pro-
fessor seems to imply that it takes place at both poles, quoting the
two currents from each pole as the proof; but there is no proof that
the two currents were not of the same gas, i.e., both oxygen at the
positive and both hydrogen at the negative pole ; and, in fact, that
is the only way of accounting for the mixture of both gases in
both receiving tubes. There is great reason to believe that the
arrangement of the gas at each pole into two currents, one internal
and the other external to the receiving tube, was a mere conse-
quence of the descending water carrying off the smaller bubbles
with it.— Ed.
2. POWER OF METALLIC RODS, OR WIRES, TO DECOMPOSE
WATER, AFTER THEIR CONNEXION WITH THE GALVANIC
PILE is BROKEN. — (Berzelius.)
In the experiments which I undertook in 1806, 7, in company with
Mr. Hisinger, we had found that rods of metal which were em-
ployed to decompose water by means of the galvanic pile, continued
to develope gas after their connexion with the pile had ceased, a
circumstance which seemed to indicate a continuance of electrical
state, though these rods shewed no action upon any other portion
of liquid, even of the same kind, than that in which they had been
placed during their contact with the pile. This observation, which
I had almost forgotten, has been lately confirmed by Pfaff, who has
also added to it several others of a similar kind. We might suppose
such effects to be produced by a residual polarity, both in the liquid
and the metal, shewing itself, as long as it continues, by a continua-
tion of chemical action ; but some of Pfaff 's experiments seem to
oppose this idea, for he found that the addition of ammonia to the
liquid, by which all its internal polarity was destroyed, did not
deprive the wires of their effect. The metals which acquire this
property in the highest degree are iron and zinc, next to which
is gold. He attempts to explain the phenomenon, by supposing
that the continued passage of the electrical stream had brought the
elements of the water nearer to a state of separation, so that a very
slight influence was sufficient to destroy their union. It must be
confessed, however, that we cannot at present advance a satisfactory
explanation!.
3. ON PYROPHOSPHORIC ACID AND THE PYROPHOSPHATES.
Mr. Clarke first pointed out the singular change induced upon the
phosphates by calcination, and, conceiving the acid was changed
in its nature, gave it in its new condition the name of Pyrophos-
* Silliman's Journ., xviii. 199. f Berzelius, Arsberattelse, 1829, p. 33.
168 Foreign and Miscellaneous Intelligence.
phoric acid. Gay-Lussac then gave further light on the subject,
and now M. Stromeyer has published an investigation of the sub-
ject, which adds Very much to what was before known.
M. Stromeyer first compares the two salts of silver, namely, the
phosphate and pyrosphosphate, as those compounds which most
strikingly exhibit the new characters impressed on the acid. Both
these salts are pulverulent, and, when well dried, anhydrous ; the
first is yellow, the second white ; the first has a specific gravity of
7.321, the second of 5.306. The first fuses with great difficulty,
requiring a very high temperature, and cools into a yellow mass.
The second fuses beneath a red heat into a brown liquid, which, by
cooling, becomes a colourless, crystalline mass. Both salts are
insoluble in water, both dissolve in nitric and sulphuric acid, and
are precipitated unchanged ; but when the pyrophosphate is heated
in solution, it becomes ordinary phosphate. Muriatic acid decom-
poses it, but without changing the peculiar character of the acid.
All the metallic pyrophosphates, boiled with phosphate of soda,
become phosphates, and form pyrophosphates of soda — the reverse
does not take place. Hence pyrophosphoric acid should be placed
after phosphoric acid in chemical affinity ; and this alone establishes
an important distinction between the two. Most of the pyrophosphates
recently precipitated dissolve freely in the solution of pyrophosphate
of soda. The same effect does not happen with the phosphates and
phosphate of soda.
Hence, that a great difference exists between the phosphoric and
the pyrophosphoric acid is evident, although the latter is obtained
by calcining the former, or by burning phosphorus in oxygen ; still
there are plenty of reasons why the difference should not be due to
either an excess or deficiency of oxygenation in this respect. M.
Stromeyer shews that both are alike ; neither does it depend upon
more or less water combined, for the two salts of silver are both
anhydrous, and yet their properties are distinct.
M. Stromeyer determined the composition of these two salts,
and, by various modes of experimenting, proved that they contained
different proportions of acid and base. The result of all his experi-
ments was, that the proportions per cent, were as follows : —
Oxide of Silver. Acid.
In the phosphate . . 83.454 . 16.545
pyrophosphate . 75.390 . 24.610
for equal quantities of acid, therefore, the quantity of oxide of silver
in the two salts is as 3 : 5. This great difference in saturating
power is the cause why, when a neutral phosphate of soda is calcined,
it becomes strongly alkaline, for the phosphoric acid present, by be-
coming pyrophosphoric acid, loses two-fifths of its neutralising power,
and yet this extraordinary effect happens without any loss of acid,
or any change in the quantity of its constituents. The whole dif-
ference depends upon the manner in which the elements combine,
and it is one more added to the very few decisive cases previously
known, in which the mere mode of combination, and that too in a
Chemical Science. 169
binary compound, produces such differences of properties as to con-
stitute the products real and distinct substances*.
4. PRODUCTION OP HYDROCYANIC (PRUSSIC) ACID UNDER
UNCOMMON CIRCUMSTANCES. — (A. A. Hayes.)
Wishing to decompose some nitric acid containing about one-third
its weight of dry acid, it was subjected to distillation with one-third
of its weight of raw sugar; the distillation was attended by the
production of vapours of nitrous and hyponitrous acids, as is usual
in the decomposition of nitric acid. The fluid in the receiver was
slightly acid, it was therefore returned to the retort still containing
the residue of the first operation, and gentle heat applied ; the
strong and peculiar odour of hydrocyanic acid was developed, in
such a quantity as to render the atmosphere of a small room irre-
spirable. After cooling the apparatus and decanting the distilled
fluid, a few drops of ammonia were added, and the alkaline fluid,
mixed with a solution of proto-sulphate of iron, and a few drops of
acid, deposited a bulky precipitate, which, on exposure, became of
a fine blue colour. — Rosebury Laboratory, March, 16th, 1830 f.
5. ACTION OF CHLORINE ON CARBURETTED HYDROGEN. —
A memoir upon the action of chlorine on carburetted hydrogen,
consisting of single proportionals of carbon and hydrogen, has been
read by M. Morin to the Societe de Physique, &c., of Geneva,
of which the following is a brief abstract. The investigation was
rendered necessary in consequence of the conflicting statements put
forth by different philosophers of the nature, composition, and pro-
duction of the resulting substance.
When chlorine and olefiant gas are brought together over water,
a compound sometimes called chloric ether, or hydrocarburet of
chlorine, is formed, which was analysed several years since by MM.
Robiquet and Colin: they concluded, from all their experiments,
that it consisted of equal volumes of chlorine and olefiant gas com-
bined together, and in fact, it was well ascertained, that in these
proportions the substance was abundantly produced, and the gases
disappeared.
M. Morin analysed it by passing its vapour through a tube heated
to dull redness : carbon was left in the tube and a gaseous mixture
obtained, containing two volumes of muriatic acid gas, and one
volume of a peculiar carburetted hydrogen, containing twice its
volume of hydrogen, in combination with 0.6 of a volume (as the
hypothesists say) of the vapour of carbon ; 3.7 parts of the hydro-
carburet of chlorine were used, and, according to the received opi-
nion of composition, a fourth more of muriatic acid, and a third less
of the carburetted hydrogen gases ought to have been obtained.
Hence it appeared, that a very considerable part of the chlorine
* Ann. de Chim., xliii. 364. f Silliman's Journal, xviii. 201 .
170 Foreign and Miscellaneous Intelligence.
had somehow disappeared. M. Morin found this in the water over
which the compound had originally been formed ; for although both
gases may have been well purified, this water always becomes strongly
acid, and in fact, being saturated with bi-carbonate of potassa, eva-
porated to dryness and ignited, the chloride of potassium produced
was found to contain half the chlorine which had been employed
in forming the oily fluid.
Hence the true theory of action is as follows : four atoms of car-
buretted hydrogen being acted upon by two atoms of chlorine
(equal volumes), one of the former gave its hydrogen to one of the
latter, to form one of muriatic acid, and its carbon to the other
atom of chlorine, to form an atom of proto-chloride of carbon.
This atom of proto-chloride, combined with the remaining three of
carburetted hydrogen, forms the chloric ether * ; and upon consi-
deration it will be found, that such a compound would give by
decomposition the proportion and kind of gases before stated to
occur.
Action of Chlorine on Alcohol. — As alcohol and ether may be
considered as hydrates of carburetted hydrogen, M. Morin then
closely investigated the effect of chlorine upon them. In the
alcohol experiment, the chlorine being disengaged in a matrass,
then passed through a vessel containing chloride of lime, next
through that containing the alcohol, next to this was a vessel
containing water, and ultimately a fourth with a solution of chlo-
ride of lime ; the third vessel was to absorb any muriatic acid
formed, and the fourth to saturate any carbonic acid which might be
disengaged. When the chlorine was passed very slowly, and the
alcohol was very pure, the whole of the gas was absorbed, and a
greenish oily liquid was deposited at the bottom of the vessel.
Gradually the absorption of chlorine diminished, but did not cease
until several days had passed, after which the bubbles were increased
in bulk whilst traversing the liquid. There were then two liquids
in the vessel, the lower third was oily, whilst the upper part was
very acid and fuming. Either could be coloured green by a slight
excess of chlorine. The increase in weight indicated the chlorine
absorbed, and by saturating the acid liquor with bi-carbonate of
potassa, the quantity of muriatic acid produced was easily deter-
mined. Of the two liquids, the lightest was found to precipitate
by water, and to be a solution of the heavier in acid ; the quantity
thus dissolved was estimated by comparative experiments. The
quantity of carbonic acid produced was as nothing, the trace existing
probably came from the manganese. The experiment proved that
chlorine combined with alcohol in a volume equal to that of the
hydro-carbon present, estimated in the same state ; that half the
* We have ventured to alter the number of atoms, &c., referred to by M. Morin
in illustration, without, however, altering the sense of the statement. M. Morin
doubles the atom of carbon, and calls it vapour, &c. ; the consequence is, that in
the very passage altered, the theoretical impropriety occurs of saying, that fo'-car-
burettcd hydrogen is composed of two atoms of hydrogen and one of carbon. — Ed.
Chemical Science. 171
chlorine became muriatic acid, and that the other half formed a
substance of the same specific gravity as the hydro-chloride of
carbon. Hence, it may be concluded that chlorine acts on alcohol
as it does on olefiant gas ; that the composition of the substances
obtained in both cases is the same, and that the water of the
alcohol is not concerned in the action. A good result can only be
obtained in operating at temperatures close to 32°, in allowing only
a very slow current of chlorine, and in effecting complete saturation.
The operation will soon appear terminated, but in such cases a
very variable oily product will be obtained.
Action of Chlorine on Ether. — The same kind of experiment,
and with the same apparatus, was then made with ether, also
a hydrated hydro-carbon. By keeping the temperature at 32°, or
below; moderating the current of chlorine; and continuing the
operation until the saturation was perfect ; all the muriatic acid
produced passed into the third vessel, or that containing the
water. In place of the ether, nothing remained but a green
liquid impregnated with chlorine, and of the specific gravity of
chloric ether.
The muriatic acid produced represented half the chlorine : the oily
matter was equal to what the hydro-carbon in the ether could have
produced, as olefiant gas with chlorine. The quantity of carbonic
acid evolved was quite insignificant; the water of the ether was
inert during the action, and in fact, the action of chlorine is the
same whether olefiant gas, alcohol, or ether be used. Although all
proceeds successfully if every precaution be taken, yet inattention
easily gives erroneous results, If the saturation be incomplete, the
oily matter varies in density and quantity. If the current of
chlorine be rapid, ether is carried off into the water and escapes the
action. If the temperature rise, the muriatic acid and ether react
upon each other, and muriatic ether is produced.
The substances thus produced, though alike in composition, vary
in some properties, and principally in taste and odour; these differ-
ences, it is supposed, may be due to a little sweet oil of wine. That
made with the gases has a sweet penetrating taste and agreeable
odour ; those with alcohol and ether have an acrid taste, resembling
more that of peppermint ; in colour and some other qualities they
differ slightly. They agree, however, in specific gravity, which is
between 1.22, and 1.24 ; in extreme solubility in alcohol and ether;
in being almost insoluble directly in water, but soluble by means of
muriatic acid, and remaining in solution after the acid is neutralised.
All produce by combustion a green flame, and abundant vapours of
muriatic acid*.
6. BROMIDE OF CARBON.
The following account of this substance is extracted from a work
on bromine and its chemical combination, by C. Lcewig.
* Ann, do Chimie, xliii. 225.
172 Foreign and Miscellaneous Intelligence.
Bromide of carbon may be prepared in two ways ; according to
the first method, bromine is mixed with alcohol at 36° Baumti. The
mixture heats strongly, and if bromine is still added, a moment of
sudden effervescence supervenes, accompanied with disengagement
of vapours of hydro-bromic acid and free bromine. After the liquid
has cooled, there is added an alcoholic solution of caustic potash
until discolouration is produced ; water is then poured in, and the
alcohol is evaporated at a gentle heat. When the liquid begins to
cool, there separates a small quantity of a yellow oil, heavier than
water, and immediately after a concrete crystalline matter. The
alcoholic solution may also be diluted with a large quantity of water,
and in this manner the concrete substance equally separates with
the oil.
This combination, however, may be obtained in greater quantity
by the following process. Bromine is put along with ether for a
certain time, and the mixture is then distilled. At first there only
passes hydrobromic acid, and then comes a very clear oil, which falls
to the bottom of the liquid that has already passed. When the
distillation has been continued for some time it is interrupted, pure
potash is added to the residuum, and it is diluted with water. There
is then deposited a voluminous white mass which is washed with
water upon a filter. It is then melted at a very gentle heat, and
allowed to harden by cooling.
This bromide of carbon forms white opaque scales, greasy to the
touch, like camphor, and friable. Its smell is highly aromatic, re-
sembling that of nitric ether ; its taste is sharp, like that of pepper-
mint. In the fluid state it is transparent and colourless. It burns
as long as it is in contact with flame, and disengages vapours of
hydro-bromic acid. It is heavier than water, melts at a slight
degree of heat, evaporates at 212° F., and sublimes, forming aci-
cular crystals, having a pearly lustre. It is but feebly dissolved by
water, to which it communicates its smell and taste. When the
water is at 122° F., it is dissolved, and at a higher degree it is in part
evaporated with the vapour. Alcohol and ether easily dissolve it,
and the solutions are not rendered turbid by nitrate of silver.
Alkalies have no action upon it, even at the boiling temperature. Sul-
phuric, hydrochloric, and nitric acids have no. effect upon it. When
the melted bromide of carbon is submitted to a current of free gas,
chloride of brome is immediately formed. On heating it with the
oxides of iron, copper, zinc, &c., there are obtained metallic bro-
mides, and carbonic acid gas. By making it pass these metals in
the state of vapour, there are obtained metallic bromides and
charcoal. It is to this latter property that M. Lee wig has had
recourse for analysing the bromide of carbon, which is composed of
9.01 carbon, and 91.99 brome, the atomic weight of the latter being
F= 941.1*.
* Eclin. Nat. Journal, ii. 233.
Chemical Science. 173
7. PREPARATION OF PHOSPHURET OP LIME. — (Dr. Coxe.)
1 employ two Hessian crucibles, some of the inner members of
a nest. The larger of the two has a hole bored through its
bottom, and a test tube of a suitable size luted in with clay. The
phosphorus is put into the test tube, the top of which is loosely
covered with a piece of broken crucible to prevent the small pieces
of quicklime from running down into it. The lime is then put in
so as to fill this crucible and partly fill the upper smaller one,
which serves as a cover to it, and is luted on with some fine clay
a little moistened. The cover has also a small hole in its top to
afford an outlet for the air, or volatilised phosphorus, if there should
be any occasion for it. The whole is now placed upon the grate of
a furnace, with the test tube projecting through and appearing
below, and a charcoal fire kindled around it. The phosphorus may
be kept cool if it should be ' thought necessary, by making the tube
dip into the water, contained in a tin cup attached to the end of a
stick. When the crucibles and their contents are thoroughly red
hot, a chafing dish is substituted for the tin cup, and the phos-
phorus rising in vapour produces the desired change. The phos-
phuret should be preserved in a sealed vial. The same crucibles
may be used a number of times*.
8. IODIDE OF POTASSIUM A GOOD TEST FOR ARSENIC — CURIOUS
COMPOUND PRODUCED.
Professor Emmett of Virginia has recommended the iodide of potas-
sium, or iodine alone occasionally, as a useful test for white arsenic.
He found that when the iodide was added to a solution containing
only 2.8 per cent, of arsenious acid, or 1.8 per cent, of arsenite
of potassa, or when iodine alone was added to a solution containing
2.8 per cent, of arsenite of potassa, an immediate precipitation took
place. If the precipitation be performed with drops upon a glass
plate, then -jj^dth of a grain of arsenic is sufficient for the pur-
pose; the precipitate, when gradually formed, is white, adheres with
great tenacity to the glass plate, and then may be thoroughly washed,
and will present the following characters. Concentrated nitric acid
changes the white colour to a dark brown, purple, or even black,
from free iodine ; and starch added at the same time, becomes deep
blue. Strong hot sulphuric acid does the same ; when cold, it
merely produces a bright yellow, the latter effect is produced by
strong muriatic acid. Metallic salts are not likely to cause errors
in the use of this test, because, if originally present, they are sepa-
rated by the carbonated alkali used to dissolve the arsenious acid.
The presence of coffee, tea, milk, and other liquids, does not seem
materially to retard the precipitation.
The substance thus formed appears to be a curious compound.
It resembles arsenious acid in solubility and precipitation ; thus,
* Sillimaa's Journal; xvii. 349.
174 Foreign and Miscellaneous Intelligence.
hot water dissolves about 5.3 per cent and deposits nearly one half
on cooling-. It requires a much higher heat than white arsenic for
its volatilisation (550° Fahrenheit), and at 600° is decomposed,
giving off first arsenical fumes arid then evolving iodine. On ana-
lysing the substance it turned out to be a compound of
Arsenious acid . . 63 . 3
Iodide of potassium . 36.7
100.0
Notwithstanding the novelty of such a compound, in which it is
impossible to tell whether the white arsenic acts the part of acid or
base, although it is present nearly to the extent of five atoms, and
where no analogy to the composition of a double salt appears obvious ;
yet Professor Emmett observes there are facts from which its exist-
ence must be inferred. Thus iodide of potassium, even when added
in great excess, does not precipitate the whole of the arsenite of
potassa, nor is it capable of diminishing the alkaline reaction ; on
the contrary, when arsenite of potassa is so far neutralized by free
acetic or arsenious acid as not to affect turmeric paper, it acquires
this property by the addition of iodide of potassium, apparently in
consequence of a union between the latter substance and the excess
of arsenious acid, which while dissolved had the power of counteract-
ing the alkaline effect : other considerations lead to the same result.
If subsequent experiments should establish the existence of such
a compound, it will be a solitary but striking example of what may
be considered a chemical hybrid *.
9. AMMONIA IN NATIVE OXIDE OF IRON. — (Boussingault.)
Vauquelin shewed that rust of iron contained ammonia, and Che-
vallier shewed that the natural oxide of iron also contained the
same alkali. As the oxides the latter worked with came from a dis-
tance, it might be urged that they had acquired ammonia by the
way ; for if rust formed within houses absorbed ammonia, so also
might native oxides acquire that alkali in its transit from place to
place. M. Boussingault, therefore, sought to ascertain whether the
natural oxides of iron gave the substance immediately after their
extraction from the earth.
In the mine of Cumba near Marmato, a large vein of hydrated
oxide of iron in syenitic porphyry is worked as a gold ore. In a
part of this mine, called por a fuera, where the work proceeds with
activity, about a foot of mineral was broken down at the end of the
excavation so as to expose a fresh surface, and then a hole was
bored in the very middle of the vein ; after having been carried
eight inches deep, the powder of the ore was collected carefully in a
basin, placed under the hole, and touched by nothing but the tool.
Four ounces of this ore were then bruised and rubbed in distilled
* Sillimau's Journal, xviii., 58,
Chemical Science. 175
water, the filtered liquid was acidified by muriatic acid and evapo-
rated ; it left fifteen grains of residue, which being introduced into
a glass tube with a piece of quicklime slightly moistened and
heated, gave ammonia sensible not only to test papers, but also by
its strong odour. Hence it results, as M. Chevallier has stated, that
the natural oxides of iron contain ammonia, and this fact, conjoined
with that of Austin, that ammonia is formed by the oxidation of iron
in contact with air and water, acquires a certain degree of geolo-
gical importance*.
10. ATOMIC WEIGHT OF TITANIUM. — (Rose.)
M. Rose some time since endeavoured to ascertain the atomic
weight of titanium from the analysis of its sulphuret, but finds, as he
suspected, that the sulphuret often contains titanic acid, and there-
fore yields uncertain results. In fact, when chlorine was passed
over the heated sulphuret, besides the chlorides of titanium and
sulphur, titanic acid always appeared.
He has, therefore, resorted to the chloride of titanium as a more
definite compound ; a mixture of titanic acid and charcoal is heated
and chlorine passed over it ; the chloride of titanium formed is recti-
fied from off mercury or potassium t several times to remove the
excess of chlorine, and is then a clear limpid fluid like water,
leaving no trace of chlorine when decomposed by water. If this
chloride and water be brought together suddenly, heat is evolved,
and the solution is milky ; if the chloride is left in a moist atmos-
phere, the action takes place without the least formation of turbid-
ness. After some time the titanic acid is precipitated by ammonia,
carefully added so as not to be in great excess, exposed to a mode-
rate temperature to dissipate the excess, and filtered to separate the
titanic acid. The above liquor is then mixed with nitric acid, and
the chlorine precipitated from it by a solution of nitrate of silver.
The titanic acid and chloride of silver are then weighed and give data
to determine the quantity of titanium and chlorine in the original
compound. From the mean of many experiments thus made, it
would appear that one hundred parts of the compound contain
Chlorine . 74.46 . . 71.461
Titanium . 25.54 . . 23.539
and as 74.46 chlorine correspond to 16.82 oxygen, that the titanic
acid is composed per cent, of
Oxygen . 39.71 . I . 36.130
Titanium . 60.29 . | . 63.870
Dumas, some time since, endeavoured to ascertain the specific
gravity of the vapours of the chloride of titanium, and found it to be
6.836, that of air being 1. This would give the composition of the
above compounds as expressed in the second column of figures.
The cause of this difference between the results obtained is, at
* Ann. de Chimie, xliii., 334.
| Potassium does not act upon the compound at boiling temperatures.
176 Foreign and Miscellaneous Intelligence.
present, unknown, but unfortunately throws doubt upon both
processes*.
11. ON THE CRYSTALLIZATION OF GOLD. — (Professor Henslow, of
Cambridge.)
A small glass-stoppered phial, containing a solution of gold in a mix-
ture of nitric and muriatic acids, had stood long neglected for a
considerable time (perhaps four or five years) in a cupboard. Upon
accidentally discovering it, I found a portion of the acid had escaped
and the gold crystallized. This effect had probably been promoted
by a flaw in the phial, which extended through the neck, and a little
way down its length. The stopper, in consequence, must have been
slightly loosened, and thus allowed more space for the formation of
a thin dendritic crystallization of the gold. This was further con-
tinued down the inner surface of the phial, and was there sufficiently
thick to admit the impression of minute but distinct crystalline
facets. A small crystallized lump of gold lay at the bottom of the
phial, but I believe this had been originally attached to the rest, and
merely fallen by its weight, as I have since observed to be the case
in another portion. Around the stopper, and along the flaw, there
was a saline concretion, which tasted like sal ammoniac, and as
ammonia was kept in the same cupboard, it had probably united
with the muriatic acid as it exuded. Upon finding this specimen, I
examined some other metallic solutions, and found a similar separa-
tion of the metal had taken place, in a phial containing a solution
of platina, and in another containing a solution of palladium. In
both these cases a thin, interrupted, and dendritic lamina of metal
might be seen between the stopper and the neck, but the crystalliza-
tion had proceeded no further. I unstoppered the phial containing
the platina, and the lamina (as might have been expected) imme-
diately disappeared in the form of a slight muddy film. The palla-
dium I still possess. Probably this phenomenon maybe of frequent
occurrence ; but as the separation of the metal does not often extend
below the neck of the phial, it may have passed unnoticed. These
facts, if multiplied, may perhaps serve to throw some light upon the
mode in which the dendritic laminae of native gold, silver, &c., are
formed in rocks f.
It would have been satisfactory to know whether, in the case de-
scribed by Professor Henslow, any lard, wax, or lubricating matter
had been originally applied to the stopper of the phials, which could
have caused or promoted the effect of reduction. The Professor
has not before met with any cases of reduction in the crystalline
form of gold from solution in acid. These, however, are not uncom-
mon. We have specimens of gold finely crystallized, by gradual
reduction and deposition, from an ethereal solution of its chloride ;
and both gold and silver, and also other metals, may be reduced
» Aunalen der Physik, xv.; 145. f Mag. Nat. Hist. i.; 146.
Chemical Science. 177
from these solutions in acid, and crystallized, by leaving pieces of
charcoal, phosphorus, &c., in them. — Ed.
12. SALICINE — ITS POWER AS A FEBRIFUGE. — (Leroux.)
A very important Memoir by M. Leroux, which was presented to
the Academy of Sciences, has been most favourably reported upon
by MM. Gay Lussac and Majendie. It relates to nothing less than
the discovery of a principle in indigenous plants which may replace
quinia and cinchonia as medical remedies. Being aware that the
willow had been employed advantageously as a bitter and febrifuge,
M. Leroux sought in it for some active principle, and ultimately
sent two preparations to the Academy, one called salicine, the other
sulphate of salicine. He at first thought the new principle was a
vegeto-alkali, but when afterwards in Paris, he convinced himself
that it had no power of neutralizing acids, did not combine with
them, was rendered uncrystallizable by them, contained no nitrogen,
and was not a vegeto-alkali. The sulphate was a mistake.
Salicine is in the form of very fine nacreous white crystals, very
soluble in water and alcohol, but not in ether; it is very bitter, and
partakes of the odour of willow bark. In order to obtain it, three
pounds of the bark of the willow (salix helix), dried and pulverized, is
to be boiled in fifteen pounds of water, with four ounces of carbonate
of potash, for an hour ; it is to be filtered, and, when cold, two
pounds of solution of sub-acetate of lead added: when settled, it is
to be filtered, treated with sulphuric acid, the rest of the lead pre-
cipitated by sulphuretted hydrogen, the excess of acid neutralized by
carbonate of lime, again filtered, the liquid concentrated and satu-
rated by dilute sulphuric acid, then boiled with animal charcoal to
remove colour, filtered hot, crystallized repeatedly, and dried with-
out access of light. About one ounce of salicine will be obtained
in the large way; probably twice the quantity would result, for great
loss is occasioned by the above numerous operations. It may be pre-
served in well-closed bottles, and does riot attract moisture.
As to the medicinal powers of this substance, M. Majendie states,
that his own experience of its effects in intermitting fevers is
favourable, and that he has seen three doses, of six grains each, stop
a fever. He quotes the experiments of MM. Miquel, Husson,
Bally, Girardin, Cognon, &c,, at the hospitals and elsewhere, in its
favour : they all agree in its anti-febrile power, and in stating that
from twenty-four to thirty grains of salicine will arrest the return of
the fever, whatever may be its kind. This is nearly the same as the
dose of the sulphate of quinia.
In concluding, the commissioners state, that M. Leroux has
discovered in the willow (salix helix), a crystal I izable principle
which approaches sulphate of quinia in its anti-febrile power,
and that this discovery is, without contradiction, one of the most
VOL, I. OCT. 1830. N
178 Foreign and Miscellaneous Intelligence.
important that has fyeen made for many years in pharmaceutical
chemistry*.
13. PREPARATION AND COMPOSITION OF MALIC ACID.
This curious vegetable acid has been obtained pure and crystallized
by M. Liebeg, and carefully analysed, for the purpose of setting the
discordant results of different chemists at rest. The expressed juice
of the ripe fruit of the mountain ash was boiled with animal char-
coal, which had previously been purified by muriatic acid ; and a
certain quantity of potash added, but so as to leave a great excess
of acid ; the whole evaporated till thick as syrup, then mixed with
five or six times its volume of spirit of wine, and the clear, vinous
liquor, after separation from the mucilaginous matter, distilled. The
thick viscid residue of the distillation was again acted upon by
alcohol, which entirely did away with the mucous state. Being
again distilled, the residue was diluted with much water, precipi-
tated by acetate of lead, and the malate of lead obtained, decom-
posed in water by sulphuretted hydrogen. The addition of potash
and treatment by alcohol has for its object the separation of tar-
taric acid and tartrate of potash, which occurs in the original juice,
and which otherwise would have given a mixture of tartaric acid
with the malic. As directed, the malic acid can contain only citric
acid, or traces of tartaric acid ; when concentrated, therefore, am-
monia is to be added in quantity insufficient to neutralize the liquor ;
alcohol, equal in volume to the liquid, is to be added also, and the
whole allowed to cool, when quadrangular crystals of the acid
malate of ammonia will be obtained, the salt being very little
soluble in alcohol, even though diluted. These dissolved in water,
precipitated by acetate of lead, and the precipitate decomposed by
sulphuretted hydrogen, yield pure malic acid ; which will be found
to crystallize by evaporation in the air, forming, first, acicular cry-
stals, and ultimately a solid crystalline mass.
A crystallized malate of zinc was then formed, resembling in
properties that described by M. Braconnet. By a heat of 212° it
loses ten per cent, of water, without change of form ; at 248° it lost
other ten per cent., then becoming a white coherent powder. By
analysis, the salt gave 46.734 malic acid, 32.711 oxide of zinc,
20 . 555 water, the oxygen of the oxide, water and acid being as
1:3:4. Hence the equivalent of malic acid is 57 . 3, hydrogen
being unity.
The malate of silver is anhydrous at 212°, and composed of
66.975 malic acid, 33.026 oxide of silver per cent., which gives the
equivalent number of malic acid as 57.2. When the dry salt is
decomposed by heat, it blackens only for an instant, and yields
carbonic oxide gas, which burns like alcohol, and contains no
empyreumatic matter.
* Ann. de Chiraie, xliii.,440.
Chemical Science. 179
The acid malate of ammonia was then decomposed in the manner
adopted by MM. Liebeg and Woehler, with the hippuric acid*. It
gave azote and carbonic acid in the proportion of 1 : 8, indicating
four atoms of carbon in the acid. The hydrogen was determined
by burning the dry malate of zinc with oxide of copper, and collect-
ing the water by chloride of calcium. The results came out as
4 atoms carbon, 24 ; 2 hydrogen, 2; 4 oxygen, 82; =58: but as
this was too high, as compared to the conclusions respecting the
equivalent number, and as it was the same with the composition of
dry citric acid, excess of hydrogen was suspected ; and as a trace of
water in the salt used would account for this excess, other experi-
ments were made with the anhydrous malate of silver. This salt
gave little more than one atom of oxygen, and the composition of
malic acid may therefore be considered as follows : —
4 atoms carbon . . 24
1 „ hydrogen . . 1
4 „ oxygen . . 32
Equivalent number . 57f
14. ULMIN, OR ULMIC ACID, AND AZULMIC ACID.
The following points relative to the history of ulmin are abstracted
from a thesis by M. P. Boullay on this subject. This substance
derives its importance from the numerous circumstances which give
rise to it, and the daily conversion of numerous vegetable matters,
especially those in wood, into it. Its existence in vegetable earth, in
manure, and in the sap of plants, shews the important part which it
performs, and it is probably the most valuable compost known. It
occurs in enormous quantities in brown earth, turf, &c., and Hol-
land probably owes the superiority of its agricultural productions
to the quantity which it naturally possesses.
M. Boullay has considered it as an acid, and gave it a corre-
sponding name, because of its power of combining with bases. It
was first found by Vauquelin in an exudation from the elm tree ; M.
Braconnot formed it artificially. It is produced in the distillation of
wood in soot, and may be formed by the action of sulphuric and
muriatic acids upon many vegetable substances.
Ulmic acid differs from the substances produced by the action
of air or oxygenizing bodies, on extracts, tannin, gallic acid, or
gallates, both by its colour and solubility in alcohol. It is more
probable, from the properties of the resulting substance, that when
gallic acid or the gallate of ammonia is exposed to air, a new sub-
stance, not sufficiently examined, is produced.
The composition of ulmic acid is the same as that of dry gallic
acid, but it has a much feebler saturating power ; its equivalent
number is to that of gallic acid as 5 : 1. It has been analysed by
* Quart. Jour, of Science, vol. vii. p. 424. f Ann. de Chim. xliii. 259.
N 2
180 Foreign and Miscellaneous Intelligence.
Boullay, and gallic acid by Berzelius ; the proportions they obtain
are as follow : —
Ulmic Acid. Gallic Acid.
Carbon . . 56.7 57.08
Water . . 43.3 42.92
equal to three proportions oxygen, three hydrogen, and six of carbon.
Hence it was supposed, that gallic acid differed only in water of
crystallization, but all attempts to deprive it of water, and convert
it into ulmic acid, failed.
The ulmates of the metals, although insoluble in saline so-
lutions and in excess of ammonia, are, when well washed, soluble
in water, like the ferro-prussiate of iron. They take fire at a tem-
perature much below a red heat, and burn. Three of them were
found by experiment to be composed, per cent,, as follows : —
Oxide of Silver. Of Lead. Of Copper.
28.57 . 26.86 . 10.5
Ulmic acid 71.43 . 73.14 . 89.5
Hence the equivalent of the acid consists of fifteen proportions of
oxygen, fifteen of hydrogen, and thirty of carbon, which, taking
hydrogen as unity, is 315. This is precisely five times the number
of gallic acid.
The feeble capacity of saturation possessed by ulmin may, per-
haps, be important in nature, for a large quantity of this food of
plants may in consequence be transmitted to them from decomposing
substances, by small quantities of alkali or ammonia. The earthy
ulmates, and especially that of lime, are not quite insoluble, and
withal are capable of being suspended so perfectly in fluids as to
be useful in the nutrition of plants, whilst still they are not so likely
to be washed away as the soluble ulmates.
Azulmic Acid. — By this name M. Boullay designates a substance
which has the same kind of relation to ulmic acid that azoted organic
matter has to such as is of vegetable origin. The carbonaceous
product left by the spontaneous decomposition of hydrocyanic acid
is azulmic acid, and not a carburet of azote. It contains hydrogen,
and can combine with salifiable bases in the same manner as hydro-
cyanic acid itself. Azulmic acid is not soluble either in hot or cold
water or alcohol : strong cold nitric acid dissolves it, forming a
reddish solution, precipitable by water. The alkalies dissolve it
very freely, producing deep-coloured solutions : the acids precipitate
these solutions, as do also the metallic salts. By heat azulmic acid
gives first hydrocyanate of ammonia, then cyanogen, and leaves
carbon. When analysed, the proportion of azote to carbon was in
volumes as 2 to 5. Hence, upon theory, it will consist by weight
per cent, of 47.64 azote, 50.67 carbon, and 1.69 hydrogen.
Pursuing the analogy between ulmic and azulmic acid, M. Boullay
endeavoured to form the latter by heating gelatine with potassa, in
imitation of M. Braconnot's process for forming ulmin ; and, in
fact, azulmic acid appeared to be produced. Azulmic acid is pro-
Chemical Science, 181
duced also not only by the spontaneous decomposition of hydrocyanic
acid, but by those of hydrocyanate of ammonia, of cyanogen dissolved
in water, by the action of cyanogen upon bases, and indeed whenever
compounds of this substance are experimented with. The action of
weak nitric acid on cast iron, or the carbon it contains, produces a
similar substance ; and as azulmic acid appears to combine with
concentrated nitric acid, there is reason to believe that artificial
tannins are only combinations of this body with nitric acid, or at
least that they contain an analogous substance*.
15. ON GASEUM AND MILK. — (Braconnot.)
An excellent, because practical memoir on milk has been published
by M. Braconnot, in the Annales de Chimie, xliii. 337, which offers
many applications of a substance long but not thoroughly known,
not a few of which we anticipate will hereafter come into use.
This substance is caseous matter, or, as he has called it, caseum.
Soluble Caseum, and its Applications. — 2500 parts (grammes) of
the curd of new cheese, as sold in the market, were heated to 2 12°
for some time : it contracted, and became a glutinous elastic mass,
swimming in much serum. Being washed in boiling water, to re-
move the acid serum, and dried, it weighed 469 parts. It was a
compound of caseum with acetic and lactic acids : being divided, put
into sufficient water with 12.5 parts of crystallized bicarbonate of
potassa, and heated, it dissolved with effervescence, producing a
mucilaginous liquor, distinctly reddening litmus paper. Being
evaporated carefully, with continual agitation, it left a soft portion,
which, as it cooled, acquired consistency, was drawn out between
the fingers into thin portions, and then dried in the air upon a sieve :
it weighed 300 parts. This soluble caseum is a surcaseate of po-
tassa, containing still butter and salts. It resembles isinglass, is of
a yellow-white colour, translucent, and of a stale taste : it is per-
fectly soluble in hot or cold water, producing a fluid rendered milky
by the presence of butter.
In this impure state the substance is easily prepared : instead of
the bicarbonate, the potash or soda of commerce may be used. The
following are hints for its application. Like gelatine, it may be
preserved without alteration for any length of time, and may be
obtained in enormous quantities, if required. Associated in various
ways with food, it must prove of the greatest importance on board
vessels for long voyages. Its aqueous solution, sugared and fla-
voured with a little lemon-peel, makes an agreeable and nourishing
drink for invalids. It is a powerful cement : its solution, evapo-
rated on glass or porcelain to dryness, cannot be removed without
injury to the vessels ; its hot concentrated solution has been applied
with great success to join glass, porcelain, wood, and stone. The
same solution forms a brilliant varnish : being applied to paper, it
• Annales de Chimie, xliii. 273,
162 Foreign and Miscellaneous Intelligence.
makes labels, which, when moistened and attached, adhere with
great force. It may be used instead of isinglass in dressing silks,
ribands, gauze, preparing artificial flowers, &c. It has not answered
in endeavours to clarify beer, but is equal to milk or cream in the
clarification of table liqueurs, giving them the softness and qualities
of age. It may be used in place of creamed milk in the clarification
of beet-root, sugar, syrups, &c., in conjunction with animal char-
coal, without exciting any fear regarding the presence of serum.
M. Braconnot thinks also, that by the help of a little ammonia the
greater part of the curd previously separated as above from its serum
may be taken up and converted into a dry substance, which, with
the help of earthy salts, will be of great service in clarification : for,
having dissolved some of this preparation in water, a small quantity
of muriate of lime, sulphate of magnesia, or even sulphate of lime
in powder was added : the liquid remained clear whilst cold, but the
slightest effect of heat made it coagulate uniformly throughout ; the
coagulum gradually contracted, and a perfectly clear liquid issued
from it.
Milk has always been considered as a certain antidote in some
cases of poisoning. The soluble caseum will perform the same
office against most of the metallic salts, but there is reason to
believe that white of egg is better than either against corrosive
sublimate.
Chemical Properties of Caseum. — Caseum is an acid which,
because of its tendency to combine with almost every substance, it
is very difficult to obtain pure. The soluble caseum already de-
scribed is to be dissolved in boiling water, put into a funnel, the
aperture of which is stopped, and left until a layer of cream has
collected on the surface. After removing this, a little sulphuric
acid is to be added, which will form a clot of sulphate of caseum :
this is to be well washed and then heated in water, with just enough
carbonate of potash to dissolve it. The mucilaginous liquor formed
is, whilst hot, to be mixed with its volume of alcohol. It is neces-
sary that no deposit form at the moment ; it should occur only in
the course of twenty-four hours, and will include the butter, the
sulphate of potash, and part of the caseum. All is to be placed on
a cloth, and a clear transparent liquid will pass, which, evaporated
to dryness, leaves caseum pure, except in retaining a minute portion
of potash.
Caseum, or caseic add, thus obtained, is a dry diaphanous sub-
stance, resembling gum arabic in appearance, and unalterable in
the air. It reddens litmus paper, is soluble in hot or cold water,
forming transparent viscid adhesive solutions, yielding by evapora-
tion transparent pellicles, which again dissolve in water. The mi-
neral acids, except the phosphoric, when added to the liquor, unite
to the caseum, and produce white, opaque, coagulated, insoluble
masses. Very weak solutions are not thus coagulated, as may be
seen by adding a little diluted sulphuric acid to such ; heat does not
Chemical Science. 183
cause the effect, but the moment a little lime is added it happens at
once. Milk with twice its bulk of water is not coagulated by sul-
phuric acid cold, but apply heat and the effect is produced, because
a little phosphate of lime in the milk then becomes sulphate, and
acts as above. Generally, the combinations of cheesy matter with
acids are irnputrescent. Well washed sulphate of caseum was left
with water for a long time : it gradually disappeared, but produced
no putrid odour.
Vegetable acids precipitate caseum, unless in excess. Potash,
soda, and ammonia produce very soluble compounds with it, which
are perfectly transparent, unalterable by air, and resemble gum.
All earthy bases and metallic oxides form insoluble compounds. All
salts, except those with base of potash, soda, or ammonia, combine
with caseum to form insoluble compounds. Even a little selenitic
water put into a solution of caseum, though it causes no change at
first, yet, when heat is applied, produces insoluble pellicles, which
are a compound of the caseum and earthy salt. The same or still
more striking coagulation happens with sulphate of magnesia and
acetate of lime.
Strong alcohol does not affect caseum ; weak alcohol dissolves it.
Sugar renders a solution of caseum more liquid : gum arabic renders
it quite insoluble, probably from the presence of earthy salts in it.
Infusion of galls acts with it as with gelatine. M. Braconnot sus-
pects that vegetable albumen is nothing more than caseum with
some earthy salts present.
Improved Milk. — Besides caseum and butter, milk contains salts,
&c. which are not particularly desirable. M. Braconnot took 2J litres
(4.4 pints) of milk, heated it to 113° F., gradually added dilute muri-
atic acid, and agitated the whole. The curd formed contained the
caseum and butter, and, being separated from the whey, was gradu-
ally mixed with 5 grammes (77 grains) of crystallized sub-carbonate
of soda, reduced to powder and warmed. No water was added,
but the whole gradually dissolved. It had the weak acidity of recent
milk, and formed about a half-litre of cream (a fifth of the first bulk),
capable of numerous applications in domestic economy. If made
up to its first bulk with water and a little sugar, it forms a milk
more agreeable than the original; or it may be flavoured, &c., and
used as cream. If it be heated with about its weight of sugar, it
becomes remarkably fluid, and forms a perfectly homogeneous syrup
of milk, which will keep for any length of time, and which, by the
mere addition of a sufficient quantity of water, forms a perfectly
homogeneous white opaque liquid, which is in every respect like
sugared milk of improved flavour. The syrup diluted with water
forms a nourishing drink for invalids. Carefully evaporated, but not
beyond a certain limit, or the butter would separate, it gave, when
cold, a soft confection, which left for a twelvemonth in a loosely
stopped bottle, underwent no change. This, when exposed in thin
portions to the air, was rendered quite dry, and could then be crushed
184 Foreign and Miscellaneous Intelligence.
and kept for any length of time without change, being always recon*
vertible into useful states by the mere addition of water*.
16. MANUFACTURE OF CHARCOAL.
A new process, recommended in the Journal des Fore/5, for this
purpose, is to fill all the interstices in the heap of wood to be charred
with powdered charcoal. The product obtained is equal, in every
respect, to cylinder charcoal ; and, independent of its quality, the
quantity obtained is very much greater than that obtained by the
ordinary method. The charcoal used to fill the interstices is that
left on the earth after a previous burning. The effect is produced
by preventing much of the access of air which occurs in the ordinary
method. The volume of charcoal is increased a tenth, and its weight
a fifthf.
Mr. Doolittle, of Birmington, United States, has lately charred
wood in kilns constructed for the purpose. One was built of brick-
work, thirty feet diameter and nine feet high, to the opening of the
arch which inclosed the top. It had openings at the top and sides
for the purpose of admitting air, charging, extracting, &c., all which
openings were under regulation. The charcoal thus obtained was
exceedingly good in quality, free from stones, earth, &c., and very
abundant in quantity, the increase being, in the latter respect, some-
times half as much more as the old mode of burning would givej.
17. POTASH OBTAINED COMMERCIALLY FROM FELSPAR.
According to M. Fuchs, this important alkali may be extracted
from minerals containing it, by the following method : — They are to
be calcined with lime, then left for some time in contact with water,
and the liquor filtered and evaporated. M. Fuchs says he has thus
obtained from nineteen to twenty parts of potash from felspar, and
from fifteen to sixteen from mica, per cent§.
18. SALE OF SELENIUM.
Perfectly pure selenium (free from sulphur) is announced for sale,
at the price of four gold Frederics (ninety francs) per ounce of
Cologne (446 grains). Applications, post paid, with the money, is
to be made to the Ducal Office of the Mines of Harzgerode, in the
duchy of Anhalt.
* Ann. de Chim. xliii. 337. f Bull. Univ., D. xiv. 262.
J Silliman's Journal, xvii. 395. § Ann. de 1'Industrie, v. 278.
Natural History, #c. 185
§ III. NATURAL HISTORY, 8fc.
1. MECHANISM OF THE HUMAN VOICE IN SINGING.
A memoir on this curious subject has been read to the Academy of
Sciences by M. Bennati, and examined by MM. Cuvier, Prony, and
Savart. The former of these three philosophers has reported
thereon to the Academy. The principal object of the memoir is
to make known the powers of an organ in effecting the modulations
of the voice, which in this point of view has been little attended
to by physiologists. This is the soft palate, or the narrow part
of the gullet formed above by the uvula, at the sides by the
arches, and at the bottom by the root of the tongue. M. Bennati
has succeeded in constructing an instrument which can include
three octaves. He points out in his memoir the precautions
which should be taken in this respect for the instruction of young
persons destined to be vocalists; amongst one of the principles, is,
to interrupt the exercises at the period when the voice changes. M.
Bennati concludes his memoir by this proposition, that it is not only
the muscles of the larynx which serve to modulate the sounds, but
also those of the os hyoides, of the tongue, and of the veil of the
palate ; without which all the degrees of modulation necessary in
singing cannot be attained. From hence it results that the organ of
voice is an organ mi generis, an instrument inimitable by art, be-
cause the materials of its mechanism are not at our disposal, and
we cannot conceive how they are appropriated to the kind of so-
norousness which they produce. This result, although not entirely
new to science, appears to the reporters to be proved by M. Bennati
by new facts and observations, and to have acquired such develop-
ment as to fix the attention of physiologists*.
2. GLOBULES IN THE HUMOURS OF THE EYE.
MM. Ribes and Donne have lately discovered globules in the
humours of the eye, of a smaller size than those of the blood.
There are three orders of them : the first are in sinuous chaplets,
and very apparent ; the second are isolated, larger than the others,
aud surrounded by a black circle ; the third are least distinct, arid
resemble a kind of mist. The authors are disposed to question the
utility of so many parts of the visual organ in the production of
impressions on the retina. It is known that the removal of the
crystalline lens by extraction does not destroy vision. The rays
of light must be considerably modified by the globules of the
humours t.
* Revue Ency. xlvi. 502.
f Archiv. General. Medical Journal, v. 148.
186 Foreign and Miscellaneous Intelligence.
3. USE OP NITROGEN IN RESPIRATION — CYANOGEN IN THE BLOOD.
Dr. Rich, Professor of Chemistry in the Vermont Academy of .
Medicine, has put forth a view of the part which nitrogen performs
in respiration, to produce cyanogen, which then exists in the blood
as cyanide of iron. He quotes the observations of others, by which
the nitrogen of the atmosphere is shewn to be absorbed in respi-
ration, and also occasionally given out again in the lungs, and he
thinks there is no more difficulty in conceiving that it should enter
into the blood in the pulmonary vessels, and combine with the carbon
in the blood, just as oxygen does. Cyanogen would probably result;
and then, referring to the ordinary processes by which Prussian
blue is obtained from dried blood, Dr. Rich seems to consider it
just as likely that the process should merely transfer the cyanogen
already existing, as that they should cause its formation from the
carbon and nitrogen present. This view appears to him to explain
the difference which has existed amongst chemists relative to the
presence of iron in the blood. Englehart's process of detecting iron
in the fluid blood, or rather in the colouring matter of the blood,
namely, by passing chlorine through it for a time, and then testing
the clear solution, he conceives to depend upon the chlorine taking
away the cyanogen from the iron, and so bringing the latter into a
state indicative by the usual tests *.
Dr. Rich has not had the opportunity of supporting his views by
any experiment, although he suggests some. We cannot help ob-
serving that the idea of the cyanogen obtained by the Prussian blue
maker being merely that which pre-existed in the blood, appears to
be a very violent one. The quantity he can obtain from dry
blood is enormous, many times surpassing the weight of the co-
louring matter in it. Further, the colourless serum will yield plenty ;
and now, in fact, blood is but seldom resorted to for it, but hoofs,
horns, and other sources of animal matter, are used for the purpose.
4. ACTION OF THE PILE ON LIVING ANIMAL SUBSTANCES.
Being desirous of testing by experiment the opinion often enter-
tained and advanced, that secretions in the living body are the result
of electrical decomposition, M. C. Matteucci applied the poles of
a voltaic pile containing fifteen pairs of plates, to two wounds made
on the lateral parts of the abdomen of a rabbit, so as to leave the
peritoneum bare. The poles were of gold, and it was soon found
that a yellow alkaline liquor, containing many bubbles of air, col-
lected at the negative pole, whilst a yellow liquid with few bubbles
and slightly acid, collected at the positive pole. When the positive
pole was copper, it became covered with a green coat slightly acid ;
the same results were obtained by acting upon other parts of the
* Silliman's Journal, xviii. 52.
Natural History, 8fc. 187
body, as the liver, intestines, &c. The substance obtained at the
negative pole besides alkali, contained much albumen and coagu-
lated by heat ; the fluid at the positive pole also contained a highly
uzotated substance.
These experiments M. Matteucd considers as supporting the
opinion advanced above ; and considering the secreting viscera in
different feeble electric states, it is easy to conceive the production
of acid and alkaline substances characterizing the secretions, and
to understand the formation of new substances by the combination
of the nascent elements. The electric state of the organ secreting
particular fluids may also be deduced ; and still further it might
be expected, that alkaline secretions would contain substances
in which hydrogen and carbon formed the principal part ; whilst
acid secretions would contain bodies abounding more in oxygeu and
azote. A brief consideration of the analysis of those substances
which are found in the urine, milk, bile, saliva, &c., will shew
generally the truth of this deduction *.
5. ON THE DISORDERS ARISING FROM THE LONG-CONTINUED
USE OF IODINE. — (Dr. Jahn.)
The following is the account which Dr. Jahn gives of that diseased
state of the system, which results from along continued or excessive
use of iodine, and which it will be found differs much, as do also
the explanations of the effects, from the descriptions of MM.
Coindet, Gardiner, Sceter, &c.
When introduced into the organic fluids, iodine acts firstly and
principally upon the process of nutrition. The first evident effect
is an absorption of the fat, so that a gradual leanness is remarked.
At the same time, we may observe with a little attention, an aug-
mentation of all the excretions. The skin, in consequence of
an increased deposition of carbon upon it, appears dull and of
a livid hue ; there is great and clammy perspiration ; respira*
tion is obstructed, the urine is increased in quantity, and the
surface of it is often covered with an oily pellicle. The alvine
evacuations are increased, and the faeces are loaded with bili-
ous matter and contain but little mucus ; the seminal secretion
is increased, and also the menstrual discharge. * It is clear/ says
M. Jahn, ' that in this state the vitality of the veins and lymphatic
vessels is exalted, and the predominance of venous excitement is
shewn, by the swollen state of the superficial veins, and the blue
colour of the lips. The blood, it-may be inferred from the diminished
redness of the skin, and the feebleness of the arterial pulsations, has
acquired a more serous character, and is more liquefied, so that the
quantity of serum is greater in proportion to the cruor and fibrine.
The energy of the irritable tissues is comparatively diminished.
Hence the patient is more easily fatigued than before; digestion is
* Arm. de^Chimie, xliii. 259.
188 Foreign and Miscellaneous Intelligence.
irregular, the saliva and mucus are diminished, and complaint is
made of dryness of the mouth and throat. The nervous power is
also materially affected, and symptoms resembling hysteria and
hypochondriasis arise, morbid sensibility, lowness of spirits, timidity,
sensation of weakness, trembling of the limbs, similar to that pro-
duced by mercury, agitated sleep, with disagreeable dreams, &c.
At this period irregular and transient febrile attacks announce a
reaction of the constitution. If now the morbid condition be not
opposed, and if the iodine be continued, the above symptoms in-
crease in severity, and shortly the glandular tissues, the breasts,
testicles, and thyroid gland are diminished in substance. At length,
all those symptoms arise, which are said to constitute nervous con-
sumption.
M. Jahn has examined two bodies, which presented the traces of
the action of iodine. A woman, who having misused the remedy,
was attacked with enteritis, which proved fatal; and a man affected
with cancer of the stomach, who was treated by the internal and
external use of iodine, and who took very large doses of the tincture
secretly, in hopes of a more speedy cure.
In the bodies of these patients the fat had disappeared, the
various tissues had a withered and flabby appearance, the glands
were shrunk and soft, and also the mesenteric ganglia (which are
usually much developed in cancer of the stomach), the thyroid and
supra-renal glands, the liver, spleen and ovaries.
Notwithstanding the mischief sometimes inflicted by the use of
iodine, M. Jahn considers it one of the most valuable remedies
which has been recently discovered*.
6. CHLORINE AN ANTIDOTE TO HYDROCYANIC ACID.
MM. Persoz and Nonat have verified the favourable results which
M. Simeon had obtained relative to the remedy which chlorine
affords against prussic acid. They operated upon three dogs, upon
the eyes of which a drop of prussic acid had been placed. Dividing
the symptoms into three periods, namely ; i. uneasiness, ii. tetanus,
iii. interrupted respiration : they found that when chlorine was
applied in the first period, the relief was immediate, the respiration
became regular, vomitings and alvine discharges occurred, the
animal gradually regained its strength, rose unsteadily, and, in
about half an hour, was as lively as at first. Applied at the second
period, the symptoms were arrested, but the restlessness continued
awhile ; and though respiration was less painful, the convulsive
movements continued for ten minutes, then occurred vomitings,
&c., as before, and, at the end of an hour, the animal was perfectly
well. The two dogs thus treated being tried next day with the
same quantity of prussic acid, but without chlorine, died in a few
minutes.
* Med. Jour., xlix., p. 72.
Natural History, fyc. 189
In the third case, all the effects of the prussic acid were pro-
duced before the chlorine was applied ; the respiration had ceased
for twenty-five seconds, and the animal was rapidly perishing ; but
the chlorine not only recalled it to life, but ultimately restored it to
full vigour : the full effect only occurred, however, after some hours.
Ten days after it was quite well, and the paralysis of the abdominal
parts, which occurred in all, had, in this case, entirely disappeared.
After this, MM. Persoz and Nonat sought to ascertain whether
the prussic acid, being absorbed into the vessels and tissues, the
chlorine would follow and decompose it. Two dogs of equal
strength were taken, the crural veins laid bare, and separated from
the neighbouring parts, and especially the accompanying nervous
fibres; then a drop of prussic acid was put upon each vessel. The
effects were instantaneous ; a few drops of chlorine (solution) were
let fall on to one of the crural veins — the other animal was left alone.
The first was as immediately recovered as it was injured ; the second
died directly. The first felt no inconvenience after some hours,
except from the wound. Endeavours were then made to kill him,
by putting prussic acid upon the eye and upon the crural vein of
the opposite side ; but the animal only felt temporary inconvenience
and a few convulsive movements, and was very quickly at ease.
Hence it appears that the chlorine administered beforehand is taken
into the circulation, and is then an effectual remedy against prussic
acid.
Trials made with the chlorids of lime and soda, in place of chlo-
rine, shewed that they possessed no corresponding powers, being
quite inert as antagonists to the hydro-cyanic acid *.
7. ON THE CURE OP ANIMAL POISONS, AND PROBABLY HYDRO-
PHOBIA, BY THE LOCAL APPLICATION OF COMMON SALT.
(Rev. J. Fischer.)
The Rev. J. G. Fischer was formerly a missionary in South
America, and is anxious to call the attention of the public to the
probable utility of common salt, as a remedy in cases of hydropho-
bia, if at least the opinion be correct, that what will cure the bites
of venomous serpents will be efficacious in the former class of
cases. He says, * I actually and effectually cured all kinds of very
painful and dangerous serpents' bites, after they had been inflicted
for many hours; for immediately after I had applied my remedy the
pain subsided, and the patient calmed, which remedy was nothing else
than common table salt; and I kept it on the place or wound, moist-
ened with water, till all was healed, within several days, without ever
any bad effect occurring afterwards. I, for my part, never had an
opportunity to meet with a mad dog, or any person who was bitten
by a mad dog ; I cannot, therefore, speak from experience, as to
* Ann, do Ckimie., xlui., 324.
190 Foreign and Miscellaneous Intelligence.
hydrophobia, but that I have cured serpents' bites always, without
fail, I can declare in truth.'
Mr. Fischer then quotes Dr. Urban's practice from Hufeland's
German Medical Journal. He had six methods, but his most suc-
cessful was to apply a thick pledget, soaked in any saline solution, to
each wound, or to each place where the teeth had made a mark
without breaking the skin, and retain them there by bandages.
The best solution is of salt, one ounce, or one ounce and a half, to
a pound of plain water, and the wounds are to be kept constantly
moistened with it. The lint is to be renewed and soaked twice a
day ; the places wetted every two hours, and even washed by the
patient, especially if any indications of relapse, as itching or pain,
should manifest themselves.
A case is then quoted from the Kent Herald, and Morning
Herald of July 28, 1827, as follows : * A friend of ours was some
years since bitten by a dog, which a few hours afterwards died
raving mad. Immediately upon receiving the bite, he rubbed salt
for some time into the wound, and, in consequence, never experi-
enced the least inconvenience from the bite, the saline qualities of
the salt having evidently neutralized the venom, and prevented, in
all probability, a melancholy death by hydrophobia.'
That which induced Mr. Fischer to try the above remedy, in the
case of serpents, was ' a page of the late Bishop Loskiell's (with
whom I was personally acquainted), in his History of the Missions
of the Moravian Church in North America, which says, as far as I
recollect, that at least among some tribes, they were not at all
alarmed about the bites of serpents, having always in use such a
sure remedy as salt for the cure of them, so much so, that they
would suffer a bite for the sake of a glass of rum. It was this that
induced me to try the cure of venomous bites with salt, and the trial
has exceeded my expectations.' ' P. S. The advice of killing all
dogs is neither practicable nor necessary : apply salt to man and
dog, the bitten and the biter, all will be most probably well *.' &c.
8. ON RESTORATION FROM DROWNING BY INSUFFLATION OF THE
LUNGS.
At the sitting of the 22d May of the Royal Academy of Medicine,
M. Piorry reported the results of his experiments on the insufflation
of the lungs of living rabbits, of the lungs of sheep, and man, after
death. He concluded, first, that insufflation seldom causes rupture
of the lungs unless too long and too violently continued ; that death
is caused by a mixture of air and blood in the heart, or by a double
hydrothorax, or by the distension of the abdomen; that this insuffla-
tion may cause subpleural but not interlobular emphysema; and that
insufflation of the digestive tube is almost as promptly mortal as
that of the lungs by preventing the descent of the diaphragm and
impeding respiration. Secondly, that crepitation always indicates
* Me The lines which thus occur may any one of them be imitated
by the two cardboard bars held and moved in the hand ; the
whole system may then be obtained at once if one of the inde-
pendent wheels (Fig. 1.) be reyolved by the pin between the
fingers, and a single pasteboard bar (of equal width with the
radii) passed once, not too rapidly, before it ; by returning the
bar the lines are seen a second time. Should the eye not
readily catch the appearance, a black instead of a white single
bar may be used, or a shadow be thrown by an opaque bar
from a candle, or the sun, upon the revolving wheel ; and
then, to extend and follow out the forms, the bar should be
moved to and fro slowly before the revolving wheel, to the
extent of one half or the whole length of a radius, when it will
immediately be seen, that all the lines produced, even when a
grate is used, are merely the courses of so many points of in-
peculiar Class of Optical Deceptions^, 217
tersection between the radii of the wheel and the bars passing
before or behind it.
A variation in the mode of observing many of these curious
spectra, but which still further supports the explication given,
is to cast the shadows of the revolving wheels, either by sun
or candle-light, upon a screen, and observe their appearance.
The way in which the cogs or radii of the wheels shut out more
or less of a back-ground from the eye, as already described,
will enable them, to an equal degree, to intercept light, which
would otherwise fall upon a screen. When the two equal cog
wheels are revolved so as to have the shadows cast upon a
white screen, that shadow exhibits all the appearances and
variations observed when the eye is looking by the wheels in
shade at a white back-ground. The shadow is light where the
wheels appear dark, for there the light has passed by the cogs;
and dark where the wheels appear light, for there the cogs have
intercepted most of the rays. The screen should be near to
the wheels, that the shadow may be sharp ; and it is convenient
to have one wheel of rather smaller radius than the other, or
else to place them obliquely to the sun for the purpose of dis-
tinguishing the shadow of each wheel, and shewing how beau-
tifully the spectrum breaks out where they superpose. When
the spoke-wheels are revolved they also cast a shadow, pre-
senting either the appearance of fixed or moving radii according
to the circumstances already described. When the two small
spoke-wheels upon one pin are revolved in an oblique direc-
tion, their shadow exhibits very beautifully the lines often seen
in the wheels of carriages.
During these experiments the attention cannot but be drawn
to the observation of the figures produced by the shadow of
one wheel upon the face of the other. These are frequently
very beautiful, and combining as they often do with the designs
produced, as already described, are occasionally more striking
than any of the appearances yet spoken of. Mr. Wheatstone
is, however, engaged in an inquiry of a much more general
and important kind, which includes these effects, and which, I
trust, he will soon give to the public.
Several of the effects with wheels already described, and
218 Mr. Faraday on a
some new ones, may be obtained with great simplicity, by
means of reflection, in a very striking manner. If a white
cardboard wheel, with equal radii, he fixed upon a pin, and
rotated between the fingers before a glass, so that the wheel
and its reflected image may visually superpose in part, the
fixed lines will be seen, like those of Fig. 2, passing in curves
between the axis of the wheel and the reflected image. If the
person gradually recede from the glass, but still look through
the wheel in his hand at the reflected image, i. e., still retain
them superposed, which is best done by bringing the revolving
wheel close to the eye, he will see the lines or radii of the
reflected image gradually become straight, and when from
three feet to any greater distance from the glass, will see the
spectrum of the reflected image, having as many dark radii
upon it as there are radii in the wheel he is revolving. What-
ever the velocity, or however irregular the motion of the wheel,
these lines are perfectly stationary. The explanation of the
change of form and ultimate appearance of the whole, and of
the number and fixed position of the lines, will be so evident
when the experiment is made, in conjunction with what has
been said, as to require no further statement here.
A very striking deception may be obtained in this way, by
revolving a single cog wheel (Fig. 6.) between the fingers before
the glass, when from twelve to fifteen or eighteen feet from it.
It is easy to revolve the wheel before the face so that the eyes
may see the glass through or between the cogs, and then the
reflected image appears as if it were the image of a cog-wheel,
having the same number of cogs, but perfectly still and every cog
distinct ; instead of being the image of one in such rapid motion,
that by direct vision the cogs cannot be distinguished from
each other, or their existence ascertained. The effect is very
striking at night if a candle be placed just before the face, and
near to it, but shaded by the wheel ; in the reflection the wheel
is then well illuminated, and the reflected face or shadow
forms a good back-ground against which to observe the effect.
I have, perhaps, already rendered this paper longer than
necessary, but the singularity of the appearances and the
facility with which they may be observed, have induced me
peculiar Class of Optical Deceptions. 219
to suppose that many persons would like to repeat the expe-
riments, and must be my excuse for some further variations
in the mode of experimenting.
A disc of cardboard, about two inches and a half in diameter,
was cut into a wheel like Fig. 16. ; another disc, rather larger,
was cut into a similar wheel, and then the radii of one were
twisted obliquely like the wings of a ventilator, and the radii
of the other similarly set, but in the opposite direction : a small
hole being made in the centre of each, a large pin was passed
through tlfat of the smaller wheel, and then a small piece of
cork passed on to the pin to hold the wheel near the head, but
free to turn ; two or three beads were then added, the second
wheel put on, and then a second piece of cork ; the end of the
pin was then stuck into a quill or a pencil, and thus was formed
an apparatus very like a child's windmill, except that it had
two sets of vanes, each revolving in opposite directions. On
walking across a room towards a window, or a candle, with
this little toy in the hand, or blowing at it slightly from the
mouth, the lines were beautifully seen, being either stationary or
moving, according to the relative velocity of the two wheels. This
could be altered at pleasure by inclining the vanes more or less,
or by blowing towards the centre of the wheels, or towards the
edges when the larger hind wheel received more propulsive force.
Spinners or whirligigs formed of discs of cardboard stuck
upon pins, and upon which radii either straight or curved, or
other forms, had been drawn in bold lines with black ink, when
spun upon a sheet of paper, and then looked at through the
moving fingers or through equidistant bars of pasteboard
moved before them, shew a great many of the effects.
Finally^ a couple of open radial wheels (Fig. 1.) upon pins
or wires, if revolved between the fingers in different positions
and directions, shew a great many of these effects extremely
well. Their shadows may be thrown upon each other, or upon
the wall ; one may be held near the eye, when it acts like a
grate with parallel bars ; and if one side of each wheel is black
whilst the other is white, still greater variety may be obtained.
They will be quite sufficient, when employed in a few experi-
ments, to make, in this description, anything clear which I
may have left obscure.
220 Mr. Faraday on a
The curious appearance exhibited by the wheel animalcule
has such a resemblance to some of those described in this
paper, that they inevitably associate in the mind of a person
•who has witnessed both effects. This little insect has been well
described by Mr. Baker * and others, and can only be viewed
distinctly under a high magnifying power ; it then presents an
elongated sack-like form (Fig. 17.), either attached by the
posterior part to the side of the vessel containing the water in
which it exists, or else floating in the fluid. When the effect
in question is observable, there is seen the appearance of two
wheels, one on each side of the head ; they seem formed of
deep teeth or short radii, perhaps fourteen or fifteen in num-
ber ; the form of these teeth is not sharp or well defined, but
hazy at the edges ; the interval between them is perhaps rather
more than the width of the teeth ; the teeth are not distinctly
set on to a nave or axis, but appear sometimes even to melt
away or attenuate at the part toward the centre, and some-
times appear, as independent portions, i. e. as much separated
from the centre part or supposed place of attachment as from
the neighbouring teeth.
These parts are never seen as wheels, except in motion ; the
animal is sometimes seen without them ; the parts which pro-
duce the appearance being then either retracted and drawn
inwards, or disposed in other forms, for the animal is of a very
changeable nature. The motion of the wheels is conti-
nuous, as if they were spinning constantly in one direction
upon their axis ; the velocity is such as to carry the teeth
rapidly before the eye, but is not enough to confound the
impression of one tooth with that of its neighbours, and there-
fore they may be distinctly seen. Both wheels move usually
in the same direction ; and when the head of the animal is
towards the observer, the direction is generally the same as
that of the hands of a clock. Baker states, however, that he
has seen them move in opposite directions, and also has seen
the motion first discontinued, and then reversed, in the same
wheel. The velocity is not always the same, but varies with
the efforts of the animal to catch its food. Whatever the
* Baker on the Microscope, vol. ii. p. 266 ; see also Leemvenhoek, Phil. Trans.,
Nos. 283, 295, 337 ; and Adams on the Microscope, p. 548.
peculiar Class of Optical Deceptions. 221
mechanism of the parts, the result is, that currents are esta-
blished in the water towards the head of the animal, which
currents pass off outward from the edges of the apparent
wheels ; and little particles floating in the water may be seen
to pass towards the head, and be suddenly thrown off at the
edges of the wheels with considerable force.
So striking are the appearances of these animalcula, that
men of much practice in microscopical observation are at this
day convinced they do possess wheels, which actually revolve
continuously in one direction. The struggle in Mr. Baker's
mind between the evidence of his senses and his judgment,
illustrates this point in so lively a manner, that I may be
excused quoting his account of it : — ' As I call these parts
wheels, I also term the motion of them a rotation, because it
has exactly the appearance of being such. But some gentle-
men have imagined there may be a deception in the case, and
that they do not really turn round, though indeed they seem
to do so. The doubt of these gentlemen arises from the diffi-
culty they find in conceiving how or in what manner a wheel
or any other form, as part of a living animal, can possibly turn
upon an axis supposed to be another part of the same living
animal, since the wheel must be a part absolutely distinct and
separate from the axis whereon it turns ; and then say they,
how can this living wheel be nourished, as there cannot be any
vessels of communication between that and the part it goes
round upon, and which it must be separate and distinct from ?
To this I can only answer that, place the object in whatever
light or manner you please, when the wheels are fully pro-
truded they never fail to shew all the visible marks imaginable
of a regular turning round ; which 1 think no less difficult to
account for, if they do not really do so. Nay, in some posi-
tions you may, with your eye, follow the same cogs or
teeth whilst they seem to make a complete revolution ; for
the other parts of the insect being very transparent, they are
easily distinguished through it. As for the machinery, I shall
only say, that no true judgment can be formed of the structure
and parts of minute insects by imaginary comparisons between
them and larger animals, to which they bear not the least simi-
litude. However, as a man can move his arms or his legs
VOL. I. FEB. 1831. Q
222 Mr. Faraday on a
circularly as long and as often as he pleases by the articula-
tion of a ball and socket, may not there possibly be some sort
of articulation in this creature whereby its wheels or funnels
are enabled to turn themselves quite round ?
' It is certain all appearances are so much on this side the
question, that I never met with any who did not, on seeing it,
call it a rotation; though, from a difficulty concerning how it
can be effected, some have imagined they might be deceived.
M. Leeuwenhoek also declared them to be wheels that turn
round, vide Phil. Trans., No. 295. But I shall contend with
nobody about this matter : it is very easy for me, I know, to
be mistaken, and so far possible for others to be so too, that I
am persuaded some have mistaken the animal itself, which
perhaps they never saw ; whilst, instead thereof, they have
been examining one or other of the several water-animalcules
that are furnished with an apparatus commonly called wheels,
though they turn not round, but excite a current by the mere
vibration of fibrillce about their edges.'
Notwithstanding the evidence adduced by Mr. Baker, which,
as I have said, is admitted by some at the present day, it must
be evident, from a consideration of the nature of muscular
force, and the condition of continuity under which all animals
exist, that the rotation cannot really occur. The appearances
are altogether so like some of those exhibited in the experi-
ments already described, that I feel no doubt the wheels must
be considered not as having any real existence, but merely as
spectra, produced by parts too minute, or else having too great
a velocity when in use by the animal to be themselves recog-
nized. It is not meant that they are produced by toothed or
radiated wheels ; for that supposition would take for granted
what has already been considered as impossible — continual
revolution of one part of an animal whilst another part is fixed;
but arrangements may be conceived, which are perfectly
consistent with the usual animal organization, and yet com-
petent to produce all the effects and appearances observed.
Thus, if that part of the head of the animal were surrounded
by fibrillae, endowed each with muscular power, and project-
ing on all sides, so as to form a kind of wheel ; and if these
fibrils were successively moved in a tangental direction rapidly
peculiar Class of Optical Deceptions. 223
the one way, and more slowly back again, it is evident that
currents would be formed in the fluid, of the kind apparently
required to bring food to the mouth of the animal ; and it is
also evident, that if the fibrils, either alone or grouped many
together, had any power of affecting the sight, so as to be
visible, they would be less visible at the part through which
they were rapidly moving, than that through which they were
slowly returning; and at that place, therefore, an interval
would appear, which would seem to travel round the wheel, in
consequence of the successive action of the fibrils. But, if
instead of the whole group of fibrils acting in succession
as one series, they were to be divided by the will or powers
of the animal into fifteen or sixteen groups, the action being
in every other respect the same, then there would be the
appearance of fifteen or sixteen dark spaces, and as many
light ones disposed as a wheel ; and these would continue to
travel round in one direction, so long as the animal continued
the alternate action of the fibrils. This may be illustrated by
supposing Fig. 14 to represent a fixed circular brush, with long
hairs, and the little dots to be the sections of so many wires,
forming the arms of a frame which, when turned round, shall
carry the hairs of the brush forward a little, and then, letting
them go, allow them to return quickly to their first position.
If this frame be turned continually round, it would cause the
brush, when looked at from a distance, to appear as a revolving
toothed wheel, although in reality it had no circular motion.
Now, what is performed here by the wire-arms at the outer
extremity of the hairs, and the natural elasticity of the latter,
may, in the wheel animalcula, be effected at the roots of the
fibrillge by muscular power ; and in this or some similar way
the animal may have the power of urging the current necessary
to supply food, and, at the same time, producing the spectrum
of a continually revolving wheel, or even the more complicated
forms discovered by Leeuwenhoek (Fig. 15), without requiring
any powers beyond those which are within the understood laws
of Nature, and known to exist in the animal structure.
Royal Institution, Dec. 10, 1830.
Q2
224 On a Mode of erecting light Vaults
DESCRIPTION OF A MODE OF ERECTING LIGHT VAULTS
OVER CHURCHES AND SIMILAR SPACES.
BY M. DE LASSAUX.
(Communicated by Professor WHEWELI>, of Cambridge.)
"IY/T DE LASSAUX, of Coblentz, architect to the King of
Prussia, is the discoverer and restorer of this process,
and gives the following account of his investigations.
He had arrived in various ways at the conviction that what
are called the gothic and ante-gothic styles of architecture (the
pointed arch and round arch styles), are not only the most
appropriate for churches, but also the cheapest. He had
attempted to discover some easy means of erecting stone vaults
in such cases, thinking them highly desirable, whenever the
funds at the builder's disposal will permit them. Vaults which
are at the 'same time wide and light, belong incontestably to
the boldest and most ingenious of human inventions : they are
peculiarly suitable in religious edifices ; they are secure from
the devastations of fire; and, when introduced in public build-
ings, they correspond to the spirit of the celebrated decree of
the republic of Florence, enacted in the year 1294, that all
which is executed for the commonwealth should bear the lofty
impress of the common will.
M. de Lassaux was also aware, that at Vienna, at the pre-
sent time, very wide and flat domes are erected almost entirely
free-handed (i. e. without centering), and that in the neigh-
bourhood of that city, very flat ovens and wide mantlepieces *
are constructed almost in the same manner, and with the help
only of a few slight posts or poles. He endeavoured, there-
fore, to discover some mode of facilitating, by similar means,
the execution of wide vaults in churches.
His attempts for some time led him to nothing bearing on
* Brunelleschi constructed the cupola of the church of Santa Maria del Fiore
at Florence, without a centre. — J. S. ' At Bassora, where they have no timber
but wood of the date tree, which is like a cabbage-stalk, they make arches without
any frame. The mason, with a nail and a bit of string, describes a semicircle on
the ground, lays his bricks, fastened together with a gypsum cement, on the lines
thus traced, and having thus formed his arch, except the crown brick, it is care-
fully raised, and in two parts placed on the walls. They proceed thus till the
whole arch is finished ; this part is only half a brick thick, but it serves to turn a
stronger arch over it.' — Eton's Survey of (he Turkish Empire. — J. S.
over Churches and similar Spaces. 225
the point in question, except the usual methods of laying
down the vaulting lines, and some historical notices, which will
be mentioned subsequently. In the old church vaults which
are extant, there was little to be seen, as they are in almost all
cases covered with a coat of mortar or plaster.
About six years ago, however, happening to go into the space
above the vault of the line church at Ahrweiler, he observed
in the extrados of the vaults so remarkable a dissimilarity in
their height and curvature, that the thought in an instant
struck him, that it was impossible these could have been built
upon a regular centering. On a closer examination, it ap-
peared impossible to entertain any further doubt on this sub-
ject; and in various places, where the rubble work had been
laid bare, the whole mode and manner was exhibited of the
process which had been employed, and the opinion thus formed
was more and more confirmed by subsequent examination of a
number of other vaults.
The whole mystery resides in this, that these pointed-arch
cross-vaultings consist of separate, generally horizontal, courses ;
of which courses each has a small concavity, and consequently
forms a small vault by itself, as soon as its terminating points
have their due counterpoise. Now, as the bed-faces of the
individual courses of a regular pointed arch, that is, of one
which is described about an equilateral triangle, recede very
slowly from the horizontal line, and even at the summit make
with it an angle of only 60°, the adhesion of each individual
vaulting-stone of moderate dimensions, such as brick and
similar stones generally have, to the layer of mortar, is sufficient
to prevent the sliding of the stone before the termination of
the course ; and hence there is no difficulty in executing each
individual course free-handed and independently, and in lock-
ing it against its counterpoise. Against each course .already
locked, and consequently fixed and immoveable, we may begin
a new one, and so continue to the final termination of the
whole vault. All that is required, therefore, is a solid resist-
ance for the terminating points of each course. Now, such a
resistance may be supplied not only by solid obstacles, as the
external walls, but equally well by the reaction of a contiguous
course. Hence, if the groining-ribs or diagonal lines of the
226 On a Mode of erecting light Vaults
separate compartments are properly supported beneath, the
courses which rest on the same point perpetually keep each
other in equilibrium, and consequently no further contrivance
is needed than to execute the whole courses in the individual
horizontal planes at the same time, or nearly at the same time ;
that is, to carry the courses all the way round ; consequently
the process in such cross-vaulting is the same fundamentally
as in domes, when each course is locked by itself as a ring,
one ring is gradually laid upon another, and thus finally the
dome itself is locked, except that in these domes the upper
courses have steeper bed surfaces, and consequently the stones
will no longer remain in their places without the application of
other auxiliary means, but would slip down as soon as they
were laid, if not prevented in some other way. This is now
done in Vienna in a very simple manner, by means of some
strong ends of rope, which are fastened above, and somewhat
backwards, from the course to be vaulted, and hang down like
plummets, being loaded below by some stones tied to the rope.
As soon as a stone is laid, and by a moderate blow with the
hammer pressed against the preceding stone, one of these ropes
is brought over the stone, and the pressure produced by the
weight of the appended stone, combined with the adhesion of
the mortar, is sufficient to hold the stone till it is sufficiently
supported by the contact of the next stone ; and this in its turn
is prevented from slipping down by the pressure of the cord
upon it.
We very often find, however, over ancient churches, cross-
vaults, where the diagonal lines consist of semicircles, and con-
sequently the transverse and longitudinal lines, and also the
lines of subdivision in compound vaults, form somewhat de-
pressed pointed arches, of which the radii are usually three-
fourths, but sometimes only two-thirds of the diameter; — here
the same difficulty occurs in the upper courses, and probably
has been met by the same or similar methods. We sometimes
observe also a back-vaulting of those courses, of which we
shall have to speak again in describing the locking of the
vault.
The only difference between these old cross vaults and the
usual ones, consists in this ; that the latter are formed by the
over Churches and similar Spaces. 227
motion of two horizontal straight lines over four arches set
opposite two and two, and consequently all the horizontal lines
in the vault are straight lines ; and each course must be con-
structed as a vault in an upright position, so as to support
itself freely, which requires a very careful shaping of all the
individual stones, and a considerable thickness ; whereas in the
ancient vaults no horizontal line whatever occurs, and each
course is laid in a line somewhat curved outwards ; and con-
sequently incomparably less thickness and less labour is re-
quisite, and yet a far stronger arch is produced. A single
cross vault of the first kind, according to the profile Fig. 1, cut
Fig. 1,
horizontally, in the line a 6, forms a rectangular composition
of straight lines, as Fig. 2, while the other, according to Fig. 3,
consists of curves, which push with their extremities e e
against the outer walls ; and, resting with their other extremities
at d d in the diagonal lines upon two centerings which cross
each other, keep each other mutually in equilibrium, till by
closing up, or locking the vault, complete diagonal arches are
obtained, which now support themselves, and enable us to
remove both the centerings.
The way in which the separate divisions are closed up in the
old vaults is represented in Fig. 4, and the last courses are
generally back-vaulted; that is, the joints are flatter and not
so steep as those which the regular joint-section requires, and
as the above derivation of the forms of the stones would pro-
duce. At the same time, the two sides of the pointed arch
228
Fig. 3
On a Mode of erecting light Vaults
Fig. 5.
unite in a point, as in a simple-pointed arch, at the ribs or
groins only, and not in the intermediate spaces. In the latter
portions they form rather a very acute ellipse; and the wall-
scutcheon * also has this form not unfrequently, indeed almost
universally, where there is not introduced in this part some
ornamented band or moulding. Hence the vertex of these
intermediate compartments is higher than the vertex of the
diagonal ribs, and forms a flat arch from their point to the wall,
as is manifest from the section in Fig. 6.
* The portion of the wall, bounded by the arch, resembling an inverted escut-
cheon.
over Churches and similar Spaces.
229
But again, the separate courses are not always horizontal ;
they often ascend, according to Fig. 5, from the diagonal ribs
by a tolerably steep inclination towards the wall, sometimes
even at an angle of 45°. This, probably, was done for the
sake of concentrating more completely the push from the latter
upon the centerings of the former, and then changing it into a
nearly perpendicular pressure ; perhaps also for the sake of
giving a greater concavity, and, consequently, a greater strength
to the separate courses. Even rectilinear cross- vaulting, and, it
may be, even cylindrical-vaulting, may probably be executed
in this manner ; since, in this case, all the courses would form
oblique sections of a cylinder, and consequently would consist
of elliptical arcs.
We have hitherto, for the sake of making the subject more
easily intelligible, spoken only of simple vaults covering sepa-
rate square spaces, walled all round. But it is scarcely neces-
sary to observe, that exactly the same principle is the founda-
tion of all compound vaults, whether one row of separate
vaults is juxta-posited, in order to cover an oblong space ; or
several rows of vaulting compartments lie opposite to each
other, and are supported by pillars. The only difference which
then occurs is this : — that not only the diagonal lines of the
separate compartments, but also the transverse and longitudi-
nal arch lines, which determine the form of the vaults, are
supported by centering ; and also that the pillars, when their
230
On a Mode of erecting liyht Faults
distances from each other, or from the outer walls, are unequal,
as is the case in almost all churches, must have a certain
stability before they are vaulted over, since the push of the
surrounding vaults is unequal, and, consequently, they no
longer hold each other in equilibrium ; their push not being in
this case resolvable into a simple perpendicular pressure upon
the pillars. This, then, is the use of that massive wall which
is carried by the arches, and which binds the pillars together
in the direction of the length of the nave. This wall finds a
resistance to its ends 'in outer walls of suitable strength ; and
at its upper part sustains a great portion of the roof; and con-
Fig. 7.
over Churches and similar Spaces.
sequently, by means of its own weight, in combination with
that of the roof, exercises a powerful pressure upon the pillars,
which is more than sufficient to give them the stability requi-
site to enable them to counteract the unequal push of light
vaults. The profile, Fig. 7, of the Church of the Jesuits in this
place (built in 1615) will make this clear, since here we have
the still more unfavourable case, in which the vaults are not
only very unequal, but their points of incidence are not oppo-
site each other, being at different heights ; and consequently
the whole push of the vault (which is not pointed, but semi-
circular) operates upon the pillar, which has no support on
the other side ; nor are the outer walls, though only two feet
seven inches thick, strengthened by any buttresses ; while the
side windows have a width of only six feet for the interme-
diate piers: perhaps one of the boldest constructions of a
vault which is known. See the plan of the vaulting, Fig. 8.
Fig. 8.
In reality, indeed, the push of such thin vaults is not any-
thing which we need fear, since, according to the formulae of
Bondelet, or even those of Belidor, piers are sufficient for them
which have a smaller thickness than that which is usual in the
outer walls of high and wide buildings. Hence the ribs and
the filling in behind of the spring of the vault arches, supply
all the advantages which Bondelet, with truth, attributes to
vaults, of which the flanks are filled in behind, and which
232 On a Mode of erecting liyht Vaults
are thicker than those at the summit. e Voutes extradossees
moiti£ de niveau et moitie d'inegale epaisseur.' — Art. de Batir,
vol. iii., p. 328 to 332, and p. 380 to the end of the vol.
The author knows several old churches, with semicircular cross
or domical vaulting, where the side-walls have declined con-
siderably from the perpendicular ; and where the vaults, having
separated in the middle, the chinks have been at various
times again filled in ; and thus the semicircle has gradually
become a depressed arch. If it had, in these cases, been the
arch which pushed the walls asunder, it must necessarily have
fallen in as soon as the cracks began to gape ; that is, when
their edges no longer touched each other. That this did not
happen, gives the most convincing proof that no push at all
had taken place ; but that rather each half of the vault was
detached, and hung to the wall, and that its yielding was pro-
duced by other causes. These lie often in a deficient construc-
tion of the roof, but most commonly in the small care which
is generally taken in carrying off the water which falls on the
roof; in consequence of which, the rain-water for the most
part drips upon the outside of the foundation, and necessarily
causes in this, the most dangerous place, a continued settling,
and consequently a gradual outward yielding of the walls.
In order to make a small thickness of wall suffice, the skilful
ancients applied also another effective means — namely, to build
very slowly, and to put on the vault late, after the complete
drying and hardening of the mortar ; and till then, for the tem-
porary use of the church, to cover the roof simply with boards,
or perhaps, after the manner of so many basilicse, to leave it
quite open. This, however, cannot be done at present, when
a building must be completed inside and out by a fixed day.
The material of ancient church vaults is, on the Lower
Rhine, everywhere, the well-known tuf, which is manufactured
as Trass, modelled to the size of common tiles, and three or
four inches thick. On the Upper Rhine, beginning from
about Bingen, it is brick of small size : the thickness of the
vaults varies from four to eight inches : the execution is often
very slovenly, and different in almost every vault ; that is, the
concavity is sometimes very flat, sometimes very strong, some-
times again uncommonly neat and resembling an assemblage
over Churches and similar Spaces. 233
of eggshells. In the vaulting of the Minster at Ulm *, the tile
materials are known to have been mixed up with chopped
straw, which, in the burning, naturally was reduced to ashes,
and thus gave to the stone a degree of porosity, and conse-
quently of lightness.
The author found the same thing in the church at Kirch-
berg, near Zimmern ; but he observed that here, in an expe-
riment made with different mixtures, tiles of this kind lose very
much in strength, which, for such vaults, is far more injurious
than the small excess of weight of common solid stone would
be ; even the latter does not amount to half the weight of a
common grouting (filling-in of the inside of a wall) ; and, con-
sequently, operates rather advantageously, than prejudicially,
to the stability of a substantial building.
We find this kind of vaulting applied also in domes ; in
which case the circle is divided by ribs into compartments, and
compounded of several flat rounds. Among others, the
author found in an old tower at Andernach, a domed vault, of
which the horizontal section forms, not a circle, but four shell-
shaped pieces of circles, which rest upon two edges, cutting
each other at right angles. When, in later times, the ribs
were multipled, and a network of various forms was extended
over the vault, the intermediate spaces were smaller, and
could consequently, with still more facility, be vaulted with
free-handed vaulting.
The advantage of this kind of vaulting without centering
consists, not only in the very considerable saving of boarding,
and of the greatest part of the centering arches, but it gives
also a firmer vault ; since the settling takes place gradually
before the usual closing of the vault : indeed, the author
almost doubts, whether such thin vaults could be constructed
at all upon a boarded centering. Except this is supported by
scaffolding to an immoderate degree, the mere motion of the
labourers, in the course of the vaulting, must cause a perpetual
shaking, and, consequently, separations in the vault after it is
begun ; and even when the vault is brought to its closing,
and it is wished to loosen the centering, which is so extremely
* Ilaffner, Description of the Minster at Ulm, p. 11.
234 On a Mode of erecting light Faults
advantageous for the uniform closing of all vaults, the inevit-
able consequence is, bellying and cracking. If, on the other
hand, \ve wish to leave the centering standing till the complete
drying of the vault, the wasting of the mortar would cause all
the joints to open and crack. But the network formed b'y
the mortar in all the joints, gives to a thin vault of heavy stone
a peculiar strength ; as the author very clearly ascertained by
an experiment for the purpose. There is in this place a kind
of stone, which is used very advantageously for the lining of
walls, the pannels of ceilings, and the construction of chimneys.
It is a conglomerate of loose pumiceous sand, cemented into a
coherent mass by a loamy earth ; and is naturally so tender,
that it may be rubbed to pieces in the hand ; and, indeed, has
hardly more consistence than a swallow's nest. This mass lies
in layers some feet under the surface, in the country between
Engers and Bendorf : it is worked in stages, cut into loaves of
13 in. long, Gin. broad, and 4 or 5 in. thick, "and dried in the
air. With these stones set on the long narrow side, he ordered
a very flat vault (31 feet span, and 4J feet spring, and about
4 feet broad) to be thrown across between two old walls. Its
thickness was thus only 6 inches, or the 124th part of the
diameter of the semicircle, of which the arch was part ; con-
sequently, the stones suffered a pressure equal to that right
upon each stone of a semicircular vault of 62 feet diameter, and
therefore far greater than that which the stones could have
borne on the ground ; and yet this arch, although it could be
put in strong vibration with the hand, had so much strength
that a man could walk over it.
That the old vaults were built free-handed, and not upon a
boarded centering, no one can doubt. Who would have given
himself the trouble, so disproportionate to its object, of making
such a boarding vaulted according to each arch of the cen-
tering, when he might obtain the same end with one which was
quite common ? Besides, the unequal convexity in all such
old vaults shews that no gage or model was ever applied, but
the observation of the proper form was left to the choice and
practice of the mason. We often see, as has already been
said, a strong convexity pass into a flat one, or reversely;
when probably it had suddenly struck the mason, that he was
over Churches and similar Spaces. 235
vaulting too round or too flat, and when he set about correct-
ing his mistake too suddenly.
As to the epoch of the invention of this bold and uncommonly
ingenious mode of vaulting, the author has hitherto discovered
nothing exact or capable of being well substantiated.
In the cathedral at Cologne, the vaulting of the choir, so far
as can be discovered from below, appears to be still rectilinear,
and consequently vaulted on a boarded centering. In the
north aisle of the nave, on the contrary, the curvature of the
intermediate surfaces, as well as the horizontal position of the
courses, is very distinctly recognizable. Now, as we may
presume that the workmen in this cathedral were acquainted
with the practices in building which existed in their time, we
may place the invention of this kind of vaulting between the
completion of the choir and that of this side-aisle ; and, con-
sequently, according to Boisseree, between 1322 and the be-
ginning of the sixteenth century.
In books, the author, as has already been said, has been able
to discover nothing concerning the practical art of building.
There is, however, in De 1'Orme (CEuvres de Philibert de
VOrme, Rouen, 1648; the first edition appeared in 1568, during
his lifetime ; he died 1570, or, according to others, 1577), in
the 8lh chapter of the 4th book, a passage historically very
remarkable. These old church vaults are there called ' voutes
modernes et a la mode Fran9aise, que les maitres m^ons ont
accoustume de faire aux eglises et logis des grands seigneurs.'
He says further — * Ces fayons de voutes ont este trouvees fort
belles, et s'en void de bien executees et mises en oeuvre en
divers lieux de ce Royaume et signamment en ceste ville de
Paris, comme aussi en plusieurs autres. Aujourd'huy ceux
qui ont quelque cognoissance de lavraye architecture ne
suivent plus ceste fac,on de voute, appelee entre les ouvriers
la mode Franchise; laquelle veritablement je ne veux depriser,
ains plutost confesser que Ton y a faict et pratiquer de fort
bons traicts et difficiles.'
The separate ribs have here all particular names : thus in
Fig. 9, which occurs in De TOrme, the ribs A are called
Croissce d* ogives ; B, Liernes ; C, Tierccrons ou tiercerets ; D,
, when tlu-y lie against the wall and have only a half
236
On a Mode of erecting liyht Vaults
profile ; but arcs doubleaux when, as at E, they divide two
compartments r>£. vaulting from one another, and thus acquire
a stronger profile. He then gives a drawing, with an explana-
tion for laying down these different lines, and concludes very
naively —
1 Si quelques-uns desirent en scavoir davantage pour le pra-
tiquer, faut qu'ils s'addresserit aux architectes ou maistres
magons qui 1'entendent. Car il est mal-aise de le pouvoir
mieux expliquer, que par oeuvre et effect, c'est a dire en demon-
strant au doit et a 1'ceil, comme les pierres se doivent trasser
et assembler.' Subsequently, in the 9th chapter, De 1'Orme
gives a design for a simple vault over a church ; recommends
the laying the lines of the ribs exactly in the circle, that no
chink (aucun jouef) may occur; the not driving any large
wedge into the joints of the ribs ; the vaulting the pannels of
the vaulting (pendentifs) with brick or small stones ; the laying
the courses horizontally and according to the proper section of
the joints ; also the putting little thin mortar in the joints ; and
insures the durability of such vaults in the words — ' telles
voutes faictes ainsi dureront long temps.'
In the 10th chapter he adds a design out of his Nouvelles
Inventions de Charpenterie, published in 1561, in order to
shew that similar vaults may be constructed with wooden ribs
and hanging keystones ; but he himself is of opinion that it is
better to execute these in hewn stone. He then speaks of the
over Churches and similar Spaces. 237
various kind of ornaments, by means of hanging keystones,
which occur so commonly in similar vaults, and concludes
with the following remarkable words —
' Les ouvriers ne font pas seulement une clef suspend ue au
droict de le croissee d'ogives, mais aussi plusieurs, quand ils
veulent rendre plus riches leurs voutes, comme aux clefs on
s'assemblent les tiercerons et liernes, et lieux ou ils ont mis
quelque fois des rampants, qui vont d'une branche a une autre,
et tombent sur les clefs suspendues, les unes estant circulaires,
les autres en fa§on de soufflet, avec de guimberges, mouchettes,
daire-voyes, feuillages, crest es de choux, et plusieurs bestiaux et
animaux : qui estoient trouvea fort beaux du temps qu'on
faisoit telles sortes de voutes, pour lors appelle's des ouvriers
(ainsi que nous avons diet) voutes a la mode Franchise. Et
jacoit qu'aujourd'huy Ton ne s'en ayde gueres, et qu'elles soient
bien peu en usage si est-ce qu'elles sont tres difficiles, signam-
ment quand on les accompagne de pendentifs de pierre de taille.
Qui ne sont autre chose ainsi que nous disions cydevant que la
maconnerie qu'on met par dessus les branches. Comme vous
le pouvez cognoistre et remarquer en le figure ensuyvant, au
lieu de A B. Quand les diets pendentifs sont faicts de brique
ou petites pierres de maconnerie, ils ne sont tant difficiles : mais
les faisant de pierre de taille qui touche justement sur les
branches, les pieces s'y trouvent des gauchees, biaises, d'estrange
figure, selon Poeuvre qu'on faict, qui se monstre fort belle et
tres difficile a conduire *.'
* Similar wooden vaults, that is, vault-shaped coverings extended between
wooden ribs, or filled up with hurdle-work, and subsequently ornamented, are, in
the district of Coblentz, frequent iu small village churches, of which some are
very old ; on a larger scale, and decorated with a net work of ribs, they occur in
the Church of the Jesuits at Miinstereifel, built between 1612 and 1658. This
kind of make-believe architecture is therefore older than De 1'Orme thinks, but
m-u-rtheless has recently been produced as an ingenious and novel invention.
Similar apparent vaults, without visible and ornamented groin-edges, would
have at least the modern merit of cheapness. With moulded ribs, on the con-
trary, they become very dear, when they are executed in a good and durable
m;miier, and consequently with careful labour, and of good wood properly dry.
\N Ink- tin- author was unacquainted with the ancient mode of vaulting, and
thought, like so many other persons, that stone vaulting required immoderate
i'\l>r:i>e, he hail proposed a ceiling of this kind, that is without ribs, for a church,
which, fortunately, was not executed. In fact, the idea of a simplified construc-
tion h;id iiiUh-d him. As, however, such a process might in other places be
advantageous, a .-.hurl description may not be superfluous.
It is known that all horizontal lines in cylindrical and cross-vaulting are
VOL. I. FEB. 1831. R
238 On a Mode of erecting liyht Vaults
In the* llth chapter, De 1'Orme speaks at length of domes
over quadrangular spaces as a new invention (invention fort
ingenieuse pour couper un globe quarrement), and boasts,
with justice, that it is cheaper, because it requires no ribs, and
is easier to execute because the section of the joints is simpler ;
and, finally, he describes several kinds of this vaulting, accord-
ing to the quadrilateral circle, triangle, and oblique line.
Now, an invention which, in the time of Del'Orme, was still
called a la moderne, cannot easily be much older, and, com-
pared with the statement in BoissereVs great work on the
cathedral at Cologne, p. 16, according to which the north aisle
was vaulted after the year 1500, is, perhaps, to be placed only
in the beginning of the fourteenth century.
According to De 1'Orme, Mathurin Fousse, Derand, and
De la Rue also wrote on vaults: M. de Lassaux is not ac-
quainted with their works ; but it would appear that they limit
themselves to stone-cutting, to which the French, as we know,
began at that time to attribute perhaps too great a weight.
Roland de Valois also, who certainly was acquainted with the
above work and used it, repeats, in his * Dictionnaire d' Archi-
tecture,' only the names of the separate ribs, without adding
anything with respect to the practical execution of the vaults
themselves. Rondalet, in his excellent Art de batir, limits
himself in the same manner to the rules for the section of the
joints of the ribs.
The author has also endeavoured in vain to obtain oral infor-
mation. One mason, indeed, remembered to have heard from
his grandfather, that in keying these vaults it was very neces-
sary to avoid driving in the key-stone too hard, because if that
were done the sides would rise and belly. The last vault of
straight lines, and the vertical or oblique lines only are curved. Every light ceiling
is composed of boarding on a frame, on which the former is nailed in a perpendi-
cular direction. Now, as in general a surface of boarding is not capable of being
bent into a sharp curvature, the boards must be fastened in a horizontal position 011
a frame or skeleton formed of curves. If, on the other hand, we would have
another flexible material for the covering of the frame, for instance hoops, which
are in all respects preferable, the frame may be of straight wood, and consequently
may be prepared at a much smaller expense ; and the curved surfaces may be, by
means of hoops nailed on perpendic\ilarly or obliquely, of such a kind as may
best be laid on, and ornamented, without further preparation, with hair mortar
(which ought to be mixed with hog's bristles), and consequently prove a consider-
able saving in the boarding and reeding.
over Churches and similar Spaces. 239
this kind, so far as the author is aware, exists in the church of
Niederbriessig on the Rhine, a building of the year 1718.
Another opportunity must be taken of describing how the
author was so fortunate as to be able to vault two churches of
his own building with solid stone — how what has here been
said was applied in practice — and how so many other difficul-
ties of all kinds which occurred were happily obviated. In the
mean time a hasty statement of the dimensions may serve to
shew the applicability of this mode of vaulting in all cases.
The greater of these churches, which is entirely in the pointed-
arch style, js, in the clear, 57 feet wide and 48 feet high, is
divided by two rows of pillars, 17 feet from axis to axis, 3 feet
thick, and 25 feet high, into a middle-nave of 30 feet clear,
and two aisles ; and is vaulted over with pointed cross- vaulting
of the sandstone above described, and with intermediate ribs
of only 6 inches thick. All the centerings under this vault are
of wood from 4 inches to at most 5 inches scantling. The
greatest of these did not in any case consist of entire arches,
but only of segmental arches fastened together. The outer
walls, executed in irregular broken stones, are 3 feet thick, 50
feet high, and are strengthened by buttresses of the same thick-
ness, separate 17 feet from one another, projecting 4 feet, and
having a height of 30 feet. The tower, 21 \ feet square, and
in the wall-work 110 feet high, carries an octagonal spire 124
feet high, built of wood and covered with slates.
In the small church, in the round arch style, the buttresses are
in the interior, and are rounded into niches. The interval of these
is also 17 feet, and the breadth of the middle-nave, between the
pillars (which are 2£ feet thick and 22 feet high) is 22J feet ;
the whole clear breadth between the buttresses is 42 feet. The
pillars and walls are bound together both in a longitudinal and
transverse direction by semicircular ribs, and the compartments
thus formed are covered with cupola ceilings 6 feet thick, which
were vaulted freehanded, without any mechanical assistance.
At a later period, on the occasion of the vaulting of the
choir in another church, with a similar cupola of 24 feet square,
there occurred to the author a simple method of preserving the
complete accuracy of the form of the cupola. He caused a
very light pole, of the length of half the diagonal, and conse-
R 2
240 On a Mode of erecting light Vaults, 8fc.
quently of the radius of the sphere of the cupola, to be fastened
to its middle point by a double hinge, in such a manner that it
could be carried round in all directions, and consequently
could touch each point of the interior surface of the dome of
the assumed diameter*. The four gussets were then vaulted, one
after the other, in horizontal courses, and each stone pushed
forward so far that it could be touched with the end of the
moveable pole. In this way a circular ring was obtained of
the breadth of the square, on which were vaulted in a second,
third, and so forth, to the completion of the cupola. From
time to time, by the application of the pole, the complete regu-
larity of the spherical form was secured and properly preserved.
M. de Lassaux adds, that if he should hereafter have the
good fortune to erect other vaulted churches, he would limit
himself rigorously to the round-arch style. This style possesses
a superiority in the simplicity and completeness of its forms.
Moreover its spherical vaults, in consequence of the saving
of the ribs and their centerings, are considerably cheaper ; and
we can, therefore, with given funds, make our churches larger,
which, in consequence of the universally limited means, are
always built on too small a scale. This style is, moreover, the
more agreeable, because less that is fine in it has come down
to us ; while, on the contrary, our buildings in the pointed
style, compared with those of the ancients, always appear more
or less as a miserable subterfuge.
* Eton, in his ( Survey of the Turkish Empire,' says, ' I have seen cupolas of
a considerable size built, without any kind of timber support. They fix firmly in
the middle a post about the height of the perpendicular wall, more or less, as the
cupola is to be a larger or a smaller portion of a sphere ; to the top of this is
fastened a strong pole, so as to move in all directions, and the end of it describes
the inner parts of the cupola.'
( 241 )
ACCOUNT OF A NEW COMET OBSERVED BY M.DABADIE,
Professor of Mathematics at the College of Port Louis.
[Communicated by Sir ALEXANDER JOHNSTON from Sir CHARLES COI.VILLE,
Governor, &c. &c.]
Port Louis, 25th August, 1830.
[MEMORANDUM.]
TNCLOSED is a statement of the observations and calcu-
lations of our professor of mathematics at the Royal
College of Port Louis, showing the elements by which the
orbit of the comet of April, 1830, may be ascertained. It is
probable that his Excellency might be desirous of transmitting
this paper to Sir Alexander Johnston, as it will be valuable for
connecting the series of distances which may have been ob-
served in New South Wales and the Cape of Good Hope, on
the visit of this stranger ; for it does not appear that any notice
exists of this comet having before appeared, at least none of
the books we possess designate the same extent or inclination
of the orbit.
Ever yours, &c.
(Signed) C. TELFAIR.
Note. — The original observations are preserved in the
College.
Comet of the llth of April, 1830.
At seven o'clock, p. M. on the 16th of March, Mile.
asked me the name of a round nebulosity which she per-
ceived between the constellations of the Camelion and the
greater cloud. I was immediately convinced that it was a
comet. By the next day the nucleus had advanced nearly five
degrees towards the north, and it continued that direction with
242
Account of a new Comet.
a diminishing apparent velocity till it reached the eastern wing
of the Swan, where it disappeared toward the end of May.
The length of its tail never exceeded five degrees.
Not having an observatory in which to fix the instruments
that would have given at once the right ascension and declina-
tion, I made a great many observations of its distance from
different stars during its progress. The following are those
which I have used in the calculation of the six elements of
the comet.
March 19th, at 8 h. 45 m. 50 s. of true time, at Port Louis,
the distance of the comet from Canopus was 36° 11' ; at 9 h.
2 m. its distance from a Centauri was 34° 50'.
April 1st, at 16 h. 48m. its distance from y. Centauri was
69° 34'; at 17 h. 11 m. its distance from a Aquilse was
43° 50'.
April 15th, at 16 h. 25m. 5.0s. its distance from a Aquilae
was 21° 50' ; at 16 h. 40 m. 50 s. its distance from a Centauri
was 97° 39' 30".
Longitude of
the ascending
node.
Inclination
of the
orbit.
Place of the
perihelion.
Perihelion
distance, that
of the sun
being 1.
Passage of the
perihelion in
mean time of
Port Louis.
Motion.
S. 1>. M.
». M.
S. D. M.
7 18 31
49 46
7 28 13
0-897.
April 11.21h.
Direct.
ON THE PERMANENCE OF THE MAGNETISM IN STEEL
BARS.
BY S. H. CHRISTIE, ESQ., M.A., F.R.S., &c.
I
N the course of some magnetical experiments, made in
China, on the deviations of a magnetised needle due to
the action of an iron shell, Captain Wilson found, that when
the magnetism of the needle was disturbed, by applying the
pole of a magnet to the similar pole of the needle, considerable
changes were produced in its deviations; and, on Captain
Wilson's return to England, the experiments were repeated
and extended, and the results classed by Mr. Barlow. These*
were considered as quite decisive against a law which I had
several years before stated, that the deviations of a magnetised
needle, due to the action of iron, followedf. I was, therefore,
induced to repeat the experiments ; and having determined the
situations of the magnetic centres, the intensity of the mag-
netism in different points, and the points of greatest intensity,
in needles having their magnetism unequally distributed in
their two branches, that is, in which the symmetrical distri-
bution of magnetism had been disturbed, which had been
omitted to be done in the former experiments, I showed that
the results of those experiments were not only consistent with
the views which I had previously taken, but were such as I
had anticipated from the law referred to J.
While I was engaged in making these experiments, it became
a question with me, how far the deviations of a needle, having
its magnetism unequally distributed, observed at the beginning
of any set of observations, could be compared with those
observed towards the end of the same set, in consequence of
a tendency which might exist in the magnetism of the needle
to return to a state of symmetrical distribution. My first
object was, therefore, to determine whether any change that
could influence the results took place in the time occupied in
making a set of experiments, an interval of 3 or 4 hours.
* Plul. Trans. 1827, f Camb. Phil. Trans. 1820; Phil. Trans. 1825.
1 Phil. Trans. 1828.
244 Mr. Christie on the Permanence of
Finding that not only no change took place in this time,
but that in much longer intervals scarcely any appreciable
change could be observed, I was led to make observations
with the view of determining whether, during a very long
interval of time, the magnetism unequally distributed in a
steel bar would return to a state of symmetrical distribution.
For this purpose I made use of four bars of steel, which
had been somewhat softened, in order that they might be
reduced to the same thickness by filing, and which I had not
afterwards hardened, as I considered that with such bars
changes would be most likely to occur. These, for the sake
of distinction, I marked I., II., III., IV. Each of them is
0'15 inch in breadth, and 0*1 inch in thickness ; I. and II.
are 8'91 inches, and III. and IV. 5'94 inches in length.
I. and II. were placed by the side of each other, and strongly
and carefully magnetised by double touch, by means of two
twelve-inch bar magnets ; and the same was done to III. and
IV. As usual, the south pole of each was indicated by a
mark on that end of the bar ; and in order to avoid any am-
biguity which might arise from a change of position in the
bars, when I determined their magnetic centres and poles, I,
in all cases, made use of the terms, marked and unmarked
ends, instead of south and north poles. The magnetism of
I. and III. was disturbed by passing the marked end of a
twelve-inch bar magnet from their centres to their marked
ends twice ; and that of II. and IV. was disturbed by a similar
operation with the unmarked end of the bar magnet, from
their centres to their unmarked ends.
In order to determine the position of the magnetic centre in
each bar, I placed it on a rectangular wooden scale, parallel
to, and equally distant from, the sides, the scale being fixed so
that the axis of the bar was in the magnetic meridian, and its
marked end towards the north. A compass, with a small
trial needle, an inch in length, was fixed on another rectangular
piece of wood furnished with a vernier ; so that the scale being
graduated across to tenths of an inch, and the side of the
rectangle having the vernier being applied to it, the position of
the point of the magnetised bar opposite to the centre of the
trial needle could be determined to the hundredth of an inch.
The side of the rectangle carrying the trial needle and that
the Magnetism in Steel Bars. 245
of the scale being in contact, the former was passed along the
side of the latter, until the position of the trial needle was
exactly reversed ; that is, until its marked end pointed accu-
rately south : the point of the bar then opposite to the centre
of the needle, I considered as the zero, or magnetic centre
of the bar. The distance of this point from the centre of
figure of the bar was determined by passing the needle along
each side of the scale, and a mean of the two distances taken ;
and this distance. I designated M or U, according as it was
towards the marked or unmarked end of the bar.
The points in the bars towards which the small needle, if
uninfluenced by terrestrial magnetism, would be directed, when
near to them, and which are nearly those where the magnetic
intensity is the greatest, I considered as their poles ; arid in
order to determine their positions in each bar, the scale was
placed at right angles to the meridian, so that the marked end
of the bar was towards the west. The trial needle with its
vernier was then passed along the north side of the scale until
the position of the needle was exactly reversed ; and then again
until it assumed its natural direction : the point of the bar
opposite to the centre of the needle, in the first case, I consi-
dered to be its north or unmarked pole ; and that opposite to
it in the second, its south or marked pole. The distances of
the poles from the centre of figure of the bar were similarly
determined by passing the trial needle along the south side of
the scale, the needle being, in this case, in its natural direction
when opposite to the unmarked pole, and having its direc-
tion reversed when opposite to the marked pole. I took a
mean of the distances thus determined for each pole, as the
distance of that pole from the centre of figure, although I
considered that the position of the needle, when its direction
was reversed, was most accurately determined, since in this
case the slightest change in its position caused a very sensible
change in its direction. I should here remark, that in these
bars there were no indications of other poles besides those
whose positions I determined, magnetism of the same character
predominating from the zero, or near that point, to one end of
the bar, and the contrary magnetism predominating from the
same point to the other extremity.
The observations are contained in the following Table : —
Di-.tanrc by
Distance by
which the niMrc
which the less
Distance of
deteriorated
Distance by
deteriorated
Bar on
the mi-
uiarki'il or
I'M!,- receded
from, or the
Pittance of
he magnetic
ihich the mag-
netic centre ap-
Distance of
the. .Marked
Pole ap-
proacheu, or
which tin
Date of the
North 1'olc
less ill-lei lo-
centre or
proucheil the
or South Pole
the more ile-
OWrvu-
tions were
made.
Observations.
I'rom the
centre of
tiyure of the
Bin.
ratcd Pole ap-
proached the
centre, in the
interval be-
Zero from the
centre of
figure of the
Bar.
cntre ol li;;mc
ill the interval
between the
observation*.
from the
centre of
figure of the
Bar.
crioratccl Pole
receded from
the centre in
he interval be-
t\\eeu the nil-
tween the ob-
nervations.
servations.
1828, July 18.
Inches.
•24
•24
Inches.
2-18M
2-16
Inches.
4-24
4-28
Means
.24
2-17
4-26
1828, Sept. 18.
•26
•26
-|-0 -02
2-17
2-16
4-0-005
4-24
4-27
4-0-005
Means
•26
2-165
4-255
1828, Nov. 18.
•24
•28
0-00
2-16
2-13
+0-02
4-25
4-26
0-00
Means
•26
2-145
4-255
1829, Jan. 18.
•23
•31
4-0-01
2-15
2-14
0-00
4-25
4*28
-0-01
Means
•27
2-145
4-265
I.
1829, Mar. 19.
•23
•36
-1-0 -025
2-15
2-13
4-0-005
4-25
4-28
0-00
Means
•295
2-14
4-265
1829, May 20.
•26
•35
-i-o-oi
2-14
2-14
o-oo
4-25
4-28
o-oo
Means
•305
2-14
4-265
1829, July 20.
•30
•34
-i-0-015
2-14
2-14
0-00
4-23
4-29
-j-0-005
Means
•32
2-14
4-26
1830, June 3.
•35
•36
+0-035
2-14
2-12
+0-01
4»22
4-30
O'OO
Means
•355
2-13
4-26
1830, Dec. 2.
•30
•42
-f-0-005
2-13
2-09
4-0-02
4-25
4-26
4-0-005
Means
1-36
2-11
4-255
1828, July 18.
4-17
1-98U
0-88
4-17
1-98
0-92
Means
4-17
1-98
0-90
1828, Sept. 18.
4-17
4-17
o-oo
1-98
•99
-0-005
0-89
0-92
4-0 «005
Means
4-17
•985
0-905
1828, Nov. 18.
4-17
4-18
-0-005
•98
•98
-f-0-005
0-88
0-92
-0-005
Means
4-175
•98
0-90
1829, Jan. 18.
4-16
4-15
+0-02
•95
•97
-f-0-02
0-92
0-95
4-0-035
Means
4-155
•96
0-935
II.
1829, Mar. 19.
4-16
4-19
-0-02
•96
•98
-0-01
0-89
0-95
-0-015
Means
4-175
•97
0-92
1829, May 20.
4-16
4-19
o-oo
•96
•97
4-0-005
0-92
0-94
4-0-01
Means
4-175
•965
0-93
1829, July 20.
4-18
4-18
-0-005
•97
•96
o-oo
0-84
0-94
-0-04
Means
4-18
•965
0-89
1830, June 3.
4-16
4-17
-J-0-015
•98
•95
0-00
0-85
1-00
4-0-035
Means
4-165
•965
0-925
1830, Dec. 2.
4-10
4-16
+0-035
•61
•GO
4-0-36
1-70
1-71
4-0-78
Means
4-13
1-605
1-705
'Distance by
Distance by
which the more
whirh the lens
DiHtnncc of
ilrici iorii ted
Distance by
deteriorated
Bur on
which llu-
I >li~ci \a-
Date of the
tin- iiii-
markcd or
North Pol.-
from the
Pole receded
from, or the
It--* deterio-
rated Polo ap-
Distance of
10 magnetic
centre or
ero from tin-
vhi.h fur mag-
netic centre np-
proachcd the
L-ent.ro of figure
Distance of
the Marked
ir South Pule
1'rom the
Pole ap-
jjrnachcd, or
tin- more ilc-
i-rioratcil 1'olc
lions wen-
mail,-.
Observations.
centre of
figure of the
proached tbc
in the
interval be-
centre of
i^'inc of tlu-
in the interval
between tlu:
Observations.
centre of
figure of the
Bar.
nvi-ili-il from
the centre in
he interval be-
tween the ob-
twi-i-n the
»c-rvution».
Observations.
1828, July 18.
Inches.
0-76
0-78
Inches.
1-28M
1-27
Inches.
2-89
2-91
Means
0-77
1 -275
2-90
1828, Sept. 18.
0-77
0-78
+0-005
1-29
1-27
-0-005
2-88
2-92
O'OO
Means
0-775
1-28
2-90
1828, Nov. 18.
0-78
0-80
+0-015
1-28
1-26
+0-01
2-89
2-92
-0-005
Means
0-79
1-27
2-905
1829, Jan. 18.
0-78
0-80
0-00
•27
•26
+0-005
2-90
2-93
-0-01
Means
0-79
•265
2-915
III.
1829, Mar. 19.
0-79
0-86
+0-305
•27
•25
+0-005
2-89
2-91
+0-015
Means
0-825
•26
2-90
1829, May 20.
0-80
0-84
-0-005
•26
•26
0-00
2-89
2-92
-0-005
Means
0-82
•26
2-905
1829, July 20.
0-85
0-85
+0-03
•26
-25
+ 0-005
2-87
2-91
+0-015
Means
0-85
•255
2-89
1830, June 3.
0-80
0-88
-0-01
•26
•23
+0-01
2-85
2-93
0-00
Means
0-84
•245
2-89
1830, Dec. 2.
0-83
0-94
+0-045
•24
•20
+0-005
2-88
2-90
0-00
Means
0-885
•22
2-89
1828, July 18.
2-84
0-99U
•40
2-84
0-98
•47
Means
2-84
0-985
•435
1828, Sept. 18.
2-83
2-84
+0-005
0-97
0-98
+0-01
•40
•49
+ 0-01
Means
2-835
0-975
•445
1828, Nov. 18.
2-83
2-84
0-00
0-97
0-96
+0-01
•43
•49
+0-015
'Means
2-835
0-965
-46
1829, Jan. 18.
2-82
2-84
+0-005
0-97
0-95
+ 0-005
•47
•54
+0-045
Means
2-83
0-96
•505
IV.
1829, Mar. 19.
2-81
2-84
+0-005
0-95
0-95
+0-01
•47
•55
+ 0-005
Means
2-825
0-95
•51
1829, May 20.
2-82
2-84
-0-005
0-95
0-95
0-00
•50
•55
+0-015
Means
2-83
0-95
-525
.1829, July 20.
2-84
2-83
-O'OOS
0-94
0-93
+0-015
•48
•57
0-00
Means
2-835
0-935
•525
1830, June 3.
2-80
2-85
+0-01
0^95
0-90
+0-01
•48
•60
+ 0-015
Means
2-825
0-9^5
1-54
1830, Dec. 2.
2-79
2-86
0-00
0-93
()•!)!
-o-oi
1 • 5-2
1-55
-0-005
Means
2-825
0-935
1-535
248 Mr. Christie on the Permanence of
In order to compare these results, it is necessary to consider
the effects produced on the situations of the poles and magnetic
centre of a bar by the disturbance of the symmetrical distribu-
tion of magnetism in it. When a bar has been carefully mag-
netised by double touch from its centre towards its extremities,
the magnetic centre is very nearly in its centre of figure, and
its poles are very nearly at equal distances from that centre*.
If to either pole of such a bar the similar pole of a magnet be
applied, the effect will be, to drive the pole at that end nearer
to the centre, the other pole further from it, and the magnetic
centre towards the other end of the bar. At the same time,
the intensity of each pole will be diminished, but that of the
pole in the branch to which the magnet has been applied con-
siderably more than that of the pole at the untouched end ;
and in the former branch, the magnetism will likewise be less
concentrated than in the other, having nearly the same degree
of intensity over a considerable space. So that any tendency
in the magnetism of the bar to return to a state of symmetrical
distribution in the two branches, would be shewn by the
approach of the untouched, or more intense pole, and of the
magnetic centre towards the centre of figure, and the receding
of the more diffused pole from that centre ; and as, in the dis-
turbance, the effect is greatest on the positions of the magnetic
centre and the pole at the end to which the magnet has been
applied, so this tendency will be most conspicuous in the
change of position of these points.
In the foregoing table, the changes which took place from
one observation to another, in the positions of the poles and
magnetic centre, are exhibited in the fourth, eighth, and sixth
columns, the sign plus indicating that the change was in the
direction corresponding to the resumption of a state of sym-
metrical distribution of the magnetism in the bars, and the sign
minus that it was in a contrary direction. Now although the
changes in all the bars are, upon the whole, of the former cha-
racter, yet, as they are the reverse in some cases from one
* The bars I. and II. having been thus magnetised, the positions of these
points were —
Unmarked Pole. Zero. Marked Pole.
1 3-85 inches. 0-58 inch U. 3*71 inches.
II. , 377 0-00 3-73
the Magnetism in Steel Bars. 249
observation to another, and are besides but small, it is extremely
doubtful whether, notwithstanding the care taken in adjusting
the bars for examination and replacing them afterwards, they
were not due to accidental derangement, when the bars were
moved at the several times of observation, rather than to a
tendency in the magnetism to resume a state of symmetrical
distribution. Indeed it is possible that the needle made use of
to determine the positions of the poles and magnetic centre
may have slightly modified the magnetic state of the bar, at
each observation, since it was necessary, for this purpose, to
bring it within a very small distance ; and such influence it is
scarcely possible to prevent, especially in the case of rather
soft bars, as these purposely were.
The changes in the bars I., III., IV., are in general much
greater from July, 1828, to July, 1829, than subsequently, and
are the most indicative of the mutual action of the poles upon
each other, since the changes in the positions of the more dif-
fused poles are much greater than could have arisen from
errors of adjustment or observation ; but even these, admitting
them to be entirely due to such action, are so small, consider-
ing the time during which they took place, that the force which
produced them must have been almost evanescent as compared
with the coercive force of the steel.
In the bar II., the changes are extremely small from July,
1828,. to July, 1829, and also from the latter date to June,
1830, and, varying much in their direction, do not indicate
that they were caused by internal action ; but from June to
December, 1830, a decided change in the positions of the poles
and magnetic centre took place. This, however, I have no
doubt was entirely due to accident. When I removed this
bar in December, for the purpose of making observations on it,
in order to see which was the marked end, I incautiously ap-
proached a candle unfortunately placed upon a box containing
a very powerful magnet, and, from the small amount of all the
other changes, I have no hesitation in attributing the consider-
able change here observable to the action of this large magnet
upon the poles of the bar. Those who have not been exten-
sively engaged in delicate magnetical experiments can scarcely
be aware of the difficulty of guarding against such accidental
250 Mr. Brande on the Electro- Chemical
influence, when surrounded by apparatus which is a source of
disturbance. Independent of such disturbance, there can, I
think, be no doubt that the magnetism in these bars would
remain very nearly, if not precisely, in the same state for
almost an indefinite period.
We may therefore conclude, from these observations, that,
after the action of a magnet upon a bar which determines the
position of its poles, has ceased, if any effect is produced by
reciprocal action, the forces tending to produce this effect are
almost evanescent when compared with the other forces acting
upon the magnetism of the bar. Upon the whole, I am dis-
posed to think, that into whatever state the magnetism of a
steel bar may be placed by the application of a magnet to it,
almost immediately after the removal of the magnet, the inter-
nal forces are in a state of equilibrium, or nearly so ; and that,
therefore, whatever may be the arrangement of the magnetism,
it is, if not absolutely permanent, liable to scarcely any dis-
turbance from internal action.
Royal Military Academy, 27th Dec. 1830.
ON THE ELECTRO-CHEMICAL DECOMPOSITION OF THE
VEGETO-ALKALINE SALTS.
BY W. T. BRANDE, F.R.S., PROF. CHEM. R. I.
T AM not aware that any experiments have been recorded in
relation to the phenomena presented by the salts of the
vegetable alkaline bases, when subjected to the action of
voltaic electricity ; and as, under such circumstances, they
exhibit appearances identical with those of ordinary salts, a
further analogy is thus established between those curious com-
pounds and the other salifiable bases.
Shortly after the discovery of a method of obtaining morphia
in pure state, I remember that Sir Humphry Davy suggested
the possibility of its affording, when electrised in contact with
mercury, results corresponding with those which Berzelius had
observed in respect to ammonia : he thought that the nascent
elements of the morphia, as liberated by electrical decomposi-
tion, might, under such circumstances, effect a similar apparent
Decomposition of the Vegeto- Alkaline Salts. 251
amalgam of the mercury, and he spoke of the subject as
likely to throw some light upon the corresponding ammoniacal
combinations. He made, I believe, a few experiments upon the
subject, but the results were not as he expected, and they were,
nowhere, I believe, recorded.
Since that period the subject generally has acquired much
additional interest, by the discovery of several other bodies
appertaining to the same class, and especially of quinia and
cinchonia, the medicinal preparations of which have rendered
these substances so generally known.
I repeated the experiment of the electrisation of moistened
morphia and mercury, a globule of which, in contact with the
vegetable base, was rendered negative ; feebly at first, and after-
wards by a more powerful voltaic combination. The morphia,
I had reason to believe, was perfectly pure ; but although the
process was continued for a due time, in one instance exceeding
twenty minutes, I did not observe any change in the fluidity of
the metal, nor did it, on being transferred to a glass of pure
water, exhibit any action upon that liquid, or any appearance
of having united to foreign metallic matter.
Crystals of pure cinchonia reduced to powder, moistened,
and subjected in the same way to the action of negatively elec-
trified mercury, were equally inert, and exhibited no symptoms
of contributing anything metallic to the mercury.
When mercury was similarly electrised in contact with
quinia, moistened and placed upon a positive disc of platinum,
it exhibited, in the course of a few minutes, appearances
very different from those exhibited with it, when electrised
in contact with morphia and cinchonia; the metal became
filmy, and after a time appeared to acquire a tendency to a
butyraceous appearance, and evidently had its fluidity dimi-
nished. When transferred into a tall glass of distilled water,
a peculiar motion was perceptible upon its surface, and ulti-
mately some small globules of gas were liberated, and it
regained, though slowly, its usual aspect.
This experiment first led me to suspect that something like
a metallization of the elements of the quinia had been effected,
but I could not satisfy myself that it was reproduced by the
action of water on the globule, nor could I, by carrying on the
252 Mr. Brande on the Electro-Chemical
process of electrism for a longer time, produce a much greater
effect than ensued in the first five or ten minutes. Aware of
the influence which very minute quantities of foreign matter,
and especially of the fixed alkalies, or of lime, might have in
producing some such appearances, and more especially recol-
lecting the singular results of Mr. Herschel's experiments
upon this subject, it became important to ascertain the absolute
purity of the quinia employed. I therefore examined it with
this view, and found it entirely soluble in strong alcohol ; when
dissolved in dilute muriatic acid the solution afforded no traces
whatever of lime to the usual tests ; but on burning a portion
of the above quinia in a platinum crucible, and dissolving the
ashes in muriatic acid, traces of lime were readily recognized
in the latter solution. I treated the morphia and cinchonia
which I had employed in the same way, but in them no traces
either of fixed alkali or of lime could in any way be discovered.
I am, therefore, induced to refer all the appearances which quinia
exhibits to the obstinate adhesion of a very minute quantity of
lime, which I have not yet been able entirely to deprive it of.
The electro-chemical decomposition of the salts of the
vegeto-alkalies is very characteristic, in consequence of the dif-
ficult solubility of their bases. If, for instance, a solution of
sulphate of morphia be placed in the voltaic circuit, so as to
be decomposed between two plates of platinum, the negative
plate, if the solution be strong, becomes presently covered with
a white crust of morphia, which gradually falls off in films ; if
the solution be more dilute, the morphia falls in the form of a
white cloud from the negative conductor.
The appearances are nearly similar with the solutions of sul-
phate of cinchonia and of sulphate of quinia.
Supposing that some more decided results than those above
mentioned might be obtained by electrising mercury negatively
in contact of the soluble salts of morphia, cinchonia, and
quinia, the experiment was made with the respective sul-
phates of those alkalies, but no further appearances of metal-
lization ensued provided the salts were pure — whereas any
alkaline impurity, though in very minute quantity, gave the
same equivocal appearances as had been previously obtained
with quinia containing a little lime.
of the Vegeto- Alkaline Salts. 253
The appearances afforded by the electro-chemical decom-
position of these salts led to the question, how far the bases
might be discovered by the voltaic test in the infusions of
opium and bark ; but. when these are treated in the usual way,
there is no distinct separation of difficulty soluble alkaline
matter, as might have been expected, in consequence, probably,
of the multiplicity of substances that are present : nor is strich-
nine separable in this way from the infusion of nux vomica.
SOME OBSERVATIONS ON DR. ARNOTTS EXPLANATION
OF THE NATURE OF STAMMERING.
BY MARSHALL HALL, M.D., F.R.S.E., &c., &c.
T WAS much struck, in the first instance, with the simplicity
of Dr. Arnott's explanation of the defect in speech termed
stammering, in his interesting and popular work, entitled
* Elements of Physics.' I, however, soon perceived its fallacy;
and as this has not hitherto, I believe, been pointed out, it
may not be amiss for me to do so briefly in this place.
I will first copy Dr. Arnotfs view in his own words. That
gentleman states, that * * The most common case of stuttering
is not (as has been almost universally believed), where the
individual has a difficulty in respect to some particular letter
or articulation, by the disobedience, to the will or power of
association, of the parts of the mouth which should form it,
but where the spasmodic interruption occurs altogether behind
or beyond the mouth, viz., in the glottis, so as to affect all the
articulations equally. To a person ignorant of anatomy, and
therefore knowing not what or where the glottis is, it may be
sufficient explanation to say, that it is the slit or narrow open-
ing at the top of the windpipe, by which the air passes to and
from the lungs — being situated just behind the root of the
tongue. It is that which is felt to close suddenly in hiccup,
arresting the ingress of air, and that which closes, to prevent
the egress of air from the chest of a person lifting a heavy
* Elements of Physics; vol. ii. Part I. Appendix pp. v— viii.
VOL. I. FEB. 1831. S
254 Dr. Marshall Hall on Stammering.
weight, or making any straining exertion ; it is that also, by
the repeated shutting of which, a person divides the sound in
pronouncing several times, in distinct and rapid succession,
any vowel, as o, o, o, o. Now the glottis, during common
speech, need never be closed, and a stutterer is instantly cured,
if, by having his attention properly directed to it, he can keep
it open. Had the edges or thin lips of the glottis been visible,
like the external lips of the mouth, the nature of stuttering
would not so long have remained a mystery, and the effort
necessary to the cure would have forced itself upon the atten-
tion of the most careless observer ; but because hidden, and
professional men had not detected in how far they were con-
cerned, and the patient himself had only a vague feeling of
some difficulty, which, after straining, grimace, gesticulation,
and sometimes almost general convulsion of the body, gave
way, the uncertainty with respect to the subject has remained.
Even many persons, who by attention and much labour had
overcome the defect in themselves, as Demosthenes did, have
not been able to describe to others the nature of their efforts,
so as to ensure imitation ; and the author doubts much whether
the quacks who have succeeded in relieving many cases, but in
many also have failed, or have given only temporary relief,
really understood what precise end in the action of the organs
their imperfect directions were accomplishing.
* Now a stutterer, understanding of anatomy only what is
stated above, will comprehend what he is to aim at, by being
further told, that when any sound is continuing, as when he is
humming a single note or a tune, the glottis is necessarily open,
and, therefore, that when he chooses to begin pronouncing or
droning any simple sound, as the e of the English word berry
(to do which at once no stutterer has difficulty), he thereby
opens the glottis, and renders the pronunciation of any other
sound easy. If, then, in speaking or reading, he joins his
words together, as if each phrase formed but one long word,
or nearly as a person joins them in singing (and this may be
done without its being at all noted as a peculiarity of speech,
for all persons do it more or less in their ordinary conversa-
tion), the voice never stops, the glottis never closes, and there
is of course no stutter, The author has given this explanation
Dr. Marshall Hall on Stammering. 255
or lesson, with an example, to a person, who before would
have required half an hour to read a page, but who imme-
diately afterwards read it almost as smoothly as was possible
for any one to do ; and who then, on transferring the lesson
to the speech, by continued practice and attention, obtained
the same facility with respect to it. There are many persons
not accounted peculiar in their speech, who, in seeking words
to express themselves, often rest long between them on the
simple sound of e mentioned above, saying, for instance, hesi-
tatingly, " e I e think e you may," — the sound
never ceasing until the end of the phrase, however long the
person may require to pronounce it. Now a stutterer who, to
open his glottis at the beginning of a phrase, or to open it in
the middle after any interruption, uses such a sound, would
not even at first be more remarkable than a drawling speaker,
and he would only require to drawl for a little while, until
practice facilitated his command of the other sounds. Al-
though producing the simple sound which we call the e of
berry, or of the French words de or que, is a means of opening
the glottis, which by stutterers is found very generally to
answer, there are many cases in which other means are more
suitable, as the intelligent preceptor soon discovers. Were it
possible to divide the nerves of the muscles which close the
glottis, without at the same time destroying the faculty of
producing voice, such an operation would be the most im-
mediate and certain cure of stuttering ; and the loss of the
faculty of closing the glottis would be of no moment.
* The view given above of the nature of stuttering and its
cure, explains the following facts, which to many persons have
hitherto appeared extraordinary. Stutterers often can sing
well, and without the least interruption, — for the tune being
continued, the glottis does not close. Many stutterers also
can read poetry well, or any declamatory composition, in which
the uninterrupted tone is almost as remarkable as in singing.
The cause of stuttering being so simple as above described,
one rule given and explained may, in certain cases, instantly
cure the defect, however aggravated, as has been observed in
not a few instances ; and this explains also why an ignorant
pretender may occasionally succeed in curing, by giving a rule
S 2
256 Dr. Marshall Hall on Stammering.
of which he knows not the reason, and which he cannot modify
to the peculiarities of other cases. The same view of the
subject explains why the speech of a stutterer has been cor-
rectly compared to the escape of liquid from a bottle with a
long narrow neck, coming — " either as a hurried gush or not
at all :" for when the glottis is once opened, and the stutterer
feels that he has the power of utterance, he is glad to hurry
out as many words as he can, before the interruption again
occurs.'
This view of the subject is so far from being correct, that it
is quite plain that it is only in the articulation of certain letters,
that expiration is interrupted, and, even in this case, the
interruption is not in the larynx, the organ of voice, but in some
part of the mouth, or organ of speech. It will assist us in the
determination of the question, to take a review of the influence
which the natural articulation has upon respiration, or rather
upon expiration. It may be ascertained, by the simplest expe-
riment, that in the pronunciation of the short word BAT, we
adopt a mechanism, by which not only the different letters are
formed, but the respiration is twice completely arrested ; — and
that, in the pronounciation of the equally short word FAN, we
first interrupt the flow of the air through the nostrils, whilst it
is forced between the teeth and lower lip, and then intercept
the course of the air through the mouth, whilst we allow it to
pass only through the nostrils.
It is on their influence on the respiration, that I formed the
division and arrangement of the consonants, published in the
nineteenth volume of this Journal ; their sub-division was
founded on the respective mode or mechanism of their enun-
ciation. I divided them —
1. Into those, in the articulation of which both the mouth
and the nostrils are closed, and the respiration, of course, com-
pletely arrested :
2. Into those, in the enunciation of which the nostrils are
closed, but the mouth left more or less open, for the exit of the
air, which is compressed, but not interrupted, in its expiration :
3. Into those, not requiring even the nostrils to be closed,
and in the enunciation of which the air is still less compressed
in its course from the lungs : and,
Dr. Marshall Hall on Stammering. 257
4. Into those, in the articulation of which the expired air is
not interrupted, and scarcely impeded at all.
Of the first class, are
B D G*
p; T; K.
In tracing these letters into their sub-divisions, we may
observe, that the first pair are labials, being formed by the
lips compressed together ; the second pair are linguo-dentals,
formed by pressing the point of the tongue against the posterior
and upper part of the upper teeth ; and the third pair are
linguo-palatal, being effected by pressing the middle part of the
tongue against the palate. In all, the posterior apertures of
the nostrils are effectually closed by the pendulous vail of the
palate being drawn upwards, and accurately applied to their
posterior apertures. And of course, those persons whose
palate is perforated, or in whom the pendulous vail of the
palate is imperfect, as sometimes arises from disease, are more
or less incapacitated from pronouncing these letters, the expired
air being no longer intercepted, as it ought to be, in its course.
Of the second class, are
F S
y; theTHf; and z.
In the articulation of these letters, the posterior orifices of
the nostrils are required to be closed, whilst, in the first pair,
the compressed air is continually forced between the upper
teeth and under lip ; in the second, between the teeth and the
tongue ; and in the third, between the point of the tongue and
the anterior part of the palate.
From this view of the subject, it will be readily apprehended
how the substitution of D or T for the TH, by foreigners, is so
remarkable ; for it is no less than the substitution of a total
interruption, for a mere compression of the air, in its exit from
the chest.
Of the third class of letters, are
M; N; L; R.
In the enunciation of these letters, the expired air is only
very slightly compressed, the nostrils being left freely open.
It is for this very reason, probably, that these letters have been
* i, e. the hard G. f Hard and soft.
258 Dr. Marshall Hall on Stammering.
termed liquids, as flowing without obstacle. And it is by this
circumstance, principally, extraordinary as it may appear, that
the letter M differs from the letters B and P, for they are all
equally labial ; and that the letter N differs from T and D, for
they are all equally formed by placing the point of the tongue
near the roots of the upper teeth.
Of the fourth and last class, are
H; the Greek X; Y; and W.
In the enunciation of these consonants, the air appears to
be scarcely compressed or impeded in its exit at all. This
fact may, I think, account for the circumstance, that it has
even been doubted, whether the two last letters be really con-
sonants or not; and for the remarkable fact, that they cannot,
as consonants, form the termination of any word. Their me-
chanism is guttural, double dental, and labial, respectively.
These letters, preceded as they are in this arrangement, by
the liquids, lead us almost insensibly to the class of letters to
be next noticed, namely, the vowels.
These are so called, from having been supposed to relate to
the voice alone *. This, however, is obviously an error. The
different parts forming the mouth, or organ of speech, are not
less necessary to the enunciation of the vowels, than to that of
the consonants, or their function less appreciable, on carefully
making the experiment. Thus, the French U is entirely
labial; the letter E is dental; O, palatal; whilst the diph-
thong AW, and the vowels marked in the French language by
the circumflex (A), are guttural.
Now let any one carefully examine the effort made by the
stammerer in his attempts at the enunciation of these various
letters. It will be obvious that the malady is but an exagger-
ation of the natural effort. In attempting to pronounce the
letters of the first class, violent efforts are made, yet expiration
— articulation — is not effected ; but there is frequently, nay
generally, a peculiar noise heard in the larynx, although its full
enunciation is prevented by the action of the muscles of the
mouth. But if the letters of the second class are pronounced
with stammering, there is a perpetual hissing from the escape
* Blumenbachii Iiistitutiones Physiologiae, Ed. MDCCCX, Sectio IX.
Dr. Marshall Hall on Stammering. 259
of compressed air, in the case of the letters F and V, between
the lips, in that of the T H, between the tongue and upper teeth,
and in that of the letters S and Z between the teeth. In the
stammering enunciation of the letters of the third class, there
is frequently a state of laborious respiration. In all these cases,
then, it is plain that the larynx is open ; any considerable effort
applied to the parts concerned in the articulation of the first
class of letters, — the least noise, — the least escape of air, alike
demonstrate this fact. In the natural, and in the stammering
articulation, there is the same total or partial interruption of
the expiration, at the same parts, not of the larynx, but of the
proper organs of articulation , only in different degrees. Let the
larynx be really closed, which may be done after a little trial,
and it will immediately be discovered that stammering is, in
fact, impossible ; the effort made by the force of the expired
air against the parts of the mouth called into action in the
articulation of the first class of letters, — all escape of air, — all
noise, become totally interrupted.
I have just attentively watched the attempts of a stammerer
to articulate the various letters.
In the effort to pronounce the first class of letters, especially
the letter T, still more if two T's come together, as in the
words THAT TREE, the face became flushed even from
interrupted expiration ; yet there was, at every repetition of the
effort, a noise audible in the larynx, proving that this part was
unclosed.
In pronouncing the letters of the second class, a repeated
hissing noise was distinctly produced by the flow of the com-
pressed air, in one case, (F, V,) between the under lip and
upper teeth ; in the second, (TH,) between the tongue and
upper teeth ; and in the third, (S, Z,) between the teeth.
In attempting the articulation of some of the letters of the
third and fourth classes, and of some of the vowels, the breath
was sometimes lost, as it were, in a full and exhausting expi-
ration, altogether peculiar.
All these results prove that the larynx is not closed in stam-
mering, and indeed that its closure and stammering are totally
incompatible with each other. When expiration is interrupted,
2GO Dr. Marshall Hall on Stammering.
it is by the co-operation, the coadaptation, of parts anterior to
the larynx ; it is, in a word, not an interruption in the organ
of voice, but in that of speech. The paralysis of the laryngal
muscles could not, therefore, effect the good which Dr. Arnott
ingeniously supposes.
But would no evil really result from this paralysis of the
muscles of the larynx ? Would the ' loss of the faculty of
closing the larynx " really ' be of no moment' ? On the con-
trary, the accurate closure of the larynx, not by the epiglottis,
but by means of its own muscles, is essential to the act of
deglutition. This is demonstratively proved by M. Magendie, in
his interesting memoir, ' Sur 1'usage de TEpiglotte dans la
Deglutition.' The fact is further proved by cases of actual
paralysis of the laryngal muscles occurring in the human body,
and by the effects of inflammation and contraction, and of
ulceration, of the internal parts of the larynx, in inducing
defective deglutition.
The rule proposed by Dr. Arnott for remedying stammering,
does not attach itself exclusively to the view which that gentle-
man has taken of the subject. .On the contrary, the very same
rule was proposed by myself, in the paper to which allusion
has already been made; in the following words : — ' Let a stam-
merer observe this r|ile : always to speak in a continuous or
flowing manner, avoiding carefully all positive interruption in
his speech ; and if he cannot effect his purpose in this way, let
him even half sing what he says, until he shall, by long habit
and effort, have overcome his impediment ; then let him gra-
dually, as he may be able, resume the more usual mode of
speaking, by interrupted enunciation. I am persuaded, that
this is the principal means employed by those gentlemen who
have undertaken to correct impediments in the speech, and it
is, undoubtedly, the most rational. In addition to this rule,
let the stammerer endeavour to speak in as calm and soft a
tone as possible ; for in this way the muscles of speech will be
called least forcibly into action, and that action will be least
liable to those violent checks or interruptions, in which stam-
mering appears to consist. It would, of course, be irrelevant
to the object of this essay, to allude to those other principles
Mr. Ainsworth's Observations on Cleanliness. 261
connected with stammering, such as nervousness, of which it
would be necessary to treat, in an essay written expressly on
this important and interesting subject.'
I am persuaded that I need not apologize to Dr. Arnott for
this free and plain discussion of his views relative to stammer-
ing, our mutual object being the discovery and establishment
of truth.
OBSERVATIONS ON MR. RENNIE'S PAPER ON THE
PECULIAR HABITS OF CLEANLINESS
IN SOME ANIMALS.
BY WILLIAM AINSWORTH, ESQ.
TN the first number of the Journal of the Royal Institution, I
observe a paper on the cleanliness of animals by Mr. Rennie,
in which it is advanced upon the authority of Wilson, the
author of the American Ornithology, that the serrated structure
of the claw of the goat-sucker is employed as a comb to rid
the plumage of vermin — an erroneous opinion as to its use
having been held by Swainson, White, &c.
It is a fact, not generally known, that the claws of most
birds are used for similar purposes ; and thus birds which have
short legs, as the swift, are most infested by insects. The
expedients which birds characterized by short feet — the waders
which, from the inflexible nature of their legs, and the geese
tribe, from the opposition to scratching, offered by the mem-
brane extending between the toes, are put to, in order to get
rid of their vermin, are well deserving of attention, as illus-
trating the ingenuity of animals, and the curious provisions
made by nature for their cleanliness. When birds, by accident
or imprisonment, are deprived of the natural means of ridding
themselves of vermin,. they often fall victims to these attacks.
Walking one day along the shore of Holy-Island, off the coast
of Northumberland, I disturbed an ash-coloured sanderling
(Calidris Islandica, Step.), which flew heedlessly, and as if
injured. On shooting the bird, I found that it was covered
with vermin, more especially about the head ; so much so,
that the poor thing must have fallen a victim to their torment-
ing ravages : on further examination, I found that it had lost
262 . Mr. Christie on the Aurora Borealis
one of its legs, so that it was from its incapability to rid itself
of these insects that their extraordinary increase was to be
attributed. A circumstance of a similar kind also came under
my notice connected with a swallow's nest. After the young
birds had been hatched, and had attained a certain size, a
change was made in the arrangement of the window, which
frightened the parents : from that time they continued to feed
their offspring, but never entered the nest ; and I soon observed
that the young ones were sick, and one by one they perished.
I then took the nest down, and found it crowded with acari,
which were of a very great size compared with that of the bird
itself. I could only attribute this fatal increase of vermin to
the old birds having been prevented cleaning out the abode of
their family.
Poultry which run about in stony or paved yards, wear away
the points of their claws by friction and digging, which renders
them unfit to penetrate their coating of feathers ; they are,
therefore, more covered with vermin, and in consequence more
sickly than fowls from the country.
ON THE AURORA BOREALIS OF THE ?TH OF JANUARY, 1831.
BY S. H. CHRISTIE, ESQ., M.A., F.R.S., &c.
[To the Editor of Q. J.of Science, &c.]
Woolwich Common, 1th January ', 1831.
"YTDU will not, I think, be sorry to have some account of the
appearance of the very beautiful aurora of this evening,
in this neighbourhood, where, perhaps, I had a better oppor-
tunity of viewing it than you might have in town. I was not,
however, under very favourable circumstances for making
remarks upon it, as I was, for a considerable part of the time
during which it appeared, travelling, being outside of our coach.
I first observed it at 5h. 30m., being then on Blackheath,
about half a mile S.W. from the observatory. At this time I
observed a strong white light, resembling the tail of a comet,
but denser, like a light cloud illuminated by the moon, pro-
ceeding from near Betelguex in the east towards Aldebaran.
of the 1th of January, 1831. 263
It very quickly spread in this direction towards the south, and
was soon joined by a similar band of light proceeding from
(he west, the whole now forming a strongly-marked arch, about
5° in breadth, pretty well defined on the upper side, but not
so well on the lower. The highest point of the arch passed
over the planet Mars, about 45° above the horizon. Towards
the west the arch was lost in what appeared to be the London
smoke, about 10° above the horizon ; and towards the east,
about the same portion was lost in haze ; or rather it appeared
to proceed from the smoky fog at this height on the west, and
the haze on the east. The whole had the white appearance
of a thin cloud illuminated by the moon. The brightest parts
were to the S.E. and S.W. This arch faded gradually away,
but was visible for nearly a quarter of an hour. Before it had
disappeared, I observed a strong light in the N.E. (at this
time I was about three-quarters of a mile S.E. from the
observatory) of a brilliant rose colour. This increased rapidly
in brilliancy, and sent coruscations up to the zenith. Very
shortly afterwards the whole of the northern horizon became
illuminated, and brilliant coruscations shot from every part
towards the zenith. Some of these were very thin and well
defined ; but were not much tinged with red, excepting towards
the N.E. and N.W. At the same time large detached masses
of light, resembling floating clouds, were seen on the southern
side from east to west ; and similar ones, though not so strongly
enlightened, appeared towards the north. These, towards the
north, after a short time, assumed the appearance of an irre-
gular inverted arch, the lowest point being, as near as I could
judge, in the magnetic north, and brilliant coruscations pro-
ceeded rapidly from every part, some being slightly tinged with
red. Shortly after six o'clock, when I arrived here, these
gradually diminished in brightness ; and at half past six> little
more could be observed than a general light diffused over the
northern side of the heavens. At 7h. 30m. I observed a
distinct arch of light towards the north, the centre of the arch
being very nearly in the magnetic north, and its highest point
about 25° or 30° above the horizon. The eastern and western
ends of this arch, like that which first appeared towards the
south, were not visible near to the horizon.
264 Mr. Christie on the Aurora Borealis
8th January. — Later in the evening the northern arch in-
creased in distinctness, the upper circumference being very
well defined, and below there was another luminous arch, in
the interior of which was a dark segment 10° or 12° in alti-
tude. The magnetic north still appeared to be the centre of
these arches ; only very faint streams proceeded from the
upper arch. The strongest light was at the two ends, towards
the east and west. This was the appearance at 9h. 30m. ; at
9h. 50m. three concentric arches were distinctly visible, their
highest points being still in the magnetic meridian; at
lOh. 45m. there was a single broad well-defined arch in the
north, the lowest side of which, resting on the dark segment,
was particularly well defined. The appearance was, very shortly
after this, that of the dark segment breaking through the arch
of light in various places, and sending through it dark streams,
narrowing as they ascended. The luminous arch was now
soon broken up, when there appeared in the N.E. a stream of
pale rose-coloured light. The light in the N.W. shortly after
assumed the same colour ; and then the light in various inter-
mediate places was tinged with the same, that in the N.E.
becoming of greater intensity. Distinct pencils of light, stream-
ing upwards, appeared now to be propagated from E. to W. ;
and brilliant coruscations, tinged with red, proceeded from
every part. The phenomena were now nearly the same as at
six o'clock, but of very inferior brilliancy. The streams of
light gradually faded, and at llh. 20m. the luminous arch,
resting upon the dark segment, was formed as before, but the
streams of light were very faint. At llh. 45m. the upper side
of the luminous arch could be traced ; but the lower side was
quite broken, and there were no streams from any part. From
lOh. 45m. to llh. 45m. I observed the star Deneb (a Cygni)
very distinctly visible through the border of the dark segment,
but it was not visible after this. At llh. 20m. this star occupied
the highest part of the arc, which must, therefore, have been
about 10° in altitude^ and still nearly in the magnetic meridian.
The arch, though faint, was visible for some time after mid-
night ; and at six this morning, the whole of the northern
horizon was illuminated, and I thought the light somewhat
tinged, but the moan being up, rendered this doubtful.
of the 1th of January, 1831. 265
I regret much that I had not a magnetic needle so adjusted,
that I might have observed whether the aurora had any mag-
netic influence. As it is not improbable that we may have a re-
petition of the phenomenon, I shall take care to be prepared in
this way. I am not aware that, before this, any luminous
arch has been observed towards the south, in this part of the
globe, and I am very anxious to hear what observations have
been made on this arch farther to the south. Dr. Gregory is
at present at Hastings, and I intend inquiring of him, whether
an arch was observed to the south of that place ; if so, at what
elevation at 5h. 30m. ; and if not, whether the arch appeared
to the north at that time : its elevation at these two places
would pretty nearly determine its absolute height above the
earth's surface. As I saw them, the phenomena between five
and six o'clock, and between ten and eleven, were repeated
nearly in the same order: the strongest red light appearing
first in the N.E., and the coruscations succeeding the dis-
appearance of the luminous arch in both cases. The tem-
perature was rather low, but steady, about 24° F. during the
whole time ; the barometer high and steady (last night at
12h. 45m. 30-64 ; now 2h. P.M. 30-59).
ON THE MECHANISM OF THE ACT OF VOMITING.
BY MARSHALL HALL, M.D., F.R.S.E., &c. &c.
T WAS greatly interested by the following extract from the
valuable Report of cases in the Meath Hospital, just pub-
lished by Drs. Graves and Stokes, in the fifth volume of the
* Dublin Hospital Reports and Communications.'
* A man about forty years of age died of tubercular phthisis.
* The oesophagus, after passing through the usual opening
in the diaphragm, was found to re-enter the thorax by another
very large opening in the tendinous portion towards the left
side. The stomach occupied the inferior portion of the left
thoracic cavity, its cardiac and pyloric extremities both lying
in the opening.
' The man vomited frequently while under observation in
the hospital, Now, as the stomach was placed entirely out of
2GG Dr. Marshall Hall on the
the reach of being compressed by the contractions of the
diaphragm, and as this contraction completely defended it
from the influence of the abdominal muscles, it is clear that,
in this case, vomiting must have occurred independently of
compression, either of the diaphragm or of the abdominal
muscles. This fact, worth a thousand experiments, com-
pletely decides the question, that vomiting may be produced by
the action of the stomach itself, unassisted by any external
compressing force, notwithstanding what Le Gallois and late
physiologists have said to the contrary.'*
The authors of the report do not appear to have seen the
paper f which I published in the number of this Journal for
April to July, 1828 ; the object of which was — first, to expose
the fallacy, both of that view of the nature of the act of vomit-
ing, which refers it to a contraction of the stomach itself, and
of that other view lately advocated by M. Magendie, which
refers this act to the simultaneous contraction of the dia-
phragm and abdominal muscles ; and, secondly, to propose a
new view of this disputed question. As this last view has
never been controverted — as it has, on the other hand, been
generally admitted — and as it alone explains the various diffi-
culties which beset each or both of the other two — it may not
be amiss to reproduce its broad outlines here, in connexion
with the interesting case of Dr. Graves and Dr. Stokes. They
are these : —
1. During the act of vomiting, the larynx is closed ;
2. The diaphragm, and its various apertures, are relaxed ;
and,
3. All the muscles of expiration are called into action ; but,
4. Actual expiration being prevented by the closure of the
larynx, the force of the effort is expended upon the stomach,
the cardia being open from the relaxed condition of the dia-
phragm,— and vomiting is effected.
It is plain, from this view of the subject, that the thorax and
abdomen become one cavity, as it were, the diaphragm lying
loose and inert between them. It is also obvious, that it is
* Pp. 85—87.
t In this Paper I have referred to cases similar to that given by the
authors of the Report.
Mechanism of the Act of Vomiting. 267
quite indifferent on which side of the diaphragm the stomach
may be placed, whether above, as in the case of hernia, or
below, in its natural situation.
The view of the act of vomiting which I have taken, appears
to me to be the only one which at once explains this act, as it
occurs in the case of hernia of the stomach through the dia-
phragm, such as the one detailed by Dr. Graves and Dr. Stokes;
and the experiment of M. Magendie, in which a bladder was
substituted in the place of the stomach. The first establishes
the fact> that the diaphragm, the second, that the stomach,
has no necessary part in vomiting. It remained, therefore, to
shew in what other manner the act of vomiting, and both of
these facts, would admit of explanation. This is done in the
manner already detailed. And the truth of the explanation is
proved by two decisive experiments, related in the paper to
which I have already referred.
FURTHER EXPERIMENTS ON THE COMMUNICATION OF
PHOSPHORESCENCE AND COLOUR TO BODIES
BY ELECTRICITY.
BY THOMAS J. PEARSALL,
Chemical Assistant in the Laboratory of the Royal Institution.
TN a former communication (page 77 of the Royal Institution
Journal) I observed, that those phosphori which are distin-
guished for their property of evolving light when heated, and
which, under ordinary circumstances, allow of no repetition of
this effect, could have the property restored to them by the
agency of the electric discharge. I now purpose to offer some
additional experiments and remarks upon this induction of
phosphorescence.
From the results obtained, there was reason to anticipate that
not only all such phosphorescent bodies might have this pro-
perty modified, increased, restored, or imparted to them by
the agency of ordinary electricity, and the effects be alternately
produced and destroyed any number of times, but also that
268 Pearasll on the Communication of
bodies, not as yet known to possess this power, might have it
conferred upon them.
The restored effects which I have described, as produced
upon some known phosphori, in the former paper, I found to
occur with the class generally; and the following ordinary
substances will afford illustrations of the facility with which
phosphori may, as it were, be created in ordinary substances by
the means in question. The fragments used were placed in
the cavity of a piece of ivory, into which were inserted two
wires, and regulated discharges passed through them from a
Leyden jar, having about two square feet of coated surface.
The electrified portions were usually submitted immediately
afterwards to a strong heat, so as to exhibit the whole effect
of the phosphoric light with the utmost intensity.
White statuary marble yielded no light in its natural state ;
after twelve discharges it was heated on platina, and gave a
dull orange light.
The same marble, calcined at a red heat, and electrified by
twelve discharges, gave a clear orange and violet light by
heat.
The carbonaceous part having been dissipated from ivory
calcined, a lilac coloured light was conferred by fourteen dis-
charges of electricity. This substance was, however, feebly
luminous when heated in its natural state.
Mother of pearl calcined, and twelve times electrified, when
heated, gave a strong light of pink, violet, and light blue
colours, the whole of which were occasionally visible upon
different parts of the same fragment.
Calcined oyster-shells, heated, after fifteen discharges emitted
a strong light, of considerable duration, with orange, yellow,
and lemon-green colours.
Cuttle-fish bone calcined, after six discharges, was capable
of evolving by heat a bright lilac and violet coloured light ;
twelve discharges gave distinct pink, purple, arid yellow phos-
phorescent light.
Common scollop shells were calcined and subjected to twelve
discharges of electricity : the application of heat disengaged a
strong light of considerable permanence, blending salmon, j)inkt
Phosphorescence and Colour by Electricity. 269
and intense azure blue tints. The phosphorescence of these
specimens had light and colour of exquisite delicacy.
Chalk gave an orange light, rather dull, when heated in its
natural state ; but if made red hot, allowed to cool, and then
twelve times electrified, it evolved a bright orange light when
heated.
Common egg-shells gave no light ; but twelve discharges of
the electrical jar conferred a bright purple light.
The preceding experiments were made with substances which
did not possess this peculiarity in their ordinary state, yet exhi-
bited the conferred phenomena, with such beauty, variety, and
intensity of colour, as to surpass very many natural specimens.
The results obtained with such varieties of fluor spars as I
had access to, appeared in a tabular form in my preceding
communication ; the examination of other specimens presented
similar effects.
The probable localities of the following varieties of fluors
have been assigned by Mr. Sowerby : —
[The natural phosphorescence is shown in the second column ; the third column
states the number of explosions sustained by the calcined mineral, and also the
phosphorescent appearances by heat subsequently applied.]
16 to 12, a bright green, ending
with purple.
36. The green is increased nearly
to the intensity of the natural
phosphorescence of chloro-
phane.
2' S3£«5£±fe f » *> 40. First,,,*, A
from Wear-dale f^W blue and Pw'Ple • ' \ Vlolet and sh'OH3 Pu
Cumberland ...... J I very Beautiful.
3. Pale
ale yellow cubic). . .. .... J12, 24 36. Yellowish light of
fluor (Gersdorfl") I Green and uio/e/ light. .< short duration, terminating
[ with purple.
ubic fluor (palel f . ,. . [12. Green and rich purple lidit-
green) from Cum- \Llfli ?™en> changing I 24 Grem and rich/,«r,>/e light,
berland ......... J to Vink ™d molet' ' ' \ ending with orange colour^
•j f!2. Green and rich purple light.
>Rich purple .......... < 36. Green light and other tints,
[ rapidly changing.
5. Cubic fluor (pale
green) Cumberland
most white.
12. A fragment emitted intense
light, pale greenish tint, al-
50. Intensely rich green liyht of
short duration.
7. Crystalline massive ( Dull green and pink, of V, , Yellou>i
light ......... \ pie ................. \ pie, good light.
Strong yellow andj Pale yellow, green, violet, ~\ Tints of yellow, orange, pale-
greenish colour. \ a.nd purple^ strong light/ green, and purple.
" d'ribt •
6. Yellow and orange Yellow ............... Strong light, yellow and orange.
7-
8. Yellow light, cori-la, ,. , , , ..
fined to spots. . JStrong hgH Pale S«*>w • G™™ and violet.
9. No light ....... Chiefly feeble purple light Fleeting tints of purple.
T2
272 Pearsall on the Communication of
N After 21 days in After 21 days in Portions kept in the dark
Light. Darkness. for three months,
10. No light Green and purple light . . j
11. Very feeble on I™ • ... v •»
some portions lCha.nSmS ^nis' ending!
only ••••••*••!
12. Faint light ..... ^^' eof *} Yellow ^i purple light.
Dark green and \Brighter green, remained with Apatite, which also has been
yellow tints . . . / calcined and electrified.
It appeared that during twenty-one days' exposure to sun-
light, that the portions of Nos. 1, 5, 11, and 12, lost nearly all,
and Nos. 9 and 10 all their phosphorescence ; also, that
Nos. 1, 4, 6, 7, 8, and 12, had the colours modified during the
time of exposure, as compared with their phosphorescence given
in Table 1 : orange and purple tints seem to be assumed by time.
The third column gives the phosphorescence conferred by
electricity, which remained after an interval of nearly three
months.
The effects detailed in this and in my previous communi-
cation are those produced after the destruction of the phospho-
rescence, which naturally existed in the minerals, by the appli-
cation of a strong heat : another class of effects are now to be
introduced, resulting from the electrization of bodies still retain-
ing their native phosphorescence.
The result of this obvious extension of the inquiry was a
series of magnificent colours, and an exaltation of the original
phosphorescence, of which it is very difficult to convey an idea.
Crystals of the FLUORS, whose localities are given in Table 1.
(p. 269), were used in the following experiments, upon the induc-
tion of additional phosphorescence by electricity. The same
order of the substances is preserved in the present table.
No. of Heated to decrepitation — colour
Minerals. Colour of Natural Electrical of superinduced Phosphoric
Phosphorescence. Discharges. Light.
1. Green fluor. ~| (Green, bright blue, intense rich
Yellow green \Pink and orange.. 24 \ purple, with after tints of pink;
portion . . . J [ very strong light.
Bluish green j1^' nearly white, 1 , yi id emcrald reen then ur_
f Intense purple, several portions
gave deep orange light : after
2. Green fluor...(CoWV,MMamll 20 \ it had been heated to redness
purple light.... J j for some timej it was stm
luminous with a bluish light.
Phosphorescence and Colour by Electricity. 273
No. of Heated to decrepitation— colour
Minerals. Colour of Natural Electrical of superinduced Phosphoric
Phosphorescence. Discharges. Light.
, 7,. ...... ., ,. ( Lemon-yellow, violet, and seve-
3. Yellow fluor..ratherl 16 { ral colours changing during
[ decrepitation.
.bl
4. Light
fluor
greenfPale green,
.8. .. an
6. Dark purple ( Green, pink, purple, )
fluor ...... 1 and orange ..... J
7. Dark fluor
~ . , , . ,
{ tints }
* IH S .......... ^
8. Dark fluor
Faint
andl
J
9. Cuhic
fluor
violet
16
29
14
12
10
\ Green
{
^raw-yellow purple,
and several other
f Dark green, lemon- yellow, pur-
ple, and orange; the light
j from some portions was very
I strong, and nearly white.
{Peculiar intense light of straw
whiteness, then greenish, dull
orange, and pink tints.
11 rrPPnflnnr
01
and omn^e- )
ye//ow; ......... /
Compact darkly d
purple fluor . J
Apatite ( phos- ( Brilliant yellow-
phate of lime)\ yree/» .........
\ pink, and orange colours.
("Intense azure-blue, (some yel-
\ low,) very vivid light nearly
I white, from points of the
fragments.
( Brilliant emerald-green, violet
I and orange, very strong light,
j finally faint purple ; these were
I striking changes.
12
f Green yeltow, pink, and orange
\ light.
( Green, yellower, olive and orange
I tints, very strong light.
The additional phosphorescence appears to differ in colour
from the natural quality, and to be evolved at a lower tempera-
ture, and blends into the previous natural phosphorescence,
which also is increased in strength and duration.
These experiments may suffice to show that minerals, which
naturally are phosphorescent when heated, do not necessarily
exhibit the maximum degree of this peculiarity, but may have
it exalted by artificial means. The phenomena are so far
increased, that specimens of fluor, which held dull or unde-
fined phosphorescence, have been rendered, by electricity,
equal to the most eminent class of phosphorescent fluors;
some varieties, indeed, rivalling the intensity of chlorophane,
or Siberian fluor. The means of increasing the natural phos-
phorescence in bodies has not, as far as I know, been here-
tofore pointed out.
Portions of these electrified minerals were kept in darkness,
274 Pearsall on the Communication of
and examined after a lapse of fifty days. They still possessed
increased phosphorescence : in some the order of tints was
still the same; in others a change was observed, and the
orange tints evidently prevailed.
On the Influence of Structure upon Phosphorescent Bodies.
As the mineral phosphate of lime, called APATITE, possesses
naturally an intense degree of phosphorescence, other forms of
this chemical compound were experimented with.
Phosphate of lime was precipitated by alkalies from solution
in muriatic acid : it was collected, and allowed to aggregate by
carefully drying it ; the temperature was afterwards raised, but
there was no appearance of light. It was then calcined : small
compact hard lumps and powder were electrified by twenty
discharges from two feet of surface, but no phosphorescence
was induced.
Apatite was in like manner dissolved, precipitated, dried,
calcined, and electrified, but no phosphorescence was induced.
Phosphate of lime calculus was electrified and heated, rib
light appeared : being calcined to redness, twelve discharges
were made ; the fragments when heated evolved differently
coloured light; the yellow, green, and orange colours were
increased by twenty discharges, the light also being rendered
stronger. It is evident that change of texture would result
in this case by the destruction of the organic matter diffused
through the earthy mass.
As these bodies might be regarded as identical in chemical
respects, their great difference in phosphorescent power is due,
in some way, to the mechanical condition of the bodies : cohe-
sion, arrangement of particles, texture, and extent of surface,
are all circumstances which may influence the result.
The solidity of fluor spar was destroyed by levigation, but
phosphorescence was evident when the powder was heated.
Crystallized fluor spar (fluoride of calcium) was powdered
and dissolved in muriatic acid, from which it was preci-
pitated by ammonia, then dried, and calcined at a red heat,
without exhibiting light. Electricity also did not confer
phosphorescence.
Phosphorescence and Colour by Electricity. 275
This muriatic acid solution deposited after some time small
fragile crystals of fluoride of calcium ; these, when collected
and dried, lost their form ; when heated, they slightly decre-
pitated, and were phosphorescent.
There are certain classes of bodies which exhibit decided
differences in this relation to light. All the calcareous mine-
rals, as the carbonates of lime and the fluor spars, may be ren-
dered phosphorescent, while none of the specimens of quartz,
siliceous, and aluminous minerals resorted to, either possessed
naturally, or would receive phosphorescence.
I ought to mention, that in several instances I have observed
a slight return of phosphorescence by time after it has disap-
peared. One example was in a crystal of fluor spar which had
been calcined entire : after it had been deposited in darkness
for some months, it was found to have regained feeble phospho-
rescence ; and others, which gave no signs of light when heated
after the calcination, yet appeared luminous when heated after
a long seclusion from light. Other substances, besides these,
might be adduced, whose feeble but constant phosphorescence
cannot be the result of accidental circumstances alone. Com-
mon scollop-shells seem to inherit a remarkable phosphoric
structure, as also the substance of calcined oyster-shells and
cuttle-fish bones, especially when exposed to light for a short
time; instances have occurred, when, after a strong calcination
-of these substances, they appeared visible, although they were
heated many times and kept in darkness. These degrees of
luminosity, although not likely to be confounded with the pre-
vious experiments, are yet pointed out, because they were
guarded against in the following experiments. After all, the
effects of temperature may be far more influential than can
be traced at present, being perhaps as capable of disposing
structure, as requisite in the ultimate development of the phe-
nomena.
From these assigned reasons I conclude, that phosphores-
cence is dependent upon and modified by the structure and
mechanical conditions of the substances under investigation.
The beautiful results thus produced by electricity naturally
led me to vary its mode of application ; and as, in the expe-
riments described, the electric discharge had been passed
directly over the substances, I now inclosed them in glass
276 Pearsall on the Communication of
tubes, with the view of deducing, if possible, the proportion of
effect due to radiant matter passing off from the sparks : I found
that phosphorescence was effected, although glass intervened,
as the following facts will prove.
1. Portions of calcined scollop and oyster-shells were her-
metically sealed up in small glass tubes placed within a longer
tube, and the electric discharge effected its passage over the
outsides of these little tubes.
After one hundred and sixty discharges of a jar, these sub-
stances were found, when heated, to be phosphorescent. •
2. Six small tubes, sealed at both extremities, containing
calcined chlorophane, calcined cuttle-fish bone, and calcined
scollop-shells, were introduced into a glass cylinder, open at
both ends : large shot were rolled in to keep the small tubes
together, and to conduct the electricity.
This glass cylinder was then introduced into a glass tube of
larger diameter, the space between being filled with portions
of calcined oyster-shells and different fluors ; the glass cylinders
were placed horizontally.
Two hundred and twenty-five discharges of ajar were then
made through the inner tube ; the fragments contained be-
tween the two cylinders were decidedly phosphorescent when
heated.
The tubes which had been thus strongly electrified had their
contents examined.
The chlorophane fluor in two tubes was not phosphorescent.
The calcined oyster-shells had acquired an orancje-pink and
bluish light.
Other two tubes had calcined scollop-shells, which instantly
gave, when heated, a flame-coloured phosphorescence, with pink
and purple colours.
These experiments were necessarily very laborious ; fewer
explosions produced degrees of the effects ; but I did not feel
satisfied with giving the less decided results of thirty or forty
explosions. The two experiments, given above, required about
3000 revolutions of a large cylinder machine in good action.
I then resorted to voltaic electricity, as a source of phos-
phorescent power, although, at first, any effect might be sup-
posed to be precluded, either by the insulating power of the
mineral, or when the quantity and the intensity of the electricity
Phosphorescence and Colour by Electricity. 277
were increased : for, unless the intense heat at the interrup-
tion of the circuit were avoided, it would destroy the phospho-
rescence which might be produced by the vivid light and con-
tinuous current.
Portions of calcined oyster and scollop-shells were sub-
mitted to the voltaic light from points of charcoal attached to
the extremities of a voltaic battery in good action, of a hundred
pairs of four-inch plates ; the discharge being repeatedly in-
termitted, so as to resemble a series of ordinary sparks, guard-
ing against the elevation of the temperature of the tube and
the inclosed fragments. After ten minutes' exposure, they
seemed to have acquired phosphorescence through the glass ;
for, when heated, they appeared faintly luminous.
Common calcined purple fluor did not appear affected by
close proximity to the voltaic discharge.
Calcined oyster-shell powder, exposing a large surface to
the direct light, was phosphorescent when heated.
Calcined purple fluor was placed in a tube, the voltaic dis-
charge likewise effected in the tube over and through the frag-
ments, which were thus influenced by the voltaic discharge and
currents, from charcoal and from metal poles, but no phos-
phorescence appeared when the substance was heated.
A silver capsule, forming the termination of one pole, was
strewed with calcined fluor spar ; the charcoal extremity of the
other pole traversed the metal plate, causing sparks and silent
discharges to pass repeatedly through the portions of mineral ;
but the fluor was not luminous when heated.
Calcined scollop-shell, by the same arrangement, was ren-
dered phosphorescent upon the subsequent application of heat.
So that there are great differences with respect to the induc-
tion of phosphorescence in these bodies by ordinary and by
voltaic electricity.
On the Colouration of Fluor Spars by the Action of Electricity.
It was announced in the former communication, that certain
fluor spars, rendered white by calcination, became coloured
after they had been electrified — a distinct blue colour appear-
ing upon specimens which originally were deep purple. As
the cause of colour in these minerals has often been a subject
278 Pearsall on the Communication of
of chemical investigation, I maybe allowed to give some expe-
riments, which present this subject in a new point of view.
The fluors are those used in the former experiments upon
phosphorescence ; they were all rendered white by heat.
Green fluor from Cornwall, after calcination, was colourless,
nearly transparent, and in very small splinters, which obtained
a pink tint after thirty-two discharges of a large jar.
Crystal of No. 2, in the first Table, appeared naturally pale
green by transmitted light, but blue by reflected light ; heated
to redness, it became colourless and opalescent : forty dis-
charges caused blue tints upon the edges.
Large lemon-coloured crystal of fluor was opaque white
after calcination ; thirty-six discharges produced decided blue
and lilac colours.
Cumberland cubic fluor (No. 5.) was purple by reflected
light ; the white opaque calcined fragments were rendered
decidedly pink by thirty-six discharges.
No. 6. The purple cubic fluor from Berealston, Cumber-
land, when viewed by transmitted light, showed bands of blue
and violet ; by calcination a difference in structure was evi-
dent, by the alternating opaque planes : fifty discharges gave a
faint blue to some portions only.
Dark purple fluor became white by calcination, and received
a bluish tint by twenty-four discharges.
Twelve discharges rendered No. 8 bluish ; sixty electrical
explosions upon the calcined fluor caused it to appear blue.
No. 9 was opalescent by calcination ; it acquired a faint
pink tint by twenty-four discharges of electricity.
These various tints preclude the idea of fallacy, from the
deposition of foreign matter by the electrical discharges : in
one experiment, when nearly one hundred discharges had
been made over fragments, and metal was deposited in the
track of the discharge, it still preserved its metallic lustre.
Hence there appears every reason to conclude, that the colour
induced is the effect of structure alone.
These tints so produced were not permanent; some portions
in the light lost all colour in a few days ; other portions, kept in
darkness, showed these external tints after two months.
The pink tints are strongest upon the edges, and soften
upon the planes.
Phosphorescence and Colour by Electricity. 279
The blue tints are strongest upon the angles of the frag-
ments, and upon the solid angles of the fissures.
And I may call attention to a similar distribution of colours
to be observed in large crystals and specimens of massive
dark purple fluor, which have their colours unequally con-
ferred upon the surface, some portions being nearly white,
other parts having faint tints of violet, purple, or blue ; while
towards the edges and solid angles of the crystals, the colours
increase to intensity.
If massive dark fluor be broken into fragments, some of
those may be selected which are scarcely tinted, except upon
the edges and surfaces of the differently crystallized portions
just separated, and upon these parts intense colour resides.
I took a large mass of purple fluor, weighing several pounds,
and a portion was broken from a large cubic crystal, which
was deep purple in the solid edges and angles, while the
internal part near to the centre of the external planes was
nearly white, the crystals having a mottled appearance ; the
white portion was highly phosphorescent : calcined in a crucible
to redness, and subjected to electricity, no colour was pro-
duced, although it became highly phosphorescent.
Fluor spars with different colours were electrified in their
natural state, but no alteration or addition of colour was
remarked, excepting the dark purple fluor, whose depth of
tint was increased.
It is a curious circumstance, that those portions of fluor
which are naturally the most coloured, are also, when ren-
dered white by heat, recoloured with the greatest facility by
electricity; and as the latter power would appear to confer
colour only by modifying in some way the arrangement of the
particles, may not natural fluors owe their colours to structure?
And may we not be allowed to suppose that nature used the
same means, and that ELECTRICITY confers colour and phos-
phorescence in the first instance ? Both the natural and the
induced colours are destroyed by heat ; and the colour, like
the phosphorescence, may be repeatedly restored by electricity.
I may now, perhaps, venture to draw the following con-
clusions from the experimental details advanced, which have
proved electricity to be efficient in the restoration of phospho-
rescence.
280 Pearsall on the Communication of
From the very feeble phosphorescent effects obtained by
exposing substances to the intense light of the discharge, and
also to the constant current of voltaic electricity, it is inferred
that light, and great quantity of electricity, are not essentially
necessary, but that the effects are due to electricity of great
intensity, and hence the influence of the discharges of ordinary
electricity.
As electricity itself does not permeate glass, the effects upon
substances hermetically sealed up may be thus explained :
when the outsides of the glass tubes are electrified by the
intenseness of the discharge, a corresponding state is simul-
taneously induced upon the interior surface, and the con-
tiguous substances are rendered phosphorescent by the so
excited electricity.
The colours of bodies, generally, are believed to be due to
peculiar structures capable of decomposing light, and reflecting
particular coloured rays.
Since by experiment I have shown that colorific structure
obtains in certain varieties of colourless fluors, as the result of
intense electrization; and as electricity, under various con-
ditions, manifestly commands the relations of molecules and
masses of matter, by effecting, destroying, or suspending their
combinations, may it not be advanced, that when matter
(such as calcined fluor) which is not phosphorescent, is ex-
posed to electric discharges, that they cause vibrations of the
particles, which, being repeated with every discharge, gradually
modify the structure, and bring it into a peculiar state ?
May not the action of heat allow this state to return to what
it was originally ; and from the vibrations of the atoms of
matter in changes of structure proceed the undulations fitted
to produce light?
This explanation appears to me to be in perfect conformity
with the received laws and actions of light, heat, and elec-
tricity ; and also with the conditions of the earthy substances.
Other causes, competent to these alternating changes of
structure, may exist besides heat and electricity, but the above
view seems to apply to the phenomena of phosphorescence
generally. The alteration of phosphoric colours after some
time may be regarded as consequent to the variations of
atmospheric temperature having been sufficient so far to alter
Phosphorescence and Colour by Electricity. 281
the position of the particles, that when heat is ultimately
applied, the vibrations produced are fewer and comparatively
weaker.
Note. — Since my previous communication, I have been
informed of a work devoted to phosphorescence, and also of
an article in Gmelin's Chemistry, both in the German lan-
guage*. On referring to the abstract contained in parts of
the latter work, it appears that electricity has been employed
with phosphori ; and that certain bodies, phosphorescent by
heat, whose property had been destroyed by calcination, had
the property restored by electric shocks : any doubt upon the
subject might perhaps be decided by consulting the original
authority. My attention has also been called to some experi-
ments by Mr. Skrimshire (Encycl. Metrop., Art. Electricity,
§. 177), in which transient phosphorescence was conferred upon
different substances by drawing sparks from them, or passing
electrical discharges over them. The eyes were kept closed
until the sound of the discharge was heard, and the light then
observed. I am not acquainted with the detail of these
experiments, and my own train of investigation was conducted
independent of them, and was nearly concluded before I be-
came aware of any similar inquiry.
ON THE DARKNESS BETWEEN THE PRIMARY AND
SECONDARY RAINBOWS.
BY MR. AINGER.
[In a Letter to M. FARADAY, Esq., F.R.S., &c.]
MY DEAR SIR, 10, Doughty-street, Oct. 1830.
TN consequence of your remark a few days since, that you
had not seen a satisfactory explanation of the darkness
between the primary and secondary rainbows, I have referred
to several of the most accessible works on the subject, and I
find that the phenomena of the rainbow are in general very
imperfectly, and in many cases very incorrectly, described. I
do not discover that the darkness in question, though suffi-
ciently obvious, is ever alluded to ; nor does it appear to me
* Placidus Heinrich, Phosphorescenz derKorper, vol. iv. Gmeliu's Handbuch
der Chemie, part i.
282
Mr. Ainger on the
that its existence is easily deducible from the descriptions
usually given of the circumstances under which the rainbow
is produced.
I will not occupy your time with an enumeration of the
various mistakes which seem to exist on this subject, but refer
you at once to the Traite de Physique of M. Biot, whose
description and analysis, as far as I am able to appreciate
them, are the best I have seen. I think, however, with great
deference, that even these are, to a certain extent, imperfect
and incomplete. M. Biot says—
* The phenomenon of the rainbow is produced by the coloured spectra
which issue from different drops of water after two refractions, separated
by one or two intermediate reflexions. But how,' he proceeds, ' does the
superposition of these partial spectra compose the colours of the bow
and determine its magnitude ? This is what we have to examine.
* To do this simply, let us first consider a single incident ray of simple
colour — for example, red ; then, supposing that it emerges from the drop
after a certain number of reflexions and refractions, let us calculate the
angle it forms with its primitive direction.
' Let S I, Fig. 1 . be such a ray entering at I and escaping at I' after a
N.
Fig. 1.
second refraction, without intermediate reflexion. From the centre of
the globe draw C I N, C I' N', which will be perpendicular to the sur-
face. Then SIN will be the angle of incidence, which we will call i ;
and C 1 1' will be the angle of reflexion, which we will call r. Further,
in consequence of the symmetry of the figure, the interior incidence at I'
will also be r, and the emergence will be i. Prolong the incident and
emergent rays till they meet at T, forming the angle I T I', which will be
the deviation produced by refraction; we will call this A, Now it will
be easy to find its value in functions of the angles i and r ; for in the
quadrilateral C I T I', all the angles are known, except A. In short, the
angles at I and I' are both equal to i ; further, the triangle C 1 1' being
isosceles, the angle I C I' is equal to 180° -2 r ; then, since the sum of
the angles of a quadrilateral are equal to four right angles, we have
A + 2 i + 180» - 2 r = 2, 180«, or A = 180° +27'- 2 i.
Phenomena of the Rainbow.
283
* Let us next consider two refractions separated by one reflexion ; the
same construction (see Fig. 2.) and reasoning will apply : only the angle
Fig. 2.
I C I" will be double I C I', that is, equal to 2 (180° - 2r) ; thus we
have A + 2 i + '2 (180° - 2r) = 2, 180°, and A = 4 r - 2i.
' Generally, if the ray have n successive incidences in the interior of
the globe, the angle I C I" becomes n (180° - 2 r).
' The angular deviation will be constant for all rays of the same
nature, which penetrate the globe under the same incidence ; but the
incidence changing, that also will change. To form a clear idea of these
variations, let us first consider the case in which the ray suffers but one
internal reflexion ; after which it escapes from the globule into the air.
Then, if we calculate the amount of deviation for several parallel rays,
incident at small distances on various parts of the surface, it will be
found that the deviation is nothing under a perpendicular incidence, in
which the ray passes through the centre of the globule. The deviation
gradually increases to a certain limit of incidence, which is about 54£°
for the red rays, so that a pencil of these rays entering parallel at
I (see Fig. 3.) under this incidence, and being once reflected from
Fig. 3.
the inner surface, will emerge equally parallel at I", though the general
direction of the pencil be deviated 42°. But for more considerable inci-
dences, the deviation diminishes as it had increased ; and this diminution
284
Mr. Ainger on the
continues as far as the last rays tangent to the globule. Now if these
rays are received at such a distance from the globule, that this last may
be considered as a point, it is clear that all those which belong to unequal
deviations will diverge one from the other, as their distance from the
globule increases ; so that they will become too feeble to give a percep-
tion of the globule to an eye placed in their course ; while that eye would
be affected even at the same distance by the emergent rays, which cor-
respond to the maximum of deviation, because, being parallel, they are
transmitted to any distance without separation.
' Suppose a series of these globules disposed circularly in such manner
that the refracted rays which issue from them, and which are supposed
to be of the same colour, may thus reach the eye ; they will produce the
sensation of a luminous line ; and several such series placed side by side
will produce a coloured band.
' The same considerations apply equally to the cases in which the
refractions and reflexions are more numerous ; there is always for each a
limit at which the rays of a small pencil will emerge sensibly parallel, and
will be transmitted without becoming enfeebled.
* To develop the consequences of these results, suppose that an
observer placed at 0 (Fig. 4) views a large cloud composed of spherical
drops of water ; draw from the centre of the sun through the eye the line
S O C, to designate the direction of the rays, which we will for the present
suppose to be exactly parallel; as would be the case if the sun were a
Phenomena bf the Rainbow. 285
point infinitely distant. This being granted, there will be, from the ante-
rior surface of the drops, a partial reflexion of all the colours which com-
pose the incident light, and which will form a whitish tint, spread over the
whole surface of the cloud ; but, besides this, there will be seen two con-
centric arcs, coloured with all the colours of the spectrum. For if through
the eye O be drawn a right line O V, forming with O C an angle of
40° 17', and that it be supposed to revolve round O C, describing a
conical surface, all the drops which are found in this surface will have
the position in which the most refrangible violet rays, after having
suffered two refractions and one reflexion, will emerge parallel, and will
reach the eye at 0, and this will not take place in any other part of the
cloud ; in virtue, therefore, of these rays alone, the spectator will see
upon the cloud a violet bow, of which O C will be the axis, and O the
centre. There will, in like manner, be an infinite number of concentric
arcs exterior to the last, each formed by one description of simple rays;
and as the rays become less refrangible, their arcs will be of larger
diameter, so that the largest, composed of the extreme red, will subtend
an angle R O C of 42y 2'. Thus the total extent of the coloured band
will be 42° 2' - 40° 17', or 1Q 45', the red being without, and the violet
within.
' It will be the contrary after two reflexions. If the lines O R', O V,
be drawn, making with O C angles of 50° 59' and 54° 9', and then made
to revolve round O C as an axis, the first will intersect all the drops,
which, after two refractions and two reflexions of the red rays, will trans-
mit them in parallel lines to the eye ; and the second will determine the
analogous limit for the extreme violet rays. Between these two arcs
there will be others of all the intermediate colours of the prism, and they
will form a second coloured band, having a width of 54° 9' - 50° 59', or
3° 10'. This band will have its colours in an order the inverse of the
first, that is to say, the red will be inside, and the violet outside ; and the
distance between the two red arcs will be 8° 57'.'
In this account it is assumed that no sensible effect is pro-
duced on the eye of the spectator, after one or two internal
reflexions, except by those drops which are included within
the angles subtended by the coloured bands ; although it is
said that the whole expanse of the shower will exhibit a degree
of whiteness, in consequence of the reflexion of the sun's
rays from the anterior surfaces of the drops. These two
statements are, to a certain extent, I think, irreconcilable ;
for if the rays reflected from the internal surfaces would be
rendered insensible by their divergence, so also, I conceive,
would those reflected from the external surfaces. The disper-
sion of the former will not account for the supposed difier-
YOL, I. FEB. 1831, U
286 Mr. Ainger on the
ence, because each drop in the shower (with an exception to
be presently noticed) would transmit rays of every coloured
light, producing by superposition with themselves, and with
the rays from other drops, the sensation of white light, differ-
ing only in brilliancy from that reflected at the outer surfaces.
Mere divergence will not, I think, affect, to the extent sup-
posed, the apparent quantity of light derived from numerous
points at a great distance. It is true that a parallel pencil
would appear very bright at a distance, which would render a
divergent pencil, of equal magnitude, quite insensible. But,
in the case under consideration, it is not a single pencil of
parallel rays which is compared with another of divergent
rays ; the eye views a luminous space, part of which is so
distant, that a thousand drops might be contained in a line
having an inappreciable angular value. If the light from
each of these thousand drops proceeded in parallel lines, the
eye, although it would receive all the light transmitted by
some one drop, would lose all that was reflected by the others.
If, on the contrary, the light diverged from the drops, the eye
would receive only a very small portion of the light from the
one drop, but it would now receive an equal portion of the
light reflected from each of the remaining nine hundred and
ninety-nine drops ; the whole of which proceeding from a
space of no sensible magnitude, would produce a general
impression of illumination, notwithstanding that the light from
any single drop might have been invisible. An instance of the
effect produced by numerous simultaneous impressions, each
individually imperceptible, is furnished by a room in which
silkworms are feeding. A hundred of these animals emit no
sound that the ear can detect ; but the noise of a very large
number in the act of eating has considerable intensity. In
a large and crowded theatre no individual is heard to open
a play-bill, or turn the leaf of a book ; but if any circumstance
occasions a large portion of the audience to do either of these
nearly at the same instant, a noise is produced like the rushing
of a torrent. The correct statement, therefore, I think, would
be, that in addition to the reflexion from the anterior surfaces,
which is common to all the drops in the shower, every drop,
with the [exception before alluded to, is rendered visible by
Phenomena of the Rainbow. 287
li^lit twice refracted and once or twice reflected. The drops
which are not thus made sensible, are those contained in the
space subtending the angle between the red edges of the pri-
mary and secondary bows, which space is therefore compara-
tively dark, and constitutes the hitherto unexplained part of the
phenomena. The rainbow, it will have been observed in the
account of M. Biot, and I believe in all others, is described
as an insulated coloured band, rendered visible by the paral-
lelism of the rays, which emerge under a particular angle of
incidence, without any allusion to the illuminated space, of
which it is the coloured edge ; the colour being nearly analo-
gous to the coloured edges given to luminous objects when
viewed through lenses or prisms. The parallelism of the rays
at the maximum angle of deviation adds greatly to the bril-
liancy of the bow, as compared with the other parts of the
illuminated space, and contributes materially to its distinct-
ness, but is not, I think, properly called the cause of the bow.
The brilliancy not only of the bow, but also of the illuminated
space to some distance within it, is further increased by the
circumstance, that the drops in this situation return two sets
of rays to the eye, arising from light incident on both sides of
the angle, producing the maximum deviation.
The only parts of the theory of the rainbow, which appear
to be generally understood, are the circumstances which deter-
mine the limits and arrangement of the coloured bands, and
the various angles at which the several colours arrive at their
maxima or minima * of deviation. It is not, I think, commonly
imagined that the circular streak of red is merely part of a cir-
cular red space, the interior of which is rendered undistinguish-
able by the superposition of other colours. That this is the
case may be made evident by observing the progress of the
rays through a sphere or cylinder of water, placed at various
angles, with a luminous body, and the eye. If it be desired to
* Hitherto nothing has been said about a minimum of deviation ; but it will
presently be seen that the primary bow is formed by those rays which suffer a
maximum of deviation as compared with its illuminated space, while the secondary
bow is fonned by those rays which suffer a minimum deviation as compared with
iis illuminated space. Tins distinction must be borne in mind, because the rays
which, in the secondary bow, are. by comparison with the rest of the illuminated
space, said to be suH'eiing a 'minimum of deviation, do, in fact, deviate more than
those which, iu the primary bow, are said to be suffering a maximum.
U 2
288 Mr. Ainger on the
make this experiment without the intervention of glass, as it
is not easy to obtain either a sphere or cylinder of water un-
supported by a containing vessel, an equivalent form may be
procured by placing a drop between two small surfaces, as in
Fig. 5., near the middle of which the tangents of the opposite
Fig. 5.
surfaces will be parallel, which is, of course, all that is required.
I used the ends of two black lead pencils for this purpose ; but,
finding that a thin glass bulb did not sensibly affect the
results, I made the observations with that as being more con-
venient and manageable. In this way it will be seen, that,
although the rays transmitted near the maximum and minimum
angles of deviation are more brilliant than the others, yet the
difference is one only of degree, and is not sufficient to render
it probable that the latter are made invisible by mere diverg-
ence. The ray, after one internal reflexion, becomes dis-
tinctly visible as soon as it ceases to be confounded with the
ray obtained by reflexion from the first surface, as in Fig. 6. ;
Fig. 6.
and it continues to increase in brightness, but without sensible
colour, till the bulb arrives at the maximum angle of devia-
tion, for the violet rays of the primary bow, as in Fig. 7. ;
after which the light becomes more feeble and coloured, till it
vanishes altogether in a faint red. The same sort of progres-
sion is observed by commencing with a position of the bulb
directly between the eye and the light, in which there will be a
Phenomena of the Rainbow.
289
transmission of rays after two refractions and two reflexions,
though they will be rendered insensible by the superior
Fig. 7.
quantity of light immediately refracted. But so soon as the
angle is altered to avoid this, an image of the luminous body is
perceived, which arrives by the course shown in Fig, 8. The
Fig. 8.
deviation goes on diminishing * till the bulb approaches an
angle equal to that formed by the blue edge of a secondary bow ;
the light then changes to the various colours of the spectrum,
and escapes as before in a faint red, Fig. 9.
I have said, that in the preceding observations the image of
the luminous body was uncoloured, except when the bulb occu-
pied angular positions similar to those of the coloured parts of
the primary or secondary bows. It is, nevertheless, certain
that in all the other positions the light must have been more or
* The expression is liable to be misunderstood. The deviation is said to be
nothing when the ray returns exactly upon its own path ; consequently the devia-
tion is a maximum, or 180°, when it preserves its direction perfectly unchanged.
290
Mr. Ainger on the
less dispersed, and therefore that the images are rendered
colourless by the superposition of various coloured spectra
Fig. 9.
formed by the same drop, but so nearly coincident as to leave
exposed no sensible colour. The course of the rays must have
been something like that shown in Fig. 10., where the faint
whole lines may represent red, the broken lines yellow, and the
dotted lines blue rays, decomposed from the incident light which
is represented by stronger whole lines, s s s. Each drop in the
Fig. 10.
luminous space would return spectra of these three colours,
although they would be decomposed from different rays of
white light, arriving at the drop under different angles of inci-
dence. Their spectra would not perfectly coincide; but, if their
Phenomena of the Rainbow. 291
failure to do this be not perceptible in a bulb one inch in dia-
meter and near to the eye, it is not surprising that the light
from the rain-drops should appear colourless. The light at
length becomes coloured, partly in consequence of the coloured
rays arriving successively at the position of parallel emergence
and greatest brilliancy, as stated by M. Biot, and partly in
consequence of the drops failing successively to send to the
eye certain of the colours, the blue failing first, and the red
last.
From these observations it appears to me, that the pheno-
mena of this beautiful apparition are no where detailed as per-
fectly and comprehensively as they might be ; and I have
endeavoured, in the diagram, Plate 4., to convey a clearer
and more popular notion of them than is usually to be found.
Here the irregular figure A B C D represents a section of
a shower of rain, taken in any plane passing through the
eye of the spectator and the sun ; the former being at E, the
latter infinitely distant on the line E C. Under these circum-
stances, coloured rays, formed by two refractions and one
internal reflexion, will reach the spectator from every drop in
the cone whose section is E F G ; but the colours will be
nearly neutralized by superposition everywhere, except at and
near the surface of the cone, where they will give the impres-
sion of the primary bow ; the cone of red rays being larger
than that of the orange rays, this larger than the cone of
yellow, this again larger than that of green, and so on.
Coloured rays, formed by two internal reflexions and two
refractions, will reach the spectator from every part of the
shower, except the cone E H I, the colour being, as before,
neutralized by superposition in every part, except at and near
the extreme edges of the illuminated space, where each colour
will successively overlap the last, in the same order as before,
producing the secondary bow.
The space between the two cones, E F G and E H I, returns
no light after one or two internal reflexions, and is therefore
comparatively dark, though the difference is by no means so
great as, for the sake of distinctness, it has been made in the
engraving.
In confirmation of the view here taken of the causes which
292 Mr. Ainger on the
produce the comparative darkness in question, it may be noticed
that the violet edge of the bow is extremely ill defined as con-
trasted with the red edge. In some cases, the colour can with
difficulty be traced beyond an indistinct green, the remainder
seeming to be merely the commencement of the blue colour of
the atmosphere. According to the descriptions usually given, this
difference would not exist ; the parallel emergence of the violet
rays ought to produce a very distinct line of violet light,
because the red and yellow rays are in that situation subject
to considerable divergence. But the fact is, that notwithstand-
ing their divergence, they are far from imperceptible ; and,
mixing with the parallel violet rays, they confound and almost
obliterate them, or rather unite with them to produce the
impression of common compound light.
The superior brilliancy of the primary bow is not, I think,
quite accurately accounted for when it is ascribed to the cir-
cumstance of its rays having suffered but one reflexion ; for
the double reflexions are made at angles so favourable, as
nearly to counterbalance this difference. I apprehend that the
faintness in the latter case is owing to the following causes : —
1. That the rays which suffer the maximum deviation in the
primary bow arrive at the surface under a much smaller angle
of incidence than those which suffer the minimum deviation
in the secondary bow ; the latter, therefore, are more copiously
reflected from the first surface, and enter the drop in much
smaller quantities.
2. That the angle at which the ray is afterwards refracted
from the inner surface to the air, is, in the secondary bow,
similarly favourable to reflexion, and unfavourable to refrac-
tion, so that only a small portion of the already reduced quan-
tity of admitted light is refracted.
3. That the extent of the dispersion is increased by the
second reflexion, as is shewn by the greater width of the
secondary bow.
The last circumstance may, perhaps, be considered as
included in the expression that the faintness is owing to the
second reflexion, though it is not very obvious that such is
the meaning.
Phenomena of the Rainbow. 203
These observations having been suggested by your remark,
I I ><.'<;• leave to address them to you, and to place them at your
disposal.
Remaining, my dear Sir, yours very respectfully,
ALFRED AINGER,
To M. Faraday, Esq.
&c, &c. &c.
ON THE MODE OF ASCERTAINING THE COMMERCIAL
VALUE OF ORES OF MANGANESE.
BY EDWARD TURNER, M.D., F.R.S. L. andE., SEC. G.S.
Professor of Chemistry in the University of London.
fPHE analysis of the ores of manganese, when pure, is ex-
• ceedingly simple. The operator need only, by well known
methods, determine the water which the ore contains, and the
oxygen which it loses in being converted into the red oxide.
Its degree of oxidation, on which the commercial value of ores
of manganese so essentially depends, may then be readily
inferred.
But when impurities prevail, as they almost always do,
more or less, in commercial manganese, the analytic process
is complex and troublesome ; and the presence of iron, which
is rarely absent, renders an exact result by the ordinary modes
of analysis almost impracticable. For, as I have elsewhere
stated*, when peroxide of iron is strongly heated in mixture
with peroxide or deutoxide of manganese, oxygen is given out
by the former as well as by the latter ; and, accordingly, the
oxygen lost by heat ceases to indicate the nature of the man-
ganese. A moderately correct allowance for the quantity of
oxygen emitted by the iron under these circumstances would
be difficult, even after ascertaining in the moist way the quan-
tity of iron contained in the ore ; since the constitution of the
resulting oxide of iron, as well as its uniformity, is probably
variable, and, at all events, is undetermined. The chemist
would, therefore, have to ascertain separately each constituent
* Brewster's Journal of Science, N.S. ii, 213.
294 Dr. Turner on the Mode of ascertaining
of the ore, and consider the loss as oxygen belonging to the
manganese, — a method not to be trusted in a complicated
analysis, and which would be wholly inapplicable if the iron,
as contained in the ore, should happen not to be uniformly
oxidized.
I was led to reflect on these difficulties in consequence of
being requested, some months ago, to examine a considerable
number of different ores of manganese, the object being solely
to ascertain the relative quantities of chlorine which an equal
weight of each ore was capable of supplying ; and as the
method to which I had recourse gives such information with
rapidity and precision, I have drawn up a short description of
the process ; not from any novelty being attached to it, but in
the belief that it may be useful to persons engaged in a similar
inquiry.
The method, in principle, consists in dissolving a given
weight of the ore in muriatic acid, condensing the chlorine in
water, and, by some uniform measure, estimating the quantity
of chlorine relatively to an equal weight of pure peroxide of
manganese, selected as a standard of comparison. The sub-
stance first used with this intention was a solution of indigo ;
but a weak solution of green vitriol, employed by Mr. Dalton
for ascertaining the strength of bleaching powder, was found
to be more precise in its indications.
The method of manipulating is as follows : — About ten grains
of the ore in fine powder is introduced into a flask capable of
containing about an ounce of water, and into its neck is fitted
by grinding a bent tube about two inches long, which conducts
the chlorine from the flask into a tube about sixteen inches in
length, and five-eighths of an inch wide, full of water, and
inverted in a small evaporating capsule, employed as a pneu-
matic trough. The apparatus being adjusted, the flask is half
filled with concentrated muriatic acid, the conducting tube
instantly inserted, and heat applied by means of a spirit-lamp.
The air of the flask, together with the chlorine, is then collected,
the greater part of the latter, if the gas is not very rapidly dis-
engaged, being absorbed in its passage ; and, consequently, the
receiving tube, at the close of the process, will be about half
full of gas. When the ore is completely dissolved, the last
the value of Ores of Manganese. 295
traces of the chlorine are expelled from the flask by muriatic
acid gas. In order that the chlorine thus collected may be
entirely absorbed, the aperture is closed by a ground stopper,
or, still more conveniently, with the finger, and the gas is well
agitated until the chlorine is wholly absorbed. As the solution
in the inverted tube may become too saturated to dissolve all
the chlorine, it is convenient to fill a pipette with pure water,
and, with the aid of the month, force a current to ascend into
the tube, and thereby cause the heavier solution to flow out
into the capsule.
The absorption being complete, the solution of chlorine is
introduced into a six or eight ounce stoppered bottle, and a
dilute solution of green vitriol, made, for example, with a
hundred grains of the crystallized salt and a pint of water, is
added in successive small quantities until the odour of chlorine
just ceases to be perceptible. The quantity of liquid required
for the purpose may be conveniently measured in a tube about
sixteen inches long, and three-quarters of an inch in diameter,
divided into two hundred parts of equal capacity, and supplied
with a lip, so that a liquid may be poured from it, without being
spilled. In conducting this part of the process, the operator
will perceive two odours: — at first, the characteristic odour of
chlorine, accompanied with the peculiar irritation of that gas ; —
and subsequently an agreeable, somewhat aromatic odour,
unattended with the slightest irritation. The object is, to add
exactly so much solution of iron as suffices to destroy the
former of these odours, without attempting to remove the
latter ; a point which, with a little practice, may be readily
attained. The whole of the iron is thus brought into the state
of peroxide.
The first trial is generally accompanied with some loss of
chlorine, and should only be used as a guide to a second and
more precise experiment. Accordingly, a weighed portion of
the same ore is dissolved, and the chlorine collected as before,
except that the solution of green vitriol, in quantity rather less
than sufficient, is at once introduced into the inverted tube and
capsule. A more ready and perfect absorption of the chlorine
is thus effected, and the subsequent addition of a small quan-
tity of sulphate of iron suffices for completing the process.
296 Dr. Turner on the Ores of Manganese.
The principal sources of error in this method are the two
following : — loss of chlorine, by smelling repeatedly, and expo-
sure to the air when the gas is absorbed by pure water ; and
oxidation by the air when the absorption is made directly by
means of the solution of iron. The small flask and inverted
tube are apt to retain the odour of chorine, and should there-
fore be rinsed out with the absorbing liquid. It should be
remembered, also, that a given quantity of chlorine will emit a
more or less distinct odour, according as it is less or more
diluted. But by operating always in the same manner, and
employing such weights of different ores, that equal quantities
of the solution may contain nearly equal quantities of chlorine,
it is easy to be independent of these errors of manipulation, by
causing them to affect each experiment to the same degree.
It will accordingly be found, with a little practice, that results
of surprising uniformity may be thus obtained ; and even the
constitution of pure oxides of manganese may be ascertained
by this method, almost with the same accuracy as by directly
determining the quantity of oxygen.
PHENOMENA OBSERVED AT THE LAST ERUPTION OF
MOUNT VESUVIUS IN 1828.
BY DR. E, DONATI.
A FTER the tremendous eruption of 1822, Vesuvius re-
"^^ mained silent and apparently calm, until the 14th of
March, 1828. At this time the volcano presented to the
eye of the curious a truncated cone, steep and difficult of
ascent, two hundred toises * in height : and a vast crater,
half a mile in diameter, but of which the periphery, owing to
the many irregularities of its outline, was nearly three miles in
extent. The depth of the interior, which resembled an in-
* The celebrated Humboldt, on the 25th of November, 1822, took the baro-
metrical measurement of the greatest cone, and found that the point Del Palo,
was at an elevation of 223 . 6 toises above the plane of the cone, where travellers
usually leave their horses to proceed on foot. This height is now diminished by
fifteen toises j the materials which formed the summit having fallen into the
interior of the crater.
Dr. Donati on the Eruption of Mount Vesuvius. 297
verted cone, of a somewhat elliptical form, was about one
hundred and sixty-six toises ; the surface of the upper part
consisting of semivitrified lava, containing much amphigene
and pyroxene; and from the south-west to the north, divided
here and there, like basalt, by vertical fissures, to the depth of
two toises. Other varieties of lava which occur here present
occasionally capillary amphibole, of a reddish brown colour,
produced by the eruption of 1822.
Many small volcanic mouths (fummaioli) in the interior of
the crater, exhaling aqueous vapour, together with sulphureous
and muriatic gas, had generated sublimations of muriate of
soda and of copper. These apertures, which, during the
eruption of 1822., presented a scene completely volcanic,
appeared to be re-animated in November, 1824, by an in-
crease of temperature, and emitting dry vapours, produced the
corneous muriate of lead (cotunnia) already described in the
catalogue of Vesuvian productions.
Active smoking apertures and broad clefts began to be
visible in April, 1826, in the interior of the crater facing the
north ; from these arose aqueous vapour united with sul-
phureous gas, which attacked the lavas, decomposed them,
and generated considerable quantities of sulphate of lime in va-
rious forms, acicular, radiated, dendritic, and a bouquet. Lower
down, but not far from these apertures, were others which
afforded sublimations of a blue colour, semi-crystallized, which,
upon examination, proved to be the bisulphuret of copper.
The last-mentioned apertures no longer exist, having been
precipitated into the bottom of the crater, together with part of
the sides, to which they were attached. At the bottom of the
crater was a large funnel-shaped opening about three toises in
depth ; and in June, 1826, appeared two new and active volcanic
mouths to the east and north of it. I descended boldly ; but
the excessive heat and acidulous vapours impeded respiration ;
I could not approach near to the eastern one. The northern
one afforded sublimations of trisulphuret of iron, brown and
confusedly crystallized in small rhombs ; and abundance of
sulphate and persulphate of iron and manganese, and also
muriatic salts. Every step and stroke, however slight, on the
298 Dr. Donati on the
lower part of the funnel, resounded in a manner which showed
that the ground was hollow ; the lava forming only a super-
ficial volcanic crust. Signer Monticelli, who, together with
Professors Corelli, Petagno and Costa *, was a spectator of
my adventurous exploit, gave an account of it to the Royal
Academy of Sciences. I was able to measure, by approxima-
tion, the depth of the interior of the crater, which was the same
as I have already indicated (one hundred and sixty-six toises).
A large quantity of materials rolling from the inside of the crater
had filled the funnel at the bottom— the volcanic aperture to the
north Was exhausted, and that to the east had so far diminished
in activity, that scarcely any vapour proceeded from it, But
towards the end of 1827, others broke out on the southern
side of the interior of the crater, which produced much per-
oxide of iron, in brilliant laminae of a fine deep red colour ;
muriate of copper resembling lichen, and large stalactites of
muriate of soda. The sides of the crater were much split
near this part ; and after a few months these, also, were pre-
cipitated into the bottom of the abyss.
On the 14th of March, 1828, suddenly, and without any
previous notice, either by the disappearance of water or
trembling of the earth, at about two o'clock in the after-
noon, the above mentioned aperture near the bottom of
the crater on the eastern side, although apparently exhausted,
gave a tremendous shock, which not only shook the cone
of the volcano, but was felt as far as the Hermitage — the
forerunner of a new eruption | ! The air now resounded
with thunder and hollow bellowings ; and from time to time
shocks succeeded each other with increasing violence. All
kinds of loose and detached substances which formed the
covering of the aperture, were projected into the air; and
* Signer Costa found at the same time, near the mouth which produced the
bisulphuret of copper, some insects of the family Cloteropti, which existed in a
temperature of 60° Reaumur, and in an atmosphere loaded with scorching dust.
-j- On the 14th of March, occupied in mineralogical researches, I traversed the
Fossa Grande, after having visited the Atrio del Cavallo, where a stratum of
vitreous trachyte occurs, in which small laminae of brown mica are disseminated.
This rock is exactly similar to that called by the Italians Occhi di Pernici ; and
to another found in the Isle of Paneira. Scarcely had I felt the first shock,
when, expecting an eruption, I mounted the very summit of the cone ; and was a
spectator of the first changes which took place.
Eruption of Mount Vesuvius in 1828. 299
falling again into the middle of the crater, in less than half an
hour formed a small cone, which vomited globes of bluish
white smoke and sparks and flashes of fire. The shocks, which
resembled the discharge of immense cannons, were now re-
peated every minute, the last always exceeding the former
ones in violence. The entire surface of the bottom of the
crater, and the sides adjacent, exhibited constantly a heaving
motion ; and at the moment when the fused and red-hot
materials were thrown into the air, the bottom as well as part
of the interior sides which were already moved from their
position, sunk and rose again. This phenomenon was re-
peated every time that the subterranean detonations were felt,
and the heaving continued until the moment of the expulsion
of the lava, which scarcely reached the edge of the little cone.
This, as if on the point of disgorging itself entirely, projected
impetuously into the air a stream of materials accompanied by
dense white and red smoke.
It seemed as if the axis of the volcanic funnel were in the
centre of the new cone ; for all the substances were ejected
perpendicularly from it, dispersed through the air, and fell
again in various forms.
As the evening advanced, these phenomena augmented.
The wind blew from the south, and spires of smoke resembling
pine-trees, and scarcely rising through the air, inclined towards
the most elevated part of the cone,, called il Palo. The sky
was serene, and experienced no interruption of its tranquil-
lity, although between the eruptions were heard loud ex-
plosions and a bellowing sound, whilst electric sparks rose in
the air.
On the 15th, the summit of the cone appeared covered with
globes of dense smoke, rising one above the other ; the bottom
of the interior was entirely covered with scoria ejected from
the funnel : the shocks were not so frequent, and the rumbling
noises had considerably decreased. At noon, however, all
their former violence returned, and they appeared even louder
than before; their intensity increased from three till seven
o'clock in the evening ; so that the accumulation of melted
substances had, by this time, elevated the bottom of the crater.
In this state, without any sensible variation in the pheno-
300 Dr. Donati on the
men a which it exhibited, the volcano remained until the night
of the 20th of March. But on the morning of the 21st, the
scene was entirely changed, and became very striking. Two
additional volcanic apertures opened ; one to the north, about
twenty feet in diameter; the other very small, and situated be-
tween this and the one which gave the first signal of volcanic
action. Loud explosions and violent shocks reverberated, not
only through the interior of Vesuvius, but were felt as far as the
city of Naples. The eastern mouth incessantly ejected matter
in a state of fusion, peperidicularly to the height of forty or
fifty feet in the air ; and when a current of fire was thrown out
by one it was immediately succeeded by a jet from the other.
A constant motion of ascent and descent was felt, and volumes
of smoke were disengaged, of various colours — white, reddish,
blue and black.
The northern mouth, perfectly circular in form, gave from
ten to fifteen violent shocks every minute ; and threw into the
air melted substances, sometimes with brownish white, and
sometimes with azure-blue smoke : the liquid lava now flowed
from the margin in various directions, and spreading itself in
the air, formed a hemisphere of transparent glass, which,
either from the impossibility of extending itself, or from the
pressure of the air, or because the internal vapours forced
themselves a passage through it, broke in many directions, and
fell again into the fiery fountain whence it arose.
The little mouth, every one or two minutes, gave a shock
considerably stronger than those of the larger one. Opening
itself into an ample basin, it ejected the very materials of which
it was formed, and those which were continually falling on it
from the lateral apertures. The scoriaceous lava, brown on
the surface, but liquid within, beat against the interior sides of
the cone, rising by degrees with a waving motion. The phe-
nomena did not preserve the same character as on the pre-
ceding days, but increased with gigantic progress ; at every
shock the whole cone trembled, and an undulatory motion
extended as far as to Resina and other parts of the surrounding
country ; the smoke continued to rise in large globes at the
summit of the crater.
At two o'clock I went round the perimeter of the cone, to
Eruption of Mount Vesuvius in 1828. 301
observe what part would be most likely to give way under the
impetus of the shocks. To the south I found many wide
openings and deep fissures ; but the suffocating acid vapours
and the rain of scoriae, which was then falling, obliged me
immediately to quit my position, which was, in fact, be-
coming extremely dangerous. I met with other fissures at
II Palo, where there appeared no present danger.
The inhabitants of Naples, on the 21st, began to perceive
the spires of smoke, and in the evening the jets of fire, and
the country around to fear the effects of such appearances.
There was much electricity in the air ; the electric fire was in
constant motion, and appeared to incline to the negative pole ;
the barometer and thermometer indicated no sensible variation ;
the apertures at the base (la pedamentina) and along the cone
exhaled but little vapour, and remained at the temperature of
70° Reaum.*
These phenomena remained in a state of continual pa-
roxysm till the evening of the 22d ; and far from abating in
violence, they increased so much, that two new apertures
broke out, which, together with those already existing, deto-
nated loudly, and ejected the melted lava to the distance of two
thousand feet. Although the force acted obliquely, the melted
matter reached a height exceeding that of the crater and of
Monte Somma; and fell at various times in the night at Ottajano,
in large and small pieces of perfect scoriaceous lava.
The morning of the 23d, the bottom of the crater was
raised one-fourth, and seventeen volcanic mouths were in full
action, exploding, shaking the earth, and throwing out melted
matter in various directions, obliquely and even horizontally ;
vomiting also globes of smoke of various colours, which from
time to time filled the vast area of the crater, and then, rising
like huge machines into the air, assumed the appearance of
magnificent columns. A mouth, which opened on the southern
part from midnight till two o'clock the following day (24th),
ejected fused substances, and the scoria of the lava which was
within it, obliquely to the point del Palo, and they fell on the
external part of the cone in large and small masses. All the
spectators now abandoned the place ; but in a few hours after
this crisis, the activity of the volcano began to diminish and
VOL. I. FEB. 1331. X
302 Dr. Donati on the
eight apertures closed. In the evening, the three first only,
and with detonations less loud than before, threw into the air
jets of sparks. The first, to the east, was in constant action ;
that to the north, and the one between them, exploded from
time to time like the first ; and all the other smaller ones,
sometimes exploding, sometimes throwing up showers and
columns of sparks, presented the appearance of most brilliant
fireworks.
The lava which filled the bottom of the crater was in some
parts semicircularly divided by concentric strata of fire, which,
in the northern and south-eastern parts, appeared as if ani-
mated by a subterraneous current of air ; and from time to
time, in some places, globular masses of the fused matter rose
on the surface and rolled towards the centre. The barometers
lowered ; and the rain which fell during the night brought
some degree of calm.
On the night of the 25th the northern aperture only re-
mained in action. It ejected, with a loud bellowing, (at inter-
vals of half an hour, and sometimes an hour,) smoke and
flames : the latter were visible even from Naples ; and the
smoke rose in the form of pine trees, inclining to the north.
The great aperture to the east, and the smaller ones, were in a
state of tranquillity. Rain fell again in the night ; and on the
morning of the 26th with hail. Vesuvius and the Monti di
Somma were covered with the latter ; but during the day it
disappeared. In the evening, the explosions of the northern
mouth recommenced, so that every two minutes this aperture
vomited globes of dense black smoke ; and large quantities of
very fine sand, of a dark brown colour, rose in the air and fell
towards the north-west, on the summit of the cone and within
the crater, throughout the greater part of the night. All the
other mouths were entirely spent. The same aperture, during
the whole of the 27th, becoming gradually exhausted, gave
very slight shocks, resembling in sound the discharge of a
musket ; and in the evening, reviving for a few minutes, gave
five or six as loud as the report of a cannon, discharging
at the same time flames and smoke, and during the night,
ceased.
On the morning of the 28th, Vesuvius remained in a state
Eruption of Mount Fesuvius in 1828. 303
of perfect calm ; but the examination of the crater was still
interesting. The whole of the interior appeared as if lined
with black velvet, in consequence of the great quantity of sand
which fell on the 26th. The bottom of it, by the frequent
rising of the substance which formed it, and by a mass of
scoriaceous lava which accumulated on its surface, was raised
above its former level about forty toises, or perhaps still more,
adjoining the sides. It appeared like the scum which, lines a
vessel when filled with a liquid in a state of fermentation.
On the north-east the lava had already formed an oblique
eminence, supported against the interior surface of the crater,
where there still remained vertical fissures, animated with
living fire, and exhaling much vaporous smoke. This eruption
was exceedingly beautiful and interesting ; for every volcanic
or igneous phenomenon which took place was observable,
without danger, within the vast area of the existing crater.
The shortness of the volcanic crisis can be attributed only to
two causes; firstly, because the volcanic funnel was very
superficial, and very little resistance was opposed to the
igneous power, which, being exhausted, could scarcely furnish
from itself more combustible materials, because deficient in
them ; secondly, because subterraneous currents of air pre-
vented the fire from receiving the inflammable materials from,
strata beneath. This opinion may be thought a bold suppo-
sition ; but in observing the mode of action of the volcanic
mouths, the same appearance was visible as when a fire is
blown with a pair of bellows. This idea has occurred to me
from what I have many times noticed, and which may be
verified at the present time, that in some fissures in the western
part, the air enters with a loud whistling sound, but perfectly
kalophonious. During the short time of the eruption, the
water did not decrease in any of the wells in the neighbour-
hood of Vesuvius.
The pumiceous scoriae, which fell on the 21st on the
southern part of the summit of the cone, were of a greenish
colour, and filamentous ; some filaments not thicker than the
finest hair, and others an inch in diameter. The result of the
mechanical analysis, — a method adopted by Professor Cordier,
—showed them to consist of an intimate mixture of pyroxene
X2
304 Dr. Donati on the
and vitreous amphigene, imbedded in a vitreous paste. The
heavy scoriaceous lava, which fell in Ottajano, and on the
point del Palo, from one to eight inches in diameter, consist
also of pyroxene and vitreous amphigene. The great mass of
lava is very tenacious, slaggy, and brown ; the scoriaceous
part rough and uneven, with crystallized pyroxene (which is
usually the bisunitain variety), covered with brown fused coat«
ing, and internally of a deep green colour. These scoriae con-
tain but little lime, and a large proportion of iron. The brown
sand, which fell on the night of the 26th, consisted of micro-
scopic particles of scoriae, pumice, a mixture of amphigene
and vitreous pyroxene, laminae of mica, and a large quantity
of magnetic iron in a state of the finest powder, a large pro-
portion of permuriate of iron, some muriate of soda, and a
small portion of sulphate of soda. I could not at this time
descend to the bottom of the crater to observe the sublima-
tions in the funnel, because, although extinguished, there was
yet danger.
APPENDIX.
Vesuvius, after the 28th of March, presented no visible
alteration till the 3d of July, except in the enlargement and
extinction of the vertical fissures on the north-east, which had
glowed so vividly. An undulatory trembling of the earth was
sensibly felt at Marsala in Sicily, about the 15th of June ; and
towards the end of the month an explosion of gas took place
in the isle of Ischia, which considerably damaged the sur-
rounding land. It was observed very distinctly at Castella-
mare, and along the coast as far as Plantelleria ; and the baro-
meters and thermometers rose and fell in a very extraordinary
manner.
On the abovementioned day (July 3), at three in the after-
noon, one of the volcanic mouths near the centre of the crater
re-opened, and, dislodging all the extraneous materials that
lay upon and around it, threw into the air, with rumbling and
bellowing sounds, brilliant fire, with dense smoke of various
colours, and very shortly spread itself into a large basin ; the
fused substances which it furnished, falling again upon itself,
Eruption of Mount Vesuvius in 1828, 305
began in a little time to form a cone, which, on the 4th, had
risen to the height of nearly one hundred feet, truncated hori-
zontally at the summit, where it appeared about eighteen feet
in diameter. This cone became the base of two semicircular,
ignivomous apertures, one sloping towards the north, the other
vertical. They occupied a considerable part of the trunca-
ture, leaving, however, a large part unaltered in appearance.
The explosions were renewed about every three minutes ; the two
mouths alternating with each other. Part of the scoriae, which
fell, rolled down the declivity of the new cone, and part rested
on the summit ; so that it increased both in height and dia-
meter. Flames, with bluish smoke, continually issued from
these mouths, with a whirling motion, and, while rising in the
air, preserved (as before) the form of pine trees. All the
sides of the great cone appeared to have an undulatory motion.
This I verified by placing a pitcher full of water on the highest
point of the great cone. The water, at the moment when the
subterranean detonations were felt, manifested an undulating
motion, and fell from the sides of the pitcher. I repeated the
experiment several times, and the same undulation constantly
took place ; so that, although the present eruption was nothing
in comparison with so many others which had taken place, it
appeared conclusive that it was sufficient to impart an undula-
tory motion to the whole of the cone.
The rain which fell at three o'clock on the night of the 5th
of July seemed to cause a cessation of the igneous explosions ;
but instead of these, cinders were ejected, of a grey or brown
colour, which fell on nearly all the hills in the neighbourhood
of Vesuvius, and on the plains and gardens of the Torre dell1
Annunciata. The husbandmen were not sorry to find their
lands covered with this heated sand, for experience had taught
them its utility in the culture of cotton and rice.
On that morning Vesuvius appeared most interesting, and
particularly at the rising of the sun, which was immediately
preceded by a rainbow — a magnificent spectacle, and which I
have never before known to have been observed.
To attempt an explanation of this very short eruption would
be to immerse oneself in a sea of conjectures, without deriving
306 Eruption of Mount Vesuvius in 1828.
any profit from them. I have thought it more useful to give
a vertical section of the great cone, and of the small one pro-
duced in the centre of it.
The section of the cone 'of Mount Vesuvius seen from the interior, looking to-
ward the W.N.W. The point at which visiters generally place themselves to see
the interior of the crater is at S.S.E.
1. — Bottom of the crater before the eruption.
2. — Scoriae and lava thrown up during the eruption.
- 3 Cone formed during the lesser eruption at the beginning of July.
4. — Amphigenous pyroxenic vitrified lava, of the eruption of 1822; in some
parts this lava, when it has beneath it smoke vents which exhale fumes, divides
itself into coarse prisms.
5. — Stratum of Rapilli (i. e, white pumice) and labbie (dust).
6. — 'Stratum of pumice, and small fragments of scoriae tinged with oxide of iron.
7. — Current of lava Leveitica (greenstone).
8. — Current of lava mixed with pyroxene. Lava of the same kind is found in
the veins of the great dike (Fossa Grande}.
9.— Current of lava mixed with pyroxene. It contains (in the geodes) very
small crystals of pseudo-nesseline, and a small quantity of breislakite. The frag-
ments of this lava crumbles into large prisms, like that at Scala near Portici,
which is termed basaltica da Brocchi.
10. — Stratum of rapilli and labbie, impregnated with the fumes which exhale
from the fummaioli smoke in that part, with efflorescence and sublimation of
sulphur, muriate of soda, and copper. The sublimation makes this spot appear
like a cultivated garden.
11. — Current of lava, divided into great prisms. This place is inaccessible.
12. — Rapilli and pozzolana, with globules of the Vesuvian dolomite of Thomson
and of lava. These same materials are found far from the external walls, as well
on one side as the other.
( 307 )
A MODE OF REGULATING THE SUPPLY OF WATER BE-
TWEEN INTERSECTING RIVULETS AND CANALS.
DEVISED BY THE LATE ROBERT ALMOND, ESQ.
of Nottingham.
[Communicated by MARSHALL HALL,M.D.,F.R.S.E,,&c.&c.]
rPHE Nottingham and Erewash canals diverge from the same
point, at Langley Mill, in the county of Derby, and are
terminated at the distance of a few miles from each other, by
the river Trent. In consequence of this relative situation, the
Nottingham, which was cut most recently, intersected some of
the rivulets which had previously fallen into the Erewash. To
compensate for this injury, an eminent mathematician devised
the following ingenious plan of delivering from a reservoir of
the Nottingham Canal, a given quantity of water per minute,
under every variation of the height of water in the reservoir.
The water is brought into a small cistern, of which A (Fig. 1.)
represents part of the end. b is an aperture, parallel with the
horizon, which would of itself deliver the stipulated quantity
when the water in the cistern is at its greatest height, a is a
vertical aperture, connected with the former, and is quite
closed by the shuttle B, when the cistern is full. Its sides are
of that peculiar curvature, that as the shuttle is raised by the
action of the buoy C, descending with the surface of the water
in the cistern, the additional part of the aperture disclosed
exactly compensates for the diminution of pressure. This plan,
however, though correct in theory, proved altogether abortive
in practice, on account of the excessive friction which is pro-
duced, partly by the motion of the shuttle in a groove, and
partly by the lateral pressure of that portion of the water which
is above the disclosed part of the orifice*.
A dispute afterwards arising respecting the Gilt Brook,
which the Erewash Company deemed valuable in the dry
summer months, and which had formerly been one of their
feeders, they demanded a regular supply of water, according
to the average quantity which the brook should be found to
deliver in the months of June, July, and August. This quan-
* The investigation of the curve proper for the sides of the aperture, is furnished
ty the inventor m the < Gents. Diary for 1799.'
308 A Mode of Regulating the Supply of Water
***
between intersecting Rivulets and Canals. 309
tity proved to be 11 .25 cubic feet per minute ; but a great diffi-
culty now arose respecting an impartial mode of supply, and
this difficulty appeared greater in consequence of the failure
of the former plan. At length the dispute was amicably
adjusted by the following method, which was invented and
carried into execution by Mr. Robert Almond, of Nottingham,
then one of the proprietors of the Nottingham Canal.
A (Fig. 2.) represents a pipe placed under the haling path
of the Nottingham Canal, having the end, which communi-
cates with the canal, turned downwards to prevent stones and
dirt from falling into it. Its other extremity is connected with
a large cast iron vessel B, in which the water necessarily rises
to the level of that in the canal. C is a copper syphon,
balanced in such a manner, partly by means of a hollow
copper sphere, through which it passes, and partly by two
weights passing over the wheels, as represented in the draw-
ing, that it rises and falls freely with the water in the canal.
By this contrivance, the discharging orifice of the syphon will
always be at equal depths below the surface of the water in the
canal, and must therefore constantly deliver equal quantities
in equal times. D is a stone cistern, into which the water
runs, after being discharged from the syphon, and which serves
as a gauge, open to the inspection of passengers. On its inte-
rior side, a plabe of copper is placed perpendicular to the plane
of the section, and which is made visible by the stone being cu t
down to its edge. The water always remains level with this
plate, whilst a discharge is taking place from the pipe P.
It must appear to every one versed in hydraulics, that,
owing to the friction of the water against the sides of the
syphon, its velocity must be retarded, and that the discharging
leg must be longer than the theory of emptying vessels would
lead us to suppose. This remark is verified by the case before
us. The internal diameter of the syphon is 2.45 inches, and
the lower orifice is 21.03 inches beneath the level of the canal;
but, according to the theory, which supposes that the velocity
at the orifice is that acquired by a body falling from rest
through a space equal to half the depth of fluid above it, the
depth of the lower orifice = qU&ntlty discharged per 1^ _
area of orifice")2 x 386
12.22, &c., each term being expressed in inches. It is
310 A Mode of Regulating the Supply of Water, fyc.
therefore advisable, in the construction of such an apparatus,
to make the difference of the legs of the syphon double that
which the theory requires, and then to reduce the longer to
its proper accuracy by absolute experiment.
The above equation is of more use in the construction of the
gauge cistern. The depth above the pipe being assumed
greater than is wished, the area of the pipe may be calculated,
and the stone be afterwards cut down to the level at which the
water is observed to remain.
When the apparatus is once regulated, the syphon and
weights should preserve an exact balance in every point of
ascent and descent ; as the accuracy of the discharge depends
in a great measure upon that circumstance. If strong catgut,
or any light cord, be used to connect the syphon with the
weights, the equilibrium may not be sensibly affected by the
motion of the syphon. In the present case light chains
are used ; and, as the wheels are about two feet in diameter,
half a revolution, or a variation of three feet in the level
of the canal will take the weight of six feet of chain from one
side of the axle, and add it to the other. To obviate this in-
convenience, one of the wheels has a piece of lead attached to
its side, which is narrower at its extremities than at its centre.
W (Fig. 3.) represents the wheel thus loaded, and in its situa-
tion when the syphon is at its lowest point.
It only remains to observe, that this simple apparatus, which
is so easily regulated by a little increase or diminution of the
weights, has now been at work for more than fourteen years,
without any alteration in its adjustment, and to the perfect
satisfaction of all parties. A very intense frost has once or
twice suspended its operation, but the succeeding thaw has
enabled it to resume its function of a constant arbitrator.
Nottingham, 1826. R. W. A.
Note. — A floating syphon, with wheels and balance weights,
is, we believe, fully described in the article ' Hydrodynamics/
in Brewster's Encyclopaedia ; but the date of the article is by
much posterior to the first erection of the instrument described
above, and which has the authority of twenty years constant
use. — Editor.
( 311 )
ON THE GEOMETRIC PROPERTIES OF THE MAGNETIC!
CURVE, WITH AN ACCOUNT OF AN INSTRUMENT
FOR ITS MECHANICAL DESCRIPTION.
T
BY P. M. ROGET, M.D,, SEC. R.S.
HE properties of the magnetic curve being interesting to
the geometrician, as well as important in their connexion
with the theory of magnetism, I am induced to offer the follow-
ing demonstrations of the two fundamental propositions re-
specting them, derived directly from the law of magnetic
forces, as being more simple than any of those given by Pro-
fessors Robison, Play fair, or Leslie. I have also added an
account of a method I have devised for the mechanical de-
scription of these curves.
The principal problem relating to the magnetic curves is to
find the direction, CT, Fig. 1. of the tangent to the curve
Fig. 1
which passes through any given point C, when the situations
N and S of the two poles are given. This direction indicates
the position which an infinitely small compass needle, placed
at C, and at liberty to turn freely round its centre, in a plane
passing through N and S, will assume by the action of the
magnet N S. This position must be such, that the rotatory
forces exerted on both poles of the needle by each pole of the
magnet shall exactly balance one another.
The forces themselves, according to the established law of
magnetic action, are inversely as the squares of the distances
312 Dr. Roget on the
of the acting poles ; which distances, in the case before us,
are the lines C N and C S. But that part of each force which
is effective in producing rotation, is, by the resolution of
forces, as the sine of the angle which the direction of the
force makes with the radius of rotation. Taking both these
circumstances into account, the rotatory forces exerted by the
two poles are to one another in a ratio compounded of the
sines of the angles N C T and S C T, and of the recipro-
cals of the squares of C N and C S. For the convenience of
notation, let these rotatory forces be denoted respectively by
the letters R and r.
Let C N = n
CS = s
The angle NCT = v
The angle S C T = a
The length of the magnet, or N S = m.
The portion of the produced axis S T intercepted between S
and the line C T = x
From the points N and S, let fall upon C T
the perpendiculars N P = p
and S Q = q.
The triangles N P T and S Q T being similar
p : q : : m + x : x
Also sin v = £— ; and sin a -=L JL :
n s
mi r> sin v sin a p q m + x x
inen, \\ i T i 1 '. '. '.— — ; -i—i i — . — i —
n* *a n3 s3 n3 s3
But in the present case R = r ; therefore m + x = —\
n3 s3
hence n3 — s3 : s3 : : m : x.
That is, C N3 - C S3 : C S3 : : N S : S T.
Hence, in order to determine geometrically the point T, in
the axis N S produced, and thereby the direction of the line
C T, which is the position of equilibrium for the infinitely
short needle C, and the tangent to the magnetic curve at that
point, we must take on that axis a distance S T such that it
Geometric Properties of the Magnetic Curve. 313
may be a fourth proportional to the difference of the cubes of
C N and C S, the cube of C S, and the line N S *.
The most remarkable property of the magnetic curve is,
that the difference of the cosines of the angles, which lines
drawn from any point in the curve to the two poles make with
the axis, taken on the same side, is a constant quantity.
In order to demonstrate this proposition, we must take
another point, C', in the curve, Fig. 3. exceedingly near to the
Fig. 3.
former point C ; and from N and S draw to it the lines N C',
S C', which should be produced a little beyond C' ; and de-
scribe from the centres N and S, respectively, the small arcs
C A and C B to meet these lines. Draw also C E perpendi-
cular to N T. Let the same notation as before be preserved
with regard to w, s, p and q.
* The following is a convenient way of obtaining, geometrically, lines which
are in the ratio of the cubes of two given lines, A B and A C, Fig. 2. Set them,
Fig. 2.
as in the Figure, at right angles to one another. Join B C, and draw A D per.
pendicular to it. Draw C E, and D F, parallel to A B j and D E parallel to A C.
The lines D F, DK, will be to one another in the ratio of the cubes of AB
and AC.
314 Dr. Roget on the
Let C E = e
CA = a
CB = b
The angle C N T = «
The angle C S T = £
Cosine of a = c
Cosine of /3 = x
Then d cc = — : and the triangle CAC' being similar to NPC
n
n : p :: t : a; or a = t £-
n
n : e :: da. : dc.
j doc a , p
dc = e — = e — — e t J—
n n* n* '
By a parity of reasoning dx = e t JL
s3
Therefore dc:dx::JL:JL::R:r.
w3 s3
When R = r, d c = d x. Hence c = x + C, or c — x = C.
That is, the difference between the cosines of the polar
angles C N T, C S T, is a constant quantity.
When the angle C S T exceeds a right angle, its cosine
being then negative, the proposition will be changed to the
following ; namely, that the sum (instead of the difference) of
the cosines of the polar angles is constant. When the angle
C N T is also obtuse, both the cosines being negative, it is
again the difference of the cosines that is constant.
The following method of describing this curve is derived
from the property above demonstrated. Let the two radii Nn,
S s, Fig. 4. be taken of equal length, and be made to revolve
in the same direction round their respective centres N and S,
while their other extremities n and s are always kept in such a
position relatively to each other, as that a Jne drawn through
them shall remain perpendicular to the axis N X ; then the
line constituted by the successive points of intersection C, c',
&c. of the two radii, will be a magnetic curve. This will
appear from the consideration that with the equal radii N?z
and S n, the cosines of the angles C N X and CSX are the
lines N X and S X, of which the difference is N S. In every
other position of the radii, as N ri, S s1, where the line s' n' x'
Geometric Properties of the Magnetic Curve. 315
Fig. 4,
is perpendicular to the axis N a?', N S is the constant differ-
ence between the cosines of the polar angles c' N x and c S x.
When C S X is an obtuse angle, as in Fig. 5, the cosine of its
Fig. 5.
supplement C S N (or SX) added to that of C N S (or N X),
will, in like manner, be found to give the constant sum N S,
provided the other extremities, n and s, of the revolving radii
continue to be in a line perpendicular to the axis ; as will
readily appear by inspecting the figure.
On this principle I have contrived the following instrument
for describing mechanically the magnetic curve.
The ruler N n, Fig. 6. is furnished with a sliding collar,
which, by means of a screw, may be fixed at any point in its
length. The collar has a hole at the edge of the ruler, for the
passage of a pin, which fixes it to a board (previously covered
with a sheet of paper), at the point intended as the pole N ;
so that the ruler may turn round this point as a centre.
316
Dr. Roget on the
Fig. 6.
Another ruler AB, of equal length to the former, being furnished
with a similar collar, is made to revolve round A, at the extre-
mity of the line A N, which is perpendicular to the axis N S.
The other ends, B and ?i, of these two rulers, are connected by
a third (equal in length to N A), which, during the movements
of N n and A B, preserves its parallelism to N A. The ruler
B n has a groove, running its whole length, in which a button,
projecting from the extremity of the rule S s, slides. The
ruler S.s is also furnished with a collar similar to the former,
which fixes it to the board at S, or at any other required point
in the line N S. A pencil, following the intersections of the
rulers N n and S s with each other, as they turn round their
respective centres N and S, will describe a magnetic curve. In
adjusting the several collars, care must be taken that the dis-
tances of A, N, and S from B, n, and s, respectively, are all
equal ; and, in order to effect this, it will be convenient to
have the rulers graduated to a scale of equal parts. The
greater these distances, the larger will be the curve described
by the instrument. When the ruler N n is brought down so as
to coincide with the axis N S, the other ruler S s is in the
Geometric Properties of the Magnetic Curve. 317
position of the tangent to the curve at its origin from the
pole S.
When the two poles which give rise to the magnetic curves
are of the same, instead of being of different, denominations, a
different system of curves is produced, which have been termed
the divergent, in contradistinction to the former, which are
convergent to the poles. The divergent curves preserve, with
slight modifications, the same geometrical relations to the axis
as the convergent curves, and admit of a similar mode of
mechanical description. Instead of the south pole S, in the
preceding figures, let another north pole N' be substituted;
thai is, let the north poles N, N', Fig. 7, of two different mag-
Fig. 7,
nets, be placed so as to front each other ; and let the actions
of their remote south poles be neglected. In the former case,
where the actions of the two poles of the magnet were of an
opposite kind, the resultant of their joint action, or the line
CT, Figs. 1 and 3, passed in a direction intermediate between
N C prolonged, and S C (the former line being the direction of
the repulsion, and the latter that of the attraction) : it there-
fore cut the axis N X at some point in the prolongation of
N S. But in the present case, the two magnetic poles being
of the same kind, their action is similar, and their resultant is
a force, of which the direction is intermediate to the lines
C N and C N', Fig. 7. ; and this line produced, must cut the
axis somewhere between N and N'. The angle C N' T being
reversed from the situation with respect to C N', which it had
in the former case, the sign of its cosine must be changed,
and the equation becomes
c + x = C.
VOL. I. FEU. 1831. Y
318
Dr. Roget on the
This applies to the case, in which the angle formed by C N'
with the produced axis is acute, and its cosine positive. When
it is obtuse (or C N' N acute), its cosine being negative, the
equation is
c - x = C.
When the two poles are similar, and consequently the
curves divergent, the two radii, which, during their revolution,
generate them by their intersections, revolve in opposite direc-
tions ; and the points in each which preserve the same perpen-
dicular position with relation to one another, will be found to
lie on opposite sides of the axis. The intersections of N n
are made with that portion of the line S s, which is produced
on the other side of the pole S. This is shown in Fig. 8,
Fig. 8.
where N, P, are the two similar poles, and Nw, Pjp, the
two revolving radii ; the latter being produced beyond P to q.
In this position, when N n coincides with the axis, P q is the
direction of the tangent to the divergent curve at the pole P.
In their positions N n and Pp', the radii intersect one another
at the point c'; when they arrive at n" andp", they intersect
at c" ; and so on ; P, c', c", &c., being so many successive
points of the curve. When N n and Pp become parallel, they
indicate the ultimate direction of the curve.
Geometric Properties of the Magnetic Curve. 319
The divergent magnetic curves are capable of being de-
scribed by an instrument of a similar construction to the one
already explained ; only the ruler B n, Fig. 6, must be of
twice the length of the former ; and in order to obtain a suffi-
cient extent of curve, the revolving rulers, N n> and S s, must
be prolonged in those parts where the intersections are to take
place.
ON THE FIRST INVENTION OF TELESCOPES, COL-
LECTED FROM THE NOTES AND PAPERS OF THE
LATE PROFESSOR VAN SWINDEN.
BY DR. G. MOLL, OF UTRECHT.
[Communicated by Professor Moll.]
PHE late Professor Van Swinden had been at considerable
pains to illustrate some important points in the history
of natural philosophy. The first invention of telescopes in
Holland attracted a considerable share of his attention, and he
had the good fortune to meet with some official documents,
which are calculated to throw some light on the mystery in
which the early history of this celebrated invention is involved.
Mr. Van Swinden exposed the result of his labours in several
public lectures, and he intended to publish a paper on the
subject : his death prevented the accomplishment of this
purpose. He left, however, the sketches of his lectures, toge-
ther with extensive notes, and abstracts from various writers,
which he had collected with great industry. These papers
were committed to my hands, and the result of what I collected
from them has been ordered to be printed by the Royal Insti-
tute of the Netherlands.
The little which is known of the first invention of telescopes
in this country has been principally derived from two sources :
first, from the book which the French physician, Pierre Borel,
wrote on the subject in 1655, probably at the request, and
certainly with the assistance, of William Boreel, at that time
ambassador of the States at the court of France*. The second
* De vero Telescopii inventore, cum brevi omnium Conspicilliorum
historia, authore Petro Borello, Regis Christianissimi consiliario et
medico ordinario; Hagse Comit. ex typogr. Adriani Vlacq. 4to., 1655.
Y2
320 Dr. Moll on the Invention of Telescopes.
source from which information is generally derived, is a passage
in Descartes's Dioptrics*, in which he attributes the invention
to a citizen of Alkmar, called James Metiiis. Both the versions
of Borel and Descartes are usually given in books written on
this part of natural philosophy, and very recently they were
repeated in the very excellent account of the life of Galileo
published in England, and in the still more recent and capital
work of Professor Littrow on Dioptrics.
The real name of this Metius, of whom Descartes speaks,
and who is also mentioned by Huygens, was Jacob Adriaansz.
His father Adriaan Anthonisz was a man of considerable know-
ledge for his time; he possessed a great influence, and took a
principal part in the struggle with Spain. In consequence, he
was banished by the Duke of Alva, and his property confis-
cated. He contributed very essentially to the glorious defence
of his native town against the Spaniards in 1592. He was
created afterwards inspector of fortifications, and many towns
were fortified on his plans. As a mathematician he is cele-
brated for his expression of the ratio of the diameter and cir-
cumference of the circle, by the numbers 113 and 355. At
that time Ludolf van Ceulen had not given his celebrated num-
ber, and the ratio of Archimedes, of 7 and 22, was in general
use. The numbers of Anthonisz have the merit of being easily
kept in memory, and of being as accurate as almost any pur-
pose requires. If no logarithms are used, it is easier to calcu-
late than Ludolf's number.
There is another problem remaining of this Anthonisz, which
shows his ability as a mathematician : it is recorded in one of
the writings of his son Adrian, and Delambre notices it in his
history of astronomy, The problem was solved by Nicholas
des Muliers of Bruges, then professor of mathematics in Gro-
ningen.
All the four sons of Adriaan Anthonisz were mathematicians
like their father. The eldest, Dirk or Theodore, was an engi-
neer and surveyor in the service of the States. He sailed in
Pierre Borel was a native of Chartres, and author of several other books :
he died 1689. A copy of this very rare tract has been recently added to
the library of the Royal Institution. It contains a portrait of Lippershey.
* Cartesii Dioptrica, p. 49.
Dr. Moll on the Invention of Telescopes. 321
that capacity in the expedition against the Spanish colonies in
the West Indies and the coast of Africa, sent out under Admiral
Peter Van der Does in 1599. He died in that ill-fated expe-
dition.
The second son, Adrian, whilst at the University, had the
nickname of Metius given to him by his fellow-students, on
account of his propensity to mathematics. He became gene-
rally known under that name, and wore it through life. His
father sent him to Hueen to study astronomy under the cele-
brated Tycho, and afterwards he visited several universities of
Germany. He filled the astronomical chair at the university
of Franeker with great credit, and died in that place in 1635.
His works were very numerous and celebrated in their time,
being considered the best elementary works then extant.
Delambre seems to have known only one of Metius's books,
of which a complete catalogue is to be found in Yriemoet*.
The fourth son, Anthony, did not rise to such extensive
fame : however, he also served his country as an engineer.
The third son is the person whom Descartes designates as
the inventor of the telescope. His name was Jacob Adriaansz ;
and sometimes the name of Metius, which properly belonged
to his brother, was given to him. This Jacob, or James, died
between 1624 and 1631. Contemporary writers describe him
as a person of eccentric and fanciful habits, buried incessantly
in deep meditations, and of a temper so little communicative,
that he very seldom spoke to any one about the subject of his
studies. It is well known that such an eccentric turn of mind
is not incompatible with mechanical genius, and in England
and elsewhere the most consummate skill has often been
blended with most singular habits. It appears, from the evi-
dence of writers of that time, that this Jacob had acquired
considerable skill in working glass, and excelled, amongst
other things, in the construction of large burning lenses. It is
said that he once placed a large lens on the walls of Alkmar,
and predicted that at a certain hour of the day it would set fire
to a tree standing at a great distance on the other side of the
moat. At the request of Prince Maurice of Nassau, who was
* Athena* Frisiacae,
322 Dr. Moll on the Invention of Telescopes.
a great proficient in mechanics and mathematics, many and
pressing solicitations were made to make Jacob explain how
this and other apparatus which he contrived were executed ;
but he obstinately rejected all offers, and always refused to give
the least information, even on his death-bed, when strongly
urged by a clergyman, at the request of his relatives. It must
be allowed that at that time, and even now, the construction of
a burning lens of such power was a matter of great difficulty,
and even at present very few artists would be capable of doing
the same. So strongly was his desire to conceal his inventions,
that before his death he caused his apparatus and tools to be
destroyed.
This eccentric character sent a petition to the States General
of the United Provinces, dated the 17th of October, 1608. An
original copy of this document, made by a public notary in the
most authentic form, is existing in the library of the university
of Leyden, amongst the manuscripts of Huygens. In this
document it is distinctly asserted that this person actually
invented the telescope. He calls himself Jacob Adriaanszoon,
son of Mr. Adriaan Anthoniszoon, and he goes on to state,
' that since two years, he employed all the time which he could
spare in inquiring into some occult or secret arts connected
with glass-making. That he found that, by means of a certain
instrument, which he was making for another purpose, the
sight of persons using it might be extended, so as to make
objects which, on account of their distance, could not be seen
or only distinguished with great difficulty, appear near and
distinct. That since that time he applied himself to bring this
invention to greater perfection, in which he succeeded so far as
to make an object appear as visible and distinct by his instru-
ment as can be done with that which was lately offered to the
States by a citizen and spectacle-maker of Middelburg. That
his Excellency (Prince Maurice), and others who compared the
instruments, convinced themselves of this fact, notwithstanding
that his instrument was made of only coarse materials, and
merely for the sake of experiment. That he has no doubt but
that the contrivance, by improving the engine, might be brought
to greater perfection, but that, besides, he believes and hopes to
improve, in time, the invention in itself, so as to make it capable
Dr. Moll on the Invention of Telescopes. 323
of doing great service. That he apprehends that, in the mean-
time, other persons might imitate his invention, building on the
foundations which he had laid, by the grace of God, with his
ingenuity, great labour, and intense study, and by these means
might frustrate him, and rob him of the fruits which he has a
right to expect with great confidence of this invention ; and,
therefore, he prays their High Mightinesses to grant him a
privilege (octroi), by which every one, not possessing the said
invention at present, is prohibited from imitating this instru-
ment, or even from selling or purchasing instruments made
contrary to this privilege, without his express leave, and on a
fine of a hundred florins on each instrument; and that this
privilege is to last twenty years, or, instead of a privilege, to
allow him [such a remuneration as will be adequate to the
utility and service likely to be derived from this invention.'
In the margin of the petition the following appointment is
written : — ' The petitioner is exhorted to make further investi-
gations, to bring his invention to greater perfection ; when his
prayer for a privilege will be taken into consideration.
' Actum, 17 October, 1608.1
With the signature of « Aersens/ the then Secretary of the
States.
If we are disposed to give full credit to Adriaansz, whom,
for brevity sake, we will call Metius in future, it appears that
he began the researches which led him to the invention of the
telescope as far back as 1606 ; that the invention was due to
chance, and occurred while its author was trying other experi-
ments ; that he spent subsequently much time and labour upon
it ; but that in 1608, when he sent in his petition, his instru-
ment was made of bad materials, and might be much im-
proved. At the same time he readily admits that another
person, a spectacle-maker of Middelburg, had offered before
him a similar instrument to the States, which had been tried
by Prince Maurice and other persons, and he gives us to
understand that his instrument is equal to that of his compe-
titor. Nothing is said which enables us to judge of the per-
formance of either instrument.
Mr. Van Swinden examined the written Acts and Journals
of the States-General of that time with great care. These
324 Dr. Moll on the Invention of Telescopes.
papers are kept at present among the state archives in the
Hague. Under date of the 2d October, 1608, the following
entry is made : —
'Jovis, 2 October, 1608.
4 On the petition of Hans Lippershey, a native of Wesel,
an inhabitant of Middelburg, spectacle-maker, inventor of an
instrument for seeing at a distance, as was proved to the
States, praying that the said instrument might be kept secret,
and that a privilege for thirty years might be granted to him,
by which everybody might be prohibited from imitating these
instruments ; or else to grant him an annual pension, in order
to enable him to make these instruments for the utility of this
country alone, without selling any to foreign kings or princes.
It was resolved, that some of the Assembly do form a com-
mittee, which shall communicate with this petitioner about his
said invention, and inquire of him whether it would not be
possible to improve upon it, so as to enable one to look through
it with both eyes,; and further, to inquire what remuneration
would satisfy him. And due report .being made, it will be laid
in deliberation, whether it is expedient to grant to the peti-
tioner a remuneration or a privilege.'
From this document it appears who this inventor was, whom
Metius designates in his petition of the 17th of October, and
whom he allows to have anticipated him in presenting a
telescope to the States: it was the spectacle-maker of Middel-
burg, bom at Wesel, and called Hans, L e. John Lippershey.
This man offers to keep his invention a secret ; and he inti-
mates a belief that it might be of service. This story offers
also a ludicrous instance of the strange vexations to which
ingenious men must often submit, from ignorant but official
persons ; this is —
' The insolence of office, and the spurns
That patient merit from the unworthy takes.'
• Here comes Lippershey, tendering to the States an inven-
tion, which, in its further progress, is entirely to alter and to
extend all our notions of the universe — an invention which
bodes a complete revolution in navigation and astronomy, and
the first thing which these wise men think of, is to lay the
Dr. Moll on the Invention of Telescopes. 325
inventor under the obligation of making a telescope through
which one could see with two eyes.
Two days afterwards, the 4th of October, 1608, we find the
following entry upon the Journals of the States : —
' Sabathi, 4 October, 1608.
* Resolved, that inclusive of the communication held the 2d
instant with Hans Lippershey, a native of Wesel, inventor of
the instrument to see at a distance, one person from each pro-
vince will be named, to examine and to try the said instru-
ment on the turret of the mansion of his Excellency (Prince
Maurice) , and to investigate whether it is likely to be of such
utility as is generally believed ; and, in such a case, to treat
with the inventor, that he undertakes to make three such
instruments of rock-crystal (christael de roche), for which he
asks a thousand florins a-piece ; that he moderates his charge,
and promises never to transmit his invention to anybody.'
In this piece we have the counterpart of what happened to
Galileo at Venice. Here we have the members of the States-
General ascending the turret on Prince Maurice's house, to
examine a distant object with the newly-invented spy-glass, as
the Venetian senators mounted the steeple of St. Mark ; and
probably Lippershey was equally tired as the Italian philoso-
pher, with snowing off his instrument to persons requiring
telescopes to make them see with two eyes.
The mention which, in this early stage of the invention, is
made of rock or mountain crystal, appears very curious. It
seems that, in this beginning, the difficulty of procuring glass
fit for telescopes was equally as great as it is now, and rock
crystal was frequently resorted to, in the constructiom.of object-
glasses. This appears, amongst others, from a passage in
Hevelius, who, however, gives the preference to glass. At this
present day the Parisian optician, Cauchoix, constructs tele-
scopes of rock or mountain-crystal, which he calls lunettes
vitro-crystal lines ; but which, in my opinion, are inferior to
glass telescopes of equal size. One consequence may be
deduced from the circumstance of rock-crystal being used in
the construction of these telescopes, which is, that this spec-
tacle-maker must have been well skilled in his profession,
326 Dr. Moll on the Invention of Telescopes,
inasmuch as it is much more difficult to work and to select
crystal than glass.
The 6th of October following, mention is made again in
the Acts of the States, of the subject of telescopes : —
October, 1608.
' The Commissioners of the Provinces who have examined
the instrument made by John Lippershey, spectacle-maker,
and who have communicated with him, report that the instru-
ment is likely to be of utility to the state, and that in conse-
quence they offered to the inventor to make such an instru-
ment of rock-crystal for the state, at the price of three hundred
florins, payable immediately, and six hundred florins more
when the instrument is completed arid approved of. Resolved,
to authorise these gentlemen, as is done by the present, to
come to a final conclusion with Lippershey, about the making
of the said instrument, and to limit him a time within which
the instrument is to be completed and delivered in good order.
And then the States are to deliberate whether a privilege or an
annual pension is to be granted to the petitioner, under condi-
tion, that he will promise to make no such instruments, but
with the consent of the States.'
Whilst these transactions were taking place with Lippershey,
Metius, the second competitor, handed in his petition the 17th
of October. Having gone so far with Lippershey, the States
were perhaps at a loss how to dispose of Metius's claim. They
contented themselves with giving him some empty words of
encouragement, and some vague promises for the future.
After this time nothing more was done by Metius to attract
public notice. He doggedly refused to show his telescopes to
anybody, not even to Prince Maurice, and least of all to his
brother, the Professor of Franeker. Perhaps Jacob Metius
was disgusted with the little encouragement he received, and
it is not unnatural to suppose, that a man of his eccentric
habits, having once failed in his object, could not make up his
mind to make a second attempt.
The petition of Metius appears, however, to have had some
influence on the manner in which the petition of Lippershey
was disposed of.
Dr. Moll on the Invention of Telescopes. 327
We next find the following notes on the Record Book of
the States-General : —
* Jovis, Uth December, 1608.
' The petition is read of Hans Lippershey, spectacle-maker,
inventor of a certain instrument for seeing distant objects :
no resolution has been taken on it, but Messrs. Van Dordt,
Magnus, and Vander Aa, are appointed to speak with the
petitioner about the said invention.'
1 Luncz, 1 5th December, 1608.
' Messrs. Magnus and Vermanne report, in the absence of
Messrs. Vander Aa and Boeles, that they examined the
instrument invented by the spectacle-maker, Lippershey, to
see at a distance with two eyes, and that they approved of it ;
in consequence of which it was proposed whether the privilege
ought to be granted to the said Lippershey, of making alone
the said instrument for a certain number of years, and to pay
him the remaining six hundred florins which were promised
him for the said instrument. Resolved, that whereas it ap-
pears that many other persons have a knowledge of this new
invention, to see at a distance, it is expedient to refuse the
prayer of the petitioner for an exclusive privilege, but that he
will be commanded to make, within a certain time, two other
instruments of his invention, for seeing with two eyes, for the
same price ; and checks are to be despatched to him for three
hundred florins, and when the instruments are completed, of
six hundred florins.'
Lippershey used no delay in making the instruments, thus
setting an example which the most eminent in his profession
are said not to have always followed. The next mention is
made of Lippershey in February, 1609.
' Veneris, 13th February, 1609.
' Hans Lippershey delivered the two instruments for seeing
at a distance, which he was ordered to make, and in conse-
quence it has been resolved to despatch checks of the three
hundred florins remaining of the nine hundred which were
promised him for three of the said instruments/'
From these documents it appears that both Lippershey
328 Dr. Moll on the Invention of Telescopes.
and Metitis failed in their attempt of obtaining an exclusive
privilege. But certainly the instruments of the former were
liberally paid. Nine hundred florins, or 75£., for an instru-
ment such as it can be expected to have been at that time, is
certainly a high price ; and even at the present time a very
respectable telescope could be obtained for that money. From
this circumstance, we would be rather inclined to argue, that
these instruments were not so roughly made as Italian authors,
and those who follow them, are willing to persuade us. Our
thrifty forefathers were too prudent and too economical to
throw away considerable sums of the public money on things
of bad manufacture arfd rough making.
Italian writers generally represent the Dutch telescopes as
very imperfect. But how do these writers know this? Has
Nelli, or any other, ever seen one of the telescopes of that
time? If not, how can they judge of their performance?
There is not the least necessity, in order to value the tran-
scendent genius of a Galileo at its proper standard, to de-
preciate the merit of others ; and we may admire Galileo
without being unjust towards his contemporaries.
It is very remarkable that the absurd wish of the States to
have an instrument which would enable them to see with two
eyes, should have led to the invention of an instrument which
has at present fallen into undeserved oblivion, It appears
from the official documents, that Lippershey, indeed, gratified
the wishes of the States, and that he produced an instrument
with which they could see with two eyes. There can be little
doubt but that this instrument was what was called afterwards
a binoculus. The invention of this instrument is generally
attributed to the Capucin friar, Rheita *, who describes it in
one of the most singular books which ever were written.
For terrestrial objects a well-arranged binoculus is perhaps
the most pleasant telescope, but some dexterity is wanted to
bring it to proper adjustment. It shows the objects con-
siderably brighter and more distinct than a common telescope
* Oculus Enoch et Elise, sive Radius siclereo-mysticus planetarum, An-
twerpiac, 1645, fol. p. 338, 354. See also Dioptrique Oculaire par le Pere
Cherubiu Le GentiJ, Mtmohes de 1' Academic des Sciences, 1787. Smith's Optics,
p. 974.
Dr. Moll on the Invention of Telescopes. 329
of equal power ; and it has the great advantage of not straining
and fatiguing the eye.
The readiness with which Lippershey furnished the States
with the binoculus is a proof of considerable ingenuity, and
must tend to do away with the notion that he was a low,
ignorant mechanic, guided by mere chance.
The States, refusing to grant the privilege which Lippershey
wished to obtain, give as a reason of their refusal that the
invention was known to many. Of this we have evidence in
Metius's petition ; but we may find some more, in a book
from which one would little expect to draw scientific infor-
mation.
Negotiations, which terminated in a twelve years' truce,
were then pending in the Hague, between the States and
Spain. The ministers of the King of France, Henry IV".,
were the celebrated President de Jeannin and .Monsieur Bussi.
The letters which Jeannin wrote on the subjects of these
negotiations to the king and his ministers have been printed,
and amongst them we find something relating to the history of
the invention of telescopes*.
Thus on the 28th of December, 1608, a few days after the
States had refused the privilege to Lippershey, Teannin and
Bussi write to the king.
' The bearer, who returns to France, is a soldier of Sedan,
who served some time in Prince Maurice's company j\ He
possesses several inventions for the war, and that form of
glasses (the French has lunettes} which have recently been
invented in this country by a spectacle-maker of Middleburg,
by which one sees at a great distance. The States ordered
the workman, who is the inventor of them, to make two for
your majesty. We should not have required their favour, if the
artist had been willing to make them at our own request ; but
he refused, saying, that he had express orders from the States,
not to make them for anybody. We will send them to your
majesty on the first opportunity; and notwithstanding this
soldier makes themasjvvell (aussi-bien) as the other, as appears
* Lettres et Negotiations du President de Jeannin. Paris, fol. 1656.
f In the Prince's guards.
330 Dr. Moll on the Invention of Telescopes.
by the trials which he made, still the difficulty of making them
is not great.'
The same day the President writes to the Minister Sully :
* The bearer of this letter is a soldier from Sedan, who
belongs to the prince's company, and who is held very in-
genious in many inventions and artifices of the war. He has
also made, a few days ago, an engine (un engin), in imitation
of that which has been made by a spectacle -maker of Middel-
burg, to see at a distance. He will show it to you, and make
you some for your sight. I requested the first inventor to
make me two, one for the king, and one for you; but the States
prohibited him from making any but for themselves. They
ordered some themselves to give them to me, that I may send
them to you, which I will do the first day.'
The king's reply is very remarkable, being written about a
year before that prince was murdered at the instigation of the
Jesuitical faction. He writes thus the 8th of January, 1609 :
1 1 shall see with pleasure the glasses which you mention in
your letter, though at present I am more in want of such that
can show me things near me, than of those which show distant
objects.'
Having thus shown what are the respective claims of Metitis
and Lippershey, we must now consider those of a third pre-
tender to the honour of the invention. This person was also
a spectacle-maker of Middelburg, called Zacharias Tansz, and
he has, more generally than Lippershey, been considered as the
original inventor. The information of what we know about
him must be wholly derived from Borel's book on the invention
of telescopes. William Boreel, who appears to have been
very anxious about this matter, being himself a native of
Middelburg, had all the persons then living, and knowing
something on the subject, examined before the magistrates in
1655. Their depositions are given in Borel's book ; but the
originals of these depositions have not been found in the records
of the town of Middelburg, although a very diligent search was
made for them. In these documents, the places and houses in
which both Lippershey and Zacharias Tansz lived, are fre-
quently mentioned. These houses have since been taken
Dr. Moll on the Invention of Telescopes. 331
down, and an open space now occupies the place where the
telescope was invented.
Some of the witnesses, whose evidence is given in Borel's
book, are in favour of Lippershey, and some in that of Zacha-
rias. We must now carefully sift that evidence, and com-
pare it with what Borel says on the subject, in a letter to
Pierre Borel.
The first witness who occurs on the list is John Willems, a
steward or beadle. He is seventy years of age, in 1655, and
knew Lapprey personally when he made spectacles. Afterwards
he made telescopes (tubos longos), which he did about fifty
years, when Lapprey offered the first telescope to Prince Mau-
rice, as he (the witness) heard at the time.
This witness brings the invention down to 1605, but he does
not appear to have had a very clear recollection of the exact
time of the invention.
The second witness is Edwold Kien. He is a messenger,
aged sixty-seven ; says that the man who made the telescopes was
John Laprey, of Wesel ; that he began making telescopes about
1610, and died in October 1619. He (the witness) married
the daughter of this Laprey. Laprey offered to Prince Mau-
rice and to the States some of his telescopes, for which he got
a reward, and a privilege for three years. He adds, that the
sign of the house where Laprey lived was a telescope.
From a comparison of dates, it is obvious that this witness is
mistaken, and that Lippershey made telescopes, and offered
them to the States long before 1610.
The third witness is a blacksmith of the name of Abraham
Junius, aged, in 1655, seventy- seven. He says, that the name
of the man who first made telescopes in this town was Hans,
i. e. John, but that he did not observe the surname ; that this
man was commonly called John the spectacle-maker; that
about forty-five or forty-six years ago this John made the first
long telescopes (conspillia longa) ; that the witness knew him
long ago, before he made spectacles, when he was a bricklayer ;
he assisted at the funeral of John ; he knows, and heard very
often that John made long tubes (tubos longos) and telescopes
for the use of Prince Maurice.
This witness brings the invention to 1609 or 1610, and very
little is to be concluded from his evidence.
332 Dr. Moll on the Invention of Telescopes.
The Capucin friar, Uheita*, attributes also the first invention
to Lippershey, whom he calls Lippensum. This is certainly no
great alteration of the original name, not greater than that
which is made by the English author of the Life of Galileo, who
chooses to translate Borel's name into Italian, and calls him
Borelli. According to the version of Rheita, the invention
dates from 1609, when Lippershey happened to place a convex
before a concave, and discovered, by chance, that the weather-
cock of a neighbouring church, and other objects, were magni-
fied. He placed his glasses in a tube, and amused the visiters
of his shop by showing them the weather-cock magnified, and
larger than it could be seen with the unassisted eye. The
Marquess of Spinola, happening to be at the Hague at the time,
to negotiate about the truce, saw this new instrument, bought it,
and gave it to the Archduke Albert of Austria, the Spanish
Governor of Belgium.
In the mean time, persons of high station (proceres) heard
of the circumstance, and that other similar instruments had
been constructed by the maker. The inventor was forced to
sell his instrument for a great price ; but he was prohibited
from making or selling any more of them. In this manner,
says the worthy friar, this noble and capital invention would
have remained in obscurity, and hidden perhaps for ever, if it
had not been transferred, by the will of God, to the court of
Brussels, and made known there.
The Capucin friar is mistaken in the dates, bringing the
invention to 1609 instead of 1608. But, besides, the Marquess
of Spinola was not at the Hague in 1609. He left that city the
30th of September, 1608, together with the other Spanish mi-
nisters. That he left the Hague a little before Lippershey pre-
sented his petition to the States ; but the Marquess, residing
at the Hague, certainly could not see an apparatus which a
spectacle-maker had erected in his shop at Middelburg ; but, at
all events, there is a possibility that Spinola, residing at the
Hague in September, 1608, heard of the invention, and pro-
duced a telescope for the Archduke.
* Oculus Enoch and Eliae, p. 337.
(To be continued.)
( 333 )
Proceedings of the Royal Institution of Great Britain.
FRIDAY EVENING MEETINGS.
Jan. 21st. — THE meetings for the season commenced this evening,
and will be continued every Friday, except those of Passion and
Easter weeks, until the 10th of June. The subject in the lecture-
room, upon the present occasion, was given by Mr. Faraday, being,
in fact, the developement and illustration of that peculiar class of
optical deceptions which forms the object of the first article in the
present Journal, p. 205. The effects were shown by large wheels
cut out of pasteboard : those produced, by casting the shadows of
the moving wheels upon a screen, were exceedingly well exhibited
by means of the cone of rays from a magic- lantern. The appear-
ances exhibited by reflection were also well shown ; and, as some
effects beyond those mentioned in the paper had been observed,
and were explained, Mr. Faraday will add a note of them at the end
of these proceedings.
In the library, Mr. Cuthbert showed the power of his beautiful
microscope, by exhibiting some wheel animalculae ; and Mr. Varley
also exhibited more of these animals, by means of excellent micro-
scopes in his possession ; the object was to give the members an
opportunity of seeing the appearance of this curious creature, that
they might the better understand the references made to it by
Mr. Faraday, in pursuance of his subject.
Numerous presents of specimens of natural history, books, en-
gravings, &c. &c. were laid upon the library-table. Mr. Pepys
brought to the meeting a very beautiful piece of American glass
casting ; it was a small plate, the upper surface smooth, but the
under surface covered by a beautiful design of scroll-work, &c. in
very high relief, so that, as the plate stood upon a table, the reflec-
tion of light from it was of the most brilliant and metallic kind. The
plate had been cast, the wheel had never touched it, yet the surface
VOL, I. FEB. 1831, Z
334 Proceedings of the
looked as well almost as if cut ; and the pattern was so rich and
full, and of such a kind, as to preclude any imitation of it by
cutting. Mr. Pepys also placed a beautiful spiral metallic thermo-
meter, by Breguet, upon the table.
NOTE BY M. F.
In consequence of the necessity I was under of sending the paper
referred to in the above proceedings to press (page 205) by a
certain time, I was unable to pursue many of the beautiful com-
binations of form, colour, and appearance, to which the experi-
ments led, especially as they promised only amusement and little
more of instruction than the paper itself contained ; but one or
two varieties in the appearances, which have occurred to me since,
are so striking, that I am glad of the opportunity of noticing
them briefly in the same number with the paper. At page 218,
I have described the singular appearance produced when the
reflected image of a revolving cog-wheel, held before a glass, is
observed through the cog-wheel itself. If, in such a wheel, a little
nearer the centre, a series of regular apertures be cut, so as to re-
present cogs and their intervals, but the number different by 1.2.3,
or any small quantity, from the number of the cogs, then, upon
making the experiment as before, that series of cogs in the re-
volving wheel through which the eye looks will appear to stand
still, but the other series will travel in the spectrum : upon changing
the eye to the other series of apertures, then the quiescent part of
the spectrum will move, and the moving part become quiescent.
If two or three series more of such apertures be cut in the wheel,
concentric one to another, but the number of intervals varying in
each, then a great variety of changes are produced, as the eye looks
through one part or another of the wheel. The series of cogs in the
spectrum move with different velocities, or in opposite directions,
changing with the slightest motion of the eye. Two or three per-
sons looking through different parts of the wheel see appearances
Royal Institution of Great Britain. 335
entirely different ; yet all these deceptive appearances result from a
single reflection of a single wheel, moving in a constant direction
and with uniform velocity.
By the application of colours and coloured foils, very curious
effects occur, which are endless in their variety. As an illustration,
let a wheel with a single series of cogs at the edge, and with inter-
vals equal to the cogs, have a circle of colour applied between the
cogs and the centre of the wheel ; let the part below the cogs be
green, and the part below the spaces red ; the coloured circle will
consist of green and red alternately. If this wheel be revolved
before the glass; the green and red mingle, and the reflection
observed in the ordinary way will exhibit one uniform colour ; but
if the reflection be observed from between or behind the cogs, the
green and red immediately separate, and besides having the
appearance of fixed cogs, there is also the appearance of fixed
unmingled colours. If the interval be equal to only half a cog,
and three colours be applied, the three colours may, after being
mingled by rotation, be again developed, and it is easy in this way to
separate many colours from each other. The experiment in illus-
tration of Newton's theory of colour, by painting the head of a top
and spinning it, is well known ; by the means just described the
experiment can be still further extended, and the colours separated
one from another, even while the whole system remains in motion.
The combination of other forms than wheels by the apparatus
described, page 208, produces very beautiful effects. The applica-
tion of colours here also is so evident as to need no illustration.
The variation of the proportion of the interval to the remaining
pasteboard causes many curious appearances, especially when the
shadows produced in sun-light are observed.
Since the printing of the paper, a friend has referred me to the
article * Animalcula,' in Brewster's Encyclopedia, where an.
opinion on the appearance of these creatures is given, nearly the
same as that I have ventured. Speaking of the opinions of those
who suppose them to be true revolutions, it is said, * Yet notwith-
Z 2
336 Proceedings of the Royal Institution.
standing our respect for the skill and talents of such renowned
naturalists, we cannot deny that we think the production of the
vortex is more probably effected by the simple motion of the
fibrilla — that it may ensue from their rapidly bending in regular or
alternate succession, or by some analogous means.'
M. F.
( 337 )
ANALYSIS OF BOOKS.
Philosophical Transactions of the Royal Society of London,
for the year 1830. Part II.
1. Memoir on the occurrence of Iodine and Bromine in certain
Mineral Waters of South Britain. By Charles Daubeny, M.D.,
F.R.S., Professor of Chemistry in the University of Oxford.
[Read May 6, 1830.]
'T'HE author lays claim to being the first who announced to the
public the existence of bromine in the mineral springs of Eng-
land ; a discovery similar to that which had been previously made
by others in many analogous situations on the Continent. His reason
for offering the present communication to the Royal Society is, that
he has examined on the spot a great number of mineral springs,
and endeavoured to obtain, wherever it was practicable, an approxi-
mation to the proportion which iodine and bromine bear to the
other ingredients. He has also aimed at forming an estimate of
their comparative frequency and abundance in the several rock
formations ; an object of considerable interest in geology, as tending
to identify the products of the ancient seas in their most minute par-
ticulars with those of the present ocean. The results of his inquiries
are given in the form of a table, in which the springs, whose waters
he examined, are classified according to the geological position of
the strata from which they issue, and of which the several columns
exhibit the total amount of their saline ingredients, the nature and
proportion of each ingredient, as ascertained by former chemists, or
by the author himself; and lastly, where they contained either iodine
or bromine, the proportions these substances bear to the quantities
of water, and likewise to the chlorine also present in the same
spring. He finds that the proportion of iodine to chlorine varies in
every possible degree, and that even springs which are most strongly
impregnated with common salt, are those in which he could not
detect the smallest trace of iodine. The same remark, he observes,
applies also to bromine j whence he concludes, that although those
two principles may perhaps never be entirely absent where the
muriates occur, yet their relative distribution is exceedingly unequal.
The author conceives that these analyses will tend to throw some
light on the connection between the chemical constitution of mineral
waters and their medicinal virtues. Almost the only two brine
springs, properly so called, which have acquired any reputation as
medicinal agents, namely, that of Kreutzriach in the Palatinate, and
that of Ashby de la Zouche in Leicestershire, contained a much
larger proportion than usual of bromine ; a substance, the poisonous
quality of which was ascertained by its discoverer, Balard. The
338 Analysis of Books.
author conceives that these two recently-discovered principles exist
in mineral waters, in combination with hydrogen, forming the
hydriodic and hydrobromic acids, neutralized, in all probability, by
magnesia, and constituting salts which are decomposable at a low
temperature. He has no doubt that a sufficient supply of bromine
might be procured from our English brine springs, should it ever
happen that a demand for this new substance were to arise.
2. Experiments to determine the difference in the Number of Vibra-
tions made by an invariable Pendulum in the Royal Observatories
of Greenwich and Altona. By Captain Edward Sabine, of the
Royal Artillery, Secretary to the Royal Society. [Read March
25, 1830.]
THE invariable pendulum, No. 1*2, with which experiments recorded
in this paper were made, was vibrated in the Royal Observatory of
Greenwich in July, 1828; in the Royal Observatory at Allona in
September and October of the same year ; and again at the Royal
Observatory at Greenwich in August, 1829. The mean of the
results obtained at Greenwich in July, 1828, and in August, 1829,
gives the rate of this pendulum at Greenwich, to be compared with
its rate obtained at Altona. The details of all these series of obser-
vations are given in a tabulated form.
3. Experiments to ascertain the correction for Variations of Tempera'
ture within the limits of the natural Temperature of this Climate,
of the invariable Pendulum recently employed by British Observers.
By the same Author. [Read March 25, 1830.]
THE correction for temperature which the author deduces as the
general result of his investigation, is 0.44 of a vibration per diem
for each degree of Fahrenheit between 30° and 60°. He considers
this result as entitled to the greater confidence, from the favourable
nature of the circumstances under which the inquiry was conducted ;
since the influence of natural temperature is more permanent and
equable than that of temperatures artificially produced. He consi-
ders it as desirable, however, that means should be devised of
extending experiments on this subject to a wider range of tempera-
tures.
4. On a new Register Pyrometer, for measuring the Expansions of
Solids, and determining the higher degrees of Temperature upon
the common thermometric scale. By J. Frederic Daniell, Esq.
F. R. S. [Read June 17, 1830.]
IN the year 1821, the author published in the Journal of the Royal
Institution, an account of a new pyrometer, and of some determi-
nations of high temperatures, in connection with the scale of the
mercurial thermometer, obtained by its means. The use of the
instrument then described was, however, limited ; and the author
was subsequently led to the invention of a pyrometer of a more
Philosophical Transactions. 339
universal application both to scientific researches, and to various
purposes of art. He introduces the subject by an account of the
attempt of M. Guyton de Morveau, to employ the expansions
of platiria for the admeasurement of high temperatures, and for
connecting the indications of Wedgewood's pyrometer with the
mercurial scale, and verifying its regularity. The experiments of
that philosopher, on the contraction of porcelain in actual compa-
rison with the platina pyrometer, were extended to no higher tem-
perature than the melting point of antimony ; but they are sufficient
to establish the existence of a great error in Wedgewood's original
estimation of his degrees up to that point. This he carries on by
calculation, on the hypothesis of uniform progression of expansion,
up to the melting point of iron ; the construction of his instrument
not admitting of its application to higher temperatures than a red
heat, in which platina becomes soft and ductile.
Mr. Daniell shews, by an examination of M. Guyton's results,
that he has failed in establishing the point he laboured to prove,
namely, the regularity of the contraction of the clay pieces*
The pyrometer of the author consists of two distinct parts, the
one designated the Register; the other the Scale.
The first is a square tube of black lead, eight inches long, cut out
of a common crucible of the material, closed at one end, and having
at the other a portion of about six tenths of an jnch in length, cut
away to the depth of half the diameter of the bore, so as to leave a
shoulder near the end. A bar of any metal, six inches and a half
long, is introduced into the cavity, resting against its solid end, and
a cylindrical piece of porcelain, about one and a half inch long,
which he calls the index, is placed upon the top of the bar, and
projects beyond the open part of the tube, being confined in its
place by a ring or strap of platina passing round it, and also round
the end of the black lead bar, and made sufficiently tight by a small
porcelain wedge inserted between them. When the instrument
thus prepared is subjected to heat, the porcelain index will be
forced up by the expansion of the metallic bar, to a certain dis-
tance, where it will remain when the bar retires from it, on cooling.
The distance it has been moved from its original position, will be
the measure of the difference of expansion of the metallic bar, and
of an equal length of the black lead, in which it is contained. This
cannot be influenced by any permanent contraction which the black
lead may undergo by intense heat ; because any such contraction
will occur at the moment of the greatest expansion of the metal ;
and the index will still mark its point of furthest extension upon
this contracted basis. It remains then to measure accurately the
distance to which the index has been moved, by the application of
the scale, which is a detached instrument constructed of two rules
of brass, joined together at a right angle, the one fitting square
upon two sides of the black lead bar, the other resting on its
shoulder; with these are connected two arms, which, acting on
the principle of proportional compasses, measure the distance of the
340 Analysis of Books.
extremity of the index from the shoulder of the black lead bar. The
spaces comprehended between the points of the shorter legs of the
compasses, are magnified ten times by the longer legs, the angular
motion being measured by a graduated arc furnished with a vernier,
and capable of being easily read oft' to minutes.
The author next enters into a comparison of the results afforded
by this instrument with those of former experimentalists, and
especially with the accurate determination of the expansions of
metals by Messrs. Dulong and Petit, with a view to shew the
degree of confidence to which it is entitled. The close agreement
in the results of a great number of experiments upon metals,
which differ much in their expansions, is highly satisfactory in this
respect. Differences having been found in the expansibility of
different specimens of black lead, it becomes necessary to ascertain
the expansions of each register for itself, by applying to it the heat
of boiling mercury.
The author concludes with an account of some experiments
which he made to determine the fusing points of different metals,
referred to the common thermometric scale. The final results
which he obtained were — for silver, 1873°; copper, 1996°; gold,
2016°; iron, 2786°.
A, remarkable accordance is found between the results with
platina and with iron, metals which differ widely in their expan-
sions ; conformably with the conclusion of MM. Dulong and Petit,
the expansion of iron increases at higher temperatures in a greater
ratio than that of the platina. The discrepancy between the tem-
peratures derived from the observations with his first pyrometer
and the present one he admits to be considerable, but believes they
may be sufficiently accounted for by the differences in the circum-
stances of the experiments, without imputing inaccuracy to either
instrument.
The author next attempted to ascertain the effects of the most
intense heat which it was possible to produce in a furnace, and to
measure the utmost limits of expansion in a platina bar ; but various
circumstances interfered with the success of these experiments,
which afforded, however, many curious results as to changes
of integration in platina by the effects of heat. The paper con-
cludes with some observations on the practical advantages possessed
by the present instrument*.
5. On the Phe?iomena and Laws of Elliptic Polarization, as exhi-
, bited in the Action of Metals upon Light. By David Brewster,
LL.D., RR.S. L. and E. [Read April 22, 1830.]
THE action of metals upon light has always presented a remark-
able, and hitherto inexplicable anomaly in the science of polariza-
tion. Malus, to whom this branch of optics owes its origin, had at
first announced that metals exerted no polarizing influence on
* The register-pyrometer is made by Mr. Newman, 122, Regent Street.
Philosophical Transattions. 341
light ; bnt Dr. Brewster, by employing a different method of obser-
vation, ascertained that the light reflected from metallic surfaces
was modified in such a manner as to exhibit, when transmitted
through thin crystallized plates, the complementary colours of polar-
ized light. He afterwards discovered the curious property possessed
by silver and gold of dividing a polarized ray into complementary
colours by successive reflexions. Mr. Biot, to whom the author
communicated this discovery, pursued the inquiry to which it led,
and arrived at the same conclusions as to the mode in which this
class of phenomena should be explained. Subsequent researches,
however, convinced the author that these generalizations had been
too hastily formed, and the study of Fresnel's curious discoveries
respecting circular polarization enabled him to advance still further
in the inquiry ; and he now presents to the Royal Society, in this
paper, a complete analysis of the singular phenomena exhibited in
the action of metals upon light.
The first section of the paper treats of the action of metals upon
common light. A ray of common light reflected from a metallic
surface, when analysed by a rhomb of calcareous spar, exhibits a
defalcation of light in one of the images, as if a portion of the light
was polarized in the plane of reflexion. This effect will be still
jnore distinctly seen on examining the system of polarized rings
formed round the axes of crystals by means of the light reflected
from metals. If the light had suffered no modification by reflexion,
or if the metal reflected in equal quantities the light polar-
ized in opposite planes, the rings would not be visible at all.
Whereas it is found that they are easily visible in the light reflected
from all metals. They are most distinctly perceived at an incidence
of about 74°, and become more and more faint as the incidence
succeeds or falls short of that angle. They appear best defined
in light reflected from galena, and from metallic lead, and with
least distinctness in light reflected from silver and gold. On ex-
amining the effect of successive reflexion of the same ray by
metallic surfaces, the author found that the quantity of light which
each polarizes in the plane of reflexion increases with every re-
flexion ; and that in several cases the whole incident pencil is com-
pletely polarized.
The action of metals upon polarized light forms the subject of
the second section of this paper, in which he investigates the
changes which polarized light undergoes accordingly as it is re-
flected at different angles of incidence, and in different azimuths of
the plane of primitive polarization. The light experiences in these
cases a physical change of a nature intermediate between that of
completely polarized light, and light wholly unpolarized ; neither
does it possess the same characters as that which has passed
through thin crystallized plates. Its constitution is exceedingly
analogous to light which is circularly polarized ; that is, which
comports itself as if it revolved with a circular motion during its
transmission through particular media. But in the case of circular
342 Analysis of Books.
polarization, the ray has the same properties in all its sides, and
the angles of reflexion at which it is restored to simple polarized
light in different azimuths are all equal, like the radia of a circle
described round the ray. In the case of metallic reflexions, the
new phenomena discovered by Dr. Brewster may be designated by
the term elliptic polarization, because the angles of reflexion at
which this kind of light is restored to polarized light may be repre-
sented by the variable radius of an ellipse. In circular polarization
the restored ray has its plane of polarization always inclined 45°
to the plane of the second system of reflexion. In elliptic polari-
zation the inclination of the plane of the restored pencil is always
less than 45°. In the former case this plane continues by successive
reflexions to oscillate on each side of the plane of reflexion, with a
never varying amplitude + 45° to — 45°. While in the latter case the
same plane oscillates with an amplitude continually diminishing
till it is brought to Zero in the plane of reflexion. In steel the
polarization is highly elliptical, and the amplitude of the oscillations
of the plane of restoration is quickly brought to Zero ; but in
silver, whose polarization approaches nearly to circular, the oscil-
lations diminish very slowly in amplitude. The peculiar character
of elliptic polarization shews itself also in another manner, in the
variable position of the ellipses which regulate its angles of resto-
ration upon steel. In the third section of his paper, the author
treats of the complementary colours produced by successive reflexion
from the polished surfaces of metals.
He concludes by observing, that although we do not understand
the nature of the forces by which metals reflect the two oppositely
polarized pencils, yet we are certain they do not act exactly in the
same manner as the second surfaces of transparent bodies : when
producing total reflexion setting out from a perpendicular incidence,
the least refrangible rays begin to suffer the double reflexion sooner
than the mean ray, and they sooner reach their maximum of elliptic
polarization, thus exhibiting the inversion of the spectrum. The
theory of circular polarization, as given by Fresnel, will, no doubt,
embrace the phenomena of elliptic polarization, and when the nature
of metallic action shall have been more thoroughly examined, we
may expect to be able to trace the phenomena under consideration
to their true source.
6. Researches in Physical Astronomy. By John William Lubbock,
Esq., F. R. S. [Read April 29, 1830.]
THE analytical expressions for the variations of the elliptic constants
given by Laplace, in his Mechanique Celeste, are true only when the
square and higher powers of the disturbing forces are neglected in
the computation : and by proceeding on the supposition that all the
planets move in circular orbits and in the same direction, he has
demonstrated that the eccentricities and inclinations vary within
small limits, and that the stability of the planetary system is always
eventually preserved. But Mr. Lubbock shews, in the present paper,
Philosophical Transactions. 343
that these conditions are not necessary to the stability of a system
of bodies subject to the law of attraction which governs one system ;
and lie gives expressions for the variations of the elliptic constants
which are rigorously true, whatever power of the disturbing force be
retained.
7. On the Error in Standards of Linear Measure, arising from the
Thickness of the Bar on which they are traced. By Captain
Henry Kater, V.P., and Treasurer of the Royal Society. [Read
June 17, 1830.]
WHILE engaged in the adjustment and verification of the copies of
the Imperial Standard Yard destined for the Exchequer, Guildhall,
Dublin, and Edinburgh, the author discovered a source of error
arising from the thickness of the bar, upon the surface of which
measures of linear dimensions are traced. A nctice to that effect
was published in the Philosophical Transactions for 1826; and the
object of the present paper is to give an account of the experiments
the author has since made on this subject, and to describe a scale
which he has had constructed so as almost entirely to obviate the
source of error thus introduced.
From the experiments detailed in the first part of the paper, the
following conclusions are deduced. 1. That in a standard of linear
measure traced upon the surface of a bar, an error arises from the
thickness of the bar when it is placed upon a table, the surface of
which is plane. 2. That this error in bars of the same material
and of unequal thickness lies within certain limits us respects the
thickness of the bar, and depends upon the extension of the surface
of the bar which becomes convex and the compression of the bar which
is concave. 3. That the error to which the same scale is liable from
this cause is directly as the versed sine of the curvature of the sur-
face upon which the scale is placed. 4. That the error very far
exceeds that which would arise from the difference of length between
the arc and its chord under similar circumstances, so much so that
the sum of the errors from this cause in a bar one inch thick with a
versed sine of not one thousandth of an inch is nearly one thousandth
of an inch, whilst double the difference between the chord and the
arc is not one fifty thousandth.
The author devised the following method of trying a surface
supposed to be plane ; namely, by applying to it in different direc-
tions a pianoforte wire, one 100th of an inch in diameter, which
bears a considerable degree of tension without breaking, strung on
a bow six feet long ; a contrivance which, he states, may be applied
to a great variety of useful purposes when a straight edge is re-
quired. He could detect the nature, and, in some degree, the extent
of the irregularities of a surface by tapping with the fingers upon
the wire whilst it was pressed by the weight of the bow upon the
board. When it yielded no sound, the wire was, of course, in eon-
tact with the surface, which was in that case either convex or plane.
"When the wire yielded a sound the surface was concave ; and some
344 Analysis of Books.
idea might be formed of the extent by the acuteness or gravity of the
sound produced, the edges of the concavity serving- as bridges
which limited the length of the string. So delicate is this test, that
a concavity can be detected by this method, when the interval be-
tween the wire and the surface under examination is imperceptible
to the eye.
The error in question, resulting from the extension and compres-
sion of the surfaces of the bar dependant upon its curvature is
obviated in the following manner: — The neutral surface which
suffers neither extension nor compression is shewn by the author to
be at about one- third of the thickness of the bar from the surface
which becomes convex. When the object is to have two points only
on the bar, by cutting away one-half of the thickness of the bar at
its ends, and placing the points upon the new surfaces, the error
is reduced to the least possible quantity. But when a scale of inches
is required, the nearest approximation to correct measurement is
obtained by diminishing, as much as possible, the thickness of the
bar. and by providing another bar on which it is to be supported,
and on which it is allowed to slide freely in a dovetailed groove
formed by two side plates of similar thickness, screwed to the sur-
face of the bar, and to which it is to be fixed at its middle point by
a single screw passing through it.
8. On the Illumination of Light-houses. By Lieut. Thomas Drum-
mond, of the Royal Engineers.
THE author, after briefly describing the different methods at present
employed for illuminating light-houses, proceeds to detail what he
considers an improvement upon those now in use. This consists in
substituting for the Argand burners a small ball of lime, ignited by
the combustion of oxygen and hydrogen.
From this small ball, only three-eighths of an inch in diameter, so
brilliant a light is emitted, that it equals in quantity about thirteen
Argand lamps, or 120 wax candles; while, in intensity or intrinsic
brightness, it cannot be less than 260 times that of an Argand lamp.
These remarkable results are deduced from a series of experiments
made lately at the Trinity-house ; and, having been repeated with
every precaution, and by different individuals, there seems no reason
to doubt their accuracy. In the best of our revolving lights, such
as that of Beachy Head, there are no less than thirty reflectors, ten on
each side. If, then, a single reflector, illuminated by a lime ball, be
substituted for each of these ten, the effect of the three would be
twenty-six times greater than that of the thirty. On account of the
smaller divergence of the former it would be necessary to double
their number, placing them in a hexagon instead of a triangle. In
this case the expense is estimated at nearly the same. This method
was tried lately at Purfleet in a temporary light-house, erected for
the purpose of experiments by the corporation of the Trinity-house,
and its superiority over all the other lights with which it was con-
trasted was fully ascertained and acknowledged.
Philosophical Transactions. 345
On the evening of the 25th of May, when there was no moon-
light, and the night dark, with occasional showers, the appearance
of the light viewed from Blackwall, a distance of ten miles, was
described as being very splendid. Distinct shadows were discern-
ible, even on a dark brick wall, though no trace of such shadows
could be perceived when the other lights, consisting of seven re-
flectors with Argand lamps, and the French lens, were directed on
the same spot. Another striking and beautiful effect peculiar to
this light was discernible when the reflector was turned, so as to be
itself invisible to the spectator. A long stream of rays was seen
issuing from the spot where the light was known to be placed, and
illuminating the horizon to a great distance. As the reflector re-
volved, this immense luminous cone swept the horizon, and indi-
cated the approach of the light long before it could itself be seen
from the position of the reflector.
These singular effects must not, however, be understood as con-
stant accompaniments of this light, for on a moonlight night, or
when the weather is very hazy, they cease to appear.
9. On the Electro- Magnetic properties of Metalliferous Veins in the
Mines of Cornwall. By Robert Ware Fox. [Read June 10,
1830.]
THE author having been led, from theory, to entertain the belief that
a connection existed between electric action in the interior of the
earth, and the arrangement of metalliferous veins, and also the pro-
gressive increase of temperature in the strata of the earth as we
descen&from the surface, proceeded to the verification of this opinion
by experiment. His first trial wasfcunsuccessful, but in the second,
he obtained decisive evidence of considerable electrical action in
the mine of Huel Servel, in Cornwall. His apparatus consisted of
small plates of sheet copper, nailed, or else wedged closely, against
the wooden props stretched across the galleries. Between two
of these plates of different stations, a communication was made,
by means of copper wire, one twentieth of an inch in diameter, which
included a galvanometer in its circuit. In some instances three
hundred fathoms of copper wire was employed.
The intensity of the electric currents was found to differ consi-
derably in different places ; it was generally greater in proportion
to the greater abundance of copper ore in the veins ; and in some
degree also to the depth of the station. Hence the discovery of the
author seems likely to be of practical utility to the miner in disco-
vering the relative quantity of ore in veins, and the directions in
which it most abounds. The electricity thus perpetually in action
in mines, does not appear to be influenced by the presence of the
workmen and candles, or even by the explosion of gunpowder in
blasting.
The author's experiments enable him to give a table of the rela-
tive powers of conducting galvanic electricity possessed by various
metalliferous minerals, This power, he remarks, appears to bear no
346 . Analysis of Books.
obvious relation to any of the electrical or other physical properties
of the metals themselves, when in a proper state, or to the propor-
tions in which they exist in combination. He proceeds to point out
various facts relative to the position of veins and the arrangement
of their contents, which he thinks are irreconcilable with any of
the hypotheses that have been devised to explain their origin.
He observes that ores which conduct electricity have generally
some conducting substances interposed in the veins between them
and the surface ; a structure that appears to bear a striking analogy
to the ordinary galvanic combinations. He is of opinion that the
intensities both of heat and of electricity, and consequently of mag-
netism, increase in proportion to the depths of the strata under the
surface of the earth ; that they have an intimate connection with
one another ; and that the discovery of electrical currents in
various, and frequently opposite directions, in different, parts of the
same mine, may, perhaps, hereafter afford a clue to explain the de-
clination and variation of the magnetic needle.
10. Sequel to a Paper on the tendency to Calculous Diseases, and oti
the Concretions to which such Diseases give rise. By John
Yelloly, M.D., F.R.S. [Read June 17, 1830.]
THE author, in a paper published in the last volume of the Philo-
sophical Transactions, gave the analysis of 328 calculi contained in
the collection of the Norfolk and Norwich hospital ; and has been
since enabled to complete the analysis of the 335 remaining speci-
mens which have now been divided. The results of the analysis
are given in a tabular form, exhibiting in the order of their occur-
rence from the centre the coifsecutive deposits of the different
materials of which the calculi are composed, according to the most
prominent character of each material. The most remarkable cir-
cumstance brought to light in the course of this investigation, is the
discovery of the presence of silex in one specimen composed prin-
cipally of oxalate of lime, and weighing about five grains. The
particles of silex were very minute, and were imbedded in, and dif-
fused through the oxalate of lirne. Three examples of a similar
occurrence are quoted by the author.
The paper concludes with a few remarks on the statistical con-
clusions stated in his former communication. He thinks there is
reason to believe that the average number of calculous disorders
in Scotland has been much under-rated ; on the other hand, the
proneness to those complaints is very small in Ireland. A much
larger proportion of calculous cases occurs in towns than in the
country.
(317 )
The Life of Sir Humphry Davy, Bart., LL,D.t laic President of
the Royal Society, fyc. $c. #c. By John Ayrton Paris, M.D.,
F.R.S., &c. &c. 4to. London, 1831.
history of science offers to our notice several remarkable
epochs at which the human mind has seemed to receive an ex-
traordinary impulse, when a train of circumstances has led to the
development of some supereminent genius, who, soaring beyond
the ken of his fellow men, by his happy discoveries in the regions
of truth and nature, has traced out new roads to knowledge, tending
to advance the progress of civilization whole ages in a few short
years. Such were Bacon, Galileo, Kepler, Newton, Franklin, and
Watt. A similar period has just elapsed in the first thirty years
of the nineteenth century, and such a gifted being was Davy.
Dr. Paris has justly observed that —
'The extent of our obligations to a philosopher cannot be appreciated
until time shall have shown the various important purposes to which his
discoveries may administer. The names of Mayow and Hales might
have been lost in the stream of discovery, had not the results of Priestley
and Lavoisier shown the value and importance of their statical experi-
ments on the chemical relations of air to other substances. The disco-
veries of Dr. Black on the subject of latent heat could never have
obtained that celebrity they now enjoy, had not Mr. Watt availed nim-
self of their application for the improvement of the steam-engine ; and
the views of Sir H. Davy respecting the true nature of chlorine become
daily more important from the discovery of new elements of an analo-
gous nature. In future ages, the metals of the alkalies and earths may
admit of applications, and open new avenues of knowledge, of which at
present we can form no idea ; but it is obvious that, in the page of
history, his name will gather fame in proportion as such discoveries
unfold themselves.1
Humphry Davy was born at Penzance in Cornwall, on the 17th
of December, 1778. His ancestors had long possessed a small
estate at Varfell, in the Mounts Bay, to which his father, who had
been apprenticed to a carver in wood, and exercised his art with
considerable skill, at length succeeded. He was first placed at a
preparatory school kept by a Mr. Bushell, who was so struck with
the progress he made, that he urged his father to remove him to a
superior school, and Dr. Paris has shown that in his early fondness
for fiction, and in the power of creating imagery for the gratification
of his fancy, Davy greatly resembled Sir Walter Scott. At an
early age he was placed at the Grammar School of Penzance, under
the Rev. J. C. Coryton, boarding with Mr. Tonkin, an eminent
surgeon of that town. While at this school he wrote verses and
ballads, and frequently amused his young companions with fire-
works and thunder-powders of his own making, and other puerile
exhibitions of the same class, which manifested his early passion
for experiment. He was extremely fond of fishing, and of shooting-
when old enough to carry a gun, and made this last amusement
subservient to his love of knowledge by forming a collection of rare
348 Analysis of Books.
birds, which he stuffed with no ordinary skill. From Penzance he
went to Truro, in 1793, and finished his education under Dr.
Cardew, who did not discern in him the faculties by which he was
afterwards distinguished. ' I discovered,' says Dr. Cardew, * his
taste for poetry, which I did not omit to encourage.' Davy's own
opinion of the influence of his early school career is interesting. —
* After all,' he says, * the way in which we are taught Latin and
Greek does not much influence the important structure of our
minds. I consider it fortunate that I was left much to myself as a
child, and put upon no particular plan of study, and that I enjoyed
much idleness at Mr. Coryton's school. I perhaps owe to these
circumstances the little talents I have, and their peculiar applica-
tion. What I am I have made myself. I say this without vanity,
and in pure simplicity of heart.' His father died in 1794, and his
mother (who had taken up her residence at Penzance, and entered
into business as a milliner) apprenticed him to Mr. Borlace, a sur-
geon and apothecary, who afterwards practised as a physician in
that town. Davy seems not to have had much predilection for
this profession, and though he had long been engrossed with
experimental philosophy, he now first manifested his decided turn
for chemistry, the study of which he commenced with all the ardour
of his temperament. He still continued to write verses, and several
of his minor productions were printed in the Annual Anthology,
edited by Southey and James Tobin, in 1799. Some of these Dr.
Paris has reprinted. We know not whether it was upon the evi-
dence of these effusions, or from the general character of Davy's
writings, that it has been said, * If Davy had not been the first
chemist, he would have been the first poet of his age ;' but Dr.
Paris inquires, ' Where is the modern Esau who would exchange
his Bakerian Lecture for a poem, though it should equal in design
and execution the Paradise Lost ? '
Davy's first original experiments in chemistry are said to have
been made to ascertain the quality of the air contained in the
bladders of sea-weed, in order to obtain results in support of a
favourite theory of light ; and to ascertain whether sea-vegetables
might not be the preservers of the equilibrium of the atmosphere of
the ocean ; and he came to the conclusion that the marine crypto-
gamia were capable of decomposing water when assisted by the
attraction of light for oxygen. His instruments of research were of
the rudest description, made by himself out of the motley materials
which chance threw in his way. Dr. Paris suggests, that from hence
we may date his wonderful tact of manipulation, and that ability in
suggesting expedients, arid contriving apparatus, to meet and sur-
mount difficulties 1n the unbeaten tracts of science, for which he
was afterwards distinguished. At seventeen he had formed and
promulgated an opinion adverse to the general belief in the exist-
ence of caloric, or the materiality of heat.
' No sooner,' says Dr. Paris, « had he formed his opinion, than his
eagle spirit urged him to put it to the test, Having procured a piece of
Life of Sir Humphry Davy. 349
clock-work, so contrived as to be set to work in an exhausted receiver,
he added two horizontal plates of brass ; the upper one, carrying a smah1
metallic cup, to be filled with ice, revolved in contact with the lower one.
The whole machine, resting on a plate of ice, was covered by a glass
receiver, and the air was exhausted by a syringe; [ingeniously modified
for the purpose from an old glyster apparatus ;] for as yet he had no air-
pump, and, what is still more worthy of notice, had never seen one ! The
machine was now set in motion, when the ice in the small cup began to
melt; whence he inferred that this effect could alone proceed from
vibratory motion, since the whole apparatus was insulated from all acces-
sion of material heat, by the frozen mass below, and by the vacuum
around it.'
The experiment was afterwards repeated under more favourable
circumstances, and the icsults published in an Essay on Heat,
Light, and the Combinations of Light; and it has been justly
observed by Mr. Gilbert, that though it does not at nil decide the
important matter in dispute, but few young men remote from the
society of persons conversant with science would be capable of
devising anything so ingenious.
The introduction of Davy to Mr. Davies Gilbert about this time
was perhaps one of the most influential circumstances in his life.
Mr. Gilbert's attention was attracted to him, as he was carelessly
swinging on the hatch or half-gate of Mr. Borlace's house, by the
humorous contortions into which he threw his features ; and being
told he was fond of making chemical experiments, he spoke to him;
soon discovered ample evidence of his singular genius, and after
several interviews, offered him the use of his library, or any other
assistance he might require in the pursuit of his studies, and gave
him an invitation to his house at Tredrea, of which Davy frequently
availed himself. The tumultuous delight which he expressed on
seeing', for the first time, a quantity of chemical apparatus, and an
air-pump, is described by Mr. Gilbert as surpassing all description.
Soon after, Davy's acquaintance commenced with Mr. Gregory
Watt, who came to Penzance on account of his health, and lodged
in the house of his mother.
' Davy sought to ingratiate himself with Mr. Watt by metaphysical
discussions ; but instead of admiration, he excited the disgust of his
hearer. It was by mere accident that an allusion was made to che-
mistry, when Davy flippantly observed, that he would undertake to demo-
lish the French theory in half an hour. He had touched the chord ; the
interest of Mr. Watt was excited ; he conversed with Davy on his che-
mical pursuits, and was at once astonished and delighted at his sagacity
— the barrier of ice was broken, and they became attached friends.'
Mr. Josiah and Mr. Thomas Wedgwood also spent a winter at
Penzance ; and Dr. Paris says he has reason to believe their friend-
ship was of substantial benefit to Davy.
Upon the establishment of the * Pneumatic Institution ' at
Bristol, for the purpose of investigating the medical power of gases,
Dr. Beddoes required an assistant, and Mr. Gilbert recommended
Davy. Dr. Beddoes was acquainted with his experiments upon
VOL, I. Tea, 1831. 2 A
350 Analysis of Books.
light and heat, which had produced a favourable impression, and
after some little negotiation, he was engaged ; his mother yielded
to his wishes ; and Mr. Borlace generously surrendered his inden-
ture, indorsing upon it, that he freely gave it up * on account of the
singularly promising talents which Mr. Davy had displayed.' He,
however, so offended his old friend, Mr. Tonkin, by this measure,
that he revoked the legacy of his house, which he had previously
bequeathed him, in contemplation of fixing him in his native
town as a surgeon. Davy quitted Penzance for Bristol in high
spirits, in October, 1798, before he had attained his twentieth year.
His position was now extremely favourable to the development of
his genius. He was constantly engaged in the prosecution of new
experiments, in the conception of which he was greatly aided by
Dr. Beddoes, and occasionally assisted by Mr. Clayfield, to whom
he was indebted for the invention of a mercurial air-holder, by
which he was enabled to collect, measure, and examine the various
gases. He enjoyed at Bristol the advantage of intellectual society ;
among others with whom he was intimate, were Mr. Edgeworth,
and James Tobin, the author of the Honey Moon. The present
Lord Durham and his brother were then also resident in the house
of Dr. Beddoes. With some of these eminent persons Davy con-
tracted permanent friendships. Dr. Paris says, ' there was more
than one avenue to his heart ; and the philosopher, the poet, the
physician, the philanthropist, and the sportsman, found each, upon
different terms, a more or less ready access to its recesses ; but the
fisherman instantly caught his affections.' ' To be a fly-fisher was,
in his opinion, to possess the capabilities of intellectual distinction,
though circumstances might not have conspired to call them into
action.' It has been asserted by those who knew him through life,
* that his extraordinary talents never at any period excited greater
astonishment than during his residence at Bristol.'
At the commencement of 1799, Dr. Beddoes published a work
under the title of ' Contributions to Physical and Medical Know-
ledge, principally from the West of England ;' nearly one-half of
the volume consists of essays by Davy : ' On Heat, Light, and the
Combinations of Light ;' 'On Phos-oxygen, or Oxygen and its
Combinations ;' and * On the Theory of Respiration.'
' In his chapter on Light and its Combinations,' says his biographer,
* he indulges in speculations of the wildest nature, although it must be
confessed that he has infused an interest into them which might be
almost called dramatic. His first essay commences with an experiment
in order to show that light is not, as Lavoisier supposed, a modification,
or an effect of heat ; but matter of a peculiar kind, sui generis, which,
when moving through space, or in a state of projection, is capable of
becoming the source of a numerous class of our sensations. With
regard to caloric his opinion was, that it is not, like light, material ; and
he maintains the proposition by the same method of reasoning as that by
which he attempts to establish the materiality of light, and which mathe-
maticians have termed the reductio ad absurdum.'
Life of Sir Humphry Davy. 351
Dr. Paris has given an outline of these extraordinary essays, to
which we must refer the reader.
The letters of Davy at this period to his friend, Mr. Davies
Gilbert, give an interesting- account of his experimental pursuits.
The accidental observation, that two pieces of bonnet cane rubbed
together produced a faint light, led him to examine into the cause.
On removing the epidermis, he found that no light was produced ;
and subjecting the epidermis to chemical analysis, it proved to have
all the properties of silex: the similar appearance of the epidermis
of reeds, corn-straw, and grasses, induced him to suppose that they
likewise contained silex ; by burning them carefully and analysing
their ashes, he found they contained it in larger proportions than
the canes, and that the straws and grasses contain sufficient potash
to form glass with their flint. He says, * A very pretty experiment
may be made on these plants. If you take a straw of wheat,
barley, or hay, and burn it, beginning at the top, and heating the
ashes with the blue flame, you will obtain a perfect globule of hard
glass fit for microscopic experiments.' It was at this period that
he was led by the nature of his engagements at Bristol to com-
mence his inquiries into the nature of nitrous oxide, and the results
enabled him to give to the world the first satisfactory account of
the combinations of oxygen and nitrogen. These he published in a
distinct volume, in the year 1800, under the title of * Researches,
Chemical and Philosophical, chiefly concerning Nitrous Oxide and
its Respiration/
' The close philosophical reasoning, ' (says Dr. Paris,) — ' the patient
and penetrating industry,— the candid submission to every intimation of
experiment, — and the accuracy of manipulation, so remarkably displayed
throughout this work, — have rarely been equalled, and perhaps never
surpassed. What shall we say of that spirit, which led him to inspire
nitrous gas at the hazard of filling his lungs with the vapour of aqua
fortis ! or what of that intrepid coolness, which enabled him to breathe
a deadly gas [carburetted hydrogen], and to watch the advances of its
chilling power in the ebbing pulsations at the wrist ? '
Dr. Paris gives an amusing account of the effects which the
breathing of nitrous oxide produced on several scientific and lite-
rary friends of Davy, and thinks that, though the fact is established,
that the gas possesses an intoxicating quality, the enthusiasm of
persons submitting to its operation has imparted a character of
extravagance to its effects not quite consistent with truth. Davy
had nearly fallen a victim to his temerity, in breathing three quarts
of hydro-carbonate, mingled with nearly two quarts of atmospheric
uir. This daring experiment, Dr. Paris thinks, if the precautions it
suggests be properly attended to, may become the means of pre-
serving human life, and is also valuable, as affording support to
physiological views, with which its author was probably not ac-
quainted. It is important, inasmuch as it proves that, in cases of
asphyxia, or suspended animation, there exists a period of danger
2 A 2
352 Analysis of Books.
after the respiration has been restored, and the circulation re-esta
blished, at which death may take place, when we are the least pre-
pared to expect it. In the ' Researches ' no allusion is made to the
theory or nomenclature of ' Essays on Heat and Light.' Soon after
their publication, he says, in a communication to Mr. Nicholson,
* I beg to be considered as a sceptic with respect to my own parti-
cular theory of the combinations of light, and shall in future use the
common nomenclature.' ' It is remarkable that in several passages
of the " Researches " he advocates the theory of the atmospheric
air being* a chemical compound of oxygen and nitrogen ; whereas
in later years, he was among the first to insist upon its being simply
a mechanical mixture of these gases.'
His health having suffered from close application and the delete-
rious nature of his experiments, he retired to his native place, where
he soon recovered ; and we find him in the vigorous pursuit of his
experiments in October, 1800, when he first announces to his friend
Mr. Gilbert, ' those new facts in voltaic electricity/ which may be
said to have paved the way to his grand discoveries in that branch of
science. He says —
* In pursuing experiments on galvanism during the last two months, I
have met with unexpected and unhoped-for success. Some of the new
facts on this subject promise to afford instruments capable of destroying
the mysterious veil which nature has thrown over the operations and pro-
perties of etherial fluids. Galvanism I have found to be a process purely
chemical, and to depend wholly on the oxidation of metallic surfaces,
having different degrees of electric conducting power,' &c.
His* Researches' excited general admiration in the philosophic
world, which was increased by the circumstance of a work so replete
with ingenious novelty and chemical discovery proceeding from the
pen of so young a man ; and the publication may be considered as
the immediate cause of an event which proved in its result not less
important in its influence on his future fortunes than it has been on
the interests of science. The Royal Institution had been then re-
cently established for the advancement of science and the useful arts,
in the establishment and direction of which Count Rumford took an
active part. The fame of the young philosopher naturally attracted
his attraction. Mr. Underwood, a gentleman attached to science
and devoted to the interests of the Institution, was among the first
to urge the expediency of inviting him to London as a public lec-
turer, and the Count, having received full powers from the Managers
to negotiate on the subject, communicated with Mr. Underwood,
who referred him to Mr. James Thompson, Davy's intimate friend,
who wrote to Davy, with an earnest recommendation that he should
come to town arid conclude the arrangement. Davy answered the
letter in person, was introduced to the Managers, received in the
most flattering manner, and engaged as Assistant Lecturer in Che-
mistry, Director of the Laboratory, and Assistant Editor of the Jour-
nals of the Institution. He arrived at the Institution, and entered
Life of Sir Humphry Davy. 353
upon his functions on the llth of March, 1801. The letter in which
he announces the circumstance to Mr. Gilbert, contains the following
passage:-—
' Thus I am quickly to be transferred to London, whilst my sphere of
action is considerably enlarged, and as much power as I could reasonably
expect, or even wish for at my time of life, secured to me without the
obligation of labouring at a profession. The Royal Institution will, I
hope, be of some utility to society. It has undoubtedly the capability of
becoming a great instrument of moral and intellectual improvement. Its
funds are very great. It has attached to it the feelings of a great number
of people of fashion and property, and consequently may be the means of
employing, to useful purposes, money which would otherwise be squan-
dered in luxury, and in the production of unnecessary labour. As for
myself, I shall become attached to it full of hope, with the resolution of
employing all my feeble powers towards promoting its true interests.'
It is said that the first impression produced on Count Rumford
by Davy's personal appearance was highly unfavourable, but his
first lecture removed every prejudice of this kind ; they soon became
friends, entertaining for each other the highest regard. He so greatly
satisfied the Managers of the Institution, that on the 1st of June
they passed a resolution —
4 That Mr. H.Davy, Director of the Chemical Laboratory, and Assist-
ant Lecturer in Chemistry, has, since he has been employed at the Insti-
tution, given satisfactory proofs of his talents as a lecturer. Resolved —
That he be appointed, and in future denominated, Lecturer in Chemistry
at the Royal Institution, instead of continuing to occupy the place of
Assistant Lecturer, which he has hitherto filled.'
Dr. Garnett had been Professor of Natural Philosophy in the
Royal Institution from its first establishment, and Davy had lived
on terms of great intimacy with that amiable man, whose health had
been long declining. He resigned his professorship on this account
in July of this year, and was succeeded by the late Dr. Young, who
was engaged as Professor of Natural Philosophy, Editor of the
Journals, and Superintendent of the Establishment. With this
eminent philosopher Davy associated with less ease and freedom.
In November of this year he thus notifies another galvanic disco-
very : —
' I yesterday ascertained rather an important fact, namely, that a gal-
vanic battery may be constructed without any metallic substance ! By
means of ten pieces of well-burnt charcoal, nitrous acid, and wafer
arranged alternately in wine-glasses, I produced all the effects usually
obtained from zinc, silver, and water.'
His introductory lecture, delivered on the 21st of January, 1802,
was received by a crowded audience with universal applause. It
contains a masterly view of the benefits to be derived from the various
branches of science ; and in referring to the great agency of chemistry
in the improvement of society, he makes the following almost pro-
phetic remarks : —
' Unless any great physical changes should take place upon the globe,
the permanency of the arts and sciences is rendered certain, in conse-
quence of the diffusion of knowledge by means of the invention of print-
354 Analysis of Books.
ing ; and by which those words, which are the immutable instruments of
thought, are become the constant and widely-diffused nourishment of the
mind, and the preservers of its health and energy.' ' Individuals, influ-
enced by interested motives, or false views, may check for a time the pro-
gress of knowledge, — moral causes may produce a momentary slumber of
the public spirit, — the adoption of wild and dangerous theories by ambi-
tious or deluded men may throw a temporary opprobrium on literature ;
but the influence of true philosophy will never be despised, the germs of
improvement are sown in minds even where they are not perceived ; and,
sooner or later, the spring-time of their growth must arrive. In reason-
ing concerning the future hopes of the human species, we may look for-
ward with confidence to a state of society, in which the different orders
and classes of men will contribute more effectually to the support of
each other than they have hitherto done. This state indeed seems to be
approaching fast ; for, in consequence of the multiplication of the means
of instruction, the man of science and the manufacturer are daily becom-
ing more assimilated to each other. The artist, who formerly affected to
despise scientific principles, because he was incapable of perceiving the
advantages of them, is now so far enlightened as to favour the adoption of
new processes in his art, whenever they are evidently connected with a
diminution of labour ; and the increase of projectors, even to too great an
extent, demonstrates the enthusiasm of the public mind in its search after
improvement.'
This lecture was printed^ at the request of a considerable portion
of the Society.
'The sensation created by this first course of lectures at the Institution,
and the enthusiastic admiration which they obtained,' Mr. Purkiss says,
* is at this period scarcely to be imagined — compliments, invitations, and
presents were showered upon him in abundance from all quarters ; his
society was courted by all, and all appeared proud of his acquaintance.'
' It is admitted/ says his biographer, ' that his vanity was excited, and
his ambition raised, by such extraordinary demonstrations of devotion ;
that the bloom of his simplicity was dulled by the breath of adulation, and
that losing much of the native frankness which constituted the great
charm of his character, he unfortunately assumed the garb and airs of a
man of fashion ; let us not wonder if, under such circumstances, the inap-
propriate robe should not always have fallen in graceful draperies.1 It has
been also urged, ' that the style of his lectures was far too florid and ima-
ginative for communicating the plain lessons of truth ; that he described
objects of natural history by inappropriate imagery, and that violent con-
ceits frequently usurped the place of philosophical definitions.'
Dr. Paris has well defended him from this latter censure, by remind-
ing us of the class of persons to whom his lectures were addressed ;
and the writer of this abstract, then very young-, well remembers the
effective and impressive manner in which he led away his hearers
and took their prisoned senses captive. Nothing can be more true
than the remark, that ' the style which cannot be tolerated in a phi-
losophical essay may, under peculiar circumstances, be not only
admissible, but even expedient in a popular lecture/ In addition
to these morning lectures he gave, at the same, time, an evening
course on galvanic phenomena. In May, 1802, he was appointed
Professor of Chemistry to the Royal Institution. Davy seems him-
self to have been sensible that his audience required something more
Life of Sir Humphry Davy. 355
than mere science to fix their attention. In giving his early friend,
Mr. Gilbert, an account of his successful exertions, he says — * In
lectures, the effect produced upon the mind is generally transitory ;
for the most part they amuse rather than instruct, and stimulate to
inquiry rather than convey information.' In this letter he mentions
the powerful galvanic battery which he had caused to be constructed
for the laboratory of the Institution, consisting of 500 plates of five
inches in diameter, and 40 plates of a foot in diameter, and that by
means of it he had been enabled to burn inflammable substances,
to fuse platina wire, &c., and to boil and decompound oil and water ;
and that he was then engaged in examining its agencies upon sub-
stances which had not as yet been decomposed. * The elegance with
which his experiments in the theatre were conducted was strangely
contrasted to the slovenly style of his manipulations in the laboratory.
So rapid were his movements, that he would carry on several un-
connected experiments at one time, and while it was imagined that
he was merely preparing for an experiment, he was actually obtaining
the results/ 4 With Davy,' adds Dr. Paris, * rapidity was power.'
Whatever diversity of opinion may have been entertained of Davy's
style as a lecturer, his philosophical memoirs are so remarkable for
clearness, simplicity of language, and freedom from technical expres-
sions, that they have been proposed as models for all future chemists ;
and Mr. Brande, in a lecture delivered last year before the members
of the Royal Institution, forcibly contrasted his style with that of
another eminent foreign chemist on this ground. Davy himself, in
his * ' Last Days of a Philosopher,'' has the following remarkable pre-
cept, which he supported by his example : " In detailing the results
of experiments, and in giving them to the world, the chemical phi-
losopher should adopt the simplest style and manner; he will avoid
all ornaments as something injurious to the subject ; and should
bear in mind the saying of James I., — that the tropes and meta-
phors of the speaker were like the brilliant wild flowers in a field of
corn, very pretty, but which very much hurt the corn.'"
The first series of the Journal of the Royal Institution was pub-
lished in monthly numbers, and the price was fixed at one shilling,
in the hope that it might be more generally diffused. It contained
abridged accounts of what was going on in the scientific world,
abroad and at home, and several very interesting original papers by
Dr. Young and by Davy, who appears to have acted as joint
editor. His original communications were — * An Account of a new
Eudiometer ;' ' Several Papers on Galvanic Phenomena ;' * On the
Gallic Acid;' and * On the Processes of Tanning ;; * An Account of
a Method of Copying Paintings upon Glass, and making Profiles by
the agency of Light upon Nitrate of Silver,' invented by Mr. T.
Wedgwood, with observations by Davy ; * On the Collision of Flint
and Steel in vacuo ;' and some * Observations upon the Motions of
small Pieces of Acetate of Potash during their solution upon the
surface of Water/ to which the late interesting observations of Mr,
Brown is calculated to excite attention.
350 Analysis of Books.
Davy's first communication to the Royal Society was * An Ac-
count of some Galvanic Combinations, formed by an Arrangement
of Single Metallic Plates and Fluids, analogous to the Galvanic Appa-
ratus of M. Volta.' It was read in April, 1803, and in November
of that year he was elected a fellow of that Society. He had been
previously elected an honorary member of the Dublin Society.
Shortly after his appointment to the Royal Institution, he had
delivered a series of lectures on the art of tanning ; and having, by
a scientific examination of the subject, added many important facts,
he now embodied them in a Memoir, which was published in the
Philosophical Transactions for 1803, entitled, * An Account of some
Experiments and Observations on the Constituent Parts of certain
Astringent Vegetables, and on their Operation in Tanning ;' of which
Dr. Paris has given an outline, and observes that ' it forms at this
day the guide of the tanner ; and those who previously carried on
the process by a routine of operations of which they knew not the
reasons, are now capable of modifying it without risk of spoiling the
result.' In May, 1803, he gave a course of six lectures on Agricul-
tural Chemistry, before the members of the Board of Agriculture,
and was appointed chemical professor to that Board. This brought
him into contact with the most eminent agriculturists and capitalists
of the day, with many of whom he formed friendships which lasted
through life. These discourses were published in the year 1813.
His biographer may well say —
' We can scarcely picture to ourselves a being upon whom fortune ever
showered more favours than upon Davy, during this golden period of his
career. Independent in an honourable competence, the product of his
genius and industry — resident in the centre of all scientific information
and intelligence, every avenue of knowledge and every mode of observation
open to his unwearied intellect — he must have experienced a satisfaction
which few philosophers have ever before felt — the power of pursuing
experimental research to any extent, and of commanding the immediate
possession of all the means it might require, without the least regard
either to cost or labour. What a contrast does this picture afford to that
which has been too faithfully represented as the more usual fate of the
philosopher and man of letters, and which exhibits little more than the
unavailing struggles of genius against penury! ... Not the least
extraordinary point in the character of this great man was the facility
with which he could cast aside the cares of study, and enter into the
trifling amusements of society. In the morning, he was the sage inter-
preter of Nature's laws ; in the evening, he sparkled in the galaxy of
fashion. When not otherwise engaged, his custom was to play at billiards,
frequent the theatre, or read the last new novel.'
Very shortly after Davy's arrival in London, he formed an inti-
mate friendship with Mr. (afterwards Sir Thomas) Bernarq1, who
allotted him a plot of ground, near his villa at Roehampton, for the
purpose of making experiments in agricultural chemistry. Dr.
Paris passes a well-deserved eulogy upon this most excellent person,
whose ' life was one continued scheme of active benevolence ;* and
he merits a particular notice in these Memoirs, as being one of the
principal founders and patrons of the Royal Institution. The pri-
mary object of the founders was the formation of an institution which
Life of Sir Humphry Davy. 357
might teach the application of science to the advancement of the
arts of life, advance the taste, and science of the country, and improve
the means of industry and domestic comfort among the poor. These
benevolent designs were to be promoted by committees for the pur-
pose, having for their object the advancement, by scientific investi-
gation, of the arts of life, on which the subsistence of all, and the
comfort of the great majority of mankind, absolutely depend. ' At
this early period of its history,' says Dr. Paris, * the Royal Institution
presented a scene of the most animated bustle and exhilarating acti-
vity. It was " like a busy ant-hill in a calm sunshine."'
At the commencement of 1805, Davy enriched the cabinets of the
Institution by a present of minerals, which were reported to be of the
value of 100 guineas ; and he was soon after, in addition to his
professorship, appointed director of the laboratory ; by which ap-
pointment, his annual income from the Institution was raised to four
hundred guineas. At this period he delivered a series of lectures on
Geology, and produced his paper, published in the Philosophical
Transactions, ' Analytical Experiments on a Mineral Production from
Derbyshire (Wavellite), consisting principally of Alumina and Water;'
and soon after he communicated to the same body a paper * On the
Method of analyzing Stones containing a fixed Alkali, by means of
the Boracic Acid/ which is said to have much advanced the art of
mineral analysis. On the death of Dr. Gray, Davy was elected secre-
tary of the Royal Society, at an extraordinary meeting on the 22d
Jan. 1807, being at the same time elected a member of the council.
In Chapter VI. of his work, Dr. Paris enters upon that brilliant
period in the life of Davy, ' at which he effected those grand disco-
veries in science, embracing the development of the laws of voltaic
electricity, which will transmit his name to posterity ;' prefixed we
have a brief view of the history of galvanism, or voltaic electricity,
divided into six grand epochs. Davy, in his Bakerian lecture of
1806, remarks —
' That the true origin of all that has been done in this department of phi-
losophy was the accidental discovery, by Nicholson and Carlisle, of the
decomposition of water by the pile of Volta, in April, 1800, which was
immediately followed by that of the decomposition of certain metallic
solutions, and by the observation of the separation of an alkali on the
negative plates of the apparatus. Mr. Cruikshank, in pursuing these
experiments, obtained many new and important results, — such as the
decomposition of Ihe muriates of magnesia, soda, and ammonia; and
also observed the fact that the alkalitie matter always appeared at the
negative, and acid matter at the positive pole/
' In September, 1800, Davy published his first paper on the subject of
galvanic electricity, in Nicholson's Journal, which was followed by six
others, in which he so far extended the original experiment of Nicholson
and Carlisle, as to show that oxygen and hydrogen might be evolved
from separate portions of water, though vegetable and even animal sub-
stances intervened ; and conceiving that all decompositions might be polar,
he electrised different compounds at the different extremities, and found
that sulphur and metallic bodies appeared at the negative pole, and oxy-
gen and azote at the positive pole, though the bodies furnishing them
were separated from each other. Here was. the dawn of the electro-
358 Analysis of fioolcs.
chemical theory. . . The Bakerian Lecture, read before the Royal
Society in November, 1806, unfolded the mysteries of voltaic action ; and,
as far as theory goes, may be almost said to have perfected our knowledge
of the chemical agencies of the pile.'
Of this celebrated paper, Dr. Paris has given an analysis, to
which we must refer the reader ; it embraces the discovery of the
sources of the acid and alkaline matter eliminated from water by
voltaic action — the nature of electrical decomposition and transfer—
the relations between the electrical energies of bodies and the che-
mical affinities — a general development of the electro-chemical laws,
and their application. He thus concludes what Dr. Paris justly
styles one of the most masterly and powerful productions of scientific
genius —
' Natural electricity has hitherto been little investigated, except in the
case of its evident and powerful concentration in the atmosphere. Its
slow and silent operations, in every part of the surface, will probably be
found more immediately and importantly connected with the order and
economy of nature ; and investigations on this subject can hardly fail to
enlighten our philosophical systems of the earth, and may possibly place
new powers within our reach.'
Dr. Paris asserts that accident, which so mainly contributed to
former discoveries in electricity, had no share in conducting Davy
to the truth in this instance, but that he unfolded, with philosophic
caution and unwearied perseverance, all the particular phenomena
and details of his subject, and with the comprehensive grasp of
genius caught the plan of the whole.
Buonaparte having founded a prize of three thousand francs (about
£120), to be adjudged by the Institute, for the best experiment
which should be made in each year on the galvanic fluid, and another
of sixty thousand francs to the person who, by his experiments and
discoveries, should advance the knowledge of electricity and galva-
nism as much as Franklin and Volta did — the first prize was
awarded to Davy, about twelve months after the publication of his
first Bakerian Lecture, for his discoveries announced in the Philoso-
phical Transactions of 1807. When the bitter animosity which
France and England mutually entertained towards each other at this
period is recollected, the award was not more honourable to him who
received the prize than to those who gave it.
In November, 1807, his second Bakerian Lecture was read, in
which he announces the discovery of the metallic bases of the fixed
alkalies —
' a discovery immediately arising from .the application of voltaic electri-
city, directed in accordance with the electro- chemical laws he had deve-
loped. Thus having, in the first instance, ascended from particular
phenomena to general principles, he now descended from those principles
to the discovery of new phenomena ; a method of investigation by which
he may be said to have applied to his inductions the severest tests of
truth, and to have produced a chain of evidence without having a single
link deficient. Since the account given by Newton of his first discoveries
in optics, it may be questioned whether so happy and successful an in-
stance of philosophical induction has occurred.'
Dr. Paris, as before, gives a detailed account of the contents of this
Life of Sir Humphry Davy. 359
lecture, which we regret we have not space to copy. In the lecture,
Davy observes, that * an historical detail of the progress of the inves-
tigation, of all the difficulties that occurred, of the manner in which
they were overcome, and of all the manipulations employed, would
far exceed his limits/ upon which Dr. Paris observes that, * to the
chemist, every circumstance connected with a subject of commanding
importance is pregnant with interest;' and having, by permission of
the managers of the Royal Institution, obtained leave to examine and
make extracts from the Laboratory Register, he obtained the following
interesting clue to ' the intellectual operations by which his mind
ultimately arrived at the grand conclusion.' With these interesting
MS. volumes we hope to make the reader acquainted in a future
page of this Journal — in the meantime we shall follow Dr. Paris : —
4 It appears from this register, that Davy commenced his inquiries into
the composition of potash on the 16th, and obtained his great result on
the 19th of October, 1807. His first experiments, however, evidently did
not suggest the truth ; he does not appear to have suspected the nature
of the alkaline base until his last experiment, when the truth flashed
upon him in the full blaze of discovery. His first note, dated the loth,
leads us to infer that he acted on a solid piece of potash, under the sur-
face of alcohol, and several other liquids in which the alkali was not
soluble ; and that he obtained gaseous matter which he called at the mo-
ment " alkaligen gas," and which he appears to have examined most
closely, without arriving at any conclusion as to its nature. On the fol-
lowing day, he, for the first time, would seem to have developed potassium
by electric action on potash, under oil of turpentine, for the note records
the fact of " the globules giving out gas by water, which gas burnt in
contact with air ;" and then follows a query — " Does if (the matter of
the globules) " not form gaseous compounds with ether, alcohol, and the
oils?" Here then he evidently imagined, that the matter of the globules,
which he had never obtained from potash, except when acted upon under
oil of turpentine, had formed gaseous compounds with the ether, alcohol,
and oils, in his previous experiments, and given origin to that which he
had termed " alkaligen gas" He then leaves the consideration of this
gas, and attacks the unknown globules, which probably did not present
any metallic appearance under the circumstances he saw them, for they
must have been as minute as grains of sand. I rather think that he com-
menced his examination by introducing a globule of mercury, and uniting
it with a globule of the unknown substance, for his note says — " Action
of the substance on mercury, forms with it a solid amalgam, which soon
loses its alkaligen in the air/' And from the note which succeeds, he
evidently considered this alkaligen (potassium) volatile, as he says, " it
soon flies off on exposure to the air."
' October 19. — It is probable that, in consequence of the property which
the unknown substance displayed of amalgamating with mercury, he de-
vised his experiment of the 19th. He took a small glass tube, about the
size and shape of a thimble, into which he fused a platinum wire, and
passed it through the closed end. He then put a piece of pure potash
into this tube, and fused it into a mass about the wire, so as entirely to
defend it from the mercury afterwards to be used. When cold, the potash
was solid, but containing moisture enough to give it a conducting power ;
he then filled the rest of the tube with mercury, and inverted it over the
trough: the apparatus being thus arranged, he made the wire and the
mercury alternately positive and negative ; — and now, conceiving that I
360 Analysis of Books.
have sufficiently explained his brief notes, the reader shall receive the
result in his own words : on the same day he decomposed soda with
somewhat different phenomena/
Dr. Paris has given a fac-simile of the minute in Davy's hand-
writing of his successful experiment of October the 19th. It is
highly interesting and characteristic, but should have been accom-
panied by the substance of it in print, for it is not every one who will
be able to decipher it. It runs thus: —
' Oct. 19.— When pofash was introduced into a tube having a platina
wire attached to it, and fixed into the tube so as to be a
conductor, i. e.y so as to contain just water enough, though
solid, and inserted over mercury, when the platina was made
negative, no gas was formed, and the mercury became oxy-
dated, and a small quantity of the alkaligen was produced
round the platina wire, as was evident from its quick inflam-
mation by the action of water. When the mercury was made the negative,
gas was developed in great quantities from the positive wire, and none
from the negative mercury, and this gas proved to be pure OXYGENE. —
CAPITAL EXPERIMENT, proving the decomposition of POTASH.'
Those who knew Davy will best conceive the enthusiasm with
which this hasty record of his success wras dashed off, and will re-
cognise st/pixa in his ' capital experiment !'
(To be continued.)
I. Planta Asiaticce Rariores ; or Descriptions and Figures of a
select number of unpublished East India Plants. By N. Wallich,
M.D. Vol. I. folio. London, 1830. Treuttell and Co.
II. A numerical List of dried Specimens of Plants in the East
India Company's Museum, collected under the superintendence
of N. Wallich, of the Company's Botanic Garden at Calcutta.
Folio, pages 1—93, Nos. 1 — 3285; still publishing. (For
private distribution only.)
IF we were to select one country in preference to another, as
illustrative of the gigantic strides that have been taken by
modern science, India and its vegetation should be our theme —
India, which in its vast extent comprehends the climate of the
equator and of the Pole, stretching from the classical mountains of
Emodus on the north, to the ancient Tuprobane, and the sultry
islands of the Indian Archipelago on the south ; and from the rose
gardens of Amedabad, and the holy fountains and luxurious palaces
of Cachrnere on the west, to the frontiers of the celestial empire and
tlie burning shores of Arracan,.Pegu, and Martaban on the east;
embracing regions of eternal snow among the craggy summits of the
Himalaya and Nilgherry ; parched plains, where the sun glares with
his fiercest rays in Hindostan ; and including all those gradations
and diversity of climate which are the usual characteristics of an
entire quarter of the globe, rather than of a country subject to the
control of a single power, and distinguished by a single name ; — a
vegetation which seems, at first sight, to be in direct contradiction to
On the Botany of India. 361
any known law that regulates the embellishment of the face of
nature ; where the orange and the lime, the shaddock, the pine-
apple and the banana, grow almost side by side with the oak, the
bramble, and the chesnut; which, in one district, consists of roses,
elms, currants, raspberries, and wild flowers most similar to those of
Europe; and in another, is so entirely tropical, that the trees are
mangosteens and mangoes, and their inhabitants the parasitical
loranthus, or the fantastic orchis, while the woods are of teak and
sissoo, choked up by huge lianes ; in which the sensible properties
are so elaborated, that the very nettles become deadly, forest trees
produce blindness, by mere contact with their juices, the poisons are of
unheard-of virulence, and yet every sense is delighted by the fragrance
of flowers of the most splendid colours, or by the rich flavour of the
most luscious fruits.
The botany of this remarkable country has not failed to excite
attention from the earliest periods. To say nothing of the Arabians,
who first introduced ginger from Calicut to Spain — who described
the pepper plant that climbs upon other trees, hiding its fruit beneath
its leaves, lest the former be scorched up — who brought the sugar-
cane from the banks of the Ganges ; discovered the true camphor
tree of Sumatra ; distinguished the rhubarb that grows on the con-
fines of China from the rheum of the Greeks ; and made known the
tamarind, the cotton plant, the tea tree, the nutmeg, and the cinna-
mon ; and to pass by the now-forgotten names of Garcias ab Orta,
Acosta, I^inschoten, and Jacob Bont, there are two works that
especially claim our attention.
In x the middle of the seventeenth century, a Dutch Viceroy of
Malabar, named Henry van Rheede tot Drakenstein, collected by
means of Brahmins, missionaries, and others, a great store of draw-
ings and descriptions of the more important plants of his govern-
ment, which were subsequently published between the years 1676
and 1703, in twelve volumes, folio. Like the ' Flora Batava,' now
publishing at the expense of the King of the Netherlands, the skill
of the subordinate agents was by no means commensurate with the
liberality of their princely employers, whose treasures were unfor-
tunately lavished upon a work that was far from answering to the
charges that were incurred in its publication. About seven hundred
indifferent figures, accompanied by miserable descriptions, were the
whole result of Van Rheede's patronage.
About the same time, the Flora of Insular India was investigated
by George Everhard Rumf, a Dutch merchant and governor of
Amboyna, whose collections were published in seven volumes folio,
by John Burmann, between 1741 and 1751. Unlike Van Rheede,
Rumf appears to have been a skilful botanist for his time, as well as
a munificent patron ; and hence both the figures and descriptions
of the * Herbarium Amboinense,' as his work is called, are of a
character far superior to that of his predecessor. Like all drawings
of natural history of the day, the figures are inaccurate in their
details, but they are far from bad general representations ; the
362 Analysis of Books.
descriptions are written with care and minuteness, while the uses to
which the planls are applied are explained in a manner that might
serve as a model for a modern flora. These two works, with the
Thesaurus Zeylanicus, of Burrnann, compiled in 1737, from the ma-
terials collected by Paul Hermann, a Dutch Physician ; the Flora
Zeylanica, of Linnaeus ; and the Flora Indica, of Burmann, the
younger, were the basis, till of late years, of our knowledge of Indian
botany.
The whole of these publications did not, we believe, carry the
flora of India beyond two thousand species, of which, those only
that had been well figured could be said to be known to science,
so defective were the 'modes of description formerly employed.
Thus, after two thousand years that India had been constantly open
to Europeans, or in three hundred years from the period that the
Cape of Good Hope was first doubled by the Portuguese, the total
number of species that the enterprize of naturalists and the wealth
of their patrons, had accumulated in the boundless regions compre-
hended under the name of India, did not equal one half the flora of
France. Modern botanists have done in a few years what their
predecessors had failed to accomplish in centuries.
The principal cause of this progress is attributable to the powerful
patronage of the English East India Company, who, from the
period of their foundation of a botanic Garden at Calcutta, about the
year 1785, have been the constant promoters of investigations of the
natural history of their Indian possessions. Under these auspices
collections of great extent were formed by several individuals in
their service, particularly by Drs. Roxburgh, Russell, and Hamilton ;
while the addition of native draughtsmen to their botanical esta-
blishment laid the foundation of a series of drawings, unrivalled
for extent and accuracy. A portion of these was published several
years since, under the title of' Plants of the Coast of Coromandel,'
in three volumes folio, containing three hundred coloured figures ;
and vast quantities of dried specimens were deposited, by the Com-
pany's orders, in the hands of the Linna?an Society, and of the late
Sir Joseph Banks; among whose unarranged collections, we under-
stand, they still are to be found.
It was not, however, till the year 1815 that the powerful impulse
was communicated to the prosecution of botanical researches in
India, which has led to its present remarkable state. At that time
a Danish gentleman, whose works stand at the head of this article,
was appointed to the charge of the Calcutta garden ; and from this
period new vigour seems to have been infused into every depart-
ment. The preparation of drawings in the garden was prosecuted
with increased energy, and, under the new direction, with an
accuracy and beauty which had never before been seen in India.
The collection of living plants augmented rapidly, as was attested
by large and constant exportations of seeds and plants, as presents
from the Company, to public and private gardens in Europe. Irt
this way great benefit has accrued to Great Britain : independently
On the Botany of India. 363
of the vast numbers of hothouse plants of which every garden now
enjoys the advantage, of late years those valuable trees and beau-
tiful shrubs and flowers that, inhabiting the snowy mountains of
Nipal, find a congenial climate in Great Britain, have begun to
adorn our gardens. Dried specimens continued to be sent home,
and in such abundance, that a general distribution was some years
since entrusted by the Company to their officers in the museum of
the India House, by which the botanists of this country exten-
sively benefited. These collections had been chiefly formed by the
personal visits of Dr. Wallich to various parts of our Indian pos-
sessions. The high lands of Nipal were traversed in 1820 and
1821; the islands of Penang and Sincapur were visited soon after-
wards; the timber forests of Oude and llohilcund were explored in
1825 ; and, finally, the kingdom of Ava, and the coasts of Tenas-
serim and Martaban, were the subject of personal investigation by
this indefatigable naturalist in 1826 and 1827. Besides this, the
Company's residents, plant-collectors, travellers, physicians, and
others, all contributed, some (as the late Dr. Jack and Mr. Colebrooke)
very extensively, towards the completion of the investigation. The
result of these labours has been an accumulation of upwards of 8000
species, of which, if allowance be made for a deficiency in the insular
species, near 7000 must have been discovered within the last forty
years. A portion of these have been made known in the Flora Indica
of Carey and Roxburgh ; a further number have been published by
several of the working botanists of the day, and fifty were figured by
Dr. Wallich in his Tentamen Florae Indira Illustrate. Nothing, how-
ever, really worthy of the immense power that had been put in action
to collect these materials, had been undertaken, when ill health ren-
dered it advisable that the superintendent of the Botanic Garden,
Calcutta, should visit England, and it was then determined that his
collections should accompany him. In the true spirit of genuine
science, collecting nothing for himself alone, and everything for the
advantage of his favourite pursuit, the harvest of twenty years had
been supposed to have been nearly exhausted by his numerous remit-
tances to Europe ; but when it was known that the mere remains of
Dr. Wallich's gigantic herbarium occupied nearly forty huge chests,
weighing almost thirty tons, and that countless thousands of dupli-
cates still remained in his possession, the utmost anxiety was mani-
fested to know in what way the East India Company would deter-
mine that they should be disposed of. That everything which the
most exalted liberality could suggest might be anticipated was by no
one doubted, nor has the public expectation been disappointed.
The same spirit that directed the formation of these collections
presided over the councils of the company on their arrival. It was
directed that the most select of the new species should be published
from the drawings, and that the duplicate specimens should be
divided * among the principal public and private museums of
Europe and America.' Of the two works that stand at the head of
this article, the first is the result of the former part of the plan, and
304 Analysis of Books.
the second of the latter. We shall offer a few remarks upon them
respectively.
The first volume of the Plantre Asiatics Rariores contains ninety-
six species, represented in lithography, and coloured. Nearly all
the drawings from which these figures have been taken were made
in India by native artists attached to the Botanic Garden ; a very
small number has been prepared in England. Onr limits preclude
our quoting all the subjects that the volume comprehends ; refer-
ring, therefore, the scientific botanist to the work itself, we select a
few of the subjects that are likely to be most interesting to the
general reader.
The two first plates illustrate the Amherstia nobilis, a Burmese
tree, named in honour of the Countess and Lady Sarah Amherst,
remarkable for bearing an elegant ash-like foliage, half hidden
amidst which hang bunches of the most brilliant scarlet and
yellow blossoms, each with its scarlet stalk nearly six inches in
length. The Hindoos offer the flowers at the shrine of Buddha.
For splendour of colouring and elegance of form, this plate is unri-
valled. It is the high priest of the vegetable world, clothed in an
investiture more splendid than that of the most gorgeous religion of
mankind. Tab. 4, is Hibiscus Lindlei, a fine species, with large
bright purple flowers, now cultivated in England. Tab. 9, Curcuma
Roscoeana, is a plant with spikes of scarlet bracteaB six or seven
inches long, unrivalled for beauty among the ginger tribe. Tab. 11
and 12 represent theZit-siof the Burmese (Melanorhrea usitatissima),
from which is obtained that poisonous but invaluable black varnish
with which China and India toys arid utensils are coated. From
the account of this tree we extract the following: —
* The first time I met with this very interesting tree was at a small
village below Prome, on the river Irawaddi, where a few had been
planted ; and on my return from Ava I found it again in abundance on
the hills surrounding the first mentioned town ; but in both instances the
trees were without any fructification. In the Martaban province I had
the satisfaction of seeing the trees in great numbers in March, 1827, on a
small acclivity rising behind the town of Martaban. They were loaded
with bunches of red, nearly ripe, fruit, but were not very large, few only
exceeding thirty feet in height, with a short trunk measuring not more
than four or five feet in circumference. The leaves had entirely fallen
off, and strewed the ground in every direction. At Neynti, a village on
the Attran river, behind the military station at Moalmeyn, I also observed
a few trees; and lastly, on the Saluen river towards Kogun. Here they
were of greater dimensions than those just mentioned ; one of them being
forty feet in height, with a stem twelve feet long, and eleven in girth at
four feet above the ground. One of my assistants brought me fruit-
bearing specimens from Tavoy on the Tenasserim coast. Before leaving
Bengal I had an opportunity of identifying our tree with the majestic
Kheu, or varnish tree of Munipur, a principality in Hindustan, bordering
on the north-east frontier districts of Sillet and Tippera. Mr. George
Swinton, Chief Secretary to the Bengal Government, (to whose kind-
ness I ara indebted for much valuable information concerning the produce
of this and other useful trees of India,) obtained for me a supply of ripe
On the Botany of India. 3G5
fruits from thence, which differed in no respect from those I had seen at
Martaban. They vegetated speedily, and produced plants similar to those
\ve already possessed. Captain F. Grant, who has a military command
at Munipur, had the goodness to furnish the following particulars. The
tree grows in great abundance at Kubbu, an extensive valley in the above
mentioned principality, forming large forests in conjunction with the two
staple timber-trees of continental India, the saul and^teak (Shorea robusta
and Tectona grandis), especially the former. Numbers of the gigantic
woodoil-tree (Dipterpcarpus) are also found in company with if. The
size of it varies, but in general it attains very large dimensions. Captain
Grant speaks of trees having clear stems of forty-two feet to the first
branch, with a circumference near the ground of thirteen feet; and he
mentions that they are known to attain a much greater size. All the
individuals grow in the same manner, that is, they reach a great height
before throwing put any branches. Our tree belongs to the deciduous
class, shedding its leaves in November, and continuing naked until the
month of May ^during which period it produces its flowers and fruit. During
the rainy season, which lasts for five months, from the middle of May
until the end of October, it is in full foliage. Every part of it abounds in
a thick and viscid greyish-brown fluid, which turns black soon after coming
in contact with the external air. In the Edinburgh Journal of Science,
vol. viii., pp. 96 and 100, there are two interesting articles, containing
valuable information concerning the varnish produced by our tree, and
its deleterious effects on the human frame. It is a curious fact, that, to
my certain knowledge, the natives of the countries where the tree is indi-
genous never experience any injurious consequences from handling its
juices : it is strangers only that are sometimes affected by it, especially
Europeans. Both Mr. Swinton and myself have frequently exposed our
hands to it without any serious injury. I have even ventured to taste it,
both in its recent state and as it is exposed for sale at Rangoon, and have
never been affected by it. It possesses very little pungency, and is en-
tirely without smell. I know, however, of instances where it has produced
extensive erysipetalous swellings attended with pain and fever, but not of
long duration. Of this description was the effect it had on the late Mr.
Carey, a son of the Rev. Dr. W. Carey, who resided several years in the
Burman empire. Among the people who accompanied me to Ava, both
Hindoos and Mahomedans, no accident happened, although they fre-
quently touched the varnish, except in a slight degree to one of my assist-
ants, whose hand swelled and continued painful during two days. Dr.
Brewster informs me that, after resisting its effects for a long time, it at
length attacked him in the wrist with such violence that the pain was
almost intolerable. It was more acute than that of a severe [burn, and
the doctor was obliged to sleep several nights with his hand immersed in
the coldest water. He considers it a very dangerous drug to handle.
One of his servants was twice nearly killed by it.'
Tab. 22 and 23 are Dillenia scabrella and ornata, two noble trees,
remarkable for the large rich golden yellow blossoms with which
they are covered. Under Aphanochilus flavus, tab. 34, is the com-
mencement of a scientific arrangement of Indian Labiatae, by Mr.
Bentham, a performance of great importance to science. Eria pani-
culata, tab. 36, Dendrobium formosum, tab. 39, and D. densiflorum,
tab. 40, are magnificent air-plants, growing in damp forests on the
lower mountains of India. Tab. 41, Aconitum ferox, is a frightful
VOL, I. FEB, 1831. 2B
366 On the Botany of India.
poison called Vislia, Visli, or Bikh, of which the following is some
account : —
* This dreadful root, of which large quantities are annually imported,
is equally fatal when taken into the stomach, or applied to wounds, and
is in universal use for poisoning arrows ; and there is too much reason to
suspect, for the worst of purposes. Its importation would indeed seem
to require the attention of the magistrates. The Gorkhalese pretend that
it is one of their principal securities against invasion from the low coun-
tries ; and that they would so infect all the waters on the route by which
an enemy was advancing, as to occasion his certain destruction. In case
of such an attempt, the invaders, no doubt, ought to be on their guard ;
but the country abounds so in springs that might be soon cleared, as to
render such a means of defence totally ineffectual, were the enemy aware
of the circumstance. This poisonous species is called Bish or Bikh, and
Hay day a Bish or Bikh; nor am I certain whether the Metha ought to
be referred to it, or to the foregoing kind. By referring to the experiments
of Professor Orfila, in his General Toxicology, and of Mr. Brodie, in the
Philosophical Transactions, it will be seen that the symptoms produced
by the Aconitum napellus are very similar to those produced by the
Aconitum ferox. Hence, then, it is most probable, that both species
contain the same active principle ; but the A. ferox must contain it in
much greater quantity, as its effects are so much more powerful. Indeed
the alcoholic extract of this root appears to be nearly equal in power to
Strychnine, Upas antiar, Upas tieute, and Woorara poisons. That it
is equal in power to Strychnine, I can speak from numerous experiments
which I have made with this latter ; but with respect to the activity of
the Upas and Woorara poisons, I can only speak from the experiments
of Ortila, Brodie, and others.'
Ruellia gossypina, tab. 42, is a superb species, with leaves covered
with dense wool, and deep sky-blue flowers growing in numerous
panicles. Quercus spicata, tab. 46, is one of those gigantic oaks that
give a kind of European air to the flora of Nipal ; it bears its acorns
in spikes a foot long. Mucuna macrocarpa, tab. 47, is a bean with
flowers an inch and a-half, and pods afoot and a-half long: we are
told that the beauty of the blossoms compensates for their hairs en-
tering the skin and causing an intolerable burning. Justicia venusta,
tab. 66, is a charming branched plant with elegant panicles of rich
purple blossoms : it is now cultivated in England. Jilscynanthus
(jEsjchynanthus ?) ramosissima, tab. 71, is a parasitical shrub, bearing
umbels of orange and scarlet flowers, resembling our trumpet honey-
suckle, but scentless. Argyreia festiva, tab. 76, is a gigantic bind-
weed, with stems as thick as the wrist. Pongamia atropurpurea,
tab. 78, a vast tree bearing bunches of such inky purple flowers as
to resemble nothing so much as a plant in mourning ; and Bombax
insigne, tab. 79 and 80, is a magnificent cotton tree with superb
vivid red flowers, which fall from the trees in such profusion as to
form a thick bed of living fire. Wightia gigantea, tab. 81, is one of
those huge arborescent climbers, whose embrace is death, scrambling
to the tops of the highest trees, and overwhelming them with the
weight of their branches ; and Oxyspora paniculata, tab, 88, is re-
On the Botany of India. 367
presented as a common shrub in Nipal, producing large panicles of
blood-red blossoms. Almost all the foregoing, surpassing as is the
loveliness of some of them, arc eclipsed by the Bignonia multijuga,
tab. 95 and 96, a large forest tree found on the mountains of Sylhet,
bearing immense woody panicles of flowers resembling those of the
common Catalpa. And, finally, Begonia pedunculosa, tab. 97, is a
lovely little herbaceous plant, which seems, from its stems and leaves,
as if nature had intended them all for flowers.
We learn, from the preface, that this work appears under the im-
mediate patronage of the East India Company ; we congratulate the
author that he has such patrons, and the Company that they have
such a servant.
We have already stated that the second part of the Company's
plan was that of distributing throughout the whole scientific world
the immense collections which they had caused to be formed at such
great charge to themselves, and such incredible personal exertion
on the part of their civil servants. The whole of the details of
executing this gigantic scheme were of course entrusted to Dr.
Wallich, who judiciously adopted exactly the mode that would be
most agreeable to a liberal-minded man. He invited all the
botanists of Europe to co-operate with him in his enterprise, offer-
ing one tribe to this, and another to that person, taking care that in
all cases the different families should be placed in the hands of
those who were known by their published works to be best ac-
quainted with them. What has been the effect? England has
seen the learned men of Germany, Russia, and France, repairing
to her shores to assist in this splendid project, and those of all
nations enrolling themselves in the list of contributors to the noble
enterprise of the British East India Company ; she has beheld men
of all parties, of all countries, concurring in the prosecution of it,
and the great lords and princes of the land supporting it by their
countenance and assistance.
May the example of the British East India Company, in regard
to the collections of the Botanic Garden, Calcutta, be followed in
all the public establishments of the United Kingdom, and in every
department of their own ! May the guardians of our national insti-
tutions direct a similar application to be made of the objects of
science in their possession; and may our public functionaries destroy
for ever, the pernicious practice of collections formed at the expense
of the public purse, and by the authority of the British govern-
ment, serving no other purpose than that of exclusively augmenting
some single collection!
The second work at the head of this article is a numerical cata-
logue of the species that are thus distributed by the East India
Company.
2B2
( 368 )
FOREIGN AND MISCELLANEOUS INTELLIGENCE.
§ I.— MECHANICAL SCIENCE.
1. ON THE DISCHARGE OP A JET OF WATER UNDER WATER. —
(R. W. Fox, Esq.)
THE following letter is addressed to tlie Editors of the Philosophical
Magazine.
* I am not aware that it has been before noticed, that a jet of
water discharges the same quantity, in water, as in air, in a given
time, without reference to the depth or the motion of the water,
at least within certain limits. Thus when the experiment was tried
with a head of water six feet high, the same orifice discharged equal
quantities in equal times, in air, in still water, and in a rapid stream,
moving at the rate of about six feet in a second ; the jet having in
one case been turned with the current, and in another against it: and
when, by lengthening the-tube, the aperture was submerged to the
depth of fifteen feet, the effect was the same as at the surface, under
the pressure of an equal column above it. These results have been
obtained by my brother Alfred Fox and myself, and you may per-
haps think them deserving a place in your Magazine, if they should
appear to you to be new.
* We sometimes coloured the water, when the jet appeared to pass
unbroken to a considerable distance under the water*.'
2. ON PREVENTING THE DISCHARGE OP A BULLET FROM A GUN
BY THE FINGER.
At the sitting of the Helvetic Society of Natural Sciences of the
28th July last, a letter was read from Dr. Flachin of Yverdun,
relative to an experiment before mentioned to the society, in which
the ball was prevented from leaving the bottom of a musket when
the gunpowder was fired, simply by putting the ramrod upon the ball,
and the end of the finger upon the ramrod. He supposes the effect
may be explained by the circumstance, that near the charge the ball
has a very small velocity compared to that impressed upon it by the
expansive force of the gases from the fired gunpowder, when exerted
during the whole of the time in which it is passing along the barrel.
It is well known that the effect thus accumulated is the reason why
long pieces carry further than short ones, and why the breath of a
man, which cannot exert a pressure of more than a quarter of an
atmosphere, may, by means of a tube, throw a ball to the distance of
sixty steps. The experiment above requires great care, especially as
to the strength of the piece, which is very liable to burst in the per-
formance of the experiment f.
Vol. viii, p. 342, t Bib, u»fr.; 1830, p, 447
Mechanical Science. 369
3. CLEMENT'S EXPERIMENT — EASY MODE OP REPEATING IT.
The very curious, and apparently paradoxical experiment, first de-
scribed by Clement, in which air, gas, or steam, issuing with force
from a hole in a flat surface, did not blow away a platter or other flat
and extended body, but rather caused its adhesion, has been repeated
since in a great variety of forms. M. Hachette contrived a simple
little apparatus, by which every one was put in possession of the power
of witnessing the effect: and such facilities are valuable, because they
rapidly extend the knowledge of curious effects, and cause them to be
still more extensively pursued and investigated. The experiment
may be still further simplified in the following manner. When the
fingers of the open hand are retained as close to each other as they
can be, still there are certain slit-like intervals between them extend-
ing from joint to joint. Let the hand be held horizontally with the
palm downwards, apply the lips to the interval between the second
and third fingers nearest to their roots, and then blowing with force,
a strong jet of air will of course issue from the aperture at the under
side of the hand. Now, put a piece of paper or a card three or four
inches square against that aperture, and again blow ; it will be found
that the paper will neither be blown away, nor fall by its own weight,
but will be pressed upwards against the hand and the issuing current
of air, so long as that current continues. The moment it ceases, the
paper will fall away by its own gravity, in obedience to the ordinarily
active laws of nature.— M. F.
4. BROWNE'S MOVING MOLECULES.
Muncke, of Heidelberg, finds the following a simple and easy mode
of showing the motions of particles ; — triturate a piece of gamboge
the size of a pin's head in a large drop of water on a glass plate ;
take as much of this solution as will hang on the head of a pin,
dilute it again with a drop of water, and then bring under the micro-
scope as much as amounts to half a millet-seed ; — there are then
observable in the fluid small brownish-yellow points, generally round
(but also of other forms), of the size of a small grain of gunpowder,
distant from one another from 0.20 to 1 line. These points are in
perpetual motion, varying in velocity, so that they move through an
apparent space of 1 line in from 0.5 to 2 or 4 seconds. If fine oil
of almonds be employed in place of water, no motion of the particles
takes place, but in spirit of wine it is so rapid as scarcely to be
followed by the eye. This motion certainly bears some resemblance
to that observed in infusory animals, but the latter show more of
voluntary action. The idea of vitality is quite out of the question.
On the contrary, the motions may be viewed as of a mechanical
nature, caused by the unequal temperature of the strongly illuminated
water, its evaporation, currents of air, heated currents, &c. If the
diameter of a drop be 0.5 of a line, we obtain, by magnifying 500
times, an apparent mass of water of more than a foot and a-half
370 Foreign and Miscellaneous Intelligence.
broad, with small particles swimming in it ; and if we consider their
motions magnified to an equal degree, the phenomenon ceases to be
wonderful, without, however, losing anything of its interest *.
5. EXACT MEASURE OP A DEGREE.
Ten thousand rubles (upwards of 1500/.) a year have been granted
by the Emperor of Russia for the continuation of the investigations
undertaken to obtain the exact measure of a degree. This work,
which, it is said, will last for ten years, is confided to the charge of
M. Struve, of Dorpat. Two staff officers, natives of Finland, Messrs.
Rosenius and Aberg, are already gone to their country for the pur-
pose of discovering the mathematical points of union between Hoch-
land and Tornea. M. Struve has projected a journey abroad, in
furtherance of this great undertaking f.
6. SvANBERG ON THE TEMPERATURE OP THE PLANETARY SPACE.
M. Fourier obtained, as one of the results of his important investi-
gations of the temperature of the earth, &c., that the temperature of
the planetary space was equal to — 50° C., or ( — 58° F.), and arrived
at the conclusion also, that the earth has arrived at its lowest degree
of temperature, or that point below which it could not sink. M.
Svanberg has arrived at a result so nearly the same, as to be very
remarkable, especially considering that his mode of investigation
was altogether of a different nature, and had for object atmospherical
refraction. He wished to examine completely the problem of atmos-
pherical refraction, and also the various hypotheses which have been
put forth to determine its quantity. Some of these appeared sufficient
for astronomical purposes, but having concluded their investigation,
M. Svanberg wished to view the subject in a physical point of view,
and then arose the difficulty of being able to determine, for each
temperature observed at the surface of the earth, the law of the
corresponding distribution of heat in the atmosphere, under the
hypothetical condition of perfect equilibrium, and also the law accord-
ing to which the temperature diminishes at different elevations above
the level of the sea.
','In this examination, as in others (says M. Svanberg) where a
greater or smaller number of natural phenomena are to be subjected
to a mathematical formula, great inconvenience occurs, from the
circumstance that an infinity of functions of various forms are capable
of representing a finite number of observations, and that the real
accuracy of the formula adopted can only be judged of by the ac-
cordance which it presents with those observations which have not
served for the determination of its constants, by the number and the
nature of the observations to which they may apply. Hence it
* Jameson's Journal, 1830. f Bull, Geog. xiii. p, 30G.
Mechanical Science. 371
results, that one can never have a general rule by which to arrive
directly at the point required, and that the work is obliged to be
commenced with an hypothesis which, at a later period, is to be sub-
jected to criticism from the observations. At the same time, the
adoption of an hypothesis does not depend upon accident, but
requires the most intimate knowledge of mathematical forms in their
greatest extent, otherwise the progress would only be from error to
error. One rule, however, should be observed — it is, to commence
by trying those formulae which require the determination of the
smallest possible number of arbitrary constants.
4 Guided by these considerations, and by the relation between light
and heat so evident in the power which the solar rays possess of
producing heat by their passage through bodies but little transparent,
I commenced by supposing that the planetary space, with a perfect
transparency, would undergo no change of temperature, neither by
the effect of light nor radiant heat ; and that therefore the elevation of
temperature above that of the etherial regions can only commence at
the limits of the atmospheres of the planets. A necessary result is,
that the rate of change of temperature at a height infinitely above
the surface of the earth is always proportional to the rate of the cor-
responding change in the capacity which the atmosphere possesses
of absorbing light. Upon these considerations I expressed the tem-
perature of the atmosphere by means of a formula, which applies to
any height above the surface of the earth, and which contains only
two arbitrary constants ; one, which is also a function of the time, is
always determined by the immediate observation of the correspond-
ing temperature of the surface of the earth ; and the other, which
does not vary in relation to time, is the temperature of the planetary
space.
* The numerical determination of these constants requires exact
observations of the temperatures of isolated points, up to a consider-
able height above the earth's surface; but, unfortunately, these
observations are so difficult, that at present I could take advantage of
one only, that made by M. Gay Lussac, in his aerial voyage. It is
very much to be desired that this observation should be repeated,
especially in the neighbourhood of the equator, where atmospheric
variations are small, and where, consequently, the influence of acci-
dental circumstances are less to be feared. Nevertheless, the single
observation of Gay Lussac has given me — 4 9°. 8 5 C., as the tempera-
ture of the planetary space, a number which only differs one-seventh
of a degree from that obtained by M. Fourier, according to the laws
of heat, radiating from the solid globe, supposed to have arrived at
its state of fixed and invariable temperature.
* Without having much doubt as to the identity of light and heat,
or as to the accuracy of our photometrical knowledge, I thought it
would still be interesting to see the results which would be given by
setting out from the data of Lambert, on the absorption of light,
which, coming from the zenith, passes through the whole depth of
the atmosphere : establishing my calculation on the supposition that
372 Foreign and Miscellaneous Intelligence.
the differential of the augmentation of temperature is always pro*
portional to the portion of light absorbed. In this way I found that
the temperature of the planetary space was — 50°.35 C., and I acknow-
ledge the pleasure I felt at finding the remarkable accordance be-
tween these two results, and that of M. Fourier. The circumstance
strengthens my opinion, that the formula I have given for the
temperature of space deserves to be at least seriously examined. The
immediate results which follow, are, that the temperature diminishes
in a continually decreasing ratio as we ascend in the atmosphere, and
that at a given height this ratio is greater as the temperature at the
corresponding surface of the earth is higher.
* Although I had no intention of examining the formulae relative
to the determination of heights by barometrical observations, I. have
found, nevertheless, in the observations of M. Gay Lussac, that the
influence of the results I have obtained becomes sensible, in the
appreciation of heights equally great with that to which he rose,
though it is not necessary to take note of it in the estimation of
ordinary heights. The form of the function is to me very important,
because from it I deduce the refractive power of the atmosphere in
all the parts of the course pursued by light ; and as I have already
treated minutely the formula derived from it, for the definitive deter-
mination of the refractions themselves, so now I am in a condition
to investigate the problem in question by the powers of mathematical
investigation only, after having subjected it to the severest trials, by
means of the physical observations which bear upon it*.'
7. ON THE RELATION BETWEEN THE GENERAL DIRECTION OF THE
STRATIFICATION OP THE EARTH AND THE LINES OF EQUAL
MAGNETIC INTENSITY IN THE NORTHERN HEMISPHERE. — (M.
L. A. Necker)
An interesting paper on this subject has been presented to the Geneva
Society by M. Necker. Upon examining Captain Sabine's chart t
of the curves of equal magnetic intensity, he was struck by the
analogy of their direction with the form and position of the two
great continents upon which they were traced. The northern extre-
mities of these continents are somewhat symmetrical, and are placed
at the extremities of a line, which, passing over the earth's pole,
connects the two northern poles of magnetic intensity j the masses
of which the continents of Asia and North America are formed, have
an apparent tendency to extend themselves in the direction ef the
principal axis of the magnetic curves, and consequently on the same
line, a tendency which is more manifest in America where the differ-
ence between the relative dimensions of the two axes of these curves
is greatest. Finally, not only may the coasts of these continents be
observed to have a general disposition to conform to the direction of
* Bib. Univ., 1830, p. 367. Berzelius' Report.
f Bib, Univ., 1829, p. 212, or Journal of Science, 1829, July— Sept., page 1,
Mechanical Science. 373
the magnetic lines belonging to the pole situated on the one or
other continent, but in many cases the direction is nearly parallel,
and sometimes coincident with the direction of these curves. Thus
in Asia, the coast from the north of the Persian Gulf is continued to
Bombay, parallel to the curve ; the same is the case on the southern
coast of China, which, at the south-east, turns to the north with the
curve, and the latter follows exactly the direction of the long chain
of islands Leou Kiou, Niphon, Jeso, Seghalien, which really form
the eastern extremity of the ancient world.
In North America and elsewhere, M. Necker shows the same
association of forms. He then refers to the well-known observation,
that the geographical form of the earth is in direct relation to the
elevation of the ground — that it is, in fact, derived from the lines of
intersection made by the constant and uniform surface of the sea,
conjointly with the irregular and undulating surface of the solid
parts of the globe. Continents, islands, isthmus, &c., are parts
bounded by these intersecting lines. It is equally well known now,
and is receiving confirmation daily, that the elevation of the earth is
determined by the stratification of the mineral masses which com-
pose it, that is to say, that the assemblage of inclinations, or systems
of inclination, which constitute the elevation, is in constant relation to
the direction and inclination of the strata of the earth. It is to those
chains of mountains, more or less elevated or extended, from which
the inclined parts of a country descend, that the mineral strata also
conform ; and we have reason to believe that the axes of each of
those chains of mountains, or parallel set of strata, consist of un-
stratified masses of granitic or porphyritic rocks, the existence of
which is connected with the laws which reign over the stratification
of each region. All geologists generally admit that the direction of
the strata on different sides of a chain of mountains is sensibly parallel
to the direction of the chain itself.
From these considerations, it would appear, that if there is any
analogy between the configuration of the northern continents and the
direction of the curves of equal magnetic intensity, an analogy ought
also to exist between the magnetic curves and the direction of the
strata of which the earth is composed. M. Necker, therefore, pro-
ceeds to compare these curves with what is known of the stratification
of the earth in the northern hemisphere, and finds a striking coinci-
dence in direction. Thus the magnetic curve of 297 seconds traverses
Scotland in a direction S.W. to N.E., which is precisely the direction
he found the strata of that country to have when he personally ex-
amined them. The curve then passes to . Christiana, in Norway,
preserving the same direction ; and according to M. Buch, such is
the direction of the strata at Christiana. It traverses Sweden, where,
according to Hisinger, the N.E. direction of the strata still continues ;
but on arriving at the Gulf of Bothnia, the curve changes and turns
to the S.E. Here, and further on, correct observations of the direc-
tion of the strata are wanting, but the direction of the northern coast
of Russia, Lapland from North Cape to the White Sea, which coast
374 Foreign and Miscellaneous Intelligence.
is altogether rocky, and is prolonged from N.W. to S.E., is a cir-
cumstance in favour of the parallelism of the direction of the strata
and the magnetic curve.
Other curves, examined in a similar way, offered similar analogies ;
and it may be observed generally, that, in western Europe, the
magnetic curves of equal intensity, and the stratification, have both
a north-eastern direction ; whilst in eastern Europe they both have a
north-westerly direction.
That there are anomalies M. Necker admits, and notes amongst
them the Pyrenees in western Europe ; the part of eastern Europe
which, comprehending Styria, includes the mountainous portions to
the west and south-west of Vienna and the north-west of Hungary ;
and the various groups, consisting of central masses of granite,
clothed with mantles of stratified rocks.
The investigation is then carried on in North America, in Mexico,
and in Asia, where, as far as the present state of geological know-
ledge will admit, the same general relations are observed. The
longest chain of mountains in the world, namely, the Hymalaya, are
found to coincide in direction perfectly with the magnetic curve.
Although the account of these analogies and directions is very
incomplete, still M. Necker thinks it will be difficult to deny the
existence of a relation between the stratification of the earth, the
direction of the principal mountainous chains, the elevation of the
continents, and the curves of equal magnetic intensity ; and he thinks
it must be a point of no small interest to the geologist, to observe
the regular manner in which the mountains and mineral masses of
the earth arrange themselves symmetrically about the two points of
the northern hemisphere, which are nearly in the same places where
Professor Hansteen and Captain Sabine have recognised the two
poles of equal magnetic intensity*.
8. FORCE OF TERRESTRIAL MAGNETISM.
The following Table of the intensity of the earth's magnetic force
at certain places on the continent, is from the recent observations of
M. Quetelet, of Brussels, who was supplied with every facility of
determining these intensities with accuracy : —
Mean horizontal
Place of Duration of intensity, that Magnetic Total
Observation. 100 oscillations of Altona Inclination. Intensity,
of the Needle. being 1.
Berlin 39P.13 1.0301 68° .42' 2.836
Gottingen . . . 390 .72 1.0310 68 .39 2.832
Leipsic 386 .72 1.0524 58 . 8.2 2.827
Dresden 382 .53 1.0756 67 .41.3 2.833
Brussels 392 .13 1.0245 68 .56.5 2.851
Frankfort.... 385 .16 1.0614 67 .52 2.816
The places are arranged in the order of their latitudes, being
« Bull. Univ. 1830, p. 166.
Mechanical Science.
comprised between 52° 32' and 50° 7'. The instrument used was on
the model of that belonging to M. Hansteen, and employed by
Captain Sabine. -The needles were small cylinders of steel, pointed
at the extremities, and suspended in glass cases by silk filaments*.
9. AN ACOUSTIC RAINBOW.
Professor Strehlke states that a sounding-plate, covered with a
layer of water, may be employed to produce a rainbow in a chamber
which admits the sun. On drawing the violin bow strongly, so as
to produce the greatest possible intensity of tone, numerous drops
of water fly perpendicularly and laterally upwards. The size of the
drops is smaller as the tone is higher. The outer and inner rainbows
are very beautifully seen in these ascending and descending drops,
when the artificial shower is held opposite to the sun. When the
eyes are close to the falling drops, each eye sees its appropriate
rainbow, and four rainbows are perceived at the same time, particu-
larly if the floor of the room is of a dark colour. The square plate
on which Professor Strehlke made the experiment was of brass, nine
inches in length, and half a line in thickness. The experiment suc-
ceeds best tf, when a finger is placed under the middle of the plate,
and both the angular points at one side are supported, the tone is
produced at a point of the opposite side, a fourth of its length from
one of its angles. An abundant shower of drops is thus obtainedf.
10. COMPRESSION OF FLUIDS. — (Professor Oersted.)
From a series of experiments on this subject, M. Oersted was led
to the following results : —
i. The compressibility of fluids, up to the pressure of 70 atmos-
pheres, is proportional to the pressure.
ii. Up to the pressure of 48 atmospheres, no perceptible degree of
heat was developed in water.
iii. The compressibility of quicksilver does but very little exceed
the millionth part of its volume for every atmosphere.
iv. The compressibility of sulphuric ether is three times as great
as that of alcohol, twice that of sulphuret of carbon, and one and a
half that of water.
v. Water which contains salts in solution is less compressible
than pure water. At 32° F. pure water is by one-tenth more compres-
sible than at 55° F. ; at higher temperatures its compressibility also
decreases, though not to such an extent as between 32° and 55°.
vi. The compressibility of glass is very small, much less than that
of quicksilver.
Mr. Perkins found the compressibility of water more than double
that resulting from M. Oersted's experiments ; a difference which,
* Bull. Univ. 1830, p. 365.
f Poggendorff's Annal. 1830, No. 3.
376 Foreign and Miscellaneous Intelligence.
according to M. Oersted, must be accounted for by the circumstance
that, in Mr. Perkins's experiments, the compression was produced by
percussion, the force of which cannot be calculated.
11. PECULIAR APPEARANCE OF SATURN'S RING.
The second Number of Schweigger-Seidel's Jahrb., 1830, contains
the report of M. Schwabe, of Dessau, on the appearance of Saturn's
ring, which be repeatedly found at the eastern side to be more distant
from the body of the planet than on the west side. He had convinced
himself that the shadow of the planet had no influence on this ap-
pearance, which he had first discovered in 1827 with a 3J foot
refractor, and found his observations confirmed in 1829 by a 6 foot
refractor with 54 lines aperture. In the nights of the 21st of April
and of the 3rd, llth, and 20th of May, the inequality seemed to be
at its maximum, and appeared less in the intermediate nights. These
observations were also confirmed by those of Professor Harding.
$ II.— CHEMICAL SCIENCE.
1. DECOMPOSITION OF WATER BY ATMOSPHERIC ELECTRICITY.
M. Bonijol, conservator of the reading society of Geneva, has con-
structed many very delicate apparatus, by means of which water may
be readily decomposed by the electricity of the ordinary machine,
and also by atmospheric electricity. The electricity of the atmosphere
is gathered by means of a very fine point fixed at the extremity of
an insulated rod ; the latter is connected with the apparatus, in which
the water is to be decomposed, by a metallic wire, of which the
diameter does not exceed half a millemeter (^yth of an inch). In
this way the decomposition of the water proceeds in a continuous
and rapid manner, notwithstanding that the electricity of the atmos-
phere is not very strong. Stormy weather is quite sufficient for the
purpose*.
2. DECOMPOSITION BY ORDINARY ELECTRICITY.
M. Bonijol has also succeeded in decomposing potash and the
chloride of silver, by placing them in a very narrow glass tube, and
passing a series of electric sparks from the ordinary machine through
them. The electricity was conducted into the tube by means of two
metallic wires fixed into the ends. When a quick succession of
electric sparks had taken place for about five or ten minutes, the
* Bib. Univ, 1830, p. 213.
Chemical Science. 377
tube containing chloride of silver was found to contain reduced silver:
and when potassa had been submitted to the electric current, then
the potassium was seen to take fire as it was produced*.
3. ON THE DECOMPOSITION OP METALLIC SALTS BY THE VOLTAIC
PiLE, AND ON THE STATE OF CHLORIDES, IODIDES, &C. IN
SOLUTION.
Whilst experimenting with a voltaic pile of thirty pairs of plates,
M. Carlo Matteuci observed, that when the poles were plunged into
solution of common salt, they both evolved gas ; but that when in-
troduced into solution of sulphate of copper, although oxygen was
evolved as before from the positive pole, hydrogen ceased to be dis-
engaged at the negative pole, but metallic copper was there deposited.
Using various other metallic solutions, he found that those of lead
and silver, with some others, produced the same effect, 2. e. evolved
no hydrogen, but had the metals deposited in the metallic state,
whilst others evolved gas at the negative pole, and had their bases
deposited as oxides. Reasoning on the effect, he was induced to
conclude, that in the cases in question, the hydrogen separated at
the negative pole was employed in reducing the oxides of the metals ;
and hence its disappearance, and the deposition of the base in a
metallic state. To assure himself of the truth of this view, lie con-
structed a weak pile composed of only two elements, and incapable
of decomposing a weak solution of salt. A solution of nitrate of
silver is far more easily decomposed than water, as M. Becquerel has
shown, and such a solution was readily decomposed by this weak pile
of two elements ; and at the same time it was observed, that the
usual deposit of metallic silver did not occur, but an olive-coloured
layer of oxide of silver was produced. It is, therefore, sufficiently
proved, that the disengagement of hydrogen at the negative pole of
the pile ceases, only because that element is employed in reducing
the metallic oxides already separated from these acids by the action
of the pile. It is a striking case of the powers of nascent hydrogen
at common temperatures.
Having explained this appearance, M. Matteuci proceeded to
decompose the chlorides and iodides by means of the pile, with the
expectation of being able to deduce the nature of these compounds
when dissolved in water. If it were possible to decompose these
combinations by means of electric currents, incapable of decomposing
water, one might then justly conclude that their composition was not
changed by solution in that liquid. He, therefore, took a pile com-
posed of two elements only, charged with water rendered slightly
saline, and which had no power of decomposing water even a little
acidulated. The platina conductors were then dipped in a solution
of muriate of copper, and after some time, the negative conductor
• Bib, Univ. 1830, p, 213.
378 Foreign and Miscellaneous Intelligence.
was covered witli metallic copper, whilst the positive conductor
evolved bubbles of gas. Having replaced the latter conductor by one
of silver, it soon became covered with a yellow film gradually changing
to violet, which was considered as chloride of silver. The expe-
riment was repeated with the iodides of zinc and iron ; the platina
poles had scarcely touched the solutions before the iodine, with its
distinctive colour, appeared at the positive pole, and the metals were
reduced and deposited upon the negative pole.
' After these experiments it appears,' says M. Matteuci, c that we
may affirm with certainty, that these combinations, even when dis-
solved in water, do not change in their nature, and are not converted,
as is often imagined, into muriates, hydriodates, &c. of the oxides of
the metals present.'*
4. VOLTAIC TEST OF THE STATE OF METALS.
It is well known that Dr. Wollaston devised a beautiful little ar-
rangement to ascertain the conducting power of certain crystals
having metallic characters, and which ultimately proved to be
titanium. If a plate of copper be in contact with a plate of zinc,
and part of both plates be immersed in a dilute acid, the copper, by
its electric condition, decomposes water and becomes covered with
bubbles of hydrogen. If a piece of paper, or a card, be interposed
where the two metals were in contact, the copper loses this power
altogether, and no bubbles appear on it ; but if a small hole be made
in the paper or card, and a little piece of metallic matter put there,
so as to touch at once both the zinc and copper, then the latter has
its full power restored.
M. Macaire Prinsep has applied this test more generally ; and he
found, in the first place, that a metal was necessary to restore the
effect — lead, bismuth, tin, &c. reproduced the bubbles ; but sulphuret
of arsenic, rutilite or oxide of titanium, grey cobalt ore, and the
sulphurets of antimony, iron, tin, or lead, produced no effect. Por-
tions of meteoric stone from Aigle and Barbotan, by producing
bubbles, showed that they contained uncombined metal ; and the
method seemed competent to indicate, in all cases, whether the
metals used were free, or in a combined condition.
As lead gave bubbles, but the sulphuret of lead none, experiments
were made with lead, to which sulphur, in increasing proportions,
had been added : — T^, ^, J^, T\r, and TL of sulphur did not take
away the property from lead ; but when l of sulphur was used, no
bubbles appeared upon the copper. Then ascertaining the propor-
tions in the definite sulphuret of lead, he found them to be exactly
those which caused the evolution of bubbles to cease (86 lend
and 14 sulphur.) The same effect occurred with the sulphuret
of tin ; and hence it was concluded that chemical combination in
* Bib, Univ. li>30, p, 138.
Chemical Science. 379
determinate proportions was necessary to prevent this electric decom-
position, and that mixtures had no influence on the phenomena.
These results may be important to the mineralogist ; and M. Macaire
Prinsep, in illustration, concludes, that the grey cohalt ore of Luna-
berg, which is composed of cobalt, arsenic, and sulphur, contains
only sulphurets of the metals ; that, on the contrary, the metals
of aerolites, although sometimes found associated with sulphur, and
always with silica, exist neither as sulphurets nor silicates, but in
their metallic condition*,
5. POWERFUL ELECTRO-MAGNET CONSTRUCTED BY PROFESSOR MOLL.
If a piece of iron rod be bent into the form of a horseshoe mag-
net, and coiled round with a copper wire, so that the latter may form
a helix through which the voltaic current may be sent, the iron
becomes for the time a powerful magnet.
Professor Moll has repeated this experiment upon an enormous
scale. His galvanic apparatus was a copper cell, charged with
water, mingled with ^ of sulphuric and T^ of nitric acid, into which
was introduced a zinc plate exposing 11 square feet of surface to the
acid. His magnet was made of a cylinder of soft English iron, 1 inch
in diameter ; when bent into form, the interval between the ends was
8j inches: the copper wire forming the spiral was i of an inch in
diameter, and made eighty-three convolutions ; the weight of the whole
was 5lbs. A connecting piece, of the usual form, made of soft iron,
joined the two extremities of the horseshoe, and the ends of the spiral
were dipped in mercury for ready voltaic communication. The horse-
shoe was hung in the usual manner of magnets.
In the first experiment this arrangement sustained, first, 501bs., and
afterwards, with care, 76lbs. by its magnetic attraction. When the
suspended weight was small, it was found that the iron retained its
magnetism for a time after the voltaic communication was broken.
If, instead of merely breaking the direction, the electric poles were
reversed, then the reversion of the magnetism took place with ex-
traordinary rapidity. On effecting the change, the iron lost all
power, the weight fell off, but, with the rapidity of lightning, was
again attracted and sustained to an equal amount as at first.
The rapidity of this change is the more extraordinary, if compared
with the slowness and difficulty of charging the poles of a magnet,
of equal force, by the ordinary method. If, instead of a heavy weight,
a light steel needle be in contact with the poles of the electro-magnet,
then so rapid is the change that the needle never falls off, for the
attractive force is destroyed and re-established before the gravity of
the needle has time to remove it sensibly from its first position.
\Vlicn the piece of soft iron connecting the poles is held by the
hand during this change, the sensation is of the most extraordinary
» Bib. Univ. 1830, p. 146.
380 Foreign and Miscellaneous Intelligence.
kind. Powerful attraction is first felt ; this on a sudden fails, and the
hand with the iron gives way, but the force is so instantly renewed, that
the hand is violently drawn up again by an attraction as great as ever.
The moment the electric communication is completed, the iron is
magnetised to a maximum, and bears its greatest charge. On in-
creasing the voltaic apparatus in force, by adding to it another, ex-
posing 6 square feet of zinc, so as to make 17 square feet of surface
altogether, no increase of magnetic power was conferred upon the
arrangement ; nor by using a higher charge was any increase of
power obtained, the maximum effect of the iron had been developed
in the first instance. Whether the spiral were of copper or brass
wire, made no difference. When it was iron wire, -f^ of an inch in
diameter, and prevented from touching the curved soft iron by inter-
vening silk, the weight taken up was rather higher, being 861b.
A larger soft-iron horseshoe magnet was now made ; the iron
was 2J inches in diameter; the chord of its arc was 12J inches; the
spiral was brass wire ^ of an inch in diameter, and made 44 turns.
The magnet weighed 261bs. and its connecting piece 41bs. With
the voltaic apparatus of ] 1 square feet, this arrangement supported
1391bs. ; this was raised to 1541bs. by using an iron spiral, with silk
between it and the magnet. This is the maximum to which M. Moll
has carried "his experiments; but the force exerted is enormous, and
at the same time instantaneous ; and it is extraordinary to see an
arrangement, which at one moment can support this weight, lose all
its force merely by breaking or altering a distant contact and again
have it as fully renewed.
On trying to heighten the power of an ordinary steel magnet,
now capable of supporting 51bs., but formerly much more, these means
failed entirely : though left surrounded by the spiral for a long time,
its force remained at 51b. The powerful electro -magnets of soft iron
just described have, however, every power of ordinary magnets in
touching or affecting steel bars, or in strengthening and reversing the
poles of ordinary magnets.
There is a magnet in the Teylerian Museum at Harlem, which sup-
ports 2301bs. ; there are, perhaps, one or two other very powerful
ones, but except these, the electro-magnet of Professor Moll is the
most powerful of any known magnets, and yet is, probably, far short
of what might be effected by similar means*.
6. LAWS OF ELECTRICAL ACCUMULATION."
Mr. Han-is, of Plymouth, has made an extensive series of experi-
ments on the laws of the accumulation of ordinary electricity. The
details of these experiments, with illustrative plates, are published in
the Transactions of the Plymouth Institution, 1830. We have not
space for more than the conclusions at which he arrives.
i. An electrical accumulation may be supposed to proceed by
k* Bib, Univ., 1830, p. 19.
Chemical Science. 381
equal increments. A coated surface, charging in any degree short
of saturation, receives equal quantities in equal times, all other things
remaining the same. The quantity passing from the outer coating
is always proportional to the quantity added to the inner.
ii. The quantity of matter accumulated may be estimated hy the
revolutions of the plate of the electrical machine, supposing it in a
state of uniform excitation ; or it may be measured by the explosions
of a jar connected with the outer coatings. It is as the surface
multiplied by the interval which the accumulation can pass : when
the surface is constant, it is as the interval ; when the interval is con-
stant, it is as the surface. It is also as the surface multiplied by
the square root of the free action or intensity : when the surface is
constant, it is therefore as the square root of the attractive force.
iii. The interval which the accumulation can pass is directly pro-
portional to the quantity of matter, and inversely proportional to
the surface : it is as the quantity divided by the surface : if the mat-
ter and surface be either increased or decreased, in the same propor-
tion the interval remains the same. If, as the matter be increased,
the surface be decreased, the interval will be as the square of the
quantity of matter.
iv. The force of the electrical attraction varies in the inverse ratio
of the square of the distance between the points of contact of the op-
posed conductors, supposing the surfaces to be plane and parallel ;
or otherwise between two points which fall within the respective
hemispheres at a distance equal to one-fifth of the radius, supposing
the opposed surfaces to be spherical.
v. The free action or intensity is in a direct proportion to the
square of the quantity of matter, and in an inverse proportion to the
square of the surface : it is directly as the effect of an explosion on
a metallic wire, all other things remaining the same. If the matter
and the surface increase or decrease together, so in the same pro-
portion the attractive force remains the same. If, as the matter be
increased, the surface be decreased, the attractive force is as the
fourth power of the quantity of matter.
vi. The effect of an electrical explosion on a metallic wire depend*
exclusively on the quantity of matter, and is not influenced by the
intensity or free action. It is diminished by accumulating the matter
on a divided surface : it is as the square of the quantity of matter :
it is as the square of the interval which the accumulation can pass : it
is directly as the attractive force of the free action, all other things
remaining, in each case, the same: it is as the momentum with which
the explosion pervades the metal*.
7. ON THE EMISSION OF LIGHT DURING THE COMPRESSION
OF GASES.
When certain gases have been suddenly compressed, the evolution
* Page 97.
VOL. I. FEB. 1831. 2 C
382 Foreign and Miscellaneous Intelligence.
of light has been observed ; at first this was supposed to be the case
with all gases ; but M. Soissy, of Lyons, stated, that it happened only
with oxygen, air, and chlorine, a result which has been confirmed by
M. Thenard. The latter philosopher, on reflecting that the pistons
used had been greased, thought the light might perhaps be due to
the formation of a little water, or muriatic acid, in these cases ; and
therefore repeated the experiments with pistons moistened only with
water, and then found that no light was evolved.
He then made other experiments on the inflammation of various
substances in compressed oxygen, chlorine, &c. We are constrained
to omit the detail of these, but the following are the conclusions to
the paper: — 1. No gas becomes luminous of itself by pressure
exerted in the ordinary manner in cylinders by pistons. 2. The
highest pressure which can be given by the hand to gas in a tube of
glass raises the temperature much above 400° F. Powders which are
not decomposed at this temperature explode instantly in azote, hydro-
gen or carbonic acid gas, suddenly compressed. 3. Paper and wood
inflame in oxygen suddenly compressed, and oiled paper inflames in
the same manner in chlorine. 4. If the gases be compressed more
forcibly and suddenly, they would doubtless attain a much higher
temperature ; but it is not probable that they would of themselves
become luminous, except at very high temperatures*.
8. ON OXAMIDE, A SUBSTANCE WHICH APPROXIMATES TO
SOME ANIMAL BODIES. — (M. DumasJ)
This substance is produced whenever oxalate of ammonia is distilled,
and the name oxamide, or oxalamide, is given to it provisionally,
as indicating that it is formed of oxalic acid and ammonia, and by
particular treatment can reproduce these bodies. When acted upon
by potash, it yields 36 per cent, of ammonia, though it contains
none ; by the same treatment it can produce 82 per cent, of oxalic
acid, and yet includes none of that body. These curious properties
associate oxamide with the phenomena which occur when animal
substances are made to yield ammonia by the action of alkalies, and
also with those new observations due to MM. Vauquelin and Gay
Lussac, on the developement of oxalic acid, when organic matters
are acted upon by potassa.
When oxalate of ammonia is distilled, it first loses water ; the
crystals become opaque ; then, where close to the heat, fuse, boil,
are decomposed, and disappear without any change occurring in the
more distant parts of the mass. Ultimately, a little carbon remains,
but nearly the whole has been volatilized. The water which has
passed over into the receiver contains a flocculent substance ; a thick
deposit of a dull white matter also lines the neck of the retort ; both
these are oxamide. To isolate it, the whole is diffused in water,
filtered, and washed, the peculiar substance remains in the filter.
100 parts of the oxalate of ammonia yield 4 or 5 of oxamide; the
* Ann. de Chimie, xliv., 181 •
Chemical Science. 383
other products are ammonia, water, carbonate of ammonia, carbonic
acid, oxide of carbon, and cyanogen.
Oxamide occurs in imperfectly crystallized plates, or as a granu-
lated powder. When well washed and pulverized, it is a dirty white
powder, looking like uric acid, having no taste or odour, and not
affecting test papers. Heated carefully in an open tube, it vola-
tilizes ; heated in a retort, part sublimes, whilst part is decomposed,
yielding cyanogen and a very bulky, light charcoal remains. It is
scarcely soluble at common temperatures ; a saturated solution at
212° F. deposits confused crystalline flocculi of the unaltered sub-
stance.
As oxamide is an azoted substance, the ratio of the azote and
carbon to each other was first ascertained by combustion with oxide
of copper in a glass tube. In this mode of analysis, M. Dumas
points out the necessity of collecting the whole of the gas evolved,
and ascertaining its composition. Portions of the gas often differ
from each other ; and if the composition of the whole be deduced
from these portions, great errors may occur. In experiments on
the oxamide, two volumes of carbonic acid were produced for each
one of azote, so that the carbon and the azote are in the same pro-
portion as in cyanogen; 100 parts of oxamide gave 26.95 carbon,
and 31.67 azote.
When oxamide was heated with great excess of concentrated
sulphuric acid, it yielded a mixture of carbonic acid and of carbonic
oxide gases in exactly equal volumes ; no cyanogen was formed ; this
is precisely what takes place with oxalic acid. When the sulphuric
acid was diluted and saturated with potash, much ammonia was
evolved, so that a sulphate of ammonia had been formed. In this
way, therefore, oxamide is resolved into ammonia, carbonic oxide,
and carbonic acid.
When oxamide was heated for some time with strong solution of
potassa in great excess, much ammonia was disengaged. The
potash, afterwards neutralized by nitric acid, was found to contain
oxalate of potassa, so that potassa evolves oxalic acid and ammonia
from oxamide, and those substances only.
These results created a suspicion, that oxamide was to oxalate of
ammonia what pyrophosphoric acid is to the ordinary phosphoric acid.
The substance, therefore, was compared to oxalate of ammonia, sup-
posed to be dry, both by theory and experiment. The carbon is to
the azote as 2 proportionals to 1 in both compounds; but 100 parts of
oxamide contain 26.95 of carbon, and 31.67 of azote, whilst 100
parts of dry oxalate of ammonia contain only 2:2.6 of carbon, and
26.6 of azote. When 100 parts of oxamide were converted by
potash and sulphuric acid into the elements of oxalate of ammonia,
they gave products amounting to 120 parts, i. e., 26.95 carbon,
31.67 azote, 54.70 oxygen, and 6.3 hydrogen — 119. 62. Now, the
sulphuric acid and the" potash could neither of them give carbon or
nitrogen, but might communicate oxygen and hydrogen from the
water present with them: withdrawing 19,62 of these elements in the
384 Foreign and Miscellaneous Intelligence.
proportion to form water, there remains the following composition
as nearly as may be : —
4 vols. carbon 27.08
2 — azote 32.02
2 — oxygen 36.36
4 — hydrogen 4.54
100.
Oxamide may, therefore, be considered at pleasure as a compound
of cyanogen and water ; or as a compound of deutoxide of azote,
and bicarburetted hydrogen ; or as a compound of oxide of carbon
and a hydruret of azote, different to ammonia. Whichever way it
be viewed, if 2 volumes of vapour of water are added to it, dry
oxalate of ammonia is produced ; and it is in this way, apparently,
that sulphuric acid and potassa act.
In conclusion M. Dulong remarks, that many animal matters, as
albumen, gelatine, fibrine, &c., act with potassa as oxamide does.
Uric acid approximates to it : hippuric acid also resembles it. All
these bodies have properties in common with it so characteristic, that
M. Dulong has been induced to commence an experimental com-
parison of them with this new substance *.
9. PREPARATION OF NITROGEN. — (Professor Emmett.)
When zinc is dipped into fused nitrate of ammonia, it is instantly
oxidized and dissolved, and nitrogen and ammoniacal gases are
evolved. The zinc disappears with as much rapidity as when ex-
posed to the strongest mineral acids ; and, at the same time, so com-
pletely sustains the requisite temperature, that it becomes unnecessary
to continue the application of heat after the action commences. The
heat required is 280° or 300°, but a small piece of zinc soon elevates
it to 540°. No nitrous or nitric oxide could be detected in the
evolved gas, and therefore Professor Emmett recommends the
operation as one well fitted to supply nitrogen gas.
A tubulated retort is to be partly filled with the nitrate of am-
monia, and a cork fitted to the tubulature. Through this cork is to
pass freely either a knitting-needle or an iron wire, holding, by means
of a hook, the coil of zinc. As soon as the salt has entered into
fusion, the knitting-needle must be pushed down far enough to
place the zinc in contact with the nitrate. This arrangement is not
only convenient but necessary ; for if the zinc be thrown at once
into the fused salt, the action will prove too violent and unmanage-
able ; whereas, when contact is not constantly maintained, there is a
strong tendency towards a vacuum in the retort, which would
endanger its safety. By the process here recommended, there is no
liability to accident, and the quantity of nitrogen may be easily
* Ann. de Chimie, xliv, 113,
Chemical Science. 385
fegulated, by raising or lowering tlic zinc. Every grain of the
metal furnishes nearly a cubic inch of the gas, while the ammonia,
which also escapes, becomes wholly condensed as soon as it enters
into the water of the pneumatic cistern *.
10. ACTION OF MIXED NITRATE AND MURIATE OF AMMONIA
ON GLASS.
When equal parts of these salts are mixed and fused between two
watch-glasses, the under glass becomes corroded nearly to one-half
of its thickness, and the eft'ect even extends to the cover. The heat
of a spirit-lamp is quite sufficient for this purpose. Here, without
water, or even perfect fusion, the alkali is entirely removed, and the
silex left, forming a snow-white opaque substance, so soft as to admit
of being cut through with the point of a needle or knife : green glass
is not so easily affected, owing to its greater hardness and the
absence of lead. The fused nitrate alone, if confined between watch-
glasses, also produces slight corrosion, but the effect is so remark-
able when the nitro-muriate is employed, that a person operating
upon an unknown mineral, and ignorant of this property, would
be induced to attribute the result to the presence of fluoric acid.
Indeed, when we consider that the effect appears to depend upon
the liberation of nitro-muriatic acid, or perhaps even to highly con-
centrated nitric acid alone, it does not seem improbable that similar
cases have often occurred by the common mode of analysing ; and
this opinion is further strengthened by the fact, that some minerals,
as the chondrodite, appear to have furnished fluoric acid to one
operator and not to another f.
11. PULVERIZATION OF PHOSPHORUS. — (CasasecaJ)
If phosphorus be put with alcohol into a bottle, and shaken for
some time, it may be obtained in powder of the utmost tenuity,
which, when diffused through the alcohol, appears as if it consisted
of a multitude of minute crystals.
12. INFLAMMATION OF PHOSPHORUS BY CHARCOAL.
Dr. Bache, of Philadelphia, states, that, at the temperature of 60° R,
or upwards, carbon in the form of animal charcoal, or lampblack,
causes the inflammation of a stick of phosphorus powdered with it ;
the effect takes place either in the open air, or in a close receiver of a
moderate size {.
13. PREPARATION OF BI-CARBONATE OF SODA.
The following method of preparing this salt, in the large way, is
described by Mr. F. R. Smith, of Philadelphia. The ordinary crys-
* Silliman's Journal, xviii. p. 259. f Ibid, xviii. p. 258.
J Sillimaii's Jouroal, xviii, p. 373,
386 Foreign and Miscellaneous Intelligence.
tals of carbonate of soda are placed in a box made on purpose, and
are surrounded by carbonic acid gas under pressure. The salt
absorbs the gas, and, as the bi-carbonate requires but little water,
much of that contained in the crystals of the original carbonate drip
away in the form of a solution. When gas ceases to be absorbed,
the salt is taken out, and dried at a moderate temperature.
Upon examination, after the absorption of gas has ceased, the
portions of salt are found in their original form, but porous and
friable, and the fracture without lustre. Each consists of an aggre-
gation of crystalline grains as white as snow, and scarcely alkaline
to the taste. In this way all the trouble of solution, evaporation, &c.
involved by the ordinary process, is obviated. The production of
gas should be continued for a sufficient time, and the subsequent
drying of the salt should be at a moderate temperature, or else por-
tions of carbonate may remain.
When a portion of salt thus prepared was washed with a little
water, to remove any carbonate, then dried and analysed, it proved
to be, not sesqui-carbonate, but true bi-carbonate. M. Boullay has
repeated the process on a large scale, and obtained exactly similar
results*.
14. ROCK SALT IN ARMENIA.
Armenia was incorporated with Russia in 1828, by the treaty of
Tourkmantchai, made with Persia. The salt is found in a mountain
two leagues and a half from Nakchitchevane, situated on an exten-
sive plain extending along the left bank of the Araxes. The moun-
tain is seven leagues and a half in circumference, and, from the ap-
pearance of very ancient works, has evidently yielded salt for many
ages. These remains consist of enormous horizontal galleries, sup-
ported by pillars of salt; and, according to the traditions of the
people, many mines have been abandoned from the difficulties of
working them, occasioned by the depth of the strata and frequent
inundations. The Persian government, for the last fifteen years of
its time, let them for a sum equal to 16,000 francs annually.
The salt is worked by gunpowder ; the works are wrought by the
irmabitants of a small neighbouring village, consisting of Armenians
and Tartars, from three to twenty persons being required at a time.
The Russian government has let the works, since March, 1829, for
a year, for a sum equal to 16,000 francs t.
15. PREPARATION OF LITHIA. — (Quesneville, jils.}
One part of triphane is pulverised in water, mixed intimately with
two parts of pulverised litharge, put into a crucible and heated to
whiteness. In a quarter of an hour the whole is liquid ; it is to be
* Journ.de Pharm. 1830,~p. 118.
f Revue Ency. xlviii, p. 504.
Chemical Science. 387
poured out, finely pulverised, acted upon by nitric acid, and the un-
dissolved silica separated. The lead is then to be precipitated by
sulphuric acid, and the liquid evaporated to dryness, to drive off the
nitric acid ; the residue is to be dissolved in water, the alumina and
metallic oxides precipitated by ammonia, the lime and magnesia by
carbonate of ammonia, and the filtered liquid evaporated to dryness.
The residue is to be strongly heated in a porcelain (not platina)
crucible ; what remains dissolved in water ; the sulphuric acid preci-
pitated by baryta water ; and the new liquid, being filtered and eva-
porated, gives pure lithia.
M. Quesneville very strongly recommends the use of nitrate of
lead in the analysis of alkaline minerals, according to M. Berthier's
proposal*.
16. ON THE SUBMURIATES OF IRON, AND OTHER SUBSALTS.
(Mr. Phillips.)
Whilst dissolving moist precipitated peroxide of iron in muriatic
acid, Mr. Phillips observed that much more oxide was taken up than
he had expected, and, after repeated additions, he obtained a very
deep red-coloured solution, having little of the well-known chalybeate
taste, and of the s. g. of 1.017 ; it was not decomposed by the addi-
tion of water, or by heat, unless evaporated to dryness: alkalies
decomposed it. 'Ferroprussiate of potash gave a dark brown-green
precipitate. When more oxide was added, the excess, or a portion
of it, combined with the submuriate already formed, and the acid and
oxide were totally precipitated, forming another but an insoluble sub-
muriate. Even the addition of muriatic acid caused a partial decom-
position of the soluble submuriate, and a precipitation occurred : this
happens with no other binary salt.
Being analysed, the soluble submuriate gave 37 muriatic acid and
382 of peroxide of iron, equal to one atom of muriatic acid and 9J
of peroxide. Mr. Phillips is inclined to consider 1 : 10 as the true
proportion.
Except the subacetate of lead, this is the only subsalt so largely
soluble in water ; probably, the only one which contains so small an
atomic proportion of acid ; the only one decomposed by addition of
either acid or base : and the last mentioned point shows that there
are two other submuriates of iron differing from this one, by insolu-
bility in water.
Mr. Phillips has also analysed the submuriate of antimony, or
powder of Algaroth. It consists of protoxide of antimony 92.45,
muriatic acid 7.8 ; or 9 atoms and 1.
Subnitrate of bismuth was also analysed, and proved to consist of
81.92 oxide of bismuth, and 18.36 nitric acid ; or 3 atoms and 1.
Submuriate, or magistery of bismuth, being analysed, gave 87
oxide of bismuth, and 13.6 muriatic acid; or 3 atoms and 1. Ac
* Journ. de Pharm. 1830, p. 1196.
388 Foreign and Miscellaneous Intelligence.
cording to Dr. Thomson, the carbonate of bismuth is a triscarbonate,
similar in constitution to the subnitrate and submuriate above.
Upon decomposing the subnitrate and submuriate of bismuth by
alkali, they yield oxide of bismuth ; that, in the first case, is always
yellow, but in the second it varies much in colour, being frequently
greyish-black and even deep bluish-black. The cause of these varia-
tions has not been discovered, nor even the circumstances which
ensure a dark coloured preparation. It is not due to sulphu-
retted hydrogen or other impurities, nor to difference of composition.
When the black oxide was heated on platina foil, it lost neither
weight nor colour ; but, being melted, it became yellow : the cause
is probably, therefore, in some difference of aggregation ; and may
in that respect be analogous to the differences of colour, which can
be induced, by various means, on chloride of silver *.
17. ON THE REACTION OP PERSALTS OF IRON AND NEUTRAL
CARBONATES.
M. Soubeiran has experimentally investigated this action, and arrived
at the following conclusions : — i. When salts of the peroxide of iron
are decomposed by neutral carbonates, they yield a carbonate of the
peroxide equally neutral : this carbonate is soon destroyed to pro-
duce a double salt, formed of the neutral alkaline sulphate and the
subsulphate of iron : this new salt is also easily decomposed, and
yields a new sulphate of iron heretofore unknown, and containing
thrice as much base as the neutral salt : a feeble alkali in excess
precipitates another subsalt, which chemists have not before noticed,
and which is a true double salt, composed of the subsulphate of iron
and hydrated oxide of iron. ii. That the aperient saffron of Mars
is a hydrate of the peroxide of iron, containing 3 atoms of water
mixed with variable and accidental quantities of sesqui-subcarbonate
of iron, and sometimes neutral carbonate of iron f.
18. ON THE RELATIVE ACTION OF DILUTED SULPHURIC AciD AND
ZINC.— (M. A. de la Rive.)
Whilst engaged in experiments on the construction of the voltaic
pile, M. de la Rive was struck more particularly with a fact which
has often been observed by chemists, but has never received its proper
explanation. If zinc, purified by distillation, be plunged into dilute
sulphuric acid, it is scarcely attacked, especially at first ; it produces
but a small quantity of bubbles of hydrogen, and these succeed each
other very slowly ; but zinc of commerce, placed in the same cir-
cumstances, produces an enormous quantity of hydrogen, with an
effervescence and vivacity well known to those who have prepared
this gas.
* Phil. Mag. N. S. viii. p. 406.
f Journ. de Pbarra. 1830, p. 535.
Chemical Science. 389
In examining the influential circumstances of this action, two ap-
peared to have predominating power ; the degree of dilution of
the acid, and the state of the metal. These were estimated by the
quantity of gas evolved from given surfaces of zinc in a given time ;
and a convenient little apparatus for that purpose was used, which
allowed of the quick repetition of the experiments, and furnished
accurate results as to the volumes of gas produced.
Six mixtures of acid and water were used. In the following table,
the first column gives the number by which any mixture is distin-
guished in the future experiments, the second expresses the specific
gravity, and the third the quantity of sulphuric acid per cent
1 . . 1.137 . . 20.20
2 . . 1.182 . . 25-64
3 . . 1.215 . . 29.85
4 . . 1.258 . . 35.28
5 . . 1.326 . . 43.25
6 . . 1.532 . . 64.20
When the different kinds of zinc were immersed in these acids, it
was with the exposure of certain measured and equal surfaces : thus,
in the following table, pieces of zinc, each having 200 square mille-
metres of surface, were left in the respective acid, until each had
evolved 300 cubic millemetres of hydrogen gas ; and the time occu-
pied, which constitutes the table, of course expresses inversely the
facility with which the acid and zinc evolved gas.
Acid .... No. 1. No. 2. No. 3. No. 4. No. 5. No. 6.
Zinc of commerce 0'.6" 0'.3" 0'.2" 0'.3" 0'.4" 0/9"
Distilled zinc . 3'.30" 1'.50" 0'.30" 0'.26" 0'.24" 1/30"
These experiments were all made with liquid at the same tempera-
ture— L e., between 10° and 12° C., but the temperature rose, and
the more the stronger the action ; thus, with the acid No. 3 it rose
about 5° C., or 9° E, in 15 minutes. Another fact to be noticed is,
that the action was very slow in all at first, but afterwards rose slowly
with the pure zinc, but rapidly with that of commerce : the latter
generally attained its maximum action in 10 minutes, the former
required several hours for that effect. It appears, also, that the acid
No. 3 is that which acts most energetically upon ordinary zinc ; the
Nos. 2, 4, and 5 differ somewhat from it; Nos. 1 and 6 much. No.
3 contains 30 per cent, of sulphuric acid ; and it may be said gene-
rally that, for the evolution of hydrogen most rapidly from ordinary
zinc, the diluted acid should contain not less than 25, nor more than
50 per cent, of oil of vitriol.
The action of the acids on pure zinc, it may be observed, does not
follow the same order as on ordinary zinc.
With regard to the cause of the difference between pure and ordi-
nary zinc, it might at first be supposed to be due to a degree of open-
ness or porosity in the latter, but it was found that each had the same
390 Foreign and Miscellaneous Intelligence.
specific gravity, namely 7.2, and the differences were the same also,
when each "were reduced to filings.
Concluding, therefore, that it was more probably due to the pre-
sence of heterogeneous substances in the ordinary zinc, certain
mixtures were made of pure zinc and other metals, and four alloys
prepared ; — the first, contained a tenth of iron filings, added when
the distilled zinc was in fusion ; the second, a tenth of tin ; the third,
a tenth of lead ; and the fourth, a tenth of copper. These zincs were
then tried as the former were, the same quantities of surface being
exposed and of gas collected. The following are the results : —
Acid . No. 1, 10° C. No. 2, 10° C. No. 3, 15° C.
Distilled zinc 3'.27" 1'.50" 0.30"
Tin zinc . 0'.24" 0'.12'' 0.12"
Lead zinc . 0'.12" 0'.9" 0.10"
Copper zinc 0'.4" to 6 0'.6" , 0.3" to 4
Iron zinc . 0'.4" 0/3" 0.2'' to 1
Common zinc 0'.4" 0'.3" 0.2" to 1.
Generally in these experiments the action was at first slow, and
then increased more or less rapidly, according to the nature of the
alloy, until it had obtained its maximum, which is the rate expressed
usually by the time in the table ; the copper zinc formed an exception
— its action was most rapid at first, and gradually became slower,
from the formation of a black crust of oxide, &c. upon it ; this being
removed, the rapidity of action was restored. The iron zinc, it may
be observed, was acted upon as rapidly as the ordinary zinc of com-
merce.
The circumstances accompanying the phenomena in question are
such as to induce a persuasion on the mind that the whole is due to
electro-chemical action. The first circumstance is the powerful influ-
ence of a heterogeneous metal, mixed with pure zinc, to facilitate
the decomposition of water and disengage hydrogen. The second
is, that the diluted acid which is most powerful in exciting this action
is that which is the best conductor of electricity. By a very careful
set of experiments, made with the galvanometer, it was found that the
acids 3 and 4, and especially 3, were much better conductors than any
other of the mixtures. Former experiments had shown that concen-
trated sulphuric acid was a worse conductor than diluted ; but now it
was proved that acid, containing between 30 and 50 per cent, of oil
of vitriol, was a better conductor than if either stronger or weaker ;
and it is precisely such acid which evolves hydrogen most rapidly
from ordinary zinc.
As a further illustration of the influence of voltaic action on zinc
dissolving in acid, — if a piece of distilled zinc be dissolved in the
diluted acid, it requires a certain time to produce a certain quan-
tity of gas ; if a platina wire, immersed in the acid, be made to
touch the zinc, it, of course, immediately gives out hydrogen ; and the
whole quantity of gas from the two metals, under these circum-
stances, is twice or thrice what it was before. If the platina wire
Chemical Science. 391
be rolled round the zinc, or if the latter be studded with pieces of
platina, then the quantity of gas evolved principally from the platina
is much more than from the zinc alone.
Now, tlu! action upon the alloyed zinc appears to be quite analo-
gous to the action upon the voltaic circle formed above by the zinc and
platina. The small chemical action which takes place on pure zinc
determines an electric current between each molecule of zinc, and
the molecule of other metal in contact with it. These currents de-
compose the water which they traverse, according to the well-known
laws of voltaic decomposition — evolving the hydrogen upon the
heterogeneous molecule, which is negative in all the alloys and com-
binations mentioned, and carrying the oxygen to the zinc, which is
positive, and, combining with it, it forms first an oxide and then a sul-
phate, which dissolves. This decomposition of water, and conse-
quently the quantity of hydrogen evolved, will be greater as the minute
currents of electricity are stronger, and these will be stronger as the
acid increases in conducting power. Now it has been found experi-
mentally that the acid mixture which conducts best, evolves most gas
in a given time.
The decomposition of water should, in this mode of viewing the
question, also increase with the difference between the oxidability
of the zinc and the other metal. The iron zinc has, however, in these
experiments, surpassed the copper zinc, although the two latter metals
form a more powerful voltaic arrangement ; but then two circum-
stances affect the result. The energy of the current depends much
upon the facility with which it can pass from the negative metal to
the fluid in contact ; and it has been ascertained that this passage takes
place to the acid from the iron, much more readily than from the cop-
per. On the other hand, the copper zinc exerts always a stronger action
at first than afterwards — stronger, indeed, sometimes than iron zinc ;
but then the intensity of its voltaic action causes decomposition of
part of the zinc salt in solution, oxide is deposited upon the particles
of copper, and, forming the crust before spoken of, diminishes very
importantly its voltaic action. The same effect occurs with distilled
zinc, furnished with platina wires.
From all these considerations, there appears to be no reason to
doubt that the striking difference between pure zinc and zinc of com-
merce, when put into dilute sulphuric acid, is due to the presence of
heterogeneous substances in the latter. By analysis, ordinary zinc
is usually found to contain traces of copper, tin, lead, and rather
more than a hundredth of iron ; and, on extending the experiments
with the zinc alloys, it was found that 2 per cent, of iron filings,
added to distilled zinc, was sufficient to render it as active in acid as
ordinary zinc.
The elevation of temperature resulting from the chemical action of
the liquid upon these zincs, and which increases with the vivacity of
the action, is very probably due to the heating power of these nume-
rous electric currents. These currents are more powerful when most
gas is disengaged ; the heating power of the voltaic current is well
392 Foreign and Miscellaneous Intelligence.
known, and, indeed, all circumstances accord in pointing out this as
the principal source of the heat evolved.
A striking confirmation of the explanation now given of these
exalted effects of common and alloyed zinc, is derived from an in-
vestigation of their power of forming voltaic combinations of more
or less intensity. Being combined two and two, and examined by
the galvanometer, it was found that the order was as follows : dis-
tilled zinc, lead zinc, tin zinc, iron zinc, zinc of commerce, and copper
zinc: thus arranged, the most positive are first, or each is positive
with those following it, negative with those preceding it. When
combined into voltaic pairs with copper, distilled zinc, lead zinc, and
tin zinc, were most powerful, then zinc of commerce, and iron zinc ;
copper zinc was last, and very inferior to the rest. It appears,
therefore, that the kinds of zinc which exhibit least action in diluted
sulphuric acid are those which form the most powerful voltaic com-
binations with such metals as copper, silver, platina, &c., and this
might be expected : for the disengagement of hydrogen on the sur-
faces of the zincs does not arise from a direct chemical action, but
from the action of the minute electric currents established between
the molecules of the zinc and the heterogeneous metal present in it ;
whereas the current, sensible to the galvanometer, is produced by
the direct action of the acid on the positive element of the pair of
plates used. This direct action is stronger on the pure zinc than on
the zinc mixed with less oxidable substances ; and the less these
heterogeneous substances are oxidable, the less positive should the
zinc be*, This distinction will probably explain many apparent
* Is not the diminished power of the alloys in forming voltaic combination
with more negative metals due rather to the circumstance of their finding the
negative element ready for them, under more favourable circumstances, than that
which, in the form of a copper plate or platina wire, is purposely added by the ex-
perimenter ; than to any material diminution of the direct chemical action ? The
heterogeneous metal originally in the zinc forms a voltaic combination with it,
having great extent of surface, because of itsjninute division, in excellent contact,
and at the smallest possible distance ; and therefore must divert the course of
much of the electricity which in pure zinc finds its exit into the fluid only by the
negative element purposely added.
We refer our readers to a similar effect to the above remarked by Messrs. Stodart
and Faraday, in their paper on alloys of steel, and which they also referred to voltaic
action. ' If two pieces, one of steel, and one steel alloyed with platina, be im-
mersed in weak sulphuric acid, the alloy will be immediately acted upon with
great rapidity, and the evolution of much gas, and will shortly be dissolved, whilst
the steel will be scarcely at all affected. In this case it is hardly possible to com-
pare the strength of the two actions. If the gas be collected from the alloy, and
from the steel, for equal intervals of time, the first portion will surpass the second
some hundreds of times. A very small quantity of platina alloyed with steel con-
fers this property upon it; ?i5 increased the action considerably; with 5i^ and
j£5 it was powerful; with 10 per cent, it acted, but not with much power; with
50 per cent, it was about equal to steel alone.' These alloys were very perfect ;
that which was most active in acids did not render a platina wire more negative
than ordinary steel, and the cause, as was suggested at the time by Sir H. Davy,
is referred to electrical action, the view taken being described at length in the
paper in the Phil. Trans, for 1822, p. 262.
Chemical Science. 393
anomalies, and serves to show how difficult it is to judge of the true
intensity of chemical action exerted upon a substance by liquids in
contact with it *.
19. CRYSTALLIZATION OF BISMUTH.
M. Quesneville, fiU, says, that by the following process, magnificent
crystals of this metal may be obtained. Bismuth is to be fused in a
crucible, fragments of nitre added from time to time, and the heat raised
so as to decompose the nitre, and the whole mixed by agitation. Con-
tinuing the heat and the addition of nitre in this way for some hours,
a time arrives when a little of the metal agitated in the air exhibits
magnificent green and golden-yellow colours, which it retains when
cold. If the metal displays only rose, violet, or indigo colours, and
when cold is a white mass without colour, it is certain that good
crystallization will not occur. When the metal is in right condition,
it is to be poured into a ladle previously heated ; and to prevent the
surface cooling faster than the bottom, it should be covered, or a hot
shovel held near it. The cooling should not be too slow, for then
the metal crystallizes layer by layer, and offers no fine forms ; it is
necessary that the cooling be rather sudden. When the upper crust
has formed, it should be pierced by a hot coal, and not by percus-
sion (which disturbs the crystals), and the remaining liquid metal
decanted. In about half an hour longer the rest of the crust may
be broken, and the interior will be found magnificently crystallized,
the crystals being more beautiful as the above conditions have been
more carefully followed f.
20. ON DISCOLOURED CHLORIDE OF SILVER. — (M. Cavalier.')
Chloride of silver blackened by sun-light is perfectly well known.
M. Cavalier obtains it in a similar state by dissolving the recent
chloride in ammonia, and passing chlorine gas into the solution;
the usual decomposition of ammonia with elevation of temperature,
evolution of azote, &c., takes place, and ultimately the liquid becomes
turbid, and the chloride of silver appears first as a grey, and then,
when the ammonia is entirely decomposed, as a violet precipitate.
This precipitate dissolves entirely in ammonia, and is precipitated
in a perfectly white state by pure nitric acid. If 20 grains of it be
decomposed by zinc in dilute sulphuric acid, it yields 15 grains of
silver, exactly the quantity yielded by similar treatment from 20 grains
of white chloride. Hence the difference of the chloride in these two
states cannot be referred to difference of composition, but solely to
some variation in molecular arrangement J.
* Bib. Univ. 1830, p. 391. t Jour, de Pharmacie, 1830, p. 534.
J Jour, de Pharmacie, 1830, p. 553.
304 Foreign and Miscellaneous Intelligence.
21. COMPOSITION OF FULMINATING GOLD.
M. Dumas lias analysed tlie fulminating gold prepared by precipitat-
ing solution of chloride of gold by ammonia, the process adopted
being that of burning it with oxide of copper. He found 100 parts
to yield —
Metallic gold . . 73.00
Nitrogen . . . 9.88
Chlorine . . . 4.50
87.38
by further experiment and reasoning, it was deduced that there were
besides, 2.2 parts of hydrogen and 10.42 of oxygen. These elements
are considered as being thus arranged : — gold 73 ; azote 5 ; am-
monia 6; chlorine 4.5: water 11.5; and the proportions of the
ultimate elements are given as 6 atoms of gold ; 12 of azote ; 2 of
chlorine ; 42 of hydrogen ; and 9 of oxygen. It is finally viewed
as a compound of 2 atoms of ammoniacal azoturet of gold, and
1 atom of ammoniacal subchloride of gold, with enough water to
convert the azote into ammonia, and the gold into oxide of gold.
Oxide of gold digested in ammonia forms another fulminating
compound. This compound analysed gave 2 atoms of gold ; 4 of
azote ; 12 of hydrogen ; 3 of oxygen *.
22. WHEWELL'S WRITTEN NOMENCLATURE FOR CHEMICAL
COMPOUNDS.
Extract from Professor Whewell's Essay on Mineralogical Classifi-
cation and Nomenclature : —
' Professor Whewell's mode of designating the combinations of
chemical elements is different from that of Berzelius and of Beudant,
but the alteration seems to be absolutely necessary. According to
their method, the first combination of elements into binary compounds
is indicated by writing the symbols together, without any connecting
sign ; as if they were algebraically multiplied : and the number of
atoms of each element is denoted by figures, written as indices
of powers generally are. Thus, C -f- 2 c they would represent by
C c 2, and 3 C ' + 2 S by C3 S2, &c. Now this notation is in the high-
est degree inconvenient, besides violating all symmetry and analogy.'
For when the substance is indicated by 2 A S + C3 S2, there is no
longer any obvious identity with 2A + 3C -f- 4 S, which is the real
result of the analysis.
* Ann, de Chimie, xliv. p. 1G7.
Chemical Science. 395
Substance. Benelius's Notation. Whewell's Notation.
Phosphate of Lime C8 Pa 3 C + 2 P
Felspar . . KS8 + 3 A S8 (K + 3 S) + 3 (A + 3 S)
Alum KS8 + 2 ASa + 48 • Aq 2 • (A + 3 S) + K + 2S + 48 : A?.
Coefficients are, in all cases, used instead of indices.
23. PARA-TARTARIC ACID.
M. Dulong read to the academy a letter from M. Berzelius, relative
to numerous chemical compounds, which being similar in the nature
and proportion of their elements, yet differ in property from each
other. M. Berzelius had been particularly engaged with the acid
found in tartar by M. Gay Lussac, which has been called Vosges
acid (Thannic acid.) He shows that this acid, though differing from
ordinary tartaric acid in many properties, has exactly the same com-
position.
Similar difference in properties without difference of composition
is found in phosphoric and pyro-phosphoric acid ; in stannic acid or
deutoxide of tin, obtained from tin by nitric acid, or obtained from
Libavius liquor by precipitation.
To associate and yet distinguish substances under tliese peculiar
circumstances, M. Berzelius proposes to prefix the Greek term para
to the name of that body which occurs most rarely, or which is
obtained with the most difficulty, thus: — Phosphoric acid, and para-
phosphoric acid ; tartaric acid, and para-tartaric acid ; stannic acid,
and para- stannic acid, &c.*
24. PREPARATION OF PIPERIN, BY MR. CLEMSON.
The pepper should be ground and digested in alcohol of specific
gravity 0.832, or 0.817 at a smart distilling heat; an alembic, with its
water bath, is at once convenient and economical; the whole should
be agitated from time to time, and the fluid changed if necessary. I
know of no better indication of the entire extraction of the piperin,
than the want of taste in the marc or insoluble residue ; although
acridity (as has been represented) is by no means a property of piperin.
The alcoholic solutions being united, should be reduced over a water
bath. The distillation ended, there will be found in the bottom of the
alembic a deposit composed of a great deal of piperin, and a black
acrid resino-oleaginous substance ; the separation of this latter com-
pound from the piperin is difficult in the extreme ; so much so, that
I have seldom or never seen the preparation free from acridity, which
not only destroys, but produces a contrary effect to that desired,
when employed as a remedy. The greater part of this viscous oil
may be separated by cold alcohol, piperin being much less soluble in
* Jour, de Pharmacie, 1830, p, 622.
396 Foreign and Miscellaneous Intelligence.
this menstruum, when cold, than when warm, and much less than the
oil. The latter portion may be entirely separated by the addition of
a little lime to the warm solution of piperin with the oil, and leaving
it to crystallize in the same vase ; the piperin, when cold, may be
separated at leisure : by re-dissolving the crystals thus procured,
adding a little animal charcoal, and filtering when hot, a solution
will be obtained, which, upon cooling, will afford crystals of a canary
white, regular and free from acridity. Mr. Pontel has advised the use
of caustic potash, and the effect is certainly very marked. The
solution should be weak, for caustic potash has a tendency to alter
the nature of the substance, and instead of procuring piperin, I once
formed a compound that very much resembled soap, and all subse-
?uent attempts to procure the substance in crystals failed ; moreover,
have always observed, that those crystals obtained by the aid of
potassa had more or less of a reddish tinge, and were very brittle.
Piperin, when pure, crystallizes in right square prisms, occasionally
presenting an anomaly, the crystals, particularly those obtained
through the means of potassa, being hollow, or containing an interior
decrement, the four vertical sides being entire, and showing the form
of the crystal ; they are insoluble in water, soluble in cold alcohol,
and more so when warm ; insoluble in acetic or other acids. Piperin
has been employed latterly in Italy as a febrifuge*.
25. ON SALICINE BY MM. PELOUZE AND JULES GAY LUSSAC.
Salicine, when pure, forms white crystalline prismatic needles. It
has a bitter taste and somewhat of the odour of willow bark. One
hundred parts of water dissolve 5.6 parts of salicine at 67° F. : at
212° F. it appears to dissolve in any proportion. It is equally soluble
in alcohol, but ether and oil of turpentine take up no portion of it.
Concentrated sulphuric acid gives it a fine red colour, like that of
bichromate of potassa. Muriatic and nitric acids dissolve it without
producing any colour. It is not precipitated from its solution by
infusion of nut-galls, gelatine, neutral or subacetate of lead, alum, or
emetic tartar. It does not saturate lime-water when boiled with it
in excess : it does not dissolve oxide of lead : it fuses a little above
212° F., losing no water, and crystallizes upon cooling. If the heat
be rather higher, it acquires a lemon-yellow colour, and becomes,
when cold, brittle as resin.
Salicine, burnt by means of oxide of copper, yields a gas entirely
absorbable by potash. The mean of two analyses gave the following
as its composition : —
Carbon . . 55.491 = 2.028 proportions.
Hydrogen . 8.184 = 2.004 „
Oxygen . . 36.325 = 1.000 „
Its composition may, therefore, be represented by two volumes of
olefiant gas, and one volume of oxygen f.
* Sillhimu's Jour, xviii. p. 253. f Ann, de Chimie, xliv. p. 220.
Chemical Science. 397
26. PREPARATION OP SALICENE.
The following is the process recommended for this purpose by
M. Peschier. The bark of the willow is to be dried, crushed, boiled
for one or two hours in water, and the liquid separated by a cloth,
and powerful pressure. Subacetate of lead is to be added as long as
precipitation occurs ; the whole filtered ; the clear liquor boiled with
enough carbonate of lime to decompose the excess of acetate of
lead, saturate the acetic acid, and remove the colour. Being left to
settle, the clear liquor is to be decanted, the deposit washed twice or
thrice, the washing liquor added to the former, and the whole evapo-
rated to the consistence of an extract. This extract, whilst hot, is
to be put into bibulous paper, and pressed for some hours ; after
which it is to be digested in alcohol of s. g. 0.847, the fluid filtered
and concentrated, when it will yield crystallized salicene, very white
and pure.
Salicene thus obtained, when administered in doses, of from 15 to
18 grains, in the intervals of intermitting fevers, was found perfectly
effectual in stopping their progress*.
27. NEW KIND OF INDIGO.
The Registro Mercantil of Manilla describes a new kind of indigo
lately discovered in that island. This plant has been long known to
the natives, especially in the provinces of Caramini and D'Albay ;
they gave it the name of payanguit or avanguit, and obtain a
superb blue colour from it. In 1827 it attracted the attention of
Pere Mata, one of the members of the Economical Society of
Samar. He made many experiments upon it, formed it into cakes,
and dyed cotton, linen, and silk goods with it. The colour he ob-
tained was so rich, and so equal to that of indigo, that he sent some
of the cakes and the dyed fabrics to the Society, who directed other
members residing in the same province to repeat Pere Mata's expe-
riments. All obtained most satisfactory results, and they sent many
of the cakes, the leaves, and even the living plants, to Manilla. A
committee of merchants and chemists was appointed to ascertain, by
every kind of trial, whether the colouring matter was identical with
that of indigo, and might be introduced as such into the market at
the same price. The committee reported in the affirmative on these
points, declaring that the payanguit had all the valuable properties
of the plant to which it had been comparedf.
28. CHARRING OF WOOD AT Low TEMPERATURES.
Mr. Phillips has described the following case of the slow decom-
position of wood at low temperatures : —
Mr. Charles May, chemist, of Ampthill, has sent me some speci-
mens of wood, converted into nearly perfect charcoal at a very low
* Ana. de Chim, xliv. p. 418. f Bib, Univ. 1830, p. 223.
VOL. I. FEB. 1831. 2 D
398 Foreign and Miscellaneous Intelligence.
but long-continued heat. The pieces, he informs me, are part of the
bottom of a tub which held about 130 gallons, and which had been
in use in his laboratory about three years and a half, and almost
constantly worked for boiling a weak solution of common salt, gene-
rally with an open steam-pipe, and sometimes, though rarely, with a
coil : the temperature was seldom higher than 216° or 220°/and the
vessel was lined with tin, rolled into sheets, about the sixteenth of
an inch thick, and nailed to the inside ; the joints, however, were not
so good as to prevent the liquid from getting between the metal and
the wood. Mr. May states also that he had long since remarked,
that on making extracts with steam of very moderate pressure, all
the apparent effects of burning might be produced, but that he was
not prepared to find so complete a carbonization of wood by steam :
the vessel was made partly of fir and partly of ash, the former of
which was most perfectly reduced to the state of charcoal*.
29. CHANGE OF COLOUR IN THE WOOD OF CERTAIN TREES.
M. Marcet has experimented upon this point, particularly with the wood
of the alder, which, exposed to air, becomes red or brown. The
change did not take place if, the instant the wood was cut, it was
introduced into a perfect vacuum, or into gases containing no oxygen ;
but, on the contrary, being put into oxygen, the red colour became
more vivid than in the air. If the wood, when cut, was plunged
into water, it always reddened, whatever attempts were made to
exclude oxygen. Some of the wood, which had acquired a yellow
colour, communicated that colour to water, and the water, being
evaporated, left a substance having every character of pure tannin.
M. Marcet concludes, from his experiments, that the colouration of
the alder wood is always due to a degree of oxygenation which
the tannin undergoes immediately upon its exposure to the air or
oxygenf.
30. PRESERVATION OF BLOOD.
Sugar refiners and others are often inconvenienced by the difficulty
of obtaining blood at the time when it is required for use. M. Toursel
has endeavoured, in part, to remove this difficulty, by proposing a
method of preserving this agent for some time without injury. It
consists in putting the blood into bottles or other vessels with very
narrow mouths, and being careful to fill them up to the neck ; a layer
of oil, to the depth of at least half an inch, is then put upon it to cut
off communication with the atmosphere, and the whole is left to
itself. M. Toursel states that he has in this manner preserved blood,
\yith all its physical and chemical qualities, from the 1st of December,
1827, to January, 1829J.
* Phil. Mag. N.S. viii. p. 383. f Bib. UmV, 1830, p. 228.
:j: Journ. do Commerce.
Chemical Science. 399
31. PRESENCE OP MANGANESE IN THE BLOOD. — (Professor Wurzer,
of Marburg.)
In some analyses of human blood, according to Engelhart's method,
by liquid tests, Prof. W. was led to suspect that, besides the usual re-
sults, he had also obtained a small quantity of manganese : not being,
however, quite sure of the correctness of his analyses, he was induced
to repeat them in the following manner : — The blood, which had been
obtained by venesection, on the day before the experiment, was
ignited in an open crucible, the incinerated mass oxidized by nitre,
and then diluted with water ; the residuum was dissolved in muriatic
acid, and the iron precipitated from the solution by succinate of am-
monia. As the precipitate contained also some phosphate of lime,
it was again ignited, and then dissolved in muriatic acid : the phos-
phate of lime was separated from the solution by alcohol, the excess
of the latter expelled by heat, and the iron precipitated by ammonia.
By boiling the filtered liquid with carbonate of soda, the manganese
was precipitated, and then dissolved in nitric acid and again ignited.
In two grammes of the coal was found 0.108 ox. of iron, and 0.034
protox. of manganese*.
32. ON TWO ORES OP TELLURIUM FROM THE ALTAI MOUNTAINS.—
(M. Rose:)
During the journey through Russia and Siberia, which M. Rose, of
Berlin, lately made in the company of MM. Humboldt and Ehrenberg,
he found two ores of tellurium in the silver mines of Sawodinski,
near those of Siranowski, at the river Buchtharma, and as this metal
has hitherto been only found in the gold mines of Transylvania and
in Norway, this discovery is of the greatest interest. We extract the
description of tellurium-silver and tellurium-lead as it is given by
M. Rose in Poggendorf's Annalen.
He first saw these two ores in the Museum of the town of Bar-
noul, near the river Ob ; besides numerous smaller pieces, there were
two large blocks of about a cubic foot each, which, on account of
their malleability and the large quantity of silver they contained,
were considered to be silver-glass, from which they, however, were
found to differ greatly. Tellurium-silver is of granular texture, not
crystallized nor cleavable ; has much metallic lustre, and its colour
is between that of lead and steel : it is malleable, though to a less
degree than silver-glass ; and its specific gravity was found, by two
different experiments, to be 8.565 and 8.412. The specimens which
were examined by M. Rose were adhering to greenish-grey talc slate,
and the ore was mixed with black blende, small quantities of sulphate
of iron and of copper, and tellurium-lead.
When tellurium-silver was heated before the blowpipe on charcoal,
it fused to a black mass, which, on cooling, became covered with
* Poggeudorff s Afihi der Pbysik und Chemie,
2D2
400 Foreign and Miscellaneous Intelligence.
numerous white points and ramifications of metallic silver. It fused
also in open and closed vessels ; and, when ignited in a retort, tinged
the glass with which it was in contact of a yellowish colour : in
the open tube it deposited a small quantity of white sublimate, part of
which was volatilized by directing the flame upon it, the rest contract-
ing into small globules.
It was found to dissolve in nitric acid, particularly when heated,
but much less in nitro-muriatic acid, being soon covered by a crust
of chloride of silver. If the solution in nitric acid was suffered to
cool, small brilliant crystals were deposited, which consisted of the
oxides of tellurium and silver, but in a different proportion from what
they are in tellurium-silver, for, a short time after their formation,
crystallized nitrate of silver was deposited.
M. Rose submitted the mineral to the following analysis : — It was
dissolved in nitric acid, and after the silver had been precipitated by
muriatic acid, the solution was filtered and evaporated ; sufficient
quantity of muriatic acid was now added until all nitric acid was de-
composed, and no smell of chlorine could be perceived. The liquid
was then diluted with water and heated, and on the addition of mu-
riatic acid and sulphite of ammonia, a black precipitate was obtained,
which consisted of metallic tellurium. The remaining fluid, being
filtered, was again submitted to the action of sulphite of ammonia and
muriatic acid, and this was repeated as long as a precipitate formed.
A current of chlorine gas was then passed through the filtered liquid,
in order to oxidize completely the small quantity of iron contained in
it, and this was afterwards precipitated by ammonia.
By this process M. Rose obtained from 2.833 gramm. of the mine-
ral, 2.348 gr. of chloride of silver, which contain 1.769 gr. of silver,
1.047 gr. of tellurium, and .010 gr. of oxide of iron. By a second
analysis, 2.678 gr. of the mineral were found to consist of 1.669 of
silver, 0.988 of tellurium, and .050 of iron.
According to the first analysis, tellurium-silver consists of
Silver . . . 62.42
Tellurium . . 36.96
Iron , • . 0.24
According to the second, of
Silver . 62.32
Tellurium „ . 36.89
Iron . . . 0.50
And if tellurium-silver be considered as a compound of one atom of
silver = 62.63, and one of tellurium = 37.37, the above results are
nearly confirmed*.
The other mineral, tellurium-lead, is, like the former, not crystal-
lized, but cleavable in three directions ; the planes of cleavage are
not quite even, but seem to be at right angles to one another. Its
colour is tin white, almost like antimony, but a little more yellow ;
* According to Berzelius, the atomic weight of silver is 1351,005, and that of
tellurium 806,45, osygeu being 100.
Chemical Science. 401
it has much metallic lustre, is brittle, and of the hardness of fluor
spar: spec. gr. = S.I 59. It is mixed with small proportions of
tellurium-silver, and before the blowpipe on charcoal, fuses to a
small button, which gradually diminishes in size so as ultimately to
exhibit a small globule of silver, surrounded by a ring of metallic
hue, which seems to be formed by the volatilized and subsequently
precipitated tellurium-lead. If the flame is directed upon it, it is com-
pletely volatilized, the flame becoming at the same time of a blue
colour. It fuses also in a retort, and forms a small quantity of
white sublimate, which, under the action of strong heat, contracts
into small globules. If ignited in an open tube, it fuses and becomes
surrounded by a ring of white drops, and at the lower portion of the
tube a very dense white sublimate is deposited, which before the flame
of the blowpipe contracts into small drops.
When powdered, it dissolved in nitric acid with the evolution of red
vapours : the solution was diluted with water, and the silver con-
tained in it precipitated by muriatic acid ; the fluid was then filtered,
and the lead precipitated by hydro-sulphuretted ammonia; after
twenty-four hours the fluid was again filtered, the sulphuretted tel-
lurium precipitated from it by adding muriatic acid, and the sulphur
ultimately separated from the metal by dissolving the sulphuret in
nitro-muriatic acid, which precipitated the sulphur.
As one analysis only could be made of the mineral, M. Rose re-
frains from giving any decided opinion on its composition at pre-
sent ; he is, however, inclined to consider it as a compound of 1.28 of
silver, 60.35 of lead, and 38.37 of tellurium.
33. BERZELIUS' METHOD OP PREPARING UREA.
The following process for obtaining urea is recommended by Ber-
zelius in his recent work on Chemistry, vol. vi., p. 420, of the
Swedish original.
Recent urine is to be evaporated, and as much of the residuum as
possible taken up by alcohol. The alcoholic solution is to be evapo-
rated, and the yellow substance remaining, dissolved in a small quan-
tity of water, and digested with a little animal charcoal, until it is
rendered quite colourless. The liquid is to be filtered, heated to 50°
Centigr. (122° F.), and as much oxalic acid added as is soluble at that
temperature ; on cooling, the oxalate of urea is deposited in colourless
crystals. If, instead of 122°, the fluid is heated to 212°, the solution of
oxalic acid becomes of a brown colour and4unpleasant smell ; and the
crystals, of oxalate of urea, are of a red or reddish-brown colour, but
become colourless on adding a small quantity of animal charcoal.
On applying gentle heat, so as slowly to evaporate the fluid, the de-
position of crystals continues, and their quantity may be further
increased by adding a new quantity of oxalic acid as soon as the
fluid becomes thick and loses its sour taste. After this process, all the
crystals are collected, washed with ice-cold water, and then again dis-*
solved in boib'ng water with a little animal charcoal ; when filtered
402 Foreign and Miscellaneous Intelligence.
and cooled, the oxalate of urea is deposited, from the solution, in white
crystals. These crystals are to be dissolved in boiling water, and
powdered carbonate of lime added until litmus paper is no longer
reddened by the fluid ; the precipitate, which consists of oxalate of
lime, is to be separated by the filter, and on evaporating the remain-
ing fluid, a white salt-like mass will be obtained, which is urea, con-
taining, however, in most cases, some oxalate of potash, soda, or
ammonia. The two first of these salts are derived either from the
oxalic acid or from the urine, when, to free the alcohol completely
from water, some potash or soda has been dissolved by it ; the oxalate
of ammonia comes from the ammoniacal salts in the urine which, at
the beginning of the process, were dissolved by the alcohol. On
boiling the crystallized mass with concentrated alcohol, the oxalates
are precipitated.
The oxalate of urea has a sour taste, and forms dendritical crystals,
which, on being heated, melt and boil, giving out carbonate of am-
monia and cyanic acid ; the oxalic acid being decomposed into car*
bonic acid and carbonic oxide. They are very soluble in hot, but
much less in cold water ; at 60° F. 100 parts of water dissolve only
4.37 parts of the salt; if oxalic acid is added to the solution, part of
the dissolved urea is precipitated. Alcohol dissolves but very little
of it; 100 parts, of spec. grav. 0.833 and at 60° F., dissolve only
1.6 parts. According to Berzelius' analysis, it consists of 37.436
oxalic acid and 62.564 of urea, the oxygen in the latter being to that
of the former as two to three. It does not contain any water of
crystallization*.
34. ON THE DISTILLATION OF NITRIC ACID. — (By E. Mitscherlich.)
During the decomposition of nitre by sulphuric acid, there are some
circumstances regarding the combination of the acid with the potash
of the nitre, which have hitherto been but little attended to. Of the
three compounds of sulphuric acid and potash with which we are
acquainted, the sulphate and bisulphate only require our consideration
with respect to the above process, the former of which is sufficiently
known ; the bisulphate contains twice as much acid as the sulphate ;
and water, the oxygen of which is to that of the acid as one to six ; this
water is very fixed, and is not even evolved during the fusion of the
salt at 392° F., but only when the salt itself is decomposed ; a pro-
perty which the latter has in common with the sulphate of the prot-
oxide of iron, and some other salts. It would accordingly, perhaps,
be better to consider the bisulphate of potash as a compound of
the hydrate of sulphuric acid and the sulphate of potash : it consists
of 58.80 sulphuric acid, 34.61 potash, and 6.59 water.
If equal parts of the nitrate and the bisulphate of potash are distilled
with half a part of water, until the emission of red vapours begins,
which is the case at about 418 F.°, the water in the receiver will be
found to contain not more than 1 j per cent, acid of the nitrate em-
* From Poggendorf's Annul, der Phys, uud Chemie.
• Chemical Science, 403
ployed; and it accordingly is evident that the bisulphate and the
nitrate commence only to act on each other at that temperature.. On
increasing the heat, the retort becomes filled with red vapours ;
oxygen is evolved and nitrous acid distils over, and is dissolved by
the aqueous nitric acid in the receiver. The emission of red vapours
continues when the retort is red hot, and it appears, consequently,
that even at so high a temperature a large quantity of the nitrate ia
left undecomposed by the bisulphate.
If the quantity of sulphuric acid employed be just sufficient to pro-
duce the sulphate, the temperature required for the distillation of the
acid does not exceed 302° F. ; after half the quantity of the acid in
the nitrate has been distilled over, the residue consists of bisulphate.
and nitrate of potash, which, on increasing the temperature, act
on each other in the manner above described — viz., oxygen and
nitrous vapours are evolved, and the liquid in the receiver is coloured
by nitrous acid. The quantity of water employed in the process is
quite indifferent, and influences only the strength of the distilled
acid, which, previous to increasing the heat above 302° R, is perfectly
colourless. According to this process, that is to say, where the quan-
tity of sulphuric acid is 48.41 to 100 of the nitrate, the quantity of
nitric acid produced does not exceed six- sevenths of that previously
contained in the nitrate.
Nearly the same result is obtained by distilling 100 parts of nitre
with 72.6 of sulphuric acid ; but in this, as well as in the last process,
a very great heat is required to decompose the last proportions of nitre,
part of the acid of which will, moreover, also be found to be lost.
But if, with 100 parts of nitre, 96.8 parts of acid are used, so that
the bisulphate of potash is formed, the process will be found to be
far more profitable, for none of the acid is lost : distillation takes
place very easily, and at a heat not exceeding 248° to 257° F. ; the
nitric acid obtained is of 1.512 gravity, which, by distillation, may
be increased to 1.54. The- former, which is colourless, contains
86.17; the latter is rather yellowish, and holds 88.82 per cent, of acid.
If water is added to the acid of 1.522, the boiling point of the
liquid gradually rises ; and, on distillation, first concentrated and
then weak acid will be found to pass over. This continues, however,
only until the quantity of water amounts to 44 per cent, of the acid,
the specific gravity of which is then 1.40, and the boiling degree be-
tween 248° and 249° F. ; if the quantity of water is still increased,
the boiling point falls, and the order of the distillation is, as it were,
contrary to what it was observed before — viz., first weak and then
strong acid is obtained. This likewise takes place during the distil-
lation of nitric acid from nitre ; for if, with 100 parts of nitre and
96.8 of sulphuric acid, the quantity of water is not equal to 44 per
cent, of the acid formed, the first produce of distillation is strong,
and the next diluted acid ; if more water is employed, the contrary
takes place.
It is, accordingly, most advantageous to use 100 parts of nitre, 96.8
of sulphuric acid, and about 40.45 of water, which will be sufficient, as
404 Foreign and Miscellaneous Intelligence.
the nitrate of potash always contains some water, and the sulphuric
acid is seldom so concentrated as to contain less than 18 J per cent.
The acid distils at 266° F., and its specific gravity is between 1.4 and
1.395. 28 Ibs. of purified nitre, with 13^ Ibs. of sulphuric acid, of
1.85, yielded 34 Ibs. of nitric acid, of 1.30 specific gravity ; and the
same quantity of nitre, with 27-jr Ibs. of sulphuric acid, gave 37-J Ibs.
of nitric acid, of 1.30*. Besides, the first process required almost
twice as much fuel and much more time than the second.
In conclusion, M. Mitscherlich mentions some remarkable proper-
ties of nitric acid, of 1.522 specific gravity. Iron, tin, and several
other metals, may be put into, and even boiled in it, without the
least effect ; whilst zinc is immediately oxidized and dissolved!.
35. ON A PECULIAR PROPERTY OF ALLOYS. — (By F. Rudberg%.)
In a course of experiments which I lately made on the specific heat
of lead and tin and some of their alloys, I observed a very remarkable
proportion attending the specific heat of these alloys, and was parti-
cularly struck when, on repeating the experiments on other metals,
I found the same proportion also to take place in them ; so that it
might, perhaps, be considered as a general property of alloys.
The following apparatus was used in the experiments : — A cubic
vessel of thin iron plate, eight inches in height, was placed in ano-
ther, of such dimensions that the sicles of the outer were everywhere
two inches distant from the inner vessel ; the intermediate space was
filled with snow. The larger vessel could be closed with a cover,
the lower surface of which was blackened, and the upper covered with
snow. In the middle of the central vessel, the inner surface of which
was also blackened, there was a very thin cup of tin-plate on a ring
of platina, suspended by platina wire from the sides of the inner
vessel. A cover of tin-plate was made exactly to fit the opening of
the cup, and had a central opening for a cork, through which the
tube of a Centigrade thermometer passed§ ; so that, if the cover was
placed on the cup, the bulb of the thermometer was nearly in its
middle. The external surface of both the cup and cover were
blackened.
The cup having been put on the ring was filled with the metal, or
alloy, whilst in a state of fusion ; the cover, with the thermometer,
which had been previously heated, was placed on it, the external
cover also put on, and the time which the mass required for cooling,
carefully watched. By comparing the different lengths of time which
the metal or alloy requires to cool, every ten degrees before and
after its becoming solid, with those which mercury requires for the
* According to Thenard, from 100 parts of nitre and 66 % of sulphuric acid
40.8 of very strong nitric acid, and from the same quantity of nitre with 144 parts
of sulphuric acid, 81.6 parts of nitric acid of the same strength were obtained.
These results appear to M. Mitscherlich to be erroneous.
•f Poggendorff's Annalen.
J From the Kongl. Svensk. Vetensk. Acad. Handlingar, 1829.
§ All the temperatures in this paper are expressed in the Centigrade scale.
Chemical Science. 405
same ten degrees, the specific heat of the metal or alloy may be
easily determined ; for as all external circumstances and the difference
of temperature are the same, the loss of heat which mercury expe-
riences will be, to that of the alloy, in the ratio of the different
lengths of time ; and as, by the experiments of MM. Dulong and
Petit, the specific heat of mercury has been ascertained both for
high and low temperatures, that of the alloy may accordingly be cal-
culated.
Whilst determining, in this manner, the specific heat of lead and
tin, and several of their alloys, at different temperatures, I found, in
general, the thermometer to be stationary at two points — one of
which was the same for all alloys of the same nature, whilst the other
varied according to the proportion of the two metals. I then exa-
mined the alloys of other metals, and obtained a similar result, as
will be seen from the annexed table, which exhibits the observations
on the alloys of lead and tin, tin and bismuth, and tin and zinc.
The metals were combined in their simple atomic proportions, as is
indicated by the number affixed to the initial of each metal.
The first table contains the observations on lead and tin ; the for-
mer of which becomes solid at 325° C., the latter at 228° C. In the
alloys, the thermometer was stationary at 167° C. ; and the length of
time, between 190° and 180°, is accordingly much more considerable
than that of any of the preceding or following ten degrees. Besides
this fixed point, (as it might perhaps be called, with reference to the
other variable one,) there are other retardations of the thermometer,
according to the proportion of the respective metals ; as, in L3 T,
between 290° and 180° of 1' 36", in L2 T between 280° and 270°, of
1'6", &c. On increasing the quantity of tin, the variable was ob-
served to approach the fixed point, and in the alloy L T8 they coin-
cided ; in L T4 the thermometer was stationary for a few moments
when at 190°, or just below, and then suddenly fell to 187°. In L T8
the retardation became again more distinct, being of 3' 5" between
210° and 200° ; and in LT12, of 4' 23", between 220° and 210°.
It seems then that there exist, for all alloys of lead and tin, (except
for L T 3,) two points at which the thermometer is stationary — the
one which is fixed at 187°, the other being variable, according to the
proportion of the metals, but always at a higher temperature the
more distant the mixture is from the combination L T 3. The length
of time during which the thermometer is stationary on the fixed
point also decreases in the same ratio, until it becomes =0 ; when
the metals are simple, the fixed point is then the same with that
of their congelation.
The second table gives the result of the observations on the alloys
of tin and bismuth; the fixed point is 143°, the variable point
evidently coincides with the fixed one in T8 B2; and, according
to the different proportions of the alloy, is near to, or distant from,
the temperature at which the simple metals become solid.
The third table contains the experiments on the alloys of tin and
406 Foreign and Miscellaneous Intelligence*
r t O •**
™ W *S <
•*' + ' +
G» ^O iO *"f CO C*l *"— O O> OO **«* o^^<>ni-C'-^co»na5-f. ^^
_ ^ ^ ,_ _ _ _ 0(J ' ' ' \49.745J76'32
Water 9.532 9.00*'
* Poggendorf'a Ann, der Pbysik und Chemie, 1830, p, 5(J7.
Chemical Science. 411
37. ON MAGNESIUM. — (Justus Liebig.)
The Annales de Chimie, of March, 1830, contain a paper by M.
Bussy, on magnesium, which he obtained by the action of chloride
of magnesium on potassium ; the properties of this metal appeared
to M. Liebig to be so very extraordinary, that he was induced to
make some experiments on it.
M. Bussy's method of obtaining the chloride consists in passing
chlorine gas over a mixture of magnesia and charcoal, whilst in a
state of ignition ; it may, however, also be obtained by evaporating
equal parts of the muriates of ammonia and magnesia, and heating
the dry residuum in a platina vessel, until the muriate of ammonia is
completely expelled, and the mass becomes fused. The remain-
der is chloride of magnesium, and if left to cool, forms white trans-
parent leaf- like crystals.
In order to reduce the chloride of magnesium, from about 10 to
20 small globules of potassium are put into a glass tube, three or
four lines in diameter, the chloride is placed over them, and heated
over charcoal, until it begins to flow ; the tube is then slightly in-
clined, so that the potassium runs through the chloride, which is thus
reduced to magnesium with the evolution of light. If the mass,
when cold, be treated with water, a large quantity of small metallic
globules will be collected at the bottom of the vessel ; they are of a
silver-white colour, have much metallic lustre, and, though malleable,
are very hard ; neither cold nor hot water acts on them. If mixed
with chloride of potassium, and heated in a crucible, they may be fused
into one mass, and their point of fusion does not apparently exceed
that of silver. The metal is dissolved by diluted acetic acid, as well
as by sulphuric and nitric acids, with the evolution of hydrogen gas,
and sulphurous and nitrous vapours: the solutions are found to
contain no other oxide besides magnesia. When heated in atmos-
pheric air or oxygen gas, the metal burns with the most vivid light ;
the vessel is covered with magnesia ; and at the place where the
metal was, a black spot remains, which seems to be silicium, as it
was not destroyed by boiling hot acids. Sulphur did not seem to
unite with the metal, when both were fused together. The solution
in sulphuric acid yielded, on evaporation, crystals of sulphate of
magnesia*.
38. ON THE EXPANSION OP BISMUTH AND ITS ALLOYS DURING
CONGELATION. — (Professor Marx, of Brunswick.)
Bismuth is known to be a very remarkable instance of apparent ex-
ception from the general rule, that fluids contract when becoming
solid ; and it corresponds with water in this respect also, that it com-
municates this property to other bodies, particularly metals, if it
forms a certain proportion of the alloy. Where the maximum of
* Poggeudorf 's Aunalen.
412 Foreign and Miscellaneous Intelligence.
density lies, and in what degree the volume of the solid metal exceeds
that of the fused, has, as far as we know, not yet been ascertained ;
but the former is probably very near the point of congelation ; and of
the latter, an approximate evaluation may, according to Professor
Marx, be made in the following manner. If a quantity of bismuth
be fused in an iron spoon or a glass tube, and then removed from the
fire, the mass remains fluid for some time ; it then congeals at the sur-
face, but after the whole seems to be quite solid, all at once a large
quantity of globular masses protrude from the surface, which are
always proportional to the quantity of the metal employed, and
may perhaps serve to determine the quantity of expansion ; this was,
according to several experiments of Professor Marx, found to be
about -^ of the weight of the whole, and consequently less than a
third of the expansion of water. The force with which bismuth
expands is so considerable, as to break glass tubes in which the fused
metal is allowed to cool : thus, if a thermometer tube is plunged into
fused bismuth, and then filled with it by sucking the metal up, it
always breaks within a short time with a loud cracking, and in several
directions, but mostly longitudinally, so as to form long parallel glass
fibres. For the success of this experiment, it is, however, necessary
to make the column of metal long enough, otherwise its longitudinal
increase will cancel the expansion. The following were the alloys
of bismuth, which Professor Marx examined : —
i. Bismuth and Sodium. — Four parts in volume of powdered
bismuth, and one of sodium, were heated in an iron spoon. Long
before the fusion of the bismuth, the sodium united with it, with
the evolution of vivid light ; the alloy was more fusible than bismuth,
of a steel grey colour, and did not change by the contact of the
air, until after some days, when its surface became covered with
a black powder. If the alloy be fused, and then allowed to cool, the
projections also formed, but to a much less degree than in pure
bismuth ; nor were the thermometer tubes burst, as in the above expe-
riment. The alloy, with potassium, offered nearly the same results.
ii. Bismuth and Arsenic. — This alloy, consisting of three parts of
the former, and one of the latter, did not seem to expand at all
when becoming solid ; on increasing the quantity of bismuth, the
effects ofjexpansion gradually became visible, and in the alloy BM Arl
were almost as great as in bismuth alone.
iii. Bismuth and Antimony.— It having been frequently remarked
that antimony, like bismuth and water, expands on becoming solid,
Professor Marx made several experiments in order to ascertain it,
but without coming to any decided result ; the alloy of both metals,
in equal parts, exhibited the same phenomena as pure bismuth. This
was also the case in the alloys B1 Ant.2, and Bl and Ant.4, though in
a less degree.
iv. Bismuth and Zinc. — Zinc on becoming solid contracts so
much, as to exhibit the contrary to what is observed in bismuth, the
surface becomes depressed, and the wire in the thermometer tube
often breaks into several pieces ; the tube also bursts sometimes, but
Chemical Science. 413
always transversely, probably because it cannot follow the rapid
contraction of the metal. Equal parts of zinc and bismuth fuse at a
point below the fusion of bismuth ; in cooling they separate, on
account of the greater weight of the bismuth.
v. Bismuth and Tin. — Equal parts of both, present the same phe-
nomena as pure bismuth.
vi. Equal parts of Bismuth and Lead, on the contrary, do not
expand; and even if the quantity of bismuth is several times that of
lead, there is but a slight increase in bulk. In B° L1 the bismuth
seems to have almost recovered its expanding force.
vii. Bismuth, Tin, and Lead. — The alloy B2 Tl L1 is known for
its great fusibility, the point of fusion being below 180° F. On be-
coming solid, the surface is rather depressed, and the mass seems
accordingly to contract ; and in most cases, however, the thermo-
meter tubes burst longitudinally a long time after the mass has be-
come solid. The tin seems, accordingly, under these circumstances,
to overbalance the equalizing force of lead.
The following table shows the volume of this alloy, according to
the experiments of M. Erman *.
Temperature.
Volume.
Temperature.
Volume.
Temperature.
Volume.
32
R.
1.
007-297
50
R.
0.992921
68
R.
0.996802
35
1.
008364
53
0.
992150
71
1
.001057
38
1.
007353
56
0.
991337
74
1
.008022
41
1.
006390
59
0.
992071
77
1
.011576
44
1.
001466
62
0.
993640
80
1
.017929
47
0.
996196
65
0.
994788
The alloy B2 L1 Tl did not exhibit the phenomena of expansion.
viii. Bismuth and Copper. If the quantity of bismuth is twice
that of the copper, the expansion takes place a considerable time
after congelation; but if the copper forms only the fifth part of the
alloy, it is observed during, and immediately after, its becoming
solid.
ix. Bismuth and Mercury does not seem to expand.
x. Equal parts of Bismuth and Silver do not increase in bulk ;
but if the bismuth is twice the quantity of silver, the expansion is
very evident.
xi. Phosphorus could be made to unite with bismuth in small
quantities only, and the expansive power of the metal was not altered
by it; in the combination of sulphur and bismuth, however, the ex-
pansion seems to be considerably increased, almost to the fourth
part of the mass. Professor Marx tried the combination of sulphur
with several other metals, but without obtaining any similar result.
This peculiarity of the mixture of bismuth with sulphur, and the
known fact that fused sulphur at an increased heat becomes viscous,
and then fluid again, led Professor Marx to make some experiments
on sulphur alone, the result of which was, that contrary to bismuth
* 32°R. = 104°F. 80°R. = 212°F. 4°R. = 9°F.
VOL. I. FEB. 1831. 2 E
414 Foreign and Miscellaneous Intelligence.
and water, liquid sulphur contracts on becoming solid. He thought
it, however, worth while to submit sulphur to another kind of ex-
amination, viz., by observing the different lengths of time which it
requires to cool within certain limits, as he anticipated that in case
the density varied according to the different degrees of liquidity, this
would appear from the falling or rising of the thermometer. The
sulphur was left to cool in the open air, the temperature of which was
about 7J° R., and fell during the experiment 1J°. The time was
observed during every five degrees by a very accurate watch, the
minute of which was divided into 75 seconds. The following table
gives the result of five series of experiments : —
150° R. I. II. III. IV. V.
145
1'51"
V3S"
60"
67"
140
ri5"
]/4/"
59
60
135
61
72
42
49
130
60
65
29
48
125
69
53
29
47
120
51
58
38
50
115
60
73
I'o"
56
45
110
57
69
70
65
55
105
69
69
73
61
47
100
63
71
72
67
49
95
70
74
VI
74
V12
90
V2
1'7
V3 -
V4
V3
85
67
1'14
V9
V4
I'l
Solid
fS6j°\
«'a//J89° \i.
w«f/J®7s li i/i
71/,J884°
j 88 J°\ ,,,,,„
between! 83° P J \82iT1 \™° j \80C
The observations of I. and II. relate to sulphur which had not
been melted before ; those of III. were made on the sulphur of I.,
as were also the observations of V. ; the sulphur of IV. was the
same which had been used in II. From these experiments it would
result —
1. That sulphur, after having been heated to 150° R,, slowly
expands, whilst cooling, to about 125° ; the gradual decrease of the
lengths of time appear, at least, to show that latent heat becomes
free.
2. That from 125° downwards, there is a gradual contraction
corresponding to the increase of the lengths of time.
3. That the degree at which sulphur becomes solid falls between 79°
and 89°.
4. That during the congelation of sulphur, a greater quantity of
heat becomes free than at the solidification of, perhaps, any other
body*.
* Schweigger Seidcl's Jahrbuch der Chemie und Physik.
Natural History, fyc. 415
$ 3. NATURAL HISTORY.
1. FORMATION OF HAIL.
M. de Perevoschtchikoff has endeavoured to support experimentally
the objections made by Bellani against Volta's theory of hail, and
to develope the influence of evaporation on the temperature of liquids.
He used a thermometer with the tube bent, so that the ball was
turned upwards, and the upper part of the ball was dished, so as to
form a receptacle for fluid ; in this way the temperature of any fluid
evaporating from the part could be ascertained. From his experi-
ments with water, he found that a prompt evaporation produced cold,
even under the direct influence of the sun. From experiments with
spirit of wine, he concluded that the temperature of an evaporating
liquid could not rise, except when the evaporation was feeble ; and
he ultimately concludes, that the cause of the first formation of hail
exists in a prompt evaporation of the vesicles constituting clouds.
According to him, Volta lost sight of the principal cause of the
cooling of clouds, and also of the concentric structure of hail-stones.
The correct account of the phenomenon he conceives to be the
following : — When the clouds consist of many thick strata, which
gradually rise, they become an obstacle to the free distribution of the
radiant heat from the earth, which being reflected back again,
produces that suffocating sensation which usually precedes the storm.
Above the clouds, however, the heavens are serene, and consequently
radiation goes on freely from their upper surface. Hence the prin-
cipal cause of the refrigeration upon which depends the formation of
the nucleus of the hailstone. The specific gravity of these nuclei
being too great to allow of their remaining suspended in the cloud,
they fall ; and traversing different strata of clouds, they become
covered at each, by a fresh opaque coat of the liquid, congealed at
their surface, the number of layers in the hailstone corresponding to
the number of strata it has passed through. The hailstones, by con-
cussion against each other, are supposed to have a rotatory motion
given to them, tending to produce the spherical form. The author
concludes that paragreles, or hailrods, are not only useless, but
even dangerous*.
2. GEORGIA METEOR AND AEROLITE.
The following is a very circumstantial account of the descent of the
stone which fell in May, 1829, at Forsyth, in Georgia, United States.
Between three and four o'clock on the 8th instant, on that day a
small black cloud appeared south from Forsyth, from which two dis-
tinct explosions were heard, following in immediate succession, suc-
ceeded by a tremendous rumbling or whizzing noise passing through
the air, which lasted, from the best account, from two to four minutes.
This extraordinary noise was on the same evening accounted for by
* Bib. Univ. 1830, p. 410,
2E2
416 Foreign and Miscellaneous Intelligence.
Mr. Sparks and Captain Postian, who happened to be near some
negroes working in a field one mile south of this place, who disco-
vered a large stone descending through the air, weighing, as was
afterwards ascertained, thirty-six pounds. The stone was, in the
course of the evening or very early the next morning, recovered from
the spot where it fell. It had penetrated the earth two feet and a half.
The outside wore the appearance as if it had been in a furnace ; it
was covered, about the thickness of a common knife-blade, with a
black substance somewhat like lava that had been melted. On break-
ing the stone it had a strong sulphureous smell, and exhibited a
metallic substance resembling silver. The stone, however, when
broken, had a white appearance on the inside, with veins. By the
application of steel it would produce fire. The facts, as related, can
be supported by many individuals who heard the explosion and
rumbling noise, and saw the stone*.
The following notice of the same event was given by Dr. Boykin,
in June, 1830: — ' No one can tell from what direction the meteor
came. The first thing noticed was the report like that of a large
piece of ordnance ; some say the principal explosion was succeeded
by a number of lesser ones in quick succession, similar to the explo-
sions of a cracker ; one has told me the secondary noise was only a
reverberation. Very soon after the explosions some black people
heard a whizzing noise, and on looking, saw a faint "smoke" descend
to the ground, at which time they heard the noise produced by the
fall of the stone: they ran to the spot, for they saw where it fell, and
discovered the hole it had made in the ground, being more than two
feet in a hard clay soil : the negroes, and others who went early to
the spot, say they perceived a sulphureous smell. The stone weighed
thirty-six pounds ; it fell at a small angle with the horizon.
Dr. Silliman adds, that ' having received the specimens just as
this number of the Journal is about being finished, I can add only the
following notice. The colour of the interior of the stone is of a light
ash-grey, and very uniform, except that it is sprinkled throughout
with thousands of brilliant spots of metallic iron, having very nearly
the colour and lustre of polished silver. The iron is rarely in points
larger than a small pin's head, but the points are so numerous that
nearly the whole of the powder of the stone is taken up by the mag-
net, even when it is in fine dust, and by a magnifier the little points
of iron can even then be seen standing out from the magnet. It
greatly resembles the Tennessee meteorite. It has the usual black
crust on certain parts, and this, although resembling a semi-fused
substance, exhibits bright metallic spots when a file is drawn across
it. A similar black crust is seen pervading the stone in some places
through its interior, and forming, where it is seen in a cross frac-
ture, black lines or veins. The stone is full of semi-fused black
points and ridges similar to the crust, and its entire mass seems half
vitrified in points, so as to resemble an imperfect glass/
The specific gravity, as ascertained by Mr. Shepard, is 3.37.f
* Elias Beall. . f Silliman's Journal, xviii., p. 388.
Natural History, fyc.. 417
3. ON THE THERMAL WATERS OF CHAUDES AIGUES, IN THE
DEPARTMENT DU CANTAL. — (M. Chevalier.')
The little village of Chaudes Aigues is situated to the south of St.
Flour, on the border of a stream in a pleasant valley, surrounded by
high mountains. Its mineral waters have long enjoyed some cele-
brity, but have fallen into medical disuse. At present establishments
are forming for the reception of patients, and many circumstances
combine to render the place agreeable and tempting, and so to favour
the enterprise. The sources of the Par, which is the largest of all,
yield 230 cubic metres and 4 decalitres every twenty-four hours ; its
temperature is at 80° C. (170° F.) It is this water which the inhabi-
tants employ by means of ingeniously contrived conduits, which
conduct it to the houses, to give warmth during the winter: in the
summer they turn it away towards the river, that they may not be
inconvenienced by its heat. This practice should be followed at
other towns where there are sources of hot water, as at Plombieres,
Aix, &c. M. Berthier has calculated, that the water of the Par is equi-
valent, as a heating agent, to the wood which would be furnished by a
forest of oaks 540 hectares (1334 acres) in area. The water of this
spring is clear, limpid, and almost tasteless ; it leaves a slight ochra-
ceous film upon stones ; it becomes spontaneously covered with a
thin oily film, but may be retained a long time unaltered. It issues
from massive sulphuret of iron, and its channels are obstructed by a
deposit of the same substance.
The second spring is that of the mill of Ban. It flows over
quartz, serving as the gangue for sulphuret of iron. This water is
conducted to the hospital and several private houses, in the same
manner, and for the same purpose, as the preceding water.
The third spring, that of the Grotto of the mill, is particular in
this circumstance, that, though less hot than the others, it follows
exactly the same changes of temperature. At its source it disen-
gages carbonic acid mixed with oxygen and azote.
The Maison Felgere is in possession of four springs, one of
which is at the temperature of 70° C. (158° F.) The water of the
river, heated by all these streams, is said to be more favourable in
exciting vegetation than other rivers.
These waters, besides being applied to heat apartments, are used
also to cleanse wool, and M, Felgere has formed an establishment for
the hatcliing of eggs, in imitation of that arranged by M. d'Arcet, at
Yichey.
M. Chevalier has obtained, by chemical analysis, from 20 litres
(1220 cubic inches) of the Par water : — i. A trace of hydrosulphuret
of ammonia, which appears to be formed by the action of heat. ii. An
organic animaiizcd matter, which appears as flocculi, when the water
is evaporated, and sometimes occurs united to carbonate of lime,
iii. 18.86 grammes (291 grs.) of a light solid substance, more than
half composed of subcarbonate of soda. These waters, by their heat
418 Foreign and Miscellaneous Intelligence.
and purity, are very analogous to those of Plombieres, a circumstance
in favour of the formation of a similar establishment*.
4. HUMBOLDT'S ACCOUNT OF THE GOLD AND PLATINA DISTRICT
OF RUSSIA.
The following account is part of a letter from M. Humboldt to M.
Arago: — ' We spent a month in visiting the goldmines of Borisovsk,
the malachite mines of Goumeselevski and of Tagilsk, and the wash-
ings of gold and platinum. We were astonished at the pepitas
(waterworn masses) of gold, from 2 to 3lbs., and even from 18 to
SOlbs., found a few inches below the turf, where they had lain un-
known for ages. The position and probable origin of these alluvia,
mixed generally with fragments of greenstone, chlorite slate, and
serpentine, was one of the principal objects of this journey. The
gold annually procured from the washings amounts to 6000 kil.
The discoveries beyond 59° and 60° latitude become very important.
We possess the teeth of fossil elephants enveloped in these alluvia
of auriferous sand. Their formation, consequent on local irruptions
and on levellings, is, perhaps, even posterior to the destruction of the
large animals. The amber and the lignites, which we discovered on
the eastern side of the Ural, are decidedly more ancient. With the
auriferous sand are found grains of cinnabar, native copper, ceyla-
nites, garnets, little white zircons as brilliant as diamonds, anatase,
alvite, &c. It is very remarkable, that in the middle and northern
parts of the Ural, the platinum is found in abundance only on the
western European side. The rich gold- washings of the Demidov
family, at Nijnei'-tagilsk, are on the Asiatic side, on the two acclivi-
ties of the Bartiraya, where the alluvium of Vilkni alone has already
produced more than 28001bs. of gold.
The platinum is found about a league to the east of the line of the
separation of waters (which must not be confounded with the axis of
the high summits), on the European side, near the course of the
Oulka, at Sukoi Visnin, and at Martian. M. Schvetsov, who had
the good fortune to study under Berthier, and whose learning and
activity have been most useful during our travels in the Ural, disco-
vered chromate of iron, containing grains of platinum, which an able
chemist at Catherineburgh, M. Helm, has analyzed. The washings
of platinum at Nijne'i-Tagilsk are so rich, that 100 puds (about 400
Ibs. Russian) of sand afford 30 (sometimes 50) solotniks of platinum,
whilst the rich alluvia of gold at Vilkni, and other gold washings on
the Asiatic side, do not give more than \\ to 2 solotniks in 100 puds
of sand. In South America, a very low chain of the Cordilleras,
that of Cali, also separates the auriferous and non-platiniferous sands
of the eastern declivity (Popayan) , from the sands of the isthmus of
the Raspadura of Choco, which are very rich in platinum as well as
gold. M. Bousingault may, perhaps, already have thrown a new
• Bib. Univ. 1830, p. 220.
Natural History, fyc. 419
light on this American formation, and his observations will derive
some additional interest from those which we have made in this place.
We possess pepitas of platinum, of many inches in length, in which
M. Hose has discovered beautiful groups of crystals of the metal.
* As to the greenstone porphyry of Laya, in which M. Engelhardt
has observed little grains of platinum, we have examined it on the
spot with much care, but the only metallic grains which we have been
able to detect in the rocks of Laya, and in the greenstone of Mount
Belayr-Gora, have appeared to M. Rose to be sulphuret of iron ; this
phenomenon will be a subject for new research. The work of M.
Engelhardt on the Ural seemed to us to be worthy of much praise.
Osmium and iridium have also a particular locality, not amongst the
rich platiniferous alluvia of Nijnei'-Tagilsk, but near Belemboyevski
and Kichtem. I insist upon the geognostical characters drawn from
the metals which accompany the grains of platinum at Choco,
Brazil, and in the Ural.'*
5, PARROT'S EXPEDITION TO ARARAT.
A scientific expedition set out from Dorpat some time since, under
the direction of Dr. Parrot, charged with the examination of the
country around Mount Ararat. After many fruitless attempts, Dr.
Parrot arrived at the summit of Ararat, and measured the height of
this celebrated mountain. He found it to be 16,200 feet in elevation,
which makes it 1500 feet higher than Mont Blanc. Dr. Parrot
caused a barometric levelling to be taken by M. Behaghel, one of his
companions, of the whole route from Tiflis to Ararat, as well as of
that which leads from this city, by Imerethi and Mingrelia, to the
Kalch redoubt on the banks of the Black Sea ; but his observations
are not yet calculated. This traveller describes the western summit,
which is the most elevated part of Ararat, as being a plain of about
150 paces in circumference; eastwards it communicates by a low
Elateau with the other summit, which is not so high; at about 1200
set of elevation everything is covered with ice and snow. The in-
struments which Dr. Parrot had with him, consisted of a pendulum
apparatus, a magnetic inclinatorium of ten inches, barometers, a sur-
veying apparatus, &c. In point of astronomical instruments, the
expedition was provided with a Reichenbach's theodolite of eight
inches, an Arnold's chronometer and one of Maynie's, a Dollond
telescope of three feet, and a Trongleton's sextant.
Dr. Parrot was accompanied, as we before mentioned, by MM.
Behaghel, a mineralogist, Schiemann, a zoologist, and Hehn, a bo-
tanist— all three students in the university of Dorpat f.
6. CUTICULAR PORES OF PLANTS.
It is well known to botanists that the cuticle of most plants is
furnished, especially on the leaves, with minute organs, the func-
* Edin. Geog. Journ, ii. 441. f Ibid. iii. 38.
420 Foreign and Miscellaneous Intelligence.
tion of which is a matter of conjecture, and the actual structure
of which has given rise to much difference of opinion. These
organs have received the names of pores, or glands, or stomata,
according to the views of different observers ; and while one class
of botanists has considered them of unknown function and struc-
ture, others have contended that they are of the nature of pores, and
that their office was, according to the one, to facilitate evapora-
tion— to the others, to assist in the process of respiration. Their
function is obviously of so obscure a nature, that no direct experi-
ments are likely to demonstrate exactly what it is ; but their structure
is a point upon which observation may be expected to cast some light.
Mr. Bauer long ago represented these organs in the wheat, as perfora-
tions opening into a minute subcutaneous cavity, and as destined to
afford a direct passage into the interior of a plant for those minute
fungi, whose ravages are so well known in the form of what the far-
mers call the mildew in corn. Other observers have, however, doubted
whether the supposed perforations always existed ; and Mr. Lindley,
in his lectures in the University of London, has repeatedly expressed
his difficulties upon the subject. The fact is, that they are so minute,
the tissue of which they consist is so exceedingly transparent, and it
is so difficult to examine them, except by the aid of transmitted light,
that it is not, perhaps, possible to determine positively in all cases
whether a perforation exists or not. Mr. Robert Brown has re-
cently published some observations upon them, from which it is to
be collected that, in the opinion of that distinguished observer, the
stomata are rather of the nature of glands than of pores, and are un-
doubtedly in many cases imperforate — evidently having in their disc
a membrane which is more or less transparent, sometimes opaque, or
very rarely coloured. The existence of colouring matter in the
stomata is the only circumstance that could have enabled an observer
to prove their imperforate nature ; for, in colourless membranes, such
as those of Crinum, in which the stomata are particularly large, the
best microscopes, employed under the most favourable circumstances,
show nothing but an apparent orifice, closed up occasionally by the
dilatation of two glandular bodies placed beneath it. Mr. Brown
states, what was certainly a very unexpected fact, that these bodies
will often, in proteaceous plants, by their figure and position, or
magnitude, with respect to the meshes of the cuticle, determine the
limits or even affinities of genera, or natural sections.
7. SMUT IN CORN.
This substance, which has been sometimes considered a mere organic
disease, but more usually a parasitical plant, analogous to that
which causes the mildew and the rust, and which has been described
under the names of Reticularia segetum, Uredo segetum, and Uredo
carbo, has been lately the subject of a particular inquiry on the
part of M. Adolphe Brongniart, who thus describes the parts in
which this malady is found, and who adopts the opinion that it
Natural History, 8fc. 421
is caused by the ravages of a kind of fungus. ' The axis which
supports the glumes and floral organs of grasses, is formed of elon-
gated cellular tissue, the cellules of which are placed close together,
without sensible intercellular passages, and of fibro- vascular bundles
of false trachea? or ducts, and spiral vessels ; in the fleshy mass, of
which the smut consists, no structure of this sort is visible, at what-
ever time it is examined ; but, for examining it satisfactorily, I have
taken the plant at the earliest period when the spike is capable of being
examined. At this time the fleshy mass is found to consist entirely
of an uniform tissue, containing uniform four-sided cavities, separated
by partitions formed of one or two layers of very minute cellules.
These cavities, which, in organization, resemble the regular Iacuna3
observable in the cells of aquatic plants, are filled by a compact
homogeneous mass, composed of very small granules, perfectly sphe-
rical and uniform in size ; they were slightly adherent to each other,
and of a greenish colour in spikes but little developed — distinct, or
simply clustered towards the centre of each mass, and of a pale
nut colour, in spikes which were a little developed : finally, at a
more advanced period, the cellular partitions disappear, the glo-
bules separate completely, and the whole mass is transformed into a
cluster of powder, formed of very regular globules perfectly alike,
black, and quite analogous to the reproductive bodies of other
fungi.'
8. STRUCTURE OF LEAVES.
A memoir, by M. Adolphe Brongniart, upon the structure of leaves,
and on their relation with the respiration of vegetables in air
and water, has been read before the Academy of Sciences of Paris.
The author states that the leaves of plants that live in the air
have a totally different structure from those that are completely
submerged, and that this difference in the structure of organs is
in direct relation to the two principal functions of leaves, respira-
tion and transpiration. In leaves exposed to air, the surface of
the leaf is covered by an epidermis of uncertain thickness, formed
of one or more layers of colourless cellules, closely packed toge-
ther. This membrane is pierced with the pores usually known by
the name of stomata. The doubts that have been entertained upon
the existence of perforations in these stomata, M. Brongniart thinks
he has removed, and that it is certain that in the centre of each
stoma is an opening by which the outer air communicates with the
parenchyma. This parenchyma is evidently the seat of respiration ;
for it is the part that changes colour in exercising this function, which
becomes green by the absorption of the carbon of the carbonic acid
of the atmosphere, and which is discoloured again in darkness by
the combination of the carbon of its juices with the oxygen of the
air. This parenchyma differs entirely from that of other organs by
the numerous irregular cavities that it contains, which communicate
with each other and the outer air by means of the openings of the
422 Foreign and Miscellaneous Intelligence.
stomata. It is into these cavities in the cavernous parenchyma of
aerial leaves that the atmospheric air penetrates when it is absorbed
by the surface of the utricles of the parenchyma, that are distended
with the fluids which seem to nourish the plant.
According to M. Brongniart, aquatic leaves, if submerged, differ,
in being completely destitute of epidermis. It is not alone stomata
that they want, as has long been known, but the epidermis also.
There are none of the cavities that abound in the parenchyma of
aerial leaves, but, on the contrary, the cellules of the tissue are com-
pactly fastened together without any interstice, and the air dissolved
in the water can only act on their outer surface. For this reason the
proportion borne by this surface to the whole mass of the leaf is
unusually great ; the leaves, from want of epidermis, dry up quickly
when exposed to the air, and can only exist in water or a very
humid atmosphere.
Hence the author concludes that the epidermis is destined to pro-
tect aerial leaves against too rapid evaporation, and the stomata or
pores of this epidermis become necessary to maintain a communica-
tion between the atmosphere and the parenchyma.
9. CRYSTALS OF OXALADE OF LIME IN PLANTS.
M. Turpin has discovered that the cellules of Cereus Peruvianus con-
tain an immense quantity of crystals of oxalate of lime. He represents
them as appearing to the naked eye like very fine glittering sand,
and, under the microscope, as rectangular prisms, with tetraedral
points and a square or parallelogrammic base : their size is variable ;
they are sometimes found collected in groups of three and four, but
more commonly forming radiating spheroidal clusters, composed of
crystals of various sizes. They existed in such abundance in some
parts of the tissue as to form at least an 80th of the whole mass.
The presence of such crystals in the tissue of plants has lately
become well known to botanists, and are distinguished by the name
of raphides. They may be found abundantly, in the form of needles,
in the common Hyacinth, and in most succulent Monocotyledons,
and in Phytolana decandria they give a kind of silvery appearance
to the subcuticular tissue ; but in no plants had they been previously
seen so abundant or so large as in the plant which forms the subject
of M. Turpin's memoir.
10. GROWTH OF VEGETABLES.
There is no subject in vegetable physiology more obscure than
the manner in which plants increase in size. While botanists
are at issue as to such a point as the origin of the wood and
the bark of dicotyledonous trees, it is scarcely to be expected that
they should agree upon the mode in which development is effected.
In truth, nothing whatever certain is known upon the subject.
Natural History, #c. 423
Lately, M. Amici, the celebrated Modenese professor, has published
some observations which he hopes may throw light on the inquiry.
It is well known that, in the spring, the sap of the vine exudes
copiously if the plant is ever so slightly wounded, and that the
discharge which, in consequence of its limpidity, is fancifully called
the * tears ' of the vine, becomes, after a short exposure to the air,
of a rusty brown. M. Amici states that he found this substance,
when examined under the microscope, to consist of long interlaced
filaments, which were generally simple, but sometimes subdivided
into two or three bifurcations. These filaments, or tubes, consisted
of numerous joints separated by diaphragms, and, while some of the
cells were filled only with air, others contained little moveable
granules. Upon examining the vine sap in its limpid state, it was
found to be entirely destitute of any trace of organization, but it was
seen that the filamentous matter made its appearance upon being
exposed to the sun for six hours, twelve hours after having been
collected. One of these filaments was seen to multiply its original
volume 24 times in the space of ten hours, and to have at the same
time given birth to two young buds. Wishing to follow the deve-
lopment of this vegetation still further, the same object was left
eleven hours longer upon the field of the microscope ; at the end of
this period it had grown from 0.2375 of a millimetre in length to
2.25, and had ramified and subdivided like a tree, and presenting
joints formed at intervals by diaphragms ; some of these joints
contained very small granules, which circulated completely in the
cavity of the cellules and of the tubes. This organization is ob-
viously that of a Conferva ; but M. Amici justly remarks that its
constant existence in the tears of the vine makes it improbable
that it should be of such a nature ; and, at all events, the fact is
one highly deserving the attention of physiologists.
rT"~" r
Fig. 1. ,
2.
1.
Figs. 1, 2, and 3 are magnified 1500 times; Fig. 4, 500 times.
I is one variety of the filaments found in the red mucilage ; it
includes two joints formed by diaphragms; in the part between
them are the small granules, which circulate round the whole
included space as in the Cliara. Fig. 2 is another variety of tube
with various compartments or vacuities between the joints; these
424 Foreign and Miscellaneous Intelligence.
may be false tracheae. Fig. 3 is a third variety, which occurs where
the vacuities are smaller ; these may be the elements of porous tubes.
Fig. 4 is the case, described as seen under the microscope ; at first
the lateral shoot extended like a bud only to the first mark ; at the
end of one hour it had reached the second ; at the end of the second
hour it had attained the third mark, and at the end of the third hour
to the full extent figured, and had produced the two small buds or
commencements. When the growth of the tube is seen under a high
power, it appears as if it were a viscid substance pushed from within
by an elastic fluid, which extends its length, but not its breadth.
By degrees, molecules, or small grains appear, in the vacuities formed,
and these circulate from one extremity of the canal to the other *.
11. ON CIRCULATION IN VEGETABLES.
On the 27th of September, MM. Henri Cassini and Mirbel made a
report upon the vegeto- anatomical and physiological observations
presented by Dr. Schultz to the Academy of Sciences. It appears
that a circulation takes place in vegetables, comparable, in some
respects, to that in animals. In fact, when the vessels in a portion
of stem, an inch or two long and two or three lines in width, are
considered, assent cannot be refused to the idea, that a vital juice
exists, and that it passes several times by the same path. But there
is this remarkable difference between the circulation in vegetables
and in animals of a high order, that in the latter there is one point in
which terminate two vascular systems very distinct from each other,
one carrying the blood to the extremities of the body, the other
collecting it and conducting it to its source ; whilst in vegetables we
discover no special point of departure, nor any double vascular
system. Vessels of the same nature form a net-work, of which the
meshes are so many similar circulating apparatus communicating
with each other, so that there is a common motion through them
whilst the parts live together, and a motion proper to each so soon
as they are separated. The discovery of M. Schultz is of the highest
interest for the anatomy and physiology of vegetables ; it enlightens
these two branches of science, the one by the other, and it proves
relations to exist between animals and vegetables, which before
were not even suspected to exist f.
12. NEW METHOD OF MULTIPLYING DAHLIAS.
Some dahlias belonging to M. Jacquemin having been injured by the
wind in the first days of June, and some branches broken off, he
placed them in the ground, in hopes of developing the flower. This
did not take place ; the vegetation languished, but the plants ap-
peared good, and being carefully taken up, were found furnished
* Ann. de Sciences Nat. xxi. p. 92.
f Rev. Ency. xlvii. p. 784.
Natural History, #c. 425
with tubercles. Hence a new means of multiplying these flowers,
and the illustration of a curious physiological fact *.
13. SEAT OF THE SENSE OF TASTE.
The following general experiments and conclusions are from a work
on the seat of this sense by MM. Guyot and Admyrauld. i. If the
anterior extremity of the tongue be inclosed in a very soft, flexible
case of parchment, so as to cover it completely, jelly, and in
general all bodies, may be introduced into the mouth, and crushed
between the teeth without any taste being distinguishable. The same
effect is obtained also by retaining the tongue apart from the cheeks
or teeth ; sapid objects placed beyond its action give no sensation of
taste. The tongue, therefore, is the essential organ of taste ; the
lips, palate, cheeks, and gums have no power of this kind.
ii. Nevertheless, if the tongue be entirely covered, and very sapid
substances be swallowed, a little taste is perceived at the posterior
part of the velum palatinum. If the palatal arch be covered with
parchment, a sapid body produces its ordinary effect upon the
tongue. If a little piece of extract of aloes be fixed upon the end of
a rod, and passed over the palate and the roof of the mouth, it pro-
duces no other sensation than that of touching ; but on the anterior
and upper part of the soft palate there is a small portion of surface,
not haying definite limits, where the impression of sapid bodies is
very sensible ; the back part of the mouth does not partake in this
property, so that this small portion of the palatal vault with the
tongue forms the organ of taste.
iii. If the tongue be covered with parchment, pierced at the middle
of its back surface, sapid bodies applied to the part produce no taste,
until, being dissolved in the saliva, they gain access to the edge of
the tongue. Extract of aloes passed over various parts of the
tongue produce sapid impressions within a space of only one or two
lines at the sides, three or four at the point, and within a curved space
at the back. Hence this part of the tongue and the lateral por-
tions are the especial organs of taste in deglutition; the portion of
the soft palate already mentioned prolongs the sensation f.
14. REMARKABLE CAS'" OF THE RE-UNION OF A DIVIDED PART.
In the Quebec Hospital Reports we find the following case : — A
man in chopping wood cut off the first phalanx of the middle finger.
For two hours after the accident he remained occupied at home.
Although the divided portion of his finger then appeared to be
deprived of vitality, it was determined to follow the plan of Balfour
of Edinburgh, and to attempt to re-unite the parts. The tip of the
finger was fixed to the stump by adhesive plaster, and in three days
union had taken place in two or three parts ; and the extremity of
* Jour, de Pharra, 1830. p. 760. t Bib. Univ. 1830, p. 215.
426 Foreign and Miscellaneous Intelligence.
the finger which had been divided had as much sensation as any
other part of the body. The dressing was continued, and in three
more days the re-union was complete *.
15. SINGULAR EFFECT OF OPIUM.
M. Cavalier states that he had used an enema, consisting of two
ounces of mucilage and a grain and a half of opium. He was
seized with nausea, but "no vomiting ; but having removed the cover
of the night-lamp, the appearance of the light produced vomiting,
and this increased whenever he submitted to the action of light.
He endeavours to explain this curious phenomenon, but leaves it as
obscure as he found it t.
16. MECHANICAL POWERS OF A SPIDER.
The following description of the capabilities and power of a small
species of spider, supposed to be the Aranea extensa, is given by the
Rev. Mr. Turner, in the Transactions of the Northumberland Natural
History Society: it was shown to him by Mr. Mackreth — ' On call-
ing upon him (Mr. Mackreth) the next morning, he brought out a
tumbler glass, which he had inverted on the table over a sprig of
Laurustinus bush, on which he had observed a very small spider.
Supposing that it might want air, he had slipped under the edge of
the glass a small roll of paper. In less than three days, the little
animal had filled the interior^of the glass with minute, almost invisible
threads, by means of which it had raised the sprig into the middle of
the glass ; and, not content with this, had raised also the coil of
paper which by some accident had slipped from under the edge. After
this, it laid, upon one of the upper leaves, a large ball of eggs, and
having thus completed the ultimate object of its existence, it died,
and fell into the meshes of its own web.
4 How this little artist should have accomplished the Herculean task
of raising a weight several hundred times greater than itself, and for
what purpose it should have done this, are questions which may well
deserve consideration.
4 From a comparison of the individual inquestion with the very few
figured by Donovan, it appears to be most like the Aranea extensa,
vol. viii. p. 48 ; and as it is there said to be always found upon trees,
and never upon the ground, this may be the reason why it has exe-
cuted the arduous task of raising the branch, on which it was confined,
to the upper part of the glass J.'
17. WHITE BAIT.
Mr. Yarrell has made several attempts to preserve white bait alive,
of which the following are the results : —
* Baltimore Adviser. Med. Jour. 1830, p. 370. f Med. Surg. Jour. v. p. 335.
J vol. i. p. 42.
Natural History, fyc. 427
1 Several dozens of strong lively fish, four inches in length, were
transferred with great care from the. nets into large vessels (some of
the vessels, to vary the experiment, being of earthenware, and others
of wood and metal) filled with water taken from the Thames at the
time of catching the fish. At the expiration of twenty minutes
nearly the whole of them were dead, none survived longer than half
an hour, and all fell to the bottom of the water. On examination,
tin' air-bladders were found to be empty and collapsed. There was
no cause of death apparent. About four dozen specimens were then
placed in a coffin-shaped box, pierced with holes, which was towed
slowly up the river after the fishing boat. This attempt also failed:
all the fish were dead when the vessel had reached Greenwich. Mr.
Yarrell was told by two white bait fishermen, that they had several
times placed these fishes in the wells of their boat, but they inva-
riably died when brought up the river. The fishermen believe a por-
tion of sea- water to be absolutely necessary to the existence of the
species, and all the circumstances attending this particular fishery
appear to prove their opinion to be correct*.'
18. To RESTORE THE ELASTICITY OF A DAMAGED FEATHER.
A feather when damaged by crumpling may be perfectly restored by
the simple expedient of immersing it in hot water. The feather
will thus completely recover its former elasticity, and look as well as
it ever did. This fact was accidentally discovered by an amateur
ornithologist of Manchester. Receiving, on one occasion, a case of
South American birds, he found that the rarest specimen it contained
was spoilt, from having had its tail rumpled in the packing. Whilst
lamenting over this mishap, he let the bird fall from his hands into
his coffee-cup ; he now deemed it completely lost, but, to his agree-
able surprise, he found, that after he had laid it by the fire to dry,
the plumage of the tail became straight and unruffled, and a valuable
specimen was added to his collection.
19. ORNITHOLOGY.'
At a late meeting of the committee of Science and Correspondence
of the Zoological Society of London, Mr. Vigors, the secretary,
called the attention -of the committee to a gallinaceous group of
America, which supplied in that continent the place of Quails in the
Old World. Of this group, or the genus Ortyx of modern authors,
which a few years back was known to ornithologists by two well-
ascertained species only, he exhibited specimens of six species — viz.,
Ort. Virginianus and Californicus^ which had been the earliest de-
scribed, the former by Linnaeus, the latter by Dr. Latham ; Ort. Ca-
a species lately figured, named in Sir W. Jardine's and
* Trans. Zool, Soc. Lond. p. 14.
428 Foreign and Miscellaneous Intelligence.
Mr. Selby's ' Illustrations of Ornithology,' and Ort. Douglasii, Mon-
tezumcB and Squamatus, which had been described by himself in the
Zoological Journal. In addition to these, he exhibited plates of
three others, of which no specimens were to be obtained in London —
viz., Ort. Macrourus, figured by Sir W. Jardine and Mr. Selby;
Ort. Sojininii, figured by M. Temminck, in the Planches Coloriees
(No. 75) ; and the Ort. Cristatus, figured in the Planches Enlu-
minees (No. 126) of M. Buffon. To these nine described species he
added two others, apparently new to science, and which he charac-
terized under the name of Ort. Neoxenus and Affinis, stating, at the
same time, his doubts whether both might not be females or young
males, of the imperfectly known species of Ort. Sonninii or Cristatus.
Individuals of the four above-mentioned species, viz., Ort. Fir-
ginianus, Californicus, Neoxenus, and Montezumce, had been exhi-
bited in a living state in the garden of the Society, where specimens
of the former three were still alive, having braved the severity of the
last winter without artificial warmth. The Ort. Virginiajius has bred
in this country, and has even become naturalized in Suffolk*.
Indian Birds. — Mr. John Gould, A.L.S., has recently received
from India a large collection of birds, of which he intends shortly to
publish coloured illustrations. Among these are several species,
apparently undescribed, from the Himalayan mountains. The forms
of a large proportion of these birds are capable of being identified
with those of Northern Europe, at the same time that many of the
forms peculiar to Southern Asia and the Indian Archipelago, are
found intermingled with those of the northern regions. Among the
forms similar to the European are three species of Jays, which have
been named Garrulus Laticeolatus, Garr. Bispeculatus, and Garr.
Striatus. The two first of these exhibit a striking affinity to our
well known British bird. The latter species deviates in general
colour and markings from the European species. Although according
in form, and in the former characters, they exhibit a manifest approach
to the Nutcrackers, or genus Nucifraga of Buffon. A new species
of this latter form, Nucifraga Hemispila, is also amongst this collec-
tion, thus adding a second species to a group hitherto supposed to be
limited to o/ne. The collection also contains two species of Wood-
pecker, wh&h have been called Picus Occipitalis and P. Squamatus,
and approach in size and colouring most closely to the European Green
Woodpecker. There is also a species of Hawfinch (Coccothraustes
Jctero'ides}, according accurately with the characters of the northern
species ; and also a small owl (Noctua Cuculoides), nearly allied to
the Noctuce Passerina and Tengmalini of Europe.
Among the forms in this collection, which are peculiar to India,
is a second species of the singular group, which contains the Horned
Pheasant, or the Meleagris Satyra of Linnaeus, and which has lately
been separated by M. Cuvier, under the name Tragopan: it has been
* Proceedings of the Zoological Soc. Lond., p. 2.
Natural History , 8fc. 429
named Tragopan HastingsiL There is also a species of true Phea-
sant (Phasianus albo Cristatus), whicli seems to have been indicated
by former writers from incomplete descriptions or drawings, but
never to have been accurately characterized. A third species is like-
wise added from the collection to the group of Enicurus of M. Tem-
minck, which has hitherto been considered limited in range to the
Indian Archipelago (Enicurus Maculatus).*
The same collection also contains several species of humming
birds ; one of which, previously undescribed, has been called 2Vo-
chilus Loddigesii ; it approaches most nearly to the Tro. Lalandii,
VieilLt
Dr. Andrew Smith, of Cape Town, has informed the Zoological
Society that he has discovered another species of the Macroscelides,
as well as a new one of Erinaceus, and three species of the genus
Otis, together with one of Brachypteryx, the descriptions of which he
purposes to transmit very shortly.
20. ICHTHYOLOGY.
Dr. Smith has transmitted to the Zoological Society a present of
sixteen specimens of fishes, obtained in the neighbourhood of the
Cape of Good Hope ; amongst which are an undetermined species
of Dentex ; a fish allied to Oblada, Cuv., and apparently the type of
a new genus ; a new species of Scomber, Cuv. ; an undescribed
species ofBagrus, Cuv. ; a species of Scyllium, Cuv., probably new
to science; and a second species of the genus Rhina, Schn., which
deviates from the type, by a slight production of the front of the
head, and thus makes an approach to Rhine-bates, Schn. J
21. INFLUENCE OF THE AURORA BOREALIS ON THE MAGNETIC
NEEDLE.— (A. T. Kupffer, of St. Petersburgh.)
1 During the night of the 5th of May, 1830,' says M. Kupffer,
4 whilst I was engaged in observing the hourly variations of the
magnetic deviation, I was surprised to see the needle oscillate
greatly, and at the same time deviate considerably to the east. I
immediately suspected that there was an aurora borealis, and was
particularly gratified on finding my supposition confirmed ; the phe-
nomenon lasted till about two o'clock, when no visible trace of it
was left. During the whole time, I carefully observed the needle,
particularly as I knew that it would be also observed by my corre-
spondents at Nicolajew, Kasan, Berlin, and Freiberg, the 5th of
May being one of the days on which we had agreed to observe
the hourly variations of the needle. The following table contains
the observations at St. Petersburg, Nicolajew, and Kasan ; those
* Trans. Zool. Soc. Lond., p. 7. t Ibid., p. 12.
J Trans. Zool. Soc. Lond. pll.
VOL. I. FKB. 1831. 2 F
430
Foreign and Miscellaneous Intelligence.
made at Berlin and Freiberg are not yet come to, but shall be given
as soon as possible.
Time of
Observ.
Variation of the Deviation.
Time of
Observ.
Variation
St. Peters-
burgh.
of tin- Deviation.
Time of
Observ.
Variation
oftheDev.
n St. Pe-
tersburgh.
St-Peters-
burgh.
Nicolajew.
Kasan.
Nicolajew.
k;i-:m.
7hOO'
42' 00"
23m30
13m555
10h20'
22' 30"
24mOO"
13m195
12h38'
12' 30"
20
42 00
30
585
40
23 00
06
275
40
7 00
40
42 00
26
585
11 00
.42 45
23 96
12ra825
45
Viol.
8 00
42 15
24
565
20
§17 15
24 03
805
13 00
oscil.
20
42 00
30
605
40
'•§ 9 °°
16
545
5
10 30
40
40 15
31
575
12 00
i 4 45
23
475
20
30 00
9 00
32 30
59
645
8
£16 00
—
40
16 15
20
32 00
63
575
20
°20 32
525
40
32 00
80
615
22
15 00
10 00
26 15
77
435
27
18 15
The numbers of this table give only the variations of the deviation,
and are in no definite ratio to the absolute deviation. In the obser-
vations of St. Petersburgh and Nicolajew, an increase in the minutes
and millimetres signifies a western deviation, and vice versa in
Kasan; 1 millimetre is equal to 14' 3".
It will appear from these combined observations, that the magnetic
needle, in all three places, had a very irregular course at the same
time^for, as in St. Petersburgh and Nicolajew, the oscillations began
at about 9 o'clock, and in Kasan at 20 min. past 10, these times will
be found nearly to agree ; as, owing to the different longitude, 9 at
St. Petersburgh corresponds with 9 and 7 minutes in Nicolajew, and
with 10 and 16 minutes at Kasan.
The order of the variation will be seen in a more striking manner
in the following table, in which the observations, which were made
at the same moment (or nearly so), are placed in the same line, and
the millimetre of the observations at Nicolajew and Kasan are
reduced to arcs ; besides, I have taken 42' 00" as the ordinary de-
viation at the three places, which may be done, as the observation
refers only to the relative, and not to the absolute deviation. An
increase in the numbers signifies an increase of the western deviation.
Variation of the Deviation.
Variation of the Deviation.
Time in St.
Petersburgh.
St. Peters-
burgh.
Nicolajew.
Kasan.
Petersburgh.
St. Peters-
burgh.
Nicolajew.
Kasan.
7hOO'
42' 00"
42' 00"
42' 00"
10hOO"
26' 15''
35' 11"
30' 24"
20
42 00
42 00
41 35
20
22 30
31 50
26 38
8 40
42 00
42 35
42 35
40
23 00
31 00
25 37
8 00
42 15
42 52
41 35
11 00
24 45
32 26
26 21
20
42 00
42 00
42 20
20
17 15
31 25
40
40 15
41 52
39 32
40
9 00
29 32
9 00
32 30
37 48
36 03
12 00
4 45
28 32
20
32 30
37 13
37 13
40
32 00
34 45
30 41
From this table it will appear that the course of the needle was
Natural History, Sec. 431
very similar at the three places, but that the variations were far more
considerable at St, Petersburgh than at Nicolajew and Kasan. The
declination will be found to have been —
At Petersburgh. At Nicolajew.
at 9 o'clock. . 9' 30" . . 4' 12"
10 „ . . 15 45 . . 6 49
11 „ . . 17 15 . . 9 34
12 „ . . 37 15 . . 13 28
Total 1°19'45 44' 33"
and, as at St. Petersburgh, on the same day, between 7h. 40 m. A.M. and
2 h. 40 m. P.M., the declination amounted to 17 'J towards the west,
and at Nicolajew to 41'£, the above variation being nearly in the
ratio of two to one, the extent of the irregularity will accordingly
result.
A needle, which at St. Petersburgh performs 300 oscillations in
1108'", makes at Nicolajew the same number within 964"; the ratio
of the squares is 1.3*2, and consequently much less than that of the
variation observed on the 5th of May ; the cause of the irregularity
has accordingly acted more powerfully at St. Petersburgh than at
Nicolajew.
The remark of M. von Humboldt, that irregularities of the above
kind sometimes observe a sort of periodicity, being either followed
or preceded by irregular oscillations at the same hour for some days,
will be found confirmed by the following table of the progress of the
needle at the three places of observation on the 4th of May.
Variation of the Deviation
Time of Observation.
8hOO'
At St. Petersburgh.
39' 30"
at Nicolajew.
23m47"
At Kasan.
13m.555
9 00
39 15
— 45
— .615
10 00
39 30
— 48
— .615
20
37 45
— 77
— .625
40
30 00
— 81
— .615
11 00
28 45
— 81
— .645
20
31 45
— 80
— .465
40
33 00
— 79
— .195
12 00
33 00
— 78
— .175
20
26 15
-^ 96
— .295
40
26 15
24 00
— .245
13 00
24 15
— 00
— .125
20
24 15
23 96
— .155
40
23 15
24 03
12 .900
14 00
21 45
— 10
— .905
20
22 00
— 02
— .925
40
20 15
— 04
— .925
15 00
28 00
— 05
— .765
20
32 45
23 84
— .890
40
37 45
— 76
— .890
16 00
35 30
— 60
— .825
17 00
39 45
— 57
13 .495
18 00
41 15
— 58
— .425
2 F 2
432 Foreign and Miscellaneous Intelligence.
In a note to the above paper, M. Poggendorff states, that on the
same day the needle also experienced great irregularities at Freiberg.
On the 5th of May, at 7 o'clock 20 min. P.M. (8 h. 28' of Petersburgh
time,) the needle was 2' 4 5" eastward ; from this time it moved in an
easterly direction, so as to have reached, at midnight, 21' 9", when
violent oscillations were observed, and the needle rapidly moved
westward, so as to be at 12 h. 15' A.M. 16' 14" west, and consequently
37' 20'' more westward than a quarter of an hour before : this was the
maximum of the westerly deviation — at 12 h. 17' it had diminished
to 12' 0*.
22. DESCRIPTION OF SOME ATMOSPHERIC PHENOMENA. —
(Professor Strehlke, of Danzig.)
On the 29th of last March, 1830, 1 observed the phenomenon of
coloured rings and parhelia, which, as I see from the papers, were
at the same time also seen at other places. It appears, that for some
time before and after the above date, the atmosphere was in a state
peculiarly favourable to appearances of this kind, for, on the 20th of
March, at 5 o'clock P.M., a large coloured areole had formed round
the sun about 45° in diameter ; the sky was covered with numerous
parallel strata of clouds, which appeared to converge towards the
sun, opposite to which they had another point of convergence. The
colours of the ring were dull red internally, and bluish externally.
On the 30th of March, at 10 o'clock P.M., a white halo of 45° had
formed round the moon. On the 9th of April, at 6 o'clock P.M.,
the sun was surrounded by segments of an areole of 45° in diameter ;
on the 10th, at 11 o'clock A.M., it had an incomplete areole, from
the uppermost portion of which a white circle subsequently formed,
inclosing the zenith. But the most striking of all was the pheno-
menon observed on the 29th of March. On the 28th, the wind was
northerly, and in the night it froze ; on the 29th, the wind went
through east to south. The following table exhibits the meteorolo-
gical observations on these two days : —
Barometer at 0.46
Thermometer. above the sea.
28th of March, at 10 o'clock P.M. + 2.0 R. 339"'.41
29th „ 8 „ A.M. 1.1 339 .25 ) Cloudy towards
„ 10 „ „ 4.3 339 .041 east.
„ 12 „ „ 6.2 338 .661 Cloudy towards
„ 2 „ P.M. 8.5 338 .22V south— weak
„ 4 „ „ 9.0 338 .99] sunshine.
„ 6 „ „ 8.0 337 .87)Cloudy towards
8 „ „ 7.5 337 .63 J south.
„ 10 „ „ 8.0 337 .29 Clear.
30th „ 8 „ A,M. 7.0 335 .59
At 3 o'clock 45 min. on either side of the sun, and at the dis-
tance of about 22° from it, there were two parhelia, the outer part of
which was white, the inner red; the horizon was rather cloudy,
* Poggendorff Annalen der Physik und Chemie.
Natural History, 8fc.
433
and the rest of the sky filled with nimbus1. After a few minutes there
appeared round the parhelia B and 0 (Fig. 1.), large segments of
Fig. 1.
Fig. 2.
the circle B D C B, the inner part of which was red ; towards C
the circle was thinner, and not so complete as on the south side
B; and at the uppermost part, D, the arch was not completely
closed : at the same time a white sun was visible opposite to
the real one at about 20° above the horizon. The clouds now
gradually ascended towards the zenith, so as to leave but slight traces
of the arch at B, and to efface C and the northern parhelion com-
pletely. The sunshine was very weak, and the clouds were of a
brownish- red hue, when on a sudden the circle HER appeared at
45° from the sun; it was red internally, green in the middle, and
blue outside. The northern arch was less distinct than the south-
ern, EH; at E also the segment of a circle round the zenith was
visible of about 45°, and there the most vivid colours were seen, from
purple to green and violet. At 4 o'clock, H E B had nearly disap-
peared ; the segment F E I was still visible, and remained so till half
past four, when all traces of the phenomenon had disappeared, and
the sky was equally covered with a cloudy surface.
Two of my friends, who happened to be at a distance from me of
some thousand paces towards the south, saw, besides the two parhelia
B and C, a third in D, and through it there was a segment of about
22° parallel to the horizon ; it was of red colour at the side directed
434 Foreign and Miscellaneous Intelligence.
towards the real sun, and afterwards changed into an undulating
line ; the other appearances were those described above.
On the 1st of December, 1828, at 2 o'clock 25 min. P.M., I ob-
served the phenomenon of which a sketch is given in Fig. 2. The
sun A was, at a distance of about 45°, surrounded by the arches H M
and R N, the inner parts of which were red, and the outer blue ; at
22° from the sun there was another ring, and at its uppermost part an
arch K D T, both of a red colour at the side towards the sun ; be-
sides these appearances, there was a vertical and a horizontal column
of yellowish light, and of the apparent diameter of the sun. At
3 o'clock 35 min., when it began to snow, the phenomenon dis-
appeared.
During one of the nights in August, 1828, I saw, at midnight,
very beautiful coloured halos round the moon, and as I happened to
pass over fields, some of which were covered with fog, and the others
clear, I was surprised to find that the halos ceased to be visible when-
ever I was on a field which was free from fog, but always reappeared
when I came on a field covered with fog. There were three, and some-
times four halos, at small distances from each other, and with very
vivid colours, red being always at the outer circumference ; oppo-
site to the moon there were segments of a white circle. The sky was
clear, and the atmosphere tranquil *.
23. ON THE PRODUCE OP GOLD AND SILVER IN THE RUSSIAN
EMPIRE. — {Alexander von Humboldt)
The yearly produce of the Russian gold and silver mines has lately
been very variously stated ; and as I am afraid that some of these
statements may be attributed to me, I take an opportunity of giving
the following numerical exposition of the fact.
According to official documents, the Russian mines yield an-
nually about 22,000 marks of gold, and 77,000 of silver. In 1828
the produce of gold was 22,256 marks (318 puds, of which 115
were obtained from imperial, and 203 from private mines) ; of silver
76,498 marks (1093 puds) ; and of platina 6570 marks (94 puds) ;
and the respective value was, of gold, 4,896,000 Russian dollars
(700,000/. sterling); and of silver, 1,07 1,000 dollars (153,000?. ster-
ling). The gold mines of the Ural yielded in —
1826 . . . 232 puds.
1827 ... 282 „
1828 291 „
In the first six months of 1829 they gave 142 puds of gold (46
from imperial, and 96 from private mines), and 43 puds of platina.
The total produce of the Ural mines, from 1814 to 1828, is 1551
puds, of the value of about 3,413,OOOZ. sterling ; the last five years
alone yielded 1247 puds.
* Poggendorff's Annalen.
Natural History, 8fc. 435
The annual produce of gold in Europe and in Asiatic Russia
amounts to 26,500 marks of gold, and 292,000 of silver, of which
the Russian empire alone yields 22,200 marks of gold, and 76,500
of silver *.
24. ON THE CHANGE WHICH THE AIR IN EGGS UNDERGOES
DURING INCUBATION. — (Professor Dulk, of Kcenigsberg.)
This philosopher has lately made some analyses of the air in the
large end of the egg at different periods of incubation, and the follow-
ing is the result of his inquiries.
Before incubation, the air contains considerably more oxygen than
atmospheric air, the oxygen in the former being found, at two dif-
ferent experiments, 25.26 and 26.77 ; and that in the latter, on the
day of the experiments, only about 21.0 t.
On the tenth day of incubation the air was found to contain 22.47
of oxygen, and 4.44 of carbonic acid ; the absolute quantity of oxygen
is accordingly nearly the same, but 4.44 of it has united with carbon.
On the twentieth day, the quantity of air in the egg was found to
be nearly eight times as large as before incubation ; the analysis gave,
at four different experiments, —
Carbonic Acid. Oxygen.
9.40
9.23 . . . 17.55
6.19 . . .
8.48 . . . 17.90
where the absolute quantity is the same as in the former experiments,
but the quantity of carbonic acid is increased ; that of the third ex-
periment, being only 6.19 per cent., corresponds, however, in some
degree, with the result of the other analyses, as the chicken had
apparently died a considerable time before the experiment was
made J.
* PoggendorfPs Annalen, 1830. p. 273.
f Though this result is somewhat at variance with that obtained by M. Bischoff,
according to whom the mean quantity of oxygen before incubation is only 23.475,
the experiments of both philosophers agree, inasmuch as both show that the air
of fresh eggs contains more oxygen than atmospheric air.
+ From Schweigger-Seidel's Jahrb. der Chemie und Physik.
JOURNAL
OP
THE ROYAL INSTITUTION
GREAT BRITAIN.
ON THE EMPLOYMENT OF NOTATION IN CHEMISTRY.
By the Rev. W. WHEWELL,
Professor of Mineralogy in the University of Cambridge.
greater part of English chemists appear to have been
hitherto averse from the practice of using a technical and
mathematical notation to express the chemical composition of
bodies ; while in France, Germany, and Sweden, such a nota-
tion is and has been for some time commonly employed. The
disinclination of our countrymen to adopt this invention seems
to arise from a belief that such an instrument is unnecessary,
and from a perception of several anomalies and inconveniences
in the system followed by foreigners. English chemists must
judge for themselves whether they feel the want of such a con-
trivance ; but I have no hesitation in saying, that in mine-
ralogy it is utterly impossible to express clearly, or to reason
upon, the chemical constitution of our substances, without the
employment of some notation or other. Every one who makes
the trial will find that, without a notation, his attempts to
compare the composition of different minerals will be con-
fused and fruitless, and that, by employing symbols, his rea-
sonings may easily be made brief, clear, and systematic.
I have, therefore, endeavoured to remove the gross anoma-
lies and defects with which the foreign notation is disfigured,
and to reduce it, with as little change as possible, to mathema-
tical symmetry and consistency. If this can be done, as I
think it can, with no loss of simplicity and facility, I should
You I. MAY, 1831. 2 G
438 Rev. W. Whewell on the Employment
hope that the system so reformed might obtain general circula-
tion ; since the question undoubtedly is, or soon will be, not
•whether or no we shall employ notation in chemistry, but
whether we shall use a bad and incongruous, or a consistent
and regular notation.
I shall now endeavour to show the necessity and the ad-
vantages of a proper use of symbols in this science, and the
inconveniences of those at present in use on the continent.
In many compounds of two ingredients there is no difficulty
in expressing the composition clearly and simply, by means of
the usual language of chemistry. We have carbonate, 6icar-
bonate and sesquicarbonaie of soda ; where we may observe,
however, that the possibility of expressing the latter compound
in this form, depends upon the accident of there being a Latin
term possessing the signification of one and a half; and that
if we had two atoms and a half of acid, we should be at a loss
how to devise a corresponding term. In the same manner
\ve have sulphurets, 6i'sulphurets,
15 S + 4 A + C-f 6 (7 will represent a body which contains 15
atoms of silica, 4 of alumina, 1 of lime, and 6 of water. If 12
atoms of the silica go with the alumina, and 3 with the lime,
the symbol may stand thus : (12 S + 4 A) + (3 S + C) + 6 q ;
or, what is the same thing, 4 (3 S + A) + (3 S + C) + 6 q ;
in which form it is clearly seen that we have 3 atoms of S with
1 of A, also 3 of S with 1 of C, and that 4 of the former
parcels are combined with 1 of the latter. The same analysis
would also give other results, as 4 (2 S + A) + (7 S + C) + 6 7,
which is less simple, and so less probable than the former, as
the representation of the chemical constitution of the body.
The expression 15 S + 4 A -f C +6(7, the immediate result
of the analysis, may thus be put in various forms ; and these
forms are all identical, in virtue of the common rules of
algebra or arithmetic. I can hardly conceive how any per-
son, at all acquainted with mathematical symbols, can adopt
any other mode of notation than this, inasmuch as no other
can assist us in reasoning on the constitution of chemical com-
pounds. Mr. Herschei long ago employed this mode of
notation for such a purpose. In his paper on the hyposul-
phurous acid (Edinb. Phil. Journ., 1819), he describes the
decomposition of oxynitrate of silver by hyposulphite of lime.
L represents lime ; S, sulphur ; .9, silver ; N, nitric acid ; O,
oxygen. He says, 6 we have, for the atoms present, before
the decomposition,
which afterwards groupe themselves thus : —
that is, one atom nitrate of lime, one of sulphuret of silver, and
one of free sulphuric acid.' In the same manner, in the de-
composition of carbonate of oxide of copper by sulphurous
acid, c denoting copper, he obtains,
2(c+0) +2(8 + 20)
= {(2c+0) + (S + 20)} + (S + 30);
* that is, two atoms of sulphurous acid disengage the carbonic
acid from two of the carbonate, producing one atom of sul-
of Notation in Chemistry* 441
phite of protoxide, and generating one of sulphuric acid/
These seem to me very instructive examples of the use which
may be made of such a method of notation.
Berzelius, however, has lent the weight of his great authority
to a system which possesses none of these advantages, and
which violates mathematical propriety so entirely, that it must
always be disagreeable to see an example of it, for any person
who has acquired the first rudiments of algebra; and this
system has unfortunately been adopted into many excellent
chemical and mineralogical works.
According to the system of which I thus complain, those com-
binations of elements which are supposed to be most intimate ,
are represented by writing the symbols of the ingredients in
the way which in algebra denotes multiplication. Thus A S is
the silicate of alumina ; and when there are several atoms of one
ingredient, the number of these is indicated by the index of the
corresponding letter : thus A S2 is the bisilicate, A S*> or
A2 S3, the sesquisilicate of alumina. And when these primary
combinations are associated so as to form other compounds,
the sign of addition, + , is used. Thus A S2 + C S3 is an atom
of bisilicate of alumina, combined with an atom of trisilicate of
lime. Also a multiplier is, if necessary, annexed to one of
these members. Thus the former example, stilbite, (p. 439,)
would, on this system, be 4 A S3 + C S3 -f 6y. And, by such
formulae, minerals and other bodies are represented by Ber-
zelius and many other writers who have followed him.
The insurmountable objection to such a notation is this :
that it violates all mathematical consistency, and puts out of
sight the identity of different ways of considering the same
analysis. No one can, in the last formula, see any algebraical
reason for supposing it the same with 4 A S2 -f. C Sr 4. 6y,
which it undoubtedly is. No one can readily perceive at once
that the direct result of analysis has in this case been 15 S-f
4A + C + Gq ; which is the fundamental fact. Is there any
obvious connexion between A S + C S3 and A S2 -f C S2,
which are mineralogically identical ? Whereas (A + S) 4.
(C + 3 S) and (A + 2 S) + (C + 2 S) are manifestly the
same quantity. If we adopt such annotation as this of Ber-
zelius, it is almost entirely useless as an instrument of calcula-
442 Rev. W* Whewell on the Employment
tion, besides being singularly awkward in the eyes of every
one at all acquainted with algebra.
The combinations of ingredients which make up compounds
are clearly of the nature of additions) and never can have any
analogy with the multiplication of the numbers expressing the
components ; they therefore ought by no means to be repre-
sented by that combination of symbols which denotes multi-
plication. I cannot account for the adoption of such a mode
of representation any otherwise than by attributing it to the
ambiguity of the words factor and product, which are some-
times used to express the ingredients producing a chemical
compound by their addition, and the compound itself; but
which in algebra properly refer to parts producing a number by
multiplication. Whether or not this double meaning be the
origin of the confusion, there can be no doubt of the exceeding
impropriety, I might say absurdity, of such a kind of symbols.
It is much to be regretted that a system marked with such
blemishes should have been promulgated by Berzelius, whose
great knowledge and deserved eminence gave him more power,
perhaps, than any other chemist possessed, to obtain a Euro-
pean circulation for the vehicle in which his speculations were
conveyed.
I now proceed to the system which I propose to sub-
stitute for this. There can, I think, be no difficulty in its
application. The letters being once fixed upon, which denote
the ingredients to be represented, their combination is to be
indicated by the sign of addition ; and if they be distinguished
into groups, these groups may be marked by brackets, as in
Mr. Herschel's notation. These brackets may often be omitted
without causing any confusion.
I will give an example or two to exhibit the manner in
which a given analysis may be expressed in this notation ; and
also Ihe manner in which, the symbol being given, we may see
what ought to be the analysis.
We have the following analysis of Analcime by H. Rose : — •
Silica . . 55.12 one atom S = 16
Alumina . 22.99 .... A = 18
Soda . . 13.53 N = 32
Water . . 8.27 .... 2 = 9
99.91
of Notation in Chemistry. 443
The soda appears to be the smallest of the ingredients. If we
multiply all the numbers by 2.37, the soda will become 32, or
one atom ; and, as the proportions will not be altered, we
shall have the corresponding numbers of atoms of the other
constituents, by dividing by the weight of one atom of each.
We have thus,
Silica 4 , 130.82 number of atoms r= 8.19
Alumina . 54.49 . . . . ] 3.02
Soda . . 32.09 .... 1
Water . . 19.62 .... 2.18
Since the numbers of atoms must be whole numbers, 8, 3, 1, 2
are the true results, and the formula is8S-f3A + N + 2q.
These elements may be variously grouped. The most pro-
bable arrangement appears to be 3(2 S + A) + 2S + N + 2qt
as the atomic constitution of the analcime analyzed in this
case.
I taker as another example, two analyses of Apophyllite ;
one by Vauquelin, and the other by Berzelius : —
V. B. One atom.
Silica . . 51 52.13 .. (16)
Lime . . 28 24.71 .. (28)
Potassa(K) 4 5.27 .. (48)
Water . . 17 16.20 .. (9)
Fluoric Acid .82 . . (20)
100 99,13
The fluoric acid is probably accidental. If wesuppose thepotassa
to be essential, we must multiply the parts of first analysis by
48
12, and those of the second by r^jy, °r 9.1 1, and then divide
by the weights of one atom. We have thus,
V. Atoms. B. Atoms.
S 612 — 38 474.90 — 29.68 (30)
C 330 — 18 225.11 — 8.04 (8)
K 48 — 1 48 — 1 (1)
q 204 — 22 or 23 147.58 — 16.39 (16)
The second analysis would give 30 S + 8 C + K + 16 7,
which might be grouped thus : 8(3 S + C) + 6 S + K + 16 q ;
and this is given by Berzelius as the constitution of apophyllite.
But Yauquelin's gives us 38S + 12 C -h K + 22 q, which
444 Rev. W. Whewell on the Employment
deviates so far from the other, as to suggest strong doubts of
the soundness of Berzelius's view. The latter analysis may be
putin this form : 11(38 + C + 2 q) + 5 S + C + K ; and the
former in this form : 8 (3 S + C + 2q) + 6 S + K : from which
it appears that by much the largest portion of the mineral may
be considered as 3 S + C + 2q, with an excess of S, and a
small quantity of K. If we consider C and K as isomorphous,
we may, by a rule which, will be given immediately, write the
formula thus, dividing by 9 in one case, and by 13 in the
other (see p. 446.) : —
neither of these differs much from 3 S + C, K, + 2q, |C in one
case, and T^C in the other, being replaced by a corresponding
portion of K. Other analyses must be employed to determine
whether this is the true formula for apophyllite.
It must, I think, be clear to the reader, that this reasoning
could not have been conducted with any tolerable facility or
clearness by employing the symbols of Berzelius. According to
these, the grouping first mentioned would be 8 C S3 + K S6 4.
IGq ; the next might be 12 C S3 + K S2 + 22q : the one in
which K is omitted would be C S3 4- 2q ; and the one last
mentioned would be (C, K) S8 + 2q. There is in these cases
no trace in the symbols themselves of that relation by which
their identity is to be tried, or of their dependence on two
resembling analyses.
I will now exemplify the use of such formulae by writing in
this notation the results of the analyses of several minerals,
which approach to apophyllite in their constitution. These
minerals I will designate as follows : — (1) Apophyllite, (2)
Heulandite, (3) Stilbite, (4) Harmotome, (5) Laumontite, (6)
Analcime, (7) Scolezite, (8) Mesotype. I will also, in addition
to the letters already introduced, use B for baryta (atom = 78).
(1) = 308 + 8C + K + 16?=8(3S + C) + 6S + K)+16?.
(2) = 15 S + 4 A+ C +6? = 4 (3 S + A) +3S-J- C) + 6?.
(3) = 12 S + 3 A + C + 6 q = 3 (3 S + A) + (3S+C) + 6g.
(4) = 12 S + 4A+ B +6 q = 4 (2S +A) + (4 S+ B) +69.
<5) =- 10 S + 4 A ;+ C + 6q = 4 (2S + A)-f (2S-J-C) + 6g.
of Notation in Chemistry* 445
-fN + 2? = 3(2S + A
+ C4-3?=: 3(S+A)
(8) = 6S-f3A+N + 2g=3(S + A)+(
The last column, containing the grouping of the ingredients,
is for the most part according to the views of Berzelius.
If we now wish to compare the quantities of the ingredients
in any case, we have only to introduce the atomic weights.
Thus, for Heulandite, we have
15S + 4A+C +6q
= 240 + 72 + 28 + 54 = 394.
There is no necessity to reduce these quantities of the ingre-
dients to the supposition of 100 for the total, nor to do so with
any given analysis ; since the comparison of the analysis with
the formula may be made with greater brevity, by avoiding such
an intermediate step, and by trying directly the proportionality
of the numbers in the experiment with those in the formula.
In order to compare the constitution of different species, as
for instance those above mentioned, it would be convenient to
reduce the most prominent term, which appears here to be one
with S, to an identity in all, by multiplication or division ; this
process would give the following results : —
S(16)A(18) C(28) g(9) Total.
2 x(2) = 30S+8A+2C + 12g 480 144 56 108 788
30S + 7iA + 2£C + 15<7 480 135 70 135 820
30S+10A + 2£B+15g 480 180 (195,B) 135 990
30S-H2A + 3 C+18 480 216 84 162 942
30S + lliA+3fN + 7^ 480 202£ (120,N) 67* 870
5 X(7)=30S + 15A + 5 C+15g 480 270 140 135 1025
5 X(8) = 30S-H5A+5N+10g 480 270 160 90 1000
As (1) contains the ingredients with somewhat different
relations, the results are not here given for that species.
In some cases it is found that different ingredients are
isomorphous, or may replace each other without altering the
form or species of the mineral. Thus we have Chabasite of
the formula 8S + 3A+ C + 6 y ; and also of the formulae
8S+3A + K + 6^,and8S + 3A + N + 6 ; and a mix-
ture of the two latter kinds, including both K and N. In such
cases a part of the term corresponding to K appears to be potassa,
446 Rev. W. Whewell on the Employment
and a part soda, such portions of the two alkalis entering as to
Ynake up together a proportional ingredient. Thus we may have
aK and -J-N ; and the mineral would then be (9) = 8 S -f
3A + £K + iN + 6q. And4 x (9) = 32S + 12A +
(3K 4. N) + 24(/ : in which, instead of 4 K, we have 3 K
-f- N ; one atom of potassa being replaced by one atom of
soda. In obtaining such formulae from experimental analysis,
the number of atoms of the two isomorphous ingredients must
be added together, including their fractional parts, before we
attempt to compare the atoms of different ingredients. And
in the resulting formula, the symbols of the isomorphous in-
gredients may be written after each other with commas, thus,
(9) Chabasite = 8S + 3A-fC, R, N, + 6 q
= 3 (2 S + A) + (2 S + C, K, N,) + 6 q ;
in which C, K, N, may be read C, or K, or N. And the
composition of different varieties would be —
8S +3A + C -f
S.
A.
Alk.
" 9'
Total.
= 128
54
28
54
264
=: 128
54
32
54
278
= 128
54
48
54
284
8S + 3A+ 3
If such a notation as this were adopted, it would be highly
desirable that there should be a general understanding among
chemists and mineralogists with regard to the letters by which
elements are to be designated ; for we should then be able to
use the formula without preface, with a great gain of brevity
and clearness. The obvious method is to take the initial letter
of the word for the symbol of the element, except when there
are reasons to the contrary. Thus we have A, alumina ; B,
baryta; C, calcia (lime) ; G, glucina; L, lithia; M, magnesia;
N, natron, or soda (for S is wanted to express silica) ; K,
kali, or potassa; S, silica; Y, yttria ; Z, zirconia ; strontia
may be represented by Sr. It may help the memory to observe
that K, L, N, three letters near each other in the alphabet,
represent the three alkaline earths. P is wanted for phos-
phorus ; and K and N are thus used by Berzelius.
In these cases the earth or oxide of the base only occurs ;
the bases themselves, aluminium, barium, &c.; not entering
of Notation in Chemistry. 447
into any common compounds, or into "any that mineralogy is
concerned with. But in the instances of the metals commonly
so called, both the metal itself and its oxide or oxides occur in
composition ; and it would, therefore, be necessary to have
symbols for both these kinds of ingredients. In cases where
we have to reason concerning the quantity of oxygen, it
would be necessary to have a symbol to represent that ele-
ment. Thus, fe representing iron, and o oxygen, we should
have / e + o for the protoxide ; fe + f o for the peroxide.
But, in some very large classes of substances, the metals
exist in the form of oxides only ; and in others, they occur
in the form of acids, as the molybdic, tungstic, chromic
acids. It would, I think, be found more convenient to
have expressions consisting of one term, than of two, in
such instances. I would, therefore, represent the metals
themselves by small letters, as zi for zinc, mn for manganese ;
and the oxides, which occur as bases, and which are ana-
logous to the earths, by the same letters, beginning with a
capital, as Zi, Mn. The oxides of metals could not all be
represented by single letters without confusion ; and I would,
therefore, in order to assist the memory by uniformity, repre-
sent each by two letters, taking the first letter in the name and
some other prominent one. The Latin name should be used,
for the sake of European communication. Thus, we should
have ^e (ferrum) iron, sn (stannum) tin, cu (cuprum) copper,
ag (argentum) silver, au (aurum) gold. These are the symbols
commonly used by those who follow Berzelius. The oxides
would be Fe, S/i, CM, &c.
The bases of the acids might be represented by small letters,
and the acids commonly occurring in minerals by these letters
with accents. Thus we should have s sulphur, sf sulphuric
acid ; c carbon, c' carbonic acid ; p phosphorus, pf phosphoric
acid. In the same manner, arf would represent arsenic acid,
mo' molybdic, tu' tungstic, cr' chromic. The hydracids might
be similarly represented, except, as before, where their consti-
tution was required to be more expressly denoted ; thus JV
would be hydrofluoric acid, cl hydrochloric, cl being chlo-
rine, &c.
Berzelius represents water (aqua) by Aq ; for the sake of
simplicity I have used q.
448 Rev. W, Whewell on the Employment
As examples of the use of this notation, I will take the
minerals in which lead is an ingredient.
Carbonate of lead . P b + 2 cf
Sulphate . . . . P b + 2 *'
Arsenio-phosphate . P 6 + p', ar'
Molybdate . . . P b + 2 mo'
Tungstate . . . P 6 + 2 tu'
Chromate . . . P b + cr'
Murio-carbonate . Pb + 2cf + Pb + 2 cl (Berzelius)
Sulphate-carbonate . P&-f-2c' + P6 + 2s'
Sulphato-tricarbonate
Sulphuret . . . .
The preceding notation is intended principally for the pur-
poses of mineralogy ; in the calculations of chemistry it would
be necessary to have some additional contrivances. Thus, it
would be proper, as I have already observed, to indicate the
mode in which both the oxides and the acids are formed from
their bases, by the addition of definite portions of oxygen.
For this purpose let o represent an atom of oxygen ; also
let h be an atom of hydrogen ; and we shall have the fol-
lowing symbols : —
fe + o = protoxide of iron (Fe),fe -f--f o = peroxide (Fes.)
mn + o = protoxide of manganese (Mw), mn + -|o = deut-
oxide, (M?w) run -\- 20 =: peroxide (Mwi).
mn + 3 o =s manganesious acid, mn + 4 o = man gauesic.
ar-\- f o = arsenious acid, ar + f o = arsenic acid (a/)
s + h = sulphuretted hydrogen, s -f- 2 o = sulphurous acid, 5 +
3 o = sulphuric (s/).
fl + h = hydrofluoric acid (fl1 ) cl + h = hydrochloric acid
It may occur as an objection to this system, that we have thus
two ways of representing the same element, as/e + o and F e
for protoxide of iron, s + 3 o and sf for sulphuric acid, fl + h
and fl for hydrofluoric acid. But it is to be observed, that
the former symbol in each of these cases is the regular and
systematic one, and the latter is merely an abbreviation, which
may be employed for the sake of convenience, and which, I
believe, in the cases of minerals it will generally be most simple
to use. We may make such abbreviations for all the oxides
of Notation in Chemistry.? m 449
by repeating the second letter of the symbol for each additional
atom of oxygen, and adding s (semissis) for half an atom.
Thus Mn, Mns, Mrw are the protoxide, deutoxide, and pe-
roxide of manganese.
In the notation of Berzelius, the atoms of oxygen are indi-
cated by dots placed over the symbol of the base. Thus,
fe, fe are the protoxide and peroxide of iron, which he con-
siders as having two and three atoms of oxygen respectively.
This notation is compact and simple, but it is not consistent
with algebraical rule, so far as the oxygen is concerned ; and I
conceive that, if this element be explicitly expressed, it ought
to be dorie in the manner I have recommended above, fe+2o,
/e+3o, &c.
The employment of different notations for the two purposes
of expressing respectively mineralogical analysis, and the ulte-
rior analysis with which chemistry is concerned, has been found
so far convenient, that it has been introduced into general use
by Berzelius and his followers. They have, however, embar-
rassed their method with rules and inventions, which very often
make the relation between the two sets of symbols obscure and
perplexed. Thus it is by no means, at first sight, obvious that
the following pairs of symbols are identical, though the writers
of whom I speak make them to be so : —
M3 Si4 = MSi*, L Si* = LSi9,
F» Si =/• Si, Feisi = FsSi.
The number of atoms of oxygen which we must suppose to
combine with the base in given substances is, in some cases,
dependent on convention, and in others is not yet accurately
determined. Hence, the view taken of many substances by
Berzelius and by English chemists is different. Thus, he con-
siders silica as a combination of 1 atom of base with 3 of
oxygen, and writes it S i. Most English chemists consider it
as 1 atom of base and 1 of oxygen = si + o, for which we
may write the abbreviation S.
I will now add the list of both the kinds of symbols which
I have recommended, and which I hope the preceding obser-
vations have shown to be mathematically consistent and che-
450
Rev. W. Wliewell on the Employment
mically useful. I have used the atomic composition adopted
by Dr. Turner in his Chemistry.
Jca = potassium
faz + o = K = Potassa.
na = sodium
na + o = N rz Soda.
li t= lithium
Zi + o = L = Lithia.
ba = barium
6« -f- o = B = Baryta.
sr = strontium
sr + o = Sr = Strontia.
ca = calcium
ca + ° ^ C = Lime (calcia).
TTiazz magnesium
tna + o = M = Magnesia.
zi = zirconium
zi 4- o ~ Z ~ Zirconia.
g-£ = glucinum
g/ -j- o = G = Glucina.
al zz aluminium
al + o zz A = Alumina.
si = silicium'
si -f- o = S = Silica.
mn zz manganese'
77171 +0= Mn zz Protoxide.
77171 -f- -| o = M?is =r Deutoxide.
77171+20 r= M?M r= Peroxide.
77171 + 3 o = MM = ManganesiousAcid.
77171 + 4 o = 77i7i' = Manganesic Acid.
fe = iron
fe -f- o = Fe = oxide.
^/e + f o =: Fes rr peroxide.
21 = zinc
2/ -f- o = Zi = oxide.
cd = cadmium
cd + o = Cd = oxide.
s/i = tin
S7i + o = Sn = oxide.
sn + 2 o =5 SWTZ = peroxide.
ce zz cerium
ce -f- o r= Ce = oxide.
ce + |- o = Ce5 = peroxide.
cb = cobalt
cb + o = Cb t= oxide.
c6 H- -J o = Cfts = peroxide.
7ii = nickel
Tii + o = Ni = oxide.
ni -j- |- o = NM = peroxide.
bi = bismuth
6i + o = Bi = oxide.
ii r= titanium
ti -f o = Ti r= oxide.
CM = copper
cu -f- o = C?i = oxide.
cit + 2 o = Cuu = peroxide.
ur = uranium
ur + o r=: Ur = oxide.
t/r -f- 2 o zz Urr = peroxide.
J9& s=: lead
pb -J~ ° "-^ •^'^ :— " oxi^6-
p6 + f o = P6s = deutoxide.
. pb + 2 o = P66 = peroxide.
hg = mercury
/sg + o = Hg- zz oxide.
fig + 2 o s= H^ ~ peroxide.
of Notation in Chemistry.
451
ag = silver
flg + o = Ag- = oxide.
au = gold
CM -f o = Ku = oxide.
pt == platinum
^;^ -j- o t= P^ = oxide.
pd = palladium
^?d + o =: Pc^ r= oxide.
z> =5 iridium
r^ = rhodium
r£ + o =^ RA = oxide.
rli + J o =: R/w r= peroxide.
cm = osmium
cr =5 chromium
cr -f- o = Cr = oxide.
cr + f o = cr' = chromic acid.
mo = molybdenum
mo + o = Mo = oxide.
mo -J- 2 o = Moo = deutoxide.
wo + 3 o = mo' = molybdic acid.
iu e= tungsten
tu -f- 2 o =2 T?m = oxide.
ta -f 3 o = tu' s= tungstic acid.
cm r= columbium
a?« r= antimony
«7i + o =: oxide.
aw + J o — deutoxide.
ar —Tirsenic -
ar + ^ o = c?*N = arsenious acid.
cr -f- ^ o = flr' r= arsenic.
p == phosphorus
^? -f- 1 ° = px = phosphorous acid.
jP ~h f ° = #' == phosphoric.
s == sulphur
s + o = hyposulphurous acid.
5 -f 2 o = sx = sulphurous.
s -f- 3 o = s' S3 sulphuric.
se = selenium
se 4- 2 o =r se% =: selenious acid.
«e + 8 o z=. sef = selenic.
te = tellurium
^e + o = oxide.
6 = boron
6 + 2 0 =6' = boracic acid.
c = carbon
c -j- o = cv r= carbonic oxide.
c + 2 o = c/ = carbonic acid.
n = nitrogen
TI+O = oxide.
?i -f- 2 o == deutoxide.
n + 3 o = hyponitrous acid.
?i + 4 o rr nx = nitrous acid.
n + 5 o = n' = nitric acid.
n + 3h =Am = ammonia.
^ r= fluorine
Jl -{-h -=Jl' zi hydrofluoric acid.
c/ = chlorine
c/ + £ = cZ' = muriatic acid.
io cs iodine
io + h = io1 = hydriodic acid.
In this table, the whole of the last vertical column of
452 Rev. W, Whewell on the Employment
symbols is to be looked upon as consisting of mere abbrevia-
tions, which are not indispensably necessary : they need not
be used in chemistry, but they are generally convenient in
expressing the constitution of minerals, as they make the for-
mula shorter and more simple. In chemical investigations, it
would generally be better to use the other or systematic sym-
bols. In these it will be observed that none but small letters
are used (capitals and accents being confined to the abbreviated
symbols). All metallic elements are represented by two
letters : the single letters used are, 6, c, h, n, o, p9 s. There
is, I think, no part of the system in which any ambiguity can
occur : thus S and si refer to silica and its base, st sv, s' to
sulphur and its acids: C, ca, lime and its base; c, c\ c', carbon
and its acids : CM, Cu9 cb, Cb, cr, cr, &c. various metals and
their combinations; N, na, soda and its base; n, wx, ri, nitro-
gen and its combinations. The use, however, of the grave
accent, as s\ rt, &c. for the sulphurous, nitrous, &c. acids,
would be almost superfluous, as these do not occur in
minerals.
As an exemplification of the above symbols, take the con-
stitution of Alamandine and Melanite, according to Beudant —
Alamandine = (2 S -f 3 Fe) + 2 (S + A).
=r (2s7+~o + 3/7+~o) + 2 (si + o + al + o)
= 4 si + 3fe + 2 al + 9 o.
Melanite = (2 S + 3 C) + 2 (S + Fe?).
= (2 w + o + 3 ca + o) + 2 (si + o + fe + f o)
= 4 si -f- 3 ca + 2fe -f 10 o.
The difference of these two expressions in the quantity of
oxygen disappears according to the views of Berzelius, who
considers S as si + 3 o9 C as ca + 2 o, Fe as fe + 20, Fes
as/e + 3 o, A as al + 3 o. We have thus —
Alamandine = (2 si + 3 o + 3/e + 2o) + 2 (si + 3 o+a/+3o)
Melahite = (2 si -f 3 o + 3 ca + 2 o)+(si + 3o + fe, +3o
= 4 si + 3 ca + 2fe -f 24 o ;
and the two expressions are now analogous.
The notation of Berzelius has already been widely diffused,
and much valuable information has been embodied in it* espe-
of Notation in Chemistry. 453
cially on the subject of mineralogy ; yet the objections to it are
of the most weighty character. Its formulae are merely un-
connected records of inferences which are in some degree arbi-
trary ; the analysis itself, the fundamental and certain fact
from which the inferences are made, is not recorded in the
symbol ; and the connexion between different formulae, the
identity of which is a necessary and important circumstance,
can be recognised only by an entire perversion of all algebraical
rules. In the system which I have proposed, the fundamental
analysis is the simplest shape of the formulae ; the various in-
ferences from it are made by the most obvious changes, and the
identity of these with the analysis, and with each other, is evi-
dent on the face of the notation. One method, by a misappli-
cation of mathematical symbols, gives us a sign which can
only record an opinion possibly false : the other represents
simply what is certainly true, and enables us to reason from
the fact tp all its possible inferences, without considering any-
thing except the notation itself. It will not long be pos-
sible to dispense with some such instrument in this country ;
and I should hope that what I have said may tend to induce
our chemists to purify and improve the foreign system, before
it is admitted to a familiarity and circulation among us, which
may make the correction of its faults a task of great difficulty
and inconvenience.
Trinity College, Cambridge,
March 15, 1831.
ON THE PLANT INTENDED BY THE SHAMROCK OF
IRELAND.
BY I. E. BICHENO, ESQ., F.R.S., SEC. L. S., &c.
[Read at the Linnean Society.]
rpHE festival of St. Patrick has been so long recognised by
-"• those who traverse the streets of this great city, by the
clover they see in the hats of the Irish, that any one who
should entertain an opinion that this plant is not the original
emblem of Ireland, will be thought to have no ground for
VOL. I. MAY, 1831 2 H
454 Mr. Bicheno on the
differing from the established belief; yet, I think I am in a
situation to prove, by abundant testimony, that the Trifolium
repens is not that shamrock of the Irish nation, nor any other
clover, but that the wood-sorrel, the Oxalis acetosella, is the
plant originally intended. As it is a point of some curiosity, I
shall venture to lay the evidence before the Linnean Society.
It would seem a condition, at least suitable, if not necessary,
to a national emblem, that it should be something familiar to
the people, and familiar, too, at the season when the national
feast is celebrated. Thus, the Welsh have given the leek to
St. David, being a favourite oleraceous herb, and almost the
only green thing which is to be found in Wales at the season
of his feast ; the Scotch, on the other hand, whose feast of
St. Andrew is in the autumn, have adopted the thistle (pro-
bably the Carduus lanceolatus) , a plant most abundant at that
period of the year. Our own patron, St. George, is a saint
who has fallen so much to the leeward with us, that I do not
derive any assistance from him ; and I am not aware that his
warlike temperament was ever represented by a plant or
flower.
If the national emblem may be expected to be seasonable
and familiar, the Trifolium repens is not a happy choice ; for
its leaves are scarcely expanded in the middle of March, and
it produces its flowers in the summer, — its great merit in agri-
culture being to produce herbage during the droughts of sum-
mer and the autumnal months. Hence even in London, about
which the earliest cultivation is found, we see in the hats of
the meri Hiberni very starved specimens of the white, or
Dutch clover, and sometimes the Medicago lupulina, and even
chickweed and other plants substituted for it. But there is a
still greater difficulty with regard to its being of common
occurrence. None of the trefoils are naturally abundant in
Ireland, but have become so by cultivation. The Medicago
is pretty extensively sown ; and the Trifolium repens} though
now neglected by the farmer, has a wonderful propensity to
diffuse itself in improved countries, and is by no means of fre-
quent occurrence in wild uncultivated places. It is one of
those plants which the Americans describe as coming in with
cultivation. It is not a favourite, or rather there is a prejudice
Shamrock of Ireland. 455
against it, in America, yet it has completely naturalized itself
in every dry pasture of the old states. We know that the tre-
foils are not of very ancient standing as cultivated plants in
England ; and that they were introduced into Ireland in the
middle of the seventeenth century, of which a particular
account is given in Master Hartlib's Legacy of Husbandry.
The term Shamrock seems a general appellation for the
trefoils, or three-leaved plants. Gerard says the meadow tre-
foils are called in Ireland shamrocks ; and I find the name so
applied by other authors. The Irish names for Trifolium
repens are seamar-oge, shamrog, and shamrock. ' This plant,'
says Threlkeld, who printed the earliest Flora we have of the
country, «« is worn by the people in their hats upon the 17th
day of March, yearly, which is called St. Patrick's day ; it
being a current tradition, that by this three-leafed grass, he
emblematically set forth to them the mystery of the Holy
Trinity. * However that be, when they wet their Seamar-oge9
they often commit excess in liquor, which is not a right keep-
ing a day to the Lord, error generally leading to debauchery/
The Trifolium pratense is called, in the statistic report of
the county of Tyrone, the horse shamrock, evidently from its
si/e. Threlkeld's and Keogh's Irish names (which are the
best authority) for the Oxalis acetosella are so like those
which are given to the Trifolium repens, both in spelling and
sound, that they must be the same. Thus we have Threlkeld's
names Scumsog and Samsog ; while Keogh gives for the same
plant Samsogy and Shamsoge.
In Gaelic the name Seamrag is applied by Lightfoot to the
Trifolium repens ; while, in the Gaelic Dictionary, published
by the Gaelic Society, under the word Seamrag9 many plants
are mentioned to which this word is prefixed as a generic
term, as Seamrag chapuill, purple clover ; Seamrag chre, male
speedwell ; Seamrag nfhuire, pimpernel!. I conclude from
this, that shamrock is a generic word common to the Gaelic
and Irish languages, and, consequently, not limited to the
Trifolium repens.
The poets, too, have made use of the word, as I find in a
quotation made in the Gaelic Dictionary, from an ancient
Gaelic poem in Smith's collection,
2 H 2
456 Mr. Bicheno on the
.. Air an t seamrag's agus an ne6inean
Santig aisling na h-oige a' m' choir.
The translation of which I find to be, « On the shamrock, and
amidst the daisies, when the dream of youth shall come unto
me.' Now I would suggest, that either the word shamrock
here employed is not the Trifolium repens, as is thought, and
which its connexion with the daisy would lead me to infer ; or,
the poem is not so ancient as has been supposed ; for the
Trifolium repens, probably, nay almost certainly, was not
common in Scotland before the middle of the seventeenth
century.
In the early Irish authors we find the shamrock mentioned
incidentally. I will take the liberty to quote a passage from
Spenser's View of the State of Ireland, to prove that it was a
plant eaten by the Irish, which is very unlikely to have been
the case with any of the clovers. It is a description of the
state of the poor Irish during the great Desmond war in
Elizabeth's reign : — ' Out of every corner of the woods and
glynnes,' says he, ' they come creeping forth upon their
hands, for their legs could not bear them, they looked like
anatomies of death, they spoke like ghosts crying out of their
graves, they did eat the dead carrions, happy where they could
find them, yea, and one another soon after, insomuch as the
very carcases they spared not to scrape out of their graves ;
and if they found a plot of watercresses or shamrocks, there
they flocked as to a feast for the time, yet not able long to
continue there withal, that in short space there were none left,
and a most populous plentiful country suddenly left void of
man and beast ; yet sure in all that war there perished not
many by the sword, but all by the extremity of famine, which
they themselves had wrought.' That shamrocks were eaten,
appears from various other authors, as in the following couplet
from Wythe's Abuses Stript and PThipt, 8vo. Lond. 1613,
p. 72, quoted in Brand's Popular Antiquities, by Ellis, p. 90 :
And, for my clothing, in a mantle goe,
And feed on sham-roots, as the Irish doe.
So the author of the Irish Hudibras, printed 1689, says —
Shamrogs and watergrass he shows,
Which was both meat, and drink, and close.
Shamrock of Ireland. 457
And again, p. 31 —
Thus hotly they pursued the scent,
Cramming their gorges as they went ;
Until they crept the very weed,
Where every day they used to feed.
Nees, when the shamrog he did spye,
Cries out, I have it in my eye,
Is vid me fait. And so he run,
To bring the presents to the nun.
My next quotation shall be from Fynnes Morrison, who
went over to Ireland, in 1598, with the Lord-Deputy Mount-
joy, to quell the Earl of Tyrone's rebellion ; by which it will
appear that the shamrock was not only eaten, but that it was
a sour plant. It may also be inferred, as it was eaten after
the winter stock of provisions, that it was a spring plant.
( Yea, the wilde Irish in time of greatest peace impute covet-
ousnesse^ and base birth to him, that hath any corn after
Christmas, as if it were a point of nobility to consume all
within those festival dayes. They willingly eate the hearbe
shamrocke, being of a sharp taste, which, as they run and are
chased to and fro, they snatch like beastes out of the ditches.'
If the shamrock should be proved, by a more diligent search
into the old authorities, to have been a wood plant, this cir-
cumstance would materially corroborate the view I have taken,
as the Trifolium repens is never found in such situations.
The only authority for the fact, I have yet discovered, has
been pointed out to me by my friend, Mr. E. T. Bennett, in
the Irish Hudibras, where the plant is twice mentioned as
being found in a wood : —
Within a wood, near to this place,
There grows a bunch of three-leaved grass,
Call'd by the boglanders sham rogues,
A present for the queen of shoges (spirits).
p. 23, and again at p. 30.
Nor is it difficult to account for the substitution of the one
plant for the other. Cultivation, which brought in the trefoil,
drove out the wood-sorrel. The latter, though now not com-
mon, was, doubtless, an abundant plant as long as the woods
remained ; but these being cut down, partly by the natives to
supply their wants, and partly also by the government to pre-
vent their enemies from taking refuge in them in the wars, the
458 Professor Renwick on
commonest plant became the scarcest, and it was more easy
to obtain that which was cultivated.
Upon the whole view of the case, I apprehend it can hardly
be doubted, that the Oxalis acetoselta is the original shamrock
of Ireland. It possesses, in the first place, all the qualities to
recommend it as appropriate for the national feast, and is
even more beautifully three-leaved than the clover. It is
abundant, and comes at the proper season, being one of the
earliest plants, and pushing forth its delicate leaves and
blossoms with the first spring. It was also eaten ; while its
flavour, too, answers exactly to the description of Morrison,
which is a great point to assist in fixing its appropriation ;
and to the old Irish, who lived chiefly upon flesh, it must have
been a most acceptable diet. It would be impossible to find
any plant throughout the vegetable kingdom better entitled to
become national ; and I think it cannot be questioned, that
St. Patrick, who is said by Gibbon to have been descended,
and to have derived his name, from the patricians of Rome,
exercised a good taste, worthy his noble birth, when he
selected so beautiful an emblem for his favourite island.
ON THE EARLIEST EPOCH OF EGYPTIAN CHRONOLOGY.
[Being an Extract of a Letter from JAMES RENWICK, LL.D., Professor of
Natural Experimental Philosophy in Colombia College, New
York, to Captain EDWARD SABINE, R.A., F.R.S.]
a former occasion, I mentioned to you that I had under-
taken the examination of the Hieroglyphic System of
Young and Champollion, with a view to the discovery of the
epoch whence the colonization of Egypt may date, along with
the origin of its history. I am now enabled to transmit to you
a more full exposition of the views I entertain on this interest-
ing subject. These are, in this form, at your service, to make
such use of them as you may think proper.
As you may recollect, I conceived that I had, by means of
four distinct and independent methods, arrived at a close
coincidence in the date, whence we are to date the earliest
traditions of the Egyptians. These are as follows — viz. :
I. The principle upon which it is stated by ancient authors,
that the commencement of the agricultural and astronomical
Egyptian Chronology. 459
year of the Egyptians was determined ; a principle that was only
true at a remote period, and has since ceased to be applicable.
II. From the length assigned to the Sothic Cycle, at the end
of which the beginning of the civil and astronomic years returned
to the same day. A length which was given by the ancient
authors is correct only between certain epochs, and was not
true at those which were more remote, nor consistent at any
time with the true length of the tropical year.
III. From the groupeof Zodaical stars assigned as the place
of the sun, at the beginning of the agricultural year of the
Egyptians, excluding all dates previous to his being in this
groupe at the time of the rising of the Nile.
IV. From a version of a remarkable passage in Herodotus;
a version in which I had the aid of my learned colleague, Pro-
fessor Moore, and which I, at the time, believed had the
merit of ojiginality. You, however, inform me, that it has
been construed in a similar manner by St. Martin, and this
coincidence adds no small weight to the views 1 at that time
supposed I entertained unsupported.
I. Before the introduction of calendars founded upon astro-
nomical tables, it was the universal custom of the nations of
antiquity to regulate their agricultural labours by the heliacal
rising of remarkable stars. In the Egyptian climate, the whole
of these were also determined by the phenomenon of the rising
of the Nile. The country, which, without this happy provision
of nature, would be absolutely desert, a mass of barren and in-
hospitable sand, and which suffers from famine when the inun-
dation does not reach its mean height, is annually restored to
cultivation by its means, and rendered one of the most fertile
regions of the earth. The moisture with which the inundation
charges the earth is long kept up by abundant dews, that the
alternating excesses of solar and terrestrial radiation, during the
day and night, give rise to ; but, at the approach of the summer
solstice, these naturally lessen, and, finally, cease altogether,
vegetation loses its support, and the fertile fields assume the
appearance of a sandy waste. Hence, the rising of the Nile is
watched for, with the most intense expectation, not merely on
the neighbouring shores of the river, but on the furthest fron-
tier of the country, whence the joyful tidings are transmitted
with all possible celerity. Hence, too, the astronomic pheno-
460 Professor Renwick on
menon, supposed to coincide with the overflow of the Nile,
became an observation of the greatest interest; and the star, in
whose heliacal rising it consisted, passed into an object of worship.
Of this fact, and of its reason, many authorities may be
adduced, even from the few authors that have come down to us,
who have treated directly cr incidentally of the affairs of Egypt.
The star was the Dog Star, the ' AGT^XVUV of the Greeks, the
Sothis and Soth of the Egyptians; a star sacred to the goddess
Isis, and probably worshipped itself under the form of Anubis —
Oppida tota Canem venerantur. — Juvenal.
From the rising of this star they were accustomed, according
to Horus Apollo, to predict the occurrences of the follow-
ing year. So also in Cicero de Divinatione, lib. i. : —
" Eos accipimus ortum caniculse diligenter quotannis solere
servare, conjecturamque capere (utscribitPonteius Heraclides),
salubris ne, an pestilens annus futurus sit." Likewise in
Porphyr. de Nymph., as quoted by Sir John Marsham : —
" ^Egyptiis principium anni, non Aquarius, ut apud Romanes,
sed Cancer. Nam prope Cancrum est Sothis, quam Graeci
Canis-Sidus dicunt, Neomenia autem est ipsius Sothidis ortus,
quae generationis mundi ducit initium." By the testimony of
Censorinus, we find that the epoch of Egyptian chronology
was the coincidence of the first day of the vague year with the
rising of Sirius; and we find, in Diodorus Siculns, a tradition
of the priests, by which the rising of the Nile is connected with
the appearance of Sirius. It is, however, useless to multiply
citations to illustrate the admitted fact, that the heliacal rising
of Sirius was considered as corresponding with the commence-
ment of the inundation of the Nile.
It may then be concluded, that, at the time the wants
and interests of the first settlers of Egypt led them to endea-
vour to connect the most interesting period of their seasons
with astronomic phenomena, these two phenomena were so
near to each other, that the appearance of the star might be
taken as the sure prognostic of the rise of the river. This, how-
ever, is far from being the case at present ; the inundation has
already reached a considerable height before the star becomes
visible, and the latter can no longer serve as an astronomic
presage of an event that occurs subsequent to it.
The rising of the Nile is gradual, and is first to be remarked
Egyptian Chronology. 461
at the higher parts of the stream, and hence it is unnecessary
that the astronomic forerunner should be actually prior to the
beginning of the inundation. This is more particularly the
case in central and lower Egypt, where, even if the rising of
Sirius did correspond with the first swell of the Nile on the
frontiers of Nubia, some days must elapse before the connexion
would be detected.
We may, therefore, consider that we are warranted in
ascribing to a system, in which the two appearances, however
dissimilar in cause, were considered as identical in point of
time, an origin no farther distant than the period in which
they were actually contemporaneous. The rise of the Nile,
growing out of the tropical rains, follows in its law the tropical
year, and recurs, on an average, on a fixed day of our
present calendar. The heliacal rising of a star, on the other
hand, is affected by the precession of the equinoxes, and, in
consequence, recurs later every year than it did the preceding.
But it is not governed by the sidereal year exactly ; for, as the
declination of stars alters, as well as their right ascension, the
interval between the successive risings of the same star will not
have a constant length corresponding to the last named period ;
but it will vary, being sometimes longer, and sometimes
shorter; in respect to Sirius, this interval, as we ascertain
from the calculations of Larcher, which have been confirmed
by Biot, was, for from twenty to thirty centuries before the
Christian era, exactly 365J days, being greater than the
tropical, and less than the sidereal year. The difference, then,
between the real length of the year marked by the star, and
that determined by the rising of the Nile, will be the same as
that known to exist between the Gregorian and Julian calen-
dars, or three days in 400 years.
Now, the rising of the Nile below the cataracts, although
usually referred to the solstice, actually occurs, at the isle of
Philae, at an average, on the 25th of June. This, therefore, is
the earliest day to which we are warranted in referring the
observation of the rising of Sirius, upon which the coincidence
of the two phenomena is founded ; while we are almost autho-
rised to place it even later, as the star would otherwise have
been seen at Thebes or This, before the increase of the Nile
could have been perceptible.
462 Professor Renwick on
The heliacal rising of Sirius is fixed by Censorinus as having
happened, in the year 139 A.D., on the 20th of July ; and the
truth of this statement is amply confirmed by astronomic calcu-
lation. Between this date and the 25th of June there intervene
twenty-four days, which is a difference that will take place
between the Julian and Gregorian calendars in 3200 years.
The observation cannot, therefore, be carried back farther than
3060 years before the Christian era ; and if made by simple
inspection of the river, instead of being referred to the marks
upon a Nilometer, may have occurred 200 or 300 years later,
particularly if made at This, instead of being observed at the
frontiers of Nubia.
This is the first of the investigations by which I conceived
myself warranted in restricting the earliest settlement of a
colony in Egypt to about 2800 years before the Christian
era.
II. The year of the Egyptians differed from that of any
nation of antiquity whose records or traditions have come down
to us, Herodotus informs us*, * That the Egyptians were the
first of men who invented the year, and divided it into twelve
months ; and this they found out by means of the stars. In
this they seem to have acted more prudently than the Greeks ;'
for the latter ' intercalated every third year, but the Egyptians
annually add five days to the twelve months of thirty days
each.' Diodorus Siculus gives us another form of the yearf:
* They say that they are the most ancient of nations ; and that
philosophy and astronomy were by them invented, the situation
of their country assisting them to ascertain more clearly the
rising and setting of the stars. The months and years are,
however, arranged by them in a peculiar manner : for adapt-
ing their days, not to the motion of the moon, but to that of
the sun, they attribute thirty days to each month, but after each
twelfth month they intercalate five days and a quarter ; and
thus complete the circle of the year.'
This apparent discrepancy is explained by another ancient
author^ : — * For they were desirous that the festivals of the
gods should not be represented always at the same season, but
they wished them to revolve through every period of the year ;
* Lib. ii. cap. 4. t Lib. i.
* Geminus, as quoted by Marsham and Witsius.
Egyptian Chronology. 463
that the same festival might at one time occur in summer, at
another in winter; and again in spring, and in autumn. On
this account they do not insert the quarter of u day, in order
that the religious solemnities may retrograde.'
Thus we find the earliest authorities citing two different
years, which are, as will be seen, reconciled by one of later date.
The first of these was such that it circulated throughout the
seasons, and is hence called ( vague ;' the second was supposed
to coincide with the course of the sun. A year of 365J days,
however, does not coincide with the tropical year, nor had the
true length of the latter been discovered by any people of remote
antiquity. The close coincidence that the Egyptians attained
to, cannot be considered as due to observations of the sun ;
for it is obvious, from various circumstances, that their astro-
nomy did not go this length, but arose from the return of the
heliacal rising of Sirius, which, as has been seen, during the
flourishing periods of the Egyptian kingdom, occurred at exact
intervals of 365 £ days. The same observation gave them ori-
ginally a year of 365 days, for the discovery of which but few
years would have been sufficient, and afterwards enabled them
to ascertain its error.
How they reconciled these two species of years in their chro-
nology we learn from Strabo : — ' The Thebans, particularly the
priests, are said to be astronomers and philosophers $ it is their
custom to reckon the days, not by the course of the moon,
but by that of the sun. They annually add five days to their
twelve months of thirty days each ; but since a certain fraction
of a day exceeds the complement of the whole year, they make
a period of such a number of years, that the exceeding frac-
tions may make up a year. '
Such a period would be equal to 1460 Julian or 1461 vague
years, and it formed the famous Sothic period of the Egyptians,
the Cynic cycle of the Greeks, and the Canicular of Latin
authors. It took its origin when the first day of the vague
Egyptian year coincided with the rising of Sirius, and closed
when the same coincidence again occurred. This coincidence
did occur, and the cycle terminated in the year 138 A.D. The
origin is, therefore, to be found in the year 1322 before our
era. Between these dates it was used as an ordinary mode of
464 Professor Renwick on
computation, by which the vague year was reconciled to the
changes of the seasons ; this is evident, from a quotation from
Manet ho, taken by Marsham from Jamblicus, and from the
ancient chronicle, quoted by Syncellus, in both of which the
great period of 36,525 years, or twenty-five generations of the
Cynic Cycle, is referred to. If used at all, it must have been
employed as early as the commencement of this cycle, and of
its use the contemporary testimony of Manetho is conclusive
evidence.
The Egyptians, I think it is evident, had made but little
progress in the astronomy of observation. The names and
places of separate stars, and of several groupes, were known
to them, and the year of 365 J days. Much further they do
not appear to have gone, as Ptolemy was compelled to have
recourse to Chaldean records for the facts on which his work
is founded. It appears, therefore, probable, that a cycle
which actually formed a basis for the computation of a greater
period, in which the year of Sirius, the vague year, and the
lunar motions, again returned to the same epoch, must have
been obtained by slow and long-continued experience, which
was, therefore, long prior to the date of the origin of the cycle
that terminated in A.D. 138. The happy superstition of the
priests, — which led them to avoid restoring the vague year to
that of Sirius, as soon as the difference was detected, but
allowed their festivals to circulate through the different sea-
sons,— enables us to proceed back to the first year of the
previous cycle, when the first day of the year again coincided
with the heliacal rising of that star. As the rising of Sirius
marked the beginning of the agricultural year, to which the
vague year was restored by a cycle, the first year of 365 days
counted in Egypt must have fallen on the first year of some
given Sothic period. It could not have fallen in 1322 B.C.,
for it was, at that time, used as a mode of computation ; nor
could it have fallen earlier than 2782 B.C., because prior to
that period the cycle would not have been 1460 years.
That the cycle ending A.D. 138 was the only one actually
used as a period in the formation of a calendar, we have
strong additional evidence in a passage of Clemens Alexan-
drinus. Speaking of the exodus of the Israelites, he places
Egyptian Chronology. 465
it, not in a given year of a former cycle, but in the 345th year
before the Sothic period ; precisely as we cite events of ancient
history, as happening a given number of years before the
Christian era. And, in conformity, the extract cited by Biot
from a manuscript of Theon of Alexandria, in the Royal
Library of Paris, takes, as the epoch of his calculations, the
reign of Menophres, in which the cycle was renewed, or the
year 1322 B.C.
Thus, then, I conceive, I am warranted in my conclusion,
that the heliacal rising of Sirius was actually observed in
Egypt in the year 2782 B.C. ; and that, on the other hand,
this was the first year of 365 days reckoned in that country.
To whom this mode of computation, so different from that
of other nations, is due, is a matter of curious inquiry. Strabo
informs us, in the sequel to the passage that we have already
cited, that the Egyptians attributed their knowledge of the year
to Mercury. In the first dynasty of Manetho, the second
personage is Attothes ; the Thoyth of the Egyptians, the Thoth
of the Alexandrians, the Hermes of the Greeks. This Mer-
cury, therefore, was the son of Menes, and the second king of
Egypt. Cicero enumerates five Mercuries *. ( The fourth
was the son of Nilus, whom the Egyptians consider it impiety
to name ; the fifth, whom the Phenicians worship, who is said
to have slain Argus, and was for that reason appointed to rule
over Egypt, and to have given the Egyptians laws and letters,
him the Egyptians call Thoyth ; and the first month of the
year is by them called by the same name.' We find no other
ascription of the introduction of the year to this celebrated
personage ; but the other benefits that he conferred on man-
kind are the subjects of frequent allusion. Sanconiatho directly
names him as the inventor of letters f ; the same is done by
Philo J. ' I have heard/ says Socrates, in Plato's Phsedo, ' at
Naucratis in Egypt, that there was an ancient god, to whom
the bird they call the Ibis was sacred ; the name of this god is
Theuth ; he first invented numbers and the art of reckoning,
geometry and astronomy, and the games of draughts and dice.'
* § Nat. Deor., lib. iii.
t Eusebii Prep. Evangel., lib. i. J Ibidem.
466 Professor Renwick on
And so in Diodorus Siculus*: — * He first distinguished the
articulate sounds of language, and gave a name to many
things before destitute of name ; he invented letters ; pre-
scribed sacrifices and the worship of the gods ; he first ob-
served the course of the stars, and the nature and harmony of
sounds.'
' Letters,' says Pliny f , c I think always existed among the
Assyrians ; but others, as Gellius, think they were discovered
among the Egyptians by Mercury ; others again among the
Syrians. Anticlides says that they were invented in Egypt by
a person of the name of Meno, fifteen years before the time of
Phoroneus, the most ancient king of Greece, and endeavours
to prove it from monuments.' In the last passage we find
attributed to Menes the father, what was due to the son.
This extract from Pliny derives considerable interest from
modern discoveries. He states the discrepancy of opinion, by
which it seems, on the one hand, that the Assyrians had always
possessed letters, while, on the other, they were ascribed to the
Egyptians as inventors. We now know that the writing of the
Nile and Euphrates, if, perhaps, equally ancient, were founded
upon totally distinct principles ; the former being composed of
the resemblance of physical objects, originally extremely nu-
merous ; the latter of but two arbitrary and simple symbols,
made to express varieties of sound by their position in respect
to the horizon. It has so happened that the former, happily
simplified, seems to have extended its influence throughout
the greater part of the world, while the latter, although ob-
viously preferable, has sunk into such entire oblivion, that
even to decypher it mocks the industry and patience of the
most learned. From the Egyptians, the Hebrews and Phe-
nicians obviously borrowed the principle on which their alpha-
bets were founded ; hence proceeded the Greek, the Roman,
and the alphabets of modern Europe. Hence also, on the
other hand, diverged the Arab, and all the characters of the
present civilized nations of Asia, except the Chinese. Thus,
then, if in days of ignorance and debasement, the elevation of
the creature to honours due only to the Creator could be pal-
* Diodori, lib, i. t Plinii lib, viiv
Egyptian Chronology. 467
liated by the magnitude of the benefits which he became the
instrument of conferring upon our species, that superstition
which raised Attothes to the rank of a deity appears to have
the greatest justification.
Who, then, may it be inquired, was the father of this illus-
trious personage, his predecessor on the throne of Egypt P
Syncellus, in his dynasties, confounds him with Misraim, the
son of Ham, by whose name Egypt was called. Others, again,
consider him identical with Ham himself. Neither of these
names, however, has any similarity to that of Menes. It
may, therefore, be proper to search, whether there be any
name in the genealogies of scripture, to which we can refer
that of Menes, or, as he is sometimes styled, Anamenes. This
last form is found in that of Anamim, among the children of
Misraim *. The identity, when the Greek termination is
removed from the one, and the form of the Hebrew plural
from the other, is complete. Menes, then, was the third in
descent from Noah, and bore the same relation to the common
progenitor with Nimrod, the son of Cush, the first who
assumed royal authority in Asia ; and, by our previous com-
putation, it appears that his reign must have closed about
2782 B.C.: we may even place his death later; for some of
the expressions in relation to the. inventor of letters, would ad-
mit that he was not actually reigning at -the time the discovery
was made.
It remains that it should be shewn that this date is consistent
with the chronology of scripture. In England, I am aware
that the chronology of Usher is now exclusively adopted , and
as this places the flood in the year 2348 B.C., all such remote
antiquity is excluded. It is not, however, so in other coun-
tries ; the French let another chronology run parallel with that
of Usher in their best tables, and both appear to be admitted
as of equal authority by the Catholic church, while, by the
Greek, the latter alone is accounted authentic. Thus, then,
the question is one that is so far open, that it may be examined
without incurring the suspicion of wishing to interfere with
matters of faith, or the received interpretation of scripture.
• Genesis x, 13.
468 Professor Ren wick on
These two methods of computation are founded, the one on
the Masorete Hebrew text, the other on the version of the
Septuagint. The ancient controversy on their respective
authorities, so far as date is concerned, is well known ; which-
ever of them has been altered to suit the opinion of its guar-
dians has been changed with such skill, as to throw out of
use all the usual methods of critical emendation, by the aid of
the context. From this, however, may be accepted the name
of Cainan, which is found twice in the Septuagint, and but
once in the Hebrew, and who, not being found after the flood,
in any version but that of the Septuagint, may be rejected
from the list.
To compare these two chronologies, the following list may
be made use of. The first name is placed opposite the number
of years his birth dates after the flood ; the remainder oppo-
site to the age of the father, at the time the person named
was born.
HEBREW. LXX.
Arphaxad . 2 . 2
Salah ... 35 ... 135
Heber ... 30 130
Peleg . 34 . . 134
Ren ... 30 130
Serug- 32 132
Nahor ... 30 130
Terah 29 79
Nahor, elder brother of
Abraham 70 . 70
292 942
The difference between these two computations is 650 years ;
and, if that of the Septuagint be received, the flood, which,
according to Usher, took place in 2358 B.C., is carried back
to 2998 B.C.
This text is to be preferred for several reasons. The first
of these is almost obvious from mere inspection. It consists
in the fact, that the ages of the parents at which the children
are born, fall off, according to the Hebrew, suddenly after the
flood, and again increase in the case of Terah and Nahor ;
while, in the Septuagint, although lessened from what they
were before the flood, they still keep up the semblance of that
Egyptian Chronology. 4C9
gradual change, that we have a right to infer took place, in.
the growth and longevity of the human species, under the new
circumstances in which they were placed.
The next reason is to be found in collateral evidence. Be-
sides the Hebrew Text and the Greek translation, a na-
tion, equally hostile to the Christian religion and Jewish
people, has existed from the date of the captivity to the pre-
sent time, and a small remnant still remains in their original
seats in Palestine. This is the Samaritan, who, receiving no
others of the sacred books but those that compose the Penta-
teuch, have, with scrupulous care, preserved ancient copies of
them. The dates and genealogies of this text are identical
with those of the Septuagint, if the postdiluvian Cainan be
withdrawn.
Josephus was himself a Jewish priest of the highest class,
and had access to the sacred writings in the very last year of
their preservation in the temple. His chronology may, there-
fore, be considered as founded upon his best recollection of
the numbers he had there seen. The sum of his numbers is
993, which exceeds the computation of the Samaritan and
Septuagint ; and therefore confirms their deviation from the
Hebrew. It has been recently attempted to amend his text,
by conjectural criticism, and make it correspond to the Sama-
ritan. This, however, is unnecessary, for the present argu-
ment ; it is sufficient to shew that he confirms the general
truth of the longer computation, even if not identical with it in
his numbers. A third reason might be found in the calling of
Abraham, which, according to the computation of Usher, must
have taken place during the life of Shem ; for he lived 502
years after the flood, and the death of Terah, according to the
Hebrew text, took place no more than 427 years after that
important event. Although we might not presume to scruti-
nize the acts of infinite wisdom, still it may be permitted to
state, that the necessity for a renewal of the promise could
hardly have occurred, while there was a living witness of that
made to Noah, upon the earth, and in the very family of him
with whom the new covenant was to be made.
Another text of the Septuagint carries the flood back one
hundred years further, or to 3098 B.C.
VOL. I. ' MAY, 1831. 2 I
470 Professor Renwick on
The former determination, of 2998 B.C., is, however, suffi-
cient for our purpose. The family of Noah was speedily dis-
united, in consequence of the filial irreverence of Ham, and
a curse was pronounced by the indignant parent on the end
of the latter. Hence it requires no effort of reason to believe
that Ham speedily sought the country that became his apanage.
This is perfectly consistent with scripture, for Egypt took its
name from Misraim, who was three generations prior to Peleg,
in whose days the confusion of tongues took place. In this
branch of the family, too, life was more speedily reduced to
the present standard than in that of Shem, as is evident, from
the astonishment with which the longevity of Jacob was re-
garded in Egypt.
If seventy years be allowed to a generation among the de-
scendants of Ham, the third, whom we have held to be Athothes,
would have been of the age of seventy-four in the year 2782,
B.C., or 216 years after the flood ; and of course competent to
the highest exertion of his mental energies. This rapid de-
crease in longevity in Egypt is evident, from the dynasties of
Manetho, the first king, having a reign of sixty-two years ;
the second Athothes, of fifty-seven ; while the third falls off to
thirty-one : this, if we allow one hundred to Misraim, or thirty
less than to his cotemporary, Arphaxad, will correspond with
seventy years to a generation, at a mean rate. Thus, then,
the origin of the Egyptian year, in 2782 B.C., is fully consistent
with the best supported text of scripture, and even agrees in a
most remarkable, and I believe hitherto unnoticed, manner
with its genealogies.
III. The third mode of determining the epoch of Egyptian
chronology, is derived from a passage of Biot, in relation to the
groupe of zodiacal stars, in which the sun is situated at the
time of the heliacal rising of Sirius. This it may be as well
to cite, particularly as it contains quotations that bear upon
other parts of my argument.
Speaking of the work in the Greek language, which bears
the name of Horus Apollo, he says *, * The low antiquity of this
* Recherches sur plusieurs points tie 1' Astronomic Egyptienne, Paris, 1823,
p, 203.
Egyptian Chronology. 471
composition may be inferred from a passage when the true
epoch of the author discovers itself.' ( The Egyptians,' says
he, * distinguish this phenomenon by the emblem of a lion ;
because, when the sun enters into the Lion, the swelling of the
Nile becomes very considerable ; and while it remains in this
constellation (& £/w), the inundation often attains two-thirds
of its total height.' Now, according to the testimony of all
voyagers, from Herodotus to our own days, the Nile begins to
swell below the last cataract, immediately after the summer
solstice. Forty or fifty days elapse before it attains the half
of its greatest height, and it does not reach its last limit of its
increase until about one hundred days after the solstice. Con-
sequently, at this first phase of the swelling of the Nile,
which the passage cited marks as being already considerable,
the solstice must already be past a considerable number of
days ; it would have been at a distance of thirty days, if, for
instance, this place be supposed to correspond to one-third of
the total height. Now, since, according to our author, the sun
ought to be, then, in the commencement of the Lion, if we
suppose he cites this emblem as a sign, that is to say, a twelfth
part of Zodiac, it would be necessary that the solstice, falling
thirty days earlier, should take place in a point of the ecliptic,
that is, 30° more to the west, this carries it to the beginning of
the sign Cancer : * and as this disposition, which places the
two equinoxes, and the two solstices at the commencement of
the signs, was not generally adopted until after Hipparchus, it
follows that the work which employs it as such, must have been
written after the time of this astronomer.'
*****
Having determined by this physical indication the low
antiquity of the work of Horus Apollo, we shall examine here-
after what he says of the relations of Syrius with the Egyptian
year ; but I prefer, first, to discuss a passage of the Scholiast
of Aratus, which seems much more proper to enlighten us on
the real nature of these relations. This scholiast, who is
believed to be Theon of Alexandria, expresses himself in the
following manner * : — ' The Etesian winds,' says he, * invade
• Arat. Phen, Schol. on verse 153, ed Lips. p. 45.
2 I 2
472 Professor Renwick on
' the sea, when the Sun is the sign of the Lion ; and among the
' Egyptians, the keys of the temples bear the figures of a lion,
' from which hang chains, to which a heart is attached. They
< have consecrated the whole of this constellation (aar§ov) to the
' Sun. For then the Nile spreads beyond its banks, and the
' heliacal rising of the Dogstar takes place towards the twelfth
' hour*. They place at this instant the commencement of the
* year ; and consider the Dogstar, as well as its rising, as con-
' secrated to Isis.'
' The word employed by the author (aurgov) seems to indicate
that he wishes to consider the Lion as a constellation, and not
as a sign ; but the heliacal rising of Sirius in Egypt, of which
he makes a circumstance co-existing with the presence of the
Sun in the Lion, finally confirms this sense, by showing that it
is of the constellation that he speaks. In fact, the author of
the Scholia lived towards the fourth century of the Christian
era, and he cites the rising of Sirius as present, and taking
place in his own time. Now, at this epoch, when Sirius rose
heliacally in Egypt, which happened about twenty-seven days
after the solstice, the Sun was no longer in Leo considered as
a sign, but he had the same longitude with the stars of the
head of the Lion. For, by an astronomical circumstance that
has not hitherto been remarked, but of which I shall presently
give the demonstration, from more than 3000 years before the
Christian era, until more than 1000 years after that era, the
Sun has always been in the same constellation, Leo, but in
very different parts, at the time of the year in which the helia-
cal rising of Sirius takes place in Egypt.' At an epoch prior
to thirty centuries before the Christian era, the Sun would
have been in the groupe of Virgo at the time of the rising of
Sirius ; and hence the use of the hieroglyphic, or rather ana-
glyph, explained by Horus Apollo, could not have arisen at
an earlier date, and the claims set up to a much more remote
antiquity fall to the ground.
Biot also cites the passage of Porphyry, that has already
been quoted ; and in which, if we conceive that he has, as is
probable, united the traditions of the ancient Egyptians with
* An hour before sun-rise.
Egyptian Chronology. 473
the improved astronomy of his own day, there is strong cor-
roboration of our views. The citation is therefore repeated.
6 The Egyptians do not commence their year, like the
Romans, with Aquarius, but with Cancer; for near Cancer
appears the star Sothis, which the Greeks call the Dogstar ;
and the rising of the Dogstar is with them the renewal of the
year, because this star rules over the epoch of the nativity of
the world.'
This indication becomes still more precise ; for, according
to the calculation of Biot, from 2800 B.C. to 1000 A.D. the Sun
has always been in the sign Cancer, at the period of the year at
which Sirius rose heliacally in Egypt. And this did not, at
the time Porphyry lived, take place when the Sun was in the
first point of Cancer. Hence, when the Alexandrian school
fixed the epoch of their year at the entrance of the Sun into
Cancer, they must have referred to a circumstance that did not
exist in their own day, but which had occurred 2800 years
before the Christian era. Here, then, we again find an astro-
nomical epoch, of a date closely coinciding with the two already
determined.
IV. The passage in Herodotus is very remarkable, and its
meaning has been much disputed. Some, from its appearing
to involve an apparent absurdity, have been for rejecting
it as a fable ; while others have sought in it a hidden meaning,
whence the date of the origin of the Egyptian monarchy may
be deduced. The information of Herodotus was derived from
the Egyptian priests, and he does not appear to have himself
credited their statements ; still, however, he is not content with
detailing their communications simply, but adds comments of
his own, which obscure the sense that the mystic expressions
of the priests were intended to convey. Thus, in the earlier
-part of the passage, he informs us, that from Menes, the first
mortal who reigned in Egypt, they counted three hundred and
forty-one generations, and during this long series of genera-
tions a similar number of kings and priests. On this he
founds a calculation that these reigns comprised the vast
period of 11,340 years. But the calculation is obviously his
own ; and if it be admitted that, before the conquest of the
shepherd kings, Egypt contained several kingdoms, as is most
474 Professor Renwick on
probable, the number 341 does not appear excessive for the
time that has been deduced from other considerations. He
then goes on to state — * During this time, then, they said the
Sun has four times risen out of his customary places ; that
both where he now sets he had there twice risen, and where he
rises he had there twice set ; that this had not produced any
change in Egypt ; that the productions of the earth and the
inundations of the Nile had been the same ; and that there
had neither been more disease, nor a more considerable mor-
tality.'
This change in the rising and setting of the Sun, without
producing any change in the seasons or inundations of the
Nile, is mysterious in appearance ; but a reference to the
nature of the Egyptian year will render it at once obvious.
All that is to be remarked previously is, that the two clauses
of the passage are in contradiction with each other, and that
we, therefore, again see the double expression of the recital
of the priests, and the comment of Herodotus. A change in
the place of rising is attended with a corresponding one in
that of setting, and, therefore, by the last clause, which is in
detail, there are but two changes instead of four. The first,
therefore, is, from its vagueness to be rejected in favour of
the circumstantial account in the latter. Let us, then, see
whether this last account of the change be consistent with
astronomic phenomena. On the first day of the first vague
year of the Cynic Cycle, marked by the heliacal rising of
Sirius, the Sun was in the constellation of Leo, which was
then his accustomed habitation, or r^os. At the end of 730
vague years, or at the beginning of the 731st of the cycle, the
Sun would be in opposition to the stars of the constellation
Leo, and would of course rise with that point of the celestial
sphere which, on the same day of the vague year, at the com-
mencement of the cycle, had set as he arose ; and would set at
that point of the celestial sphere which, at the former epoch,
had risen at his setting. The change, therefore, spoken of
by the Egyptian priests, would have occurred for the first time ;
at the end of 1460 Julian years, he would again be in the
constellation Leo at the time of the rising of Sirius ; but at the
end of 730 vague years more, he would be in the position in
Egyptian Chronology. 475
which he had been at the beginning of the 731st year of the
previous cycle, and the same change would now be effected a
second time. Within the space, then, of 2190 years the sun
will have twice arisen, on a given day of the vague Egyptian
year, where he had at first set, and twice set where he had
before risen. Herodotus informs us, that the period of these
changes was included between the reign of the first king,
and that of Sethos, priest of Vulcan. The latter was re-
warded by Sennacherib, the date of whose reign is well esta-
blished at about 700 years B. c. Thus the most remote date
that this passage will permit us to assign for the beginning of
the reign of Menes is 2890 years B. c. It is, in addition, to
be considered, that the year of 365 days was the invention of
his successor, Attothes, and that every day by which the year
fell short of that number of days will tend to reduce the
length of this period ; and hence the estimate deduced from the
passage of Herodotus is easily reconciled with that of 2782
B.C., which has been deduced by other methods, as the close
of the reign of Slenes.
Neither of these modes of computation may, when standing
by itself, be of any great value, but, when united, they struck
me as furnishing a most convincing evidence, if not of the
exact time of the origin of regal government in Egypt, at least
of an antiquity, that however high it may be when compared
with that of the nations whose authentic history has come
down to us, is yet fully within the chronology of the sacred
volume. Their close and remarkable coincidence was wholly
unexpected by me, when I first took up the investigation,
for it was hardly to be anticipated, that in the vague and
scattered notices that have descended to us, of the origin and
antiquity of that mysterious people, anything that would point
out an exact chronological epoch could have been gleaned.
I must say, that the results are still a matter of surprise even
to myself: I cannot, however, avoid entertaining the hope
that the singular coincidence thus obtained by four separate
and distinct methods is not a matter of pure accident, but has
really an important bearing upon the date of the settlement of
Egypt, and thus upon the connexion of sacred and profane
history, and the disputed chronology of those remote ages.
( 476 )
AN ACCOUNT OF A REMARKABLE INSTANCE OF
ANOMALOUS STRUCTURE IN THE TRUNK
OF AN EXOGENOUS TREE.
BY JOHN LINDLEY, ESQ., F.R.S., &c.
Professor of Botany in the University of London.
fPHE following case will, perhaps, be found to offer an inte-
resting proof of the manner in which the wood is formed
in the trunks of Dicotyledonous, or Exogenous Trees : —
In the year 1828, I was informed that a poplar-tree had been
felled in a small court belonging to Mr. Nicol, near the Palace
of St. James's, which exhibited the singular anomaly of one
tree growing within another ; at the same time, I received a
specimen of a portion of the trunk of this supposed monster,
which was sufficiently in accordance with this statement to
justify the report, and to induce me to make further inquiries
upon the subject. Upon proceeding to the place where the
tree had grown, I fortunately found that the lower part still
remained in the ground ; and that this, with the fragment which
had been sent me, and those which were still scattered about,
contained nearly all the evidence that could be wished for of
the structure of the tree before it was cut down. The principal
specimen consisted of a shoot about four feet long, and an inch
in diameter at the thickest part, having the distinct marks of
the removal of a number of lateral shoots by a pruning-knife —
the scars being as sharp and well defined as if the branches
had been recently dissevered. No trace of bark was visible
upon this specimen, except one small patch, half an inch in
diameter at the lower end. The shoot was inclosed within the
solid trunk of a poplar-tree, about thirty years old, of which it
occupied the centre, but with which it had no organic connexion
whatever, except at the two extremities, where it was conti-
nuous with the trunk itself. The wood within which it lay was
applied closely to its surface, having, in the course of its forma-
tion, followed accurately every projection or impression upon
the surface of the shoot ; so that a cross section of the trunk
would have exhibited no appearance whatever of this inclosed
shoot, except by a circular line half an high from the centre,
Exogenous Tree. 477
resembling one of those concentric zones characteristic of dico-
tyledonous trees.
The connexion of the lower extremity of this shoot with the
trunk was a little below the ground line ; the shoot itself was
between four and five feet long; and throughout the whole of
this space there was, as I have before stated, no organic con-
nexion whatever between the surface of the shoot, and that of
the wood which overlaid it.
The question which naturally arises out of the consideration
of this specimen is, in what manner the shoot could possibly
have been formed in the situation in which it was found. This
enquiry is so closely connected with the formation of wood itself,
that, before I attempt to offer any explanation of the specimen,
it is necessary to examine in review the most important theories
of the formation of wood in exogenous trees, which have, up
to this time, been advanced by different physiologists. These
may be divided into four classes : 1st, that the bark is pro-
duced by the wood ; 2dly, that wood is produced by the bark ;
3dly, that bark and wood reproduce themselves ; and, 4thly,
that neither the wood nor the bark produces the new matter
which is deposited upon them, but that the latter owes its origin
to the vegetation of the leaf-buds.
The first of these opinions has been attributed to the Rev.
Stephen Hales, in whose very curious and useful work, called
Vegetable Statics, such sentiments are said to be discoverable.
I suspect, however, that there must be some mistake in this, as
I have not succeeded in meeting with any passage in that work
which can be said to indicate that such was the theory of the
author. He says, indeed, vol. i., p. 334, that he ' agrees in
opinion with Borelli, who, in his book, De Motu Animalium,
part 2, ch. xiii., supposes the tender growing shoot to be dis-
tended like soft wax, by the expansion of the moisture of the
spongy pith.' But it is not, perhaps, very important to inquire
whether he did entertain the opinion ascribed to him, as, if he
did, it has never been adopted by any succeeding writer, and
appears to be totally unsupported by evidence.
The second opinion is that of Malpighi and Grew, the latter
of whom, in his Anatomy of Plants, 2d edit., book i., p. 114,
§ 11, expresses himself thus : ' Every year the bark of a tree is
478 Mr. Lindley on an
divided into two parts, and distributed two contrary ways : the
outer part falleth off towards the skin, and at length becomes
the skin itself: the inmost portion of the bark is annually dis-
tributed, and added to the wood.3 This opinion has met with
many supporters, and is, I believe, even at this day, not uni-
versally abandoned. Du Hamel, as is well known, and after
him Mirbel, instituted the following experiment, in order to
determine the truth of Grew's opinion. If, they reasoned, a
metal plate is introduced between the bark and the wood in the
early spring, before the growth of the new year has commenced,
it ought to be covered by wood after a certain period, provided
the opinion of Grew be well founded. A plate of silver was
introduced, with the result that was anticipated. When exa-
mined, after the lapse of two or three years, it was found im-
bedded in the wood. At the same time that this experiment
seemed to prove the accuracy of the opinion that wood was
deposited by the bark, it also served to disprove the theory that
the bark was produced by wood.
Satisfactory as the result of this experiment may appear to
have been, physiologists have long been aware that it was
liable to several objections ; and hence has arisen the third
hypothesis to which I have adverted, that the bark and the
wood each reproduces itself; the substance out of which the
annual addition is formed being supposed to be the viscid
secretion found betweeen the bark and the wood, and known by
the name of c cambium.'
This view is that which is taken by many physiologists of the
present day. But if we consider that the tissue of both the
wood and the bark consists not only of cellular matter lying in
all directions, but also of vessels and fibres running in lines
parallel with the axis of development, and turning from their
course, if any obstacle is opposed to them, just as a current of
water when interrupted by stones or other obstructions, it
seems difficult to reconcile such a state of organization with the
idea of an induration of a mucous homogeneous deposit.
The fourth mode of understanding the origin of wood and
bark — namely, that they are caused by the descent of matter
sent down by the leaf-buds, is generally attributed to Darwin,
but may be also traced to Hales, who justly enough observes
Exogenous Tree. 479
(i. 340), « that it is not easy to conceive how additional ringlets
of wood should be formed by a merely horizontal dilatation of
the vessels; but rather by the shooting of the longitudinal fibres
lengthways under the bark, as young fibrous shoots of roots do
in the solid earth.' Whatever claim these authors may have
to suggesting this idea, it is certain that it is chiefly known at
the present day, in consequence of the writings of M. du Petit
Thouars, and one or two others who have followed him. This
doctrine leads to a curious view of the nature of plants in gene-
ral ; a subject upon which this is no place to enter fully, but
of which a concise explanation is necessary, for the attainment
of the end I have in view in this communication.
A plant is to be understood as a mass of individuals, each
having its own peculiar system of life, growing together in a
definite manner, and having a common organization, but
nevertheless capable of vegetating independently, and not un-
frequently separating spontaneously from each other. These
individuals are buds, each of which is perfect in itself, and
exactly the same as all the others of the same plant. They
are combined by means of a fibro-cellular substance called
bark, which is to be understood as being composed of the cel-
lular integuments of as many individuals as the plant may have
developed buds. As the act of vegetation consists in the
development of a germinating body in two opposite directions,
the one upwards, as stem, the other downwards, as root, — every
bud, when it begins to grow, must be subject to this law, pro-
vided it is the independent being which it has been represented
to be. And, in fact, if a bud is separated from the system to
which it belongs, it does follow this law of development, as is
well known to gardeners, from their practice of propagating
plants by buds and eyes. Now, if buds, when in a state of
combination, undergo the same kind of development as when
isolated, as it is reasonable to suppose, it will be found that the
fibrous and vascular tissue of the wood and bark, which always
descends from the buds, is really their roots ; and that, conse-
quently, the concentric circles of the wood and bark of dicoty-
ledonous trees are congeries of roots formed by the annual
development of buds upon the surface of the plant. It is well
known that, whatever the origin of the wood and bark may be,
480 Mr. Lindley on an
their fibrous and vascular tissue is held together by a cellular
substance which lies among them, assuming the form of plates
radiating from the centre to the circumference, and called
medullary rays. But it is apparent, from what has been
already stated, that if the origin of the wood and bark is such
as du Petit Thouars and his followers suppose, such an organic
connexion between the outside and inside of a trunk is not in-
dispensable to the formation of wood.
Let us now consider which of the three last theories best
explains the structure of the specimen which is the subject of
this communication. The central pruned axis was no doubt
the original stem of the poplar, and was formed anterior to any
of the superj acent wood ; and the question is, how the latter
originated, without some organic connexion with the centre.
If we could suppose, with Grew or Malpighi, that bark pro-
duces wood, we might find an explanation of the phenomenon ;
but as this theory is open to such distinct disproval in other
cases as to have been universally abandoned, a reference to it
in this instance is inadmissible.
If we suppose that bark produces bark, and wood wood,
we still are obliged to understand the existence of a continuity
of tissue between the part producing and the part produced.
Say that the cambium is the common matter, out of which the
wood and bark are both formed ; this substance is an exuda-
tion of the inner surface of the bark or the outer of the wood,
and is incapable of distinct separation from either. So that if
we suppose that this central axis was alive at the period when
the wood was formed above it, it is difficult to understand in
what way that organic connexion, which must have existed at
the period of the new formation, was subsequently destroyed ;
and if we suppose the axis to have been dead at that time,
there would be nothing left out of which the new wood could
be formed. Hence, it seems impossible to avoid the conclusion,
that the presence of a central axis, having no organic con-
nexion whatever with the parts surrounding it, is incapable of
explanation upon this theory.
But if we take the opinion of du Petit Thouars as the basis
of an explanation of the structure of this specimen, none of
the difficulties connected with the other hypotheses will be met
Exogenous Tree. 481
with. It is easy to conceive that, in any tree, almost any ex-
tent of living wood may be formed upon dead wood, in conse-
quence of the action of buds, provided a proper medium exists
in which the new matter can be formed ; and that, while no
cohesion takes place between living and dead matter, the usual
cohesion may be renewed as soon as two deposits of living
matter come again into contact. In this view the specimen
now under consideration will, I think, be found at once a
beautiful illustration of the theory of the formation of wood
from buds, and an insuperable difficulty in the way of any
other theories with which we are acquainted.
The explanation that might be given of this specimen would
be as follows : — The poplar, when its principal shoot was four
years old, was pruned, the whole of its lateral branches being
removed. Between the period of being pruned and the next
annual formation of wood, the whole plant died, with the ex-
ception of the terminal buds, (perhaps the bark,) and the root,
with that part of the stem immediately above it. As soon as
the terminal buds were called into action by the usual influence
of a vernal atmosphere, they obeyed the ordinary laws of
development, sending their roots downwards, under the bark, in
the form of wood and liber. These roots did not perish, in con-
sequence of there having been a sufficient quantity of moisture
between the dead bark and wood to favour their descent ; and
the moment they came in contact with the living part of the
stem at the ground-line, they united with it exactly in the same
way as if no dead matter had intervened. Supposing the bark
to have been alive, this descent would have been facilitated.
A communication once established in this manner between
the upper and the lower living portions, the intermediate axis
would be speedily inclosed within wood of its own nature, with
which it could have no organic connexion, on account of its
own previous death, and consequent incapacity of secreting
the cambium or matter of cellular organization, by which
alone this connexion is maintained. The absence of bark
from the surface of the loose axis of this specimen was the
necessary consequence of the mode of growth which I have
supposed to take place ; by which the whole of the bark,
whether living or dead, must necessarily have been pushed
482
Mr. Lindley on an Exogenous Tree.
outwards. As to the little patch of bark which was found
upon a small portion of the specimen, it may be presumed
that at that point there had occurred a
cohesion between the liber and alburnum,
which the force of the fibres descending
from the buds was not sufficient to over-
come, and that, in consequence, such por-
tion of the bark became incased.
Whatever opinion may be entertained
of the foregoing explanation, it, I think,
at least seems impossible to reconcile the
structure of this specimen with the theory
that bark produces bark, and wood wood;
while, at the same time, it is entirely con-
formable to the opinion, that wood and
bark are both the result of the development
of the numerous systems of vegetation, of
which every plant consists.
The accompanying wood-cut represents
the specimen, much diminished, and may
serve to convey a more exact idea of the
subject to which the foregoing remarks
apply.
( 483 )
ON THE FIRST INVENTION OF TELESCOPES, &c.
By Dr. G. MOLL, of Utrecht.
(Concluded from page 332.)
TTAVING heard what was adduced on the side of Lipper-
shey, we must now turn to the witnesses of Zacharias
Tausz, or Taussen.
The first of these is the ambassador, Boreel himself, a man
alike respectable for his rank, character, and abilities. He
says, that in 1591, the year in which he (Boreel) was born, a
spectacle-maker lived near his father's house at Middelburg j
that this man's name was Hans, his wife's Maria, and that,
besides two daughters, he had a son called Zacharias ; that
Boreel knew this Zacharias intimately, they having been play-
mates. This Hans, i. e, John, with his son Zacharias, as Boreel
often heard, invented the first microscope, which was presented
to Prince Maurice, and they obtained some reward. A similar
microscope was afterwards offered by them to the Archduke
Albert of Austria. When Boreel was ambassador in Eng-
land in 1639, he saw that identical microscope there, in the
possession of Cornelius Drebbel, of Alkmar, a man of much
knowledge, and mathematician to King James, the Archduke
having presented the microscope to Drebbel. This microscope
of Zacharias ^Yas not, continues Boreel, as they are shown at
present, with a short tube ; but it was about eighteen inches
long, and two inches in diameter, with a tube of gilt copper,
resting on two sculptured dolphins ; under it was a disc of
ebony, on which the objects to be examined were placed *.
But long after, in 1610, by dint of research, they (i. e. Hans
and Zacharias) invented in Middelburg the long sidereal tele-
scopes, with which we gaze at the moon, the planets, stars,
and heavenly bodies, of which a specimen was given to Prince
Maurice, who kept it secret, judging it useful in expeditions.
However, as this admirable invention was rumoured about,
and as curious men were talking about it in Holland and
* A stage.
484 Dr. Moll on the Invention of Telescopes.
elsewhere, a stranger came from Holland to Middelburg to
inquire into this matter, and, asking for a spectacle-maker, he
was shown by mistake into the shop of John Laprey. He spoke
with him about the secret of the telescope. Laprey, being an
ingenious man and a close observer, heard attentively what the
stranger said, and thus, with laudable industry -and care, be-
came the second inventor of the long telescope, which he
made to the satisfaction of the stranger. Therefore Laprey,
who by his ingenuity discovered a thing which was not shown
to him, deserves to be ranked as second inventor. He first
sold telescopes, and made them generally known. Afterwards,
Adrian Metius, Professor of Francker, and, later, Cornelius
Drebbel, came to Middelburg in 1620, and bought each a
telescope, not from Laprey, but from Zacharias Tausz.
From this evidence we may infer, that Hans, or John, and
his son Zacharias, were actually the inventors of a compound
microscope for opaque objects : the elegant ornaments of this
instrument, and the general description which Boreel gives of
it, make it probable that both Hans and Zacharias were men of
ability. But with microscopes we have at present nothing to do.
The point at issue is, whether either Hans or Zacharias, or any
body else, actually made telescopes before the 2d of October,
1608 ; and since Boreel indicates 1610 as the epoch of the
invention of Hans and Zacharias, the claim of Lippershey to
priority remains unshaken, even by the evidence of Boreel.
The following witness is John, the son of Zacharias, and
consequently grandson of this Hans, of whom Boreel has
spoken. He says, in 1655, that he then was fifty-two years
old ; thus, at the period when Lippershey sent in his petition, i. e.
in 1608, he was only five years old. He does not mention his
grandfather, but says, that his father, Zacharias, was the first
inventor of the telescopes ; and that this happened, as he had
often heard, in this town, in 1590; but the longest telescope
made at that time did not exceed in length fifteen or sixteen
inches. He affirms, that two such telescopes were then offered,
one to Prince Maurice, the other to the Archduke Albert ; and
that telescopes of such length were in use till 1618. At that
time, he, John, and his father, Zacharias, invented the con-
struction and fabric of the longer telescopes, which are still
•Dr. Moll O7i the Invention of Telescopes. 485
now used at night to look at the moon and stars. He further
says that, in 1620, a man of the name of Metius came to
Middelburg, and procured such a telescope, the construction
of which he afterwards tried to imitate ; and he adds, that
Drebbel did the same.
This witness, fixing the epoch of the invention at 1590, speaks
only from hearsay. Besides, he is in contradiction with Boreel,
who states that the invention of the telescope by Hans and
Zacharias was in 1610, at which time Boreel was nineteen,
and this John Zacharias only seven years of age. John
says nothing of the microscope, which Boreel actually saw and
described. It is certainly possible that one of the Metii, per-
haps the Professor, came to Middelburg in 1620, and bought a
telescope. But this does not decide the question of priority, as
we know, from incontrovertible authority, that Jacob Metius
was in possession of the invention in 1608. What happened
in 1620, when so many splendid discoveries were made by
means of the telescope, is not of the least consequence, as far
as concerns the first invention of the instrument.
There still remains another witness, whose evidence is very
immaterial and of little importance. It is a woman called
Sarah Goedard ; she is a sister of Zacharias Jansz : she
merely says, that it is forty-two or forty-four years ago since
her brother invented the long telescopes in Middelburg. She
often saw her brother at work making telescopes ; but she can-
not speak positively as to time.
This woman's evidence, who brings the invention to 1611 or
1613, cannot be of the slightest use in settling the question
between Zacharias and Lippershey.
It was then the soldier of Sedan, who first brought the in-
strument to France ; but his endeavours met with no great
success in that country. It is most astonishing to find the
French philosopher Peirese doubting the truth of the invention
of telescopes as late as 1622, and ascribing it to Drebbel, a
person wholly unconnected with it. In a letter to William
Camden, he says, * I should like to know what is true about
the inventions of Cornelius Drubelsius Alkmariensis, who, as is
said, has invented in your parts a globe representing ebb and
flood, a covered boat going between two waters, and long
VOL. I.- MAY, 1831. 2 K
486 Dr. Moll on the Invention of Telescopes.
spy-glasses (lunettes), with which a ivriting may be read at the
distance of a league, which we do not easily believe here*.'
And in another place I he says, ' We are told marvellous
things here about the inventions of Cornelius Drubelsius Alk-
mariensis, who is in the service of the King of Great Britain,
and who lives in a house near London ; amongst others, a
covered boat, which goes between two waters ; a glass globe,
which he makes to represent the tides, by a perpetual motion,
regulated like the natural tide of the sea, and of a spy-glass,
which makes one read a writing at more than a league (or a
mile) distance. I beg you to write me a word about the truth
of each of these inventions. We have here those small glasses
(lunettes), by which insects and mites appear as large as flies,
which is certainly admirable ; but I should like to know what is
true respecting these other inventions.'
It would appear that the invention was attributed by some
persons to the soldier of Sedan, whose name appears to have
been CrepiJ. He left, as we have seen, the Low Countries
in December, 1608, and in May following, 1609, we find a
Frenchman in Milan making telescopes. Sirturus § gives us
the following account of this transaction : —
* A Frenchman hurried to Milan in May, 1609, who offered
a telescope to the Count de Fuentes. He called himself a
partner of the Dutch inventor. The Count gave the instru-
ment to a silversmith, to have it included in a silver tube ; it
fell into the hands of Sirturus, who handled and examined it,
and made a similar one (if his assertion is to be believed) ; but
perceiving that much depended on the glass, he went to Venice
to get some at the workmen.'
Simon Marius, who disputed the discovery of the satellites
of Jupiter with Galileo, speaks of another Dutch telescope,
which came into foreign parts at a very early stage of the inven-
tion. He says that, in 1608, at the autumnal Franckfort mass
or fair (usually held in September), a certain General Fuchs
de Bimbach, an amateur of mathematics, heard from a Dutch-
* Gul. Caradenii et ill. viror. ad Camden. Epistol. London, 1691. p. 333.
t Page 387.
J Borel de verotelescopii inventore, p. 19.
§ Sirturus de telescopio. Edit, Franckf. 1618, 4to. minori, p. 25.
Dr. Moll on the Invention of Telescopes. 487
man then at the fair, that an instrument had been invented
which magnified objects and made them appear near. He
wanted to procure one of these glasses, but the Dutchman
asked too high a price ; but being returned to Onoldsbach,
Fuchs told the circumstance to Marius, adding that the instru-
ment had two glasses, one convex and one concave, of which
he even drew the figures. Marius adjusted glasses of thii
form, and convinced himself, to a certain point, of the possi-
bility of the thing ; but his object glass was too convex. He
ordered some other glasses of the opticians of Nurenberg ; but
he could procure none that suited his purpose. The next sum-
mer, of 1609, Fuchs got a tolerable instrument from Holland,
which he used with Marius in examining the heavens. About
the beginning of 1610, Fuchs got two well-polished glasses
from Venice, where they had been worked by T. B. Lanccius,
recently returned from Holland.
If the account of Marius deserves credit, the person who
brought the telescope to the Franckfort mass or fair, in Sep-
tember, 1608, did so a short time before Lippershey presented
his petition to the States, which was done the 2d of October of
that year. Fuchs, certainly with great reason, thought the
Dutch telescopes high priced ; we have seen Lippershey ask-
ing a thousand florins for one.
We are indebted to the English author of the Life of Galileo
for an instance of another Dutch telescope being brought to
Italy. Lorenzo Pignoria writes to Paolo Gualdo, from Padrea,
the 31st of August, 1609, * We have no news, except the
return of his Serene Highness, and the re-election of the lec-
turers, among whom Signor Galileo has contrived to get 1000
florins for life, and it is said to be on account of an eye-glass,
like the one which was sent from Flanders to the Cardinal
Borghese. We have seen some here, and they succeed well.'
It will, after all, be very difficult to deny, that not only the
rumour of the invention, but even some telescopes actually
made, reached Italy from Holland, before Galileo ever made
such an instrument. In May, 1609, there was a telescope in
the hands of the Count de Fuentes. Another was in the pos-
session of Cardinal Borghese; Lanccius, who came from
Holland, is said to have made telescopic glasses at Venice ;
2 K 2
488 Dr. Moll on the Invention of Telescopes.
Fuccarins distinctly says, that one Dutch telescope was brought
to Venice, and that Galileo saw it*. But such is our respect
both for the genius and the character of Galileo, that his mere
assertion that he never saw a telescope when he set about
making one ; that he did £not know its construction, that his
friend Jacob Badorere, by whom he got intelligence of the
invention from France, did not give him any information of
the manner in which it was made — his simple assertion of all
this is taken by us as conclusive against any presumption.
Nelli, in his Life of Galileo, says, that the Florentine phi-
losopher first heard of the invention in June, 1809. Galileo
himself informs us, in a letter written in March, 1610, that he
heard of the invention about ten months ago, which would fix
the time of his first attempt to the month of May, 1609, the
time when, we know from Sirturus, that a Frenchman brought
the telescope to Milan.
Even after the very able manner in which the history of
Galileo's discoveries have been recently given by an English
author, it will not be superfluous to give Galileo's own account
of the transaction.
In March, 1610 f, he wrote in the following manner: — ' It
is about ten months ago that it came to our ears, that a glass J
had been worked by a Belgian, by the help of which, visible
objects, though at a great distance from the eye of the ob-
server, may be seen distinctly. (In the Italian of the Sag-
giatore it is added, ne piu aggiunto, no more was added, or
this was all.) And some experiments were related of the
admirable effects of this instrument, which some believed,
and others not. A few days afterwards the same was con-
firmed by letters of a noble Frenchman, Jacob de Badorere,
from Paris ; all which occasioned me to apply myself wholly
to inquire into the cause of this, and to think on the means by
which the invention of a similar instrument might be brought
about ; in which I succeeded in a short time, assisted by the
doctrine of refraction : and I first procured a leaden tube, at
the end of which I adapted spectacle glasses §, both plane on
one side, the one convex on the other side, the second con-
* Kepleri epistolae, No. 309, p. 493. f Epist. 4. Td. Martii, 1610.
J Un occhiale, perspicillum. § Vitrea perspicilla.
Dr. Moll on the Invention of Telescopes. 489
cave. Bringing the eye near the concave glass, I saw the
objects large, and near enough : they appeared three-times
nearer, and nine times larger, than if seen with the naked eye.
' Afterwards I made another instrument, which made objects
appear sixty times larger.
' Finally, sparing neither industry nor expense, I succeeded
so far as to make an instrument of such excellence, as to
make the objects seen through it, appear a thousand times
larger, and more than thirty times nearer, than if seen with the
natural power of the eye.'
Viviani, Galileo's favourite pupil and friend,*, says, that in
the month of April or May, 1609, it was rumoured in Venice,
where Galileo then was, that a Dutchman presented to Count
Maurus, of Nassau, a certain glass occhiale, with which distant
objects appeared as if they were nearer, nothing more was
said-\. With this information only Galileo returned imme-
diately to Padua, to try whether he could find out the con-
struction of this instrument, in which he succeeded on the
following night. The next day was employed in construct-
ing the instrument, in the manner which he had imagined ;
and, notwithstanding the imperfection of the glasses which
he procured, he saw the effects which he anticipated, and
immediately gave notice of it to his friends in Venice. He
constructed, after this, instruments of better quality ; and
six days later he took some of them to some elevated part
of the city, and made the first senators of the republic observe
distant objects, which they did with great admiration. Bring-
ing constantly the instrument to greater perfection, he re-
solved finally, with his wonted liberality, to communicate his
invention, and to make a free gift of it to the serene Prince
and Doge Leonardo Donati, and to the Senate of Venice,
presenting with the instrument a paper, in which he declares
the construction, and the admirable use and results on land
and on sea, which might be obtained from this invention.
In consequence of this noble present, the serene republic,
with generous demonstration of the 25th of August, 1609,
wrote to Galileo, and a pension was granted him for life, with
* Viviani vita del Galileo, p. 69. t A* pi» oltrifu detio.
490 Dr. Moll on the Invention of Telescopes.
more than three times the salary, which it was the custom to
give to a lecturer of mathematics.
Thus we perceive the Venetian Senators doing in August,
1609, the same thing which the members of the slates-general
had done in October, 1608, about ten months sooner. They
ascended to high places for the purpose of gazing at distant
objects. Both the Dutch and the Venetian magistrates nobly
rewarded the invention, which was tendered to them. The
Venetians rewarded Galileo as a philosopher should be re-
warded, by an honourable station and independence. The
Dutch treated Lippershey in the best way an artist can be
treated ; they gave a high price for his article, and made large
orders for it. The date assigned by Viviani to these trans-
actions, the 25th of August, 1609, agrees completely with
what Lorenzo Pignoria wrote the 31st of August to Paolo
Gualdo, and which letter was mentioned above.
It is exceedingly gratifying to observe, that Galileo almost
immediately brought the telescope with a convex object-glass
and a concave eye-glass, to all the perfection of which it is sus-
ceptible, without being achromatic. He observed with it all
that could be seen by its means ; he ascertained the power of
his glasses with great ingenuity, and he indicates the difference
between linear and superficial amplification with perfect ac-
curacy. His German biographer, Tagemann, does not seem
to have clearly understood this difference, for he appears to
imagine that Galileo's telescope really had a power of a
1000 times, whereas it was only of about 32.
In a Galilean telescope the focal length of the object-glass
cannot go beyond a certain extent, without narrowing the
field too much. The eye-glass cannot be made very deep
without making it too thin in the centre. Even at present, it
would, perhaps, be difficult to make Galilean telescopes of
greater power than 32, which is, indeed, that which Galileo
obtained.
On the 7th of January, 1610, Galileo discovered three of the
satellites of Jupiter ; on the 13th, the four satellites were ob-
served and recognized as satellites ; but it is not my object to
enter into that splendid strain of discoveries which illustrated the
name of Galileo, and which lately have been so well described.
Dr. Moll on the Invention of Telescopes. 491
However perfect we allow the instruments of Galileo to have
been, we see no reason to doubt that the satellites could
be seen with the instruments made in Holland. The Italian
authors certainly assure us that the Dutch telescopes were of
an inferior description ; but this assertion is wholly unsupported
by proof. Indeed, we know nothing of these telescopes, except
that they were long (tubi lonyi), and longer than sixteen
inches * ; and it is not unrational to suppose that, with this
length, they were equal to Galileo's telescopes. Admitting the
length of the telescope to have been sixteen inches, and the
negative focus of the concave eye-glass half an inch, the
power of the telescope was 32, or equal to that of Galileo.
The Professor Adrian Metiusf, brother of the co-inventor of
the telescope, gives us some account of what could be seen
with the telescopes then made in Holland. In a book printed
in 1614, he says, ' During the day several planets are observed
near the sun, which were unknown hitherto to all men, but
which can only be seen with the glasses, which my brother,
Jacob Adriaansz, invented six years ago (thus in 1608).
These planets show themselves first in the eastern part of the
sun, and from thence pass over the sun to the westward, in
about ten days, as I observed several times, principally about
sunrise and sunset.
' With these same tubes some erratic stars or planets are
seen, which have their course round Jupiter ; but of these
nothing can be stated with certainty, unless my brother be
pleased to publish his telescopes, by means of which many
strange things will be brought to light, as well about the moon
as elsewhere. Yea, the observations of the stars may then be
made with much greater accuracy ; because, by means of
these telescopes, it will not only be possible to observe minutes,
but even seconds.'
It does not appear from this quotation that the professor
himself observed the satellites ; nor does he even appear to be
aware of their number. His brother Jacob, perhaps, gave him
some incomplete information of the existence of the satellites.
* De vero telescopii inventore, p. 30.
t Adriani Metii, Institut. Astronom. et Geograph, Francq. 1614. Fonda-
mentale en groudelyche ouderuy singe, ibid 1614. Adriani Metii tract at us de
genuine usu utrusque globi, Francq. 1624. 4to.
492 Dr. Moll on the Invention of Telescopes.
But Ae saw the spots of the sun, which may be seen Avith in-
struments of a less power; and he labours under the erroneous
notion, then common to many, that the spots were planets or
satellites circulating round the sun.
But what the Professor says of the accuracy which the inven-
tion of the telescope is likely to insure to astronomical observa-
tions, is very remarkable. What does he mean by assert-
ing, that the observations on the stars will become accurate to
a second ? Did the pupil of Tycho anticipate the application
of the telescope to instruments of mensuration ; to quadrants ?
I must own that it is difficult to take his distinct words in any
other sense ; and I am led to believe, that the idea of an inven-
tion, which did so much credit to Gascoigne, had occurred
to Adrian Metius.
There is a passage in the English life of Galileo, which
ought not to pass unnoticed. The anonymous author accuses
William Boreel, to whom he chooses to give the Italian name
of Borelli, of glaring partiality against Galileo. ' Borelli,'
says this author, not ' satisfied with attributing the invention of
telescopes to Zanssen, endeavours to secure for him and for
his son the more solid reputation of having anticipated Galileo
in the useful employment of the invention. He has, however,
inserted in his collection a letter from John, the son of Za-
charias, in which John, omitting all mention of his father,
speaks of his own observations of the satellites of Jupiter, evi-
dently seeking to insinuate that they were earlier than Galileo's ;
and in this sense the latter has been since quoted, although it
appears from John's own deposition, preserved in the same
collection, that, at the time of the discovery, he could be no
older than six years. An oversight of this sort throws doubt
on the whole of the pretended observations ; and, indeed, the
letter has much the air of being the production of a person im-
perfectly informed on the subject on which he writes, and pro-
bably was compiled to suit Borelli's purposes, which were to
make Galileo's share in the invention appear as small as
possible.'
I crave the liberty of replying to this passage, that if proba-
bilities are to be introduced in the case, it seems extremely
probable that the learned author of the Life of Galileo has
Dr. Moll on the Invention of Telescopes. 493
never read Borel's book with sufficient attention, and, as the
book is scarce, he knows it perhaps only from quotations.
There is no letter inserted in it from John, the son of Zacha-
rias ; but in answer to some queries either from Boreel or
from Borel, he gives two memorials or notes of what a tele-
scope of his making could show. In the first place, he men-
tions the appearances and dark places in the moon ; and it is
to be observed, that what he says of the appearance of the
moon seen through his telescope, answers exactly to what one
would expect of a good instrument. It plainly shows, says
John, the moon to be a sphere, with distinct edges, and not a
plane. The following is his statement of Jupiter's satellites :
he often observed the planet which shows itself round, well
defined, and spheric ; near it he often saw two highly situated
small stars, sometimes he saw three, and generally four of
these small stars. As far as he could observe, they go perpe-
tually in circles round Jupiter ; but he adds, this I leave to
astronomers to determine, for it is not, says he, my business to
make astronomical observations, but to furnish astronomers
with telescopes as good as I am able to make.
I challenge the author of the life of Galileo to point out the
passage in Borel's book in which either Boreel, or John, the
optician, exhibit the least intention of throwing Galileo's disco-
veries in the shade. But it may be permitted, I should think, to
an optician, when asked by an ambassador at a foreign court, to
state what the performance of his instruments is ; and I believe
that neither Mr. Dollond nor Mr.Tully could be justly accused
of disparaging Sir William Herschel's merit, if they were to
state that the Georgium Sidus is visible in their telescopes.
John certainly says, in 1655, when he was fifty-two years of
age, that he often saw four satellites with a telecope of his own
making ; but he never says that he saw the satellites before
January 1610, the epoch of Galileo's discovery, nor does he
even mention when he first saw them. He is, says he, no
astronomer, but an optician ; and when this optician states, in
1655, that he makes telescopes with which the satellites can be
seen, it is difficult to understand how it can be inferred that he
made this statement in order to deprive Galileo of the honour
494 Dr. Moll on the Invention of Telescopes.
of discovering the satellites in 1610. Thousands, certainly
hundreds, saw the satellites in 1655 ; and why should not
John, like other people ? I, therefore, positively deny that
any intention is shown in Borel's book, to depreciate the
merits of Galileo ; and, as far as Boreel is concerned, con-
sidering his character and station in life, it is absurd to say,
that his evident object was to make Galileo's share in the
invention as small as possible ; but if Boreel really under-
valued Galileo's merits, let the English author quote, and
point out the place where he did so. I must offer another
remark to this same anonymous author, I am quite prepared
to believe that the telescopes made by Galileo's own hands
were as perfect as art could make them at the time; but
it is to be lamented, if the original telescope of Galileo still
exists in Florence, that no Italian philosopher has favoured us
with an account of its performance. We have, however, a sort
of criterion of what could be done by it. The belts of Jupiter
were, as far as I know, never seen by Galileo ; they were
observed, after his death or blindness, with instruments made
by Evangelista Torricelli. But the author of the English
life of Galileo asserts, as proof of the inferiority of the Dutch
telescopes, that, in 1637, ' Gaertner, or, as he chose to call
himself Hortensius, wrote to Galileo, that no telescope could
be procured in Holland, sufficiently good to show Jupiter's
disk, well defined*.' Hortensius wanted more than could be
accomplished in his time ; and even now, telescopes of a cer-
tain size, which show Jupiter's disk well defined, are not of every
day's occurrence. Does this author know many telescopes
excepting those made by Mr. Dollond or by Mr. Tully, capable
of showing Jupiter's disk, well defined; nay, does he know one
single telescope, not achromatic, capable of answering the
claim of Hortensius. The anonymous author favours his reader
with a translation of Hortensius's name, which he pronounces
to be Gaertner. He is mistaken, however: Gaertner certainly
is the German of Hortensius ; but he was not a German,
and his name, in his mother tongue, was Van den Hore.
We find the celebrated Peirese, as late as 1622, doubting
* P. 25.
Dr. Moll on the Invention of Telescopes. 495
the invention of telescopes : in England, these instruments
were known at a much earlier period. The celebrated English
mathematician, Thomas Harriot *, actually observed the satel-
lites of Jupiter, as early as the 10th of January, 1610, which is
only eleven days later than Galileo's discovery. It is, indeed,
astonishing that an English author should overlook this circum-
stance. Harriot also observed the spots in the sun for the first
time on the 8th of December, 1610. They were first seen by
Galileo in November of the same year. Harriot's telescopes
had, it appears, powers of 10, 20, and 30. His observations
run from the 16th of January, 1610, to 26th of February,
1612 ; he gives drawings of the configurations and computation
of their revolutions. Now, it may be asked, from whence did
Harriot get the telescope with which he observed the satellites
only a few days later than Galileo ? Certainly not from Italy ;
he either made it himself, or got it from Holland.
But a few months later we find another English astronomer
furnished with a telescope. Sir Christopher Heydon writes,
on the 6th of July, 1610, to the well-known William Camden :
— ' I have read Galileo, and, to be short, do concur with him
in opinion ; for his reasons are demonstrative ; and of my own
experience, with one of your ordinary trunks, I have told eleven
stars in the Pleiads ; whereas no age ever remembers above
seven; and one of these, as Virgil testifieth, not always to
be seen y.'
Telescopes were then, it appears, called trunks. Harriot,
in his letters to Henry Percy, Earl of Northumberland, calls
them perspective cylinders. It appears that the earl possessed
many of them, and that he wanted some more. It is to be
lamented that Harriot's papers and manuscripts are at present
buried, in one of the libraries of the University of Oxford.
From all which has been said in this paper, the following
facts may be established, as proved by authentic documents : —
* These observations, and other manuscripts of Harriot, were discovered, in 1784,
by Baron de Zach, at Petworth, in Surrey, the seat of Lord Egremont. See
Bode's Astronom. Tahrbuch. 1788, p. 155, Monatliche Correspondenz, t. viii.
p. 144.
t Gulielrai Camdeni et iilust. viror. ad G. Camden. Epistol. Loadou 1691,
p. 128.
496 Mr. Rennie on the Contrivances
That on the 2d of October, 1608, John, or Hans Lipper-
shey, a native of Wezel, a spectacle-maker of Middelburg, in
Zeeland, was actually in the possession of the invention of
telescopes.
That, on the 17th of October, of the same year 1608, Jacob
Adriaansz, sometimes called Metius of Alkmar, in Holland, also
was in possession of the art of making telescopes, and that he
actually made those instruments ; but that either from disgust
or some other reason he afterwards concealed his invention, and
thus actually gave up every claim attached to the honour of it.
That there is little reason to believe that either Hans, or his
son Zacharias Zansz, were also inventors of the telescope ; but
there is every probability that this Hans, or John, or his son
Zacharias Zansz, invented a compound microscope about
1590.
That this Lippershey used rock or mountain crystal in the
construction of telescopes, and that he is the inventor of the
Cinoculus.
ON THE CONTRIVANCES OF SOME ANIMALS TO SECURE
WARMTH.
BY J. RENNIE, A.M., A.L.S.
Professor of Natural History, King's College, London.
HPHOSE who adopt the opinion, that the lower animals are
actuated in their movements by reason, rather than by
what is termed blind instinct, may find abundance of facts
illustrative of their doctrine in the various modes employed by
animals to keep themselves warm. But without involving our-
selves deeply in the curious metaphysical controversy respect-
ing instinct and reason, which seems to have little chance of
being speedily decided, it may not be unprofitable to bring a
few of the facts just alluded to under review. Some of these
facts may be daily observed by anybody who will take the
of Animals to secure Warmth. 497
trouble, though they seldom draw attention, or excite inquiry,
and yet they may frequently give origin to the most interesting
researches in natural history.
Without going further than the hearth-rug beside my chair,
I may begin with the cat, which prefers that hearth-rug to any
other corner of my study ; and though she cannot be said to
exhibit much contrivance in keeping herself warm, compared,
at least, with her insidious cunning in taking her prey, she
certainly shows most surprising knowledge and tact in disco-
vering the best non-conductors of heat. Darwin would have
considered this as unequivocal proof of knowledge derived from
experience * ; but as I cannot bring myself to give cats the
credit of discovering, and then acting ! upon the philosophic
principles of the distribution of caloric, I shall venture upon
the inference from the fact, that they are not indigenous (con-
trary to the received opinions) to so cold a climate as Britain,
and are impelled to search after warm places, in consequence
of their great impatience of cold.
The feet of the cat, though they are thickly clothed with
hair above, and padded with a soft cushion of thickened epi-
dermis, intermediate between cartilage and tendon, on the
soles, may be always observed to be cold to the touch when
the animal has been exposed to a low temperature, as are the
ears likewise ; and, in such circumstances, it manifests its
uncomfortable feelings by restlessly wandering about till it can
find a warm corner. This very appetite (if it may be so called)
for warmth, appears to me to be the chief cause which pre-
vents our domestic cats from ever becoming wild; for, in
every part of the country where there are woods, they might
find abundant prey ; and it is well known, that when cats once
take to bird-catching in the woods, they never afterwards eat
anything dead but with reluctance. I have had many oppor-
tunities of observing cats in this half wild state; but though
they depended for food wholly upon what birds and mice they
could catch, and were so wild as scarcely to permit themselves
to be seen, much less approached, yet no instance ever came
* Zoonomia, i. 8, 16, and Brown's Observ. p. 263.
498 Mr. Rennie on the Contrivances
to my knowledge of their having made their domicile in the
woods, but uniformly sleeping and littering in the least fre-
quented barns and other out-houses of farms. This I am in*
clined to attribute wholly to their finding such places warmer
than any they could discover in the woods, and to the supply
of mice they might find there when birds were less plentiful ;
for it could not well be traced to their attachment to man,
whom they always fled from as fearfully as a fox would do.
A more particular instance of this once came under my
observation. A cat, which had been long remarked as one
of the wildest of those which frequented a barn on the borders
of a wood in Ayrshire — so wild, indeed, as to be seldom seen
— was, several times during a sharp frost, observed, with no
little surprise, to pass and repass into the adjacent farm-house,
which it had not for some years been known either to enter or
approach. It might have been inferred that it was compelled
by hunger, had not this been the best season for catching
birds; but, in one of its stealthy visits, it was seen snugly
coiled up beside a baby in the cradle, to the no small horror
of the mother, who imagined, in accordance with the popular
prejudice, that it had come to suck away the baby's breath.
All I could say to persuade her of the impossibility of the cat
doing this was of no avail, and orders were immediately given
to every servant on the farm to kill the poor cat wherever she
could be found. Her caution and agility, however, were long
successful in saving her ; and though the persecution she
thus experienced rendered her, if possible, much wilder than
before, yet she was not thereby deterred, not even after being
wounded by a pitchfork, and her leg lamed by throwing a
hatchet at her, from paying a daily visit to the baby in the
cradle, because it was the warmest place within her knowledge ;
and, next to food, she considered warmth an indispensable of
life. She persisted thus in venturing to the cradle, till she
was at length intercepted and killed.
It is worth remarking, that this cat was a pale tabby, of
small size, with a long slender tail tapering to a point ; none
of which circumstances agree with the common wild cat (Felis
catus, LINN.) found in our mountain woods. The latter has
of Animals to secure Warmth. 499
a short tail, which, when bent over the back, Only reaches to
the shoulder, while it is thick, or rather broad, and does not
taper, but ends bluntly, as if a portion had been cut off.
M. Temminck, looking at these distinctions, and also at the
great difference of size — the wild being a third larger than the
domestic cat — is of opinion that they are decidedly different
species; and he is disposed to consider a new species (Felix
maniculata) recently sent from Nubia by M. Ruppel, as the
original of the domestic cat *, which opinion would accord
with the above remarks respecting its impatience of cold.
Linnaeus and Buffon seem to have been among the first to
confound these two species, though the latter was aware of
the remarkable difference in the length of their intestines ;
those in the wild cat being only thrice the length of the body,
proving it to be purely carnivorous, while those of the domestic
cat are much longer, being nine times the length of the body,
proving it to be able to subsist on a portion of vegetable food,
and, accordingly, we find that our cats are very fond of boiled
greens, &c., which it is probable no wild cat would touch.
That these changes are not caused by domestication, is proved
by no such difference appearing in the intestines of the wild
boar and the pig, and by domestic animals being always in-
creased rather than diminished in size when compared with
their known wild originals. To enter more minutely into this,
however, would lead me too far from my immediate subject ;
but it may be worth mentioning, that the domestic cat is only
of recent introduction in the higher northern latitudes, as in
Sweden f and Norway J, while they are not yet introduced
into Lapland §.
From the chinchilla (Chinchilla lanigera), being a native of
Chili, it was inferred that, like the cat, it might be pleased to
lie warm, and a piece of flannel was accordingly given to one
in the collection of the Zoological Society ; but, instead of
lying upon it as a cat would have done, it always pulled it
about, and dragged it to the outer division of its cage. It is
* Temminck, Mammalogie, No. iv. sp. 17.
t Linnaeus, Faxina Suecica. J Pontoppidan, Nat. Hist. Norw. ii. 18.
6 Zimmermann, Specilegia Zool. Geograph. p. 172.
500 Mr. Rennie on the Contrivances
to be recollected, however, that both its fur and skin are thick ;
while the skin of a cat is very thin and tender, which make it
both susceptible of cold, and, as Pennant observed, terribly
afraid of being beat.* The demoiselle heran (Anthropoides
Virgo, VIEILLOT), which Buffon had from the coast of Guinea,
was more attentive to its comfort than the little chinchilla;
for he tells us, ' it had chosen for itself a room with a fire to
shelter it during the night, and in winter (1778) it repaired
every evening to the door, sounding for admission •)•.' This
indicates more intelligence, instinct, or whatever it may be
called, than occurs in an animal much wiser in appearance.
A similar anecdote is related by M. Antoine of a lapwing
( Vanellus cristat us, MEYER), which a clergyman kept in his
garden. It lived chiefly upon insects ; but as the winter drew
on these failed, and necessity compelled the poor bird to
approach the house, from which it had previously remained at
a wary distance ; and a servant, hearing its feeble cry, as if it
were asking chanty, opened for it the door of the back kitchen.
It did not venture far at first, but it became daily more fami-
liar and emboldened as the cold increased, till, at length, it
actually entered the kitchen, though already occupied by a dog
and a cat. By degrees it at length came to so good an under-
standing with these animals, that it entered regularly at night
fall, and established itself at the chimney-corner, where it
remained snugly beside them for the night ; but as soon as the
warmth of spring returned, it preferred roosting in the garden,
though it resumed its place at the chimney-corner the ensuing
winter. Instead of being afraid of its two old acquaintances,
the dog and the cat, it now treated them as inferiors, and
arrogated to itself the place which it had previously obtained
by humble solicitation. This interesting pet was at last choked
by a bone which it had incautiously swallowedj.
The Barbary Ape (Macacus sylvanus, LACEPEDE), which,
though a native of Africa, has established a colony on the rock
of Gibraltar. Here it is occasionally so cold in winter, that
* British Zoology, vol. i. f Oiseaux, ART. L' Oiseau Royal.
I Antoine, Anlmaux Celebres, i. 70.
of Animals to secure Warmth^ 501
these poor apes are fain to huddle about any chance fire that
may be lighted out of doors and left burning ; but though they
are seen sitting close to the dying embers, they have never been
known to add a single chip of fuel to continue the fire * — a cir-
cumstance somewhat at variance, indeed, with the title of this
paper, but not the less curious, as illustrative, by contrast, of
animal manners.
Animals which lie torpid during winter are usually careful to
provide a warm and well sheltered domicile for their long sleep,
and it is not a little interesting to observe the proceedings
of different species. The edible snail (Helix pomatia, LINN.),
for example, found in the middle districts of England, but
supposed to have been introduced from the Continent in the
sixteenth century, forms, at the end of autumn, a very curious
winter cell. When at liberty, it constructs this cell of earth,
moss, and withered grass, by means of its muscular foot,
enlarging the cavity by turning itself round, and forming the
roof by carrying up portions of earth and mossf . But, accord-
ing to Mr. Bell, * it is not by the pressure of the foot and
the turning round of the shell that this is principally effected.
A large quantity of very viscid mucus is secreted on the under
surface of the foot, to which a layer of earth or dead leaves
adheres ; this is turned on one side, and a fresh secretion being
thrown out, the layer of earth mixed with mucus is left. The
animal then takes another layer of earth on the bottom of the
foot, turns it also to the part where he intends to form the
wall of his habitation, and leaves it in the same manner,
repeating the process until the cavity is sufficiently large, and
thus making the sides smooth, even, and compact. In form-
ing the dome or arch of the form, a similar method is used, the
foot collecting on its under surface a quantity of earth, and the
animal turning it upwards, leaves it by throwing out fresh
mucus, and this is repeated until a perfect roof is formed^.'
I brought a pair of these animals from the woods of Godes-
berg on the Rhine in 1829 ; and as they were kept under an
inverted glass, with only a few leaves, it was amusing to see
* Scott, Intell. Philosophy, iv. 1.
t M. Gaspard in Majendie's Journ. de Physiologic, ii. 295. '
J Zoological Journal, i. 94, note.
VOL. I. MAY,_1831. 2L
502 Mr. Rennie on the Contrivances
how solicitous they appeared to be to make the most of these
in forming their cells. One of them made the side of the glass
a part of the wall of its cell, against which it formed a sort of
arch with what leaves chanced to be within its reach ; but as it
seemed to have no idea of bringing materials from a distance,
the covering was thin and imperfect. The other attempted to
establish itself in the middle of the area, apart from the sides
of the glass ; but it was less successful than its fellow, as it
always deranged the portion of wall it had constructed by turn-
ing about in search of materials. It was curious to remark the
different habits of two other species of the family (Helix
aspersa, and H. nemoralis, M CILLER) confined under the same
glass : the latter giving themselves no trouble about a covering,
crept quietly up as high as they could get, and formed their
calcareous lid (operculum) upon the bare glass ; the second of
the edible snails was at length reluctantly compelled to follow
their example, after being foiled in all attempts to cover itself
with a dome of leaves.
Our common hedgehog (Erinaceus Europ&us) makes a
similar preparation to the preceding for his winter's sleep,
being frequently found so bewrapped in leaves as to have little
resemblance to an animal. The hedgehog, however, has not,
so far as I am aware, been ever observed in the act of forming
this covering of leaves, though it is supposed to roll itself about
till its spines take up a sufficient number, in the same way it is
popularly believed (without proof) to do with apples. That it
collects leaves for this purpose, and carries them to its den,
has been repeatedly witnessed ; and when domesticated, it will
construct a barricade of leaves at the mouth of its den*. It
would hence appear that the ancient Greeks erroneously
undervalued the skill of the hedgehog, when, comparing it with
the poly sophia of the fox, they said it only knew the important
art of defence f.
The hare, which remains active all winter, is somewhat less
provident against cold, its close fur, particularly upon the feet,
furnishing it with good protection ; and yet the winter form, as
it is called, or den of the hare, is a very snug little place. I had
* Gent. Mag. for June, 1782.
lv vya. Zenodotus ex Archiloch.
of Animals to secure Warmth. 503
once occasion to cross the wild mountainous tract on the north-
east boundary of Ayrshire, after a heavy fall of snow, which a
subsequent frost had hardened on the surface into a crust suffi-
cient to bear the foot without sinking. For several miles I did
not see a living creature; and even the hardy raven, that might
have fared sumptuously on the hapless sheep, many of which
had fallen victims to the weather, seemed to have abandoned
its summer haunts for the warmer vicinity perhaps of the sea-
coast. On crossing a small holm by the side of a brook, the
water of which I could hear running, though it was mantled over
with snow and invisible, I was not a little startled, — alarmed,
indeed, by a hare dashing through between my legs, and
almost upsetting me, and I found I had actually stepped over
her/orm before she was roused. The ancients had a notion
that the hare sleeps with its eyes open* ; and hence, Horus
Apollo says, the Egyptians pictured a sleeping hare as the
hieroglyphic of what was obvious.
1 The Greeks,' says Gesner, * had a common proverb (Layer
xa0et;$ov), " a sleeping hare," for a dissembler or counterfeit,
because the hare sees when she sleeps ; for this is an admirable
and rare work of nature, that all the residue of her bodily parts
take their rest, but the eye standeth continually sentinel f .'
The hare in question, however, must have been in a profounder
sleep than usual, — tempted, perhaps, by the supposed security
of its retreat in this almost untrodden wilderness. Upon
examining the /orra, I found it as neatly rounded as a bird's
nest, and of considerable depth, the foundation being a thick
tussock of withered rush (Juncus maximus), well lined with
bent, not carried thither, it would appear, but grown upon the
spot, and only beat down and arranged into a snug, circular,
basket-like cavity, just sufficient to contain the little animal,
when coiled up, to sleep. I could not ascertain whether it
had been quite open above, or partly covered with bent and
rushes, and curtained with snow ; but I think the latter most
probable, for had there been a speck of darker colour than the
uniform white surface around me- before I came to the spot, I
* Gesner, Hist. Anim,, by Toplis, p. 208.
t Ibid., p. 209.
2L2
504 Mr. Rennie on the Contrivances
could scarcely have failed to observe it. If such a covering,
however, had existed, it must have been destroyed at the exit
of the hare.
White of Selborne, in describing the severe season of 1776,
still remembered in popular chronology as the Frosty Harvest,
says, * the hares lay sullenly in their seats, and would not
move till compelled by hunger ; being conscious, poor animals,
that the drifts and heaps treacherously betray their footsteps,
and prove fatal*.' It is by no means unlikely that this was
the case with the hare which I started ; for I could perceive no
foot-prints to or from her little nest ; but if she did move out
to forage, she must have gone at least a couple of miles to
the nearest farmyard, at Whitehaugh, where she had every
chance to be shot while tasting the rip of corn usually hung
out about the hedges for this purpose ; in which way, indeed, I
had seen one killed the previous night at Waterhead farm. It
may be true, as the older authors affirm, that hares never feed
near home, e either,' says Gesner, ' because they are delighted
with foreign food, or else because they would exercise their
legs in going ; or else, by secret instinct of nature, to conceal
their forms and lodging-places unknown f.'
The great naturalist of the middle ages, Albertus Magnus,
says, that hares feed only in the night, because their heart
and blood is cold ; but evidently speaking, as was heretofore
the custom, on mere conjecture ; for the fact is well known,
and one of the most extraordinary in the animal economy,
though by no means as yet satisfactorily explained, that the
interior heat of quadrupeds varies extremely little in the coldest
and in the hottest climates. To the uneducated it appears no
less erroneous to say, that the body is equally warm on a cold
winter's morning as on the most sultry of the dog-days, as to
affirm the sun is stationary, contrary to the apparent evidence
of the senses, yet the one is as well ascertained as the other.
For example, Captain Parry found, that when the air was
from 3° to 32° at Winter Isle, lat. 66° ir N., the interior
temperature of the foxes when killed was from 106f° to 98° J ;
and at Ceylon, Dr. Davy found that the temperature of the
* Nat, Hist, of Selborne, lett. 1C6. f Gesner, as above, p. 209.
Second Voyage, p. 157,
of Animals to secure Warmth. 505
native inhabitants differed only about 1° or 2° from the ordi-
nary standard in England*. At very high temperatures,
however, there is a little more difference, as appears from the
ingenious experiments made by MM. Delaroche and Berger,
who exposed themselves to a heat of 228°, sixteen degrees
above that of boiling water: they ascertained that, at such
very high temperatures, there is an increase of seven or eight
degrees of the centigrade thermometer j. The increase of
cold, on the contrary, does not appear to influence the tem-
perature of the body in a similar way, and hence we discover the
cause why great cold proves less injurious and fatal to animals
than might be a priori anticipated. White of Selborne, speak-
ing of gipsies, says, ' these sturdy savages seem to pride them-
selves in braving the severity of the winter, and in living
sub dlo the whole year round. Last September was as wet a
month as ever was known ; and yet, during these deluges, did
a young gipsy girl lie in the midst of one of our hop-gardens,
on the cold ground, with nothing over her but a piece of a
blanket extended on a few hazel-rods, bent hoop fashion, and
stuck in the earth at each end, in circumstances too trying for
a cow in the same condition : within this garden there was a
large hop-kiln, into the chambers of which she might have
retired, had she thought shelter an object worthy her atten-
tion J.' The half wild cats, mentioned above, were more
attentive to their comforts than this young gipsy ; since a
neighbouring kiln for drying corn was their favourite resort
when the fire was lit.
The law by which animal temperature is thus maintained at
nearly the same degree on exposure to considerable heat or
cold, though it is not easy to reconcile it to any of the received
theories, supplies the only known reason why some of the
smaller and seemingly tender animals outlive the rigours of
our severest winters. The magpie (Pica caudata, RAY),
though rather a hardy bird, has been found having recourse to
what is often practised by smaller birds — several of them hud-
dling together during the night to keep each other warm. A
gentleman of intelligence and veracity informs me that he once
* Phil, Trans, for 1 814, p. 600. f Jour, de Physique, kxi. 289.
J Nat. Hist, of Selborue, lett, 67.
506 Mr. Rennie on the Contrivances
saw a number of these birds (probably a young family with
their parents) on a tree on a fir plantation sitting so closely
together that they all seemed to be rolled up into a single ball.
Little is known of the roosting of these birds ; but among
smaller species the habit in question is not uncommon. Even
during the day, in severe winter weather, I have observed a
similar practice in the house-sparrow (Passer domesticus, RAY).
On a chimney-top, which can be seen from my study window,
I have often remarked the whole of a neighbouring colony of
sparrows contest by the hour the warmest spot on the project-
ing brick ledge, which was in the middle. Here the sun shone
strongest, the kitchen-fire below sent its most powerful in-
fluence, and here the middlemost bird was best sheltered from
the frosty wind, which swept by its more unlucky companions
that had been jostled to the two extremities of the row ; but
none remained long in quiet: for as soon as the cold air pinched
them on the exposed side, off they popped to the middle,
scolding and cackling most vociferously, and, as those who
held the best places refused to give them up, the new comers
got upon their backs and insinuated themselves between two
of the obstinates, wedge-fashion, as you thrust a book into a
crowded shelf. The middle places were thus successively con-
tested, till hunger drove the whole colony to decamp in search
of food.
I once witnessed, near Eltham, a similar contest for places
among a family of the bottle- tit (Parus caudatus, RAY), whose
proceedings I had been watching, while they flitted from spray
to spray of a hawthorn hedge in search of the eggs of a coccus
(Coccus Cratcegi 9 FABR.). The ground was covered with
snow, and as evening approached, the little creatures, whose
restless activity had no doubt tended to keep them warm, re-
treated from the open hedge to the shelter of a thick holly ;
' the leading bird,' as Mr. Knapp correctly describes, * uttering
a shrill cry of twit, twit, tunt, and away they all scuttled to be
first, stopping for a second, and then away again *.' When
they, had all assembled, however, on an under bough of the
holly, they began to crowd together, fidgeting and wedging
* Journal of a Naturalist, p. 164. Third edition.
of Animals to secure Warmth. 507
themselves between one another, as the sparrows had done ;
but whether they intended to roost there, or were merely set-
tling the order of precedence before retiring into some hole in
the tree, I did not ascertain, for, in my eagerness to observe,
I approached so near as to alarm them, and they all flew
off to a distant field.
That the contest for places among the little bottle-tits was
only previous to retreating into some more snug corner for the
night, appears to me probable, from the known habits of their
congeners, and also from what I daily observe among sparrows.
Every evening before going into their roosting holes, the latter
assemble on some adjacent tree or house-top, squabbling and
shifting places for a considerable time, and then dropping off,
one by one, according as they seem to have agreed upon the
etiquette of precedence. Hardy as they certainly are, spar-
rows manifest great dislike to exposure during the night, and,
accordingly, they may be observed taking advantage of every
variety of shelter. They are most commonly seen, indeed,
creeping under the eaves of houses, or the cornices of pillars,
but they are equally fond of a hole in a hay-stack, of getting
under the lee-side of a rook's nest on a lofty tree, or of pop-
ping into a sand-hole burrowed out for its nest by the bank
swallow (Hirundo riparia, RAY).
But while I am disposed to give sparrows all due credit for
their tact in discovering the warmest and best sheltered roost-
ing places, I am convinced that White of Selborne attributes
to them more intelligence than can be verified by facts.
* House-sparrows,' he says, ' build under eaves in the spring ;
as the weather becomes hotter, they get out for coolness, and
nest in plum trees and apple trees*.' Dr. Darwin, on the
other hand, imagined that the sparrows betake themselves to
trees when they cannot find convenient holes, and, therefore,
mentions as a singular circumstance, that ' in the trees before
Mr. Levet's house in Lichfield, there are annually nests built
by sparrows ; a bird/ he adds, ' which usually builds under
the tiles of houses or the thatch of barasf ;' while M. Bonnet,
taking a directly opposite view, says, ' II 1'etablit pour, Vordi-
* Letter 60. f Zoonomia, i. xvi, 13, 2.
508 Mr. Rennie on the Contrivances
naire, au sommet des arbres — et lorsqu'il batit son nid sous les
tuiles ou sous les entablemens des edifices, il se dispense des
frais de la calotte, qui serait, dans ce cas, tres-superflue *.'
The truth seems to be, that the sparrow does not give itself
much trouble in selecting its abode, depending on its industry
and ingenuity for rendering, by means of a mass of hay and
feathers, the bare branch of a tree as warm as a hole in a hay-
stack or a burrow of the bank-swallow ; and, accordingly,
there may be observed, at least near London, about an equal
number of sparrows nestling on trees, and under various sorts
of shelter, and not at all, so far as I can perceive, influenced,
as White would have it, by cold or warm weather.
Mr. Leonard Knapp, in conformity with the latter view,
gives a very different account of the alleged intelligence of
birds, in the instance both of the thrush family (Merulida,
VIGORS) and the sparrow. ' Birds/ he says, ' that build early
in the spring seem to require warmth arid shelter for their
young ; and the blackbird and thrush line their nests with a
plaster of loam f , perfectly excluding by these cottage-like
walls the keen icy gales of our opening year ; yet, should acci-
dent bereave the parents of their first hopes, they will con-
struct another, even when summer is far advanced, upon the
model of their first erection, and with the same precautions
against severe weather, when all necessity for such provision
has ceased, and the usual temperature of the season rather
requires coolness and a free circulation of air. The house-
sparrow,' he adds, ' will commonly build four or five times in
the year, and in a variety of situations, under the warm eaves
of our houses and our sheds, the branch of the clustered fir,
or the thick tall hedge that bounds our garden, &c. ; in all
which places, and without the least consideration of site J or
season, it will collect a great mass of straw and hay, and
gather a profusion of feathers from the poultry yard to line its
nest. This cradle for its young, whether under our tiles in
* Contemplation de la Nature, ch. 28, note 6.
f This is a mistake: the thrush never uses loam, but forms her plaster of horse or
cow-dung and fibres of rotten wood cemented with saliva, as I have proved by
examining numerous specimens of the nests.
I This is at variance with the above extract from Bonnet, as well as with my
observation.
of Animals to secure Warmth. 509
March or July, when the parent bird is panting in the common
heat of the atmosphere, has the same provisions made to
afford warmth to the brood*.'
So true is this of the thrush and the' blackbird (Merula
vulgaris, RAY), that in the early spring they seem not even to
take the usual precautions for concealment, as I have often
seen these nests in leafless bushes : a thrush's I particularly
recollect observing near Blarney- Castle, in Ireland, about
the end of March, when the winds were almost as biting and
cold as in January, placed in the naked fork of a young oak.
In accordance with their usual instinct, the mother-bird was
so afraid of exposing her eggs to the cold wind, that she
suffered me almost to touch her before she would stir from her
place. This family of birds, however, though so careful to
provide shelter and warmth for their eggs and young, shew no
wisdom in procuring the same comforts for themselves during
winter, as they usually roost along with red-wings and chaf-
finches in the open hedges, where they are often frozen to
death in severe weather f, or are captured by bat-fowlers.
The starling (Sturnus vulyaris, LINN.) exhibits more care for
itself, by roosting in the holes of trees, in the towers of
churches, or under the tiles of an old house, like the sparrow,
and frequently among the thick tops of reeds, in marshes.
Yet will they sometimes suffer from frost even there ; and one
winter's day in 1822, after a very keen frost in the night, when
I was searching for lichens on the trees in Copenhagen-fields,
I found a cock starling lying in a hole, frozen to death. It
was in very fine condition, and more perfect in plumage than
1 ever saw this species ; but it did not appear, upon the closest
examination, to have received any shot or other injury to
cause its death besides the effects of the frost.
It may be remarked, that, like the sparrows and other birds
which roost in holes, the starlings huddle closely together, con-
tending for places, a circumstance, indeed, recorded by Pliny.
( As touching sterlings,' says he, ' it is the property of the
whole kind of them to flie by troups, and in their flight to
gather round into a ring or ball, whiles every one of them hath
* Journal of a Naturalist, p. 167. Third edition.
f White's Selburne, letter 150.
510 Mr. Rennie on the Contrivances
a desire to be in the middest *,' corresponding exactly with
what I have above mentioned of the sparrows and bottle-tits.
It is not a little interesting thus to verify facts which were
observed by the ancients ; and Mr. Knapp has done so in the
instance of the starling now under consideration. * There is
something,' he remarks, 6 singularly curious and mysterious
in the conduct of these birds previous to their nightly retire-
ment, by the variety and intricacy of the evolutions they
execute at that time. They will form themselves, perhaps,
into a triangle, then shoot into a long, pear-shaped figure, ex-
pand like a sheet, wheel into a ball, as Pliny observes, each
individual striving to get into the centre, &c., with a prompti-
tude more like parade movements than the actions of birds f .'
In the instance of the redbreast, the hedge-sparrow (Accentor
modularist BECHSTEIN), and the wren (Anorthura communis,
Mini), one can scarcely imagine how any of the species
survive the winter, were it no more than the difficulty of pro-
curing food. Selby, indeed, has observed wrens to perish in
severe winters, particularly when accompanied with great falls
of snow. ' Under these circumstances/ he says, ' they retire
for shelter into holes of walls, and to the eaves of corn and
haystacks ; and I have frequently found the bodies of several
together in old nests, which they had entered for additional
warmth and protection during severe storms J.'
My friend, Allan Cunningham, tells me that he once
found several wrens in the hole of a wall, rolled up into a sort
of ball, for the purpose, no doubt, of keeping one another
warm during the night ; and though such circumstances are
only observed by rare accident, I think it very likely to be
nothing uncommon among such small birds as have little
power of generating or retaining heat in cold weather. This
very circumstance, indeed, was observed by the older na-
turalists. Speaking of wrens, the learned author of the
Phy sices Curiosce says, they crowd into a cave during winter
to increase their heat by companionship : * Multi uno specu in
hyeme conduntur, ut parvus in tarn minutis corporibus color
* Natural Historic, by P. Holland, p. 284. Ed. 1634.
f Jour, of a Naturalist, p. 195.
I Illustrations of Brit, Ornith. i, 197.
of Animals to secure Warmth. 511
societate augeatur *.' The value of this author's testimony,
however, may be estimated by his adding, that when wrens
are put upon a spit to roast, it turns of its own accord ; a fact
which he professes to have himself witnessed, in company
with the celebrated Kircher, at Rome, they being commanded
to try the experiment by a certain eminent cardinal, who fur-
nished the bird, and a hazel rod for a spit. At first they
despaired of success ; but just as Kircher, who had lost all
patience, was going away, the spit (mirabile dictu /) began to
turn slowlyj* ! ! Those who keep wrens in cages, usually furnish
them with a box, lined and covered with cloth, having a hole
for entrance, where they may roost warmly during the night J.
Yet even in keen frost the wren does not seem, in the day-
time, to care much for cold, since I have, in such cases,
frequently heard it singing as merrily as if it had been enjoying
the sunshine of summer ; contrary to the remark of White,
that wrens do not sing in frosty weather §.
It is in a similar way that the cold is braved by the tiny har-
vest mouse (Musmessorius, PENNANT), the least of our British
quadrupeds, which only weighs about an eighth of an ounce,
and measures two inches and a half, exclusive of the tail.
This little creature does not appear to become torpid like some
of the same order of animals ; but a party of them assemble at
the close of autumn, dig a deep burrow to contain their colony,
and, collecting a competent stock of provisions for their com-
mon use, they crowd together, as we have seen some species of
birds do, to economize their animal heat by sharing it in com-
mon. We are not sufficiently acquainted with the winter
habits of several others of our little quadrupeds — such as the
water-shrew (Sorex fodiens) — to say how they pass the winter,
though it is not improbable they adopt some similar method to
the one just mentioned, as they are not known to become
torpid. The only notice we possess of the water-shrew is
one by an ingenious living observer, Mr. Dovaston, of Shrews-
bury, who saw one in April burying itself under some leaves,
at the bottom of a pool. White records an instance of the
water rat (Mus aquaticusy MERRET), as having a winter cell
* Phys. Curiosae, p. 1249. ± Syme, Brit. Song Birds, p. 159.
Ltjdem,ib. $ Selborne, let. CO.
512 Mr. Rennie on the Contrivances
in a dry chalky field, far from water, artificially formed of
grass and leaves, and containing above a gallon of potatoes
regularly stowed ; but whether this is done by its congeners
remains to be discovered.
The retreat of the dormouse (Myoxis avellanarius, FLE-
MING) is better known. These little creatures provide a store
of nuts and grain, and retire to holes at the bottom of hedges
and trees, where they commonly lie torpid in cold weather,
but in mild winters remain awake and feed on their stores, in
the same manner as the squirrel. In the winter I have found
great numbers of their nests, about four or five feet from the
ground, in hedges and hazel copses, and 1 imagined it possible
that some individuals might winter there almost as snugly as
under ground ; for.they are constructed with a great quantity
of dry grass leaves, well wound together, with no perceptible
opening ; but among at least fifty of those which I have
examined, I found no inhabitants, and, therefore, conclude
that they are only built to protect the young during our colder
summer nights, and placed high in the bushes, to be somewhat
out of the reach of cats and weasels.
Having recently had occasion to investigate the structure of
various nests with some minuteness, I have been led to adopt
the opinion, that the arched coping or dome, — so remarkable
in several small birds for ingenious and beautiful workmanship,
— is designed to preserve their animal heat from being dissi-
pated during the process of incubation — an opinion which
appears corroborated by our native birds that thus cover in
their nests at top being all very small. Among these are the
common wren, the wood wren (Sylvia sibilatrix, BECHSTEIN),
the hay bird (S. trochilus), the chiff-chaff ($. hipola'is), the
gold-crested wren, the bottle-tit (Parus caudatus, RAY), and
the dipper (Cinclus aquaticus, BECHSTEIN). There are other
birds, no doubt, a little larger than these, such as the black-
cap and the babillard (Curruca garrula, BRISSON), which do
not build domed nests ; but it is worthy of remark that the
latter usually lay much fewer eggs, — the babillard seldom more
than four, and the blackcap four or five; while the gold-
crested wren lays from seven to ten, the bottle-tit from nine to
twelve, and common wren from eight to (some say) fourteen
ofAnimah to secure Warmth. 5J.3
and even twenty. It will follow, of course, that, in order to
hatch so large a number, these little birds require all their
animal heat to be concentrated and preserved from being dis-
sipated. The dipper, indeed, lays but five or six eggs, and
weighs from six to eight times more than any of our other
dome-builders ; but it is to be recollected that its being a water
bird, and building near water, it may have more occasion to
use ' all appliances ' to concentrate its heat. Such are some
of the circumstances which occur to me corroborative of the
opinion.
On the other hand, it may be alleged, that there are more
birds in tropical countries which cover their nests with domes,
than among our European natives*. I would account for
this, however, on the principle of procuring shade, in the same
way as our sailors put up an awning on deck in tropical lati-
tudes ; for birds, constantly sitting on their eggs during incu-
bation, must in these countries be frequently exposed to the
rays of a vertical sun, which could scarcely fail to prove in-
jurious. I am well aware that it is the received opinion, these
covered nests are designed to protect the eggs and young from
snakes ; but this mistaken notion has been adopted, without
taking into account the natural habits of the accused snakes —
the smaller ones of which would more readily pry into a nest
with a narrow hole for a side entrance, than into an uncovered
nest. In the instance of a domed nest of the hay-bird (Sylvia
trochilus'), with which I was acquainted last summer, 1 found
a large snake (Coluber natrix) lying close by it, and the eggs
untouched ; but as it had just swallowed a large frog, which it
disgorged upon being caught, it might, probably, have no ap-
petite at this time for the hay-bird's eggs.
The same anxiety to secure warmth by preventing the dissi-
pation of animal heat evidently actuates the wild animals
which pass the winter where snow is either permanent or par-
tial. Some of these, such as the marmot (Ardomys Mar-
mota, A. Bobacy &c.), lie several weeks or months torpid in
cells, previously prepared with no little care. This prepara-
tion of a winter abode has always excited admiration ; and
* Prince Maximilian's Travels in Brazil, p. 105
514 Mr. Rennie on the Contrivances
hence, as is usual in such cases, it has been exaggerated by
the fancies of inaccurate observers. ' Their wit and under-
standing,' says Gesner, * is to be admired ; for, like beavers,
one of them falleth on the back, and the residue load his belly
with the carriage, and when they have laid upon him sufficient,
he girteth it fast by taking his tail in his mouth, and so the
residue draw him into the cave ;' — « but I cannot,' he well
adds, * affirm certainly, whether this be truth or falsehood ; for
there is no reason that leadeth thereunto, but that some of
them have been found bald on the back*.' I should not have
alluded to this evident fable here, were it not that it is still
met with in recent scientific publications, gravely stated as an
ascertained fact ; and M. Beauplan goes so far as to imagine
that he has seen a party trailing one of their loaded com-
panions by the tail, taking care not to overset him f . This
feat, however, seems to be outdone by the legend lately given
as authentic of the marmot's skill in haymaking. ' They bite
off the grass,' it is said, ' turn it, and dry it in the sun J ;'
stories too absurd for the almost indiscriminating credulity of
either Linnaeus or Buflfon, both of whom reject them.
But even several animals which do not become torpid, and
provide no hay-lined cell as a snug retreat from the cold, con-
trive to prevent the dissipation of their animal heat by retreat-
ing under the snow itself, taking advantage of the covering
furnished by Providence for the protection of vegetables. The
latter is beautifully illustrated, as it appears to me, by what
occurs in the cultivation of Alpine plants in our gardens, many
of which, such as auriculas, some saxifrages, &c., are not
unfrequently destroyed or rendered unhealthy by our winters,
whilst they flourish amidst their native snow ; wholly, it is
probable, because, in the Alps, where they are growing wild,
they are throughout the winter covered with a complete coat-
ing of snow, which, from not being a rapid conductor of heat,
is instrumental in the earth's not parting quickly with its
warmth, in the same manner as woollen garments prevent the
escape of heat from the body ; this protects them through the
* Hist. Animals, by Toplis, p. 407.
t Descript. Ukraine.
I London and Medical Gazette for 1828, and Mag. of Nat. Hist, i.377,
of Animals to secure Warmth. 515
cold season. Whereas, in our climate, these plants are ex-
posed alternately to the severe influence of frost (unprotected
by the covering of snow), and to long continued rains. Even
during the winter months our plants frequently commence
growing before the spring arrives, and thus are rendered more
obnoxious to the succeeding frosts ; and, in addition, the chief
strength of the plants (which should be reserved for the great
effort to be made in the spring) is exhausted before its due
season, whilst, in the Alps, they lie entirely dormant until the
sun at once melts the snow, and calls them into life and
blossom. Gardeners, accordingly, in the cultivation of the
finer sorts of auriculas, &c., have to imitate, as far as possible,
their native climate, by protecting them in a frame or shed
both from the severe frosts and wet.
Amongst the animals which take advantage of the non-
conducting property of snow, the white grous, or ptarmigan
(Lagopus vulgaris, FLEM.), may be mentioned, which will
burrow under the drifted wreaths, picking up a scanty subsist-
ence among the herbage and seeds of heath for many weeks.
This, indeed, may be considered one of its destined and regular
habits * ; and it no doubt feels as comfortable while it is pro-
tected from the keen frosty gales of the mountain by its
snowy canopy, as does the partridge of the low country
when skulking for a similar purpose under the lee side
of a hedge ; but there are two other native species of
grous, the black cock (Tetrao Tetrix), and the moor fowl
(Lagopus Scoticus, FLEM.) ; the latter peculiar to Britain,
which only resort to the same expedient when forced by acci-
dent. The common shelter of both of these is the higher and
more bushy clumps of heath (Calluna vulgaris, HOOKER) ;
but when these, as occasionally happens in most winters, be-
come covered with snow, the grous find it convenient to
remain under cover rather than venture abroad where they
have less chance of meeting with food and shelter.
It appears to arise from some instinctive presentiment of the
same kind, that sheep, during a snow-storm, always flee to the
nearest shelter, though this is certain to end in their destruc-
* See Olaus Magnus, Hist. Septentrion, xix. 33, for an interesting account of
the mode of hunting these birds.
510 Mr. Rennie on the Contrivances
tion, if the snow fall deep and lie long ; it therefore becomes
one of the most painful tasks of the shepherd in such circum-
stances to keep his sheep steadily in the very brunt of the blast.
This I was at least told by an old shepherd whom I encoun-
tered at night-fall the end of December, 1808, in a wild moun-
tainous pass, near Douglas, on the borders of Lanarkshire,
who was actually engaged in thus guarding his flock in as heavy
a fall of snow as I recollect ever witnessing. The Ettrick
Shepherd, in an intensely interesting narrative, entitled
* Snow Storms/ in his Shepherd's Calendar, does not allude to
this propensity in sheep ; though it may be inferred that they
had acted upon it, from his having found a number buried
under the snow by the side of a high bank, under which, no
doubt, they had fled for shelter, at the onset of the storm.
Though sheep, from their mode of life, ought to be hardy, they
exhibit an anxiety for procuring shelter well worthy of remark.
It is mentioned by Lord Kames*, that the ewe, several weeks
before yeaning, selects some sheltered spot where she may
drop her lamb with the most comfort and security ; and Hogg,
in the volume just referred to, gives an instance in which a ewe
travelled to a great distance to the spot where she had been
accustomed to drop her lambs ; but what was still more remark-
able, a ewe, the offspring of this ewe, though removed to a
distance when a few days old, returned to the same spot to
drop her first lambf .
The care taken by insects for warmth is shewn by the early
appearance of some species. Although few insects are seen
during cold weather, yet on fine days some are always stirring;
but it is much less wonderful to see the larger butterflies (Va-
nessa Urticce, Gonepteryx Rhamni, &c.) braving the cold, in-
asmuch as their bodies and wings are warmly clothed with
down and feathers, than some of the more delicate moths
(Tortricida, Tineadcs) which appear to be far less comfortably
clothed. The common hive-bees, when tempted by a glimpse
of sunshine to leave their hive, frequently perish of cold before
they can effect their return, though they also have a tolerably
thick coat of hair for their defence. This early appearance of
bees, however, as well as of some butterflies, may be considered
* G^ntltmau Farmer, p. 45. f Shepherd's Calendar, Chapter on Sheep.
of Animals to secure Warmth. 517
as accidental rather than according to the usual order of things;
but there are several insects whose regular time of appearance
is fixed by nature in the first months of the year, pro-
bably for the purpose of supplying a scanty meal, to such of
the soft-billed birds as are permanent residents, the berries on
which they have in part subsisted being now useless or exhausted.
Amongst these we may reckon the small egger-moth (Eriogas-
terlanestris), which is disclosed towards the end of February,
having lain from the preceding July in a pupa case similar to
plaster of Paris in consistence and appearance. The moth
itself is but of middle size, and is pretty closely covered, particu-
larly on the body, with hair. Its inconspicuous chocolate-brown
colour might furnish the advocates for concealment in respect
of colour with a very good illustration.
The little gnat ( Trichocera hiemalis, MEIGEN), which may be
seen in troops during winter weaving eccentric dances in the
air even when the ground is covered with snow, flies for shelter,
as I have frequently found, to the hollow stems of umbelliferous
plants and similar places near its usual haunts. A much
smaller and more delicate fly, which has not a little puzzled
systematic naturalists to class (^leyrodes Chelidonii, LA.-
TREILLE), preserves itself from the cold in a similar manner.
This species is so small, that it would not cover the area of a
pin's head, and its snow white wings, as well as its elegant form,
might entitle it to the appellation of the mite-butterfly; yet so
well does this tiny creature know how to avoid cold, that, after
the severe winter of 1829-30, I found three of them sporting
about in March in Shooter's-hill Wood, as lively as if no frost
had occurred.
During the previous frost in that season, I opened two nests
of the yellow ant (Formica flava), in which the inhabitants
•were by no means torpid or inactive, although not so lively as
in summer ; but these nests had been carefully constructed in a
peculiarly warm situation, being both in the trunks of old
willows, rendered quite spongy by dry-rot, and facing the souih-
west, where they had the benefit of every glimpse of sunshine.
Ants, indeed, exhibit the most extraordinary tact in attending
to variations of temperature, so much so, that they might, in a
glazed formicary, constructed upon Huber's plan, be made to
VOL. I. MAY, 1831. 2 M
518 Mr. Rennie on the Contrivances
serve the purpose of a thermometer. Sir Edward King, an
excellent naturalist, who lived in the time of King Charles II.,
seems to have been the first to discover this peculiarity : —
' I have observed,' says he, ' in summer, that in the morning
they bring up those of their young, called ants-eggs (cocoons),
towards the top of the bank, so that you may, from ten o'clock
till five or six in the afternoon, find them near the top, for the
most part on the south side. But towards seven or eight at
night, if it be cool, or likely to rain, you may dig a foot deep
before you can find them *.' Ants, during winter, unques-
tionably manifest more intelligence, instinct, or whatever it
may be termed, than bees ; for the hive-bee will rashly venture
abroad on the occurrence of a mild day, or even of a few
hours' warm sunshine, when the ground is covered with snow ;
but I have never observed ants, either in the colonies naturally
established, nor in the artificial formicaries that I have kept,
tempted to venture abroad before the return of spring. The
result is, that the bees (foolish in this instance, though wise in
so many others) frequently perish from their rashness ; while
the ants are snug in their cells. This is the more surprising,
that in the instance of swarming bees appear to be uniformly
regulated by the temperature of the weather, and will not
leave the original colony when the air is below a certain
degree.
While I was concluding this paragraph, I was, by accident,
furnished with an example of the contrivances in question in a
well known insect — the flea (Pulex irritans), which chanced
to leap upon my paper, and, as I took care not to disturb it, I
observed it attempting to dig a burrow with its beak. To this
task, I have no doubt, it was sufficiently equal; but after
working into the paper, so as to make a perceptible hole, it
abandoned the spot, as if it did not like the material. After
skipping about for some time, it settled on the green cloth
cover of my desk, where it again made an attempt to burrow ;
and I remarked that, in this case, contrary to its mode of
working on the paper, it threw itself on its back, pushing the
wool upwards with its feet, and downwards with its shoulders,
* Phil. Trans. No. xxiii. p. 425-7.
of Animals to secure Warmth. 519
till it wedged itself into the nap quite out of sight, intending of
course to lie snug and warm till hunger should prompt it upon
a foraging excursion. I am well aware that observations like
this have drawn forth the ridicule of witlings, who have repre-
sented naturalists as little better than children or idiots ; but,
if the Great Creator did not think it beneath him to adapt, with
wonderful skill, the structure of a flea to its mode of life, it can
never be a trifling study to observe and admire such instances
of his providential wisdom.
Many other illustrations of the attention of animals to secure
warmth crowd upon my recollection ; but, as this paper may
already be deemed too tedious, I shall, for the present, forbear
to go into further detail.
Lee, Kent, March 7th, 1831.
ON THE AURORA BOREALIS OF THE 7th OF
JANUARY, 1831.
BY DR. MOLL, OF UTRECHT.
many years the beautiful phenomenon of the Aurora
Borealis has been of very rare occurrence in this country ;
so much so, indeed, that I do not recollect having seen it more
than once, and that was in 1828, and even then it was in
England. During the time of the late Professor Van Swin-
den's residence in the University of Franeker, between 1766
and 1784, particularly in 1769, 1772, 1773, and 1777, it was
very frequently witnessed by that diligent and accurate ob-
server, and his observations are well known to the scientific
world. Since that period, it scarcely ever shone in all its
splendour; and now and then only its existence in more
northern regions has been announced to us by some faint
coruscations near the boreal part of the horizon.
On the 7th of January last a beautiful exhibition of this
phenomenon was witnessed here between 6 and 10 P.M., the
effect of which was particularly striking. The sky was very
clear and transparent ; the stars were remarkably bright 5
Cassiopea nearly in the zenith ; Orion ascending in all
its glory towards the meridian ; Procyon standing in the
2 M 2
520 Dr. Moll on the Aurora Borealis.
east, whilst Lyra and the Swan descended towards the ho-
rizon in the N.W. The air was very calm : after some
days of thaw the weather had become frosty. The thermo-
meter, during the time of the phenomenon, ranging between
26° and 24° Fahr. The little breeze there was blew from
the S.E.
From the S.W. to the N.E. a bright arch of whitish light
extended itself through the firmament, its width being about
10° or 12°. This luminous arch passed through the zenith, a
little to the northward of the Pleiades. Its light was of a white
colour, and uniform throughout. Shortly after, a second
similar arch sprang up to the north side of the first. From
the S.W. to the N.E. a column of light arose in an oblique
direction ; a similar one formed in the zenith ; these three
columns joining together, and thus a double arch of unparal-
leled beauty illuminated the heavens, whose continual corus-
cations formed a most extraordinary spectacle. To the south
of this arch, in that part of the sky where Orion then was,
and somewhat lower than y and a of that constellation, and
near the Eagle and Dolphin, the firmament was of a dark
blue ; and Orion, glittering on this dark ground, shone in
beautiful contrast with the vivid light of the luminous arch.
The appearance of this arch or luminous belt lasted only a
few minutes : it began first to fade in that part of the air
whence it arose in the beginning. In the N.W. the air was
illuminated as if by the crepuscule of a summer's night.
Being then in the country, I hastened to an open field,
where the view of the horizon in the north was not impeded
by buildings. There, in the north, that luminous circular
arch, which is so frequently mentioned by writers on the Aurora
Borealis, was splendidly visible." I would rather call it a seg-
ment of a circle, of which the horizon was the chord. The
bright star a Lyra was nearly in the middle of this segment,
and it extended as far northward as the tail of Ursa Major.
Under this luminous arch the sky was somewhat blacker ; but
I did not observe under it that dark part which frequently
occurs in descriptions of the Aurora Borealis. From out of this
luminous arch, as if from its centre, rays of tremulous white
light were incessantly springing up in all directions ; of these
Dr. Moll on the Aurora Borealis. 521
rays have been often (not unjustly) compared to the sticks of
a fan. Sometimes these rays ascended nearly as high as the
zenith, then disappeared, and were succeeded by others. The
space between the columns was frequently of a beautiful rose-
colour.
In about half an hour the flame-like rays ceased to rise from
the luminous segment in the N.W. ; but the segment still
continued to shine with a softer light.
At about nine o'clock the beautiful appearance called by
authors on the Aurora, the Pavilion, was displayed. From
the zenith, large and bright streams of flame-like light de-
scended towards the S.W., N.E., N. and N.W. in splendid
succession ; and the view they afforded was sublime arid mag-
nificent beyond description. The N.W. part of the firmament
was now covered with coruscations of glowing red light, con-
tinually varying in appearance. The brown heath on which
I walked was so illuminated as to make objects appear per-
fectly distinct, even at some distance.
During the vivid and sudden changes of these luminous
flashes, a single mass of light, like a cloud, arose from the
N.E. towards the zenith, passing in quick motion very near the
Pleiades, and disappearing in the S.E. This orb of light,
through which the stars were visible, was round and globulous
in the fore-part, and terminated in a flaming, tapering tail.
Its appearance was short and very striking. It was a glorious
illustration of the truth of Lucan's description : —
Ignota viderunt obscurae sidera noctes ;
Ardentemque polum flamrais ; coeloque volantes
Obliquas per inane faces.
The phenomenon disappeared gradually ; the Pavilion lasted
but a short time : at about ten o'clock the luminous arch alone
remained visible in the N.W. ; this continued during several
hours, till the wonted darkness of night was entirely restored.
The next day the weather was thawing apd snowy, the
wind S.E. The sky, however, seemed in the night following
somewhat brighter in the N.W.
The following is the abstract of the barometric and ther-
mometric observations some days before and after the Aurora
Borealis.
522 Dr. Moll on the Aurora Borealis.
OBSERVATORY, UTRECHT.
Hour. Barom. Therm. Weather. Wind*.
H. M. Inch.
1831, Jan. 5.— 2 33 . 29.807 . 31.3 . Foggy. . Calm.
6.— 6 8 . 30.083 . 32.6 . Thawy. . N.N.E.
7.— 1 34 . 30.500 . 29.3 . Very clear. N. afterwards S.E.
8.— 2 48 . 30.400- . 29.9 Hail and Snow. S.S.W.
9.— 2 42 . 29.963 . 36.8 . Cloudy. W.S.W
On the 3d of March, 1821, when a shock of earthquake
was felt at Dover and the neighbouring places, nothing in the
atmospheric state indicated in this country that anything ex-
traordinary was happening at so short a distance. At about
4 P.M. the barometer stood at 29° 520', the thermometer
at 47° 3'. The air was dark and overcast ; it blew a strong
gale from the W.S.W.
OBSERVATIONS ON THE AURORA BOREALIS OF THE
7th OF JANUARY, THE llth OF JANUARY, AND
THE 7th OF MARCH, 1831.
BY THE HON. CHARLES HARRIS.
FN consequence of the account of the Aurora Borealis of the
7th of January, given by Mr. Christie in the last Number
of this Journal, we have been favoured, by the Hon. Mr.
Harris, with the following extracts from his Meteorological
Journal, kept at Heron Court.
Friday, January 1th, 1831. — Magnificent Aurora Borealis
at night. It first appeared about 5h 30m P.M., in the shape of
a white cloud in the north, 10° in depth and 55° high, extend-
ing from west to east, much denser towards its extremities,
where it was edged off with prismatic tints of red and green.
It seemed coming over from N., and a narrow band of it passed
over as far as about 20° on the south of the zenith. In the
north it soon became traversed with bright columns, with here
and there a hazy patch of flame colour, especially in the N.W.
It was most beautiful about nine P.M., when the cloud came
nearly over head, being driven, as it were, by the wind from
the north. Its eastern extremity, which was very dense and
luminous, drove by as far as E.S.E. Suddenly, however, it
streamed back again, in bright streaks, towards due north, look-
Mr. Harris on the Aurora Boreali*. 523
ing as if the fiery cloud had burst. In the midst of these streaks
appeared bright patches, especially N.E., of the most brilliant
flame colour. At one time, these united and formed a most
beautiful track of pale crimson from N.W. to N.E., the flame
colour in some places occurring outside the white cloud against
the clear sky. The northern edge of the cloud gradually
became dense and ragged, while the sky in the north, to the
height of twenty degrees, was of the most inky blackness.
Excepting the bright prismatic patches of crimson, faint green,
and sometimes yellow, it had all the appearance of a spent
snow-squall strongly lighted by the moon. By ten P.M. the
light gradually withdrew from the zenith, and settled very like
a bank of cloud, extending from west to east, about 10° in
depth, the sky beneath, for 20°, being perfectly black. In the
brightest parts of the cloud the stars were seen, but faintly ;
and, indeed, Ursa Major, at one time, was scarcely visible.
The thermometer at the time 24°, barometer 30.60.
Tuesday llth. — Aurora Borealis visible at eight. About
8h P.M. it appeared in the form of two horizontal luminous
bands of cloud, about 20° high, and extending from N.W.
to N.E., with a distinct dark space intervening. About 8h
30m they were rendered more confused by a hazy white light
streaming up through them from the north, giving the luminous
strata the appearance which geologists call * a fault.' The
eastern edge of the light was very clearly defined: indeed
it had the appearance of a strong light streaming through a
half-closed aperture. Barometer 30.03, thermometer about 30Q.
At nine P.M. the night became cloudy, and no observation
could be made.
Monday, March 1th. — Aurora Borealis very fine at night. I,
observed it first about 8h 40m P.M. Its lower edge then formed
a very regular arch from N.W. by W. to N.E. ; the greatest
altitude of which was in N.N.W., about 18°. A large star
(Deneb in Cygnus about N. by W. ?) was 2° above its lower
edge. The light suddenly seemed to become concentrated in
the N.E., where the lower edge became irregular and ap-
proached the horizon like the folds of a curtain ; at the same
time three or four streams of vertical white light shot up in the
N.E., N.N.E., and N, : these almost immediately faded away ;
524 Mr. Harris on the Aurora Borealis.
the Aurora became as before, the light becoming insensibly
fainter from the lower edge to about 45°, where it was no
longer perceived. After the coruscations in the N.E., the
main body of light seemed to move rapidly to the westward,
the whole phenomenon, however, becoming much brighter.
The lower edge again became ragged, and approached the
horizon ; and in the W.N.W. brilliant columns of light, tinged
with pale flame colour, shot up to the altitude of 50°. From
this time to about 9h 15m the Aurora was in its greatest
beauty ; a large body of light appearing constantly travelling
from N.W. to N., and vice versa. Whenever coruscations
were about to be thrown up, the lower edge of the cloud be-
came like the base of a thunder-shower, the ragged points
being at times brilliantly luminous : from these points the
columns of light shot up with great intensity. About 9h 15m
a most splendid coruscation shot up from due N. It appeared
to extend down to the horizon, and shot up to the height of
about 50°, the column itself being 4° wide. The upper ex-
tremity, and, indeed, the greater part of the sky from N. to
W.N.W. , at the height of about 55°, was of a beautiful pale
flame colour. Beautiful columns of light were at the same
time shooting up from the N.W. and N.N.W., and faint
nebulae of light were visible about 10° to 15° N. of the zenith ;
the Aurora then again faded into a large luminous track from
N.W. to N.E., and its lower edge but ill defined : the flame-
colour remained for some time on the upper edge. Small
cirostrati in the N. and N.E. were thrown out in the most
striking relief; and at 9b 15m Deneb was, for a few seconds,
but faintly visible. The light against the north side of a house
was as strong as that of the moon at the quarter. At 10h P.M.
the Aurora was very faint ; its lower edge about 7° from the
horizon, from which the light gradually faded off, and was
faintly perceptible at 45°. The sky beneath, however, was of
that inky blackness so peculiar to this phenomenon. Barometer,
9 P.M., 29.82, thermometer 40.5. About 4 P.M., in the N.E.
and N.W., a thin brown haze was visible, a very unusual cir-
cumstance, with a westerly wind and in unsettled weather ; the
haze split off at times in horizontal tiers, and it was impossible
to discover whether it was haze or distant cirrus; indeed,
Mr. Harris on the Aurora Borealis. 525
it was this that induced me to look out ; and I have little
doubt, from a similar circumstance mentioned by Parry in his
first Tour, that this was the daylight appearance of the Aurora.
ON THE HEIGHT ABOVE THE SURFACE OF THE EARTH
OF A LUMINOUS ARCH OF THE AURORA BOREALTS,
ON THE 7th OF JANUARY, 1831.
BY S. H. CHRISTIE, ESQ., M.A., F.R.S., &c.
HPHE height of the Aurora Borealis above the surface of the
earth has been so variously estimated, that any observa-
vations which determine limits to the height of a particular
phenomenon become interesting, although these limits may not
be extremely close. The most permanent of the phenomena
are the luminous arches, and these are therefore the best
adapted for determining the height ; but even these appear to
be by no means stationary : and as more than one are some-
times visible, it may, in many cases, be doubtful, whether
simultaneous observations, made by distant observers, refer to
the same arch. The Aurora of the 7th of January last made
its first appearance in this neighbourhood, in the south-east,
and in a few minutes afterwards, a single well-defined arch,
and which was visible but for a short time, was formed across
the southern meridian. If then the commencement of the
Aurora happened to be observed, in the form of an arch, at a
considerable distance to the south of the place where I observed
the altitude of the arch, there could be scarcely any doubt of
the identity of the luminous band forming these arches. It
appears from Mr. Harris's account of the commencement of
the phenomenon, that he observed an arch, at Heron Court,
to be elevated 55° above the northern horizon, at the same
time that I observed one, at Blackheath, to pass over the
planet Mars, then not far from the meridian, and about 46°
above the southern horizon. Mr. Harris observed nothing to
the south of the zenith until some time after the first appear-
ance of the arch : 1 observed no arch towards the north for a
considerable time afterwards ; and as we observed at as nearly
Mi\ Christie on the Luminous Arch of the
as possible the same time, 5h 30ra P. M. in both cases, there
can, I think, be no doubt that our observations were made on
the same luminous band in the same position. Having, through
the kindness of Mr. Faraday, been favoured with Mr. Harris's
interesting observations on the Aurora, I have computed the
height of this arch above the earth's surface, from these ob-
servations and my own ; and although there may be some
doubts with respect to the absolute height, as determined from
these, in consequence of the unfavourable relative positions of
the two places of observation, yet, as the limits which they
determine are very different from the height most recently as-
signed to similar phenomena, I do not hesitate to publish the
results.
Assuming that the arch was formed by a band of light, of
great extent, in a line nearly at right angles to the meridian,
and parallel to the earth's surface, it is evident that, although
different portions of this band were actually observed, the abso-
lute height will be determined from the observed altitudes of
the highest points, and the arc between the parallels to this
band on the earth's surface, in the same manner as if the ob-
servations had been made on the same portion, from places in
a plane at right angles to the arch.
Let then a, £ be the angles of elevation of the same point in
the arch, at two places A arid B, in a vertical plane passing
through that point ; §fte$|-
deration of them will be deferred to a future occasioned* Htiw
C. W.
538 Mr. Scrope on the Ripple-Marks and
ON THE RIPPLE-MARKS AND TRACKS OF CERTAIN
ANIMALS IN THE FOREST MARBLE.
BY G. POULETT SCROPE, ESQ., F.R.S., F.G.S., &c.
HPHE surface of the great elevated oolite range north of Bath
is occupied throughout a very considerable area, by
highly fissile limestone beds, belonging to the forest marble,
and a prolongation of the Stonesfield slate, which are here like-
wise in general use for roofing buildings. Residing in the
centre of this district, I have had frequent opportunities of
observing, in a great number of neighbouring quarries, the ten-
dency of this rock to exhibit a wavy or wrinkled surface, so
completely identical in all its varieties with the rippled mark-
ings of the sea-sands left dry by the ebbing of the tide upon
some of our coasts, as to leave no room for doubting that it
was produced precisely in the same manner, at the period of
the deposition of the beds.
This configuration, though it has not yet perhaps attracted
sufficient attention, (suggesting as it does several very interesting
questions, and tending to confirm many important geological
views,) has been remarked by others as well as myself, and in
other localities. But I have also lately discovered other appear-
ances on the rippled surface of these beds, of a novel character,
to which it may be worth while to call the attention of those
geologists who have time and opportunity for the further ex-
amination of this and similar marine formations.
I have observed the ripple-mark in a vast number of quar-
ries, scattered pretty thickly over a broad band of country,
stretching along the eastern slope of the great oolite range
from Bradford in Wilts, to Tetbwry in Gloucestershire. I have
little doubt that it will be found elsewhere along the continua-
tion of the same beds.
It is repeated throughout a series of strata of considerable
thickness ; and is continuous, not only over slabs of the largest
size which the quarry-men uncover at once, (I have seen one
twenty-five feet long entirely covered with these wrinkles,) but
apparently extends throughout a very much greater area, to be
Tracks of Animals in the Forest Marble. 539
measured, perhaps, in miles ; the corresponding beds in neigh-
bouring quarries being found to have the same configuration.
It is to be seen chiefly in the very fissile laminae, but not
unfrequently on the surface of slabs eight or ten inches in
thickness. It affects indifferently those which contain a large
proportion of clay, those which are highly calcareous and crys-
talline, and others in which sand and oolitic grains, or minute
fragments of shells predominate. The only circumstance, as
it appears to me, which the ripple marked beds possess in
common, is their separation from the neighbouring strata, by
more or less thin seams of clay , moulded on the irregular sur-
face below, and by which the preservation of that surface, in
complete integrity, exactly as it was figured by the waves of
the ocean, at an incalculable distance of time, seems to be
simply and naturally accounted for.
The ripple-marks are always on the upper face of the bed ;
but where the seams of clay are very thin, the alternating
limestone laminae have taken the impression of the uneven
surface on which they were deposited, and thus present an im-
perfect ripple on their lower face also. In this case, however,
the undulations of the upper and lower surfaces do not corre-
spond, but often cross and run counter to one another : occa-
sionally, too, a double system of wrinkles may be seen on the
same surface ; the undulatory movements of the water, by
which they were produced, having shifted their direction (per-
haps through a change of wind) during the period of the de-
position.
I am not acquainted with any published explanation of the
cause of the rippled surface which, at low tide, may be seen
extending over many square miles of sand or mud along the
Devonshire, Lancashire, and many other of our flat and shallow
shores. That it is disturbed and renewed again, partially or
entirely, by every fresh tide, is known to all who have remarked
the constant changes which it undergoes, and the obliteration
of all marks made in the sand at one low tide, before the next
ebb. There can be little doubt that it is produced by the
oscillatory motion of the lower stratum of water in contact with
the sandy or muddy bottom, as communicated to it from the
540 Mr. Scrope on the Ripple-Marks and
superficial waves. It is easily imitated by agitating to and fro
a vessel of water, with a flat bottom, on which sand has been
strewed.
To what depth superficial undulations affect water is a
problem yet unsolved, though the general opinion is, that they
do not ever extend beyond thirty or forty feet. The most vio-
lent movements of the surface water must be neutralized by its
inertia, and their lateral extension as they are propagated
downwards. But they will probably reach considerable depths
before they die away entirely, and will then, I conceive, subside
in precisely the sort of gentle and minute oscillations fitted to
produce the wrinkles in question in mud or sand, either in the
act of subsiding to the bottom, or stirred up there by the com-
mencement or increase of the agitation.
There is an observation which, it strikes me, might perhaps
be applied to determine the depth to which the superficial un-
dulations of water are propagated; namely, by ascertaining
the depth of the water at the spot where the waves, approach-
ing a shore or shoal, begin to swell above their average height in
deep water, and to take the line of direction of the shoal or the
coast, instead of that which the wind impressed them with ori-
ginally. Supposing the British Channel wrinkled by waves
driven before a powerful westerly wind ; these waves, which in
mid-channel have their long axes directed due north and south,
will, as they near the coast on either side, but particularly the
shoaling coasts of Devon and Dorset, gradually take the line of
the shore, upon which each wave breaks at length in a direc-
tion nearly exactly parallel with all its sweeps. This alteration
of their original direction is, no doubt, impressed on them by
their reaction from the bottom, the resistance of which retards
the waves as soon as they come in contact with it, and gra-
dually compels them to assume its sweep. The reaction of
each oscillation from the bottom also causes it to rise by the
rebound higher at the surface, and hence the swell of each
wave as it nears the shore, and its beautiful curve and fall at
last, owing to its superficial movement outstripping that of the
lower part, which is retarded by the friction of the bottom.
A series of careful observations on the depth of the water at
Tracks of Animals in the Forest Marble. 541
which waves of given heights, under similar circumstances of
wind and current, begin to swell and conform to the direction
of the shore, would afford reasonable data for determining the
depths to which the undulatory movement is propagated ; and
I throw out this as a hint to such persons as have the requisite
opportunities for making such observations, and are interested
in solving this question.
A wave is clearly a parcel of water heaped up by the con-
cussion between any external impulse and the resistance of its
own inertia. If the impulse is single, as when a stone is thrown
into still water, the disturbance subsides through a succession
of oscillations, like those of a pendulum, till the equilibrium is
restored. The wave formed in the parcel of water first affected,
as it descends, communicates the impulse laterally to the next
parcel, which consequently rises, and falling again transmits
the impulse to a third, and so on, until the original impulse is
lost by expansion. If the impulse is continued, as by the pro-
longed action of wind on the surface of water, the waves
maintain their full force, or rather increase gradually, so long
as the fresh impulse received during each oscillation is greater
than that lost by lateral or vertical dispersion. Hence, when
a wind begins to act on a calm surface of water, the waves, at
first small, gradually wax higher and broader, and no doubt
progress downwards in the same ratio ; and what sailors call
' a swell ' gets up, after a wind has blown on the sea for a cer-
tain time. This swell continues, owing to the vast momentum
acquired by the agitated waters, long after the wind which pro-
duced it has gone down or shifted, and gradually subsides as it
gradually commenced. It is often vulgarly supposed that
there is a real movement of the water in the direction of the
waves, and indeed the eye has some difficulty in detecting
that this is not the case. On the contrary, waves caused by
wind frequently move with great rapidity in the opposite di-
rection to that in which the body of the water is carried by
tides or currents.
The long axes of waves are of course transverse to the im-
pelling force. In the annexed diagram, each of the waves alter-
nately rises and falls.
542
Mr. Scrope on the Ripple-Marks and
As the wave a falls, and that marked b rises, the particles of
water that lie between a and x (the axis of oscillation) move
laterally towards b ; so that when b is at its utmost elevation,
the particles that were at x are now at b, those that were at 6
at y, &c. , while those that were at a are at x, those that were
at y at a. As 6 falls and a rises, the particles return again,
those that were at b to x, those that were at x moving to a.
Thus there is a continual oscillation of particles of water along
the arcs axb, &c. in the direction of the dotted lines. In the
case of superficial waves, floating objects will appear to vibrate
backwards and forwards between a and x, and x and b. But
these oscillations are not merely superficial : they are propa-
gated to greater or less depths in vertical columns, or rather
wedges, whose axes of vibration are represented by the dotted
lines ex, dy, &c. In the oscillations of the lower stratum of water,
the sand, fuci, or other objects that are held in suspension
near the bottom, or are easily moved along it, will also be seen
to vibrate across the axes of oscillation. The shaded part of
the diagram shews the simplest form of sand-ripple formed by
this vibratory action of the water in contact with the bottom,
the ridges of the wrinkles corresponding to the axes of oscilla-
tion, or intervals between the contiguous oscillations ; there
the water is comparatively still, and the sand consequently
either deposits itself or remains undisturbed, while the inter-
vening hollows are scooped out by the motion of the water.
If the alternate vibrations are not equal in force, but the
movement is more powerful in one direction than in another,
as will be the case with waves breaking on a shore, or those
formed in a stream of running water, the ridge will be pro-
duced on one side of the ripple, that towards which the
strongest oscillations move, as in the diagram below ; so that
each ripple will have one steep and one gentle slope. Where
Tracks of Animals in the Forest Marble. 543
the motion of the water drifts forward the grains of sand, &c.,
as in a flowing tide or a river current, the ripples will advance
by a sort of rolling motion one over the other. These circum-
stances produce the compound forms of ripple-marks, sections
of which are to be seen in the diagrams annexed.
The waves observable on running water are occasioned by
the resistance either of the sides or bottom against which it
impinges, and will be greater in proportion to the roughness of
these resisting surfaces, under similar circumstances of velocity
and volume. The impulse which produces the waves in run-
ning water is its gravity urging it down an inclined plane ; the
elasticity of the fluid causing it, after yielding to this impulse,
to rebound from the bottom or sides against which it strikes ;
and the rebounding wave will be higher and larger in propor-
tion to the force of the impulse. Shallow water, flowing with
a certain velocity, thus moves in a series of bounds or ripples,
whose direction and size are determined by the nature of the
sides and bottom of the stream, and which remain constant in
the same spot as long as these circumstances and the velocity
and volume of the current remains the same.
Thus, in the diagram below, representing a stream of run-
ning water, which, meeting with a large stone «, is flung
upwards in a constant wave c, which is broken at the top if the
obstacle is considerable, and falling downwards excavates a
hollow at 6, immediately behind the obstacle. From thence
the water rebounds upwards in the form of the wave d, which
also usually has a tendency to break, and falling thence, con-
tinues its course in a series of waves, gradually diminishing in
height until the impulse to a vertical oscillation, originally com-
544 Mr. Scrope on the Ripple-Maries and
municated by the resistance a, has exhausted itself. The
points 6, b, in the diagram, are those where the water impinges
on the bottom. The spaces between them, x, x, are compara-
tively at rest, and here, therefore, sand and drift arranges itself,
producing the ridges or ripple-mark observable on the bed of
a stream.
The ripple-mark is not confined to the effects of water, but
is occasionally formed likewise by the wind on the surface of
loose sand, or of drifted snow.
To return to the ripple-beds of forest marble. I had often
admired the sharpness and beauty of their wrinkles, appearing
as if freshly moulded by the receding tide, and carrying the ob-
server back at once to the moment when the sea broke upon the
then narrow shores of this infant island. I had often remarked
upon their surface sinuous traces, like the track of some animal
burrowing in the sand, but failed in satisfying myself to what
they were owing (fig. 1, pi. 5). Having, in the summer of
last year, visited the sandstone quarries of Corncockle Muir, in
Dumfriesshire, where several impressions of the footsteps of
tortoises have been found, it occurred to me to examine mi-
nutely the surfaces of these oolite beds, which, particularly
when rippled, are as smooth and fresh in appearance as when
first formed, and likely therefore to have retained any impres-
sions originally made upon them of similar foot-tracks.
I had not long looked for such before I found a very great
abundance of tracks, certainly not of tortoises, but of some
much smaller animal, traversing the surface of the beds in every
direction ; and some specimens of these tracks, as well as of the
ripple-marks, were lately presented to the Geological Society,
(fig. 2, pi. 5).
It is impossible, I think, to hesitate for one moment in be-
lieving them to be the foot-marks of some small and active
animal moving on the soft surface of the sand and mud imme-
diately after its deposition ; and it is difficult to suppose that
surface not to have been left dry at the time by the receding
tide, since so small an animal as this must have been, could
hardly have had sufficient weight to make such deep marks
below, or at any depth below the surface of the water ; nor is
it easy in that case to believe, that they would, if made, have
Tracks of Animals in the Forest Marble. 545
escaped obliteration. I throw out, merely as a hint, the idea
that the rippled surfaces were left dry and became partially
consolidated under the influence of the air and sun, and that
the seams of clay which cover them were the first deposit of
the rising tide, bearing before it the mud washed into the sea
at low tide from the mouth of some neighbouring river. The
alternate laminae of limestone will, in this case, have been de-
posited during the temporary stillness of the water at high tide.
I shall not make an attempt at determining to what yenus or
even class of animals these tracks are to be referred ; whether
marine, terrestrial) or amphibious. It will be observed, that the
foot-marks vary considerably in size, but are uniformly found
in double lines, parallel to each other, and each shewing two
indentations, as if formed by sharp claws, with occasional traces
of a third claw. In the most perfect specimens (fig. 2, pi. 5)
there is also a third line of tracks, midway between the other
two, as if produced by the tail or the stomach of the animal
touching the ground at each bound ; and where the animal
passed over the sharp ridges of the wrinkles, they are flattened
and brushed down, as if by a moving power of a considerable
force. Thus a ridge between b and d (fig. 2, pi. 5) has been
flattened, and there is a hollow at c, on the steep side of the
ridge, which may have been produced by the animal slipping
down, or climbing up the acclivity.
I leave it entirely to more experienced zoologists than myself
to determine, or even to guess at the animal to which we must
refer these remarkable tracks.
The long and sinuous traces to which I previously referred
(fig. 1, pi. 5) are to me of equally doubtful origin. I should be
inclined to suppose them the produce of some annulose or mol-
luscous animals burrowing in the sand, were it not for their great
analogy to some very slightly different marks in the same beds,
which, from their feathery appendages, seem to be broken por-
tions of the long tentacula of some species of encrinite.
The further examination and comparison of specimens will
probably enable us to clear up these doubtful points.
I shall content myself with remarking on the number of in-
teresting memoranda here brought together, often within the
compass of a single slab, of the remote time when the waves of
546 Mr. Scrope on the Ripple-Marks in the Forest Marble.
the ocean were beating against a line of coast now in the centre
of our island. We see a succession of sedimentary deposits,
consisting of clayey and calcareous mud, wrinkled on the sur-
face by the waves, exactly after the manner of the sandy shores
of our actual coasts; and, like them, having this surface strewed
with small fragments of the shells then existing, of corals,
encrinites, spines of echinus, and Crustacea ; blackened, occa-
sionally, with carbonized vegetable remains, and intersected by
the fresh tracks of some animal which has been actively pur-
suing its prey or disporting upon it. Layer upon layer was
deposited, with these characters, for a considerable thickness,
till a change took place ; not, however, suddenly, but by a
gradual increase in the quantities of sand, clay, or calcareous
matter, till the deposit of the forest marble was succeeded by
the thicker beds of sand and gritstone, of clay, and then of
rubbly limestone or cornbrash.
If the ripple-marks and foot-tracks are allowed to attest the
local coast line of the emerged lands at the date of their forma-
tion, it will become very doubtful whether these beds were ever
in those situations covered by the newer, or, as we call them,
the superior deposits. If they were, there must have occurred
a considerable subsidence in the interval ; but until the ripple-
marks, &c. are found at a great depth below existing marine
strata, it will be allowable to doubt such alternations of sub-
mersion and emersion, and to believe that we have in these
beds the last deposits of the sea in that locality, and that the
coast line since that period has been progressively shifting
eastwards, by the gradual elevation of the island, and the
annexation of new littoral deposits.
At all events, it appears to me, that the further examination
of these marks may prove highly useful, by throwing light on
some of the most interesting, and, at this moment, most agi-
tated questions in geology, namely, the probable outline of the
elevated or emerged lands at the date of the several marine
formations — the problems as to their alternate subsidences
and elevations — and the analogy, in every point of view, of the
oceanic deposits of early date with those which are forming at
present on the existing shores, or at the bottom of the sea.
March 2, 1831,
( 547 )
Proceedings of the Royal Institution of Great Britain.
FRIDAY EVENING MEETINGS, 1831.
Jan. 2Sth. — On the determination of the ages of rocks, of supposed
igneous origin, by Mr. Ainsworth. — Mr. Ainsworth's object was,
by a mineralogical and physical examination of those rocks known
to be of igneous origin, together with the circumstances of associa-
tion in which they are found, and those in which they differ from
neighbouring rocks, to form such associations of indications as
would lead to a comparative estimate of the ages of these rocks,
and in many cases, by consequence, throw light on the rocks with
which they were grouped. His discussions were purely geological,
and he drew for his data from his personal observations of Plutonic
rocks, both at home and abroad, and from the descriptions of others
who have studied this part of science.
Amongst the things on the library tables were a small collection
of minerals from South America, presented by Mr. Bolleart, formerly
chemical assistant in the laboratory. Samples of improved porce-
lain ware, for chemical uses, recently manufactured by Messrs.
Wedgwood, and two large cakes of British silver, from the lead
mines of the Duke of Devonshire, covered upon their upper sur-
faces with those tortuous and tubular configurations which result
from the evolution of oxygen from the metal at the moment of its
solidification. See page 627, ' Miscellaneous Intelligence.'
Feb. 4th. — Mr. Brandeora^e relation of the vegetable, alkalies to
the common alkalies, and to certain proximate principles of vegetables.
— Alter adverting to the generic characters of the alkalies and to
their importance as chemical agents, Mr. Brande proceeded to
remark that, before the discovery of the composition of the fixed
alkalies, various speculations, hypotheses and theories had been
adopted respecting their probable constitution, the most prevalent
being that they contained nitrogen, a notion derived from the exist-
ence of that element in ammonia. Experiments had, however,
actually been made to shew that they were (as was afterwards,
proved) metallic oxides ; and this view of their nature was founded
upon the well-known fact that by far the greater number of the
salifiuble bases, that is, of bodies neutralizing and forming definite
saline compounds with the acids, included a metal and oxygen.
Hence, therefore, analogy had led to a right conclusion, but experi-
ment long failed in its verification ; and had it not been for the
invention and application of a new power, as it were, in chemistry,
we might still have remained ignorant of their real nature. The
knowledge of the nature of the fixed alkalies led, by more successful
548 Proceedings of the
analogy and experiment than the former, to the detection of me-
tallic bases united to oxygen in the alkaline earths, and to the
discovery of the bases of the oilier earths and of boracic acid.
These are happy instances of observation, guided by analogy,
leading to experiment, and analogy verified by experiment, esta-
blishing new scientific truths. The nature of the fixed alkalies
having been thus ascertained, and it having been demonstrated that
they consisted of metals united to oxygen, analogy, emboldened by
previous success, ventured to suggest a similar composition for the
volatile alkali or ammonia: this singular body acts upon vegetable
colours, and neutralizes the acids in the same way as the other alkalies,
but then ammonia had been satisfactorily resolved into hydrogen and
nitrogen ; Us nature, therefore, forms more intricate considerations,
for, if susceptible of metallisation, its metallic bases must, in all
probability, be constituted of those gases or their bases ; and if so,
the nature of hydrogen and of nitrogen would be more or less
included in the discovery, and perhaps even that of the metals
themselves. Such were the analogies that led to the experiment
called the metallisation of ammonia, upon which a theory has been
founded, under the idea that the singular appearances attendant
upon that experiment do really result from the union of metallic
matter with the mercury ; but in the first place, the supposed metal
has never been separated or insulated ; and in the next, there are
strong grounds for believing that the metallisation is a delusion,
and that the effects depend upon a mechanical alteration in the
arrangement of the particles of the mercury, and not upon its com-
bination with an evanescent metal, an opinion strongly corroborated
by Mr. Daniell's experiments, of which he has given an account in
the first number of this Journal.
After shewing the supposed metallisation of ammonia by elec-
trising mercury in contact with its aqueous solution, and by the
action of an alloy of potassium and mercury upon moistened
muriate of ammonia, and comparing these appearances with those
produced by the action of spongy platinum and mercury upon dilute
acetic acid, Mr. Brande made some remarks upon the apparent
necessity of the presence of hydrogen in the production of the
phenomena, and proceeded to observe that, whatever opinion might
be entertained respecting the cause of these appearances, they
had opened an avenue to some new speculations upon the discovery
of these very singular proximate principles in vegetables, which,
under the name of alkalies or alkaloids, constitute a definite series of
salifiable compounds : in regard to these the question had arisen,
what would be the effect of rendering mercury negatively electrical
in contact with them ? The experiments were then shown, of which
an account is given in the last number of the present Journal, alter
which some observations were offered respecting the ultimate con-
stitution of these alkalies, and the analogies which connect them with
other vegetable principles bearing many resemblances to them, but
not salifiable. The existence of nitrogen in the salifiable bases
was especially noticed as a leading1 peculiarity and connecting link
Royal Institution of Great Britain. 549
between them and ammonia; it exists in them in ternary com-
bination with hydrogen and carbon ; oxygen was found in most
of them, but is apparently absent in cinchonia. In consequence,
however, of the imperfection of their ultimate analysis, no general
conclusions could be satisfactorily drawn respecting their atomic
constitution ; some peculiar form, however, of hydrocarbon ap-
peared essential to their saturating power in respect to acids, and
is, perhaps, connected with their high equivalent numbers. The
properties of salicine and of a new crystallisable principle from
elaterium were then shown, and the absence of nitrogen in those
compounds pointed out : its presence was, however, shown in
narcotine and in caffeine, bodies possessing many of the characters
of the former, and yet not salifiable.
A magnificent collection of volcanic specimens, perfect in its
kind, collected from Vesuvius under the superintendence of Monti-
celli, and presented to the Institution by William Pole, Esq.,
M.R.I., was laid upon the library tables.
Several instances of thick-rolled lead, perforated by the larvae of
insects, were also exhibited.
Feb. llth, 1831. — Mr. Harris on the power of various substances
to intercept magnetic action. — The recent discoveries in this depart-
ment of science go far to prove that every known substance is in a
greater or lesser degree open to magnetic excitation ; but it had not
yet been shown that non-ferruginous masses could screen or stop out
the action ; on the contrary, from the few experiments hitherto tried,
it was rather to be inferred that such masses were devoid of this
screening power.* In the course of an extensive inquiry, however,
by Mr. Harris, lately communicated to the Royal Society, it was
observed, that though a single plate of iron of about the tenth of an
inch in thickness, could effectually arrest the action of a revolving
magnet on a disc of copper, yet it had not the same effect on a disc
of iron. In the latter case it was found requisite to multiply the
intervening mass very considerably. Hence, it seemed reasonable
to infer that a screening power might actually be obtained by other
substances not containing iron, but which were susceptible of mag-
netic change, provided such substances were employed in large
masses : such was found to be the case. The apparatus employed
by Mr. Harris, and described by him, consisted of a magnetic disc,
delicately balanced by means of a ring of lead upon a fine centre,
and which was set rotating without sensible vibration, at the rate
of 600 revolutions in a minute, by means of a train of wheels and
a long silk line rapidly run off from its circumference. When the
disc was free of the silk and wheels, it was carefully covered by a
closed cylinder of glass, having aflat surface above and a light disc
of tinned iron moveable on a delicate point placed immediately over
* See the interesting researches of Mr. Herschel, Mr. Babbage, and others,
detailed in the Philosophical Transactions.
VOL. I. MAY, 1831. 2 O
550 Proceedings of the
it; this last was also covered with a glass receiver, and was sus-
tained on a plate of glass at about four inches distant from the
revolving magnet. When the iron began to rotate, a large mass of
copper, of about a foot square, and three inches in thickness, was
interposed ; the copper being placed on a convenient carriage,
moveable on a rail-way, so as to admit of being interposed very easily
without deranging the subject of experiment. The result was, that
the motion of the iron became soon sensibly diminished, and at last
ceased altogether, on withdrawing the intervening copper, the
motion of the iron commenced, and this could be repeated at
pleasure. Similar effects were evident with four heavy masses of zinc
in blocks, each about an inch thick : Mr. Harris had also, he observed,
obtained the same result with a dense mass of silver, of about three
inches thick. He, therefore, concludes that this screening power is
common to every substance in any degree susceptible of magnetic
excitation, and is probably in the direct ratio of its energy, as esti-
mated by observing its influence in fettering the vibrations of an
oscillating magnetic bar. To exemplify a similar screening influ-
ence to that just mentioned, by means of distilled water at 32°
Fahrenheit's scale, or a little below, Mr. Harris believes it would be
requisite to obtain a slight action on the disc of iron at about thirty
feet distance, so as to interpose nearly that thickness of ice. Mr.
Harris accompanied his observations by occasional experimental
illustrations ; he seemed very carefully to distinguish between the
magnetic state, which amounts to a case of permanent polarity, and
that induced or transient state which vanishes when the exciting
cause is removed, to which he considered the immediate effects now
in question might be referred ; for, whilst the intervening mass un-
dergoes magnetic change by induction, it at the same time neutra-
lises, in a greater or lesser degree, the power of the exciting magnet
on a third substance.
In the library, Mr. Harris illustrated, by a few experiments, the
operation of two instruments, which he had recently invented for
investigating the laws of magnetic forces. First, a magnetimeter
for general purposes. A small cylindrical mass of iron, or otherwise
a magnet, is balanced by means of a hydrometric counterpoise
from the horizontal diameter of a delicate wheel, moveable about an
axis on friction wheels. This wheel is furnished with an index
formed of a light straw, duly adjusted, so as to indicate divisions on
a graduated arc, when an attractive or repulsive force is made to
operate on the suspended iron or magnet. By means of a light
frame of brass, and an adjusting screw, a magnet or a mass of iron
can be brought to act under many varying conditions, as to distance,
position, &c. on the suspended body, and the force due to the latter
simultaneously observed. Second, an instrument for measuring
magnetic intensity by means of an oscillating bar. The bar is sus-
pended through a long tube of glass, by means of a filament of silk,
and vibrates under a graduated ring of paper with its poles quite
Royal Institution of Great Britain. 551
free, and without being directly opposed to any substance capable of
acting on it; the extremities of the bar are furnished with two
light indexes of gold wire, which indicate the arc of vibration on
the ring above, and the whole is enclosed in a good pneumatic void,
on a pump plate of fine slate. The entire instrument is made up of
non-metallic bodies, with the exception of the exhausting tubes, and
which are away from the influence of the vibrating magnet. The mag-
netic bar is drawn aside, and liberated at any given angle from its
meridian, by means of a double stop of light brass wire, attached at
right angles to a vertical rod, moveable in an air-tight collar, through
the middle of the pump plate ; and which, being inconsiderable as to
mass near the magnetic centre of the bar, and otherwise at a con-
siderable distance when the bar is set free, do not operate in dis-
turbing the result of the experiment. By means of this double stop,
the bar may be brought completely to a state of rest ; so that when
set free it vibrates steadily and without a swinging motion.
In applying this instrument to determine the magnetic energies
of non-ferruginous bodies, Mr. Harris observed, that it was im-
possible to deduce the comparative values of these energies, from
the mere number of oscillations made in a given arc, under the
influence of these substances, since the result is compounded of
the retarding force of the given body under examination, and that
retarding force by which the bar would be brought to rest, when
oscillating in free space. To get the former force, he divides the
number of oscillations made in a given arc in free space, by the
number of oscillations performed in the same arc, whilst under the
influence of the given substance, and subtracts one from the
quotient, by which he considers that we shall obtain, in every case,
a fair value of the force we seek to determine ; for as the time of
performing a given number of vibrations is not caused to sensibly
vary in this species of action, we cannot resort to the common law
of pendulums, and take the square of the number of oscillations
performed in a given time as a measure of the force.*
There was also on the library table, by Mr. Harris, a beating
* Mr. Harris has deduced his formula in the following mannei : —
Let r =: the retarding force in free space,
R = the retarding force of the given substance,
Then r -f- R will be the whole force in action.
Let a — the number of vibrations in a given arc in free space,
And b =1 the number of vibrations in the same arc whilst under the influ-
ence of the given substance,
Then, since these oscillations may be supposed in the inverse ratio of the
retarding forces — we have
r : r -f R ; : 6 ; a,
Hence ra — 6 (r + R) r= 6 r + 6 R. That is,
ra — b r fa \
•K- T ^ r (-7 1 j but as r is constant in every case,' or
may be taken as unity, we have
a
y — 1 for the value of the force in action.
202
552 Proceedings of the
pendulum, which he proposes to employ in cases where the audible
beat of a pendulum is required for a short time only. This instru-
ment is extremely simple in its construction, and will continue to
beat, after a slight impulse communicated to it, for about ten or
twelve minutes.
Two double-headed planaria from Dr. Johnson ; Mr. Parker's
aero-fountain lamp; finely crystallized glass, &c., &c., &c. were
also upon the table.
Feb. 18th. — Mr. Faraday, on Oxalamede. — It was the object of the
speaker this evening to give an account of that substance, so
curious in a theoretical point of view, discovered by M. Dumas, and
described at page 382 of this volume. The relation of oxalic acid,
ammonia, and oxalamede, to each other, was shown experimentally ;
but as the matter was the same with our former account, that will
suffice for a description of the subject of the evening.
Upon the library tables were placed by Mr. Johnson a very hand-
some chain of palladium, made for the Emperor Nicholas ; a large
piece of native platina, with crystals of the same metal in the hollows
and depressions ; a clock, with a peculiar maintaining power ; a
surveying quadrant by Col. Bainbrigge, so constructed that, by
looking through the centre of the index glass, all parallax was avoided,
and an angle even of 170° readily taken, &c. &c.
February 25th. — Mr. Cowper, on recent improvements in paper-
making. — The improvement of any article in general use is
frequently of more importance than at first sight would appear.
In a low state of civilization men are satisfied with an article so
long as it just answers the purpose, but in a more advanced state
of society improvement gratifies the eye of taste and even in-
fluences the judgment and feelings. With respect to paper,
curious and influential distinctions have arisen in this way, which,
however, sink into insignificance when compared with physical ad-
vantages : as for instance legibility, as in the case of printed books ;
for those that are most legible will be most read. Mr. Babbage
deemed this point of so much importance, that he had his table of
logarithms printed on a variety of tinted paper, to ascertain which
was most legible, most agreeable, or least fatiguing to the eye, and,
as he is an accurate observer, the result is interesting : — Green paper
is the least fatiguing colour, but, by losing its distinctness, required
more effort to read the figures ; while white paper, although more
fatiguing as a colour, renders the printing so distinct, that the eye
catches the figures (or words) with the least effort.
It is economy of production which must introduce an improved
article into general use. It is comparatively of little importance to
have beautiful books unless they are cheap, and this desirable object
has been attained by the improvements in paper-making and printing.
Royal Institution of Great Britain. 553
The process of bleaching; has mainly contributed to the improve-
ment in the quality of paper, while the paper machine, the principal
object this evening-, has secured economy of production.
The machine in general use for making- paper was introduced by
Messrs. Fourdrinier; it was first suggested by M. Didot, (not the
celebrated printer), but his plans were too crude for practice, and
the machine received its perfection from Mr. Donkin. It consists
of an endless web of wove wire, about thirty feet long in the web,
or * wire,' as it is called, and joined together after the manner of
a jack-towel ; the endless wire runs over a number of rollers, placed
horizontally, so as to present a level surface abput fifteen feet long:
as the wire moves, a quantity of pulp is allowed to flow upon it
from a chest, or vat, at one end of the wire ; this chest is furnished
with a broad and level spout extending across the wire ; the spout
has an apron or slip of leather nailed to it, so that the leather
apron lies upon the wire and prevents the pulp from running off,
while the flexibility of the leather allows the wire to move under it
without injury. A shaking or jogging motion is given to one end
of the wire to produce the felting of the floating fibres, and the
water continues to drain from the pulp till it reaches the further
end of the wire : here the water is more completely pressed out by
rollers; the web of paper may then be considered in form; it is,
however, too weak to support its own weight, and is passed over an
endless cloth, in order to expose it to the air, to soak out still more
moisture, and to make the texture firmer by passing it between other
pressing rollers ; it is then passed over large cylinders filled with
steam, which effectually dries it, and the web of paper is finally
wound round a reel, which will thus sometimes contain a single
sheet of paper three-fourths of a mile long.
Beautiful and striking as this machine is, it is yet exceeded by
the machine invented by Mr. Dickinson. Instead of the endless
web of wire thirty feet in length, he employs a perforated brass
cylinder, about twenty inches diameter, covered with the woven
wire. The cylinder revolves in a vat of pulp, in which it is so far
immersed as to leave about one foot4bf the surface of the cylinder
above the surface of the pulp. As the cylinder revolves, the water
flows through the wire into the interior of the cylinder, whence it is
abstracted by a syphon passing through its hollow axis, and the
pulp continues to accumulate upon the whole immersed surface of
the cylinder. At that part of the cylinder which is not immersed in
the pulp, the action of an air pump is most ingeniously applied ;
a pipe from an air pump is introduced through the hollow axis of
the cylinder, and terminates in a pan or trough fitted close by
* packing' to the interior of the unimmersed part of the cylinder; this
air trough maintains its position while the cylinder revolves over it,
and the instant the unformed paper comes over the air-trough, the
water passes through and the paper is set : it is subsequently passed
between pressing rollers, and dried by steam, and reeled up as al-
ready described.
554 Proceedings of the
It has now to be cut into sheets for use. In the ordinary way this
is done by cutting through the reel or coil of paper in the direction
of its axis, then laying- it flat on the table, a block of wood of the
required size is pressed down upon the paper, and a cutting-plough
carried round the edge of (he block. This method occasions a great
loss of shavings, as it is obvious that the outside of the coil must
be larger in circumference than the inside. This loss is now
obviated by a machine invented by Mr. Cowper ; in this machine
the web of paper is cut longitudinally by circular knives, and in a
transverse direction by a serrated knife, resembling a row of pen-
knife points.
Notwithstanding all the care taken to keep little knots and straws
out of the pulp, some will escape, and consequently every sheet has
to pass through the hands of women, who, with a sharp knife,
scratch out any lumps they find 5 but even this defect seems likely to
be removed by the recent invention of Mr. Ibbotson, who has de-
vised a strainer of a peculiar construction, and which is found to
answer. It consists of two brass plates cut into very long angular
teeth, extending across the box or sieve of which they form the
bottom ; when the plates are put together, the teeth of one plate
fills and completely closes the spaces of the other ; on withdrawing
them a little series of long narrow openings or slits are formed.
Now it is found that the fibres of pulp will flow through such
an opening, although they will not flow through small square holes,
while the knots are as effectually stopped by the long slit as they
would be by the square holes.
It is gratifying to observe the extensive results of the im-
provements in paper and printing. Whether we turn to the de-
partments of morals, of sciences, or of the imagination, books are
now published to an extent far greater than at any former period.
An expensive work on political economy never reaches the poor
misguided labourer who destroys machinery ; but when 'The Re-
sults of Machinery ' is published, containing two hundred pages for
one shilling, in three months 25,000 are in the hands of the very
people who ought to have them. Who would not have supposed
that almost all the readers of Sir Walter Scott's admirable tales had
been already supplied ; and yet as soon as a cheap edition is brought
out, the publishers themselves are astonished at the demand, which
obliges them to print more than 1000 volumes every day for three
years, i. e. more than 1,000,000 volumes.
A series of very fine coloured wax anatomical models of healthy
structures, and also of large anatomical drawings and engravings,
were placed upon the tables and appended to the walls of the library,
by Mr. Schloss, of Southampton Buildings.
March bth. — Dr. Edmund Chirke on Vesuvius and Pompeii.—
Dr. Clarke gave an account of the present state of this extraordinary
mountain and town, drawn from his personal observations, and
Royal Institution of Great Britain. • 555
illustrated by numerous drawings, models, and specimens, domestic,
mineralogical, and botanical. He reasoned upon the account of the
eruption of 79 A. D. given by Pliny, explaining some parts and
correcting others, by means of the superior knowledge now pos-
sessed of the history of the mountains, and the natural causes
brought into action by and connected with it.
In the library, amongst many presents, models of useful ap-
paratus, &c. were some Kandyan productions, brought by Captain
Chapman from Ceylon j the most interesting of which were native
drawings relating to the revolt and punishment of Pilime Talarvie
in 1812, and the barbarous treatment of the wife and children of
Ehelypole. It was through the influence of these and similar pic-
torial appeals to the minds of the people, that the island at last
came into the possession of the British.
March llth. — Mr. Aitiger gave an account of the machinery
employed by Mr. Mordan in the manufacture of common pencils,
the leads for the ever-pointed pencils, and the Bramah's pens, the
latter machine being the invention of the late Mr. Bramah. Mr.
Mordan's own machinery, which is of the most beautiful, perfect,
and effective kind, was set up in the lecture-room in working order,
and all the operations of pencil and pen-making performed. Al-
though the beauty and power of the machine could be judged of by
its effects and its principles, and easily understood by the assistance
of verbal explanation, it would be impossible, by writing, to give an
intelligible account, unless it were also a long one, and accompanied
by numerous drawings.
An improved mountain barometer was exhibited in the library by
Mr. Robinson of Devonshire Street, the column of which was di-
visible into two portions when not in use. The fragility of the tube
of a barometer, its inconvenient length, and the necessity of carrying
it in an inverted position, expose it to more frequent accidents than
perhaps any other instrument employed by the scientific traveller.
The objects of this contrivance are to reduce the length of the
barometer, when not in use, to one half of the usual length, and to
render the position in which it is conveyed indifferent, and thus
make it capable of safe and convenient transport. The one portion
of the instrument is a glass tube, of half the length of a barometer
tube— in this tube the mercury is boiled: this tube is cemented into
a steel cistern, the tube projecting into the cistern nearly two-thirds
the length of the cistern ; this part forms, when in use, the upper
portion of the mercurial column. The other portion is a glass
syphon tube ; on the end of the longer leg of which is cemented
a steel screw, which screws into the cistern, forming an air-tight
joint : the cistern is not quite filled with mercury, the air oc-
cupying that space, being the agent employed to cause the
mercury to descend into the syphon. If now the syphon be
screwed to the cistern, and the instrument be put in ah erect
556 Proceedings of the "
position, the air will pass to the upper part of the cistern, and there
its elastic pressure on the surface of the mercury being- the same as
that of the atmosphere in the syphon tube, it will cause the mercury
to descend in that tube; and the length of the mercurial column,
equal in weight to the atmospheric pressure, being thus completed,
the mercury will descend in the upper tube, and rise in the shorter
leg; of the syphon ; if the instrument be inverted, the mercury will
return into the cistern, into which a stopper is screwed when it is
not in use. Each portion of the instrument is enclosed in a brass
tube, with a scale and vernier to read each end of the mercurial
column.
A portable transit instrument, also made by Robinson, was placed
upon the table by Captain Grover.
March 18th. — Mr. Ritchie delivered a lecture this evening; on
elasticity in general, particularly the elasticity of torsion in threads
of glass, with the application of this property to delicate physical
researches. If a portion of air be compressed into a smaller bulk, it
endeavours to regain its former state with a force directly propor-
tional to the force which has been employed to compress it, or
inversely proportional to the bulk into which it has been compressed.
This power, resulting in all probability from the repulsive energy
of the molecules of heat with which it is combined, is termed its elas-
ticity, the only kind of elastic force possessed by aeriform substances.
If a solid body be compressed into a smaller bulk, it also endeavours
to regain its former state with a force proportional to that with which
it was compressed, provided the molecules of the body have not
undergone a permanent displacement. This is called the elasticity
of compression. If a rod or wire be stretched, it will, within certain
limits, also endeavour to regain its former length with a force equal
to that with which it has been stretched, and directly proportional to
the increments of length which it has received. This is called its
elasticity of tension. When a rod is bent, the atoms on one side
have suffered compression, and on the other side extension ; hence
both these forces will act in restoring the rod to its former state, with
a force proportional to the degree of flexure which it has undergone.
If one end of a wire of iron, brass, steel, &c. be fixed, and the other
twisted round, the wire will endeavour to return to its former state
with a force directly proportional to the number of degrees through
which it has been twisted, provided the atoms have not suffered a
permanent displacement; or, in other words, provided the wire has
not taken a set. Coulomb was the first person who investigated
the nature of torsion belonging to metallic wires, and employed
this property in a beautiful manner in his torsion balance. The
celebrated Cavendish also employed it to determine the attraction
of leaden balls, and thence the attraction, and consequently the
specific gravity, of the earth itself; so that, to use the words of a
Royal Institution of Great Britain.
557
French philosopher, he may be said to have weighed the earth in
this delicate balance.
But of all substances glass is the most perfectly elastic, and
from the facility with which it can be drawn into threads of
any degree of fineness, Mr. Ritchie prefers it to wires in all
kinds of torsion balances. He showed the application of this
property to a torsion electrometer, to a magnetometer, galva-
nometer, and torsion balance ; but as the most important of these
applications are already described in the Transactions of the Royal
Society, and at page 29 of the present volume, we shall refer the
reader to these works for more complete information.
Towards the end of the lecture, Mr. Ritchie applied the force of
torsion to demonstrate experimentally the two following propositions :
1st. If a magnetic needle or pendulum be deflected from its
state of rest, the force with which it endeavours to return to its
former position is proportional to the sine of the arc or angle of
deflection.
Let E B F be a vertical cir-
cle, and let C B be a small
wooden pendulum, turning free-
ly on an axis C.
Let one end of a glass thread
six or eight feet long be at-
tached to the axes of the pen-
dulum, and the other end fixed
to a torsion key, as in the tor-
sion balance. Turn round the
key, and observe the degrees
of torsion which the thread has
undergone in raising the pen-
dulum to different heights, and it will be found that these degrees
are directly proportional to the smes of the arcs D K, G B, E B,
through which the pendulum has been raised. If, for example, it
requires 300° of torsion to raise the pendulum through an arc D B
of 30°, it will require 600° of torsion to raise it to 90, or to bring it
to a horizontal position, the sine of 30°, being half the sine of 90°.
The second proposition, to which the property was applied, is
the following: If a pendulum be made to oscillate, the forces which
cause it to oscillate are inversely as the squares of the number of
oscillations performed in the same time. This proposition was
experimentally demonstrated by ascertaining the relative strength
of two threads of glass, and then suspending them from a fixed
point, and attaching a small horizontal pendulum to the lower end,
which was then turned round, and allowed to vibrate by the elastic
force of the glass threads. The squares of the oscillations per-
formed in the same time being inversely as the elastic forces of the
threads employed.
In the library, were a specimen of the platycercus unicula, or
558 Proceedings of the
ground parrot of the Australian islands, from the Zoological Society;
a pump lamp without mechanism ; self-acting syphon ; self- register-
ing thermometer ; and other apparatus by M. Bourdon. Parts of
Mr. Gould's century of birds, with the originals ; casts in bronze,
models in wax of fruit, &c. &c.
March 2bth. — Mr. Faraday on Light and Phosphorescence.—
The object of the speaker was to put before the members an account
of the experiments recently made in the laboratory by Mr. Pearsall,
chemical assistant, on the communication of the power of phos-
phorescence by heat to those bodies which had been deprived of it,
and even to those which had never possessed it. These experi-
ments are already described in this volume, pp. 77, 267 ; but the
results were shown at the evening meeting; and in order that their
bearings on the portion of knowledge regarding light, already in
possession of men of science, might be understood, Mr. Faraday
gave a brief view of the theories of light, and the facts which at
present, imperfectly understood, seemed for that very reason to be
half-opened doors to new knowledge.
On the library-table, amongst other things, were a series of
samples of New Zealand flax (PhormiumTenax) in different stages
of manufacture. It is now worked largely into twine, rope, and
cables, and is exceedingly strong and durable.
The meetings were then adjourned over the 1st and the 8th of
April to the 15th of that mouth.
Proceedings of the Academy of Sciences in Paris.
ASTRONOMICAL SCIENCE, &c.
Aurora Borealis. — THE following observations, communicated by
M. Arago to the Academic des Sciences on the 10th of January,
may be useful in order to determine the real height of the Aurora
Borealis of the 7th of January, by comparing them with the obser-
vations simultaneously made in other places. M. Arago was in-
duced, at an early part of the evening, to anticipate the appearance
of an Aurora Borealis. In his observations on the variations of the
needle, he perceived that, instead of stopping as usual at a quarter
past one, it continued to advance until five in the afternoon. At
this time the declination was 12' 40" greater than usual. The
Aurora was soon visible towards the magnetic north. At ten
minutes past six, the declination had diminished 43' S" since five
o'clock : at a quarter past six, it had diminished 48' 37" ; at eigh-
teen minutes past six, 50' 58". It then began to increase gradually
until a quarter past seven, when it attained its maximum. After a
few moments' repose, the northern point of the needle resumed its
march towards the east; the minimum of its declination was at
Academy of Sciences in Paris. 559
half-past eight. It appears that, by comparing the declination at
this hour with that observed at five o'clock, the horizontal needle
had been affected by the Aurora to the extent of 1° 16' 39". The
instruments with which these observations were made are of such
exactness, as to render it certain that the errors are not more than
five seconds at the utmost. The effect of the Aurora on the needle
of inclination was not less decided ; but the variations of the latter
had no connection with, or analogy to, those of the needle of declina-
tion. Thus sometimes the inclination increased while the declination
diminished; and at others both increased or decreased together;
and several times one of the needles was almost stationary at the
moment of the greatest variations being observed in the other. On
the 7th of January, the least inclination was at ten minutes past
two in the afternoon, and the greatest at thirty-five minutes past
seven. The total variation was twenty-one minutes, while at this
season the diurnal variation scarcely exceeds one minute. At the
moment when the Aurora was at its height, the atmospheric
electrometer of the Observatory did not give the least sign of
electricity.
Tides in the Atmosphere. — At the meeting of the 3 1st of January,
M. Murphy communicated to the Academy a variety of observations
tending to prove that there exists an analogy between the lunar in-
fluence on the tides and the atmospheric temperature. This analogy
is most apparent at the equinoxes and solstices. M. Murphy stated
that during the last winter the lowest degree of temperature, both in
London and Paris, was in each period of frost the day or day but
one after one of the lunar quarters.
BOTANY.
Kelkoa. — On the 31st of January, a report was read to the Aca-
de*mie des Sciences respecting the kelkoa or planera, a tree growing
on the coasts of the Caspian and Black seas. This tree, which was
erroneously distinguished in France by the name of Siberian elm,
received the name of planera from Gmelin, who so called it in
memory of Planer, Professor of Botany at Erfurth. The report
states, that the wood of this tree being hard, elastic, and not easily
injured by damp or worms, may be advantageously used by car-
penters and cabinet-makers ; while the luxuriance of its foliage,
which is not liable to injury from caterpillars, who reject it as food,
renders it a desirable substitute for the elm in avenues. It has also
another advantage over the elm, in not being subject to the cankers
by which the trunk of the latter is so frequently destroyed. Seeds
may readily be procured from Tiflis, or the planera may be grafted
on the elm, which is the easiest mode of propagating it.
Maturation of Fruit. — 21st of February. A report was pre-
sented to the Academy on several memoirs relating to the pheno-
mena observable in the ripening of fruits. Various opinions, in
560 Proceedings of the
some respects contradictory, were given by the different writers,
which it is, therefore, unnecessary to detail. The only certain results
appear to be the following-. In every stage of the progress of the
fruit towards maturity, carbonic acid is constantly produced. The
mode in which this acid is produced is explained in three different
ways by the different writers, all of which, however, are the result
rather of conjecture than of experiment. The progress of the fruit
towards maturity is thus described. First, the sap is converted into
a viscous liquid, (cambium,*) which circulates under the rind.
When this liquid becomes abundant, it allows part of its water to
escape, which evaporates and is converted into gum : it passes
through the peduncle to the ovary, where it forms the pericarpium.
In its course, it modifies itself by appropriating part of the oxygen
of the water of which it is composed, and thence result the various
acids, as citric acid, &c. As the fruit enlarges, the pellicle becoming
thin and transparent allows the light and heat to act with more
effect ; then commence the phenomena of ripening, properly so
called. The acids have a reaction on the cambium which circulates
in the fruit, and, by the aid of heat, transform it into a sweet or
syrupy substance. These acids soon disappear in their turn, being
subjected to a species of saturation by the gelatine. When these
phenomena are accomplished the maturity is perfect. Several of
the experiments made, in order to ascertain the mode in which the
saccharine matter is produced by the reaction of the acids on the
gum or gelatinous part of the fruit, are very curious, and merit par-
ticular attention.
1. If the jelly of apples be acted on by a solution of a vegetable
acid in water, in a short time, (if a proper temperature be preserved,)
a saccharine matter, analogous to that of grapes, is obtained.
2. The gum of peas, placed in the machine autoclavi *, with a
certain quantity of oxalic acid, and in a temperature of 257° F.
is converted into saccharine matter.
3. Ordinary fecula, heated in the same manner, passes first into
a state resembling externally gum arable, but differing from it, inas-
much as when acted on by nitric acid it does not generate mucic acid.
4. If this gum of fecula be added to the juice of unripe grapes,
and heated, the liquor becomes sweet. A similar effect is produced
if, after having saturated it with chalk and filtered it, tartaric acid
be dissolved in it and the solution boiled. We hence see why fruits
become sweeter by dressing, and grape-juice by evaporation, be-
cause part of the jelly is converted into saccharine matter.
Circulation in Plants. — An interesting conversation took place
in the Institute, on the 21st March, between MM. Cassini, Arago,
and Humboldt, on the subject of a letter written to the Academy by
M. Dutrochet, in which he attempted to prove that the supposed
circulation discovered by M. Schultz in the celandine (ficus elastica)
and other plants with milky juice, was a mere optical deception,
occasioned by a trepidation of the molecules, similar to that which
* An improvement of Papin's Digester, j
Academy of Sciences in Paris. 561
is observed in the capillary blood-vessels of dead animals ; this
trepidation of the molecules in the blood-vessels is not perceptible
under a diffused light, hut becomes visible when the vessels are ex-
posed to the action of the direct solar rays. The united testimony,
however, of the three academicians above mentioned was in opposi-
tion to M. Dutrochet's opinion, which they supposed to have origi
nated in his having only tried the experiments with the celandine, in
which the circulation is, in fact, not visible, except with direct light,
whereas, in the ficus elastica, alisma plantago, and others, it is
clearly to be distinguished by diffused light.
This subject was resumed on the 28th of March, when M. Mirbel
read a letter from M. Amici, (well known for his improvements on
the microscope,) detailing some experiments which he had recently
made on the leaves of celandine, and which had induced him to
attribute the movement of the juice, not to a system of circulation,
but merely to the effect of the heat either of the lamp, or even, in
some cases, of the human hand alone. He conceives that the
caloric, acting on the gaseous molecules interspersed among the
solid or liquid molecules, occasions those molecules to dilate and
displace each other, thus forming a constant movement, which,
however real, he does riot admit to be circulation, as it is not de-
pendent on a vital principle ; or he supposes that the heat acts by
means of a thermo-electric current passing through the juices ; or,
thirdly, by means of the air passing from the trachea by the anasto-
mosis existing between the two orders of vessels, and thus impel-
ling the juice before it. But in order to remove any doubt as to the
effect being produced by the heat, and not by the light, M. Amici
subjected the leaves to the action of a hot iron, and perceived, by
the aid of a reflecting mirror, that the heat invariably determined
a motion of the fluid in an opposite direction, changing from left
to right, and vice versa, as the position of the iron was altered.
M. Amici thence concludes that celandine may be made useful as a
thermoscope. M. Mirbel, in remarking on this letter, observed
that, although some doubt may exist as to the reality of the circula-
tion in celandine, there can be none as to the ficus elastica, where
there is evidently not mere trepidation but translation visible by a
diffused light ; and that it is not determined by the influence of
caloric, as supposed by M. Amici with respect to celandine, is evi-
dent from the fact of the liquid passing in circulation under the
point exposed to the action of the direct solar rays, where the heat
is consequently greatest, and where, the action being vertical, the
supposed repellent power of the caloric ought to be neutralized,
and the liquid remain stationary in that point, and to be thence
repelled in opposite directions as from a centre, which is not the
case, the movement being uniformly in the same direction in each
vessel. M. Cassini also remarked that, if M. Amici were right in
his opinion, the phenomenon which he (M. Cassini) had observed
of two vessels containing the juice, and placed close together, ex-
hibiting a circulation in opposite directions, would be impossible.
M. Dutrochet also sent a second letter, in which he stated that he
562 Proceedings of the
had confirmed his opinion of the non-existence of circulation in
celandine, by placing a small quantity of the yellow juice in a glass
tube, taking' care that the space occupied by it not being* beyond
the field of vision of the microscope, he could see both extremities
on exposing this liquid to the action of the direct rays. The ap-
pearance of a rapid current flowing along the tube was produced ;
but the liquid did not, in fact, change its place in the slightest de-
gree. This molecular trepidation was no longer visible when a
diffused light only was employed. It does not, however, appear
that M. Dutrochet has entended his experiments beyond the celan-
dine. It appears, however, certain that the circulation cannot be
asserted to exist in plants with milky juice, (a sue laiteux,) as a
class, but that it is a phenomenon existing partially and arbitrarily,
which must be traced and examined in each individual case.
CHEMISTRY.
New Metal Vanadium. — At the meeting of the Academic des
Sciences, on the 7th February, M. Dulong read a letter from M.
Berzelius, announcing the discovery of a new simple substance by
M. Sefstrom, director of the mines of Fahlun, in Dalecarlia. M.
Sefstrom having occasion to examine an iron remarkable for its
softness, observed the presence of a body which appeared new to
him, and which he succeeded in separating, but in too small a quan-
tity to determine its properties. He afterwards observed that cast-
iron contained much more of it than wrought iron, which induced
him to suppose that he should find still more in the scoria, in which
he was not deceived, as he obtained it in considerable quantities.
It appears to be a new metal, to which he has given provisionally
the name of Vanadium, derived from an ancient deity of the Scan-
dinavians.
At the meeting of the Academy on the 28th February, M. de
Humboldt exhibited a specimen of this new metal. He stated that
the same metal had been discovered in Mexico, by M. del Rio, in a
brown lead ore found in the district of Zimampas. M. del Rio gave
it the name of Erythronium, but was afterwards induced to suppose
that it was not a simple substance, but merely an impure chrome.
Since the discovery of M. Sefstrom, however, the brown lead ore of
Zimampas has been again analysed, and a simple substance, pre-
cisely similar to that found in the iron by M. Sefstrom, obtained
from it. See page 625 of Miscellanea.
Magnesium. — 21st February. A report was made to the Aca-
demy on the mode adopted by M. Bussy, for obtaining magnesium
in a metallic state, which is, by decomposing chloride of magnesium
by means of potassium. Magnesium is a brilliant metal, of a sil-
very whiteness, perfectly ductile and malleable, fusible at a compa-
ratively low temperature, and, like zinc, capable of sublimation at a
temperature very little higher than that of its fusibility, and con-
densing under the form of small globules. It does not decompose
Academy of Sciences in Paris. 563
water at the ordinary temperature ; it oxidises at a high tempera-
ture, and is converted into magnesia; slowly when it is in rather
large pieces, but when it is in fine dust, it burns with great splen-
dour, throwing out sparks like iron in oxygen.
Perchloric acid. — March 14. M. Serullas communicated to the
Academy the result of an experiment which he had just made on
perchloric acid. He stated that he had observed that this acid,
when combined with several of the vegetable alkalies, formed acid
salts in a perfect state of crystallization, which induced him to
endeavour to obtain perchloric acid in a concrete form, in order to
strengthen his theory of the general tendency of concrete acids to
generate acid salts. He had already tried the experiment with
potash, but had obtained only a neutral salt.
He now distilled the perchloric acid with about two or three times
its weight of concentrated sulphuric acid. This, when in a state of
ebullition, occasioned the separation of chlorine, which gave a yellow
colour to the liquid, and at the same time of perchloric acid, which
was received in a tube and surrounded with ice ; part of this acid
was in a liquid, and part in a crystallized. In this state it does not
contain any sulphuric acid, the temperature not being sufficiently
high to admit of its distillation ; when exposed to the air, white and
very thick vapours are emitted ; when poured into water, each drop
produces a sound similar to that of red-hot iron dipped into the
liquid. The solid portion crystallizes in transparent prisms, and
the liquid part, when exposed to the air in a watch-glass, is rapidly
volatilized, acquiring solidity, until it totally disappears. M. Se-
rullas had not ascertained whether it was entirely free from water.
GEOLOGY.
Elevation of the Morea. — In a paper communicated to the
Academic des Sciences, on the 31st January, containing a series
of geological observations made by M. Boblaye, in the Morea and
in Egina, it is stated that there are positive proofs of the whole
soil having risen considerably, not in a gradual or continuous man-
ner, but by sudden starts, so that the grounds abandoned by the
sea are marked out in steps or layers in irregular gradation.
Hwnboldt's Map of Heights. — On the 21st March, M. de Hum-
boldt exhibited to the Academy a map, which he calls • Esquisse
Hypsometrique des rauds des montagnes et des ramifications de la
Cordillere des Andes depuis Cap Horn jusqu'k 1'Isthme de Panama
et a la chaine littorale de Venezuela.' It extends from 62 to 84
degrees of west longitude, (Mer. Paris,) and from 21 degrees south
to 11 north latitude. In a verbal explanation which he gave of it,
he observed that notwithstanding the numerous men of science
who had traversed the Isthmus, no positive information had been
obtained respecting the heights of the mountains which continue
564 Proceedings of the
the chain of the Andes at that spot, until two Colombian engineers,
MM. Lloyd and Falmarck, made a geometrical survey, by order
of General Bolivar. It results from their labours that the chain is
so much lowered here as not to exceed ninety- five toises in height,
which perfectly coincides with the opinion formerly expressed by
M. de Humboldt, that, judging from the vegetable productions on
the summit, the height must be between five and six hundred feet.
M. de Humboldt then entered into an elaborate geological disserta-
tion on the raising of the chain of the Andes, and its ramifications,
and clusters in the form of feeders (filons) ; he described the ridges
or sills which, stretching across plains, unite the apparently insulated
mountains of Lake Parimee with the Andes of Timana, and the
chain of Brazil with the mountains of Cochabambo. The pre-
tended chain of mountains which has been represented as uniting
the Oural and the Altai, in the north of Asia, is in fact only a ridge
serving as a line of division between the waters which fall into the
Obi, and those which flow to the lake Azal.
MEDICAL SCIENCE.
Twisting of the Arteries. — On the 3 1st January, M. Amussat
presented to the Academy four individuals on whom his principle
of twisting (torsion) of the arteries after amputation had been suc-
cessfully tried. In no case had any secondary hemorrhage oc-
curred. He stated the advantages of this system over that of the
ligature to be, that it could be carried into effect by one operator
without assistance, that it is never followed by consecutive
hemorrhages, and allows the immediate re-union of the parts in the
full force of the term. The system has been successfully adopted by
MM. Waust and Anciause, at Liege ; Friecke and Schreuder, at
Hamburgh ; and Dieffembach and Rust, at Berlin.
Lithotrity. — On the 24th January, Dr. Civiale communicated to
the Academy a report of the cases oflithotrity recently placed under
his observation. He attributes the failure of the process, in most
cases in which failure has occurred, to the imperfection of the in-
strument employed. By his method of treatment he state that
lithotrity has been successfully resorted to in 163 cases, 152 of
which were operated on by himself.
Galvanic Application. — On the 7th February, Dr. Andrieux
announced to the Academy that he had invented an apparatus, by
means of which the action of galvanism on patients can be so
graduated as to allow it to be applied daily either in the same de-
gree or with a gradual increase of intensity. He attributes the
small advantages hitherto derived from the application of galvanism
in medicine, to the fact of the apparatus not having been so disposed
as to allow of comparative results being obtained.
Academy of Science in Paris. 565
New Remedy. — At the same meeting, M. Jumeret Perrault, of
Neufchatel, announced that he had discovered in the mountains a
plant which affords a sovereign remedy in phthisical and pulmonary
complaints. He offers to supply it at fifteen sous (sevenpence half,
penny) per pacquet. From the description it appears to be a species
of asplenium.
Action of Oil of Turpentine, Opium, fyc. on the Nervous System.
— At the same meeting M. Flourens detailed the results of a series
of experiments which he had made on the action of the essential oil
of turpentine, opium, and alcohol, when applied to different
parts of the brain. The operation was performed on rabbits, the
cranium and dura mater having been previously removed; in all the
experiments he took care to renew the substances as soon as they
disappeared from the surface of the organ by absorption or evapora-
tion. The oil of turpentine applied to the lobes of the brain, in a
certain time produced an agitation, with occasional intervals of re-
pose. Sometimes the animal leaped forward, and at others turned
round in a spiral direction. During the paroxysms the animal ap-
peared in a state of furious madness, and neither saw nor heard,
but in the intervals of repose the faculties of sight and hearing ap-
peared uninjured. On applying the oil of turpentine to the cere-
bellum, a strong tendency to run and leap was observed. The ef-
fects of alcohol were similar, but less violent, never producing the
circumgyration. Liquid opium applied to the lobes of the brain in
a very short time produced an insensibility or torpor, which continued
even when the animal was pinched. A tension of the anterior limbs
sometimes occurred to such a degree as to push the body back, so
as to turn it over on its back. Opium, when applied to the cere-
bellum, produced an overthrow of the equilibrium, so that the
animal could only move by dragging itself along on its abdomen.
Having remarked that the involuntary movement produced by the
oil of turpentine tended to carry the animal forward, while that
produced by the opium carried it backwards, M. Flourens applied
both together, and found that, to a certain extent, these contrary ef-
fects neutralized each other. The effects produced by the opium
appeared to resemble those produced by the successive removal of
different parts of the brain, while those of the oil of turpentine and
alcohol were analogous to what might be supposed to result from
an over repletion (hypertrophe) of the different parts of the brain.
Acupuncturation of the Arteries. — At the meeting of the 14th of
February, M. Velpeau suggested the acupuncture of arteries as a
means which might generally be advantageously substituted for
ligature.
Affections of the Vocal Organs.— On the 7th of March M.
Majendie made a very favourable report on a memoir presented by
VOL. I. MAY, 1831. 2 P
566 Proceedings of the
Dr. Bennati, physician to the Italian Opera, on the diseases of the
uvula to which singers, orators, and others accustomed to great
exertion of the vocal organs, are suhject. Dr. Bennati details a
number of instances in his own experience which prove the inexpe-
diency of excision in cases of relaxation or prolongation of the uvula,
and recommends cauterisation with nitrate of silver as an almost
infallible remedy. The doctor has also invented a new species of
portocaustique, by means of which the front, back, and lower parts
of the uvula are at once subjected to the action of the caustic.
Application of Galvanism. — At the same meeting a very elabo-
rate paper on the application of galvanism to medicine was read by
Dr. Fabre Palaprat. He details a number of experiments tending
to prove the analogy, if not identity, of the electric with the vital
principle. The result of his observations is, that galvanism may be
usefully employed as a medical agent in the following diseases :
nervous affections in general ; chronic diseases of the abdominal
organs, when not resulting from an organic injury ; hypochondria,
nervous asthma, head-ache, and some cases of paralysis. M.
Fabrd Palaprat also states that he had found the union of acupunc-
ture with galvanisation highly advantageous in producing slight
instantaneous irritations of the skin, and also for introducing
various medicaments deep into the body, by means of the acupunc-
tural conductors acted on by galvanism.
Use of Salicine. — March 14th, two instances of the successful
application of salicine or willow-bark in cases of intermittent fever,
were communicated to the Academy by Dr. Ferrand de Missol.
The first was that of an infant of twenty-five months old, who was
suffering from odaxistique, or teething fever. Eight grains of
salicine were administered in two doses: after the first, the child,
who for many days had refused nourishment, showed a disposition
for food ; two days afterwards twelve grains were given in three
doses, and afterwards continued for four days in doses of one grain
each. At the end of that time the child was perfectly recovered.
This case gives the doctor occasion to remark, that where the fever
is essentially odaxistique, the character and symptoms which consti-
tute it are principally nervous. The second case was that of a
young man, aged seventeen, suffering under a strong intermittent
fever: an emetic was first administered, which relieved the pains in
the stomach and head, but did not otherwise diminish the fever ;
five days afterwards twelve grains of salicine were administered,
the shiverings ceased, but there was a paroxysm of fever at six
o'clock ; the next day eighteen grains were given, the paroxysm
was at seven; for six days the dose was gradually increased to
forty grains, and every day the paroxysm took place at longer inter-
vals ; on the seventh day there was none, the dose was then dimi-
Academy of Science in Paris. 567
nished to twenty grains ; and in three days more the patient was
cured.
Cholera Morbus. — An incalculable number of letters, memoirs,
and documents of every description, have been piled on the table of
the Academy relative to the cholera morbus ; but as they generally
consist of speculative theories, and merely controversial discussions,
it would be idle to lay them before our readers. An exception,
however, to this rule exists in a paper forwarded by Dr. Jahinichen,
who, as a member of the council appointed to examine the progress
of the disease, had personally observed the majority of cases in
Moscow, and whose talent renders his opinions valuable. The
conclusions at which he has arrived are the following: — 1. The
cholera morbus is not a pestilential disease. 2. It is not either
directly or indirectly contagious. 3. A germ or miasma of cholera
emanating from the diseased person exists in the atmosphere sur-
rounding him. 4. These emanations may be sufficient to originate
disease, even when only proceeding from a single person, if the
malady be violent, but will always be so in a hospital. 5. But a
particular predisposition (arising generally from the greater or less
irregularity in the mode of living) is necessary in each individual,
to produce the developement of this miasma of cholera. The pro-
portion in which this predisposition exists in a population has not
been ascertained with sufficient certainty to establish a general
rule ; at Moscow it was about three in every hundred. 6. The
propagation of the cholera is in accordance with the usual laws of
epidemic diseases. 7. There is every reason to believe that pulmo-
nary absorption is the only method by which the miasma is intro-
duced into the human body. There is, therefore, no contagion, in
the sirict meaning of the word, but rather a species of penetration.
8. The miasma appears to have a peculiar affinity with the aque-
ous vapours in the atmosphere, and to be equally volatile. Dr.
Jahinichen then adds, that he obtained, from the condensation of
these vapours in rooms containing a number of patients, a sub-
stance entirely resembling that obtained by Moscati at Florence,
and suggests that a close observation of the hygrometrical and
barometrical variations of the atmosphere may throw light on the
geographical march of the disease. He also thinks it probable that
the miasma inherent in the aqueous vapours may rise in the atmo-
sphere, and, being transported by a current of air to other countries,
be inhaled by the inhabitants of those countries, and thus originate
the disease. Should this conjecture be well founded, all quarantine
and other precautionary measures must be useless, unless respira-
tion could be suspended ; and there is reason to fear that the
ravages of the disorder in the western parts of Europe may be
more extensive than in Russia, in consequence of the prejudices
existing against hospitals, which, by keeping the patient at home,
will render each house a separate source from which the fatal
2P2
568 Proceedings of the
miasma may emanate. We should mention that these opinions of
Dr. Jahinichen have been warmly attacked by M. Moreau de Johnes,
and other advocates of the contagious properties of the disease, but
their arguments are rather theoretical than founded on specific facts.
NATURAL PHILOSOPHY.
Electrical relations of bodies to heat. — At the meeting of the
Acad6mie des Sciences, held on the 17th of January, M. Becqueril
read a memoir entitled * Theoretical considerations on the changes
operated in the electrical state of bodies, by the action of heat, con-
tact, friction, and different chemical actions, and on the modifica-
tions which are occasionally produced in the arrangement of the
constituent parts of those bodies.' The object of this memoir is to
explain some of the causes which in process of time effect a change
in many of the substances forming, the superficial stratum of the
globe. After referring to Laplace's theory of the igneous origin of
the earth, he observes, that the diminution of the temperature must
have successively produced great change in the combination of the
elements of which the bulk of the earth is composed, in the con-
stitution and pressure of the atmosphere, &c. He proposes to trace
the origin of all these phenomena, and to investigate their causes
and physical laws, and commences by some general considerations
on certain properties of matter ? after which he examines the effects
of heat on the electric fluid of metallic substances considered sepa-
rately and in contact, and the state of the atoms in the various
combinations. By means of a very simple apparatus, he demon-
strates that heat does not possess any influence over free elec-
tricity; but on the contrary acts very decidedly on the natural
fluid. He has observed, that, the heat which separates the mole-
cules of bodies, produces on the natural fluid an effect analogous
to that obtained by the cleavage of regularly crystallized substances,
viz. the diminution of the reciprocal action of the two electricities.
He then enumerates a variety of experiments, which authorize the
conclusion, that the two electricities are raised by heat to a higher
degree in bodies which are negatively than in those which are
positively electric. This fact explains the reason of the oxides of
the negatively electric metals being more easily decomposed by heat
than those of other metals. He then, after having given a detailed
account of the various phenomena relating to the influence of heat
in exciting the electric power in metals, enters into the question of
the development of electricity by contact. Volta, in attacking
Galvani's theory on muscular contractions, conceived the idea that
they were owing to the electricity emanating from the contact of
two heterogeneous substances : according to his theory, two sub-
stances always become in a state of contrary electricity by mutual
contact, leaving out of consideration any modifications produced on
the surfaces in contact. M. Becqueril then noticed the theory,
Academy of Science in Paris, 569
advanced by M. Delarive in opposition to Volta, that the action of
the contact was only the result of the difference of the chemical
actions of the air and water, and of external agents, on each of the
two bodies; and stated, that though he had at first been staggered
by it, the consideration that the electric fluid acts as a moving
power in producing combinations induced him to retain his original
opinion. In order to show the nature of this action in its full extent,
he pursued his experiments on mineral substances which are electric
conductors, and so little susceptible of atmospheric action, that their
constitution sustained no change from being exposed for ages to
the inclemency of the seasons. He details his experiments on
platina, peroxide of manganese, magnetic oxides of iron, and gold ;
from which it appeared that the peroxide of manganese was, as
might be expected from its high degree of oxydisation, negative in
its contact with all the other bodies. He next examines the causes
of the thermo-electric action in closed circles composed either of
one or of two different metals, and states, from all his experiments
it appears that these phenomena are owing to the difference of the
thermo-electric powers of the metals. From some observations
made on the relation between the thermo-electric faculties, and the
capacity for heat in various metals, it appears that those metals
which are most negatively electric have the least specific heat.
The memoir concludes with an expose of the electric properties of
atoms. M. Becqueril examines the theory of M. Ampere, and also
that of M. Begneul, who, from the experiments he had made, con-
cluded that the atoms in combination were merely small electric
piles, the reciprocal and continuous action of which constitute what
we call molecular attraction ; but M. Becqueril considers the
question, whether the action of particles of bodies on each other is
entirely produced by electric action or by some unknown power, as
still undecided.
ZOOLOGY.
Sturgeon.— On the 24th January M. Cuvier made a very fa-
vourable report to the Academy on a work by Messrs. Brandt and
Ratzeburg, of Berlin, entitled the Monography of Sturgeon, in which
the genus is divided into fourteen species, which are described with
great minuteness, and in a manner calculated to be of great ad-
vantage to zoologists.
Teleo-saurus. — On the 21st February M. Geoffroy de St. Hilaire
presented his two memoirs on the animal, the fossil remains of which
were discovered in Normandy in the years 1828, 1829, and 1830,
which has been erroneously designated as the fossil crocodile of Caen.
He now names it the genus teko-saurus. These memoirs describe,
at great length, the difference between this animal arid the crocodile :
the scales have no centre ridge, but are placed one over the other
like those of fish, whence it is supposed that this animal was more
570 Proceedings of the Academy of Science in Paris.
essentially aquatic than the crocodile. The whole of the animal
has been now found, with the exception of the anterior feet and
part of the posterior feet. The whole plastron of the back of the
teleo-saurus is not composed as in the crocodile of several rows of
plates careened to the centre, but of two rows only of plates without
apparent projecture, the outward part thin, and the inner, by which
they are strongly united together, very thick; they cover each other
behind like the scales of fish. The fore part of the tail is also
covered with two rows of scales only, but these present a longitu-
dinal ridge towards the outward part, which forms two projecting
lines, which gradually approach each other towards the hinder part.
The back part of the tail, which answers to the crest (crete en scie)
of the crocodile, has but one row of orbicular plates, which are
strongly careened at the centre. The lower plastron exhibits
six transverse rows of scales, which are not flexible like those
of the crocodile's belly, but all strong and solid, whence the whole
plastron could only be moved in one piece. Thus, in the general
movements for the purpose of introducing the air into the lungs,
the action of the two plastrons is similar to that of the two parts of
a bellows. M. de St. Hilaire stated, that from the fact of the
posterior aperture of the nostrils being situated at the middle part
of the cranium, he had been induced to imagine that the mode of
respiration of this animal must have been more nearly allied to that
of the tortoise than of the crocodile — a supposition which is fully
confirmed by the construction of the plastrons. It appears (in
confirmation of the aquatic nature of the teleo-saurus) that its
posterior members must have been at least double the size of the
anterior, resembling the kangaroo in its mal-adaptation for walking ;
while the manner in which its whole body was closely covered with
scales prevented its having the agility in leaping of that animal,
so that it was only adapted for the water.
Two-head Lizard. — At the meeting of the Academy of the 28th
February, M. Beltrami announced, that in a recent excursion over
the Pyrenees, he found a two-headed lizard, with five paws, four of
which were naturally formed, but the fifth, which was placed between
the two heads, had nine toes. M. Beltrami promised to furnish
the Academy, on a future occasion, with a minute account of the
habits and mode of life of this animal.
C 571 )
ANALYSIS OP BOOKS, AND SELECTIONS FROM THE
TRANSACTIONS OF SCIENTIFIC SOCIETIES.
The Life of Sir Humphry Davy, Bart., LL.D., late President of
the Royal Society, Sfc. fyc. fyc. By John Ayrton Paris, M.D.,
F.R.S., &c. &c. 4to. London, 1831.
(Concluded from p. 360.)
TN the year 1808, MM. Gay-Lussac and Thenard succeeded in
decomposing potash by chemical means ; and Davy soon repeated
their experiment. This process afforded the means of procuring
potassium more readily in larger quantities than by means of voltaic
electricity. The facility of the combustion of the alkalies, and the
readiness with which they decomposed water, offered Davy the
ready means for determining the proportions of their constituent
parts : he thought potash composed of about six parts base and one
of oxygen ; and soda, as consisting of seven parts base and two of
oxygen. The over-excitement and fatigue of his researches upon
this occasion, and the irregularity of his habits, threw him into a
fever. Such was the alarming state of his disorder, that for many
weeks his physicians visited him four times a-day.
The course of lectures on Electro-Chemical Science, which
he gave on his recovery, commenced in March, 1808, and the
theatre of the Institution overflowed with admiring and interested
auditors. At the same period he gave a course in the evening
on Geology, which was equally attractive. Having succeeded in
decomposing the alkalies, it was natural that he should turn his
attention to the earths; he, however, found them much more
difficult to conquer. While busily engaged in pursuit of his object,
he received a letter from Professor Berzelius, of Stockholm,
announcing that, in conjunction with Dr. Pontin, he had succeeded
in decomposing baryta and lime by negatively electrising mercury
in contact with them, and by such means had actually obtained
amalgams of these earths. Davy immediately repeated the experi-
ments with success; and having, by additional experiments, fully
established the nature of these bodies and the analogies he had
anticipated, he published the result in a memoir to the Royal
Society in June, 1808, entitled — 4 Electro-Chemical Researches on
the Decomposition of the Earths ; with Observations on the Metals
obtained from them, and on the Amalgam of Ammonia.'
It has, however, been doubted whether the change, which am-
monia and mercury undergo by voltaic action, merits the name of
amalgamation, and whether it may not be referred to a purely me-
chanical cause ; and Dr. Paris observes, in a note, that this opinion
is strongly confirmed by Mr. Daniell's paper * On certain Pheno-
mena resulting from the action of Mercury upon different Metals/
published in the first number of this Journal.
572 Analysis of Books, fyc.
His third Bakerian Lecture was read before the Royal Society
in December, 1808 : it contained his * Researches on the nature of
certain Bodies, particularly the Alkalies, Phosphorus, Sulphur,
Carbonaceous Matter, and the Acids hitherto undecompounded;
with some observations on Chemical Theory.' These inquiries are
continued and extended in a paper read before the Royal Society in
February, 1809, and in his fourth Bakerian Lecture, published in
that year. The contents of these papers will hardly admit of
analysis or abridgment, but Dr. Paris has given an account of the
general results : these consist of his account of the mutual action of
potassium and ammonia upon each other; in the course of which he
obtained an olive-coloured substance, which he was inclined to
regard as the metallic base of ammonia : he also believed that
nitrogen had been decomposed during the process, and that its
elements were oxygen and a metallic base, or oxygen and hydrogen.
His attention was called to tellurium by an observation of Ritter,
that, of all the metallic substances, it was the only one by which he
could not procure potassium through the agency of negative
electricity. In pursuing the inquiry, Davy found that tellurium and
hydrogen were capable of combining and of forming a gas, to
which he gave the name of 'telluretted hydrogen; and that so far from
preventing the decomposition of potash, it formed an alloy with
potassium when negatively electrified upon the alkali, and had the
most intense affinity with it. The results of his inquiry whether
sulphur, carbon and phosphorus in their ordinary form may not
contain hydrogen, were far from conclusive. He succeeded in
decomposing boracic acid, but was anticipated in some of his
results by Gay-Lussae and Thenard. He at first proposed to call
the base of that acid boracium ; but, finding it more analogous to
carbon than any other substance, he adopted the term boron. ' His
experiments and reasonings upon muriatic acid, at this period
(says Dr. Paris), derive their greatest interest from their fallacy, and
the vigour he subsequently displayed in disentangling himself from
a web of his own fabrication.'
At this period, on his representation, a splendid voltaic battery
was constructed, the means being raised by a subscription among
the members of the Royal Institution for the purpose. It consisted
of 200 troughs, each containing 10 double plates, arranged in cells
of porcelain, and containing, in the whole, a surface of metal of
128,000 square inches. All the phenomena of chemical decomposi-
tion were produced with intense rapidity by this combination; and
he instituted several experiments with the hope, already alluded to,
of decomposing nitrogen.
The evidence by which Davy established the important fact that
oxymuriatic acid is a simple body, which becomes muriatic acid by
its union with hydrogen, was deduced from a course of experiments
conducted with the most consummate skill and perseverance; the
results of which were given to the world in his Bakerian Lectures
Life of Sir Humphry Davy. 573
for 1809 and 1810, and in a subsequent memoir read in February,
1811. Dr. Paris thinks that, after his discoveries in voltaic elec-
tricity, these are by far the most important of his labours. When
this fact was established,
' it became necessary to alter the nomenclature, since to call a body,
which neither contains oxygen nor muriatic acid, by a term which
denotes the presence of both, is contrary to those very principles which
first suggested it. Having consulted some of the most eminent philo-
sophers, Davy proposed a name, founded upon one of the most obvious
and characteristic properties of the oxy muriatic acid, namely, its colour,
and called it CHLORINE.' — * In the memoir abovementioned, which was
entitled, " On a Combination of Oxymuriatic Gas and Oxygen Gas," he
announced the existence of a protoxide of chlorine, under the name of
euchlorine; and in a communication from Rome, in 1815, he described
another compound of chlorine and oxygen, containing a still larger pro-
portion of the latter, and which has since been made the subject of a
series of experiments by Count Stadion, of Vienna. As it does not ex-
hibit any acid properties, Dr. Henry proposes to call, it a peroxide, in
preference to deutoxide. Its discovery was made during an examination
of the action of acids on the hyper-oxymuriates of Chenevix, undertaken
by Davy, in consequence of a statement of M. Gay-Lussac, that a pecu-
liar acid, which he called chloric acid, might be procured from the
hyper-oxymuriate of baryta by sulphuric acid.'
The chloridic theory may now be considered as fully established :
the philosophers, who were so long hostile to its reception, have at
length yielded their assent; and the subsequent discovery of iodine
and bromine has confirmed, by beautiful analogies, the views Davy
so satisfactorily explained by experiment.
Dr. Paris has asserted Davy's claim to the establishment of this
theory, against the claims of priority set up in favour of the French
chemists.
In November, 1810, Davy delivered a course of lectures to the
Dublin Society, at their invitation, for which he received 500
guineas; and two distinct courses in 1811, on Electro-Chemistry
and Geology, for which he received 750/. ; and before he quitted
Dublin, at his second visit, the Provost and Fellows of Trinity
College conferred on him the honorary degree of LL.D. In the
month of August, 1811, he was requested by a committee to suggest
a method to be adopted for ventilating the House of Lords ; but his
plan appears to have failed, which was a source of vexation to him
and of pleasant raillery to others.
On the 8th of April, 1812, he received the honour of knighthood
from his late Majesty (then Regent), being the first person on whom,
as Regent, he had conferred that distinction ; and on the following
day, he delivered his farewell lecture in the Theatre of the Rojal
Institution.
On the llth of April, 1812, he married Mrs. Apreece, a lady of
very considerable fortune.
The first part of * The Elements of Chemical Science,' a work
which he had been some time preparing, was published in June,
574 Analysis of Books, fyc.
1812. It is dedicated to Lady Davy, to whom he offers it ' as a
pledge that he shall continue to pursue science with unabated
ardour.' Upon this work Dr. Paris has offered some remarks, for
which we regret we have not space. He observes that —
'Although it bears the title of " Elements," its plan and execution are
rather adapted to the adept than the tyro in science ; and though it
has not perhaps announced any discoveries which had not been pre-
viously communicated to the Royal Society, it has brought together his
original results, and arranged them in one simple digested plan — it has
given coherence to disjointed facts, and has exhibited their mutual bear-
ings upon each other, and their general relations to previously established
truths. Very shortly after the publication, it was asserted that the work
could never be completed upon the plan on which it had commenced,
which was little less than a system of chemistry, in which all the facts
were to be verified by the author ; an undertaking too gigantic for the
most intrepid and laborious experimentalist to accomplish. There was
too much truth in the remark — the life of the author has closed — the
work remains unfinished.1
The volume extends only to the general laws of chemical
Changes, and to the primary combinations of undecompounded
bodies.
In October, 1812, he received a letter from M. Ampere, informing
him that a compound of chlorine and azote had been discovered at
Paris, a fluid which exploded by the heat of the hand ; and that the
discovery had cost the author an eye and a finger. M. Ampere
gave him no details as to the mode of combining them, but his own
sagacity led him to the course to be pursued, and Mr. Children
having suggested to him that Mr. James Burton, on exposing
chlorine to a solution of nitrate of ammonia, had observed the
formation of a yellow oil, which he had not been able to collect,
Davy availed himself of the hint, and obtained the fluid in question.
On exposing it to heat, the tube was shivered to atoms by its explo-
sion, and he received a wound in the transparent cornea of the eye,
which was followed by inflammation, and disabled him from pursuing
his inquiry. In the following July, he was again wounded in the head
and hands in attempting its analysis by the action of mercury, but
having taken the precaution of defending his face by a plate of glass
attached to a proper cap, no serious consequence ensued. By using
smaller quantities, and recently distilled mercury, he succeeded
in obtaining results without any violent action : the mercury united
with the chlorine, and azote was disengaged, from which he was
enabled to conclude that it was composed of four volumes of chlo-
rine and one volume of azote. He suggested the name of azotane;
but his nomenclature of the compounds of chlorine not having been
adopted, the substance is denominated chloride of nitrogen. The
results of these experiments were communicated to the Royal
Society in two successive papers. In another paper, read July 8,
1813, he establishes, by satisfactory experiments, that the base of
fluoric acid is a highly energetic body, not hitherto obtained in an
Life of Sir Humphry Davy. 675
insulated form; the properties of which are yet unknown: it
appears to belong to the class of negative electrics, and to have a
powerful affinity for hydrogen and metallic substances. Though this
theory was his own suggestion, he acknowledges that we are
indebted to M. Ampere for establishing it.
It has been stated that he gave his last public lecture in the
Royal Institution in April, 1812 ; he, however, afterwards delivered
an occasional lecture to the managers on his own discoveries, and
did not formally resign his professorship until the year 1813.
* At a general monthly meeting of the members, April 5, 1813, the
Earl of Winchilsea in the chair, Sir Humphry Davy rose and begged
leave to resign his situation of Professor of Chemistry ; but he by no
means wished to give up his connexion with the Royal Institution, as he
should ever be happy to communicate his researches, in the first instance,
to the Institution, in the manner he did in the presence of the members
last Wednesday, and to do all in his power topromote the interests and
success of the Institution.'
On the motion of Earl Spencer, thanks for his inestimable
services were voted to him unanimously, and he was elected
Honorary Professor of Chemistry, being succeeded as Professor by
Mr. Brande. In March of this year, he published his ' Elements of
Agricultural Chemistry.' Of this valuable work Dr. Paris has
given a complete review, well warranted by the importance of the
subject.
Mr. Faraday has furnished to Dr. Paris a relation of the circum-
stances which attended his introduction to Sir Humphry Davy,
which, as they cannot fail to be interesting to readers of this
Journal, we shall briefly narrate. ' Bergman (says Dr. Paris)
considered the greatest of his discoveries to have been the discovery
of Scheele;' and among the numerous services rendered to science
by Davy, the amiable conduct which led to the placing Mr. Faraday
in the Royal Institution, and thus giving to the world ' a philosopher
capable of pursuing that brilliant path of inquiry which his master's
genius had so successfully explored,' is not the least estimable ; and
to use the words of his grateful pupil, ' bears testimony to his
goodness of heart/ Mr. Faraday's account is as follows : —
' When I was a bookseller's apprentice, I was very fond of experi-
ment, and very averse to trade. It happened that a gentleman, a mem-
ber of the Royal Institution, took me to hear some of Sir H. Davy's last
lectures in Albemarle-street. I took notes, and afterwards wrote them
out more fairly in a quarto volume. My desire to escape from trade,
which I thought vicious and selfish, and to enter into the service oif
science, which I imagined made its pursuers amiable and liberal,
induced me at last to take the bold and simple step of writing to Sir H.
Davy, expressing my wishes, and a hope that if an opportunity came in
his way, he would favour my views ; at the same time I sent the notes
I had taken at his lectures.'
Davy's answer was kind and encouraging; and shortly after the
situation of assistant in the Laboratory of the Royal Institution
becoming vacant, he recommended Mr. Faraday. —
576 Analysis of Books, fyc.
* At the same time that he thus gratified my desires (continues Mr.
Faraday) as to scientific employment, he still advised me not to give up
the prospects I had before me ; telling me that science was a harsh
mistress, and, in a pecuniary point of view, poorly rewarding those who
devoted themselves to her service. He smiled at my notion of the supe-
rior moral feelings of philosophic men, and said he would leave me to
the experience of a few years to set me right on that matter.'
Mr. Faraday entered upon his appointment in March, 1813, and in
October of the same year, accompanied Sir II. Davy in his con-
tinental tour, as his secretary and experimental assistant. Napo-
leon, who had sternly refused his passport to several English
noblemen, with a liberality worthy of his character as a patron of
science, allowed Sir H. Davy to travel through France; his purpose
was to visit the extinct volcanoes in Auvergne, and to examine that
which was still in activity at Naples. Dr. Paris has given an
interesting account of the occurrences in this tour, principally
supplied from the journal of Mr. Faraday and the communications
of Mr. Underwood, who, though a detenu, had, during the whole
war, enjoyed the indulgence of residing in Paris. This gentleman
acted there as cicerone to his distinguished friend, and Lady Davy,
who accompanied him in his tour.
4 Nothing could exceed the liberality, unaffected kindness, and atten-
tion with which the savans of France received the English philosopher.
Their conduct was the triumph of science over national animosity.'
An unknown substance having been accidentally discovered by a
manufacturer of saltpetre at Paris, but kept secret by him several
years, he at length communicated it to M. Clement, who had found
that it might be resolved into a violet-coloured vapour. M. Ampere,
having received some of it from M. Clement, transferred it into the
hands of Davy. This unknown substance, which had been desig-
nated X, was iodine. The first opinion of the French chemists was,
that it was either a compound of muriatic acid or of chlorine. The
first public notice of its existence was given by Clement at the
Institute, on the 29th of November, 1813 ; and at the meeting of the
6th of December, Gay-Lussac, who had only received some X a few
days previous, presented a short note, in which he gave the name of
iode to the body, and threw out a hint as to its great analogy to
chlorine, at the same time stating that it might be considered as a
simple substance, or as a compound of oxygen. On the 13th of
the same month, a letter from Davy to Cuvier was read, in which
he offered a general view of its chemical nature and relations ; and
on the 20th of January, 1814, he communicated to the Royal
Society a long and elaborate paper, dated Paris, December 10,
1813, entitled, 'Some Experiments and Observations on a New
Substance which becomes a violet-coloured Gas by Heat.'
On the 13th of December, Sir Humphrey Davy was elected a
corresponding member of the French Institute, 48 members being
present, and Gayton de Morveau being the only person who opposed
his election.
Life of Sir Humphry Davy. 577
He left Paris for Montpelier on the 29th of December, where
he remained a month, and worked upon the subject of iodine
in the laboratory of M. Berard : from thence he went by way of
Turin to Genoa, and then proceeded to Florence, where he experi-
mented in the laboratory of the Accademia del Cimento on iodine,
but more particularly on the combustion of the diamond. He
quitted Florence on the 3d of April, and entered Rome on the 6th ;
here he renewed his researches on the combustion of different kinds
of charcoal, and transmitted two papers to the Royal Society, the
one containing his further experiments on iodine, the other * On
the Combustion of the Diamond and other Carbonaceous Sub-
stances.' Dr. Paris observes,
' that the experiments which Davy conducted at Florence and Rome
have removed several important errors in regard to the nature of car-
bonaceous substances ; and though they may not encourage the labours
of those speculative chemists who still hope to exemplify the old proverb
carbonem pro thesauro, by manufacturing diamonds out of charcoal,
they certainly show that they are less chimerical than those of the wild
visionaries who sought to convert the base metals into gold.1
On the 8th of May, he arrived at Naples, and visited Vesuvius
and the volcanic country around it. He also took great interest in
the excavations, at that time going on at Pompeii under Murat,
then King of Naples, who placed at his disposal several specimens
of art, which Davy received with a view to investigate the chemical
composition of the colours used by the ancients. The results of
his inquiry were communicated on the 23d of February, 1815,
in a paper ' On a Solid Compound of Iodine and Oxygen,' on
April 10, and another ' On the Action of Acids on the Salts
usually called Hyper-oxymuriates, and on the Gases produced from
them,' on May 4. Before he finally quitted Italy, he again spent
three weeks at Naples, during which he experimented on iodine
and fluorine in the house of Sementini, and paid several visits
to the crater of Vesuvius. He returned to England through
Germany and Flanders, and arrived in London in April 1815.
The invention of the SAFETY LAMP, of which Dr. Paris has given
a most interesting detail is, as he observes —
* a discovery which, whether considered in relation to its scientific import-
ance, or to its great practical value, is one of the most splendid triumphs
of human genius. It was the fruit of elaborate experiment and close
induction ; chance or accident, which comes in for so large a share of
the credit of human inventions, has no claims to prefer upon this occa-
sion ; step by step he may be followed throughout the whole progress of
his research, and so obviously does the discovery of each new fact
spring from those that preceded it, that we never for a moment lose sight
of the philosopher, but keep pace with him during the whole of his
inquiry.'
His attention was called to the subject by Dr. Gray (now Lord
Bishop of Bristol), then Rector of Bishop Wearmouth, a zealous
member of the association which had been formed *for the Prevent
578 Analysis of Books, 8fc.
tion of Accidents in Coal Mines,' in consequence of the fatal
calamities which had been of such frequent occurrence by the
explosions from fire-damp. Numerous abortive projects had been
proposed to the Society, and some few had commanded their
attention, when Dr. Gray directed Sir H. Davy's attention to the
subject in August, 1815. He was then in Scotland, but immedi-
ately began its investigation.
' He commenced with ascertaining the degree of combustibility of the
fire-damp, and the limits in which the proportions of atmospheric air
and carburetted hydrogen can be combined, so as to afford an explosive
mixture. He was then led to examine the effects of the admixture of
azote and carbonic acid gas ; and the result of those experiments fur-
nished him with the basis of his first plan of security. His next step
was to inquire whether explosions of gas would pass through tubes ; and
on finding that this did not happen if the tubes were of certain lengths
and diameters, he proceeded to examine the limits of such conditions ;
and by shortening the tubes, diminishing their diameters, and multiply-
ing their number, he at length arrived at the conclusion that a simple
tissue of wire-gauze afforded all the means of perfect security ; and he
constructed a lamp, which has been truly declared to be as marvellous
in its operation, as the storied lamp of Aladdin — realizing its fabled
powers of conducting in safety through "fiends of combustion," to the
hidden treasures of the earth. — When it is remembered that the security
thus conferred upon the labouring community is not merely the privilege
of the age in which the discovery was effected, but must be extended to
future times, and continue to preserve human life as long as coal is dug
from our mines, can there be found, in the whole compass of art or
science, an invention more useful and glorious ? '
A subscription was raised by the gentlemen interested in the
coal mines of the Tyne and the Wear, and a service of plate was
presented to Sir Humphry Davy. The lamp was named after him
by the miners, arid is now called a Davy ; and the Emperor of
Russia, to whom he had presented a model of the safety lamp,
honoured him with the present of a handsome silver gilt vase. He
has been heard to declare that the discovery had given him more
satisfaction than anything he ever did, as it served the cause of
humanity, and would save the lives of thousands of poor labourers.
Other interesting results to science have arisen out of the investiga-
tion for constructing a safety lamp. We have been made better
acquainted with the nature of flame and the circumstances by which
it is modified, leading to some practical views connected with the
useful arts. These Davy communicated to the Royal Society, in
January, 1816, for which, and his previous researches on flame
and combustion, the Society adjudged to him the Rumford gold and
silver medals. These communications he put into a form more
accessible to the practical parts of the community, by reprinting
them collectively in an octavo volume, ' On the Safety Lamp, with
some Researches on Flame, 1818.'
Having made some experiments on fragments of the papyri, or
manuscript rolls, which had been found in the ruins of Herculaneum,
Life of Sir Humphry Davy. 579
with apparent success, and Mr. Hamilton having represented the
circumstance to government, he was authorised to proceed to Naples,
and funds were placed at his disposal for paying persons whom
it might be necessary to engage in the process. He embarked at
Dover for the continent in May, 1818. During his journey he
made some interesting observations on the causes of the formation
of mists over the beds of river and lakes, which were communicated
to the Royal Society in February, 1819. In the process of unrolling
the papyri, it appears that Davy was not successful; the failure was
not, however, owing to his want of zeal and skill, but solely to the
unfortunate condition of the rolls. He had succeeded in partially
unrolling some, and the late Rev. Peter Elmsley came to Naples for
the purpose of assisting in transcribing what had been recovered.
This excited jealousy, which the interference of the English ambas-
sador could not entirely remove ; obstructions were thrown in the
way of his future operations, and he abandoned the task at the end
of two months. He returned to England in 1820; and the death
of Sir Joseph Banks, having vacated the chair of President of the
Royal Society, Davy was raised to that high honour. Dr. Wol-
laston, having declined competition, gave him the weight of his
influence; and though a feeble attempt was made in favour of Lord
Colchester, without his knowledge or concurrence, Davy was elected
by an immense majority.
In the winter of 1819, Professor Oersted published an account of
his highly important discovery of the intimate relation of electricity
and magnetism, which has given birth to a new science termed
ELECTRO-MAGNETISM. The discovery was limited to the action of
the electric current on needles previously magnetised. Davy applied
himself with his characteristic zeal to the repetition and variation of
the experiments, and soon ascertained that the uniting conductor
itself became magnetic during the passage of electricity through it.
He communicated the results of his successive experiments on this
subject to the Royal Society, in three papers, published in 1820,
1821, and 1823. The third paper announced the discovery of a
new electro-magnetic phenomenon. These researches are insepa-
rably connected with Mr. Faraday's beautiful experiments on mag-
netic rotation.
Dr. Paris relates in detail the circumstances attendant upon one
of the most important discoveries of modern science, the conden-
sation of the gases; a discovery which he regards, with justice, as
strictly belonging to Mr. Faraday. The circumstances are par-
ticularly interesting, because Dr. Paris was an eye-witness of the
first result, and publicly stated Mr. Faraday's claim immediately
after the event, in a lecture at the College of Physicians. Those
who have read Mr. Faraday's paper in the Philosophical Trans-
actions, and that of Sir H. Davy, will have remarked a discrepancy
in the statements, which the narrative of Dr. Paris will correct.
' Before the year 1810, the solid substance obtained by exposing chlo-
580 Analysis of Books, $c.
rine to a low temperature, was considered as the gas itself reduced into
that form. Davy first corrected the error, and showed it to be a hydrate,
the pure gas not being condensible even at a temperature of 40° Fahren-
heit. Mr. Faraday had taken advantage of the cold season to procure
crystals of this hydrate, and was proceeding in its analysis, when Sir H.
Davy suggested to him the expediency of observing what would happen
if it were heated in a close vessel ; but this suggestion was made after Mr.
Faraday had obtained results which must have led him to the experiments,
had he never communicated with SirH. Davy. On exposing the hydrate,
in a tube hermetically sealed, to a temperature of 100°, the substance
fused, the tube became filled with a bright yellow atmosphere, and on
examination was found to contain two fluid substances : the one, about
three-fourths of the whole, was of a faint yellow colour, having very much
the appearance of water; the remaining fourth, was a heavy bright
yellow fluid lying at the bottom of the former, without any apparent
tendency to mix with it. By operating on the hydrate in a bent tube
hermetically sealed, Mr. F. found it easy, after decomposing it by a heat
of 100°, to distil the yellow fluid to one end of the tube, and thus to sepa-
rate it from the remaining portion. If the tube was now cut in the
middle, the parts flew asunder, as if with an explosion, the whole of the
yellow portion disappeared, and there was a powerful atmosphere of
chlorine produced; the pale portion, on the contrary, remained, and,
when examined, proved to be a weak solution of chlorine in water, with
a little muriatic acid, probably from the impurity of the hydrate used.
When that end of the tube, in which the yellow fluid lay, was broken under
ajar of water, there was an immediate production of chlorine gas. Mr.
Faraday soon perceived that the chlorine had been entirely separated from
the water by the heat, and condensed into a dry fluid by its own abun-
dant vapour. He subsequently confirmed these views by condensing chlo-
rine in a long tube by mechanical pressure.'
To Mr. Faraday's paper, Sir H. Davy thought proper to add a
' note on the condensation of muriatic gas into the liquid form ;'
and on the 17th of April, he communicated to the Royal Society a
paper * On the application of Liquids, formed by the condensation
of Gases, as Mechanical Agents;' which contains the results of several
experiments made, with the assistance of Mr. Faraday, on the differ-
ences between the increase of elastic force in gases under high and
low pressures.
In the latter part of 1823, the government requested the advice
of the President and Council of the Royal Society, as to the best
mode of manufacturing copper sheets, or of preserving them, while
in use as the sheathing of ships, against the corrosive effects of oxi-
dation. Sir H. Davy charged himself with this inquiry, and com-
municated the results in three memoirs, read in January and June,
1824, and in June, 1S25. In these papers he comes to the con-
clusion, that as copper is but weakly positive in the electro-chemical
scale, and can only act upon sea-water when in a positive state,
that by rendering it slightly negative, the corroding action of
sea-water upon it is prevented ; he proposed therefore to render
the copper electro-positive by means of the contact of an easily
oxidable metal. Having communicated his views to his Majesty's
government, an order was made for trying the plan of protection he
Life of Sir Humphry Davy. 581
suggested upon the bottom of a sailing cutter, under his own super-
intendence. Models were also constructed and floated in sea-water
for several months. The experiment seemed conclusive, and the plan
was put into extensive practice. In the month of June, 1824, the
Comet steam-vessel was prepared, to afford him the means of per-
forming his experiments upon the best means of protection, in which
he made a voyage to Heligoland and the Naze of Norway. When
in Denmark, he visited Professor Oersted and Dr. Olbers ; and at
Stockholm he had a transient interview with Berzelius. In June,
1825, he read before the Royal Society his third paper on Cop-
per sheathing; and the subject was continued in his last Bakerian
Lecture, in June, 1826, * On the Relation of Electrical Changes/
for which the royal medal was adjudged to him by the Royal
Society. At the conclusion of this lecture he says, * A great variety
of experiments, made in different parts of the world, have proved the
full efficacy of the electro-chemical means of preserving metals,
particularly the copper- sheathing of ships ; but a hope I had once in-
dulged, that the peculiar electrical state would prevent the adhesion
of weeds or insects, has not been realized — and an absolute remedy
for adhesions is to be sought for by other more refined means of
protection, which appear to be indicated by these researches.'
The vessels, which had their copper-sheathing protected upon the
plan proposed by Sir H. Davy, were found to have their bottoms
completely covered with sea-weed, shell-fish of various kinds, and
myriads of small marine insects, the copper near the protectors being
much more foul than at a distance from them ; and the incon-
venience attending this circumstance was so great, as to cause the
plan to be abandoned altogether, after long-continued trial, under
various circumstances, in 1828.
Dr. Paris gives a detailed account of similar experiments made in
France, on La Constance frigate, which were attended with similar re-
sults ; and informs us, that further experiments are about to be tried
in the British navy, founded on the same principle. Sir H. Davy
experienced disappointment and chagrin at the failure of his plan,
wholly inconsistent with the merits of the question; but his health was
now declining, and this produced, no doubt, that morbid sensibility
and irritation which his friends witnessed with pain. At the close of
the year 1826, his indisposition increased: he complained of pal-
pitation of the heart, and an affection of the trachea, and was
unable to walk without fatigue. In January, 1827, he published
the Discourses which he had delivered before the Royal Society, on
awarding- the Copley Medals, to which was prefixed his Discourse
on taking the chair of the Royal Society for the first time, which
contains some passages of interest, prophetic of future discoveries.
"While on a visit to Lord Gage, at the close of 1826, he felt more
than usually unwell, and determined to return to London : while on
his journey, he was seized with an apoplectic attack at Mayersfield;
prompt and copious bleeding on the spot arrested the symptoms
VOL. I. MAY, 1831. 2 Q
582 Analysis of Books, fyct
threatening- life, and he reached home. As soon as the more im-
mediate danger of the attack had passed away, he was advised to a
residence in the South of Europe, and accordingly quitted England
with the intention of wintering in Italy. Feeling that his recovery
was tardy, and that mental repose was necessary for its advance-
ment, he determined to resign the chair of the Royal Society, and
announced his intention in a letter to Mr. Davies Gilbert, who was
appointed to fill the chair till the next anniversary, and ultimately
was elected to succeed him.
He returned to London in October, 1827, for the benefit of medi-
cal advice ; again visited his friend Lord Gage in Sussex, and passed
a short time with his friend, Mr. Poole, at Stowey. His bodily
infirmity was then very great, and his sensibility painfully alive on
every occasion. In this period of suffering he amused himself with
writing his Salmonia, or Days of Fly-fishing (written in emulation
of that delightful piscatory pastoral the ' Complete Angler'). This
was published in the spring of 1828. It contains many pleasing
illustrations of .facts in natural history. Dr. Paris has given some
interesting extracts, and thus defends the writer : ' If the advanced
age of Walton was pleaded by himself as a sufficient reason for pro-
curing " a writ of ease," the friends of Davy may surely claim, at
the hands of the critic, an indulgent reception for a congenial work,
written in the hour of lassitude and sickness.'
His paper, * On the Phenomena of Volcanoes,' was read before
the Royal Society on the 20th of March, 1828, just before he
quitted England on his last journey ; and he communicated a paper
on the Electricity of the Torpedo, which is dated from Luciana in
Illyria, in October, 1828. He concludes the paper by expressing
his fear that the weak state of his health will prevent him from
pursuing the subject with the attention it seems to deserve. His
last production was ' Consolations in Travel, or the Last Days of a
Philosopher,' which was published by his brother Dr. Davy, after
his decease. He informs us in the preface, that it was composed
immediately after * Salmonia.' under the same painful circumstances.
From this exercise of the mind, he says he derived some pleasure
and some consolation, when most other sources of consolation and
pleasure were closed to him ; and he ventures to hope that those
hours of sickness may be not altogether unprofitable to persons in
health. This work is too generally diffused to render it necessary
that we should enter into a detail of its contents, had we space to
do so. Dr. Paris has given large extracts, and thus expresses his
opinion of its claim to attention : —
* This is a most extraordinary and interesting work ; extraordinary, not
only from the wild strength of its fancy, and the extravagance of its con-
ceptions, but from the bright light of scientific truth which is constantly
shining through its metaphorical tissue, and irradiating its most shadowy
imaginings. It may be compared to the tree of the lower regions in
the ^Eneid, to every leaf of which was attached a dream, and yet, how-
ever wildly his fancy may dream, his philosophy never steeps ; and in his
exit from the land of phantoms, the author can in no instance be accused
Life of Sir Humphry Davy. 583
of having mistaken the gate of ivory for that of horn. To the biographer,
the work is of the highest interest and valu«, by confirming in a remark-
able manner the opinion so frequently expressed in the course of these
memoirs, with respect to the diversified talents of Sir Humphry Davy ;
and above all by elucidating that rare combination of imagination with
judgment, which imparted to his genius its most striking particularities/
Davy's latter days were cheered by the affectionate attentions of
Mr. James Tobin, his godson, who was the companion of his
travels. He resided at Rome for some months, but declined re-
ceiving any visitors ; his only solace was to have some one reading
to him light works of interest, which was continued even during
his meals. As soon as the account of his having sustained another
paralytic seizure reached Lady Davy, who was in London, she
hastened to join him, and reached Rome in about twelve days.
Dr. John Davy, on receiving intelligence of his brother's imminent
danger, came to him from Malta : he only partially recovered from
this attack, and though there appeared some faint indications of
reviving power, his most sanguine friends scarcely ventured to
indulge a hope that his life would be much longer protracted. With
that restlessness characteristic of his disease, he became extremely
desirous of removing from Rome to Geneva. His friends were
anxious to gratify his wish, and travelling by easy stages he reached
Geneva at three o'clock on the 28th of May, accompanied by Mr.
Tobin and his servant, Lady Davy having preceded him to make
arrangements for his reception. At four o'clock he dined, ate heartily
and was unusually cheerful, he drank tea at eleven, and retired to
rest at twelve. His servant, who slept in his room, was very shortly
called to attend him, he desired his brother might be summoned,
and he expired at a quarter before three without a struggle.
The public authorities of Geneva honoured his remains with a
public funeral after the custom of Geneva, which was attended on
foot by the magistrates, the professors, and the English residents at
Geneva. A tablet has been placed to his memory in Westminster
Abbey, by his widow, but, as yet, no national monument has been
devised to commemorate the service he has rendered to science,
his country, and mankind. It is said that the inhabitants of Pen-
zance and its neighbourhood are about to raise a pyramid of massive
granite to his memory, on one of those elevated spots where he
delighted in his boyish days to commune with the elements.
* The fame of such a philosopher as Davy,' says his Biographer, ' can
never be exalted by any frail memorial which man can raise. His monu-
ment is in the great Temple of Nature, his chroniclers are Time and the
Elements. The destructive agents which reduce to dust the urn, the
statue, and the pyramid, were the ministers of his power, and their work
of decomposition is a perpetual memorial of his intelligence.'
Though this analysis of Dr. Paris's work has run out to an un-
reasonable length, we must indulge in the quotation of his judicious
comparison of the characters of two illustrious philosophers; it is an
acceptable enlargement of their intellectual portraits so ably drawn
by Dr. Henry.
2 Q 2
584 Analysis of Books, $c.
• In contrasting the genius of Wollaston with that of Davy, let me not
be supposed to invite a comparison to the disparagement of either, but
rather to the glory of both, for by mutual reflection each will glow
the brighter. — If the animating principle of Davy's mind was a powerful
imagination, generalizing phenomena, and casting them into new combi-
nations, so may the striking characteristic of Wollaston' s genius be said.
to have been an almost superhuman perception of minute detail. Davy
was ever imagining something greater than he knew ; Wollaston always
knew something more than he acknowledged: — in Wollaston, the pre-
dominant principle was to avoid error ; in Davy it was the desire to
discover truth. The tendency of Davy, on all occasions, was to raise
probabilities into facts ; while Wollaston as continually made them sub-
servient to the expression of doubt.
' Wollaston was deficient in imagination, and under no circumstances
could he have become a poet, nor was it to be expected that his investi-
gations should have led him to any of those comprehensive generalizations
which create new systems of philosophy. He well knew the compass of
his powers, and he pursued the only method by which they could be
rendered available in advancing knowledge. He was a giant in strength,
but it was the strength of Antaeus, mighty only on the'earth. The ex-
treme caution and reserve of his manners were inseparably connected
with the habits of his mind ; they pervaded every part of his character ;
in his amusements and in his scientific experiments, he displayed the same
nice and punctilious observation,— whether he was angling for trout, or
testing for elements, he alike relied for success upon his subtile discrimi-
nation of minute circumstances.
* By comparing the writings as well as the discoveries of these two
great philosophers, we shall readily perceive the intellectual distinctions
I have endeavoured to establish — " From their fruits shall ye know
them." The discoveries of Davy were the results of extensive views and
new analogies, those of Wollaston were derived from a more exact ex-
amination of minute and, to ordinary observers, scarcely appreciable dif-
ferences. This is happily illustrated by a comparison of the means by
which each discovered new metals. — The alkaline bases were the pro-
ducts of a comprehensive investigation, which had developed a new order
of principles ; the detection of palladium and rhodium among the ores of
platinum, was the reward of delicate manipulation, and microscopic
scrutiny.' — ' The chemical manipulations of Wollaston and Davy offered
a singular contrast to each other, and might be considered as highly
characteristic of the temperaments and intellectual qualities of these
remarkable men. Every process of the former was regulated with the
most scrupulous regard to microscopic accuracy, and conducted with the
utmost neatness of detail. It has been already stated with what turbulence
and apparent confusion the experiments of the latter were conducted, and
yet each was equally excellent in his own style ; and as artists they have
not unaptly been compared to Teniers and Michael Angelo. By long
discipline, Wollaston had acquired such power in commanding and
fixing his attention upon minute objects, that he was able to recognise
resemblances, and to distinguish differences, between precipitates pro-
duced by re-agents, which were invisible to ordinary observers, and
which enabled him to submit to analysis the minutest particle of matter
with success. Davy, on the other hand, obtained his results by an
intellectual process, which may be said to have consisted in the extreme
rapidity with which he seized upon, and applied appropriate means at
appropriate moments.'
585 )
Ada Academic Chn, Moray. SmV. 1631.
n -i-
y . Sinujj-y. /33 7.
•
INDEX.
ACADEMY of Sciences in Paris, proceed-
ings of, 558.
Acid, account of pyrophosphoric, 167.
hydrocyanic, produced under un-
common circumstances, 169.
malic, preparation and composition
of, 178.
•" para-tartaric, 395.
nitric, distillation of, 402.
Aconitum ferox, account of the poison
obtained from the, 365, 366.
Acoustic rainbow, 375.
Action of chlorine on carburetted hy-
drogen, 169.
- of the galvanic pile upon living
animal substances, 186.
of mixed nitrate and muriate of
ammonia on glass, 385.
• of oil of turpentine on the ner-
vous system, 565.
Acupuncturation of the arteries, 565.
Adriaansz's claim to the invention of
telescopes, 320.
Aeorolite, account of one that fell in
Georgia, in 1829,415.
Affections of the vocal organs, 565.
Agricultural labours of the ancients re-
gulated by the rising of remarkable
stars, 459.
Ahrweiler, account of the mode of vault-
ing used at the church at, 225.
Aiiiger, Mr., on the darkness between
the primary and secondary rainbows,
281 — remarks upon the theory of M.
Biot, 282 — geometrical illustrations,
ibid. — the phenomena more clearly
explained, 291.
. on machinery employed in pencil
making, 555.
Ainsworth's, Mr., observations on Mr.
Rennie's paper relating to the clean-
liness of animals, 261.
remarks on the ages of
rocks, 547.
Air, changes effected in the atmospheric,
by leaves, 93.
"• change of, in eggs, during incuba-
tion, 435.
Aire, quantity of gaseous bodies in the
waters of the, 45.
Almond, Mr.,
VOL. I,
the supply of water between rivulets
and canals, 307.
Alloys of lead and tin, action of mer-
cury upon, 1.
• peculiar property
of, 404.
Alumine, remarks upon its power of
purifying water, 41.
Amalgamation, mode of reducing metals
by, 145.
Amici, M., on the growth of vegetables,
422.
experiments on the leaves of
celadine, 560.
Ammonia in native oxide of iron, 174.
compounds of, with anhydrous
salts, 620.
Amusat's, M., cases in which the twist-
ing of arteries had been performed
with success, 564.
Analysis of books, 142, 337, 571.
of chloride of gold, and potas-
sium, 409.
410.
and sodium,
of a plant, 87.
Anatomical investigation of the struc-
ture of the eyes in insects, 152.
Andrieux's, Dr., improved galvanic ap-
paratus, 564.
Animal poisons, cure of, by the applica-
tion of common salt, 189.
substances, action of the galva-
nic battery upon living, 186.
Animals, on the tract of, in the forest
marble, 538.
Animalculae, existence of, in snow, 193.
Ants, care of, to secure warmth, 517.
Apatite, electric experiments upon, 79.
Ape, remarks upon the Barbary, 500.
Apophillite, analysis of, 443.
Apparent hydrostatic anomaly with laurel
oil, 161.
Apples, russet in, 638.
Arago's, M., observations on the aurora
borealis, 558.
Ararat, Parrot's expedition to, 419.
Aratus, remarks upon, relating to the
rising of the Dog-star, 471.
Argonautic expedition, observations
upon the. 62,
, 1831. 2 U
646
INDEX.
Arsenic, a good test for, 173.
Arteries, twisting of the, 564.
Atmosphere, tides in the, 559.
Atmospheric phenomena, described by
Professor Strehlke, 432.
Atomic weight of titanium, 175.
Ava root, medicinal use of the, 639.
Aubert, M., on the spontaneous inflam-
mation of charcoal, 617.
Aurora borealis, account of an irised,
198.
by Mr. Christie, 262.
influence of, on the
magnetic needle, 429.
account of, by Dr.
Moll, 519.
— — observations upon the,
by the Hon. C. Harris, 522.
by M. Arago, 558.
height of the luminous
arch above the earth's surface, 525.
B.
BAKER'S account of the wheel animalcula,
221 — remarks on the apparent circu-
lar motion, 222.
Barometer, improved mountain, 555.
new construction of a, 601.
Battery for electro-magnetic purposes,
remarks upon the construction of a.
35.
Becquerel's error in estimating the con-
ducting power of wires, 36.
, *rr— on the electrical state of bodies
by the action of heat, 568.
Bees, account of Mexican domestic, 640.
Beltrami's, M., account of a two-headed
lizard, 570.
Bennati, on the mechanism of the human
voice, 185.
•i on the affections of the vocal
organs, 565.
Berzelius's remarks upon para-tartaric
acid, 395.
. • method of preparing urea,
401.
— on the combination of chloride
of gold, with chloride of potassium
and sodium, 409.
test of the protoxide and per-
oxide of iron, 624.
Bevan, on the compression of lead,
157.
.. . on the power of horses, 159.
Bi-carbonate of soda, mode of preparing,
385.
Bicheno, Mr., on the plant intended by
the shamrock of Ireland, 453.
Biot, M., on remarks upon his theory of
rainbow, 282.
• • i his calculation of the com-
mencement of the Egyptian year,
473.
Birds, peculiar cleanliness of, 25.
of prey, on the vision of, 192.
their care to secure warmth, 505.
Bismuth, crystallization of, 393.
and its alloys, expansion of,
during congelation, 411,
Blood, mode of preserving, 398.
presence of manganese in, 399.
Bodies, change of volume in, when they
combine together, 160.
Bonijol's apparatus for decomposing
water by atmospheric electricity, 376.
for decomposing potash, ibid.
Botany of India, by Dr. Wallich, ana-
lysis of the, 360.
Bonnycastle's, Captain, observations on
the phosphorescence of the sea, 194.
Boullay, M., on the change of volume
in bodies when they combine together,
160.
on ulmin, 179.
Boussingault, M., on ammonia in native
oxide of iron, 174.
Bowdoin's, Mr., account of an irised
aurora borealis, 198.
Braconnet, M., on caseum and milk,
181.
Brande, Mr., on the electro-chemical
decomposition of the vegeto-alkaline
salts, 250.
. on the relation of the vegeto-
alkalies to the common alkalies, and
to certain proximate principles of
vegetables, 547.
Brewster, Dr., on the laws of elliptic
polarization, as exhibited in the action
of metals upon light, 340.
Bromic and chloric acids, action of
alcohol upon, 615.
Bromide of carbon, mode of preparing,
Brongniart, on the smut in corn, 420.
on the structure of leaves,
421, 636.
Brown's, Lieutenant, experiments on
the stiffness and strength of timber,
599.
Browne's moving molecules, easy mode
of exhibiting, 369.
Bullet, mode of preventing its discharge
from a gun, by the finger, 368.
Burnett, Mr., on the development of the
several organic systems of vegetables,
83 — remarks upon the functions of
plants, 84 — analysis of a plant, 87 —
remarks on the death of trees, when
the roots are too thickly covered with
earth, 89 — observations on the motion
of the sap in plants, 90— changes
INDEX.
647
produced iii atmospheric air by leaves,
95.
Busses, M., method of obtaining mag-
nesium, 562.
C.
CADMUS, remarks upon the origin of
the fable, 60.
Calculous diseases, on the tendency to,
by Dr. Yelloly, 316.
Cambium, remarks upon, in the forma-
tion of wood and bark, 478.
Camphor, composition of, 631.
Canals, mode of regulating the supply
of water between rivulets and, 307.
Caseum and milk, memoir on, 181.
Cat, natural cleanliness of the, 23.
• mode of cleaning itself, ibid.
— — its care to secure warmth, 497.
•• difference between the wild and
domestic, 499.
Cathedral at Cologne, remarks upon the
vaulting of the choir, 235.
Cavalier, M., on discoloured chloride of
silver, 393.
Cauchy, M. A. L., on the integration of
differential equations, 596 — on series,
ibid. — on the moments of inertia of a
solid, 597 — on a system of molecules,
ibid. — on the theory of light, ibid. —
demonstration of the law relating to
solids and fluids, 598 — memoir on
torsion, ibid.
Ceres, remarks upon the fabulous history
of, 59.
Chameleon, its antipathy to black,
194.
Charcoal most suitable for the manu-
facture of gunpowder, 131.
-• new process in the manufac-
ture of, 184.
Chemical notation, observations on the
necessity of a, by Rev. W. Whewell,
437.
Chevalier, M., on the thermal water of
Chaudes Aigues, 417.
Chloride of silver, remark upon the dis-
coloured, 393.
of gold, and potassium, analysis
of, 410.
— — — — — and sodium, analysis of,
ibid.
Chlorine, action of, upon carburetted
hydrogen, 169.
. an antidote to hydrocyanic
acid, 188.
Chlorophane, electrical experiments
upon, 77.
its phosphorescence restored
by electricity, 78.
Cholera morbus, observations on, by
Dr. Jahinichen, 567.
Christie, Mr., on the permanence of
magnetism in steel bars, 243.
on the aurora borealis, 262.
on the height of a luminous
arch of the aurora hurt-alls above the
surface of the earth, 525.
Chronology of the Egyptians, 458.
Circulation in vegetables, 424.
in plants, remark* on the,
Clarke, Mr., on pyrophosphates, 167.
Cleaning instrument of the larva of the
glow-worm described, 17.
Clement's experiment, easy mode of
repeating it, 369.
Clemson's, Mr., mode of preparing pi-
perin, 395.
Climate of England, remarks upon the,
by Mr. Knight, 642.
Clover (Trifolium repent), not the ori-
ginal emblem of Ireland, 453, 454.
Cold, never sufficiently intense to stop
the evaporation of water, 70.
Coloured bands, experiments on, by Mr.
Quitelet, 164.
Columbine, a new vegetable principle,
630.
Comet, account of a, by Mr. Dabadie,
241.
Compression of fluids, experiments upon
the, 375.
Contributions to the physiology of
vision, No. I., 101 ; No. II., 534.
Copper and zinc, voltaic action produced
from a few grains of, 32.
Coriolis's, M., experiments on the com-
pression of lead, 158.
Coxe's, Dr., mode of preparing phos-
phuret of lime, 173.
Cowper, Mr., on recent improvements in
paper making, 552.
Cuticular pores of plants, 419.
Cutting instruments, new mode of set-
ting, 13.
Cuvier's theory of vision, 536.
Cyanogen in the blood, 186.
D.
DAB.VDIK'S, M., account of a new comet,
241.
Dahlias, new mode of multiplying, 424.
Danaides, remarks upon the fable of the,
68.
Daniell, Mr. J. F., on the phenomena
resulting from the action of mercury
upon different metals, 1 — action of mer-
cury upon an alloy of lead and tin, ibid.
— remark upon the nature and result
2U2
648
INDEX.
of this experiment, 2 — upon pure tin,
ibid. — upon lead, 3 — upon zinc, ibid.
— upon silver, 4 — upon gold, ibid. —
upon tin, 5, 6, 7 — remarks upon ham-
mering metals, 6— experiment with
spongy platinum, 10 — general obser-
vations upon the process and results
of these experiments, 1 1 .
Daniell, Mr. J. F., on a new register
pyrometer, 338.
Davy, Sir Humphry, analysis of the
life of, by Dr. Paris, 347— account of
his birth and family, ibid. — education,
ibid. — his first experiments in che-
mistry, 348 — appointed chemical as-
sistant to the Pneumatic Institution of
Bristol, 349 — interesting experiment
with two pieces of cane, 351 — new
galvanic experiments, 352 — appointed
assistant lecturer in chemistry to the
Royal Institution, ibid. — galvanic
battery without metallic substance,
853 — appointed professor of chemistry
to the Royal Institution, 354— elected
Fellow of the Royal Society, 35 G —
— decomposition of the alkalies, 358
— his chloridic theory, 572 — his mar-
riage, 573 — Mr. Faraday's first intro-
duction to him, 575 — invention of the
safety-lamp, 577 — death, 583 — com-
parison of the characters of Davy and
Wollaston, 583.
Daubeny, Dr., on the occurrence of
iodine and bromine in mineral waters
of South Britain, 337.
D'Aubuisson. M., on the resistance op-
posed to water moving in pipes, 157.
Degree, the exact measure of a, 370.
De Lassaux's mode of erecting light
vaults over chixrches and similar
spaces, 224.
Detonating matches, Dr. Ure on, 140.
Diamonds made phosphorescent by heat,
after electrization, 32.
Dipping needle, improvement in the
construction of the, 60S.
Domes, account of, erected at Vienna,
without centering, 224, 225.
Donati, Dr., on the phenomena observed
during the last eruption of Vesuvius
in 1828, 296 — sudden shock and
eruption, 298 — discharge of liquid
lava, 300 — explosion of gas, 304 —
vertical section of the great cone, 306.
Doolittle, Mr., account of the manufac-
ture of charcoal by, 184.
Drowning, restoration from, by insuffla-
tion of the lungs, 190.
Drummond, Lieutenant, on the illumi-
nation of light-houses, 344.
Dtiberga, M., on the power of carbon
to destroy bitterness in certain bodies,
619.
Dumas, M., on oxamide, 382.
Duperrey, L. J., on the figure of the mag-
netic equator, 607.
Du Petit Thouars, remarks upon his
theory of the growth of wood, 479,
480.
Dutrochet's remarks upon the circulation
in celadine, 561.
E.
EGGS, change of air in, during incuba-
tion, 435.
Egyptian chronology, by Professor
Renwick, 458 — agricultural labours
of the ancients regulated by the
heliacal rising of remarkable stars,
459 — earliest settlement of a colony
in Egypt, 462 — Sothic period, 463
— Chaldean records used by Ptolemy,
464 — remarks upon the origin of
letters, 466 — chronologies compared,
468.
Elastic fluid, remark upon the velocity
of an, 599.
Elaterium, new principle obtained from,
532.
Electrical accumulation, laws of, 380.
relation of bodies to heat, 568.
Electricity increased by a double copper
plate, 34.
of the winds, 198.
effects of, upon fluor spar,
271.
Electro-magnetic telegraph, remarks
upon an, 37.
magnet, account of a powerful,
by Professor Moll, 379.
magnets, account of powerful,
by Professor Henry and Dr. Tea
Eyck, 609.
Elevation of the Morea, 563.
Elk, description of the horns of the
Prussian, 118.
Elliptic polnrization,laws of, as exhibited
in the action of metals upon light,
340.
Elm-trees, cure of wounds in, 200.
Emmett, Professor, on iodide of potas-
sium as a test for arsenic, 173.
on the preparation
of nitrogen, 384.
English yard, proportion between the,
and French metre, 599.
Erman, M., on the direction and inten-
sity of the magnetic force at St. Pe-
tersburgh, 604.
Eye, surgical recovery of an,*191.
INDEX.
649
Eye globules in the humours of the,
185.
F.
FABULOUS history of Greece, elucidation
of some portions of the, by Mr.
Sankey, 57.
Faraday, Mr., on the limits of vaporisa-
tion, 70.
• • on a peculiar class of optical
deceptions, 205, 333, 334.
••• on wheel animalculae, 220.
on Clement's paradoxical expe-
riment, 369.
• his introduction to Sir H. Davy.
575.
— — — his condensation of the gases,
579, 580.
Feathers, mode of restoring the elas-
ticity of, when damaged, 427.
Fern owl (Caprimu/gus Europafus}^' de-
scription of the cleaning instrument
of the, 21.
Fischer, Rev. J., on the cure of animal
poisons by the application of common
salt, 189.
Flea, remarks upon the care of the, to
secure warmth, 518.
Flies, remarks upon the construction of
their feet, 24.
Fluids, experiments on the compression
of, 375.
on the equilibrium of, 595.
Fluor spar, electric experiments upon,
by T. Pearsall, 81.
• effects of repeated electric
discharges upon, 270, 271.
Flourens, M., experiments on the action
of oil of turpentine upon the nervous
system, 565.
Force of terrestrial magnetism, 374.
Fox, Mr., on the electro-magnetic pro-
perties of the metalliferous veins of
Cornwall, 345.
on the discharge of a jet of
water under water, 368, 599.
Fredonia, village of, lighted by natural
gas, 203.
French method of purifying nitre, 123,
124.
Fruit-trees, mode of preserving, from the
bites of hares, 200.
Fruit, progress of maturation in, 559 —
mode in which the saccharine matter
is produced, 560.
Fuch's, M., mode of extracting potash
from feldspar, 184.
G.
GALVANIC currents during the decompo-
sition of water, 166.
Galvanic pile, action of the, upon liv-
ing animal substances, 186.
apparatus improved, for me-
dical purposes, 564.
Galvanism, on the application of, 566.
Galvanometer, description and use of
the, in electro-magnetic researches,
29.
experiments with, 32.
Gamboa, F. X. de, on the mining ordi-
nances of Spain, 142.
Gas, village lighted by natural, 203.
Gases, emission of light during the com-
pression of, 381.
Gay Lussac, M., on the absorption of
oxygen by silver at high temperatures,
Geoffrey de St. Hilaire, M., on the fos-
sil remains of the Teleo Saurus, 569.
Gergonne, M., on the apparent pro-
jection of stars upon the moon's disc,
163.
Gipsies, hardihood of, 505.
Glass, elasticity of the threads of, 29,
556.
mode of preparing, 31.
method of perforating, 633.
Glow-worm, cleanliness of the grub of
the, 15— description of its cleaning
instrument, 17 — proved to be car-
nivorous, 20 — remarks upon the light,
21.
Gold, action of mercury upon, 4.
on the crystallization of, by Pro-
fessor Henslow, 176.
on the composition of fulminating,
394.
on chloride of, and potassium, by
Berzelius, 409.
and platina district of Russia,
418.
and silver, produce of, in the Rus-
sian empire, 434.
Gothic architecture most appropriate
for churches, 224.
Greece, fabulous history of, 57.
Grew's experiment on the formation of
wood, 477.
Growth of vegetables (Amici), on the,
422.
Gruithnisens, Dr., anatomy of the Nais
diaphana, 593.
Guijot and Admyrauld, MM., on the
seat of the sense of taste, 425.
Gunpowders and detonating matches,
Dr. Ure on the manufacture of, 121.
table of different compo-
sitions, 136.
H.
HAIL; remarks upon the theory of the
formation of, 415.
650
INDEX.
Hall's, Dr. M., observations on Dr. Ar-
nott's explanation of the nature of
stammering, 253.
on the mechanism of vo-
miting, 265.
Hammering, remarks upon the. of me-
tals, 6.
Hancock, Dr., upon an apparent hy-
drostatic anomaly with laurel oil,
161.
Harris, Mr., on the laws of electrical
accumulation, 380.
on the power of various
substances to intercept magnetism, 549.
— — — Hon. Charles, on the aurora
borealis, 522.
Hayes, A. A., on the production of
prussic acid under uncommon circum-
stances, 169.
Hennell, Mr., on elatinum, 532.
Henslow, Professor, on the crystalliza-
tion of gold, 176.
Hermes, remarks upon the fable of, 65.
Herschell, Mr., observations upon the
utility of his chemical nomenclature,
440, 442.
Herodotus, remark upon a passage in,
by Professor Renwick, 459.
Hieroglyphic system, observations upon
the, by Professor Renwick, 458.
Home, Sir E., structure of the feet of
flies first observed by, 24.
Houlton, Mr., bulbous root of great
antiquity produced by, 196.
• ' market state of hyoscia-
mus by, 196.
Horns of the Prusian elk and American
moose deer, 118.
Horses, on the power of, 159.
Horus Apollo, remarks upon the anti-
quity of, 470.
Huber Burnand, M., on the snow in
the winters 1829 and 1830, 196.
Human voice, memoir on the mecha-
nism of the, in singing, 185.
Humboldt's, M., account of the gold
and platina district of the Russian
empire, 418.
*" • on the produce of gold
and silver in the Russian empire, 434.
Map of heights, account
of, 563.
Hybernating animals, observations on
the blood vessels of the head of, 585.
Hyosciamus, market state of, 196.
I.
ICHTHYOLOGY, 429.
India, mirage of Central, 201.
Indian birds, notice of Mr. Gould's col-
lection of, 428.
Indigo, new kind of, 397.
Influence of the age of parents upon
the sex of children, 199.
Insects, on the structure of the eyes of,
152.
i on a peculiar system of visceral
nerves in insects, analogous to the
sympathetic, 586.
lodic acid, on the preparation of, 614.
precipitation of the vegeto4
alkalies by, 615.
Iodide of potassium, a test for arsenic,
173.
Iodine, on the disorders arising from
the long-continued use of, 187.
.1 and bromine in mineral waters,
337.
Irised aurora borealis, account of an, 198.
Iron, persalts of, reaction of the, and
neutral carbonates, 388.
J.
JAHN, Dr., on the use of iodine, 187.
Jahinichen on cholera morbus, 567.
Johnson, Dr., on the vision of birds of
prey, 192.
's, Mr., experiments on steam
generated by heated metal, 613.
Josephus, remarks upon his chronology,
469.
Journal of the weather at Madagascar,
50, 51.
K.
KATEB, Captain, on the error in stand"
ards of linear measure, 343.
Kelkoa or planera tree, wood of the,
recommended for useful purposes,
559.
Kemp, K. T., on the conducting powers
of liquified gases, 613.
Knapp, Mr., remark upon his conjecture
respecting the light of the glow-worm,
20 — relating to the cleanliness of ani-
mals, 26.
Knight, Mr., on the means of giving a
fine edge to razors and cutting instru-
ments, 13.
remarks upon the climate
of England, 642.
Kupffer, M., on the influence of the
aurora borealis on the magnetic
needle, 429.
— — new construction of a baro-
meter, 601.
. on the intensity of the earth's
magnetism, 610.
L.
LANCETS, new mode of giving a fine
edge to, 13.
INDEX.
651
Languages, remarks upon the analysis
of; 57.
Lassau's, M. de, description of a mode
of erecting light vaults over churches
and similar spaces, 224.
Laurel oil, apparent hydrostatic ano-
maly with, 161.
Lead, action of mercury upon, 3.
resistance of, to pressure, 157.
Leaves, M. Brongniart on the structure
and functions of, 421, 636.
Leroux's, M., memoir on salicine, and
its powers as a febrifuge, 177.
Letters, remarks upon, by Professor
Kenwick, 466.
Liebeg, M., on the preparation and com-
position of malic acid, 178.
— • on magnesium, 411.
• on the composition of cam-
phor and camphoric acid, 631.
Light-houses, on the illumination of, by
Lieutenant Drummond, 344.
Light, emission of, during the com-
pression of gases, 381.
of the glow-worm, remarks upon
the, 20.
Limits of vaporization, 70.
Linear measure, error in standards of,
343.
Linley's, Mr., account of a remarkable
instance of anomalous structure in
the trunk of an exogenous tree,
476.
remarks upon the theories of
the formation of wood, 477 — nature
of plants explained, 479.
Lippershey, Hans, the original inventor
of the telescope, 324. 1
Lithia, mode of preparing, 386.
Lithotricity, remarks on, by Dr. Civiale,
564.
Loewig, M., on the preparation of bro-
mide of carbon, 171.
Lubbock's, Mr., researches in physical
astronomy, 342.
Luetke's, Captain, pendulum observa-
tions, 602.
Luminous figures produced by rapid
alternations of light and shade, 102 —
by pressure on the eye-ball, 1 04 — by
galvanism, 107 — rings occasioned by
lateral pressure, 115.
Lungs, insufflation of the, in cases of
drowning, 190.
Lyall's, Mr., remarks upon the weather
at Madagascar, 47— rj6,
M.
MADAGASCAR, remarks upon the weather
at, 47.
Magnesium, M. Liebeg on, 411.
mode of obtaining, 562.
Magnetic needles, mode of preparing
for electro-magnetic experiments, 31.
• curve, geometric properties of
the, 3 1 1 — description of an instrument
for describing it, 315.
needle, dip of the, at St.
Petersburgh, 604.
— force, intensity of the, at St.
Petersburgh, 604.
equator, figure of the, 607.
Magnetism, on the permanence of, in
steel bars, 243.
power of bodies to inter-
intensity of the earth's,
cept, 549.
610.
Majendie and Desmoulin's observations
on the disappearance of luminous ob-
jects, 535, 537.
Magnus's, M., mode of preparing sele-
nium, 619.
Malic acid, preparation and composition
of, 178.
Manganese, method of ascertaining the
value of the ores of, 293.
Marsh, Mr., on the mode of perforating
glass, 633.
Marx, Professor, on the expansion of
bismuth upon congelation, 411.
Maunoir's, M., account of the surgical
recovery of an eye, 191.
Matteucci's, M., experiments on living
animal substances, 186.
on the origiu of the ac-
tion in the voltaic pile, 612.
Maturation of fruit, 559.
Mental spectra, 114.
Mercury, action of, upon different me-
tals, 1.
Metallic specula, quantity of light re-
flected by, 162.
rods, power of, to decompose
water after the connexion with the
pile is broken, 167.
Meteor and aerolite in Georgia, 415.
Meteoric stones, remarks upon a theory
of the formation of, by Mr. Faraday,
72.
Meteorological results, 641.
Metre and English yard, proportion be-
tween the, 599.
Mica, use of, in minute chemical analy-
sis, 633.
Microscope, first invention of the, 484.
Milk and caseum, memoir upon, 181.
Mineralogy, Professor Whewell's re-
marks upon the necessity of the em-
ployment of notation in, 437.
Mirage of Central India, 201.
652
INDEX.
Missol, Dr. F.