Quarterly Journal of Science, Literature and the Arts

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THE

QUARTERLY JOURNAL

SCIENCK,

LITERATURE, AND THE ARTS.

VOLUME XVII.

LONDON:
JOHN MURRAY, ALBEMARLE-STREET.

———.

1824.

LONDON?
PRINTED BY WILLIAM CLOWES,
Northumberland-court.

CONTENTS

OF

THE QUARTERLY JOURNAL,

No. XXXII.

ART. PAGE

TI. On some Phenomena relating to the Formation of Dew on Me-
tallic Surfaces. By Georce Harvey, M.G.S., &c.&e.. .

II. Description of Two New and Remarkable Fresh Water Shells:
Melania setosa and Unio gigas. By Witttam Swainson, Esq.,
F.R.S., M.W.S., &. . 2 +» ee ee ee

III. On Indistinctness of Vision, caused by the presence of False

Light in Optical Instruments ; and on its Remedies. By C. R.
Gorine,, MEDPiu Ge oyowll’ b gigi! ogo 4,00, iegine 4%

IV. The Characters of several New Shells, belonging to the Linnzan

Volutz, with a few Observations on the present State of Con-
chology. By Witt1am Swanson, Esq., F.R.S. &c. .

V. Account of the Earthquake in Chili, in November, 1822, from
Observations made by several Englishmen residing in that Coun-
try. (Communicated by F.Puace, Esq.) . . 6. «, ;.

VI. On Evaporation, By I, Freperic Daniett, Esq., F.R.S.,
Man Ol, ng ae SS ee ke le we

VII. A Design for making a Public Road under the Thames, from
the east side of the Tower, near Iron-Gate Stairs, to the opposite
side of the River, near Horseleydown Stairs. By Samuen
ee a en ae oS aes ae ie it eke oe

VIII. An Account of the Overflowing Well in the Garden of the
Horticultural Society at Chiswick. (Communicated by Josern
Sapine, Esq., Sec. H.S., &c.).

IX. On the Taylorian Theorem

X. Astronomical Phenomena, arranged in Order of Succession, for
the Months of April, May, and June, in the Year 1824...

13

17

28

38

46

it CONTENTS.

Arr. PAGE

XI, Astronomican ann Nautica, Conuectrions, No. XVII.

i. Remarks on the Catalogue of the Orbits of the Comets that have

been hitherto computed. By Dr. Ovpers . . . . . . . . + 85

“iil. Further remarks on the periodical Comets, (86 Olb.) with con-
jectures on the effect of a resisting medium. By Professor ENCkR 96

iii. Comparison of the New Tables of Refraction, with observation 100
iy. Note on Refraction, addressed to Professor ScHumMACHER . . 103
- General Results of Observations on the Dipping Needle. By
wv. Scopessyy Juni Baqi). swans dl anes Doth 2 wilfay 104
vi. Elements of the Comet of 1823-4, By various Computers . . 104
Xi. © © ° © AwALYsts oF ScrentiFic Books.
i. Sur les Ichthyolites ou Poissons Fossiles. Par M. Blainyille,
Article extrait.du. Noveau Dictionnaire d'Histoire Naturelle . . ~» 105
ii. Philosophical Transactions of the Royal Society of London, for
the Year 2gBP'82< IORI AES GW PEAY IORONY Wer wg lye ( 182
iii, Letter to the Editor from Dr. William Henry . . . . © . 131
XIII. Progress or Foreign ScieNcR . . « 6 we ow o + 135
XIV: MISCELLANEOUS INTELLIGENCE.
I, MgcHaANIcaL SciENCE.

1, Remarks on Tron-Wire Suspension Bridges. 2. Test for the
Action of Frost on Building Materials, by M. P. Brard. 3. On the
strength of Cast Iron, and other Metals. 4. On the Capillary Action
of Fissures, &c. 5. Sound produced by opening a Subterraneous

147

Gallery. 6. Nautical Bye-tube, 7. Leghorn Straw Plait 2...

If. CaraicaL Science.

1. On Fulminating Silver and Mercury. 2. On the unequal Dila~

tation of a Crystal in different directions, by heat, 3. Difference

CONTENTS. : lil”
Am i aaa PAGE
of Crystalline Forms of the same Substance. 4. Supposed Effect of
~ Magnetism on Crystallization. 4. Thermo-magnetisu. 5. Electro-—
maguetic Multipliers. 6. Plate Electrical Machines. 7. Improve-
ment of the Leyden Jar. §. Electricity on Separation of Parts. 9.
Electric Light. 10, Connexion of Phosphorescence with Electricity.
11. Phosphoresence of Acetate of Lime. 12. Preparation of Sul-
phurons Acid Gas. 13. Preparation of Sulpburetted Hydrogen. 14.
Preparation of Saturated Hydro-sulphuret of Potash or Soda, 15.
Preparation of Kermes Mineral. 16. Action of Sulphate on Iron.
17. Economical Preparation of pure Oxide of Nickel. 18. White
Copper. 19. Prussian Blac. 20, Crystallization’ of the Sub-car~
bonate of Potash. 21. Composition of Ancient Ruby Glass. 22. De-
tection of Arsenic in cases of Poisoning. 23. Ou the Detection of
Acetate Morphia in cases of Poisoning. 24. Test for Morphia. 25.
Process for obtaining Strychnia. 26. Volatility of Salts of Strychnia.
27. Acid Tartaric Sulphate of Potash. 28. Pyroligneous Ether, or
Pyroxilic Spirit. 29. Cafeine. 30. Conversion of Gailic Acid into
Ulin, 31. An Aécount of an Electrical Arrangement produced
with different Charcoals, and one conducting Fluid. . i ‘ . 158

Ill. Narurat Hisrory.

1. Vegetation at different Heights. 2. Irritability of Plants. 3.
Notice of an undescribed Lava which attacks and devours Snails. 4.
Hatching Fish. 5. Natural changes in Carrara Marble. 6. Note
on the existenee of a Nitrate anda Salt of Potash in Cheltenham
Water. 7. [odine in Mineral Waters, &c. $8. New Vesuvian Mine-
rals. 9. Products of combustion of certain Coal Strata. 10. Ad-
vancement of the Ground. 11. Existence of Free Muriatic Acid in
the Stomach, 12. Usé of Sulphate of Copperin Croup. . . Wa

On the Recurrence of the Smallest Light of the Variable Star Algol,
By W. M, Moseley, Esq. p Puke ‘ ' * oe 184

XV. Meterologieal Diary beet Aten Re ed) Gerrg «AQT

TO OUR READERS AND CORRESPONDENTS.

We are much obliged by Cantab’s letter, and will look more sharply into
those matters in future.

At page 345, line 12, of our last volume, for “ invariably,” vad ** in=
versely.” Hy 8

** An old Subscriber,” who accuses us of “ puffing,” had better not
stir the subject of his letter, least we should communicate information
which might be very disagreeable to some of the gentlemen whose cause
we presume he intends to advocate. No person or thing has ever been
puffed in this Journal.

The suggestions of ‘* Medicus” respecting the New Pharmacopeia,
shall be attended to.

Sir George Mackenzie's paper has duly reached us ; we regret that want
of room obliges us to postpone its publication.

The article on the Mechanic's Institution is too long for insertion.
We are sorry again to postpone our Correspondent y- A.
"The letter dated ‘* Glasgow, March 1,” shall have due consideration.

Among Miscellaneous Intelligence our readers will find much that
should have been placed under the head of Foreign Science.

We have received many communications and inquiries respecting the
Royal Institution, and feel much obliged for the facts which several of them
contain. The Visiter's Report will shortly be laid before the Members,
and will probably include the information sought for by some of our Cor-
respondents ; if not, they shall be replied to in our next.

The observations of F. R. S,, and those contained in-a letter dated
‘«* Kensington,” and in another signed ‘ Amicus Justitie,” are extrerhely
pertinent and judicious, but we feel disinclined to enter into the subjects
they touch upon if we can possibly avoid it.

‘The parcel from Manchester has just arrived. (March 29.)

Preparing for Publication, in 1 Vol. Svo.,
A MANUAL OF PHARMACY. By W. T. Branoz, F.R.S, &c.

CONTENTS

OF

THE QUARTERLY JOURNAL,
No. XXXIV.

ART. PAGE
I. On the Horary Oscillations of the Barometer. By J. Freperic
DET BES skalmoeinitel Secs watnemiepye) ih ed: mrcknd SO

II. On the Alterations of Rate produced in Chronometers by the in-
fluence of Magnetism. By Grorce Harvey, Esq., F.R.S.E., &e. 197

III. On Indistinctness of Vision caused by the presence of False
Light in Optical Instruments, and on its Remedies. By C. R.
Gorinc, M.D. (Continued from p. 28.) . . . . . . - 202

1V. Hints on the possibility of changing the Residence of certain
Fishes from salt water to fresh. By 1. Mac Cuxuocn, M.D., 4
NE Rete el kee tes ere ys set sy) oe UD

V. Mr. Cooper's Lamp Furnace, for the Analysis of Organic Bodies 232
VI. Description of a self-acting Blowpipe. By Mr. H.B. Lerson 236

VII. Astronomical Phenomena arranged in Order of Succession,
for the Months of July, August, and September, in the Year
1824. By James Souru, F.R.S. (Continued from Page 84) 238

VIII. On the Soundings in the British Channel. [To the Editor of
ihe’ Quarterly sournal| 9s. 2. se. < +. e -seue, es) ou 6 BHO

IX. Some particulars respecting the Ornithorhyochus Paradoxus.
PIO IE SOOT IRA Veh pa.) sina walang Ces! asthiaA Sad St se okies 240

X. Procerpines or rHE Royat SocreTy . .. +. 2 «© « « « 200
XI. Proceepincs or true RoyarlnstiruTion . ..... . 281
XII. Asrronomicat anv Navricat Coxrections. No. XVIII.

. i. Extracts relating tothe Theory of Tides 2. 1 ee + 295,

1 CONTENTS.

ART. PAGE
ii, An easy Method of computing the Time indicated by any

Number of Chronometers, with the given Time at a Station. By the

Rev. Fearon Fallows, M.A., F.R.S., Astronomer at the Cape of

GoodsHopesaiconts Mar eb SUBSE MOMENTA. ET Mn ot apa

iii, Easy Approximation to the difference of Latitude on a Sphe-
roid y.5 fret eGNS * WP eee ae a ee se ee

iv. Extract of a Memoir on the Theory of Magnetism, read at
the Academy of Sciences, 2 Feb. 1824. By M. Poisson . . . . 317

XIII. ANALYSIS OF ScrenTIFIc Books.

i. Meteorological Essays and Observations. By J. F. Daniell,
IBURAS.,, °" 3.\¥e00"s). ¢ ep ge deite hee ig ane is Otis Nc ps alles amas

ii. A translation of the Pharmacopeia of the the Royal College of
Physicians, 1824. With Notes and Illustrations. By Richard Phil-
lips, F.R.S., Lon. and Ed. &e, &e. epee ow oy se BAD

XIV. MIsceLLANEOUS INTELLIGENCE.
I. MecHANICAL AND GENERAL SCIENCE.

1. Adhesion of Nails in Wood. 2. Levels in London above the
highest Water-mark. 3. On the comparative Advantage of Coke
and Wood as Fuel. 4. Vicat on burning of Limestone or Chalk.

5. On the Application of Muriate of Lime asa Manure. 6. Pre-
paration of Caoutchouc. 7. Magnetic Intensity of a Chronometer.
8. Influence of Magnetism on the Rates of Chronometers. 9. On
the adaptation of a Compound Microscope to act as a Dynameter
for Telescopes. By C. R. Goring, M.D. : : 360

Il. Cuemican SciENCE.

i. On a Reciprocity of insulating and conducting Action
which the incandescent Platina of Davy exerts on the two Electri-
cities. 2. On the magnetic Action of strong electrical Currents on
different Bodies. 3, On Electro-motive Actions produced by the con-
tact of Metals and Liquids. By M. Becquerel. 4. Measurement of
the conductibility of Bodies for Electricity. 5. Distinctionof Positive
and Negative Electricity, 6. Electricity produced by the Congelation
of Water. 7. Hare’s Single Gold-leaf Electrometer. 8. Hare's Voltaic
Trough. 9. Dobereiner’s instantaneous Light Apparatus. 10, Test

CONTENTS. iii

ART. PAGE
of the Alteration of Solutions by contact with Air. 11. Odour of
Hydrogen Gas extraneous ; Inodorous Hydrogen Gas. 12. Inflam-
mation of sulphuretted Hydrogen by Nitric Acid. 13. Artificial
Chalybeate Water. 14. Mereurial Vapour iu the Barometer. 15.
Combustion of Iron by Sulphur. 16. Ammonia in Oxides of Iron.
17. Iodous Acid. 18. Preparation of pure Oxide of Uranium. 19,
Uranium Pyrophori. 20. Atomic or Proportional Weights. 21.
On the Acetates of Copper. By M. Vauquelin. 22. Dahline, or
Inuline, in the Jerusalem Artichoke. 23. New Vegeto alkali, Vio-
line. 24. Jalapine, or Jalapia. 25. MM. Leibeg and Gay-Lussac on
Fulminic Acid and Fulminates. 26. Supposed new Metal, Taschium
27. Liquefaction of Sulphurous Acid : : 369

Ill. Naturat History.

1. On the different Manners in which Bodies act on the Organs
of Taste. By M. Chevreul. 2. Action of Meconic Acid on the
Animal Economy. 3. On the ditferent Masses of Iron which have
been found on the Eastern Cordiliera of the Andes. By MM. de
Revero and Boussingault. 4. Natural Ice Caves. 5. Glacier of

Getros, Valley of Bagne. . . . . - 892

XVI. Meteorological Diary for the Months of March, iy and
May, 1824 : : : E . 398

Inpex : : : : . . 399

TO OUR READERS AND CORRESPONDENTS.

Several Papers remain on our hands, which, for reasons already com-
municated to the respective authors, we are obliged to decline publishing.
We shall be under the necessity of destroying these papers, unless they
are immediately applied for.

We regret that the Paper on the Analysis of the Holy-well Water is
too long for insertion.

F Mr. Stevenson s Paper is declined in consequence of the number of
engravings requisite for its illustration. The drawings shall be taken
care of.

We suspect that our voluminous Correspondent upon the subject of
London Bridge is not quite disinterested, andif he will favour us with
his address, he shall be convinced that we have not neglected the ample
consideration of his communications,

The request of E. A. has been made known in the proper quarter.

Mr. Bigsby’s Paper has reached us, and will appear in our next Num-
ber.

We never advocated the Repeal of the Salt-Tax, and cannot therefore
conscientiously insert the Letter of our Correspondent at Liverpool.

Mr. Walsh’s Letter reached us too jate for insertion.

We cannot meddle in the matter alluded to by ous Correspondent at
Edinburgh, who nevertheless has our thanks.

Preparing for Publication,
A MANUAL OF PHARMACY.

BY
W. T. Branbg, F.R.S., Ke.

THE

‘QUARTERLY JOURNAL,

April, 1824.

Art. I. On some Phenomena relating to the Formation

of Dew on Metallic Surfaces. By George Harvey,
M. G..S.,.5:¢;. de.

[Communicated by the Author.]

It is a curious fact, mentioned by Dr. Wells, in his valuable
Essay on Dew, that if a metallic substance be closely attached to
‘a body of some thickness, which attracts dew powerfully, the ten-
‘dency of the metal to promote the formation of moisture on its sur-
face, instead of being increased from the circumstance, is dimi-
nished, provided the metal covers the whole of the upper surface
‘of the body to which it is attached*. This principle he illustrated
by the following experiment: Two pieces of very light wood, each
four inches long, a third of an inch wide, and one tenth of an inch
thick, were joined in the form of a cross ; and to one of its sides
the non-metallic surface of a square piece of gilt paper was at=
tached, by means of mucilage. On exposing the metallic surface
‘on a dewy night, by suspending it ina horizontal position, about six
inches above the ground, he found after a few hours, that the parts
of the metallic paper, not in contact with the wood, had minute
drops of dew on their surfaces, while those in contact with the
‘cross, were perfectly dry.

In repeating this experiment, I have employed gold and silver

* Wells on Dew, page 22, second edition,

Vou. XVII. B

2 Mr. Harvey on the Formation

metallic paper, attached to frames of various forms; and by pro-
secuting the subject under different circumstances of the atmo-
sphere, I have met with some interesting and beautiful phenomena,
which seem to merit a particular description.

The metallic squares were sometimes suspended. a few inches
above the ground, and at other times placed on surfaces of glass,
or on the recently-mowed herbage. The particular situation of
each will however be noticed, as the different experiments are
described.

In endeavouring to trace phenomena relating to the deposition
of dew on the surfaces of polished metals, some perseverance is
necessary ; as it is but seldom that the circumstances of tempera-
ture and moisture are such, as to permit its ready formation. It
would appear, that not only the depression of temperature, and the
presence of moisture in the lowest atmospheric stratum, must be
considerable ; but that the superficial dimensions of the metal have
also an influence on the formation of moisture on it. ‘The dif-
ference between glass and polished metals in this particular is sin-
gularly remarkable. A small vitreous surface, when presented to
a clear and tranquil sky, has its surface as readily covered with
moisture as one of larger dimensions ; but in the case of metals of
the same kind, of polished tin for example, a large metallic plate
is sometimes more readily dewed than a small one ; whereas, under
other circumstances, one of a small area is covered with a copious
deposition of moisture, whilst a large one will preserve, during the
whole night, a bright and unsullied surface*. I have thought it
proper to introduce these remarks, in order to apprize the young
inquirer of the disappointment to which he will be frequently liable,
when prosecuting this interesting subject with relation to polished
metals.

Whenever the squares of silver paper were exposed for the pur=

* ‘A large metallic plate, lying on grass, resists the formation of dew more
powerfully than a very small one similarly situated. If a large and a very
small plate be suspended horizontally, at the same height in the air, the small
plate will resist the formation of dew more powerfully than the large.”’—
Wexts on Dew, page 22; second edition.

of Dew on Metallic Surfaces. 3

pose of receiving dew, it was remarked, that the first formation of
moisture took place at the corners of the triangular portions of the
metallic paper, not in contact with the wood; the particles beng
exceedingly minute, and requiring the aid of a magnifying glass to
discover them. As the radiation of the metallic surfaces was pro-
moted by the influence of the clear nocturnal sky, those particles of
moisture gradually increased both in number and size ; while other
minute drops began at the same time to be deposited on the edges
of the square; so that in the course of three hours, the metallic sur-
face had assumed the appearance represented in fig. 1, Plate I. the
shaded parts denoting the particles of dew, and the dotted lines
the position of the cross to which the metallic paper was attached.
After midnight, the farther deposition of moisture appears to have
been suspended; as at half an hour before sunrise, the appearance
of the metal was nearly the same as when the last observation was
made.
~ It was most interesting to observe, during the progressive depo-
Sition of the moisture, that the particles were disposed in triangular
forms, similar to the right-angled triangles, into which the metallic
paper was divided, by its contact with the cross ; and this was the
case even when the triangles, from their minuteness, might be es-
teemed of an almost elementary kind. And at the last observation,
when the greatest quantity of dew for the night had been depo-
sited, the triangular figures were perfectly well defined, their hypo-
thenuses being bounded by the edges of the metallic surface, and
their several bases and perpendiculars, respectively parallel to the
arms of the cross. . So also the gradual accumulation of moisture
in the small segments, whose chords coincided with the edges of
the metal, was marked by the same uniform and progressive cha
racter; the particles, during their increase in number and magni-
tude, preserving a beautiful curvilineal contour to the figures which
they formed. The parts of the paper in contact with the cross, had
no dewy particles on them ; their junction with the wood appearing
effectually to prevent the formation of moisture ; thus confirming
the observation of Dr. WELLs.
On another night, favourable to the copious formation of dew,
B 2

4 Mr. Harvey on the formation

the moisture was not confined to the small triangular and curvili-
neal spaces alluded to in the preceding experiment, but was dif-
fused over the whole surface, excepting the parts in contact with
the wood. The metallic surface presented therefore a dry portion
with well defined borders, in the form of the algebraic sign plus ;
and four triangles of dew, formed of particles, beautifully distinct,
but undergoing a minute diminution in size, from the edges of the
paper to the vertices of the triangles, as represented in fig. 2, To
contemplate these triangular formations of dew to advantage, it
was necessary to place the eye in a situation to receive the impres-
sion of the reflected light. In such a position the forms of the tri-
angles were viewed to great advantage ; the innumerable atoms of
dew presenting a pleasing contrast to the unsullied figure of the
cross.

On the same night a similar surface of gold metallic paper, simi-
larly circumstanced, presented an appearance as in fig. 3, in some
degree analagous to that represented for the silver paper im fig. 1.
The moisture seemed however destitute of that uniformity which
characterized the particles formed in the last-mentioned diagram,
although some slight approach to it might be traced, in the forma-
tion of the irregular patches of dew, in the angular portions of the
figure.

On the following night, portions of silvered paper attached to
triangular and square frames, as denoted by figures 4 and 5, were
presented to the nocturnal sky. In the former, the beautifully
minute particles of dew were confined to the equilateral triangular
surface, not in contact with the frame; the particles however
seeming to preserve an uniformity of magnitude over the whole
surface. To the middle of the non-metallic surface of fig. 5, a cir-
cular piece of wood was attached, of the same thickness as the
frame ; and during the abundant deposition of dew which took
place in the course of the night, the moisture was strictly confined
to the parts of the metallic paper, not in contact with the wood ;
the small circular portion, although surrounded as it were with an
atmosphere of moisture, presenting as effectual a -barrier to its
formation as the external frame.

of Dew on Metallic Surfaces. ; 3

During the prosecution of these experiments, J have had fre-
quent opportunities of remarking that silver metallic paper per-
mits dew to be deposited earlier, and in greater abundance on its
surface, than gold. arly in the month of April, at nine p. m.,
a large pane of glass was placed on the green herbage, and on it
the squares of gold and silver paper attached to their respective
crosses. The clear and transparent sky, joined to the perfectly
tranquil state of the atmosphere, indicated the possibility of a co-
pious deposition of dew. At six the next morning the grass exhi-
bited the appearance of a thick hoar frost, and the moisture which
had been formed on the upper and under sides of the glass during
the night, presented coats of transparent ice. On referring to the
squares of metallic paper, that of gold was found removed from the
glass on which it had been placed the preceding evening, to the
distance of six feet; its change of situation having been probably
produced by the force of some breeze during the night. ‘The me-
tallic side was in contact with the grass, and on taking it up it
presented four beautiful triangles, completely covered with innu-
merable particles of frozen dew. Those parts of the metal which
had their inferior surfaces in contact with the wood, exhibited the
perfect and well defined form of the cross, represented in fig. 6, The
appearance of the crystalline triangles, when contrasted with the
golden surface ef the cross, was extremely beautiful ; and it was
remarked, that as the gradually increased warmth of the morning
dissolved the crystals of dew, the moisture was still confined to the
same triangular surfaces: thus preserving completely the form of
the cross. Minute crystalline atoms were also perceptible on the
non-metallic side of the paper, and which, likewise dissolving, had
a sensible effect on the rigidity of the paper. On examining the
silver square which had preserved its situation on the glass, its
metallic surface was found without the appearance of moisture,
under any form, on its surface.

A hasty consideration of this phenomenon might lead us to infer,
that dew is more readily deposited on gold than on silver, con~
trary to what has been before remarked, as the result of extended

6 Mr. Harvey on the Formation

observations ; but a farther investigation of the anomaly in question
may lead to a satisfactory explanation of its cause. eee

The appearance of the heavens at the time the metallic sure
faces were placed in the meadow for observation, indicated, as be-
fore remarked, the probability of a copious deposition of dew,
during the night, and that a considerable quantity was deposited,
the hoar-frost in the morning clearly proved. The temperature,
and the hygrometric state of the air, were also, from other collate-
ral circumstances, to be regarded as highly favourable to the for-
mation of dew on metallic bodies; and that a breeze must have
existed for some time during the night, sufficiently powerful, at
least, to remove the metallic square, together with its attached
cross, to the distance of several feet, is likewise apparent. These
circumstances will account for the anomaly in question, *

In the first place, dew was most probably deposited during the
former part of the night, in a sufficiently copious degree, to cover
the four triangles on each of the metallic surfaces. This deposition
may be presumed to have taken place before the temperature of
the lowest stratum of air, in contact with those surfaces, was de-
pressed to that of the freezing point. The breeze removed the
golden square, and left its metallic surface in contact with the short
herbage, the temperature of which had been previously re=
duced to 32°. This temperature necessarily caused the particles
of dew already deposited on the triangular surfaces to crys-
tallize ; and left the cross with its lustre undiminished. The same
wind dissipated the moisture that had been deposited on the silver
surface; for it has been remarked by Dr. Wells*, that ‘the dew
which has formed upon a metal will often disappear, while other
substances in their neighbourhood remain wet.” The breeze indeed
may have continued the remainder of the night, and prevented any
new formation of dew onthe silvery surface; but, at the same
time, permitted moisture to be deposited on the non-metallic sur-
face of the golden square ; because white paper has been placed by

* Page Ql, Essay on Dew, hy De. Weta, second edition,

of Dew on Metallic Surfaces. Y

the last-mentioned philosopher among the substances that are even
more productive of cold than wool*. Or it is possible that the
breeze may have subsided, and the circumstances of temperature
become such as to have allowed the deposition of dew on the
paper, but not of its re-formation on the silver.

Dr. Wells has also remarked +, that when dew forms upon me-
tals, it ““ commonly sullies only the lustre of their surface ; and that
even when it is sufficiently abundant to gather into drops, they are
almost always small and distinct.” This observation, however, re-
quires some limitation ; since, on nights that have been more than
usually cold, and when the quantity of moisture in the air has been
abundant, I have observed the dewy particles deposited on metals
to attain a considerable magnitude ; and examples have even oc-
curred of polished tin surfaces being completely covered with thin
sheets of water, the result of the junction of the innumerable minute
particles deposited on them.

On one night, equal squares (their linear edges being one inch
and half) of lead, zinc, brass, copper, and tin, were laid on a
large plate of glass, and presented to the influence of a clear sky.
At sunrise the next morning, the particles of dew on the different
surfaces were found of variable magnitudes ; those on the lead being
the largest, and of the size represented in fig. 7. Those on the zine
were next in magnitude, as denoted in fig. 8; and the particles on
the brass were still smaller, but much more numerous, as in fig. 9.
The copper and tin, particularly the latter, seemed only to have had
the lustre of their surfaces just dimmed, by the abundant moisture
of the air. Lead, therefore, was at one extreme of the series, and
tin at the other ; brass holding a middle rank between the two.

- This relation, however, between the particles on lead and brass,
was inverted on another night, when equal squares were laid on
the recently cut herbage, the particles on the brass being of the size
represented in fig. 10, and those on the lead as denoted in fig. 11,
As the plates of metal were the same in both cases, it is reasonable

* Page 21, Essay on Dew, by Dy, Wet1s, second edition,
} Page 21, second edition,

8 Mr. Harvey on the Formation

to infer that the opposite results, observed were produced by the
substances on which they were respectively placed. A slight trace
of moisture was perceptible on the zinc, but not the least degree
on the copper and tin. »

An example of the slowness with which polished tin permits
moisture to be deposited on it, occurred when a concave mirror,
formed of polished block tin, was employed as an /thrioscope, on
the plan first suggested by Dr. Wollaston. The focus of the in-
strument, at the time the experiment was performed, was 20 inches
above the ground. The night was tranquil, and dew was copiously
deposited on glass, a few minutes after it was presented to the
chilling influence of the transparent sky. Atnine, vr. M. the ther-
mometer in the focus of the Athrioscope indicated a temperature
of 46°; the herbage being at the same time 44° ; and the air, seven
feet above the ground, 494°. Observations, connected with some
other phenomena, were made every half hour; but no trace of
moisture was perceptible on the metallic surface, till two a. M.,
when it appeared slightly dimmed, although other substances had
gained considerable increments of dew in the same time ; masses
of wool, for example, having increased in weight from twelve grains
to thirty. At the same moment, the focal thermometer indicated a
temperature of 424°; that on the grass, 39°; and that elevated in
the air, 45°. In five hours, therefore, the cold of the upper sky
only underwent a change of 33°; whereas the grass lost by radia-
tion in the same time 5°; and the eleyated stratum of air diminished
its temperature 45°. From two o’clock to three, the thermometer
remained stationary, but the moisture had sensibly increased on
the surface of the Athrioscope, and increments amounting to se-
veral grains, were likewise found on other substances ; a proof,
that if the general temperature remains stationary, after the tempe-
rature of a body is sufficiently lowered to permit the formation of
dew on its surface, the farther deposition of moisture is not pre-
vented. At four a.m. the whole metallic surface was covered with
visible drops, the temperature, at the same moment (just before
sunrise), indicating the maximum of cold, the focal thermometer

of Dew on Meiailic Surfaces. 9

being at 40°; that on the grass, 37°; and that elevated seven feet
above the ground, 414°. It is worthy of remark, that two plain
sheets of polished tin, placed horizontally on the herbage, had not
the slightest trace of moisture on them.

On another night, however, when there was every prospect of an
abundant deposition of dew, the influence of the grass in promoting
its formation on metals, was clearly shown. At nine p. m. two plates
of polished tin, one fourteen inches by ten, and the other six by
two, were laid on very short grass. Another plate of the same di-
mensions as the former was placed gently on the long grass. Its
weight necessarily compressed the herbage on which it rested, so
that the polished surface was surrounded on all sides by grass,
reaching twelve inches above it. In fig. 15 the long grass is repre-
sented on two opposite sides of the tin M N, together with the com-
pressed herbage below it. At eighteen inches above the ground,
or two inches above the average height of the grass, a similar
plate, O P, was placed on slender props. The temperature of the
grass at the moment the plates were exposed was 60°, and of the
air 65°; being a difference of 5° in the small space of three feet.
At five the next morning, a great quantity of dew was formed on
the grass. A register thermometer on the short herbage, indicated
the maximum cold to have been 52°, and of the air, at the elevation
before mentioned, 60°. ‘The difference between these maximum
depressions of temperature was, therefore, by no means considera-
ble; and the copious deposition of dew observed was to be regarded
rather as the result of the abundance of moisture in the atmo-
sphere, than as a consequence of great difference of temperature.

The metals presented the following particulars for observation.
The plates resting on the short herbage had a few scattered patches
of dew on their upper surfaces, but nothing like a regular and uni-
form deposition, The plate M N, surrounded by the long grass,
had its superior surface completely covered with minute but distinct
particles of moisture ; but the plate O P, elevated above the grass,
was perfectly dry. This difference in the results must be regarded
as arising from the different conditions, under which the plates
were situated, Tee latter surface, it will appear, had not its tem-

10 Mr. Harvey on the Formation

perature depressed below that of the stratum of air reposing on it,
during the night; but the former must have been considerably
colder than the column of air hovering above it. The cooling
power of the grass surrounding the plate MN, and on which it
also rested, must have necessarily extended its influence to the me-
tal; and by lowering its temperature considerably, have occasioned
the copious deposition observed. The upper plate not being in
contact with the grass, permitted the air to pass freely on each
side of it; and being itself a bad radiator, attained no condition
during the night favourable to the deposition of dew. With re-
spect to the formation of dew being less abundant on the plates
resting on the short herbage, than on that surrounded with the long
grass, it may, in one point of view, be regarded as a consequence
of the ‘curious fact observed by Mr. Six, that the temperature of
short grass is always greater than that of long grass. The state
of the herbage has always a considerable influence on the quantity
of dew deposited, and the greater the body it presents, the more
abundant it is likely will be the formation. That the quuntity of
herbage has a considerable effect, may be inferred from the expe-
riment, that when one mass of wool was placed on short herbage,
and another of equal size and weight on the summit of a mass of
recently cut grass, fifty inches above the ground, the moisture
gained by the former during the night, was only fifteen grains,
whereas the increment to the latter was twenty-three.

In consequence of the plate O P having had its surface exposed
to the entire canopy of the sky, but the view from the plate M N
being confined to a comparatively small circular space, in the zenith
of observation, it might be inferred from a principle adopted by
Dr. Wells*, that the former would have gained more moisture than
the latter. But the maxim of this ingenious philosopher is evidently
limited to the consideration, that the bodies are in other respects
similarly circumstanced. For instance, in one of the experiments

* Essay on Dew, page 14, second edition. The principle here alluded to ig
the following; * Whatever diminishes the view of the sky, as seen from the
exposed body, accasions the quantity of dew which is formed upon it, to be fega
than would have occurred if the exposure to the sky had heen complete,”

of Dew on Metallic Surfaces. I!

instituted by Dr. Wells, to illustrate the principle in question, by
bending a sheet of pasteboard into the form of the roof of a house,
and placing it with its ridge uppermost, and ends open, over a mass
of ten grains of wool laid on the grass ; and at the same time placing
another equal mass on the herbage, fully exposed to the sky, the
former gained, during the night, an increment of only two grains,
whereas the latter gained sixteen. In this experiment, the two
masses were placed under the same circumstances, so far as con-
tact with the grass was coucerned; but in the case relative to the
plates of tin, one was not only in contact with the herbage, but also
surrounded by it; whereas the other was completely detached.
The gradual manner in which dew is deposited on the metallic
side of gilded glass was pleasingly exemplified on another occasion.
The parallelogram of glass was six inches by four, as represented
in fig. 14. It was first exposed to the atmosphere with its metallic
side uppermost, at half-past six, rp. m., being about three quarters
of an hour after sunset. The atmosphere was clear, and highly
charged with moisture ; and dew had formed on glass in a shady
place, three quarters of an hour before the departure of the solar
orb. A mild and gentle breeze prevailed also at the same time. No
perceptible change took place in the metallic surface until eight,
when minute particles of dew were visible at A, the leeward end.
From the last-mentioned hour to ten, the moisture gradually in-
creased from A to the middle part of the surface ; and distinct drops
were likewise deposited at D, B, E,C. As the particles increased
in size round the three edges, other minute drops were successively
deposited, more distant from them ; and it was observed, that they
accumulated with most rapidity at the leeward sides A and C. At
eleyen, Pp. M., when the sketch represented in the figure was made,
an oval portion of the metallic surface was found entirely free from
moisture. The same figure was also perfectly visible at midnight,
when the drops at A had increased to at least an eighth of an inch
in diametey; those at C being rather less, The particles at the
corners D and E also preserved their superiority in size above those

at B,

12 Mr. Harvey on the Formation of Dew.

The difference in the appearance of dew, when deposited on tin
and on glass, is sufficiently remarkable to arrest attention, not only
when the moisture remains uncrystallized, but also when it is frozen.
In an example that occurred of the latter case, a decrease in the
magnitudes of the frozen particles could be traced from its edge to
the dry and unfrozen margin surrounding a parcel of wool, placed
on the middle of the plate, as represented in fig. 13: the appear-
ance of the frozen atoms partaking, in some degree, of the lustre of
the tin. The parcel of wool, in the interval from nine P. m. to mid-
night, gained four grains of moisture ; and from the last mentioned
hour, to six the next morning, thirty-two grains ; thus gaining, in a
double time, an eight fold quantity of moisture. The wool was frozen
to the tin; and when the rays of the sun fell on the metallic surface, the
crystalline particles became detached from it, and were readily col-
lected together. The dew deposited on the glass presented an irregu-
lar fibrous appearance, its colour partaking of the greenish hue of
the crystal. The icy particles on the tin were first deposited as dew,
and frozen before they had collected in sufficient numbers to run
into each other, and form an uniform crystalline surface. But the
dew on the glass being formed at an earlier period of the night, a
sufficient quantity was deposited to cause the particles to mingle
with each other, and thus to present to the action of the freezing tem-
perature a wide spread surface of water. The unequal action of the
glass, combined with the law which regulates the crystallization of
water, communicated to the frozen surface of dew, the fibrous and
irregular character represented in fig. 12. Soon after the solar rays
had impinged on the glass, filaments of ice were detached from
both its surfaces, that from the upper side being much the thickest.

Plymouth, December 12, 1823.

13

Arr. Il. Description of Two New and Remarkable Fresh

Water Shells: Melania setosa and Unio gigas. By
William Swainson, Esq., F.R.S., L.S., M.W.S., Se.
[Communicated by the Autkor.]
THE attention of several conchologists has been excited by a new

and most extraordinary fluviatile shell, belonging to the genus

\

Melania, recently brought from the Mauritius. Having been fa-
voured with its examination, I now lay before the public the follow-
ing description of the shell, drawn up from the only specimen
which its discoverer, Mr. Warwick, was able to procure, after
diligent and often repeated searches in the same locality. I take

this opportunity also of recording the characters of another fresh-

water shell of gigantic dimensions, equally unknown and interest-
ing to naturalists.
Mevania. Lam: Cuy.

Specific character.
M. testa ovata, ventricosa, spinis tubularibus seta bina porrecta

‘basi connexa emittentibus coronata. Shell ovate, ventricose, co-
Tonated by tubular spines, each sheathing the ‘base of two pro-

truded horny bristles,
DeEscriprion.
Length, one inch two tenths, of which the spire occupies very ©
nearly one half. In habit the shell resembles Melania amarula,
(Helix amarula, Lin.) but the basal volution is more ventricose, the
spire more conic, and the tip acute; it is also much thinner, and
may be termed subdiaphanous; the whole shell is covered by an
olive brown epidermis; the spiral volutions are angulated, and
marked by from three to four transverse elevated striz ; the basal
volution is without any indication of plaits, but is slightly im-
pressed by narrow, transverse grooves, which are wide apart; these
are crossed by very delicate and close-set longitudinal strie; but
whether these last are only external and belong alone to the epi-
dermis, could not be ascertained without injury to the specimen,
The most extraordinary characteristic of this shell, I shall now
proceed to detail. On the upper part (or shoulder as it is some-
times called,) of the body whorl, is a row of coronated spines,

14 Mr. Swainson’s Description of

perfectly tubular; these spines are very thin, and are placed parallel
with and very near to the aperture; their summits are obtuse and
their length variable, probably owing to some having been injared
through their great delicacy; the longest measured nearly one-
eighth of an inch; from the summit of each spine emerges two
stiff erect acute bristles; closely adhering together, and projecting
about two-tenths of an inch. The colour of these bristles is black,
their surface polished, and their substance horny. They likewise
possess some degree of elasticity, being easily bent by a slight
pressure applied laterally ; although I doubt whether they would
have sustained such pressure had it been applied horizontally.
These bristles it will be perceived, are completely sheathed at their
base by the tubular spines, but these latter are so thin that the
lower part of the bristles are distinctly seen through them; rooted,
as it were, in the substance {of the shell. I know not, positively,
whether each spine contains ¢wo distinct bristles; or only one,
forked or divided at about half its length, as this fact could only
be ascertained by removing one of the spines, and tracing how far
the division extended; but that portion which forms the lower
half (and is enclosed within the spine) is so thick, as to favour the
supposition of their being in pairs. These spines are continued
round the middle of each volution of the spire to its apex ; but they
are more remote, and the bristles much shorter, than those on the
body whorl; sometimes, indeed they hardly project beyond the
spines. The direction of the whole is slightly incurved. The
aperture is pale; and, at the top of the outer-lip, is an indented
sinus similar to that seen in M. amarula, Lam.

Ob. 1. The extraordinary appearance of bristles protruding from
the spines of a shell, a formation altogether unprecedented amongst
this class of animals, might naturally excite, in some minds, a sus-
picion that it was an ingenious deception. But this idea, I think
will be abandoned, when the peculiar construction of the spines
are well considered. In the genus voluta, we have many instances
of shells being crowned with thin, vaulted spines, but no example
can be produced, of such coronated spines being tubular; or com-
pletely closed in their circumference, and pervious only at their

two New Freshwater Shells. 15

summits. Now it is obvious, that this peculiar form, is of all
others the best adapted to strengthen and protect the elastic bris~
tles which they enclose: both appendages, therefore, are in unison
with each other, and leave not a doubt in my mind, (setting aside
the personal testimony of its discoverer) that the whole shell is in
a perfectly natural state.

It is difficult to conjecture in what way the formation of the
shell accords with the economy of its inhabitant. We know that
testaceous mollusca, are the food of several kinds of fish, both ma-
rine and fresh-water; may not these bristles be intended by nature
to defend the animal from such enemies? they would certainly be
very repulsive to the lips of any fish; and in all probability would
penetrate, as deep as possible into the skin. The weapons of pro-
tection or of defence with which nature has furnished different
tribes of animals, are as various as they are wonderful. In the
testaceous mollusca, they are confined alone to the shelly covering
of the animal, who, as long as his castle is armed and entire, with-
draws into its walls, secures the entrance, and remains passively
secure.

0b. 2. Since the above was written, Mr. Broderip informs me,
another specimen of this shell has come into his possession : “care-
fully cleared, and every vestige of bristle removed, the hollow co-
ronations remain.”

Unio GiGas.
Specific character.

U. testa ovato-oblonga, depress4, anticé alata et sulcis obliquis,
divaricatis subradiata; posticé brevissima; dente laterali (utri-
usque valve) solitario; umbonibus brevibus, retusis.

Shell ovate-oblong, depressed anterior side winged and marked
by oblique grooves in different directions ; pdsterior side very short;
lateral teeth, one in each valve; umbones small, retuse.

Description.

This is truly a gigantic shell; far exceeding in size any other
yet discovered as inhabiting the fresh-water, and presenting cha-
racters which leave no doubt that it has hitherto remained unknown
to all conchological writers. Its extreme length is rather more

16 Mr. Swainson’s Description of

than eight inches and a half; and its greatest breadth (from the
ligamental to the basal margin,) five inches three-quarters.

Its form is a broad oblong-oval; obtuse at both extremities; the
anterior of which is broadest and sinuated, aud the posterior
rounded, and so very short as to project only three quarters of an
inch beyond the outer side of the cardinal teeth. The whole shell
is remarkably flat but very thick in substance; and the umbones,
which are unusually small have scarcely any convexity; the liga-
mental margin is dilated, winged, and forming in its dilation nearly
two equal sides; the horny part of the ligament itself, (with the in-
ternal plate that supports it,) extends half way between the umbo
and the extremity of the wing; the exterior colour of the epidermis,
is dark brown, but the umbones (in this specimen) are decorticated
for a considerable space around them. The sculpture of the an-
terior part of the shell is very peculiar; it consists of four series of
short oblique grooves, or of indented wrinkles, three of which are
arranged in a direction with the umbonial slope *, the other is trans-
verse; the first of these series consists in parallel grooves which
cross the wing obliquely from left to right. The next is a range of
broad and sinuated indentations, wide apart and having the same
inclination as the former; the third range occupies the umbonial
slope, and is formed by narrow sulcated grooves, placed nearly in
a horizontal direction, and diminishing in length as they approach
the umbones. The fourth and last consists of several transverse
erooves situated near the basal margin, and the whole presents
an appearance as if the shell had been indented, .in various di-
rections, by some blunt instrument.

The inside is pearly, white, tinged with flesh-coloured purple,
and stained (as is frequently the case, in fluviatile bivalves) with
olivaceous yellow spots; in a perfect state of the shell the colours,
probably, would be more brilliant.

The cardinal teeth are strong; deeply and irregularly striated
and are obliquely transverse; in the right valve are two, and in
the left valve, one; in each valve there is only one lateral tooth, a
very unusual and discriminative character for the species; this

*See Zoologi Ilust.

two New Freshwater Shells. 17

tooth is very thick, minutely crenated, and is double the length of
the ligamental plate, which latter is much elevated, broad, and
terminates abruptly in a sinus extending to the point of the wing :
adjoining the cardinal teeth are four deep muscular impressions,
one of which is very large, and two of the others very small; the
anterior impressions are slight and present nothing peculiar.

Ob. Two odd valves of this unique shell came into the possese
sion of Mr. G. Humfrey, A. L.S., many years ago; and were
sold with part of this gentleman’s collection last spring; the shell
then passed into the hands of Mr. Mawe; Mr. H. was informed it
came from the river Oronokoo; this I think a very probable lo-
ceality, for it has all the characteristics of an American species; its
massy substance and uncommon size seems, moreover, in unison
with the force and rapidity of such a vast river. I am not well
satisfied as to the exact form of the dilated process on the anterior
side; as in both these valves the edges had been injured and re=
paired: in the perfect shell this part probably may be more di-
lated, and may terminate in a form somewhat different from that
which I have described.

Warwick, 1824.

Arr. II. On Indistinctness of Vision, caused by the pre-
sence of False Light in Optical Instruments ; and on tts
Remedies, by C. R. Goring, M. D.

(Communicated by the Author,]
Opricat instruments in general have within the last century been
brought to so high a degree of perfection, that it may almost be
doubted if there remain any real improvement to be made in them ;
nevertheless, it has appeared to me, that in the humble depart-
ment of their construction which provides against the admission
of false light, there is still left some capability of a farther ad-
vancement towards perfection, which may be effected with advan-
tage, to the performance of astronomical refracting telescopes,
Newtonian reflectors, and compound microscopes.—As it is neces =

sary to understand the nature of an evil before we can cure it, as
Vou. XVII. C

18 Dr. Goring on False Light

well as to feel the utility of removing it, I shall here give a slight
account of the indistinctness occasioned by fog, (as it is technically
termed) to which I propose to apply a remedy. Thus, when we
look through a telescope admitting false light at a printed bill, the
plate of a clock, or other such object, especially if the day is
clear, and the sun shines on it, we find, (however perfect the in-
strument may be in other respects,) the letters or figures do not
appear nearly so black and sharp, as they will when viewed by the
naked eye under the same angle, but rather of a brownish colour;
in other words, the effect upon the eye, is similar to that of looking
through a mist, or through glasses dimmed by moisture ; in short,
what an ordinary observer would express by saying, the instrument
, did not shew objects clear and distinct*. Now, on examining the
pencil of rays proceeding from the eye-piece of such a telescope,
with a magnifier, it will (supposing no other source of indistinct-
ness exists,) be found surrounded by a variety of foreign rays,
forming different halyos about it, instead of appearing like a span-
gle on a piece of black cloth, which it will do, when all the false
light is stifled, as in Gregorian and Cassagrain reflectors by their
eye-hole, and in refractors with erecting eye-pieces, which have
a stop between the two bottom glasses, producing the same effect,
by suffering nothing but the true and genuine pencil of light, from
the object glass or metal, to teach the retina, Indeed, in these in-
“struments the quantity of spurious rays would be so great, as ab-
solutely to preclude any thing like distinct vision, without the
stops and eye-holes in question, In those to which I propose to
apply an equivalent contrivance for extinguishing fog, though there
may not be the same imperious necessity for its application; still
I think the advantage to be gained by the improvement, is not to
be despised, but will rather be admitted to be highly useful and
appropriate, as placing optical instruments one step nearer perfec-
tion than they would otherwise be, by producing the maximum of
distinctness and clearness of vision, of which they can be rendered
susceptible, consistently with their excellence in other respects.—

» * All cbjects are of course equally affected by the fog, but it is more striking
in those I have designated than in others,

in Optical Instruments. 19

Now, opticians have not been entirely insensible to the advantages,
to be obtained by excluding all inefficient light ;—being aware that
no kind of blacking applied to the inside of an optical tube, is
sufficient to effect that salutary purpose, they have had recourse
to other means, though inadequate to the end in view.—Thus it is
common in a refracting astronomical telescope, to meet with one
stop and sometimes two, placed in the interval between the object
and eye-glass; the apertures of the magnifiers, are likewise con=
tracted on the same principle. But these stops are never in suffi=
cient number, or sufficiently contracted, or placed in such situa~
tions as they should be to be efficient, at least it has never fallen
to my lot to see any such. It seems to me, as if they were pos=
sessed of some superstitious dread of cutting off some of the light
of the object glass by inserting stops; or perhaps have wished to
shew their customers, that the apertures of their glasses were clear,
it being a common trick to make a large object glass, and then to
cut off the effect of the imperfect edges by a contrivance, such as
has been mentioned, which ordinary purchasers are not aware of,
and thus, suppose, the instrument to be much finer and better than
it really is; at least it is not uncommon to meet with this species
of fraud in the works of the continental artists, who are
yery fond of making larger object glasses than the English work~
men. To enter into my subject, I shall here as succinctly as
possible, describe the method which I have experimentally found
to answer best for stifling fog in the astronomical refractor. It is
a consideration which must obviously present itself, that if an eye=
hole be placed at the end of a telescope, precisely of the size and
precisely in the focus of the pencil of rays produced by any par
ticular magnifier, that the end here proposed will be attained, as
in the Gregorian and Cassagrain telescopes ; it will moreover,
confine the eye truly to the axis of the tube, and thus prevent
us from seeing any of that colour in the image, which may
always be perceived in the best instruments, when the eye is a
little removed from its true position. Nevertheless, I have after
sufficient trial rejected this method, as less expedient than another
which I shall point out, on account of the difficulty of executing it
C 2

20 Dr. Goring on False Light

properly with high powers, as well as that it confines the field of
view, and is disagreeable to the eye. It is evident, that with high
powers the pencils of rays will be exceedingly small, therefore if
the aperture of the eye-hole is too large it will be ineffectual, if too
small it will obstruct light : it must therefore be executed to a very
great nicety, which is not always to be expected; besides in a
case of such delicacy, if the eye-piece be not screwed on to a par-
ticular mark on the body of the tube, or if any of the parts of
which the magnifying apparatus is composed, be more or less
screwed home than at the time of adjustment, it will be highly
probable, that the eye-hole will be a little thrown out of its true
situation, and thus do away with the sole object for which it was
constructed. Thus it is, that what is perfect. in theory, will not
always answer in practice. As to using eye glasses with very
small apertures for the same purpose, (as contradistinguished from
eye-holes, placed at the ends of the cones of light, drawn toa
point by the magnifiers,) it is a method which cannot be made to
exclude false rays with any degree of precision, even though their
diameters are so much reduced as greatly to contract the field of
view. I shall now give an account of the plan I have selected as
most eligible, and which I have applied to a thirty inch and eigh-
teen inch refractor with complete success, as it seems to me. Fig. 1.
Plate II. isa drawing of the section ofarefractor, in which may beseen
seven stops in the course of the tube and eye-piece, (exclusive of
the field bar,) five of which are placed in such a manner, and of
such apertures as to pinch the cone of rays proceeding from the
object glass as tight. as possible, without intercepting any. It will
be obvious that no foreign rays, or any that are not parallel, wilt
be able to find their way to the eye, nor can any light be re-
flected from the sides of the tube, so as to become visible. To
execute this, use the following method; when the telescope is
finished in the usual way, and before any stop is inserted,
attach its lowest astronomical eye-piece to it, and find the true
solar or sidereal focus of the object glass; when thus adjusted,
measure carefully with a dynameter, the size of the pencil of rays
proceeding frora the eye-piece, and note it down. Having then

i

/

in Optical Instruments. 21

procured a plank of wood covered with paper of sufficient length,
take the aperture of the object glass, and set it off at one end of
the board, bisect it and draw a line at right angles to it, to the
exact length of its focus: fix three strong needles into the three
points of the focus and aperture of the object glass, and then
stretch a fine thread over them, which will then represent the cone
of light which forms the image; set off six or seven inches from
the focal extremity, (an efficient stop cannot be placed nearer,
without.contracting the field of view,) and ascertain the distance
between the threads at this point, which will give the diameter of
the fifth stop. Then divide the remainder of the focal length into
five equal parts, (whatever it may be,) and the distance of the
threads will give the diameter of four more stops, 4, 3, 2, and I,
in the figure, all sufficiently correct for the purpose. The stops
are then to be made and inserted into the tube in their proper
places; it will not however be amiss to make No. 1, 2, 3, and 4,
a little too large, and to confide the main business of stopping
the false rays to No. 5*, which may be attached to the eye tube,
and move along with it, in adjusting the focus of the magnifier.
This will give the instrument the power of adjusting itself, to nearer
objects on the earth, without losing any light from the effect of the
stops, which otherwise must be adjusted to the shortest focus of
the object glass, and supposed to act perfectly only with parallel
rays. It will not be amiss to haye a very small eye-hole, placed
correctly in the focus of the object glass, which will give a great
facility of adjusting the stops, as it will shew by merely looking
through the instrument, if they are correctly placed or not. Lastly,
having fixed these, apply the eye-piece, carrying the lowest mag=

* The way of regulating the aperture of this or any other stop to its situation
in the course of the tube, will naturally be by pushing it up or down, till it
strictly conforms itself to the size of the cone of rays at the point where it acts ;
when once itis settled for the lowest magnifier,so that the image of its aperture,
and that of the object glass correctly correspond, and shew no difference in
measurement by the dynameter, the business is effected for all the ether
powers, as they will always preserve the same relative proportion to each
other, whatever may be the depth of the lens which is employed to form ay
image of them,

22 Dr. Goring on False Light

nifier as before, and again with the dynameter measure the size
of the cone of rays at the eye; if it measures precisely as before,
you may be quite confident you have cut off no true light*. I dare
say it will be thought, there are already a very superabundant
quantity of stops, but, I am sorry to say, that on examining the —
pencil with a magnifier, it will most probably be found, that some
false light is still reflected from the eye tube, to cure which two
more stops will be necessary, (Nos. 6, and 7;) both of these how-
ever, must be larger than No. 5, and No. 7 the largest of the two,
or the field of view will be contracted in the low powers.—The
higher the power, the nearer an efficient stop may be placed to-
wards the focal extremity of the pencil, proceeding from the object
glass; the lower it is, the farther the stop must recede, gradually
of course, increasing in its aperture, (unless the length of the eye-
tube is increased in proportion to the focus of the magnifier em-
ployed.) I have pitched upon six or seven inches, which is a
distance for the main stop, that will suit all telescopes, and all
magnifiers which are not more than one inch focus. Here it seems
proper to observe, that when once the false light is duly excluded
from a telescope, in the manner I have here recommended, the eye
glasses may be used of any aperture, and thus the field of view
may be had of any size, even with a single eye-glass, which in my
opinion, when high magnifiers are used is a great convenience, as
it enables us to keep a celestial object in sight more easily, though
we should only see it distinctly in the axis of the telescope; more-
over, should it not be thought worth while after all, to have the
false light as perfectly excluded, as it possibly can be under all cir-
cumstances, the stops No. 1, 2, 3, and 4, may be rejected, and
5, 6, and 7 only executed; the consequence will only be, that
some false light will be rendered sensible, when the eye is not con-
fined to the centre of the eye-glass.

*T think an instrument from which all the false light is utterly excluded,
does not appear quite so luminous as it did before, for false rays are as capable
of affecting the retina, as true ones. [If we were to turn out all the disagree-
able people out of a room full of company, there would of course be fewer indi-
viduals init, but the society would, I think, be indubitably improved by the
measure. |

in Optical Instruments. 23

~T have given the full complement of stops, to render the exclu-
sion as complete as possible. As good a way as can be devised of
illustrating the effect of the stops, is the following. It is known
thata terrestrial telescope with an erecting eye-piece of four glasses,
would be rendered nearly useless by withdrawing the little stop
placed between the two glasses which erect the image, by the
quantity of fog which would be let in, (supposing the instrument
constructed in the usual way.) But in a telescope furnished with
such stops as I have described, it is of no consequence whether the
little stop is introduced or not, the performance is precisely the
same in point of distinctness in both cases. In performing this ex-
periment, it is necessary however, that the aperture of the little
stop should be correctly and truly accommodated to the size of the
pencil, which is formed by the glass, in the focus of which it is
placed, so that it shall barely admit the image of the object glass,
without cutting any of the side rays off, otherwise the experiment
will not be fair.—Opticians are apt sometimes to make these aper-
tures so small, as to intercept some of the light of the object glass
as effectually as a cap over the end of it would; for the achromati-
city of an erecting eye~piece depends very much upon the size of
the little aperture in question, Thus where the diameter of an
object glass bears a very large proportion to its focal length, it
will be impossible to admit the whole of the light proceeding from
it into the eye-tube, without at the same time destroying the achro-
matic property of the latter, by the necessity which would arise
of opening this stop too wide to consist with it. In the experiment
I have detailed, there is sufficient proof that the effect of my stops
is equivalent, indeed more than equivalent, to that produced by
the stop which is inserted in erecting eye-pieces for the purpose
of procuring distinct vision. What then? is there any merit in
having effected, by means of half a dozen stops, what may be done
well enough by one? certainly not. But take away the erecting
eye-tube, screw on an astronomical eye-piece, (either with or with-
out a field bar,) and where I ask now, is that part of structure
which is to do the work which was performed in the erecting com-
pound magnifier, now removed, by the little stop of which I have
said so much ; (supposing the telescope constructed in the usual

24 Dr. Goring on False Light

manner, thatis to say, without stops in the course of the focal dis-
tance of the object glass, or at least without effectual ones?) It
cannot be asserted, that there is anything equivalent in the instru-
ment in its present condition, to the former provision in it, for the
valuable purpose of excluding false rays, though the expediency
and utility of it in both cases, must be equally admitted or denied,
and it is clear this can only be supplied in the astronomical teles-
cope, by some such expedients as I haye resorted to.

As I conceive no one can be hardy enough to assert~that there
is no use in excluding false rays from a telescope intended to be
used at night, for viewing the heavens, it will be superfluous for
me, to set about proving that we shall see a celestial object the
better, if no light, either direct or reflected, reaches the eye, save
that actually proceeding from it. If the light of the heavens in a
star-light night, and that of the bodies which produce it are very
faint, still there is the same ratio between their brightness, and the
false light they produce, (though not so conspicuous perhaps) as
there is in that of terrestrial objects. Indeed it is perfectly well
known to astronomers, that in the darkest night, wearing a black
hood over the eyes, greatly facilitates the vision of very faint and
delicate objects, such as nebule, &c., from the sensibility and tran=
quillity induced by these means in the retina, rendering it sus-
ceptible of the slightest impressions. Surely the effect of foreign
light reaching the eye directly, or through the medium of a
telescope, must be equally pernicious. It is in viewing the class
of objects here designated, that the utility of the stops I have
described will be found; no one will expect that they can render a
telescope better able to define or divide a star, because these pro-=
perties depend upon the perfection of an entirely different part of
its structure. I shall take my leave of the subject, by asserting
that if any one should choose to maintain a contrary opinion from
myself on the affair of excluding false rays, he must, to preserve
consistency, assert that there is no use in the eye-hole of the Gre-
gorian and Cassagrain telescope, (if used at night,) and should
therefore in using these instruments, content himself with such a
one as is applied to common spy glasses, just to keep his eye in the
axis of his instrument, '

in Optical Instruments. 25

I now proceed to the next part of my subject, which is the con-
sideration of the Newtonian telescope. This admirable instrument,
such as could only be expected from the genius of the immortal
philosopher who invented it, has, (as a necessary consequence of
its construction,) among its other valuable peculiarities, that of
having less false light in it than any other kind of telescope.—The
same striking effect, therefore, will not be manifest in excluding
the trifling fog there is in it, as in another construction where it is
more abundant. Nevertheless there is something to be done.—If
we examine the pencil of rays proceeding from its eye-piece with
the magnifier, it does not precisely represent the image of aspangle
or a piece of black cloth, as it should do ;—a good deal of foreign
light may be seen, formed partly by the side of the tube behind the
diagonal metal, and partly by such portion of the end next the
large mirror, as the plain one can reflect along with the image, toge-
ther perhaps with some reverberated by the little tube which carries
the magnifiers.

In Fig. II. is represented the method I haye taken to remedy
these imperfections in a 77-inch focus, and seven-inch aperture
Newtonian*. The alterations from the common construction, are

* On exhibiting these alterations to those celebrated artists, Messrs. Tulley of
Islington, I learnt from them that they had lately made an arrangement of the
same description, in a Newtonian telescope, made for Mr. Camfield of North-
ampton. These gentlemen (whose unrivalled pre-eminence in their profession,
needs not my feeble testimony, or eulogium) fully admit that the exclusion of the
false light, makes a great difference in the performance of the telescope, in the
day-time, but do not seem to think any alteration is to be perceived in viewing
celestial objects. Iam aware, that I am paying myself an indifferent compli-
ment in differing from such authorities. Ihave given my reasons for so doing,
and cannot help still being of opinion, that it is scarcely possible to select any
object in the heavens, and to view it without rays from a variety of others also
finding their way into the telescope, and thus disturbing the singleness of vi-
sion, which would exist was there but one star or object in the heavens to emit
light. I think, in particular, that the double ring of Saturn, and its belts and
shadows are not perfectly seen, unless the telescope employed to view them,
will show black objects perfectly black, and white objects perfectly white, and of
course all the intermediate gradations of shade correctly ; very few telescopes
will shew the division between the rings of Saturn quite black, (as mine does,)
owing to the false light so generally prevalent in them,

26 Dr. Goring on False Light

as follows: the tube which carries the magnifiers is seven inches
long, instead of being only two inches or perhaps less, as is usual
—the diagonal metal is likewise placed nearer than usual to the
large one, so that the length of the telescope is reduced about five
inches; this is of course necessary to render the pencil of rays re=
flected at right angles from the axis, long enough to act with the
increased length of the eye-tube. (As the diameter of the spec-
trum of the great mirror increases as we recede from its focal ex-
tremity, more of the small plain one will in this case be called upon
to act ; it however will still do the work without any increase in its
size; mine is 1-3, inch of circular diameter, yet its entire surface is
not employed.) By this arrangement a sufficient length of eye-
tube is obtained to insert the stops 5, 6, and 7, as in the refractor,
No. 5, is the efficient stop as before and is ;7; inch in diameter,
The extrusion of the aberrant light is complete as long as the eye is
in the axis of the instrument.

It would of course be impossible to insert any stops similar to
those, 1, 2, 3, and 4, in the refractor to render the effect more
complete; nevertheless, I think, were it any object, a Newtonian
would by the aid of the contrivance I have applied to mine, act
sufficiently well with a skeleton tube only. It now remains for me
to describe the new adjustment which the adoption of so long an
eye-tube has compelled me to have recourse to, for it is evident
that any want of centricity and parallelism in the lenses composing
the eye-glass to the axis, which might be tolerated in a very short
tube, will be perfectly insupportable when aggravated by a longer
one: moreover, the stop No. 5, (which I suppose to be so ad-
justed as barely to suffer all the light of the great metal to clear it)
will, if not truly concentrical with the cone of light on which it
operates, evidently impede some, as in such a case is perceptible
by looking through the small eye-hole recommended in adjusting
the refractor, or by examining the extreme pencil after it has passed
the eye-glass with a magnifier. It is evident, I think, that the
adjustment of a Newtonian is complete, when the pencil of rays
which is reflected from the small metal, truly perforates the axis
of the eye-tube, and the centres of the lenses composing it; it mat~

in Optical Instruments. 27

ters not, I conceive, at what angle or in what direction the said
cone of rays proceeding from the large metal be thrown by the diago-
nal one, provided these conditions are fulfilled, (supposing of course
the position of the small metal to be the centre of the tube, so that
it shall truly receive the whole of the light of the great one.)
We may, therefore, either adjust the small metal to the eye-tube or
the eye-tube to the small metal, or we may do both, which latter
will probably be the most expedient, and is the method I have pre-
ferred; I have effected it in a very simple manner, by having the
tube made to fit loosely into another wider piece, which is screwed
on in the usual way, to the side of the telescope:—the vacancy be-
tween them is filled up with wax, the inner tube is tight at the
bottom of the external one, by the interposition of a small setting
chamferred at the edge, but admits of a slight rotatory motion to-
wards the eye-glass by heating the wax with the flame of a candle
- which is inserted into the external tube, and which unites them
both together; time will be given to adjust it before the wax cools,
when it will all set tight, and will not be liable to get out of order.
Two small niches should be made, one in the shoulder of the screw
of the external tube, and the other in that of the female screw to
which it is applied, to be a guide that the two pieces may always
be serewed home to a particular point: or it is very probable the
adjustment may be spoiled, because it will be a chance if the eye-
tube when fixed, is precisely at right angles to the side of the tele
scope. A variety of methods of effecting this adjustment will pre-
sent themselves to the workman, instead of that which I have used,
which though it answers very well, yet does not look very elegant
or scientific. Thus, instead of the wax, three screws might be
used, fixed into the external tube; or such a contrivance as is repre-
sented in Fig. II., by having counter screws to play against those
by which the setting for the eye-piece is attached to the rackwork,
on the side of the telescope, &c. Now it is not my intention to
assert that this adjustment is absolutely indispensable, for I haye
not a doubt but that a superior workman might execute a long eye-
tube, such as I have employed, so that nothing but the usual adjust-
ments would be required; still I think that no Newtonian would be

28 Mr. Swainson on the Characters

injured by having such an apparatus to it as I have recommended,
even though the eye-tube were only of the common length; it is
certain it could do no harm at Jeast. I think I can, moreover, with
confidence assert that increasing the distance between the small
metal and the eye-glass, for the purpose of applying stops, will not
be found to make the least sensible difference in the performance
of an instrument, as far as the figure of the small metal is con-
cerned, provided it is of the standard goodness*; if but imperfect
such an alteration will evidently try it more, and this will be shewn
by examining a double star which will probably vary slightly
in the distance at which the stars appear separated, (ceteris pari-
bus,) according as the eye-glass approximates to, or recedes from,
an imperfect diagonal. To conclude, as an Herschelian telescope
is nothing but a Newtonian, used without the interposition of a
small metal reflector, whatever has been said of the latter, will
equally apply to it, and the same principle in the eye-tube and ad-
jJustment, will for the same reasons be equally adapted to both,
though the manner of execution will be different; I have, however,
made no experiments on this kind of telescope.

[The portion of this paper relating to Microscopes is reserved
for our next Number. ]

eee ener teil
Arr. IV. The Characters of several New Shells, belonging
to the Linnean Volute, with a few Observations on the pre-

sent State of Conchology. By William Swainson, Esq.,
F.R. and L.S.

Tue study of conchology has now become so general, or, if I may
be allowed the term, so fashionable, that the number of elemen-
tary works is truly surprising. The new systems of the French
conchologists have been translated, explained, and advocated, in
various publications; while the admirers of the Linnzan method,

* It is evident that if the diagonal metal were quite perfect, it could make no
difference at what distance the eye-glass was placed from it; if decidedly im-
perfect, it is no less plain that the nearer the eye-glass is placed to it the bet-

ter, because the less of the edges will be called into action, which will of
course be the worst part.

of several New Shells. 29

have not been backward in expressing their warm attachment to
the plan of the great Swedish naturalist. It is not my present inten-
tion to speculate upon the respective merits of these systems. In the
study of no class of the animal kingdom have there been so few ab-
solute facts discovered, whereon to build a truly natural system, as
in that of the testaceous mollusca, In the history of those families
which: are known, anomalies have been discovered, which bafile
explanation, and obstacles almost insurmountable, from the very
nature and hab:tat of the animals, conspire to retard that rigid in-
vestigation of their economy, which must alone form the basis of
their perfect arrangement.

But while so many writers have been engaged in forming systems
and constructing genera, the elucidation of species has compara-
tively been neglected.

An extensive acquaintance with species is the first step to a
knowledge of natural divisions. In every branch of natural history
those who have seen and studied the fewest individuals, will be
most apt to create new genera; ‘‘ when they have seen more, they
will discover the intermediate links which unite different genera;
and thus be forced to join what they formerlyseparated*”. Iam
fearful this has not sufficiently been considered by the authors and
advocates of the French systems: it may be doubtful if their generic
distinctions are not too much refined ; butit is certain that a know-
ledge of the science is daily becoming more unattainable to all but
professed naturalists.

While this revolution of classification and of genera is going on,
our cabinets are crowded by innumerable species, some of which
we know not how to name, while others (well known by the figures
of the older writers) remain undescribed: new species are con-
tinually pouring in upon us to augment the number: and although
the student may be perfect in the elements of his system, he knows
not how to proceed, or where to turn, if he ventures on the inyesti-
gation of species,

The volumes of Lamarck (His. Nat. des Animaux sans Ver-
tebres) have indeed done much to remedy this evil. They contain -

* Wildenow, Principles of Botany, P, 175, “Sect, 163,

30 Mr. Swainson on the Characters

a considerable increase of new species, and a more perfect eluci-
dation of many of the old ones; but, on the other hand, the same
over-refinement which marks the characters of his genera, will be
traced in the discrimination of his species; this is more particu
larly the case in his account of the genera Conus, Oliva, and Helix.
Let me not, however, be misunderstood, as wishing to depreciate
the merits of this great man. His general reputation could not be
affected either by my praise or my censure. But obliged, as he
has been, to employ the sight of another in finishing his latter
volumes, it would perhaps have been better for his own sake, and
that of the science, to which he has devoted his long life and great
abilities, ifthey had never been published.

- The importance of monographs, or complete histories of parti-
cular tribes, or families, in every branch of natural history is un-
questionably very great; for their object is, not only to ascertain
the limits'of genera, and the affinities and analogies, which the indi-
viduals of such genera bear to others, but likewise to include the
history of all the species thereunto belonging. To accomplish this,
however, is in the power of a very few. Access must be had to the
rich contents of foreign museums, and of costly libraries, to supply
what may be deficient in minor collections; and it is from this
cause that nearly all the monographs of extensive families have
proceeded from naturalists in the charge of public museums, or in
the possession of immense private collections. From the labours
of these men science has received the. greatest assistance. But,
although few can enjoy the advantages such materials afford, con-
siderable benefits will be derived from the labours of those, who
frame a correct diagnosis of individual species ; particularly when
relative characters are subjoined, and comparisons made between
others to which they bear a resemblance. When it is considered
how many rare and unknown shells have lain for years in the cabi-
nets of mere collectors, and how much greater is the number of
those species more usually seen, but which are likewise unrecorded,
the value of these isolated descriptions will be rightly understood.
They are the indispensable materials for completing a general
suryey of the natural world, and constitute the ultimate object of

of several New Shelis. 31

all systems; namely, such a knowledge of the individuals, as will
enable the student to assign to each ‘‘a local habitation and a
name,”

I shall now proceed to describe several beautiful shells; dena
of uncommon rarity, and apparently unknown to modern writers :
the four first belong to the genus Voluta, as it is now restricted ;
and the remainder to Mitra, a genus towhich I have long paid much
attention, with the ultimate hope of illustrating it by a distinct
monograph.

Votura. Lam. (Diy. 1. Musicales.)

Voluta chrysostoma.

V. testa ovata, albente, lineis angulatis maculisque castaneis or=
nat4; anfractibus spinis brevibus, concavis coronatis ; apice crasso,
obtuso, levi; apertura aurea,

_ Shell ovate, whitish, with angulated chestnut lines and spots ;
whorls crowned by short concave spines; apex thick, obtuse,
smooth ; aperture golden.

Voluta chrysostoma. Sec. Exotic Conch. Fas. 5. ined.

Voluta luteostoma? testa obovata, angulata, lineis et venis fus-
centibus i in fundo albido undulata sub-perforata, anfractibus cinctis
nodis conicis, apice obtuso, basi valde emarginata, columella pli-
cata plicis quatuor solidis, fauce lutea. Chemnitz xi. p. 18, tab.177.
F. 1707-8.

DESCRIPTION.

_ The shell in its habit, approaches V, vespertilio: its total length
is about two inches, of which the spire occupies not more than half
an inch: its form is oval, and its surface without sculpture: the
basal volution, and the two first whorls of the Spire, are crowned
by a row of short thin vaulted spines, rather acute, and resembling
those on V. diadema, (Ex. Conch, Fas. 1.) The remaining three
spiral whorls are perfectly smooth, the middle one being by much
the largest, and the whole forming a thick and somewhat obtuse
cone. The base is deeply emarginate, and the plaits on the colu-
mella, (which are four in number) are very thick, The ground
colour of the specimens before me is nearly white, with broad

32 Mr. Swainson on the Characters

longitudinal shades of deep chestnut, broken into rows of angulated
whitish spots of various sizes, and disposed in a longitudinal di-
rection. The spire is white, with a few brown undulated lines on
the lower whorls; the inner lip yellowish white, and the throat or
inner aperture golden yellow.

This shell, as far as regards English collections is unique. It
is now in the possession of Mr. Mawe, I believe, and in all proba-
bility may be found to inhabit the Indian Ocean.

The Vol. luteostoma of Chemnitz,(a shell passed over by Lamarck,
and all systematic writers,) bears a strong resemblance to this spe-
cies, but I have many doubts if it be really the same. In this
genus, the form and sculpture of the terminal whorls of the spire,
afford the most certain specific distinctions; now in the V. luteos-
toma, these terminal whorls are represented as graduating to an
obtuse point, whereas in the shell above described, they are very
thick and papillary. V. duteostoma is stated to be “* subperforata,”
but this V. chrysostoma bears not the slightest indications of such
a character, neither is the description, ‘‘ anfractibus cinctis nodis
conicis,” applicable, if intended for the latter species. On the other
hand, the two shells agree in their general form, habit, the golden
colour of their apertures, and nearly the pattern of their markings.
I have preferred however, for the present, to keep them distinct ;
because every conchologist must be sensible, more perplexity has
been introduced into the science, by creating too few species than
too many.

Votuta GRACILUS.

V. testa oblongo-fusiformi, lineis undulatis picta ; spira producta
plicata; labio exteriore subreflexi; columella 4 plicata.
Shell oblong-fusiform, with undulated lines; spire lengthened,
plaited ; outer lip sub-reflected; pillar 4 plaited.

DerscriPrion.

This is a most elegant shell, belonging to the same group as that
filled by V. undulata and its allies; from all of which it may at
once be known by the great prolongation of its spire, which is
nearly the length of its aperture. The whole shell does not exceed

of several New Shells. . 33

two inches and a half in extreme. length; the basal volution is
smooth; but the three next whorls of the spire are plaited, and
slightly nodulous; these plaits then disappear, and leave the ter-
minal volutions quite smooth; the apex is obtuse, but not enlarged ;
the base of the shell is contracted, and the emarginate notch rather
slight; the margin of the outer lip is somewhat reflected, and on
the columella are four slender and nearly equal plaits. The colour
is pale brown, elegantly marked by longitudinal, slender, waved,
and angulated lines of a deep fulvous brown; at the top, bottom,
and middle of the basal whorl, these lines are more thickened and
deeper coloured, so as to form three transverse bands. Another
specimen of this species was covered over with a reddish tinge,
which nearly obscured its markings. The brown lines are also
continued on the spire, but are fewer and more remote.

Ob. Two specimens of this elegant voluta were brought home
by one of the South Sea trading vessels from the Bay of Island,
they are now in the possession of Mr. Mawe.

VoLuta CostaTa.

V. testa ovato-oblonga, costis sub-mucronatis, pallida, lineis
fulvis interruptis fasciata; basi granos4; spira mediocris apice
levi, obtuso; columella multiplicata, plicis tribus inferioribus max-
imis.

Shell ovate-oblong, with sub-mucronate ribs, pale, and banded
with interrupted lines of fulvous; base granulated, spire moderate,
the tip smooth and obtuse; pillar many plaited, the three inferior
plaits largest.

The situation of this species, appears intermediate between the
Vol. festiva and mitreeformis of Lamarck, but its form cannot be
compared to any other. It is little more than two inches and a
quarter in extreme length ; the spire is rather produced, and occu-
pies oneinch, With the exception of the terminal whorl at the apex
of the spire, (which is perfectly smooth and obtuse,) the whole shell
is marked by numerous, regular, convex ribs, about the same thick-
ness as the breadth of the space which occurs between them; these
ribs form a row of short obtuse spines, which crown the summit of

Vou, XVII. D

34 Mr. Swainson on the Characters

each yolution; leaving between them and the suture an open chan-
nel; at the base of the shell are deep striee, which cross the ribs,
and produce a rough granulated surface. The ground of the
shell is pale flesh colour, crossed on the ribs by bands of short
slender fulyous lines; interspersed by a few orange spots: the
aperture is also flesh-coloured, and the margin of the outer lip
sharp and rather inflected. The upper part of the columella is
crossed by numerous slender plaits, and at the lower part are three
others much larger.

Described from a specimen in the possession of Mr. Mawe.

0b. 1. The V. festiva of Lamarck, except from his description, is
a species unknown to me. According to the writer, it differs from
V. costata in being fusiform and ventricose, resembling in shape
V. magellanica; it likewise appears destitute of the numerous
small plaits on the columella, and of the obtuse coronations,
formed by the summit of the ribs. These two shells with V, nucleus
Lam. (which is Voluta harpa of Mawe’s Introd.) V. mitreformis,
and another undescribed species in my possession, constitute a
new group in the genus; characterized by having the principal
plaits on the pillar, situated at the base of the aperture.

Ob. 2. It may be necessary to observe, that although two shells
already appear in the Linneean classification under the name of
voluta costata, neither of them in fact, belong to this genus.as it
now stands, One of these (the voluta nassa of Gmelin,) is a young
shell of a species of Nassa Lam.; the other, (Vol. costata of Gmelin
and Dillwyn,) is the Mitra Subulata of Lamarck.

Mirra. Lam. Cuyv.
Mirra tessellata,

M. testa ovata, leevi, striis transversis remotis et punctis, al-
bente, lineis fulvis transversis et longitudinalibus cancellata, labii
interioris basi fusca; labio exteriore leevi.

Shell ovate, smooth, with remote transverse punctured strie;
whitish, cancellated by transverse and longitudinal fulyous lines;
inner lip brown at the base, outer lip smooth.

DrscriPrion.
Habit of Mitra pertusa, but is much smaller in size, and less

_ of several New Shells. | 35

ventricose; the spire also is shorter in proportion, but more thick-
ened and obtuse; total length one inch three quarters; the whole
shell is crossed by delicate remote striz, which are minutely
punctured; the aperture is rather longer than the spire, and toge-
ther with the inner lip is pure white, the base of the latter is how-
ever stained by dark chestnut brown; the outer lip is rather inflected
and is perfectly smooth; this latter character will at once distin-
guish this species from all its allies; the pillar has four plaits.
The colour is uniform yellowish white, with slender fulvous,
transverse lines following the indented strice; these fulvous lines
are crossed by others more broken and produce a singular resem-
blance to the mortar divisions of brick work ; adjoining the suture
is a row of small fulyous spots.

This shell I only know from a beautiful specimen in the posses-
sion of Mr. Mawe.

Mirra GUTTATA.

M, testa ovata, sub-fusiformi, levi, striis transversis punctis,
fulvA maculis albis varia; labio exteriore crenato; columella 5-
plicata. .

Shell ovate, sub-fusiform, smooth with transverse punctured
‘striee, fulvous variegated with irregular white spots; outer lip cre-
_ nated, pillar 5-plaited.
shops DEscRIPTION.

Habit of the last; but is a much smaller shell, having the base
more contracted, and the tip more acute; the striz also are deeper
and the punctures larger; it seldom exceeds an inch in length; the
whole shell is brownish yellow, irregularly marked by white spots
and blotches, these last spread over the spire, and form an irregular
band across the middle of the body whorl; the aperture.is white,
the outer lip crenated, and the pillar has five plaits.

Ob. Two specimens of this species are in my own collection ;
but I am unacquainted with its locality,

Mirra Fusca,
M. test crass4, ovata, leyi, fusci; spiree contracie sutura sub-
tilissimé crenata; labio exteriore crasso, gibbo, lwyi; columella
4-plicata,
D2

36 Mr. Swainson on the Characters

Shell thick, ovate, smooth, brown; spire contracted, suture mi-
nutely crenated; outer lip thick, gibbous, smooth ; pillar 4-plaited.
DuEscRiPTION.

Length one inch, habit of M. crassata Sw. the basal volution is
thick and rather ventricose; the spire is short and abruptly slen-
der, having the upper margin of the whorls projecting beyond
the suture, and minutely but regularly crenated ; the whorls are
likewise crossed by a few remote strize, the inner margin of the lip
is thickened, and gibbous, except at the aperture, which is white.

The whole shell is of a uniform fulyous brown; inhabits the In-
dian ocean, and is very rare.

Mirra Acuminata.

M. test crassa, levi, albente ; spird contracta, attenuat&é acumi-
nata, apertura longiore; labii exterioris crassi margine inflexo,
levis; columella 4-plicata. Shell thick, smooth, whitish; spire
contracted, attenuated, acute, longer than the aperture; outer lip
thick, the margin inflexed and smooth; pillar 4-plaited.

On a cursory glance this shell (if in an imperfect state) might
easily be mistaken for the last; when perfect, it is about an inch
and a half long (the spire occupying considerably more than
half this length) and is faintly striated. The spire when unin-
jured is long, abruptly contracted, and terminates in an acute
point. This part is so delicate, that in two specimens out of
three which have come under my notice, it was wanting. The
whorls are crossed by delicate indented strie, but are not in
the least convex ; this character gives the suture an appearance of
being channelled ; the outer lip is somewhat inflexed, the margin
smooth, thick and slightly gibbous within the rim; the base is ob-
tuse, and the whole shell white, covered with either a yellow or
reddish brown epidermis.

Inhabits the Mauritius.—A small though beautifully perfect spe-
cimen is in the possession of Mr. Mawe.

Mitra Canrinata.

M. testa gracili, fusiformi, fusca, anfractibus medio carinatis,
juxta suturam striatis, columella, 4-plicata.

' Shell slender, fusiform, brown, whorls carinated in the middle,
and striated transversely near the suture ; pillar 4-plaited.

of several New Shells. 37

Drscrirtion.

A remarkably slender fusiform shell, about an inch long ; the
spire being of equal length with the aperture ; the shoulder of the
basal volution, and the middle of the spiral whorls are crossed by
a carinated ridge ; between which and the suture, are two or three
elevated transverse strize; the rest of the shell is quite smooth; the
aperture is white, and smooth within; the inner lip marginated,
and the pillar 4-plaited. It is covered by a uniform brown epi-
dermis, beneath which the colour is yellowish; base deeply emar-
ginate, and slightly recurved.

Inhabits Sierra Leone, from whence it was received by Mr. Mawe.

It is a species at once distinguished by its crenated whorls,
and should be placed in the same division as M. vulpecula and
melongena.

Mitra STRIGATA.

M. testa levi, castaned, strigis longitudinalibus obsoletis, al-
bentibus ornata; apertura spira breviore, alba; columella 4-plicata.

Shell smooth, chestnut, with obsolete longitudinal whitish
stripes; aperture white, shorter than the spire ; pillar 4-plaited.

Habit of M. carbonaria, Sw. and M. melaniana, Lam: the specimen
before us measures two inches in length, the spire occupies an inch
and one-tenth and is rather thick. The top of each whorl where it
joins the suture, is turned and prominent, every part of the shell is
destitute of sculpture and very smooth; the base is contracted and
the pillar has four teeth, with the indication ofa fifth. The colour is
arich glossy chestnut, striped at unequal distances, with paler,
narrow, longitudinal stripes, which form dots of pure white adjoin-
ing the suture; the aperture and inner lip are also white.

The only specimen of this beautiful mitre with which I am ac~
quainted, is in the possession of Mr. Mawe.

Mirra Bicotor.

M. testa leevi, fusiformi, alba, facia fusca lata cinctd, spira anfrac-
tusque vasalis parte superiore striis cancellaiis punctis insculptis ;
striis basalibus simplicibus.

Shell smooth fusiform, white with a brown band; spire an .,

38 Mr. Swainson on New Shells.

upper part of the body whorl with cancellated punctured strie;
base with simple striz.
DeseRIPTION.

Shell about three quarters of an inch long, in shape, habit, ‘i
even in colour, resembling M. casta (Zool. Ill. pl. 48.) but the
brown band, (which in that shell is merely formed by an external
epidermis,) in this is internal, and delicately waved with capil-
lary longitudinal lines of whitish; the longitudinal striz are
clouded and simple, but the transverse striee are more remote,
and deeply punctured; those in the middle of the body whorl, and
of the base are likewise simple; the plaits on the columella are
four, and very prominent; the base of the pillar is tipt with brown.

Ob. This shell, together with M. casta, olivaria, dactylus and
oliveformis, constitute a particular group, distinguished by the
plaits of the pillar extending far beyond the aperture.

Inhabits the South Seas? mus, nost.

Art. V.—Account of the Earthquake tn Chilt, in Novem-
ber, 1822, from Observations made by several Englishmen
residing in that Country.

{Communicated by F. Piace, Esq.]

Cur is a long narrow country, lying between the mountains of
the Andes on the east, and the Pacific Ocean on the west. It ex-
tends from 20° 20’ to 43° 50’ south latitude, and from 68° 50’ to
74° 20' west longitude from Greenwich, its length being about~
1350 miles, and its average breadth about 130 miles.

While under the dominion of Spain, Chili was visited by very
few Europeans. Its great fertility, its abundance of metals and
minerals, its agreeable and healthy climate, have, since it has been
declared independent, induced a considerable number of English-
men, and a few other foreigners, to become residents, and the
number is continually increasing. j

The country rises gradually but irregularly from the-sea coast to
the mountains; it is exceedingly diversified, but the principal

Account of the Earthquake in Chilt. 39

feature is its formation into valleys, surrounded by hills, many of
them rising to a considerable elevation. .

The whole country may be divided into two regions or climates,
the one humid, the other dry, separated from each other by the
river Maule, which in 35° 10’, falls into the Pacific Ocean.

South of the river Maule the climate is variable; rain falls at
intervals during the whole year, and timber trees are in abundance.
North of the river Maule the rains are periodical, and fall only
during a particular time of the year. At Valparaiso, the principal
sea-port of Chili, and for about forty miles to the northward, the
rainy season commences in May and terminates in September.
Further to the northward, the rainy season is of shorter duration,
diminishing gradually, until at the northern extremity of the coun-
try, it totally ceases. To the southward of the Maule the time in
which rain falls gradually increases, and, at the southern extre-
mity of the country, there are but few intervals of dry weather.

Chili is never free from earthquakes ; scarcely a week ever passes
without one or more being felt, in some part of the country, but as
the shocks seldom do any damage, the inhabitants pay but little
regard to them.

It is now nearly a hundred years since the former great earth-
quake, and a persuasion seems to have prevailed among the peo-
ple that no very considerable earthquake would happen oftener
than once in twohundred years. Partial earthquakes, doing much
damage, have always happened at intervals of a few years. The
town of Coquimbo was nearly destroyed by an earthquake in 1820.
The shock, was local, and produced no alarm in other parts of the
country.

On the fourth of November, 1822, the town of Copiapo, in S.
lat. 27° 10’, was visited by a severe shock, which damaged many
houses; this was followed, the next day, by a much more violent
earthquake, which nearly destroyed the town, and did considerable
injury to the town of Coquimbo, in 8. lat. 29° 50’.

The great earthquake on the night of the 19th of November, 1822,
was felt over the whole surface of the country, from the mountains
to the sea, and from one extremity to the other. Its force seems to

40 Account of the Earthquake in Chili.

have diminished in a pretty exact proportion to its distance from
Valparaiso. is

Its effects are thus described by an Englishman, tededinds at
Concon, near the mouth of the river named in the maps ‘“ Rio
Quillota.” Concon is about fifteen miles N.N.E. of Valparaiso, as _
the crow flies.

“ At half-past ten, on the night of the 19th iauiedheal I felt
the first oscillation. I was writing at the time; starting from my
chair, I paused for an instant, expecting the shock would subside,
as others had done; but the falling of glasses from the sideboard,
the cracking of the timbers, and the rattling of the tiles from the
roof, fully apprized the whole family of their danger, and all ran
out of the house. The house was violently agitated, and was
falling to pieces, but freed from the apprehension of being buried
in the ruins, my attention was forcibly drawn to the phenomena,
which I endeavoured to observe as accurately as possible. Scarcely,
however, was this resolution taken, and before the first shock had
entirely subsided, a second and much more violent one succeeded;
this was accompanied by noise, which appeared to be deep seated
in the earth, perpendicularly to the spot on which we stood. The
duration of this shock was about two minutes; it was succeeded
by a third, also accompanied by noise, less loud than that which
accompanied the preceding shock. The shock was less violent
than either of the two former shocks, and of less duration. These
shocks occupied about five minutes of time. Shocks, at intervals,
of four and five minutes, continued for nearly an hour, after which,
they became less frequent during the remainder of the night, and
of very different intensities, some being rather severe, and others
hardly perceptible. The three principal shocks may be said to con-
stitute the earthquake.

“« At the commencement of the earthquake, the atmosphere was,
as is usual at this time of the year in this country, quite free from
clouds, the moon and stars shone with splendour; there was no
atmospheric indication of change of any sort, either before or after
the earthquake. Some persons say they saw an unusual light in
the horizon to the southward, but I, who was expecting some

Account of the Earthquake in Chili. 4]

_ change, and was prepared to observe any that might have occur-
red, saw none whatever. |
“ During the earthquake the ground rose and fell with great vio-
lence, and with almost inconceiveable rapidity. There was cer-
tainly no undulatory motion, though many unobserving and unre-
flecting persons suppose this to have been the case. I had astrong
suspicion at the time, since confirmed by observation of its effects,
that there was a powerful horizontal motion, but as I could not
perceive it as coming from any particular point, I concluded at the
time that I was mistaken. The circumstances which make me now
conclude there was a horizontal motion, are observations I have
since made in many places, in which walls, and even houses, have
been partially twisted round, and from the fissures round the roots
of the largest trees. At Quintero, ten miles to the northward of
Concon, are several large palm-trees ; three of these standing so as
to form an equilateral triangle, lashed one another like willow rods,
and beat or shook off many of their branches. The motion of these
trees seems to have been horizontal and circular, since each of them
cleared a space in the ground round its stem, several inches wide,
and this was the case also with other large trees in different places,
“ The sensation we experienced during the earthquake, was pro-
bably the same we should have felt had we been conscious that a
mine had been sprung beneath us, and was about to blow us all
into the air. .
“On examination next morning, at daylight, I found the earth
full of fissures, some of them very small, while others were from
two to three feet wide. In many places sand had been forced up,
and had formed small hillocks. In the most recently formed allu-
vial soil near the river, water and sand had been forced up together,
there being many large truncated cones of clean washed sand, each
of which had a hollow in the centre, like the crater of a volcano.
The same phenomenon was observed in several places; in other
places, large quantities of soft mud had been forced up, and spread
itself over the surface of the land.
“ The surface of the country has been raised all along the coast,
as far as my information extends. It seems to have been raised

42 Account of the Earthquake in Chili.

highest at the distance of from two to three miles from the shore,
diminishing both ways. The rise on the coast is from two to four
feet; at the distance of a mile inland, the rise must have been from
five to six or seven feet; for in the cut for the tail water course of
amill, at the distance of about a mile from the sea, a fall of four-
teen inches has been gained in little more than a hundred yards.

“ At Valparaiso, near the mouth of the Concon, and along the:
coast northward to Quintero, rocks have appeared in many places,
where none before were visible. The high-water mark along shore
is about three feet above the place the tide now reaches, and. a
vessel, which had been wrecked on this coast, and which could only,
be approached at low water in a boat, is now accessible on dry land
at half tide *.

“¢ At Valparaiso, not a single house escaped being damaged; it
is somewhat remarkable, however, that although the ground was
raised bodily, and considerably, those houses whose foundations
were on the rocks, were less damaged than those built on the allu-
vial soil. All the houses at Valparaiso are built of adobes (sun-
dried bricks), cemented with clay. These were thrown into heaps
of rubbish, or torn and rent in all directions. The town had the
appearance of having suffered a heavy and long continued bom-
bardment. Upwards of three hundred persons were buried in the
ruins. Had the earthquake happened two hours later, very few of
the inhabitants would have escaped.

‘* After the earthquake, the inhabitants encamped upon the hills
above the scene of desolation, in the best way they could; this was
thought less of a hardship than it would have been thought in most
other countries, from the fine warm weather, the certainty as was
concluded of dry weather, and the small quantity of dew which, at
this season of the year, falls in Chili. To these hills goods of all
sorts, furniture, and every thing else, were brought, and laid in the
open air. The damage done to this thriving town will not be re-
paired in many years.

«« The church of La Merced presented a striking instance of the

* There is very little variation of tides on this coast, the sea never rises anprG
than four feet at the full of the moon, .

Account of the Earthquake in Child. 43

violence of the earthquake; the tower, sixty feet high, which served
as a belfry, was levelled to the earth. Its solid walls of burnt
bricks; well laid in mortar, were shivered in pieces; the two side
walls, full of rents, were still standing, supporting part of the shat-
tered roof, but the two end walls were entirely demolished. On
éach side of the church were four massive abutments, six feet
square, of good brick work; those on the western side were thrown
down, and broken to pieces, as were two on the eastern side; the
other two were twisted off from the wall, in a north-easterly direc-
tion, and left standing.

ey te :

bad 24

: . _ N i as
BOG, Dy gy |} Church

of |

LaMorecd

~ “On board the admiral’s ship in the harbour, where more secure
than ashore, the effects of the earthquake, so far as the situation
permitted, observations were made with great accuracy. Tere three
distinet shocks were felt, the second was observed to be by far the
strongest, and its duration, as had been noticed at Concon, is stated
at two minutes. The effect upon the ship was the same as would
have been produced had she suddenly sunk down upon a rock. It
appeared as if her bottom had been struck with prodigious force ;

44 Account of the Earthquake in Chilt.

the vessel vibrated in an extraordinary manner, her timbers cracked,
and she appeared strained throughout.

“‘ At Santiago, the capital, at ninety miles distance from the sea,
and about twenty miles from the mountains of the Andes, the
earthquake was less severe; no houses were thrown down, al-
though many, as well as the churches, were much damaged, but
no lives were lost. Here, however, as in other places, the inha~.
bitants removed from the town, and camped out in the open air.
The effect of the earthquake atAconcagua, about fifty miles N.N.W.
of Santiago, was much the same as at Santiago, Millipilla, sixty
miles S.E. of Valparaiso, suffered less than either Santiago or
Aconcagua; but, at Casa Bianca, not a single house or wall of any
kind was left standing. At Mapel, the shocks were very severe,
great part of the village was destroyed, and a pool of water was
formed in the market-place. Quillota also suffered to a consider-
able extent, many houses were destroyed, and all were more or
less damaged. At Valdivia, in 39° 50'S, lat., one shock only was
felt; it is described as having been “ pretty sharp,”’ but it did no
damage. At the moment the shock was felt, two volcanoes in the
neighbourhood burst out suddenly with great noise, illuminated
the heavens and the surrounding country for a few seconds, and
then as suddenly subsided into their usual quiescent state.

‘“« Although no atmospheric changes appeared at the time of the
earthquake, there can be no doubt that very considerable changes
took place. ‘The weather, after the earthquake, continued as
usual; but on the evening of the twenty-seventh of November, just
eight days after the earthquake, the country, for a great extent,
was visited by a tremendous storm of rain, accompanied with heavy
gusts of wind; the rain continued all night, producing terror and
dismay among the people. Every thing saved from the earth-
quake, was exposed in the open air, or under such temporary
coverings as could be constructed with the few materials time and
circumstances permitted. Few of the tents, under which part of
the people lived, were water proof. Many were living in enclo-
sures called ramadas, made of dried boughs and bushes, open to
the heavens, and many had no other fence than could be formed of

Account of the Earthquake in Chili, 45

their furniture or other effects. Rain towards the close of the
month of Noveraber had been expected by no one, and no prepa-
ration to defend either persons or property from its effects, had
been made. Rain had never before fallen in the country, even at
a small distance north of the river Maule, in the month of No-
vember. The consequences anticipated from the rain, which, from
appearances, was likely to continue, were of the most distressing
nature. The total destruction of the houses which had been in-
jured, as well as that of the goods, merchandize, and furniture,
which had been collected, and of the growing crops, was antici-
pated by all. Its immediate effects, had it continued, would have
been intermitting and malignant fevers. These apprehensions
caused the people to pass a night of indescribable agony. The
rain, however, ceased suddenly towards morning, and the weather
‘became settled as usual.

“The greatest force of the earthquake appears to have been felt
at the distance of about fifteen miles N.E. of Valparaiso; the
whole country, from the foot of the Andes to far out at sea, has
been raised; the rise has, however, been very unequal.

“As the earthquake was felt at Copiapo in the north, and at Val-
divia in the south, its extent, from north to south, exceeded nine
hundred miles. Where the shocks were most severe, the earth
has been raised the highest, and its not subsiding again to its for-
mer level has probably been occasioned by the innumerable fissures
and multitude of small cracks caused by the repeated explosions,
by which the sanity of the whole mass has been somewhat al-
tered.

“ Many persons to the northward of Valparaiso thought the di-
rection of the shocks was from the south-west, while those to the
southward thought they came from the north-west. If the princi-
pal force, as it appears to have been, was exerted within a circle of
about fifty miles diameter, the centre of which was a little to the
__N.E. of Valparaiso, the direction of the shocks might have been, as
those at a distance, to the north and south of that space, have de-
scribed them. Most persons who live near the coast, suppose the
shocks to have come from seaward, either to the northward or

46 Account of the Earthquake in Chili.

southward, as had been mentioned, while those who resided
within the circle described, conclude they were produced by ex-
plosions, perpendicular to the earth’s surface. It does not ap-
pear that the earthquake extended into the mountains of the An-
des; no change whatever was observed in any of these mountains,
except as has been related near Valdivia, and here the voleanie
ridge is nearer to the sea and less elevated than in any other part
of Chili. The surface over which, or rather under which, the earth=
quake extended ashore, cannot be less than 100,000 square miles.

“‘ During the earthquake the sea, for a considerable distance along
the coast, receded and returned several times. At Quintero, the
fishermen who live upon the beach, fled in terror to the sand-hills.
At Valparaiso, a man-of-war’s boat, going ashore, landed at the
door of the Custom-house, which is twelve feet above the usual
high-water mark. Neither the recussion, nor the retrocession of
the sea, were as violent as might have been expected.

“Up to the end of September, 1823,the date of the last accounts,
earthquakes continued to be felt; forty-eight hours seldom passed
without a shock, and sometimes two or three were felt ving
twenty-four hours.”

Arr. VI. On Evaporation. By J. Frederic Daniell, ai
F.R.S., M.R.L., &c.
{Communicated by the Author.]
Tue subject of evaporation has occupied, at various times, much
of the attention of natural philosophers, and many accurate and
interesting observations have been recorded of the formation and
diffusion of elastic fluids, from various kinds of liquids. ‘The cir-
cumstances, especially, attending the rise and precipitation of aque-
ous steam in the atmosphere, are acknowledged to be important
in the highest degree, as upon their silent influence depends the
adjustment of those important meteorological phenomena, with
which is connected the welfare of all the organized creation. The
labours of De Lue, De Saussure, and particularly of Mr. Dalton,
haye thrown considerable light upon this neyer-ceasing process; but

Mr. Daniell on Evaporation. 47

something appears to be still wanting to complete the investiga-
tion, and to follow up the results to their ultimate consequences.
The following observations, however inadequate to fulfil this
desirable purpose, may possibly attract some attention to the sub-
ject, and may be the means of indicating the points which most
require elucidation.

_ It is a well-known fact that water, under all circumstances, is
- endued with the power of emitting vapour, of an elastic force
proportioned to its temperature. It is also well understood, that
the gaseous atmosphere of the earth, in some degree, opposes the
diffusion, and retards the formation of this vapour; not, as Mr.
Dalton has shewn, by its weight or pressure, but by its vis iner=
tie. What is the amount of this opposition, and by what pro-
gression it is connected with the varying circumstances of density
and elasticity, have never yet been experimentally explained.

It may facilitate the comprehension of the subject, to distinguish
three cases with regard to the evaporating fluid: the first, when
its temperature is such as to give rise to vapour equivalent in elas-
ticity to the gaseous medium, and when it is said to boil; the
second, when the temperature is above that of the surrounding
air, but below the boiling point; and the third, when the tempe-
rature is below that of the atmosphere.

_ With regard to the first, all the phenomena have been accurately
appreciated. The quantity evaporated from any surface, under
any given pressure, is governed, in some measure, by the in-
tensity of the source of heat, and is in no way affected by the
motions of the aérial fluid. The elasticity of the vapour is ex-
actly equivalent to that of the air, which yields en masse to its
lightest impulse. When disengaged, it is immediately precipi-
tated in the form of cloud, giving out its latent caloric to the
ambient medium; and under that form is again exposed to the
process of evaporation, according to the laws of the third division
of the process. All the phenomena attending the process of
boiling, have been ably investigated by Gay-Lussac, Dalton, Ure,
and Arch-deacon Wollaston; but, as they have but little con-
nexion with the atmospheric relations, which are the particular

48 Mr. Daniell on Evaporation.

object of the present paper, I shall proceed to the second case of
evaporation.

When the evaporating fluid is of a higher temperature than the
surrounding air, but not so high as to emit vapour of equal elas-
ticity to it, the exhalation is proportionate to the difference of tem-
perature. The gaseous fluid, in contact with the surface, becomes
lighter by the abstraction of portions of the excess of heat, and,
rising up, carries with it, inits ascent, the entangled steam. This,
as in the former case, is precipitated, and, in the form of cloud,
exposed to the third species of evaporation. This process is not
only proportioned to the difference of temperature, and the elasti-
city of the vapour, but is also governed by the motion of the air.
A current or wind tends to keep up that inequality of heat upon
which it depends, and prevents that equalization which would
gradually take place in a stagnant air. Such is the evaporation
which often takes place in this climate, in Autumn, from rivers,
lakes, and sea, and which is indicated by the fogs and mists
which hang over their surfaces.

It is, however, the third modification of circumstances, which
is the most interesting in the point of view which I have suggested,
and from which I have merely distinguished the preceding, to
free the subject from ambiguity. When the temperature of water
is below that of the atmosphere, it still exhales steam from its
surface; but, in this case, the vapour, neither having the force
necessary to displace the gaseous fluid, nor heat enough to
cause a circulation, which would raise it in its course, is obliged
to filter its way slowly through its interstices; and the nature of
the resistance it meets with in this course is the first object of
investigation.

The force of vapour, at different temperatures, has been deter-
mined with great accuracy, and the amount of evaporation has
been shewn to be ceteris paribus, always in direct proportion to
this force. The quantity is also known to depend upon the at-
mospheric pressure, but I know of no experiments which esta~
blish the exact relation between the two powers. I attempted to
elucidate the point as follows:—

Mr. Daniell on Evaporation. 49

By enclosing in a glass receiver, upon the plate of an air-pump,
a. vessel with sulphuric acid, and another with water, and by pro-
perly adjusting the surfaces of the two, it is easy to maintain, in
the included atmosphere of permanently-elastic fluid, an atme-
sphere of vapour of any required force; or, in the usual mode of
expressing the same fact, the air may be kept at any required de-
gree of dryness. The density of the air, in such an arrange-
ment, may, of course, be varied and measured at pleasure. Now
there are three methods of estimating the progress of evaporation
in such an atmosphere: the first, and most direct, is to weigh the
loss sustained by the water in a given time; the second, to mea-
sure, by a thermometer, the depression of temperature of an eva-
porating surface; and the third, to ascertain the dew point, by
means of the hygrometer.

Experiment 1.

The receiver, which I made use of, was of large capacity, and

fitted with a hygrometer. I placed under it a flat glass dish, of
74 inches diameter, the bottom of which I covered with strong
sulphuric acid.. The glass bell but just passed over it, so
that the base of the included column of air rested everywhere
upon the acid. In the centre of the dish, was a stand with glass
feet, which supported a light glass vessel of 2°7 inches diameter,
and 1:3 inches depth. Water to the height of an inch was poured
into the latter, the surface of which stood just three inches above
that of the acid. A very delicate thermometer rested in the water,
upon the bottom of the glass, and another was suspended in the
air. It may be necessary to observe, that the sides of the vessel
were perpendicular to its bottom, which was perfectly flat. The
height of the barometer was 29°6, and the temperature of the
water 56°. In twenty minutes from the beginning of the experi-
ment, the hygrometer was examined, and no deposition of mois-
ture was obtained at 26°.
This being the greatest degree of cold which could be conye-
niently produced by the affusion of ether, the experiment was re=
peated, with a contrivance which admitted of the application of a

Vou. XVII. E

50 Mr. Daniell on Evaporation.

mixture of pounded ice and muriate of lime, to the exterior ball of
the hygrometer. In this manner the interior ball was cooled to
0°, without the appearance of any dew. The temperature of the
water and air were, in this instance, 58°, and the pressure of the
atmosphere 30°5.

From this experiment it appears, that in the arrangement above
described, the surface of water was not adequate to maintain an
atmosphere of the small elasticity of °068 inch; in other words,
the degree of moisture in the interior of the receiver could not
have exceeded 129, the point of saturation being reckoned 1000.
How much less it was than this, or whether steam of any less de-
gree of elasticity existed, the experiment, of course, did not deter-
mine. We may reckon, however, without any danger of error in
our reasoning, that the sulphuric acid, under these circumstances,
maintained the air in a state of almost perfect dryness.

Experiment 2,

The same trial was made with atmospheres variously rarefied, by
means of the pump. No deposition of moisture was, in any case,
perceived with the utmost depression of temperature, which it was
possible to produce; and the state of dryness was as great, in the
most highly attenuated air as it was in the most dense. In the
higher degrees of rarefaction, the water however became frozen.

Experiment 3.

The water, which had been previously exposed to the yacuum of
the pump to free it from any air in solution, was weighed in a very
sensible balance, before it was exposed to the action of the sulphu-
ric acid under the receiver. Its temperature was 45°, and the
height of the barometer 30°4. In half an hour’s time, it was again
weighed, and the loss by evaporation was found to be 1'24 grains.
It was replaced, and the air was rarefied till the gauge of the pump
stood at 15-2; in the same interval of time it was re-weighed, and
the loss was 2°72, but its temperature was reduced to 43°. The
loss from evaporation, in equal intervals, with a pressure con-
stantly diminishing one-half, was found to be as follows:—

Mr. Daniell on Evaporation. 51

‘Temperature, Loss
Pressure Beginning Eud Grains

ee ee ee ee
es See ee en Me ee
ea as ee a ee ee
ete. ae ee er ae eee
ae ae a | ee
ce eae, Cee a eee ot ene
es ee ts ee ee ee

When the exhaustion was pushed to the utmost, the gauge stood
at 0°07, and the evaporation in the half hour was 87:22 grains.
During this last experiment, the water was frozen in about eight
minutes, while the thermometer under the ice denoted a tempera-~
ture of 37.

Now, before we infer from these experiments the state of evapo-
ration, from different degrees of atmospheric pressure, it is neces-
sary to apply to the results a correction for the variation of tem-
perature which took place during their progress. The quantity of
evaporation having been determined to be in exact proportion to
the elasticity of the vapour, we must estimate the latter from the
mean of the temperatures before and after the expcriments, and
calculate the amount for any fixed temperature accordingly. This
will, doubtless, give us a near approximation, although, from the
last experiment, we perceive that the method of estimating the tem-
perature of the surface water cannot be absolutely correct. The
following table presents us with the former results so corrected for
the temperature of 45°:

Pressure, Grains.

E12: Mem PE 1°24
LE i RTE RET aN 6
7°6 . . . . 5:68
3°8 . . . . 9°12
1:9, Sie Pie pale FRC u/s (piep,
96 ve), bolaiin ds 298d
Lf OS NE «Lae
sted ane het Oe

52 Mr. Daniell on Evaporation.

Notwithstanding the slight irregularity of the above series, we
can, I think, run no risk in drawing from it the conclusion, that
the amount of evaporation is c@éeris paribus in exact inverse pro-
portion to the elasticity of the incumbent air; and that De Saus-
sure was misled by his hygrometer, when he inferred from its indica-
tions, that a diminution of one-third the density doubled the rate.

Before we proceed, it is necessary to say a few words upon the
apparent discrepancy between the results of Mr. Dalton’s experi-
ments and mine, as to the amount of evaporation, at the full pres-
sure of the atmosphere. He found, upon the supposition of no
previous vapour existing in the air, that the full evaporating force
of water, of the temperature of 45°. would be 1:26 grains per
minute, from a vessel of six inches in diameter. This amount re-
duced in proportion to the squares of the diameters of the two ves-
sels, would give 7°65 grains in half an hour, from the glass of 2°7
inches diameter, which I employed. It must, however, be recol-
lected, that Mr. Dalton’s culculations were founded upon experi-
ments made at a temperature very considerably above that of the
surrounding medium, and that consequently a current must have
been established in the latter which greatly accelerated the pro-
gress. It is true, that he afterwards subjected his calculations to
the test of experience, at common atmospheric temperatures; but
then he expressly states, that ‘‘ when any experiment, designed as
a test of the theory, was made, a quantity of water was put into
one of them (vessels), the whole was weighed to a grain; then 7
was placed in an open window, or other exposed situation, for ten
or fifteen minutes, and again weighed, to ascertain the loss by
evaporation.” In this way he ascertained, that with the same
evaporating force, a strong wind would double the effect. The
difference, however, even after these considerations, is still very
striking; but, from several repetitions of the experiment, I have
no doubt of its exactness.

Experiment 4,

The arrangement described in the last experiment, having been
found adequate to maintain in the receiver a state approaching to

Mr. Daniell on Evaporation. 33

that of complete dryness, I had no opportunity of judging whether
the elasticity of the vapour, as it rose from the surface of the water,
varied in any degree with the pressure of the air, or whether any
part of the increase of evaporation were dependant upon such vari-
ation. To determine this point, I placed the sulphuric acid in a
glass, of the diameter of 2°8 inches, so that its surface was very
little more than equal to that of the water. The vessels were
placed, side by side, upon the plate of the air-pump, and covered
with the receiver. The temperature of the water and air was 52°,
and the height of the barometer 29°8. The following table shews
the dew point, which was obtained, at intervals of half an hour, at
different degrees of atmospheric pressure :—

Barom. ~— Temp. of Water and Air Dew Point

29 8

se SL agebllee been lla pics: ay, 2 apa teed cg:
~ ge nl they t all Sante © be gear aude tute
Oo tine dbinga ei 86 yee pepe nga

FLO mean i amie hari agate 7 nr arthaaneideert aterm barn 2
2 ne aga atte et 2 deter deter gamba
2A peta et atts ent aint, ylde ages pong

The differences of these results are so extremely small, and are
moreover so little connected with the variations of density, that
there can be no difficulty in regarding them as errors of observa-
tion, and we may conclude, that the elasticity of vapour, given off
by water of the same temperature, is not influenced by differences of
atmospheric pressure. The equal surfaces of sulphuric acid and
water here made use of, maintained, at the temperature of 52°, a
degree of saturation equal to 570. I repeated the experiment, at
the temperature of 61°, and the following are the results:—

Barom. Temp. of Water and Air Dew Point
29-6
12 ie) a a atl A ia a RS RS

Prgirivegay sow) © gipile, aagdgrgmaly: 96g
Gay Dank ey sien Barris Meals V6 gD
pepe el 30st) OPT yep gag
POA OLE HBO IN WA 4S Tike
PION ATS Var EB yt as

o4 Mr. Daniell on Evaporation.

Under these circumstances, the amount of saturation was 651;
an increase evidently dependant upon the force of the vapour, but
not in exact proportion to its augmentation.

Experiment 5.

Being now desirous of ascertaining in what degree the tempera-
ture of an evaporating surface would be influenced by differences
in the density of the air, I made the following disposition of the
apparatus:—To a brass wire, sliding through a collar of leathers,
in a ground brass plate, I attached a very delicate mercurial ther-
mometer; this was fixed, air-tight, upon the top of a large glass
receiver, which covered a surface of sulphuric acid of nearly equal
dimensions with its base. Upon a tripod of glass, standing in the
acid, was placed a vessel containing a little water, into which the
thermometer could be dipped and withdrawn by means of the slid-
ing wire. The bulb of the thermometer was covered with filtering-
paper. At the commencement of the experiment, the barometer
was at 30:2 inches, and the temperature of the air 50°. Upon
withdrawing the thermometer from the water, it began to fall very
rapidly, and in a few minutes reached its maximum of depression.
The following table presents the results of the experiment, for
different degrees of the air’s density; the intervals were each of
twenty minutes :—

Barom. Temp. of Air Temp. of wet Ther. Difference

1 a alt al dat tee: aia a ee al

LT ee ee, ae Ca ae

PA ee, FEOP (PO ER Re BRO AEG

Se a OS eee SO Aa See
1G 82? OY SR eo (See
oh: si: = Sola le Mian a ae ok yrs
Se RI Oe ot SSR ote

Here, in an atmosphere which a former experiment has proved
to be in a state of almost perfect dryness, we find that, at the full
atmospheric pressure, the wet surface of the thermometer was re-
duced 9°, It is worthy of remark, also, how small a quantity of
water is required to produce this effect. It has been previously

Mr. Daniell on Evaporation. 50

shewn, that a surface of 2:7 inches diameter, only lost 1:24 grains
in half an hour. This would have been 1:41 grains at the tempe-
rature of 490. The surface of the wet thermometer could not have
exceeded ;1,th of that of the evaporating vessel, and the maxi-
mum effect was produced in ten minutes, or 4 of the time, so that
the weight of water evaporated in this case was not more than
(:0094 grains) one-hundreth of a grain. It will be seen, that the
depression increased with the rarefaction of the air, but in the pro-
portion only of the terms of an arithmetical progression to those of
a geometrical. The increase is attributable, not to the augmented
quantity of the evaporation, but to the decreased heating power
of the atmosphere. MM. Du Long and Petit, in their experi-
ments upon the cooling power of air, determined it to be nearly
as the square root of the elasticity; but whether the heat which it
is capable of communicating to a cold body, follow the same pro-
gression, the experiments above detailed are not sufficient to de-
termine with precision, We may, however, certainly conclude
from them, that the temperature of an evaporating surface is not
affected by the mere quantity of evaporation.

It is right to remark that, in the last experiment, care was
always taken to station the evaporating thermometer in .the same
place in the receiver, for I found that, when the air was highly
rarefied, a greater degree of cold could be produced by approxi-
mating the wet bulb to the surface of the acid. No difference,
however, could be perceived from such a change at the full atmo-
spheric pressure. I also ascertained that no change of relative
position in the surfaces of the acid and water produced any al-
teration in the dew point under any circumstances.

_ The few simple facts above determined appear to me to be in-
timately connected with the solution of some very important at-
mospheric phenomena, and I shall endeavour briefly to indicate
their relation.

_ The aqueous fluid is so abundantly spread over the face of the
earth, that there can be no doubt that the permanently-elastic
atmosphere, which surrounds it, would very speedily be saturated
With its steam, did notgome cause, analogous to the sul phuric acid

56 Mr. Daniell on Evaporation.

in the receiver, prevent its universal diffusion. This never-failing
cause is inequality of temperature. As in the small experiment
we found that the degree of dryness was proportioned to the energy
of the absorbent mass, and that the existing vapour was equally
diffused between it and the exhaling surface; so, in the larger
operations of nature, we shall find that the state of saturation is
dependant upon the point of precipitation, and that the aqueous
atmosphere is nearly uniform between it and the source of steam.
Now, it is well understood that the temperature of the gaseous
atmosphere in its natural state must decrease with its density as
we ascend to its upper parts; so that a great degree of cold is at
all times to be found within a very moderate distance from the
surface of the waters. It is this low temperature which determines
the tension of the aqueous atmosphere ; and it is evident that the
evaporation which is thus caused at the base of the aérial fluid,
must be accompanied by a simultaneous and equal precipitation
above. What then becomes of the precipitated moisture? Let us
endeavour to trace the order of this phenomena. We will first
suppose a calm state of the atmosphere, a temperature of 80°, and
the barometer at 30 at the surface of the earth. By a calm state of
the atmosphere is here meant, one that is free from any lateral
wind, and in which, the only currents being in an ascending and
descending direction, evaporation would proceed at the rate ex-
hibited in the first column of Mr. Dalton’s table. The dew-point
at the surface of the earth is 64°, and this is determined by the
temperature at the height of about 5000 feet, where the barometric
column would maintain itself at 24 inches. The degree of satura-
tion below would therefore be 600, and the amount of evaporation
1-74 grains per minute from a surface of six inches diameter.
This quantity we therefore suppose condensed at the height before
named. But the state of saturation in the atmosphere, above this
point of precipitation, is again diminished; for we may suppose the
force of the vapour to be determined by a temperature of 31° at a
height of 15,000 feet, where the barometer would stand about 16
inches. ‘The force of evaporation would, therefore, be 1.71 grains
per minute, at the full atmospheric pressure ; and this amount

Mr. Daniell on Evaporation. 57

increasing as the pressure diminishes, would give 2°13 grains per
minute ; so that the power of evaporation at this stage exceeds the
supply of moisture, and no cloud could possibly be formed.
Above the second point of condensation let us now suppose the
force of the vapour to be determined, in still loftier regions, by a
temperature of 120. The force of evaporation would then be 0°44
grains, increased in the proportion of 16 inches to 30, or 0°82
grains. Here, then, the power of evaporation would be insufficient
to diffuse in the upper regions the whole of the moisture supplied
from the surface of the earth, and a cloud, it might be supposed,
must consequently result. But another modification of the pro-
cess now ensues; the precipitated moisture has a tendency to fall
back into the warm air below it, and consequently would again
assume the elastic form with a rapidity proportioned to the rare-
faction of the stratum in which it is diffused. There is, I think,
no difficulty in supposing that no visible cloud, or one of extreme
tenuity, would be formed during this double process of evapora-
tion. A yery important re-action, however, must take place upon
the strata of vapour beneath; the elastic force being increased
aboye, enables the water below to maintain an atmosphere of a
higher degree, and the quantity of evaporation must decrease as
the point of saturation rises. A different arrangement of the points
of precipitation would ensue in the progress of these effects.

An important distinction must here be drawn between the ulti-
mate effects of the superior and inferior evaporation denoted above.
In the first, the whole weight of water is condensed and simul-
taneously exhaled ; and although it constitutes steam of an in-
ferior degree of force, there is little or no difference in the quantity
of its latent heat, and no effect is tierefore produced upon the
temperature of that portion of the atmosphere in which the change
takes place. But in the second, the condensation happens at one
spot, and the vaporization at another inferior to it; the latent heat
is therefore evolved at the former and communicated to the air,
while at the latter the process is reversed, and the air is cooled.
The process of this operation would, therefore, tend to equalize
the temperature of the atmosphere,

58 Mr. Daniell on Evaporation.

We will next imagine that the surface of the earth is swept by a
high wind, and that the atmosphere instead of resting calmly upon
its base, moves laterally with great velocity. Under these cireum-
stances experience has shewn that the amount of evaporation will
be nearly doubled; but the force of evaporation is not altered in
the upper regions. The inferior exhaling surface being immove-
able, the motion of the air perpetually changes, and renews the
points of contact, and prevents accumulation at any one place;
but in the heights of the atmosphere the exhaling surface of the
cloud is borne upon the wind, and their relative situations never
change.

The progress of precipitation must, therefore, necessarily, under
these circumstances, outstrip that of evaporation, and the dis-
turbance of the atmospheric temperature will be greatly accele-
rated.

There is another cause which would also quicken evaporation
below, without equally increasing its power of diffusion at any
given height above; and that is a decrease in the density of the air
at the surface of the earth. Under the circumstances of our first
supposition imagine the barometer to fall to 28 inches, the evapo-
ration would be increased from 1°74 grains per minute, to 1°86
grains; but this decline of two inches at the surface would indi-
cate a contemporaneous fall of little more than one inch at the
height of 15,000 feet, and the rate of diffusion would vary accord~
ingly. When it is considered that great falls of the barometer are
generally accompanied by high winds, and that this disparity is
multiplied by the force of the current, it is easy to appreciate the
influence of this local increase of the power of evaporation.

The facility of evaporation in the rarer regions of the atmosphere
will also go far to account for the state of saturation in which the
air of mountainous countries is generally found, and many minor
meteorological phenomena might probably meet with their expla-
nation from variations of the same cause; such as the fogs which
frequently accompany a very high degree of atmospheric pressure,
and that peculiar transparency of the air which often precedes |
yain, and is accompanied by a falling barometer, But te return

Mr. Daniell on Evaporation. 59

again to the more general and extended influence of the vapour
upon the boundless strata of the atmosphere :—that the phenomena
of evaporation and condensation, as we have been contemplating
their progress, have not been described with any bias to theoreti-
cal considerations, but are in strict accordance with facts and ob-
servations, any one might easily convince himself with less diffi-
culty than would at first be supposed. To prove the assertion I
shall extract the following passages from the works of De Luc,
who was probably one of the most accurate observers of nature
that ever existed, and who seldom, indeed, allowed any hypothe-
tical considerations to warp his description of what he had ob-
served. They will afford a complete illustration of the preceding
remarks, although they were penned by him to support a very
different hypothesis.

“Si Von ne fait qu’une légére attention a la surface de ces
brouillards vus des montagnes pour en jouir comme d’un beau
spectacle, on peut penser qu’ils sont permanens ; que l’évaporation
est arrivée 4 son maximum 4 la surface des eaux, parce que l’air
est parvenu 4 l’humidité extréme ; et que les vapeurs vesiculaires
qui troublent la transparence de cet air restent les mémes durant
des semaines ou méme des mois; cest-a-dire, tant que le bro-
uillard se conserve 4 une méme hauteur. Mais le phénoméne
différe beaucoup de cette premiére apparence: l’evaporation con-
tinue 4 la surface des eaux, les vapeurs vésiculaires qui s’en
forment montent sans cesse et une nouvelle évaporation a lieua
Ja surface des brouillards. C’est un spectacle aussi amusant
qu'instructif, que celui que fournit cette surface, vue d’un lieu peu
élevé audessus d’elle, et dans une grande vallée ou l’on ait A
quelque distance, des montagnes rembrunies par des foréts de
sapins. Une telle vallée éclairée par les rayons du soleil semble
étre comblée de coton, filé dans toute sa surface par des étres
invisibles en fils invisibles: il s’y fait par-tout des tumeurs, sem-
blables a celle que produit une fileuse sur sa quenouille en tirant
Je coton pour former son fil, et elles disparoissent successivemeng
en se dissipant dans Pair. Quelquefois ces tumeurs s’allongent et
fe separent de la masse en tendant & monter; on les voit alors

60 Mr. Daniell on Evaporation.

s’étendre comme un paquet de gaze qui se déploie et peu a peu
elles disparoissent. Les brouillards se forment done constamment
2 la surface des eaux et du sol; mais constamment aussi ils se
dissipent dans I’air supérieur: et cependant on n’appergoit point
que l’humidité y augmente.”—TJdées sur la Metéorologie, Tom. 11,
p. 78.

“‘ Depuis que mes idées ont changé sur la cause de la pluie, j’ai
fort souvent fixé mon attention sur les nuages et j’ai reconnu trés
évidemment, qu’ils s’évaporent méme tandis qu’ils grossissent. Si
l’on fixe ses regards sur leur bord découpé qui, lorsqu’il a pour
fond l’azur du ciel, presente mille figures singuliéres, celles que
V’'imagination leur préte alors, peut aider 41’examen dont je parle,
en rendant leurs changemens plus frappans. II arrive souvent,
que la partie sur laquelle on fixe son attention se dissipe au lieu
méme ov l’on a commencé a I’cbserver: souvent aussi on la voit
s’étendre, sans que la totalite du nuage se meuve, et elle ne se
dissipe pas moins durant cette extension. Quelquefois, tandis
que l'un des festons du nuage se dissipe on en voit d’autres se
former, s’étendre, produire eux-mémes de nouveaux festons ; par
ou le nuage grossit: d’autres fois il diminue; et alors tous ses
festons s’évaporent successivement et il n’en acquiert de nouveaux,
que parcequ’il se découpe : on appercoit en méme tems, qu'il devient
plus mince et il disparoit enfin totalement.

“ C’est ce qui m’a conduit a penser qu’il y a en effet dans Vair,
une source générale de vapeurs qui en fournit en certaines circon=
stances; que ces vapeurs sont produites au lieu meme ou se
forme un nauge; que c’est par la durée de cette production de
vapeurs, que les nuages subsistent, s’aggrandissent méme,
quoiqu’en s’évaporant tout le tour; et que lorsqu’ils se dissipent
c’est que leur evaporation n’est plus réparée par la formation de
nouvelles vapeurs.”—J0. p. 117.

I shall now conclude this paper with an observation which is in-
timately connected with the subject of the preceding pages. It
has been argued that the quantity of heat which would be commu-
nicated to the air by the condensation of atmospheric vapour
would be trifling, and inadequate to produce those expansions in

Mr. Daniell on Evaporation. 61

the aérial currents to which, in my essay upon the constitution of
the atmosphere, I have ascribed the fluctuations of the barometer.
Now, I have therein shewn how the gradual spread of a small in-
crease of temperature, through a considerable stratum, is sufficient
for the purpose ; and a very little consideration will, I think, con-
vince any one that the evolution of caloric is by no means so small
as has been supposed.

‘The following rough calculation will place the facts in a striking
point of view :—The latent heat of steam has been proved to be
somewhere about 970°, and it is known that, whatever be its den-
sity, or the temperature at which it is produced, the amount will
differ but little from this estimate. The condensation, therefore,
of a pound of steam of any degree of elasticity would be adequate
to raise a pound of water 970°. The capacity of atmospheric air,
of mean density, for heat, compared to that of water, is as ‘2669
to 1; therefore the same quantity of heat which would raise a
pound of water 1°, would raise a pound of air 3°7. The conden-
sation of a pound of steam would, therefore, elevate the same
weight of air to 3589°. A pound of air is equal to about 11 cubic
feet, so that the evolution of heat from the condensation of a
pound of steam, would be sufficient to raise the temperature of
3657 cubic feet of air 10°.

When we now look to the depth of water which falls upon the
surface of the earth, and recollect that this is not the sole measure
of the effect we are endeavouring to estimate, but that the unceas-
ing precipitation and exhalation of the clouds is perpetually ex-
tending this influence to the most inaccessible heights, we shall,
perhaps, have a juster notion of the prodigious power of atmo-
spheric vapour ; and it will, I think, be granted that I have not
over-rated the impulse which it is calculated to impart.

62 _ Mr. Ware’s Design for

Arr. VII.—A Design for making a Public Road under the
Thames, from the east side of the Tower, near Iron-Gate
Stairs, to the opposite side of the River, near po one
down Stairs. By Samuel Ware, Esq.

[Communicated by the Author.]

The carriage-road . . . 28 feet wide.
Internal Dimensions | The height above the road . 18 feet.
of the The foot-paths . . . . 14 feet wide.
Arche The greatest width . . . 42 feet.
The greatest height . . . 21 feet.

The following particulars of the Esrrmare describe the mode of
erecting the arch-way :—

Compensation for the ground and buildings on the north
side of the river, and for the ground and buildings on
the south side, to form the approaches; cofferdams, in
ten successive lengths or removes, to keep out the
water; and strutting, to keep up the ground.

Steam-Engines, to keep the works within the cofferdams
dry, and subsequently for draining the’ road, should
there be occasion.

Digging out a channel, in the bed of the river, for the
arch-way, and the ground for the approaches.

Removing the refuse earth ; claying, filling in, and level-
ing, two feet above the extrados of the arch.

Yorkshire Ledgers for the foundations of the arch-way,
and walls of the approaches and embankments, and
piling as occasion may require.

Stone-work, cut in voussoirs, of the arch, and counter-
arch.

Lining with lead, 10d. to the foot superficial, enveloping
these arches.

Super-arch of brick-work, lined externally with tiles in
cement. ‘

a Public Road under the Thames. 63

Centering for the arches.

Forming and gravelling the road, ascending one foot
. perpendicular to twenty feet horizontal.

Drains, pipes, foot-paths, and lamps.

Embankments, and other walls and parapets, in the ap-

proaches *.

Facings to the entrances to the arch-ways, and toll-

_ houses.

Estimated amount of the above works .... . £250,000

Pecuniary Advantages.

A small part of such a revenuet, as would be derived from the
number of passengers and carriages which has been estimated to
pass London Bridge daily, calculated at the tolls allowed to the
Southwark Bridge Company, would be ample to compensate the
cost of this arch-way.

The taxes arising out of the materials of the buildings likely to:
be erected, together with the assessed taxes arising out of them
when built, in the ways to and through the lower road to Deptford,
and in communicating with the Kent Road, consequent on such a
connexion between the two sides of the Thames, would be a great
source of revenue to the government, probably more than sufficient
to compensate the cost of this arch-way.

* This mode of approach is also applicable to a road descending from a
bridge ; is cheap, by lessening the expense of compensation for the buildings
and ground required and damaged in making an inclined plane ; and is con-
venient, because the foot of the inclined plane is at the river.

Y BRIDGES. Average|Toll| £. 5.
London Biackfriars Westminst. d,

+ Foot Passengers - - 7 ¢| 89640 | 61069 |. 37820 | 62813 | 1 | 261 17

Waggons - - - - - -- 1s 769 533 173 492] 12] 24 12
Carts and Drays - - - la 2924 | 1502 963 | 1796] S|] 52 17
Coaches ------- 1240 990} 71} 1133] 9] 42 9

wo
Gigs and Taxed Carts | 3] 485] 500} 5669] 518] 4] 8 12
Horses not drawing - 2 & 764 522 615 633 | 14 3 19

a See Month. Mag. March, 1816, and Morn, Chron, May 26, 1812.
6 £400 per day, or £146,000 per annum,

64 Mr. Ware’s Design for

The saving in time, and in the wear and tear of carriages, horses,
and men who would otherwise go over London Bridge, or cross
the river in boats, would be a compensation for the tolls to be paid
at this arch-way.

The carriages and passengers are those coming from the streets
adjacent to the site of the proposed arch-way, those going into or
through Surrey from the East India, West India, and London
Docks, from the Commercial Road, and from the Counties of Hert-
ford, Cambridge, Norfolk, Suffolk, and Essex ; also those going
to the above-mentioned places from the counties of Surrey and
Kent.

The necessity of increasing the width of the intended new Lon-
don Bridge, by this diminution of the number of passengers and
carriages, may be obviated, and a large sum of money thereby
saved. .

Political Advantages.

The communications, by this road, between the officers of govern-
ment, and the Mint, Trinity-House, Custom-House, and the 'Tower,
may be facilitate d.

A readier transfer of soldiers, arms, and stores, to and from the
counties north and east of London, and the Tower, to and from
Woolwich, Chatham, and Sheerness, by land, will be obtained by
this arch-way.

This arch-way may be made a military pass, there being pro-
posed a private way to it from the Tower.

Observations.

It seems remarkable, considering the great advantages to be
obtained in populous cities by opening a communication between
the shores of a navigable river, for foot-passengers, horses and
carriages, without interrupting the navigation on the river, that the
passage under the Euphrates, constructed by Semiramis, at Baby-
lon, is the only one upon record. The account Diodorus the Sicilian
gives of it may be translated thus :—

“In the low ground of Babylon, Semiramis sunk a square pond,
35 feet deep, each side being 300 stadia in length, the banks

a Public Road under the Thames. 65

whereof were lined with bricks well cemented with bitumen *, she
then turned into it the water of the Euphrates t. Across the chan-
nel of the river, thus made dry, she then made a passage in the
nature of a vault from one palace to the other. The arch was
built four cubitst thick, of firm and strong bricks, plastered all
over on both sides with bitumen. The walls supporting the arch
were 20 brick § in thickness, and 12 feet high from the floor to the
springing of the arch, and the breadth of the passage was 15 feet.

* Dr. Hulme, (Archzologia, vol. xiv. page 57,) analyzed the cement adher-
ing to a brick brought from Babylon, and found it to be bitumen.

+ Strabo, (lib. xvi. page 738,) states the width of the Euphrates to be one
stadium, which is generally taken at a furlong, or 660 feet. M. Gosselin
shows that there were two stadia; one used by Herodctus, called the short
stadium, about 329 feet English: the other of Archimedes, about 438 feet
English. Ctesias, from whom Diodorus had his account, used the stadium of
Archimedes, Herodotus used the short stadium. In this way the discordance
of Herodotus and Ctesias, in respect to the wall of Babylon, has been re-
conciled.

$A cubit royal of Babylon was estimated, by Romé de Lille, at 22575
inches English.

§ There is a brick in the British Museum, brought from the site of ancient
Babylon. That described by Dr. Hulme, in Archzologia, vol. xiv. page 55,
is 133 inches square, and 3 inches in thickness, and weighs 38 1b. 11 oz. avoir-
dupois. He analyzed the material, and found it to be pure clay, and not
burnt.. Dr. Henley, in the same volume, page 205, deciphered the inscription
on it, “ a brick baked by the sun.” Pocock measured some of the bricks of
the brick Pyramid at Saccara, built by king Asychis ; he found some 133
inches long, 6% broad, and 4 thick ; and others 15 inches long, 7 broad, and
4} thick.

In Rennel’s Geo. Sys. of Hero, section 14, page 356, is the following note :
© Diodorus describes a vaulted passage under the bed of the Euphrates, by
which the Queen Semiramis could pass from one palace to the other, on dif-
ferent sides of the river, which was a stadium in breadth, (according to Strabo,
page 738,) without crossing it. This serves, at least, to show, that the palaces
were very near the river’s banks.”

“ Ata time (1800) when a tunnel, of more than halfa mile in length, under
the Thames (at Gravesend) is projected, it may not be amiss to mention the
‘ reported dimensions of the tunnel made by Semiramis, under the Euphrates ;
which, however, was no more than 500 feet in length, or less than 1-5th of the
projected tunnel under the Thames. That of Semiramis was said to have been
15 feet in breadth, 12 feet in height to the springing of the arch, perhaps 20 in
all. The ends of the yault were shut dp with brazen gates, Diodorus had an

Vou, XVI. r

66 Mr. Ware’s Design for

This work was finished in 260 days, and then the river was turned
into its ancient channel; so that Semiramis could go privately
from one palace to another, under the river. She made also two
brazen gates at each end of the vault, which continued to the time
of the kings of Persia, the successors of Cyrus.”

In 1798, atunnel, 900 yards in length, was projected to pass
under the Thames, to unite Tilbury, in Essex, with Gravesend, in
Kent, at an estimate of only £15,955. Subscribers were obtained
to promote the undertaking, by whose means an engine-house and
steam-engine were erected, and a shaft dug, about 146 feet deep,
when the engine-house was burnt, and the operations were aban-
doned.

In 1805, an Act of Parliament (45 Geo. 3. cap. cxvii.) was
obtained, to construct a tunnel under the Thames, at the Old
Horse Ferry, about 23 miles below London Bridge, and to raise
£140,000, and a further sum of £60,000, in all £200,000. A
shaft, 76 feet deep, was sunk, and a driftway, 5 feet high,
3 feet wide at the bottom, and 2 feet 6 inches at the top, was
extended, under the direction of Mr. Trevetheck, a Cornish
miner, 1011 feet from the south shore, under the bed of the
Thames, when sand and water burst in upon the workmen,
and further progress was suspended. The powers given by this
act are now, by lapse of time, void. In 1809, notice was given,

idea* that the Euphrates was 5 stadia in breadth, see lib. ii, c,1. The Eu-
phrates was turned out of its channel, in order to effect this purpose. Hero-
dotus, who is silent concerning the tunnel, says, that the river was turned
aside in order to build a bridge. Diodorus describes a bridge also. ‘here is
an absurd story told, in both these historians, respecting the disposal of the
water of the river during the time of building the bridge. According to them,
the water was received into a vast reservoir, instead of the obvious and usual
mode of making a new channel to conduct the river, clear of the work con-
structing in its bed, into the old channel, at a point lower down t.”

* Diodorus merely states, that the bridge built by Semiramis was 5 stadia in
length. Bridges are frequently five times aslong as the width of the river
they stride.

+ This story, from the vastness of the reservoir, may be true. Local circum:
stances may have compelled Semiramis to adopt this apparently extrayagant
mode of removing the water of the Euphrates from the site of the tunnel.

- a Public Road under the Thames. 67

by public advertisement, that the directors were desirous of re-
ceiving designs for proceeding again in this work, and they offered
a premium of £200 for the plan which should be adopted, and a
further premium of £300 upon the execution of it. Since that
time the project has lain dormant. Lately a pamphlet has ap-
peared, entitled “ A New Plan of Tunnelling, calculated for open=
ing a Road-way under the Thames, by M. T. Brunel, Esq., in
order to the raising a capital of £ by transferable shares of
£100}each,” for commencing again this project. Mr. Brunel
describes his plan as follows: ‘* The character of the plan before
us consists in the mode of effecting this excavation by removing
no more earth than is to be replaced by the body of the tunnel,
retaining thereby the surrounding ground in its natural state of
density and solidity.”

Mr. Brunel proposed that the excavation, 34 feet wide by 18
feet high (external dimensions), consisting of 33 such drift-ways
as that before mentioned, moving simultaneously, worked by 33
men, at the rate forward of three feet per day, followed by a brick
tunnel at the same pace, should pass in a stratum which he states,
* has been found to resist infiltrations,” so that the crown of the
tunnel will have a head of earth on it, from 12 to 17 feet in thick-
ness, quite undisturbed, as he expects.

' The method proposed by Mr. Dodd, at Gravesend, by Mr. Vazie,
at Rotherhithe, and by Mr. Brunel, is by mining. Other methods
may or have been proposed, such as to dredge out a channel in the
bed of the river by machinery in vessels, and afterwards to sink
therein caissons with brick or stone tunnels in them, to be after-
wards secured together and perforated; or to sink large iron cy-
linders or boxes, the size of the proposed tunnel, with moving,

lapping, and closing joints, let down, one after another, on strong

iron mooring chains, into the channel so dredged out; the junc-

tions to be facilitated by means of the diving-bell: but these

schemes are of a very adventurous character, and might be tried

perhaps with propriety in the case of a small passage under a

river, The apparent cheapness of such methods seems calculated
F2

68 | Mr. Ware’s Design for

to obtain subscribers to such a project, but not to effect a dry and
secure passage for men and carriages under the Thames.

The method of Semiramis was simple in design and certain of
success. Troughs holding water, such as the canal aqueducts
over rivers, are to be seen in all parts of the country; and there
can be no doubt, that such an arch-way as that before described *
in the estimate commencing this statement, executed in the open
air, and uninterrupted by water during such erection, by means of
cofferdams, would have a successful issue, and be perfectly dry
under a river, for a thoroughfare for passengers and carriages.
In modern times, a cheaper way of rendering the bed of a river dry
has been discovered than that of Semiramis, which was by means
of a reservoir to receive the waters of it, or even than that of Trajan,
in building the bridge across the Danube, which was by making a
temporary new channel to receive its stream. We have lately seen
the piers of Waterloo Bridge and of Southwark Bridge laid dry, in
the bed of the Thames, by means of cofferdams, the use of which,
in keeping the space enclosed in them free from water, has been
greatly extended by the facility obtained by means of steam-
engines; and by similar means may an arch-way be constructed
of almost any useful dimensions under the river, and with the
same success, and not with more interruption to the navigation of
the Thames than would be caused by one of the vessels in the pool
getting athwart the stream, and remaining so for a few months.

Since the foregoing statement was made, an advertisement has
appeared of the intention of applying to Parliament for leave to
bring in a bill to erect a patent wrought-iron bar bridge of sus-
pension, from some part of the parish of St. Botolph, Aldgate,
over the Thames, to some part of St. Mary, Bermondsey, of such

* The following account of the suspended gardens of Nebuchadnezzar, at
Babylon, extracted from Diodorus, will show the care used by him, to render
the rooms under them dry. ‘ On the walls were laid stones, 16 feet long and
4 feet broad ; these were covered with reeds coated with brimstone, on which
were laid double tiles, cemented together, and on them were laid sheets of
lead.”,

a Public Road under the Thames. 69

a height as to admit vessels to pass under it at prin: tides, pith
out lowering their masts.

These repéated attempts to obtain a road-way for passengers and
carriages eastward of London Bridge, across the river, together
with the almost impassable state of London Bridge, from the
crowds on it, in the middle of the day, show that there is a demand
for such a communication between the sides of the Thames, east=
ward of London Bridge. The questions to be considered, are, First,
what method of obtaining such an object is the best? Secondly,
how that method can be carried into effect with certainty? Thirdly,
what is the best site for sucha road-way? Fourthly, whether such
a work, in the site hereby laid down, would not be of such political
importance, facilitated as the execution thereof would be by a
possession of the ground necessary for the northern approach, as
to warrant the State in undertaking the work, leaving to the public
the use, subject to certain tolls and restrictions, as may accord
with the uses of it by Government? Fifthly, as to time, should
the cofferdams necessary to resist the deep water in the erection of
the new London Bridge be of such a size as to cause an impetus to
the river, or alteration of the mid-stream, so as to destroy the pre-
sent bridge, or render it impassable, (it being intended that it shall
remain until the new one is passable), would not then such a way
as the one hereby proposed be a great relief to Southwark
Bridge, until a temporary bridge be supplied? And, comparing
generally the expediency and cost of carrying into effect this design
with the expediency and cost of rebuilding London Bridge *, ought
not this work to have the precedence ?

SAMUEL WaRE.

5, John Street, Adelphi. .

* See this Journal of Science, Roy. Inst., Nos. 29, 30, and_3], 1823; and
Tracts on Vaults and Bridges, 1822,

70

Art. VIII. An Account of ihe Overflowing Well in the
Garden of the Horticultural Society at Chiswick. (Com-
~ municated by Joseph Sabine, Esq., S.H.S. &c.),

[The specimens adverted to in the following paper are deposited in the
Mineral Room, at the Royal Institution. ]

In consequence of the success which had attended the opera-
tions of several persons in the vicinity of Chiswick in boring for
water, it was determined by the Council of the Horticultural
Society that an attempt to procure an overflowing well should be
made in the society’s garden, for the purpose of obtaining a supply
of water for various purposes; but more particularly to form an
ornamental canal in the Arboretum for the growth of hardy aquatic
plants.

After the necessary inquiries had been made, it was determined.
that Mr. John Worsencroft, a person who had previously suc
ceeded in making an overflowing well for Messrs. Bird, of Ham-
mersmith, should be empioyed to execute the experiment. He
commenced his operations upon the first of September last; and
after boring for five weeks without material interruption, tapped
the spring on the 18th of October, and finally completed his task
on the following day. The depth from which the water first rose
was 317 feet, and the whole depth of the well, when completed,
was 329 feet; the additional 12 feet of boring having been made
in order to gain a perfect opening into the bed of the spring, which
flowed when first tapped less copiously than after the final depth
was obtained. The chalk from which the water immediately comes
is soft, but the bottom of the well is in hard chalk. The water in
all the neighbouring wells appears to have been obtained at about
the same depth; and the strata through which the perforations
were made are nearly similar to those met with in the present
instance,

The tackle and instruments used were very simple. A scaffold-
ing was raised 20 feet above the proposed orifice of the well, on
which a platform was fixed to support a windlass, by which the

Overflowing Well at Chiswick. 71

rods used in boring were lowered into, and raised from, the well.
These rods were of tough iron, about an inch and a half square,
and ten feet long ; the ends of each screwing on to, or unscrewing
from, the top of the next, as they were lowered into, or raised
from, the hole. The instruments fixed as occasion required to the
lowest extremity of the series of rods when in action, were augers
of various dimensions for boring, steel chisels for punching, and
a hollow iron cylinder, (called a shell,) fitted with a valve at its
lower end, for bringing up soft mud. The rods, when an auger
was attached to them, were turned round by means of moveable
arms or dogs, which were made to lay hold of the part of the
uppermost rod at the top of the hole; the auger being thus
forced through the stratum of clay or sand, was drawn up as soon
as its cavity was filled with the substance it had loosened. The
chisels were employed for punching through stones, hard sub-
stances, or hard chalk ; the rods, when these were attached, were
moved by means of a powerful beam acting as a lever, and worked
by four men.

The water is discharged at the surface of the ground after the
rate of six gallons per minute, and is capable of being carried
20 feet above the ground level; and even then supplies a copious
stream. The well is lined for the first 186 feet with cast-iron
pipes, with a three-inch bore, jointed by means of wrought-iron
collars, which are rivetted into the pipes; the succeeding 77 feet
6 inches are lined with copper pipes, with 23 inches bore, soldered
into a single length, and resting in the chalk, through which the
remainder of the hole is bored, and in which no pipes were used.
The whole series of pipes was introduced at once, the hole having
been prepared for receiving them as soon as it avas ascertained
that the augers had reached the chalk stratum. The land
springs in the gravel, above the blue clay, were kept out in the
first instance by extra iron pipes. The spring which was found
in the sand below the blue clay, and above the chalk, rose to
within a few fect of the surface, but did not overflow. The whole
of the water of this spring is, however, excluded from the well by
the pipes with which it is lined,

a2 Mr. Sabine on the

The cost of the well, including that of the pipes, boring; and
every other expense whatever, did not exceed 130/.; and the’
manner in which it was executed, was, in every respect: satisfac-
tory. Indeed it is impossible to speak too highly of the care,
attention, and dexterity of Mr. Worsencroft, and the workmen:
whom he employed.

Turnham Green, November 27, 1823.

Memoranda of the various strata bored through.
Feet.

19 Gravel.

162 Blue clay. Specimen No. 1. At the depth of 59 feet from
the surface asmall stone, sp. No. 2, four inches thick was
found; another at 149 feet was found six inches thick,
but it was pounded to dust by the chisel ; a third was
found at the depth of 153 feet; it is marked sp. No. 3.
At 162 feet from the surface the clay became veiny, and
intermingled with very minute glittering fragments; this
is sp. No. 4. At 173 feet the clay became more sandy,
sp. No. 5, and continued so ull it altered into the next
kind.

30 Coloured clay; varying from brick-red, mixed with blue and
yellow, to many shades of dull purple ;. sp. 6, came from
190 feet; sp. 7, from 200 feet; sp. 8, from 203 feet;
sp. 9, from 211 feet, when the seam changes into the next
which is more yellow.

22 Clay, with nearly an uniform colour of yellow ochre, occa~
sionally mixed irregularly with grey. Sp. 10. This was
more sandy than the previous stratum. Among this water
rose in some quantity.

28.6 Soft soil, apparently composed of clay and sand. It varied
very much in colour, being sometimes bright green, other-
wise yellow intermixed with green, or sometimes beauti-
fully veined with dark red and yellow. Many specimens
are sent, v2z. : :
sp. 11, 240 ft. sp. 12, 242 ft. sp. 18, 248 ft.
sp. 14, 244 ft. sp. 15, 246 ft. sp. 16, 246 ft.
sp. 17, 247 tt. sp. 18, 2565 ft. sp. 19, 261.6 ft.

Overflowing Well at Chiswick. 73

» The last specimen is of the soil immediately above the chalk.
' Two stones were met with in this stratum; one like those
formerly mentioned, of which no specimen could be pre~

| served; the other a flint, sp. 20, at 257 feet.

67.6 Chalk; among which many flints were scattered. Of these,
one, sp. 21, was one foot in thickness, and so unusually
hard’ as to occupy the workmen three days in punching
before they could force a way through it. The water was
found at the depth of 317 feet, in a bed of soft chalk,
mixed with small flints; the hole was bored 12 feet among
the water, so that the total depth of the well is 329 feet ;

/ and it is supposed by the workmen that the last piece of
chalk that was brought up sticking to their punch, was
from the upper surface of a new layer of chalk in which
there is no water. Specimen 22, is a morsel of a hard
stone, apparently containing ore, which was brought up
in the auger from among the chalk, at the depth of 274
feet. Specimen 23, is of the first chalk which was found
at 261.6 feet. -Specimen 24, is from 317 feet, when the
first water was found; it was saturated with moisture
when first brought up; sp. 25, is the last piece of chalk
brought from 329 feet, and supposed by the workmen to
be from the upper surface of a new and dry layer of chalk ;
sp. 26, various fragments of large flints broken by the
punch at different depths in the ground ; sp. 27, morsels
of flint and pebbles washed out of the chalk raised from
the water-source, and supposed not to have been broken
in punching, but to have laid among the water in their
present condition. In cutting a solid piece of chalk,
which had been brought up in the auger, a morsel of flint,
exactly like these specimens, was observed, with every
appearance of not having been forced into its place in the
chalk by violence.

The principal impurity discovered in this water by the action of

reagents is common salt, of which it contains about four grains
and a half in the pint. When evaporated to dryness, the residue

74 Overflowing Well at Chiswick.

contains a sufficient quantity of carbonate of soda to render it very
manifestly alcaline ; this is also the case with the waters of the
other deep wells in and about London.

J. L.

Art. IX, On the Taylorian Theorem.

[To the Editor.]

Trinity College, Dublin,
October 11, 1823.
Sir,

I lately communicated to you a demonstration of the Taylorian
Theorem given to me at lecture in this University by Mr. Edward
Wilmot, a gentleman-commoner, and under-graduate of this col-
lege. The same gentleman has since given me an extension of
this to functions of several variables, which I now enclose. The
simplicity of the proof, and the elementary nature of its principles,
must render it very valuable to the student. You will observe
that it is independent of the Theorem of Maclaurin, and gives it as
a corollary. It is also free from the functional reasoning so ob-
jectionable in other proofs of this theorem.

I am, Sir, Sc. Sc.,
Dionysius LARDNER.

Let u = F (2,2',2",....+), , 2,0", §c., being independent
variables,
Let =F (r+ Aaa’ + Ax, a" + AB", ....0-)
And let this be supposed to be expanded according to the di
mensions of x + A a, Sc.
w= A(x + Ax) + A’(2’ + Ax’) + A’ (a" + Aa")....-
+ A, (a+ Ax)? + Ay (u’+ Ac’) + A," ike ey alee
+ B’ («+ Ax) (a’+ Ax’) + B (w+ Az) ("+ Ax’) + B
Ce ACE AE) i avetis's
+ A, (z+ day + Ay (2'+ Avy + A,” (2° + Ax’) ytite.

On the Taylorian Theorem. 75

Hence
u= Aa’ + A'e' + A”2' uw
Aya? + Asx og Ng pay. Ce
B" xa + Bax’ + Ba'a"
Ax + Aja? + A,r...
Foeernen 8)
This being successively differentiated for each of the variables, gives
dt ng + Bae + = Sits di
dx x
= Aw {A+2A,¢+B'r'+B'a"+3A,27 ..... }

+ Ax {A'+2A,’c'+B’e+Ba"43A,'x'2 .... 3
+ Ax’ {A"4+2A,"c"4+Ba'+Bia+3A,"2"2...4

§ d2u Ax? du =Ax® Pe dus Aa’? , a
dx? 1.2 oie | ose Hast
At fA, +t SAg ty» wir. giriaiiere
ee CR eae Bh ee ks t> F
TED RSE Se) Wee a a ar te

eee OREM AE Pete Dt ca teiny

feu) BEAL deus AT Aa ss Na) Ie Ae 7
dxda 1 dz dz” 1 dat dah Ns
= Ag. Ag {B’....... }
ee RB. Tae}
ee eae 1 Ree ae }

. . ° . . (E)
The sum of the series (D) and (2) may evidently be expressed

thus,
d?u f Ax ra Ax 12
eda da’ meh ms

76 On the Taylorian Theorem.

And hence if the series (A) be arranged by the dimensions of
the quantities, Aw, Aa’, Ax", ..... and the substitutions sug-
gested by the series (B), (C), (D), (E), Sc., being made, the re-
sult will be

du Ax d2u Az \2 d3u
eee (a2) ae
is i aoa a da 1.2.3
(s a a.’ Raeee
dx
In which the symbol S = signifies
dx
Ar Ax Aa’
dg age Ge

The meaning of the symbols we ( e222 )' §c., is suffi-
1.2 dx

ciently obvious.
Ne 8
dx dx

The series of Maclaurin may easily be inferred from it by sup-

This becomes identical with Taylor’s series when S

posing « = 0 and changing Az into a.

a

. 79

Arr. X. ASTRONOMICAL PHENOMENA arranged in Order of Suc-

cession, for the Months of April, May, and June, in the Year 1824.
(Continued from Page 297.)

APRIL.
Plaviet’s or ie #| Sidereal Planet’s or Planet’s or = 2| Sidereul Planet’s or

-. Star’s re Star’s x Star’s a5 > Star’s

T2| Name, &c. |&“| Time. Declination. = Name, &c a! Time. » Declination,

ie A e Se

{a j=? a =°

! H. M.D. M. H.M. OD. M.

#1} Sun... .. 043 4 38N Im.Jupiter 12 28or 1132’ mr.

| Mars... 12°11. 2’ 8N Im. * 7. .| 7| 12 460r11'49 mr.

\ Juno... 14418 2198S ¥’s R.A. 615’ Decl. 23° 32’ N (2’S)
Venus .. 2255 8145 Im. * 8. .| 7| 12 5lorl]"54’ mr.

} | Mercury . 013 0 46S ¥’s R.A. 6"15’ Decl. 23° 25’ N. (1/S)

#2} Sun ... 047 5 IN Im.¥9..| | 12 58o0rl21’ wr.

4 Im. ¥. . 17.81 10 47or10"3’ mr. *s R.A. 6"15’ Decl. 23°48’ N. (cont.)
*’s R.A. 3614’ Decl. 21° 25’ N. (0’) Em. Jup,. 12 220r12"25’ mr.
Em... . 11 330r10"49’ mr. (4’N.) Em. *7. 3 35o0rl12" 38’ mr.(4N)
Mars... 1210 2 16N Em. ¥ 8 ° 13 36 0r12"39’ mr. (5’N)
Juno... 14 17 age Juno ..° 1415 1498S
Venus .. 23 0 =%747S Venus .. 23 14 6387S

| Mercury . 020 0 5N Mercury . 040 240N
3} Sun.... 0 50 ST OEN 6} Sun... 1 1 633N
‘| Im. ¥. . |7.8;) 9 400r 8! 51’ ut. Moon... 7.3, 22 "GN
x's R.A. 4" 9’ Decl. 23° 36’ N. (4’S.) Mars... 12 4 242N
Em. ... 10 3lor 9542 mr. (0') Juno... 1415, 1418
Mars... 12 8 2 23N Venus .. 23 18 6°0°S
Juno... 1417 2 48 Mercury . 048 3&8 34N
Venus .. 23 4 7208S TieSEmi aed. 1 5 655N

} | Mercury . 026 0 56N Moon. . * 8 4 18 30N

44) Sunn... 054 547N 20 Canc. .| 6] 813 18 53N
Em. 2 Sat.| | 11 480rl0 55’ mr. (98) CT ae 5-6] 8 22 18 41N
Mars... 12 7 229N VII. 112.) 8} 8 28 19 53N
Juno... 1416 1568S Im. *1..] 71 8 400r 7 36 mr.
Venus .. 23.9... 6538S ¥’s R.A. 8 4’ Decl. 18° 12! N. (16/S.)

Py. 033 147N Em. * 1 | 9 13o0r 8" 9’ mr.(11'S.)

BsiSon... . 058 610N Im. *¥2.. 9 200r 816’ Mr.
Moon. . | 6 0 24 11N *’s R.A. 8" 6’ Decl, 18° 5’ N. (14’S.)
Im. ¥* 1. {1.8} 7 520r 6556’mrT. Em. 3 Sat. 9 38or 8'34’mr.(+100)
%s R.A. 6h 3’ Decl. 24° 2’ N. (7S.) Em. * 2 . 10 Tor 816 mr. (5'S.)
Em.*¥1 . 8 44or 7" 48’ mr. (1S) Em. 1] Sat, 11 150r10"11’m7.(+100)
Im. * 2. | 7| 8 47or 751’ mr. Mars... . 12 3 2 48N
%’s R.A. 6" 6 Decl. 24° 1’ N.(2’S.) Juno... 14 14 1 348
Im. * 3. .| 7| 9 180r 8) 22’ wr. Venus .. 28 23 «5 33S
%’s R.A. 6" 6 Decl. 23° 47’ N. (12’S.) Mercury . 0-55. 4. 27
Em.*2 . 9 450r 8 49’ mr.(5N)]] 8} Sun... Te oO 7 Te
Em. *3 .- 10 lor 9" 5’ mr. (7S) Moon.. . 9 3 18 38N
Im.*4 .| 8].10 Sor 9° 7 mr. IX. 55. /7.8) 912 13 51N
%’s R.A. 6" 8 Decl. 23° 40’ N. (14S.) Im. 4 Sat. 9 13o0r 8" 4’ mr.(+100)

| Im. %5. 7.8] 10 130r 9" 17 mr. (9S.) IX. 84 .-+/7.8} 917 15 4N

‘| Em. *4 . 10 360r 9'40’mr.(11’S.) IX. 120. .|7-8} 9 25 13 26N
Em.*5. 10 520r 9"56’ mr. (9’S.) Mars... 12 1 2 54N
Im.*.6 .| 8] 11 20 orl0 24’ mr. Em. 4 Sat. 12 6o0rl0"58'mr.(+101)
#s R.A. 6! 11’ Decl. 23° 50° N. (5’N.) Juno... 1413 1278
Em. * 6 12 8orll!?mr.(11/N) Venus .. 2397, 5 "5S
Mars aia | 12,5. 2 86N Mercury . 13 52N

Days.
Magnitude
of Stars.

9} Sun... . ]
IX. 202, .| Sie .9
m Leonis .|4-5| 9
Moon... 9:

43 Leonis| 6} 10
Mars ... 12
JUNO ye wie 14
Venus .. 23
Mercury . 1
SUN, sss 1
Mercury . 1

Moon... 10
65 Leonis.|5.6) 10
69 Leonis.|5.6) 11
he: hae 11
JUNG, > 14
Im. ¥. . 6.7] 16
xs R.A. 115 6’
Em.x* .. 17

Venus .. 23
SUN, ay. we ]
XI. 148. ./6-7} 11
MLwbie of Shel)
Moon... 11
GE 2 Oy | a
Mars... 11
JUDGEe ss 14
Venus ,. 23
SODy. wo 4 1
Mars... 11

Moon... 12

Em. *.. 9
Mars... « 11
75. Virg. | 6| 13
XII. 139 | 8} 13
83 Virg. | 6) 13

Moon... 13
Juno... 14
Venus . . 23
Sun aa «4 ]
Mercury . 14

Em. 3 Sat. 10

H.

55 Leonis | 6| 10 «

49 Virg. |5.6] 12
52Virg.. | 8} 13
XIU. 25.7.8) 13
JUNO. + «= 0 14
Venus .. 23
SOD a5 0 « 1
Mercury . 1
Im. %.. 6.7] 8

Planet’s or é! Sidereal
Star’s /
Name, &c. Time.

12

833or 15°16’ MT.
Decl. 0° 17’ S. (14’ S.)
17 orl5" 59’ MT. (38.)

32

39 or 7 11’ mt.
x’s R.A. 13 31’ Decl. 15° 33'S. (16'S.)
190r MSY mr. (8'S.)

55
93
28
35
39

9
50
a

50 or 918’ 7r.(+100.).

no Ode oR ROD

_ _
woonovweo

©

9

Planet’s or
Star’s
Declination.

M
40N
54N

128

10S
24N

n
ZDP

4N

$ 20N
278
838
178
188
508
478
30N
59N

=

SO OWE EO SD RY 60 2 =) COTE

Astronomical Phenomena.

APRIL.

a —

Planet’s or |= “] Sidereal Planet’s or

" Star’s 28 . Star’s

= Name, &e. | Time. Declination.

Z =

H. M. D. M.

Mars... 1154 8 24N
Juno... 14 9 0 48S
XIV. 116.| 7} 14 25 19 49S
Moon. 14 36 20 428
10 Libre .| 7] 14 42 17 87S
Im. ¥. . .| 7] 14 45 0r13" 12’ mt.
x’s R.A. 14 37’ Decl. 20° 35'S. (cont.
XIV. ay 4 14 47 20 36S
Im. ¥ 7.8| 19 590rl8" 25’ mT.
x’s R.A. 14.47’ Decl. 21° 26'N. (5N.)
Em. *. 20 48o0r19"14’mr.(10'N
Venus .. 93 54 2198

15} Sun.... 134, “9 5IN
Mercury .« 147 10 54N
Mars... 1153 $8 30N
RU wis 14 8 0368S
Im. ¥ . 6| 14 16 0rl2" 40’ wr.
xs R.A. 15" 34’ Decl. 23° 50’ N. (2’S.)
Em. * . . 15 24 0r13'47 mr.(6N.
42 Libre .|5.6} 15 30 23 148
Moon... 15 35 23 50S
XV. 192 || 6] 15 43 23 27S
XV. 213 7.8} 15 48 23 18
Im. ¥.. -| 6| 20 4o0r18" 27 mr.
¥’s R.A. 15" 43’ Decl. 24° 0’ N. (cont.
Venus .. 23 59 +1518

TEL Sian ots ile 138 10 129N
Mercury 155 11 50N
Mars . LY 52 38 31N
Im. ¥. . .!7.8] 13 49or12" 9 (mr)
¥'s R.A. 16" 29’ Decl. 25° 42’S. (15'S
Em.*..- 14 2orl2'22’mr.(14'S,,
Juno.. 14 7 0298 ;
Venus .. 0. 3). 4-335 ¢

17] Sun... ‘] | 142. 10 88N ;
Mercury - 2.8, 12 48N
Mars... 11 51 8 35N
JUDD, ous 14° 6. 022958
Venus... (Oa Pe

1S) Sat cece 145 10 54N
Mercury . 2 31, 18 37-N
Mars. «.. 4 1150 $3 38N
Im. ¥ ... .|7.8}.13 21orl1533’ ur.
¥s R.A..18" 20’ Decl. 25° 0’ N. (5S.)
Juno... 14.5.0 Tas
Em. * .. 14 18 o0rl2"30° mr. (5S.
Venus .. 012 0268S

19} Sun. 149 11 15N
Mercury . 219 14 40N
Mars... 1150 340N
Juno... 145) OO oe :
Im. % 1. .]7.8) 14 190r124 27’ mr.

ror

~——

2
>

21)

22

23

24

Astronomical Phenomena.

APRIL.
=
Planet’s or |5 | Sidereal Planet’s or
itar’s as Star's .
Name, &e. x! Time, Declination. =a
Be 4

M. D..M.
#’s R.A. 195 14! Decl. 22° 54'S. (4S.)
Im. * 2. .]7.8] 14 51orl2h59’ wr.
#s R.A. 198 15! Decl. 22° 47’ S. (1'N.)

Em.¥1 . 15 140r13" 99’ mr.(8’S.)
Em. * 2 15 57orl4" 5’ mr. 3’S.)
Venus .. 017 O 2N 26
Sun. ... 153 11 36N

Mereury . 227 15 19N
Mars... 1149 3 43N
Juno... 14\i4' 0.28

‘Im. *¥1. .| 8] 14 530r12" 57 mr. 27

%’s R.A. 20" 5’ Decl. 19° 44’ S.(5’N.)
Em.*1. 15 540r13"58' mr. (2’S.)
Im.¥ 2. .| 81.16 Oorl4' 4’ mr.

#’s R.A. 20" 6! ne 19° 26'S. (cont.)

Venus .. 0 21 0 30N 28
Sun... . 157 11 56N

Mercury . 235 16 8N

Mark ii. 4 1148 8 45N

Junge 14 3 0 4N

Venus .. 026 0 59N 29
Suns: : 2 0 12 16N

Mercury . 243 1657N

Mary 2/.. 4 1147 347N
Juno... 14 2 011N

Venus .. 030 127N 30
Sune 2. 4 2 4 12 36N

Mercury . 251 17 41N

Em. 1 Sat. 10 38or 8"3)’mr. ceibod
“Mars... 1147 38 48N
Juno... 14 1 O17N

Venus .. 034 1 56N

Buns ar. 5 2. 8) 12 SEN

Mereury . 259 18 24N

Mars. . 1146 3 49N

JUNG. §) » 14 1 0 23N

Venus .. 039 2 24N

79

Planet’s or = | Sidereal Planet’s or
Star’s aie Star’s
Name, &e, Ee Time. Declination.
= 9
H. M. D. M.

Sunde. 2 212 13 16N
Mercury . Se): 19. ween i
Mars... 1145 3 50N '
Juno . 13 0 O 29N
Venus . 043 2 58N
Sune %."% 215 13 35N
Mereury . 3:14 19 44N
Mars .. J 1145 $3 51N i
Juno... 1359 O 85N }
Venus .. 047 +3 Q1N i
Sun... 219 13 54N |
Mercury . 3 21 20 20N }
Mars... 1144 $8 51N
Juno... 13 58 0 41N .
Venus .. 052 3 50N
Sun. . 223. 14 18N
Mercury . 3.28 20 56N
Mars... 1144 351N {
Juno... YSP58! 10 “4a |
Venus .. 056 418N
Sun... 227 14 32N
Mercury 3 386 21 27N
Mars 43.1 1144 $51N
Junot, 2h. 13 57 0 53N P|
Venus 11 4 46N
Suny gat 231 14 51N
Mercury . 3.43 21 57N
Im. ¥1. .J7.8} 9 59o0r 7) 24’ MT.

x’s R.A. 3 49" Decl. 23° 7’ N, (cont.)
Im. * 2. .|T. 8 10 220r 7 47’ ur.
¥’s R.A. 8h 50! Decl. 22° 42’ N. (3/8.

Em. * 2 11 8or 8" 33’ mr. a)
Mars... 11/43) 3 50N
Em. I Sat, 13 lor 10"26’mr.(+100)
Juno... 13 56 0 58N
Venus ., Tf “Sy 4). eee

Planet’s or
Star’s
Name, &e.

Venus ..

Sun..

Mercury .«

Moon. .

| Sidereal

Time.

Magnitude
of Stars.

H. M.
1 32
2 57
4 24
10 36

80 Astronomical Phenomena.
MAY.
Planet’s or = #| Sidereal Planet’s or
5 Star’s ras , Star's. :
> Name, &c. oe Time. Declination. 2
4 Be A
H. M. D. M.
1} Sun. . 234 15-9N
Mereury . 349 22 23N 7
Mars... 1143 3 49N
Im. *.. | 6] 13. 3 orl0% 24 wr.
#’s R.A. 4" 57 Decl. 24° I'N, (1'S.)

Im*...

Planet’s or
Star’s
Declination,

D. M.
8 ON
16 53N
24 11N -
3 35N

6| 10 37or . 34 Mr.

Em. 13 47 or]1" 8 mr. (0’.) *’s R.A. 10" 36 Decl. 3° 15’ N. (7S. J
Venus .. 110 5 43N X.172 . | 8] 10 42 4 31N

2} Sunk ii. % 288 15 27N 58 Leonis] 5] 10 51 4 34N
Mercury . 355 22 45N XK. 2B" 1055 4 35N
Mars . 1145 3 48N Mars 11°42; 8 83TNiws
Im. ¥ 1. .| 8] 12 8or 95 95’ wr. Em. * 11 49or 846’mr ae
%’s R.A, 5 55’ Decl. 23° 39’ N. (12’S.) Venus 137 8 28N
Im. * 2. || I 12 23or 9" 40’ mr. 8} Sun . $ 1 17 9N
%’s R.A. 5h 56 Decl. 23° 39’ N. (11’S.) Mercury . 4 8 24 19N
Em. ¥1 , 12 42 or 9°59’ mr.(8S.) 87 Leonis}4.5] 1121 2.28
Em.*2 , 13° 2orl0" 19’ wr. (68.) Moon... 1128 2 36S
Venus .. 114 610N Mars... 11/42. 3 34N

3} Sun... , 242 15 44N XI. 179. .| 8} 1145 2 48S
Mercury . 4 1 23.6N XI. 213. J T)11'52) 0 478
Mars... 1143 3 46N Venus 142 8 55N
Im. *¥.. .| 7] 13 340r10"47 wr. 9] Sun . 30 Sy 1h) 250)
*’s R.A. 6! 0’ Decl. 21° 33’ N. (9'S.) Mercury . 433 24 27N
Em. ... 14 2lorll" 3¥ mr.(1’S.) Mars 11%42 38 30
Venus . . 119 6 S8N 14 Virg. |6.7] 12.10 7 56S

4; Sun. 246 16.2N Moon... 1221 8233S
Mercury . 4 7 23 28N 22 Virg. |5.61 12 25 8 29S
Im. * 1. .|7.8} 10 350r 74 45! wr. 31 d/l... 4.6]'12433 . 8 «2.8
x’s R.A. 7 51’ Decl. 18° 49’ N. (cont.) Im. *. . .| 7! 16 48 0113 37’ mr.
Im. ¥2. || 7| 10 350r 7 45° Mr. *’s R.A, 12) rita 2° (1VS.)
¥’s R.A. 7 59" Decl. 18° 43 N.(15'S.) Em. 49 or 14°37 Mr(1/N.
Em. * 2 J1 190r 8 29’ mr.(7’/N) Venus .. A 46 9 2I1N
Mars .. 1142 3 44N 10) ‘Sune sit 34 9) l%:4la
Im.* 3. .| 6] 15 Torl2h16' mr. Mercury . 4 37 24 35M
*’s R.A. 84 2’ Decl. 18° 10’ N. (9'N.) Mars... 1143 3 27N
Em. x3. 15 tle hn tt XIII. 19 7-8 13 4 12 32S
Venus 23 7. SN Moon 1315 14108

a Sn oY 250 16 19N 75 Virg. .| 6] 13 23 14 27S
Mercury . 413 23 42N XII. 177 |7.8, 13 35 18 20S
Moon... 845 14 59N Venus .. 151 9 48S
Mars®.” >. 11 42 3 42N 11} Sun. 313 17 56N
Venus’. | 28 Rasa, Mercury . 441 24 37N

6} Sun. . 250 16 19N Mars. . 1143 3 23N
Mercury . 413 23 42N XIV.22 | 6114 6 17 23S
Moon... 941 9 34N Moon.. - 1411 18 56S
Im. *¥1. | 8] 11 35or 836’ mr. XIV.116.) 7; 14 25 19 40S
xs R.A. 9h 45’ Decl. 8° 54’N (19'S ) 10 Libre | 7| 14 42 17.378
Mars. . 11 42 3 39N Im.*¥ 1. J7.8 16 28 o0r13"9 mr.
Em. ¥ 1 12 41or 9542’mr.(3'N.) ¥s R.A. 14h 16’ Decl. 19° 10’ S.(12’/N.
Im. ¥2.. 12 57or 9958’ Mr. Im. * 2. .| 7] 16 300r13" 11 wr.

*s R.A. 9" 47’ Decl. 8° 30’ N. (16’S.)
Em. 2 Sat. + 35 or10"36’m1(+100.)
Em. * 2 13 39 or]0"40’mr.(15’S.)

¥s R.A. 14" 16’ Decl. 199(10’S, )(12°N.
Em. *1. 16 520r13" 33'mr.(16'N
Em.*2 . 16 520r1333'MT.(15'N. :,

Astronomical Phenomena.

14

MAY.
Planet’s or |S #| Sidereal Planet’s or
Star’s ee s = Star’s z
Name, &c. ua Time Declination. 2.
ES a
H. M.D. M.
Venus .. 156 1015N
Sun.... 317 18 12N
Mercury . 445 24 39N
Mars... 1143 3.19N
XIV. 262 | 7) 14 56 22 38S
XIV. 282.) 6} 15 0 2318S
Moon... 15 9 22 34S
XV. 65.. 15 16 2045S
Venus .. 2 0 10 41N
Sun.... 321 18 27N
Mercury - 4 48 be 41N 17
Mars... 1143 3 15N
Im. * 1. |7.8) 14 16 0rl0" 49’ mr.
x’s R.A: 16" 6) Decl. 25° 0’ S. (15/S.)
Im. * 2. .| 7| 14 20 orl0"53' mr,
%'s R.A. 16! 4’ Decl. 25° 1’ N. (cont.)
Em. ¥ 1. . 14 37o0rl11"10'mvr.(13’S.)
Moon... 16.7 2453S 18
oScorpii .|5.6) 16 10 23 44S
Poet Dy le 15° 23° "2S
SoC. s al 6) £6.20 24.425
Im. *.. 1 4117 29or14! nur. 19
%'s R.A. 16" 10’ Decl. 25° 10’ S. (10'S.)
Em.* .. 4 250114558’ mr.(7S.)
Venus . 5 11 8N
Sun’... ee 18 41N
Mercury . 451 24 38N
Mars~... 11 44 3 10N
XVL.248 | 6] 1649 2449S 20
28 Oph. | 7| 16 53 25 26S
Moon. 17 6 25 48S
6 Oph. . 3.4) 17 11 24 49S
Venus 210 11 33N 21
Sun... . 329 18 55N
Mercury : 454 24 34N
‘Mars. . 1144 3 5N
Im. * 1. .J 7! 14 180r 10°44’ mr.

#’s RA. 17 58 Decl. 25° 29 S. (13'S.)
Im.*¥2..| 7| 14 24 0r10! 50’ MT.
¥’s R.A. 17 58 Decl. 25° 29’ S. (19'S.)| 22

Im. *3 . 6 14 240110" 50'mr.
Em.*1.. 14 560r11"21’m7v.519’s.)
%’s R.A. 174 58" Decl. 25° 29'S. (12'8.)
Em, *2 & 3 15 1lorl1'26’mr.(19'S.)},.23
63 Oph. 6.7] 17 44 24 51S
4Sagit.. | 5| 17 49 23 478
XVII. 342] 7] 17 54 24 248
Moon. . 18 3 25108 24
Venus .. 214 11 58N
Son. ,. 31387 19 “ON
Mercury . 457 24 31N
Mars :.. 1144. 8 ON

vies
Vou. XVIT. G

2
Planet’s or | 4] Sidereal Planet’s or
Star’s 2s tar’s.
Name, ke. | #“| Time, Declination.
SS
Lae D. M.
Im. * 1. .[8.9} 13 S4orl0" 16 MT.

¥s R.A. 18" 51! Decl. 23° 28'S. (13'N. )
bm. * 1 . 14 29 orl0*51mr.(12‘N.}
Im. * 2. 17 51orl4" 12’ wr,

x's R.A. 18" 58! Decl. 23° 27'S. (1/S.)
Im.x%3. J | 18 250r14"46 mr

x's R.A. 18" 59! Decl. 23° 28" 8. (4’S.)

Em. * 2 19 9orl5'30! mr. (1’S.)
Em,* 3 . 19 330r15" 54’ wr. (9S.)
Venus .. DAN |.19-93iNi
Sun..-. 3 37 19 23N
Mercury . 459 24 22N

Mars .. 1145 2.55N

Im. *¥.. .| 8] 18 57orl5" 14’ Mr.

%’s R.A. 19" 50’ Decl. 20° 20! S. (4’S.)

Em. *.. 19 530r16 10mr.(9'S.)
Venus . 224 12 48N

Sun: elie 3 41 19 36N.
Mars... . 5 1). 24 14N
Mercury . 1145 2 49N
Venus .. 228 13 13N
Sun... 3.45 19 49N
Mercury . 5 2 24 5N
Mars... 1146 2 44N

Im. ¥. 17 4o0rl3413’mr.

x’s R.A. 21h 93' Decl. 13° ’S.) 1'N.)

Em.*¥ ..[ | [| 18 Torl4"16’mr.(10'S.)
Venus .. 2 33 13) -38

Sum. ... 349 20° 2N
Mercury . 5 2 23 52N

Mars . 1146 2 38N

Venus 238 14 1N

Sun... ; 3 53 20 14N
Mercury . 5 3 23 40

Mars, . 11 47. 2 31N

Im. *¥. . 18.9] 17 300r13%31'mr.

*’s R.A. 22" 51’ Decl, 3° 23'S. (1'N.)
Em... 18 28o0rl4%29’mr.(10'S.)
Venus 243 14 24N
Sun... 38 57 20 26N
Mercury .« 5 3 23 27N
Mars... 11 47 .2-25N
Venus ., 247 14 47N
Sun. 4 1 20 38N
Mercury . 5 3 23 11N
Mars... 1148 ¢%18N
Venus 2 52 15 11N

DGD, f5'75,74 4 5. 20:49N
Mercury . 5 2, 22 54N
Mars . 1149 212N

Im. %.. Ins 19 240r15"13' wr.

#'s R.A. 1" 9! Decl. 12° 19".N, (14'N.)

82. Astronomical Phenomena.

n

Planet’s or
Star’s
Name, &e.

‘| Sidereal Planet’s or Planet’s or
Star’s a Star’s
Time. Declination. 2 | Name, &e.

Magnitude
of Stars
gnitude
of Stars:

Ma,

H. M. D. M. |
Em. * .. 19 33o0r15"29’m7.(13'N.) Mercury .
Venus .. 257 15 .34N Mars ...
Sun.... #19 )21, ON Venus. ..
Mercury . 5 2 22 38N SON ufphous
Mars... 1150 2 5N Mercury .-
Im. %.. .| 7| 18 590r14"45’ mr. Mars...
*’s R.A. 250’ Decl. 16° 24’ N. (8'N.) Venus .,
Em.%... 19 500115" 36’ mr. (2’N.)) 30] Sun. . .
Venus .. 3 2 15 57N Mercury .
Sun;.Gdck. 21 10N Mars... 27N
Mercury . 22.19N Im. %.. ./6.7| 14 370r10" 3’ mr.
Mars... 157N %'s R.A. 6" 41' Decl. 22° 0’ N. (6/S.)
Venus .. 16 18N Em. *¥.. 15 20 orl0"46'mr.(4'N.)
DUD ey. Dol ® 21 20N Venus .. 327 1740N
Mercury . 22 ON 31} Sun. ... 33 21 57N
Mars... 1 50N Mercury . 53 20 42N
Im. 3 Sat. 13 40or9"19’m7r.(4+100) Mars... 55 118N

421 21 30N Venus .. 32 18 ON

JUNE,
H. M. D. M. H. M. D. Ms
1} Sun... 487 22 5N Mercury . 442 19 5N
Mercury . 451 20 21N Ot SUD ve bens 454 22 35N .
Georgian . 9 e6 (2s Ts Moon... 12 5 6558
Venus .. $3 37 18 21N Im. #1. .|7.8| 14 390r 9" 49’ mr.
2} Sun... 441 22 14N %’s R.A. 12" 8’ Decl. 7° 48’ S. (15'S.)
Mercury . 449 20 1N Im. ¥2. .| 8| 15 180r10"16' mr.
Im. x. . .| 7] 15 560r]11" 11)’ ur. *’s R.A. 12" 9’ Decl. 7° 55S. (16S.)
xs R.A. 94 36’ Decl. 9° 41’ N. (5'N.) Em. ¥ 1] . 15 150rl0" 18’ m7.(8’S.)
Bim) oe ia « 16 350r11"50’mr.(14’°N))|” | Im. ¥ 3. 15 3lorl0"34’ arr.
Georgian . 19°. G6) 23° US x's R.A. 12" 10’ Decl. 7° 56S. (14’S.)
Venus .. $ 42 18 38N Em. *3 . 15 490rl0'52’ mr. (5'S.)
3} Subp. j<: 445 22 21N Em. * 2. 15 5lorl0"54’ m7. 10'S. |
| Moon... 1018 5 15N Georgian . 19 15° 2%, (25
Im... .[6.7] 15 240r10"35’ wr. Venus .. 2 57 19 :3uUN
x's R.A. 108 27’ Decl. 4° 27’ S. (cont.) Mercury. . 440 18 50N
Georgian . 1.26) 24°08 6) Sun. ,..- 457 22 41N
Venus - . 3.47 18 56N Moon... 12 57 12 328
Mercury . 444 19 292N Georgian . 19 5 23 28
4] Sun.... 449 22 28N Venus .. 4 2 19 48N
Moon... a1 71); @ 538 Mereury . 439 18 35N
Im. ¥ 1. .{7.8' 15 40 0rl0 47 mr. 7] Sun... . 572722 40
%’s R.A. 11" 20’ Decl. 2° 1’ S. (8'N.) Moon... 13 51 17 288
Im. ¥ 2. .|4.5| 16 llorll§18’ mr. XII. 317 | 6} 14 1 15 28S
%’s R.A. 11" 21’ Decl. 2° 2’S. (1’S.) XIV. 22 | 6} 14 6 17 23S
Em.¥1 . 16 40 orll'47/mr.(7S.) XIV. 38 J7.8) 14 10 17 4258
Em. *2 . 17 6orl2"13M7.(19S.) Georgian . 19%: 5; 2B 28
Georgian . 19,5 28 28 Venus . . 4 7 20 6N
Venus .. 3 52 19 13N Mercury . 4 37 18 20N

>

P

cS

| ¥’s R.A. 16!

Astronomical Phenomena.

#’s R.A. 15! 59’ Decl. 24° 31'S. (4’S.)

Em. * 4 °
Venus’ ..:
Mercury .
Sun....
Im. *1..

*’s R.A. 16" 36’ Decl 25° 19’S.

Em.* 1.
Im.¥2..

20 290rl15"15’mr. (3’N.)

4°17. 20. 35.N
433 17 58N
514 23.3N

6] 12 240r 748’ mr.

(2N.)
13 23 or 87’ mr. (6N.)
15 Sor 95)'mr.

%’s R.A. 16" 41’ Decl. 25° 18'S. (7'N.)

Im. *3. .|

| 15 21orl0°4’ mr.

#’s R.A. 16" 41’ Decl. 25° 17'S. (8/N.)

Em.*2 .
Em. * 3
Im.% 4. .

25 Scorpiil 6
18 Oph. | 6
Moon...
26 Oph. || 6
Em. *4 .
Georgian .

16 17o0r11"0’ mr.(11’N.)

16 17orl11'0’ mT.(11/N.)
16 320r11"15/ mr,

44’ Decl. 25° 32’ S. (3’S.)

16 36 25 12S
16 39 24198
16 43 25 33S
16 49 24 43S
17 300rl2 137. (1’S.)
19 4 28 88

G2

15

Im. #1. .}7.8] 14

83

JUNE.
Planet’s or ¢ 2] Sidereal” Planet’s or Planet’s or z | Sidereal Planet’s or
's aS Star’s Star’s ie Star’s
Name, &e. me Time. Declination. S Name, &e uP Time. Declination.
ae A ere
H.™M, OD. M. H.M. D. M.
Sun.... 5 6 22 53N Venus 4 22 20 49N
Im. *#1.. 14 13or 9" 5’ mT. Mercury 4 32 17 47N
¥’s R.A. 14" 47" Decl. 219 26'S. (2S.) {|11] Sun. . 5 18 23 7N
XIV.171.) 7) 14 37 20 35S Moon... 17 40 25 318
Moon... 14 47 21 248 63 Oph. .|6.7} 17 44 24 51S
XV.19../6.7/ 15 6 2144S 4 Sagit.. 15] 17 49 23 47S
Im. ¥ 2. .|7-8] 15 Sor 9459’ ur. XVII. 342] 7] 17 54 24 9458
#’s R.A. 14" 49’ Decl. 219 41’ S. (10’S.)]]_ | Georgian . 19° 4 23-38
XV.65..) 8) 15 16 2045S Venus .. Al2T) 21°.38N
Em. * 1 15 25o0r10" 16’ mr. (8'8.) Mercury . 431 17 41N
Em.*2 . 16 I4orll*5’mr.(@S.) |]12 Sun.... 5 22 23 11N
Georgian . Tg 57 2b 9 Im. *. . .| 8] 15 390r10" 14’ mr.
‘Venus .. 412 20 20N *’sR.A. 18" 32’ Decl. 24° 6’ S. (15’N.)
Mercury . 435 18 9N Em.¥ .. 16 Sorl0'43’mr.C14'N.)
Sun.... 5 10 22 58N XVIII.129] 6] 18 28 23 39S
Im. ¥1. ‘ 6| 14 29or 9°16 mr. XVIII.141] 6] 18 31 23 598
*’s R.A. 15" 43’ Decl. 24° 0’ S. (6'N.) Moon... 18 37 24 9§
Im. *2..| | 14 45o0r 95 39’. vSagit.. | 5] 18 44 99 57S
x's R.A. 15" 44’ Decl. 24° 9’ S. (5’N.) Georgian . 19 4 23 38
Em.*¥ 1. 15 23o0r10"10’7.(12'N.) Mercury - 430 17 36N
42 Libre .|5.6] 15 30 23 14S Venus .. 432 21 17N
XV.149 .I7.8) 15 33 24 51S 13) Sunn 0. 527 23 14N
Moon. . 1545 24 9S Georgian . 19 4 28 4S
Em.*2 . 15 47o0rl10"34’mT.(11’N.) XIX.138 | 6} 19 20 2140S
KV 2225 4°3|'15"50 227) 7's. XIX. 166., 7] 19 25 21 9S
Im #3. .'6.71 17 4orll1"51'mr. Moon... 19 30 21 87S
%’s R.A. 15" 48’ Decl. 24° 20'S. (1’S.) 56 Sagit. .| 6] 19 36 20 10S
Em. #3 . 18 150r13"2’mr.(3'N.) Mercury . 429 17 30N
Georgian . 19%). 23 h3'S Venusy. * 4 37 21 32N
Im.*4. | 7] 19 270r1414’mr, 14, Sun.... 5 31 23 18N

52o0r 920’ wr.

¥’s R.A. 20" 11’ Decl.18° 52'S. (9'S.)

15
15

Em. ¥* 1
Im. ¥ 2.

| |

48 orl10"16 mr.(2’N.)
53orl0hel’ ur.

*’s R.A. 20 13’ Decl. 18° 54’ S. (0’)

59 orl 1) 26’ m'r.(7'S.)
0 orl3h27 wr.

*’s R.A. 20 17’ Decl. 18° 46’ S. (cont.)

Em. * 2 | 16
Im. ¥8. | 5] 19
Georgian | 19
Im.*¥ 4. .} 5] 19

4 938-4§
39 0r14" 6 wr.

%’s R.A. 20" 19’ Decl. 18° 23’ S. (3’N.)

Im. ¥5. .|7.8| 19

43 orl4! 10’ mr.

*’s R.A. 20" 19’ Decl. 18° 27’ S. (1’S.)

XX. 45. | 8] 20
Moon... 20
XX. 194 | 7} 20
XX. 240. 20
Km. * 5 ./6.7) 20
Em.*4 . 20
Mereury . 4
Venus .. 4
MUN. os 5

6 1649S

31 1645S
53 0r15"20'mr.( 11'S.)
56 o0r15" 23’ wr. (9'S.)
30 17 30N
42 21 48N
85 23 20N

84

Astronomical Phenomena.

a
a
=
=

20

21

Planct’s or z 2) Sidereal Planet’s or

Star’s 2g Star’s 5
. Name, &e. =? Time. Declination. 2

hy a
H. M. D. M.

Georgian . 19 4 23 48 22
Im. * 7. .| 7] 19 5lorl4'14’ wr.
#s R.A. 21" 8’ Decl. 14° 0’ S. (19’N.)
Em. * . | 21 lorl5" 24’ wr. (0’)
Mercury . 431 17 30N 23
Venus . 447 2154N
Sune tre 5 39 23 22N

Im. ¥ 1. |7.8] 16 550rl1514’ wr.
*’s R.A. 215 48’ Decl. 10° 24'S. (1VS.),

Em. ¥ 1 17 14or11"33 mr.(15’S.)
Georgian . 1953) 23.458

Im. * 2. |7.8, 20 440r15" 3’ wr. 24
#’s R.A. 21" 54’ Decl. 9° 21’S. (13’N.)
Em. *2 . 21 48orl6" 6’ mr. (1’N.)
Mercury . 4 31 17 30N

Venus .. 452 22 5N 25
Son. : 5°43 23 24N

Georgian . 19% 53)923 HS

Mercury . 4.32 17 36N

Venus .: 4:57). 22. 15N 26
Sun. . 5 47 23 26N

Im. *- . .| 61°18 58o0r13" 9 wr.

xs R.A. 23! 18’ Decl. 0° .10’N. (7S.)
Georgian . 19:3 323 25S 27
Em.%... 19 55o0r14" 6 mr. (0’.)
Mercury . 432 17 41N

Venus .. 5°12" )22 26N

Suny oe 4 5/52) 23 27N 28
Georgian . 19° 3) 23 .5S

Mercury .« 433 1747N

Venus .. 5 £189.220/3/

Sade sy : 5 56. 23 28N 29
Georgian . 19) (8...23 \6)S

Mercury . 435 17 57N

Venus .. 513 22 44N

Songs’ j-°< 6. 0 23 28N 30
Georgian . 19 vis fle: AS

Mercury . 438 18 8N

Venus .. 5019) 22 5)N

>
Sl ce
Planet’s or | 2 ¢| Sidereal Planet’s or
Star’s ote Star's.
Name, &c ep Time. Declination.
se
=

H.M. D. M. »
Sun... 6 4 23 28N
Georgian * 19. 3 23 6S
Mercury . 440 18 18N
Venus . . 5 24 22 58N
Sun. . 6 8 23 27N
Georgian . 19 3 23.78

Im* . . {6.7} 20 130r14"5! wer.
x's R.A. 3" 28’ Decl. 22° 5’ N. (19’S.)
Em. *.. - 20 47orl14" 38' mr. (7'S.)

Mercury . 443 18 32N
Venus .. 529 23 4N
Sun. 2. ¢ 612 23 26N
Georgian 19" 2) 2a" ins
Mercury - 445 18 46N
Venus 535 28 11N
Sun... 616 23 25N
Georgian . 19)°2¢ 23 .%S
Mercury . 448 19 ON
Venus . 5 40 23 18N
Sunisytné 6 21 23 23N
Georgian . 19 2 23 7S
Mercury - 452 19 16N
Venus . 5 45 23,21N
Sun... 6 25 23 20N
Georgian . 19 2 23 "8S
Mercury . 456 19 32N
Venus .. 5 51 23 25 N
Sun 629 23 18N
Georgian .« 19; 2. 23 8/8
Mercury .« 5 0 19 48N
Venus .- 5 56 23 28N
Sun.. 6 33 23 15N
Georgian . 19 1.93. 8S
Mercury .« 5 4 20 6N
Venus . 6 1 23 32N
SUiiet sae 6 37 23 11N
Georgian . 19 1 23 9S
Mercury . 5 9 20 24N
Venus... 6 7 23 36N

nti

a

85°

~ Arr. XI; -ASTRONOMICAL AND NAUTICAL
COLLECTIONS.
No. XVII.

i. Remarks on the Cavatocut of the Orbits of the Comets that have
been hitherto computed. By Dr. Orzers.

Tue Catalogue of the Orbits of Comets is founded on that which
Delambre has given in the third volume of his Astronomy, p. 409. Many
errors of the pen and of the press, in Delambre’s Catalogue, are corrected,
and those orbits are added which were-unknown to Delambre, or over-
looked by him, or which have been computed since the termination of -his
catalogue in 1813. Where several persons have computed the orbits of the
same comets, some of their results have been omitted, when they have been
manifestly incorrect, or derived only from a construction, or given merely
as examples of computation with inadequate observations, and by no means
intended to represent the correct orbits. Perhaps, however, too many in-
accurate computations have still been retained: but this has been done
with the intention of affording a conjecture how far the orbit may be more
or less remote from a parabola: and where the orbit has been found deci-
dedly elliptical, it is interesting to compare the difference of the parabolic
and the elliptic elements. And since so many orbits have now been com-
puted as elliptic or hyperbolic, a separate column has been added for the
eccentricities, Where this is left blank, the eccentricity is supposed to be
= 1, or the orbit to be parabolic. The eccentricity shows whether the
orbit is elliptic or hyperbolic, and thus renders the elements complete,
since the greater axis is easily found from the eccentricity and the least
distance. The logarithm of the mean motion is assigned in all cases, on
account of its utility in computing the true anomaly, even in the cases of
elliptic and hyperbolic orbits. For this logarithm of the mean motion we
have retained, on account of uniformity, the constant logarithm 9.9601283,
which has hitherto been commonly used, as the logarithm of the mean motion
of a comet, of which the least distance is=1. This value supposes properly
that the mass of the comet is equal to that of the earth: but if this mass,
which is indeed unknown, but which is certainly always very inconsiderable
became = 0, the logarithm should be 9.9601277:-so that if we required the
ee possible accuracy, it would be necessary to diminish the tabular

ogarithm of the mean motion by 6 in the 7th place of decimals.

With respect to the following remarks on the table of comets, I must
gratefully acknowledge the assistance that I have received from the excel-
lent notes which the Baron von Zach and the Baron von Lindenau have
respectively added to their tables. But for the sake of brevity, IT have
omitted many references which may be found in Pingré, or in other works
here quoted, and very extensively circulated.

r No. Year. J
1. 240. Chinese observations. A very uncertain orbit. Mon. Corr. X.

. 167.
2. 539. ae Chinese observations, without any latitudes. Mém.
prés. 4 l'Inst. I. p. 290. Mon, Corr. II. p. 415. XVI. p. 498.
_ 8. 565, Deduced from two Chinese observations only, upon the two
suppositions, that the curtate distance of the comet, at the
time of the first observation, was either = 1,2 or = 1.3, Al-

86 Astronomical and Nautical Collections.

No. Year.
though the elements have some resemblance with those of the
comets of 1683 and 1739, yet Burckhardt found that neither
of these two orbits would accord with the observations of 565.
Mon. Corr. X. p. 162,

4. 837. Chinese observations. Pingré Com. I. p. 340.

5. 989. Chinese observations, A very uncertain orbit. Mon. Corr. X.

p- 167.

6. 1066. Very uncertain orbit. Pingré I. p. 373.

7. 1097. From Chinese observations of the 6th, 16th, and 17th October.

Say. Etr. L p. 290. Mon. Corr. If. p. 417, XVI. p. 501.

8. 1231. Chinese observations. Pingré I. p. 401.

9. 1264. Phil. tr. XLVII. p. 281. Pingré I. p. 406. Mém. Par:
1760. p. 195. Struyck Vervolg Amst. 1753. p. 108, 109.
The identity with the comet of 1556 is uncertain from the
want of precision in both orbits.

10. 1299. Two European observations, and one Chinese: a third Euro-
pean record does not agree. Pingré I. p. 418.

11. 1301, Pingré has applied a correction to the European, and Burck-
hardt to the Chinese observations, which could not otherwise
be reconciled. Hence the diversity. Pingré I. p. 420, Mon.
Corr. X. p. 164.

12. 1337, Pingré I. p. 432. The orbit of Pingré is preferable to that of
Halley, since it represents both the European and the Chi-
nese observations tolerably well, while Halley's differs as far
as 208 fromthe latter.

13, 1351. Even the few elements, which Burckhardt has been able to
assign, are very uncertain. Pingré I. p. 487. Mon. Cor. IIL.
p- 415. Mem. Say. Etr. I. p. 290. There are only four
Chinese observations, of the 24th, 26th, 29th, and 30th No-
vember, without latitudes. On the whole we ean place no
manner of reliance on the orbits of the comets of 240, 539,
565, 989, 1066, 1097, 1231, 1299, 130], 1351, and 1352.

14. 1362. Mon. Corr. X. p. 166. Three Chinese observations. The
two orbits are derived from different. suppositions respecting
the latitudes.

15. 1456. The celebrated comet of Halley, of which the period amounts.
to about 76 years. Pingré I. p. 459.

16. 1472. From the observations of Regiomontauus, Pingré I. p. 475.

(15.) 1531. Halley's comet as observed by Apian. Pingré I. p. 488. See
also especially Halley’s ‘Tabule Astronomice, and his essay
there inserted, De motn cometarum elliptico.

17. 1532. Pingré I. p. 492. The once supposed identity of this comet
with that of 1661 must be abandoned. Méchain, Meém.
Prés. X. p. 333. Olbers in Hindenburg’s Magazine for Ma-.
thematics 1787. p. 440. '

18. 1533. Pingré L. p. 496. The total diversity of the two orbits suffi-
ciently shows the uncertainty of both. Struyck, 1753. p. 24.
Astron. Jahrb. Berl. 18009.

(9.), 1556. From the observations of Paul Fabricius between the 4th and
the 17th of March, which cannot be considered as certain ;
so that we can place little reliance on the resemblance to the
still less certain elemenis of the comet-of 1264. Pingré f.
p- 502.

Astronomical and Nautical Collections. 87

No. Year.
19. 1558. From three observations of the Landgrave of Hesse, and one of
¢ Cornelius Gemma, the latter being corrected in what is, very
probably, an error of the press. Gemma de Nature Divinis
Characterismis. Book II. ch. i. p. 33. See Berl. Astr. Jahrb.
1817, p. 176.

20. 1577. From Tycho’s Observations. Pingré I. p, 511.

21. 1580. Halley from Méstlin, Pingré from Tycho’s better obscrvations.
Pingré L. p, 521.

22. 1582, Both orbits uncertain, since they are founded only on three
observations of Tycho, of the 13th, 17th, and 18th of May ;
that of the 18th giving a double result, whence the two orbits
are derived. The first elements seem the most probable,
Pingré I. p. 544.

23, 1585. From the observations of Tycho and Rothmann. Pingré I.

. 550.
24, 1590. Tycho’ observations, from 23 February to 6 March. Pingré
. p. 554.

25. 1593. Bocrlat to the observations of Chr. J. Ripensis, at Zerbst.
Mem. Par. 1747, p. 562. Pingré I. p. 557.

26. 1596. Halley from Méstlin, Pingré from Tycho’s observations : hence
the latter elements are preferable. Pingré L. p. 562.

(15) 1607. Halley’s comet. Pingré [I. p. 3. Halley's Tab. Astr. First
supplement of the Berl. Astr. Jahrb. Mon. Corr, X. p. 425.

27. 1618. From Kepler's imperfect observations. Kepler de Cometis.
Pingré II. p. 4.

28. 1615. Bessel’s orbit is far the best, being founded on the observations

- of Harriot, Longomontanus, Cysat, and Schnellius. Berl.
Astr. Jahrb. 1808, p. 113.

29. 1652. From the observations of Hevelius between the 20th December
and the 8th January. Hevelius’s observations are not only
in the second volume of the Machina Celestis, which is very
rare, but also in his Cometographia,

30. 1661. The observations of Hevelius from the 3d February to the 28th

March. Machina Ceelestis [., and Cometographia. Mém.
pres X. p. 350.

81. 1664, Hevelius'’s observations in the Prodromas Cometicus, or better
in the Mantissa Prodromi, and in the Machina Cel. II, p.
439. Pingré LI. p. 10.

32. 1665. From Hevelius's observations from the 6th to the 20th April,
which are found in the Deser. Comet. 1665, Mantissa Prodr.
Com. and Mach. Ceelestis IL.

33. 1672. According to Hevelius’s observations from the 6th March to
the 21st April. Mach. Cel. IL. p. 593.

34. 1677. According to Hevelius’s observations from the 29th April to the
8th May. Flamstead observed it also twice. Mach. Col. IL.
p- 292, Flamstead Hist. Cel, Br. Ed, 1712, p. 103. Ed.
1725. I. p. 103.

35. 1678, From Lahire’s observations, which are only estimated, and from
the chart in the Hist. Cél. of Lemonnier, p. 238. See particu-
larly Struyck, 1753, p. 88, 39.

36. 1680, Euler's elliptical elements are to be considered merely as an
example of calculation, and require no further consideration.
It is only the elliptical orbit of Encke that is of any value at
present ; itis taken from his masterly prize essay on this comet

88

No. Year.

Astronomical and Nautical Collections.

(Zeitschrift fiir Astr. 1818), in which all the observations are

collected and discussed. The first orbit of Encke is the para-

bola which agrees best with the observations. The longi-

ee are reckoned from the mean equinox of the 15th Decem-
er, 1680.

(15.) 1682. Halley's comet: observed from 25th August to 19th September.

37.

38.
39.

40.
4).

42,
43.

44,

45.

4s.

A9.

Flamst. H. C. Br. I. p..108. Hevel. Ann. Climact. p. 120.
Halley in Tab. Astr. de mot. com. ellipt.

1683. According to Flamstead’s observations, from the 23d July to
the 5th Sept. Flamst. p. 110.

1684, According to Bianchini’s observations, from the Ist to the 17th
July. Phil. Tr. N. 169, p. 920. Acta erud. 1685. p.241.

1686. Seen first in August in the East Indies, then in September, in
Europe. Orbit not very certain. Pingré II. p. 28. i

1689. Very uncertain observations, Pingré IL. p. 29. »

1695. Burckhardt computed his orbit from manuscript observations
left by Delisle in the Dépdt de la Marine.. What was before
known of this comet Pingré has collected. p. 33. Conn. des
tems, 1817, p. 278... :

1698. The observations of Lahire and Cassini, the only ones that we
have of this comet, are deficient in accuracy. Anc. Mém. II.
p- 341, X. p.'742.. Mém. 1701, p. 117.

1699. Observed by Fontenay at Pekin, and by Cassini and Maraldi
at Paris. The observations extend from the 17th February
to the 2d March. Mem. Par. 1701, p. 47.

1701. From observations made by P. Pallu at Pau, which had lately
been recovered, and from the observations of P. Thomas, at
Pekin. Conn. des tems, 1811, p. 482.. Noel Obs. Phys.
Math. in India fact. p. 128.

1702. The observations between the 20th April and the 5th May not
very exact, Struyck, 1753, p. 50. Pingré II. p. 38. Mem,
Inst. UH. p. 28. Mon. Cor. XVI. p. 511.

- 1706. Cassini and Maraldi, from the 18th March to the 16th April.

Mem. Par. 1706, p. 91, 148. Pingreé IL, 39, Struyck, 1753,
5

p. 54.
. 1707. The observations extend from the 25th. November to the 23d

January, 1708. Mem, Par. 1707, p. 58S, and 1708, p. 89,
323. On the orbits see Pingré Li. p. 40. Struyek, 1753, p. 54.
The orbit of Hottuyn, given imperfectly by Struyck himself,
depends only on a construction.

1718, From Kirch’s observations, which are not particularly accurate.

Misc. Ber. III. p. 200. Phil. Trans. XXX. XXXII. Pingré
II. p. 41. Struyck Inleiding de Algemeene Geographie,
p: 295. Struyck, 1753, p. 57.

1723. Was seen in the East Indies as early as the 12th October. The
orbits are principally founded on the observations made be-
tween the 20th October and the 18th December by Halley,
Bradley, Pound, and Graham. Phil. Trans. XXXII. n. 382,

_p. 41, n. 897, p. 223. The second orbit, ascribed to Struyck,
is only found in the astronomical tables of Berlin. Pingre If.

-p. 42. Burckhardt’s hyperbolic. orbit. . Conn. des tems,
182i.

1729, Discovered by Father Sarabat the 31st July, 1729, and observed
until the 18th Jan. 1730. Pingreé IL. p. 42, Struyck, 1740, p.

Astronomnteat and Nautical Collections. 89

No. Year.

2 297, 1753, p. 58. Mém. Par. 1730, p. 284. The hyperbolic

and parabolic orbits of Burckhardt. Conn. des tems, 182].

51. 1737, Computed from Bradley's own observations, extending from
26 Feb. to 2 April. Phil. Trans. N. 446, p. 111. Pingré II.
p- 45. Struyck, 1740, p. 301.

52, 1737, The observations made at Pekin were published in the Mon.

Corr. XXL. p. 316. Conn! des tems. 1812, p. 409.

53. 1739. The observations are by Zanotti, from the 28th May to the 18th

August. N. Acta Erudit. 1740, p- 166. Comm. Inst. Bon. II.
p. ili, p. 73. Struyck, 1753, p. 64. The second orbit, by.Za-
notti, is only a first approximation, still remaining imperfect.

94. 1742. For the numerous observations of this comet see Pingré II. 47.

59. 1743, In part. very imperfectly observed. The observations are

j principally collected in Struyck, 1753, p. 75.
56. 1743. Observed imperfectly, and by Klinkenberg alone, from 18 Aug.
oa to 13 Sept. Struyck, 1753, p. 76,77. The observations,
which are also inserted by Pingré I, p- 52, differ sometimes
1° and more from the elements assigned.

57. 1744. Besides the observers and computers of this celebrated comet
quoted by Pingré, IT. p. 52, and Struyck, p. 78, some valuable
matter may be found in Chéseaux Traité dela Cométe, Laus.
1744, and Hiorter Trans. Swed. Acad. of Sciences.

_58. 1747. Discovered by Chéseaux the 13th Aug. 1746, and last ob-
served by Maraldi the 5th Dec. 1746. The orbits of Ma-
raldi and Lacaille are the best. Pingré II. p. 57. Struyck,
1753. p. 92.

59. 1748. Especially observed by Maraldi, Mém. Par, 1748, p. 229.

60. 1748, Observed only three ‘times imperfectly by Klinkenberg, the
19th, 20th, and 22d May. Struyck, 1753, p- 96. Bessel has
reduced the observations with greater care. Berl. Astr. Jahrb.
1809, p. 99. The imperfect elements, time of the Perihe-
lium, 1748, 22d April Q 9°, 24°, Inclination 76°, Least
distance 0.5, Motion retrograde, which Delambre as-
cribes to Burckhardt, and respecting which I can find no
further information, cannot possibly belong to either of the
computed comets of this year: so that they must have been
derived from the alleyed observations of the silly Kinderman,
which deserve no credit whatever.

61. 1757, Bradley's observations and elements are preferable to the rest.
Phil. tr. L. Part. i. p. 408. The other observations may be
found collected by Pingré, Mém. Par. 1757, p- 97.

62. 1758, Messier observed the comet from the 15th Aug. to the 2d Noy.

_Mém, Par, 1759, p. 154, 1760, p. 165, 463.

(15).1759. Celebrated and predicted re-appearance of Halley's comet.

Pingré IL. p. 63, gives references to works in which the ob-
servations and the elements may be found. Burckhardt's

___ orbit, preferable to all the rest. ‘Conn. des tems, 1819.

63, 1759. Pingré prefers his own elements. The comet was observed
from the 25th June to the 16th March 1760. Pingré I.

5 p- 68.
64. 1759. Observed from the 8th Jan. to the Sth Feb. 1760, Pingré II,
p- 70. ;
65. 1762, Discovered by Klinkenberg the 17th May, observed to the 2d
July. The refraction had been neglected in the reduction of

90 Astronomical and Nautical Collections.

No. Year.
the observations, and hence all the computed orbits varied
several minutes from the observations. Burckhardt reduced
them with greater care, and hence obtained the last elements,
which are more correct. Mém. Inst. VIL. p. 226. Mon.
Corr. XVI. p. 515. wit.

66. 1763. Discovered by Messier the 28th Sept., observed before the pe-

- vihelium from the 30th Sept. to the 25th Oct., after the
perihelium from the 12th to the 25th Nov. Pingré and Lexell
could not represent the observations sufficiently well by any
conic section. Pingré II. p. 106. Acta. Ac. Sc. Petr. 1780.
Pt. ii. p. 324. Burckhardt has corrected the observations of
Messier, which were distorted by some errors in the places of
Flamstead’s stars, and he has employed the observations of
St. Jaques de Silvabelle, which were made public more lately.
Mon. corr. X. p. 507. Conn. des tems. XIII. p. 344.

67. 1764, Discovered by Messier, and observed from 3d Jan. to 11th Feb.
The third orbit is that which has been corrected from all the
observations. Pingré IT, p. 74.

68. 1766. Discovered by Messier the Sth March, and observed for eight
days only. Pingreé If. p. 75.

69. 1766. Observed by Messier at Paris only five days, from the Sth to
the 12th April. La Nux at the Isle of Bourbon followed it
from the 29th April to the 13th May. Pingré IL. p. 76.
The imperfect observations of La Nux, Pingré could not
satisfactorily combine with the Parisian observations, and
Burckhardt has attempted to do this by means of an ellipsis.
Conn. des tems. 1821.

70. 1769. Discovered by Messier the 8th Aug., and observed before the
perihelium to the 15th Sept. ; after it from the 24th Oct. to
the Ist Dec. The principal observations are found Mem.
Par. 1769, p. 49; 1770, p. 24; 1775, p. 392. Maskelyne
Astr. Obs. I. On the various orbits, besides Pingré II.
p. 83, see especially Euler Recherches et Calculs sur la
comeéte, 1769; 4 Pet. 1770; the two rare works of Asclepi
De cometarum motu exercitatio ; 4 Rom. 1770, and De come-
tarum motu Addenda, Rom. 1770; besides Bessel’s excellent
prize memoir in the Berl. Astr. Jahrb. 1811. That Bessel’s
elliptic orbit is preferable to all others, scarcely requires to be
observed. The nodes and perihelium are determined by Bessel
as at rest with respect to the stars for the Ist Jan. 1769.

71. 1770. This comet, celebrated for an orbit deviating so greatly from
the parabolic form, was discovered the 14th June by Messier,
and observed till the 24 Oct. The observations have been
collected by Messier, Mém. Par. 1776, p. 597. The short
period of this comet, little exceeding five years and a half,
which appeared so paradoxical when it was first computed
by Lexell, was fully confirmed by Burckhardt’s investigations
in his valuable prize memoir. Mém. Inst. 1806, p.1. Therea-
son why the comet has not re-appeared since 1770, has been
very satisfactorily explained in Laplace's Mée. Cd. vol. [V.

-72. 1770. Was observed only four times at Paris, between the J0th and
20th of Jan. 1771. Mem, Par.1771, Pingré II. p. 90.

73. 1771, Discovered by Messier the Ist April, and observed by him

until the 19th June ; but by St, Jaques de Silvabelle at Mar~

Astronomical and Nautical Collections. 9]

No, Year. :
dias seilles till the 17th July. The orbit appears, according to the
investigations of Burckhardt and of Encke, to be truly hyper-
bolical. The parabola. of Encke, however, affords also
: results varying but little from the truth. Mon. Corr..X.
p- 510. Conn. des tems XIII. p. 344, Von Zach Corresp.
astr. 1820, Encke reckons from the mean equinox, Ist Jan.

1771.
‘74, 1772. Discovered by Montaigne the Sth March, observed by Messier
four times only, the 26th, 27th, and 30th March, and the 1st
April. The computation of the elliptic orbits was undertaken
on account of the similarity of the elements of the second
&, comet of 1805. These more correct investigations render
the identity of the two comets highly improbable, and it is
accordingly rejected by Bessel, as well as by Burckhardt, who
was able to employ the rediscovered observations of Mon-~
taigne. Mon. Corr. XIV. p. 73, 84. Conn. des tems 1811,

- 486. K

75. 1778. Dieddwerceh by Messier the 12th Oct. 1773, and observed until

“A the 14th Apr. 1774. Burckhardt, who employed also obser-
vations of St. Jaques de Silvabelle, found the orbit not
sensibly different from a parabola. Mém. Par. 1774—1777.
Acta Petr. 1779, p. 335. Conn. des tems XIII. p, 343. Mon.

ie Corr. X. p. 540.

76. 1774, Discovered by Montaigne the 11th Aug. observed till the 25th
Oct. Mem. Par. 1775, p. 445. Conn. des tems 1821.

77. 1779. Discovered by Bode the 6th Jan. observed till the 17th May.
Mem. Par. 1779, p. 318. Pingré, IL. p. 94, seems to prefer
the orbit of Dangos before the rest.

78. 1780. Discovered by Messier the 27th Oct. and observed till the
29th Nov. Mém. Par. 1780, p.515. Act. Petr. 1780, p. ii.
p. 347. Berl. Astr. Jahrb, 1784, p. 141.

79. 1780. Discovered the 18th Oct. by Montaigne and Olbers, and ob-
served very imperfectly three times only. The elements are
therefore very uncertain. Mém, Par. 1780, p. 515. Berl.
Astr. Jahrb. 1804, p. 172.

80, 1781. Discovered by Méchain the 28th June, observed till the 15th
July. Mém. Par. 1781, p. 349; 1782, p. 581. Berl. Astr.
Jahrb. 1785, p. 166.

$1. 1781. Discovered by Méchain the 9th Oct. observed till the 25th Dec.
Mém. Par. 1781, p. 360; 1782, p.587. Legendre Nouv.
Méthode, p. 41.

82. 1783. Discovered by Pigott the 20th Nov. observed till the 21st Dec.

Mém., Par. 1783, p. 123, 648, Phil.tr. LXXIV. Conn. des
tems 1788. But respecting Burckhardt’s orbit, sec especially
beaten Conn. des tems 1820, p. 305. ;

‘83. 1784, Seen by Dela Nux at the Isle of Bourbon the 15th Dec. 1783,

in Paris not till the 24th January, and observed there till the
11th March, Afterwards it was again visible, and observed
from the 9th to the 26th of May. Mém. Par. 1784, p. 313,
358. The first elements are the most correct.

The comet hitherto inserted in the tables, as the second of
1784, is a shameful forgery of the Chevalier Dangos, as Pro-

ad fessor Encke has shown in the Corresp. Ast. for 1820. Cah. v.

p- 456. ™ ‘A ' -

92 Astronomical and Nautical Collections.

r
No. Year.

84, 1785. Discovered by Messier and Méchain the 7th Jan. observed till
the Sth Feb. Mém. Par. 1785, p.646. Berl. Astr. Jahrb.
1789, p. 142. Conn. des tems, 1788.

85. 1785, Discovered by Méchain the 11th March, observed till the 17th
Apr. Mém. Par. 1785, p. 646. Berl. Astr. Jahrb. 1789,

p. 143.

86. 1786. Was discovered by Méchain the 17th Jan. and could only be
observed once more on the 19th, by Méchain and Messier.
Mém. Par. 1786, p. 95. But since the identity of this comet
with those of the years 1795, 1805, and.1819, has been de-
monstrated, Encke was able todetermine the orbit from these
two observations. Berl. Astr. Jahrb. 1822. Corresp. Astr.

1819. Conn. des tems, 1819, p. 224.

87. 1786. Discovered the 1st Aug. by Miss Caroline Herschel, observed
till the 26th Oct. Mem. Par. 1786, p.98. Maskelyne, Astr.
Obs. II. p. 29. Ephem. Milan. 1789. Conn. des tems, 1789.

88. 1787. Discovered by Méchain the 10th April, observed at Paris till
the 20th ; at Marseilles till the 26th May. Mém. Par. 1787,
p. 70. Conn, des tems, 1790. . Berl. Astr. Jahrb. 1791.
La Nux observed it at the Isle of France from the 25th May

; to the 21st June.

$9. 1788. Discovered by Messier the 25th Nov. observed till the 29th
Dec. Mem. Par. 1789, p. 663. Conn, des tems. 1791.
Berl. Astr. Jahrb. 1793.

90. 1788. Discovered by Miss Herschel the 21st Dec.: observed last by
Méchain the 18th Jan. 1789. Phil. tr. LXX VII. p. 1. Mém.
Par. 1789, p. 681. Maskelyne Astron. Obs, for 1788. Berl.
Astr. Jahrb. 1793. p. 119.

91. 1790. Discovered by Miss Herschel the 7th Jan.: observed only four
times ; the 9th, 19th, 20th, and 21st Jan. Mém. Par. 1790,
p. 309. The first orbit agrees best with the longitudes ; the

; second with the latitudes.

92. 1790. Discovered by Méchain the 9th of Jan. and observed till the
22d. Mém. Par. 1790, p. 313. Conn. des tems, 1792, p. 355.
Berl. Astr. Jahrb. 1794.

93. 1790. Discovered by Miss Herschel the 17th April, and observed till
the <9th June. Mém, Par. 1790, p. 320. Conn, des tems
1792, p. 355. Englefield on Comets, Lond. 1793, p. viii.

94. 1792. Discovered by Miss Herschel the 15th of December 1791: ob-
served last by Maskelyne on the 25th Jan. 1792. Berl. Astr.
Jahrb. 1795, p. 184, 201; 1796, p. 148; Conn. des tems
1793, p. 374, Englefield on Comets. The first elements, by
Méchain, are those which have been corrected from all the
observations.

95. 1792. Discovered by Méchain the 10th Jan. 1793; also by Piazzi;
observed till the 19th Feb. Piazzi della spec. astr. book v.
Berl. Astr. Jahrb. 1797, p. 136 ; 1799, p. 192. Conn. des
tems, 1795, p. 286.

96. 1793, Discovered by Messier the 27th Sept. observed till the 11th
Oct.: then seen again the 80th Dec. and observed till the 4th
Jan. 1794, Conn. des tems, 1795, p. 287.

(To the best of my knowledge, Messier’s observations of this

comet, as wellas of some others, have not yet been printed,
Their entire publication would be highly desirable.)

Astronomical and Nautical Collections. 93

?
No. Year.

97. 1793. Discovered by Perny the 24th September, observed till the 3d
December. Conn. des tems, 1795, and especially Conn. des
tems, 1820. Burckhardt leaves it doubtful whether this comet

: is or is not identical with that of 1783.

(86.) 1795. Discovered by Miss Herschel, the 7th November, and ob-
served till the 27th. The observations chiefly rather inac-
curate. ‘This is the second appearance of Encke's comet.
Phil. Trans. 1795. | Berl. Astr. Jahrb. 1799. 1814. More
especially see Berl. Astr. Jahrb, 1822, p. 183. Von Zach
Corr. Astr. 1819. Encke computes from the mean equinox
of the 18th November, 1795.

98. 1796. Discovered by Olbers the 31st March, and observed till the 14th
April. Berl. Astr. Jahrb. 1799, p. 106.

99. 1797. Discovered by Bouvard the 14th August, and observed till the

: 3lst. Berl. Astr. Jahrb. 1800. Allg. Geogr. Ephem. I. p-
127, 366, 604.

100. 1798, Discovered by Messier, the 12th April, and observed till the
24th May. Mém. Inst. IL p. 430. Alle. G. Eph. I. p. 679,
692, 694. II. p. 79, 95. Berl. Astr. Jahrb. 1801, p. 231.

101. 1798. Discovered the 6th December by Bouvard, and the sth by
Olbers, and only observed till the 12th. Berl. Astr. Jahr L
1802, p. 195. Allg. G. Eph. III. Conn. des tems, 1804, p-

: 373.

102. 1799. Discovered the 6th of August, by Méchain, and observed till the

" 2ist October, Ally. G. Eph, IV. Berl. Astr. Jahrb. 1802,
~ 1803. Mon. Corr. I. IT.

103, 1799. Discovered the 26th Dec. by Méchain, and observed by him till

of the 5th Jan. 1800, Mon. Corr. I. p. 191, 299, Mém: Inst. IT.
p- 153. Berl. Astr. Jahrb. 1803. Conn. des tems, 1804, p-
376. Méchain thinks that this comet may possibly have been
identical with that of 1699.

104, 1801. Discovered almost the same hour by Pons, at Marseilles, and
Messier, Méchain, and Bouvard, at Paris, on the 12th July:
observed last by Méchain, the 23d. Mon. Corr. IV. p. 179.
Berl. Astr. Jahob. 1805, p. 129. Conn. des tems, An. XIII.
p. 344, 484.

105. 1802. Discovered by Pons the 26th August: observed till the 3d Octo-
ber. Mon. Corr. VI. Conn. des tems. An XIII, p- 236,
374, Berl. Astr. Jahrb. 1805, 1806, p. 129.

106. 1804, Discovered by Pons the 7th March: observed till the Ist April.
ma Conn. des tems, XV. p. 374: 1808, p. 336. Mon. Corr, IX.
Berl. Astr. Jahrb. 1807. ;

(86.) 1805, Third appearance of the comet of Encke. Discovered at the

same time by Bouvard, Pons, and Huth, the 20th October -
observed till the 15th, and seen on the 19th November. Mon.
Corr. XIII. XIV. Conn. des tems, 1808, 1809. Berl. Astr.
Jahrb. 1899. But especially see Berl. Astr. Jahrb. 1822,
1823. Corresp. Astr. 1819.

107. 1805, Discovered by Pons the 10th Nov. and observed till the 9th

rit Dec. Its supposed identity with the comet of 1772 has given
oceasion to many computations, ‘This identity has not been
confirmed ; but Gauss found that the observations agree better
with any ellipsis that has its greater semiaxis longer than 2,82,
than with a parabola. Mon, Corr. XIU. XIV, XXVU.

&:

Gg,

No.

108.

109.

110.

111.

113.

114.

116.

117.

Year.

Astronomical and Nautical Collections.
t

p-360, 490. Berl. Astr. Jahrb. 1809. Conn. des tems. 1808,
1809. ‘ :

1806. Discovered by Pons the 10th November: observed first till the

20th Dee., and then again from the 17th Jan. to the 12th Feb.
1807. Mon. Corr. XV. XVI. Berl. Astr. Jahrb. 1810. Conn,
des tems, 1810. p. 298, 1819.

1807. Great comet. Observed from the 22d Sept. 1807 to the 27th

March, 1808. Most of the observations are collected in Bes-
sel's Untersuchungen tiber den grossen cometen, 4, Kénigs-
berg, 1810. Besides this classical work see also Mon. Corr,
XVI. XVII. XVIII. XIX. Berl. Astr. Jahrb. 1811, 1812,
1813, 1814. Cacciatore della cometa di 1807. Conn. des
Tems, 1809, 1810, 1811, and Phil. Trans. 1808.

1808. Discovered by Pons, the 24th June, and somewhat uncertain,

1810.

. 1811.

‘Isil.

1812.

especially with respect to the declinations: observed only at
Marseilles, from the 26th June till the 3d July, Mon. Corr.
XVIIL. p. 245, 359. Berl. Astr. Jahob. 1812, p. 129. j

Discovered the 22d August by Pons, and observed very doubt-
fully at Marseilles only from the 29th Aug. to the 21st Sept.
Mon. Corr. XXIIL. p. 802., XXIV. p. 71. Berl. Astr. Jahrb,
1814, p. 179.

Discovered by Flauguergues the 26th March, and observed in
Europe before the perihelium till the 2d June, after the peri-
helium from the 20th August to the 11th Jan. 1812: lastly
rediscovered by Wisniewski, at New T'sherkask, the 31st
July, 1812, and observed again from the Sth to the 17th of
August. Upon this great comet, very remarkable even in its
form, and observed by almost all astronomers, besides the
Mon. Corr. XXUI. XXIV. XXV. Phil. Trans. 1812. Berl.
Astr. Jahrb. 1815, 1816. Conn. des tems, 1820, and so
forth, see especially the excellent treatise of Dr. F. W. A.
Argelander, Ueber die Bahn des grossen cometen von 1811,
4, Kénigsberg, 1822. The orbit of Argelander, inserted in
the table, is that which he considers as the most probable : but
the observations made at the different times of the comet's
appearance could not be quite satisfactorily represented by any
orbit governed by the Keplerian laws. Argelander reckons
from the place of the mean equinox the 12th Sept. 1811.

Discovered by Pons the 16th November, and observed last at
Bremen, the 16th February, 1812. Conn. des tems, 1820.
Mon. Corr. XXIV, XXV, and especially XXVII. Nicolai
reckons from the mean equinox on the Ist Jan, 1812.

Discovered by Pons the 20th July, and observed till the end of
September. Mon. Corr. XXVII. XXVIII. Con. des tems,
1820: but see especially the Zeitschrift for 1817. Encke
reckons the longitudes from the mean equinox of the Ist Sep-
tember, 1812.

5. 1813. Discovered by Pons the 4th February, and observed till the 11th

March. Mon. Corr. XXVII. Conn. des tems, 1820.

1813. Discovered by Pons at Marseilles, and Harding, at Gottingen,

the 2d and 3d of April: observed till the 29th. Conn, des
tems, 1820. Mon. Corr. XXVU. XXVIII.

1815, Discovered by Olbers the 6th of March: observed last by Gauss,

the 25th of August. Bessel has taken the perturbations into

Astronomical and Nautical Collections. 95

No. Year.
38 -aecount for his elliptical orbit. Period, according to Nicolai,
74.7893 years ; according to Bessel, 74.04913. Bessel com-
putes, that taking all the perturbations into account, the
comet will reach its periheliam again in as early as 1887, Feb.
9.4, that is $24.5 days earlier than the period of the simple
elliptic orbit. Berl. Astr. Jahrb. 1818, 1819. Observations
at Konigsberg, If. Zeitschrift for 1816. Trans. Berl. Acad.

. 1812, 1815. Math. Class. Wonn. des tems, 1520. Bessel
reckons the longitudes from the mean equinox of the Ist Jan.
Nicolai from the 26th April, 1815.

118. 1818. Discovered by Pons the 26th Dec. 1817: observed last at Bre-

men the Ist May 1818. The comet was on account of the
faintness of its light very dificult to be observed, and ap-
peared to be gradually dissolved. Berl. Astr, Jahrb. 1821.
Zeitschrift for 1818. Conn. des tems, 1821.

119. 1818, Discovered by Pons the 29th Nov. 1818 ; afterwards by Bessel
the 22d Dec. Last observed by Harding the 30th Jan. 1819.
Berl. Astr. Jahrb. 1821, 1524, Conn. des tems, 1821. Corresp.
Astr. IL. p. 187.

(86.) 1819, Reappearance of the celebrated comet of Encke, by which its
short period of 1207 days was first ascertained. Discovered
by Pons the 27th Nov. 1818: observed last the 12th Jan.
1819. Only the last elliptic orbit of Encke is to be considered
as the true one. Corr. Astr. 1819. Berl. Astr. Jahrb. 1822,
1823. Conn. des tems, 1522. Encke reckons the longitudes
from the mean equinox of the 1st Jan. 1819.

120. 1819. Appeared suddenly in Europe emerging from the sun’s rays in
the beginning of July, of a considerable magnitude. Last
observed in October at Dorpat and at Bremen. Is remark-
able, because, according to the elements, it must have passed
over the sun’s dise on the 26th of June. Corr. Astr. 1819.
Berl. Astr. Jahrb. 1521, 1822. Conn. des tems, 1822.

121. 1819. Discovered by Pons the 12th June, and only observed at Mar-
seilles and in Milan till the Joth July. Only the last orbit,
by Encke, agrees with the observations, which cannot be re-
presented by any parabola. Corr. Astr. 1819. Berl. Astr.
Jahrb. 1822, p. 243; 1823, p. 221. Efem. Milan. 1820.
Encke computes from the mean equinox of the Ist Jan. 1819.

122, 1819. Discovered by Blanpain at Marseilles the 28th Nov. : observed

_ last at Milan the 25th Jan. 1820. Observed also at Bologna,
and especially at Paris. he great deviation of the orbit
from a parabola is not to be doubted ; but the limits of the
time of revolution have not hitherto been found assignable,
on account of the too short interval between the observations
which have been published, and which are in some degree of
deubtful accuracy ; those of Marseilles not having been ob-
tained by the most earnest entreaties and demands. Corresp.
Astr. 1820. Berl. Astr. Jahrb, 1824, Conn, des tems, 1824.
Encke reckons from the mean equinox of the Ist June, 1820.

123. 1821, Discovered at the same time on the 2lst Jan. by Nicollet at
Paris, and by Pons at La Marlia. Was observed in Europe
till the 7th March, and after the perihelium, from the Ist
April till the 3d May at Valparaiso, by Captain Basil Hall,
Lieutenant W. Robertson, and Mr. H. Forster. Its apparent

Astronomical and Nautical Collections.

motion was very slow throughout the time of the European
observations. Brinkley’s first elements are founded only on
the observations at Valparaiso: the second he has com-
puted from the observation of the 30th January at Bremen,
and those of Capt. Hall, made the Sth April and the 3d May.
Rosenberger was able to represent both the European and
the American observations sufficiently well by his parabola.
The rest of the ‘vrbits are founded on the European observa-
tions alone, The orbit seems to differ very little from a true
parabola. Corr. Astr. 1820. Conn. des tems, 1824, Berl.
Astr. Jahrb. 1824. Phil. Tr. 1822, Pt. i. Edinb. Phil, Journ.
N. xiv. p.382. Schumacher Astr. Nachr. N. 2, p. 17. N. 11,
p. 166. N. 24, p. 425.

124, 1822. Discovered by Gambart at Marseilles the 12th May, by Pons at

Marlia the 14th, and by the Oberlieutenant Biela, at
Prague, the 16th: observed till the end of June. Zach
Corresp. Astr. 1822, cah. ili. iv. v. Schumacher Astr. Nachr.
N. 19, p. 298. N. 20, p. 309. Berl. Astr. Jahrb. 1825.

(86.) 1822. Orbit corrected by Encke from Riimker’s observations at Pa-

ramatta. Schumacher Astr. Nachr. N. 27, p. 39. Thelon-
gitudes relate to the mean equinox of the 24th May.

125. 1822, Discovered the 13th July by Pons, at Marlia: observed till the

22d October. Only the second ellipsis of Encke is founded
on the whole apparent are described : but the second parabo-
lic orbit of Nicolai, and the third of Hansen represent also
the whole of the observations hitherto published in the most
satisfactory manner. Perhaps we may expect to receive from
the Cape of Good Hope, or from New Holland, some observa-
tions of the two last comets, as well as of that which was dis-
covered on the 31st May, by Pons, at Marlia, near 6 Piscium,
and which was little observed in Europe, and has not yet been
computed, Zach. Corr. Astr. cah. v. Schumacher Astr.
Nachr. N. 20, p. 307.; n. 21. Suppl. ; N. 22, p. 361, and 1.
Suppl. ; N. 23, p. 393, and Suppl. ; N. 24, Suppl. Nicolai
supposes the mean equinox of the 23d Oct.; Hansen in the
second orbit, the Ist Sept. ; in the third the Ist October, and
Encke, the 25th Oct. 1822. [See also Gambart in Conn. des
tems, 1826. T'r.}

ii. Further Remarks on the periodical Comer (86 Olb.) with conjec-

tures on the effect of a resisting medium.

By Professor Encxr. Bode's Alm. 1826, p. 124.

The observations of Mr. Riimker have removed every possible
doubt respecting the identity of the comet, and made it certain
that future Astronomers will be able to recover it even if it should
remain invisible for several revolutions. Fortunately, however,
there is no reason to apprehend that it will escape us in its next

Astronomical and Nautical Collections. 97

visit. Dr. Oxzers first pointed out to me that if it passed the
perihelium later than the 10th of September, it will be visible to
Europeans in August. From a cursory computation of the per-
turbations, I find that its perihelium will be about Sept. 16.4, and
its places will be nearly these:

A.R. Decl. Log. Dist.
1825 aatiy iF iets © =
Aug. 1.6 82 31 32 1N 0.023 0.162
6.6 90 23 32. 9 9.988 0.141
11.6 99 1 3] 44 9.948 0.123
16.6 108 19 30 36 9.903 0.107
21.6. 118 9 28 37 9.852 0.097
26.6 128 14 25 40 9.792 0.092
31.6 138 23 21 46 9.724 0.093

Its next return to the perihelium will be in Dec. 1828, or per=
haps in the beginning of January 1829: and it will then be easily
visible, unless its light should prove to be gradually dimi-
nishing.

In attempting to compute the perturbations, it becomes necessary
to employ higher powers of the quantities concerned than those
which are sufficient for the planets, and no precautions or suppo-.
sitions respecting the masses of the disturbing bodies are capable
of representing the successive revolutions from each other without
errors of several degrees. For example, we represent the five
perihelia of 1786, 1795, 1805, 1819, and 1822, most conveniently
by taking the mass of Jupiter 71; less than that which is assigned
by Laplace: but errors exceeding a whole day in the interval will
still remain: and the middle three of the five considered alone
afford still greater irregularities, although the actions of the planets
which are neglected would have a very inconsiderable influence on
this combination.

Comprehending the effects of 8, 9, and ©, the best result is
obtained by increasing the mass of Jupiter about 4: but the ele-
ments thus corrected give the perihelium of 1786 two days too
early, and that of 1822 a day and a half too late: nor will any

Vou. XVII. H

98 Astronomical and Nautical Collections.

other planetary perturbation, that ca be imagined, enable us to
remove this error.

I therefore think myself entitled to consider it as demonstrated,
that an alteration of the supposed masses of the planets alone is
not sufficient for the purpose; and in the predictive computation of
the places for 1822, which has now been verified, I was induced by
this conviction to assume an empirical correction proportional to
the square of the time.

Such a correction of the epoch corresponds to a mean angular
motion increasing directly as the time, and points at once to the
possibility of an explanation of its foundation. From Newton
down to Laplace, a number of the most acute mathematicians have
investigated the influence which any substance, scattered through
space, might have on the motions of the heavenly bodies. The
resistance of such a medium would necessarily occasion a continual
shortening of the greater axis, and consequently an increase of the
mean motion, and a diminution of the eccentricity; while the
longitude of the perihelium would undergo only periodical changes
compensating each other in the time of a revolution; and the
nodes and inclination, which affect only the plane of the orbit,
would be perfectly exempted from its influence. Now these are
exactly the changes which are observable in our comet; for the
decided change of the eccentricity, in the year 1822, may at least,
in great measure, be attributed to some extraneous cause: though
the earlier observations would not agree so well with a rapid
change of this element.

Before it had been shown by these computations that the various
returns of the comet could not be reconciled to each other without
some such hypothesis, Dr. Olbers had already pvinted out the pro-
bability of a similar alteration in a letter to Mr. von Lindenau.
He wrote again to me on the subject in these words: ‘ ‘The ex-
emption of the dense and solid bodies of the planets from any sen-
sible effects of resistance, in the interplanetary spaces, proves
nothing with respect to comets, which occupying, perhaps, a
volume 1000 times as great, may have masses 1000 times as
small: and with respect to this comet of ‘ Pons,’ such a resistance

Astronomical and Nautical Collections. 99

seems to be almost demonstrable @ priori: for it moves, during a
considerable portion of its period, in that part of the open space of
the system, in which the visible substance of the zodiacal light, or
solar atmosphere, is found. It is this same comet, through the
middle of which Herschel, on the 9th Nov. 1795, saw a small
double star of the twelfth or thirteenth magnitude, with very little
diminution of its brightness. This fact seems to demonstrate that
the density of the comet bears some finite proportion to that of the
zodiacal light, and that the substance causing this light may afford
some sensible resistance to the motion of the comet. If then all
the rest of the space surrounding us were to be considered as per-
fectly void and free from resistance, which I do not believe, still
the substance of the zodiacal light, which does certainly exist, is
sufficient to explain the phenomena of a diminution of the periodi-
cal time, and of the eccentricity of the orbit.”

Dr. Olbers further remarks that this ethereal medium may na-
turally be supposed to revolve with the planets from west to east,
so as to exhibit little or no influence on their motions, while those
of the comets, being more discordant, may suffer a very material
disturbance from its resistance.

[Upon a probable supposition respecting the law of the density
of the resisting medium, Professor Encke proceeds to calculate the
places of the comet for 1795, 1805, and 1819, in such a manner as
to reduce the sum of the errors to less than half their amount upon
the most advantageous suppositions respecting the planetary per-
turbations. For 1822 the improvement does not appear to be so
considerable. ]

The times of the successive passages through the perihelium, as
affected by the perturbation, are assigned in this table, and those,
which have been observed, are distinguished by an asterisc.

*1786 Jan. 30.1 Parisian M.'T. *1805 Noy. 21.5
1789 May 18.7 1809 March 11.9
1792 Sept. 4.1 1812 June 26.3

*1795 Dec. 21.4 1815 Oct. 12.7
1799 April 11.1 *1819 Jan. 27.3
1802 Aug. 1.9 *1822 May 24.0

100 Astronomical and Nautical Collections.

The comet of 1766, which has been suspected to be the same, is
recorded to have been very bright to the naked eye, and its motion
was retrograde.

iii. Comparison of the Nuw Tasirs of Refraction with
Observation.

Rerractions observed by Mx. GroomBrince. (Coll. XTIT.i.)

M.Corr. Red. to Ivory

Obs. App. Alt. Fahr. forl® Refr. B.30 469.5 N. A. Error. 509. Error”
16 218 49.6 49.2 $.5 2223.3 99 39.7 22 16.2 —16.5 22 10.2 —10.8
25 @& 30. 9,5,.38.1 3.3. .91,38.0,.91 10.2 2), 6.1 — 4.1.20 58.7 = 7.2
17 2 0 8.1 52.9 2.7 1811.1 18 28.3 18 28.5 +0.2 1819.0 — 0.4
[44] 217 35.2 31.9 9.4 17 38.9 17 4.0 1710.7 + 6.7 17 1.5 F 2.6
13 2 3053.4 56.7 2.3 1551.6 1615.0 1618.6 + 3.6 16 8.5 — 2.3
9 241 2.2 56.3 2.1 15 18.3 15 38.8 15 39.3 + 0.5 15 29.9 — 5.1
5 2.51 34.5 28.7 2.1 15 32.7 1455.3 15 2.6 + 7.3 14 53.3 414.2
12 $ 229.9 38.9 2.0 ..14 44.7 14 99.5 14 27.0 —-2.5 1418.0 + 2.7
10 $6 50;9 54.8 2.0. 19 58:5 14.10... 14.19.98 070) 14) beater 1).
8 $3 53°87c5, 89.8 1.6. 1217.4. 12 6.7-,12 6.2 — 0.512 Ove 7. 2,6
10 “47 “ova "s90°8" 1.56 12+ 1.6 11°40.2- 11 36-2 — 4.0- Itol.9 —t 3.5
15 449 8.7 °38.6 1.33 10 21.7 1011.2 1016.4 + 5.2 1011.8 + 3.8
12 455 27.2 43.5 1.30 10100 10 5.4 10 5.2 —0.2 10 1.04 1.1
16 455 55.7 38:8 1680 10 19.8 109%2.1..10..4,4.>.2.28 On Osim, 5. 1
+56.8 + 62.6

+ 1.2 +25.4

7 5 917.7 58.2 1.25 999.8 944.4 943.0+1.4 9 39.2 #06
11 5 2758.5 ‘33.8 1.20 928.5 913.8 913.8 +0.5 911.7 + 2.1
13 5 44 33.2 53.8 1.13 841.4 849.7 853.04 3.3 849.3+0.3
13 5 4755.9 33.6 1.12 857.5 843.1 847.6 + 4.5 8 44.8 + 1.1
29 613 12.7 38.5 1.05 820.8 812.4 8162+ 3.8 814.1 +1.8
23 6 30 26.4 58.3 .98 746.4 1757.5 757.1— 0.4 7551+ 1.7
7 YG 85.0887 <9 67 g1s4 (7 19.8!) 7 20.5. Oly © Woeeeseol 7
94 792 13.6 61.8 .88 658.0 711.5 7 60—5.5 7 5.2 + 2.3
13 8 20 21.3 39.9 .82 636.5 622.9 620.8—2.1 619.9 + 2.0

Int. Int. 50°

Br.22 7 $13 66.0 .89 6542 7 84 7 96+1.2 7 8.8
P.156 1343 0 45.0 .47 $57.0 354.6 354.6 0.0 3 54.9
The mean refractions of the Nautical Almanac are here com-
pared with the observations as reduced to the standard tempera-
ture of 46.°5 for the exterior thermometer, by taking a mean of the
English and French corrections, for the reasons explained in the

Astronomical and Nautical Collections. 101

thirteenth number of these collections. Mr. Ivory not having pre-
cisely assigned the temperature at which his tables may be sup-
posed to represent the results of the exterior thermometer, the
errors of the New Tables have been copied from his own comparison
of these tables with Mr. Groombridge’s observations, and it is
obvious that the New Tables, thus compared with the phenomena, do
not at least possess any advantage over those of the Nautical Al-
manac ; though they can scarcely be said to be decidedly inferior,
with regard to the lower altitudes: but at 45° it appears to be
highly improbable that the refraction, at the temperature of 50°, or
even of 48°, can be so much as 57.36.

. Professor Brssxx has given us, in the Berlin Almanac for 1826,
the results of his latest observations on the refractions near the
horizon, which show, very satisfactorily, what was. perfectly well
known before, that his table is founded upon an inadequate theory,
and that it is of no particular use where any correct theory at all is
wanted. The comparative results of the different determinations
may be exhibited in a short table.

Comparative Results, Barometer 30.

N.A. N. A.

Alt. apn ai 5z° Int. Ivory Dift- Bessel F, A. tet Corr.

oO / / “a , uw J Mu 7 ‘ “ v “ uN

0 0 3351 33 34.8 34 17.5 +42.7 36 36.1 36 0 —36

0 30 28 37 28 24.8 28 40.8 +16.0 29 51.4 29 27.3 —24.06
1 0 2425 2415.6 2421.8 +6.2 24 58.2 24 44.6 —13.60
1-30-21 7 20 59:2 20 59:6 +0.4 21 18.3 21° 7.9 —10.35
2 0 1829 18 22.6 1819.6 —-3.0 18 28.8 18 23.3 -— 5.46
230 1621 1615.6 16 10.89 —4.7 1615.1 1613.9 — 1.19
8 0 14 35 14 80.4 14 26.04 —4.4 14 27.5 14 26.1. — 1:42
830 18 7 18 3.0 12 59.51 —-3.5 1259.5 12 58.7 — 0.77
4 0 11 52 11 48.6 11 47.15 —1.1 1146.4 11 48.4 + 1.97
430 10 50 1046.9 10 46.03 —0.9 10 44.9 10 48.2 + 3.30
5 0 958 955.2 9 583.84 —1.4 952.5 9 52.4 + 0.05
6 0 8 82 829.7 8 29.80 +0.1 8 28.5 Berl. Astr. Jahrb.
7.0. 227 7.25.0, .7 25.40 +0.4. |7 24.2 1826.

8 0 635 683.3 6 34,68 +0.4. 6 33.6

9 0 554 5.52.5. 5 58.79 +1.8 . 5 52.8
10 0 520 518.6 520.19 +1.6 519.4
15 0 8 34.8 8 93.4. 384.70 +1.3 8 84.3

102 Astronomical and Nautical Collections.

N. A. Nw A.
Alt. es fe 52° Inte Ivory Diff. Bessel F. A.
oO 0 238.72 381 239,16 $1.2 ‘2 28.9
anh 9 4.29 5.1 2 4.65 +1.0. 2° 4,4
30 0 1 40.5 1 40.1 1 40.85 +0.7 1 40.7
35 0 23.0) 1) 225% 1 23.25 +0.5 123.1
40 0 1, [9.841 $9.0 1 9.52 +0.5 1 9.4
45 0 58.1 57.9 58.36 +0.5 58.27
50 0 48 8 48.6 48.99 +0.4 48.91
60 0 $3.6 33.0 33.72 +0.2 33.67
70 O SN ty lie 3 Ness 21.26 +0.16 21.23
80 0 10.2 10.2 10.30 +0.10 10.29

The results of the Nautical Almanac are reduced to 52°, im
order to compare them the more readily with those of Mr. Ivory.

For the mean probable error of a single observation, Professor

Bessel and Mr. Rosenberger have found at
Alt. Error Alt. Error Alt. Error

oO r a“ °o V/ , a“

630 26.0 230 53 £30. 2.0
prego spg7eod3g)%6 23, oP syg me, 214.7
130. 10.6.....3.30..sid@ Gadelpathondiian
2 0 Py ea ae oa ae Boe Ge

And the probable ultimate errors of their determination of the
mean refraction, at 1° and 2°, are found to be 2”.5 and 1” re-
spectively. :

With respect to the refractions below the horizon to which the
table of Bessel extends, it will always be amply sufficient to take
the mean horizontal refraction, and to increase it by its excess
above the refraction computed for an altitude equal to the de-
pression, and for the actual state of the atmosphere; except that
if the temperature at the surface of the sea were known to be ele~
vated or depressed, it would be proper to correct the mean hori-
zontal refraction accordingly.

The whole of this comparison has been instituted in order to
ascertain the propriety of retaining or suppressing the remark sub-
joined to the table in the Nautical Almanac, that it ‘‘ appears to
agree more perfectly with the latest observations than any other table
that has been published,” explained as it is by the admission in
the preface, that the “ deviation from the French tables in the

Astronomical and Nautical Collections. 103

mean value of the refraction,” is altogether inconsiderable. If the
new table had been decidedly shown to exhibit results more ex-
actly conformable with the actual determinations of astronomers
than those of the Nautical Almanac, it would have become the
duty of the editor to adopt them; but for the present there can be
no question that such a change would at least be premature.

iv. Note on Rurraction, addressed to Professor SCHUMACHER.

My dear Sir,

I was much surprised the other day to observe, that in copying
the explanation of my Table of Refractions from the Nautical Al-
manac, you had omitted, without assigning any reason, the words
“¢ which would be more consistent with the theory;” an expression
which I had employed in speaking of the use of the external ther-
mometer, in preference to the interior.

I am the more disposed to remonstrate with you on this occa-
sion, because I observe that a great number of astronomers, and
among them some who do not usually act without reflection, have
inconsiderately taken it for granted that the correction ought to be
made according to the height of the interior thermometer, as
nearest to the place of observation.

Now, with regard to the theory, it is perfectly obvious, that the
computation extends only to such changes of density as take place
between the different strata of the atmosphere considered as hori-
zontal; and that its results must necessarily terminate where this
regular constitution of the atmosphere ends; that is, owtside the
observatory, or other building, containing the instruments; while
the change of density between the external and internal air, taking
place in general at surfaces more nearly vertical than horizontal,
at least when the object is but little elevated, and certainly never
at horizontal surfaces, will either have no effect at all in increasing
the refraction, or as great an effect at higher as at lower altitudes;
so that this little irregular addition or diminution can never require
to be considered as a part proportional to the whole original mean
refraction.

With regard to practice and observation, I need only refer to

104 Astronomical and Nautical Collections.

Mr. Delambre’s remarks in the Connazssance des Tems, for 1819,
where he shows that for Mr. Groombridge’s observations, the
mean error of the exterior thermometer is only five sixths as great
as that of the interior. Rishi

v. General Results of Observations on the Dipping Needle.
By W. Scorzssy, Jun. Esq.

1223 «Time Place Mean dip,
Mar. 29 Liverpool 71°33' 0”
June 10 La.71°31' 14” N. Lo, 12° 7'15" W. 78 36
July 5 71 38 0 17 37 0 79 07 or

79 67 (M.)

The mean dip is the mean result of observations with and with-
out a sphere on the needle: the last result, (M.) is obtained by
the formula of Professor Mayer.

vi. Elements of the Comer of 1823-4. By various Computers.

1. The first received by the Editor were from Mr. J. Taylor of
the Royal Observatory, Greenwich.. 2. The second are by Pro-
fessor Nicolai Schumacher, Astr. N.N. 48. B. 3; giving the greatest
error in A. R. + 18”,indecl.+ 11”. 3. The third by Mr. Hansen,
A. N. 48, B.3. 4. The fourth by Carlini. 5. The fifth by Dr.
Brinkley. 6. The sixth by Mr. Richardson, of Greenwich.

a 1823 Dec. 9.36974 Greenwich
9.4380 Manheim

7 spe 9.47193 Altona
Passage of Perihelium ( 4° 9.4792 Greenwich
5. 9.2168 Greenwich
6. 9.4521 Greenwich
1. 302° 56’ 34’ 4, 303° Ae
Longitude of 9 4 2. 303 1 18 5. 303 0 40
Sey OVSarx 47122 6.-..803,, -1p¢48
so» 28)48,, 64 4, 1. 284/26 43°8
— Periheliumy 2. 23 43 45 6. 29. 18 BO
3. 387 99! 56 6. 28 20 6
if 1. 9.38598242 4, 9,.3545000
Log. nearest distance, 2. 9.3579600 5. 9.3689400
| 3. 9.3553934 6. 9.3536855
Le: 75° 6545" 4.28 96° \A2lin SOY
Inclination. .., 2. 76 9 40 5. %6 cl AGs
| ae, 20. MA 22 Gs AGES ae

Motion retrograde,

105

Arr. XII. ANALYLIS OF SCIENTIFIC BOOKS.

Sur les Ichthyolites ou Poissons fossiles, Par Monsieur Blainville.
Article extrait du Nouveau Dictionaire d'Histoire Naturelle.
Vol. 28. Paris, 1822.

Tur reputation and the success of Cuvier in that department of
Natural History which respects the animals of a former state of the
globe, and his comparative omission of that branch of these researches
which relates to fishes, seem to have stimulated the author now before
us to the present undertaking. The ambition is laudable, but we fear
that we cannot say the same of the execution. Though this is far
from being the first work which has pretended to treat of fossil fishes,
it is the first which has been exhibited as a complete system of the
present state of knowledge on that subject. That it is both faulty
and imperfect, is sufficiently obvious ; and we are much inclined to
think, that if Cuvier had considered the subject as capable of being
undertaken to any purpose, he would not have left it to his ambitious
imitator,

We fear we must say that this is an instance, among many now too
common, of that desire to shine or glitter in a new science, which is
the disease of the day, and which has rendered geology the victim as
it is the butt of every tyro, who, incapable of dealing with the accurate
sciences, hopes to acquire some notice by evacuating on the unlucky
public, the records of observations and speculations which, like their
authors, have scarcely cracked the shell, and are desirous of flying
before they have learned to walk.

- There are reasons however for our faith in all cases ; and we owe
Monsieur Blainville the politeness of shewing what his claims to
authority on this question are. ‘The work must rather be considered
a compilation from the writings and observations of others, than an
original production ; and therefore the authorities are rather those of
Scheuchzer, Haller, Volta, Faujas de St. Fond, Lametherie, Lamanon,
Cuvier, and others, than those of the writer himself. Thus far,
different measures of confidence will be allotted to them: confidence
regulated, partly by the weight of the several persons quoted, and
partly by the state of know ledge of the periods at which they severally
wrote. Besides, and in aid "at this, Monsieur Blainville has had
access to the collections in the Museum of Paris, and thus has had
the power of comparing, in many cases, the printed descriptions with
the specimens.

~ But somewhat more than all this is required for a just or luminous
compilation on such a subject ; H and here, our author, we are sorry to
say, is entirely deficient. It is one thing, even admitting that could
be done in the present case, to ascertain the comparative anatomy of

106 Analysis of Scientific Books.

the animals in question, and another to assign them truly to their
geological situations. It is not sufficient that every fragment of bone,
whether of land animals or of fishes, should be referred to an indi-
vidual species or genus; but it is most essential that the true geologi-
cal situations in which they occur, should be accurately understood
and accurately described. We do not want to know merely what
animals have existed, but when, where, and how they lived. .Doubt-
less, it is important to know that many animals lived at all in a
former state of the world, which are living in it no longer ; it is im-
portant to know what these were, and how many ; what species and
genera have disappeared. ‘This is a question however, which, ab-
stractedly taken, concerns zoology only. The geologist is anxious
for much more. He desires to know at what period of the globe
they were in existence, in what lands or waters they lived, when they
were buried and preserved, and how. And he desires to know all
this, because he makes use of it as evidence respecting the history of
the globe and its revolutions. Hence, he ascertains, or at least addu~
ces collateral evidence towards ascertaining, the nature, and order,
and places, and comparative times of its revolutions; and thus he
acquires knowledge which, judiciously combined with the history of
the mere rocks themselves and their various phenomena, enable him
to make nearer approximations to a true theory of the earth.

It is indispensable therefore that the comparative anatomist should
in this case be a practical, expert, judicious, and experienced geolo-
gist. He should be as replete with sound logic as he is free of
system; should be as accurate an observer of geological facts as well
stored with observations ; and should be able, from his general know-
. ledge, to exercise a critical and sound judgment on the reports and
observations in zoology as in natural history, of those from whom he
is compelled to borrow what he has not possessed the means of ascer=
taining from personal observation.

We wish we could say that Cuvier, much as we respect his sound-
ness of mind and minute knowledge in comparative anatomy, were
able equally to stand this test in geology. We wish we could say this
in a far minor degree of Monsieur Blainville ; but he is no geologist.
Judging from his book, we are entitled to say that he has as little
knowledge of this important part of his duty as is well possible.
He is no observer, and he cannot be a critic. Hence every thing
from which the geologist ought to have derived assistance, all that
he would have turned to for light, only leaves him in darkness, the
same or worse than before.

Monsieur Blainville copies, without discrimination, from the descrip-
tion of those who wrote before geology had been rescued from its
ancient state of night and chaos; and, unable or unwilling to verify or
rectify the observations of his remote predecessors, leaves every
thing where he found it, or rather, adds to the confusion which per-
vades their remarks.

M. Blainville on Ichthyolites. 107

Such a work could not have been executed as it ought to have
been, either in Paris or in the Paris Museum. It ought not to have
been attempted, but by him at least, whose experience in geology
rendered him competent, from other knowledge, acquired in other
places, to verify the probable truth or detect the fallacy or imperfec=
tion of the reports of places which he was unable to visit. That the
attempt has consequently failed in its most essential part, is but too plain.

We wish that, what we have said, (and we might say much more
did our limits permit,) would impress, not only on our neighbours
but on the geologists of our own country, the necessity of keeping a
steady regard, in their investigations, on the ultimate purposes to
which these ought to tend or be directed. Geology itself, the history
of the globe of the earth, is a difficult, severe, abstruse and laborious
study. It requires much personal labour, much time, much acute-
ness, some reading, much freedom from system and prejudice, and
an earnest desire for truth; with a cautious, rigid, severe, logic, and
trained habits of a close and strict reasoning, which partakes often as
much of moral and metaphysical, as of mathematical thinking and
induction. It is not the collecting of specimens, or the forming of
sections in the closet, and of coloured maps from the imagination, or
from much conjecture and little observation, which constitute geolo-
gy; and, this abstracted, there is little in it to satisfy the craving
desire for ease and amusement united, and for some poor temporary
fame to be acquired by papers in transactions and systems of Scot-
land or Siberia, on which the dilettantes in science live. Hence the
labour is shunned; and the study evaporates in the far easier task of
collecting bones and shells, in marvelling at the crocodile and rhino-
ceros which occupy the place since held by the two kings of Brent-
ford, or at the kyena who proves the hardness of his jaws upon the
bones of Yorkshire rats, and at the nature of A/bum Grecum.

But we must reserve our general criticisms on the present state of
this science for a fairer opportunity, and return to Monsieur Blainville.

We have said that he was no geologist, and that he was incompe-
tent to his subject, because deficient in that most essential part of it.
But we have a serious objection also to make, to the other department
of his work ; to the rigidly zoological or anatomical part of it. All
the world has marvelled, and with some reason, at the ingenuity with
which Cuvicr has contrived to erect new genera and species, and to
produce entire animais which were never yet seen, and never will be,
from fragments of rotten bones; constructing a Megzetherium from a
maxilla, and a Hyena from an os hyoides, With this we have
nothing at present to do; satisfied with the ingenuity of the Zadig of
the day, and, as far as authority can avail, quite as willing to allow
him the dictatorship in this matter as any other person. There is
always a latent delight in surrendering ourselves to the marvellous,

But even to this delight there are bounds ; and when these are ex-
ceeded, we are aptto feel a twinge of the “ incredulus odi.”” Unquese

108 Analysis of Scientific Books.

tionably, the skeleton of a fish may be good evidence for the fish
itself, as far as we may be satisfied without regaling on it, or are
contented with guessing how it might have looked in a drawing, or
skinned, varnished, and stuffed with plaster of Paris. This mode of
assigning a species or a genus, will be still more satisfactory, when
the naturalist has had the means of comparing the preserved skeletons
of former days with those of existing species and genera to a sufhi-
cient extent. But who need be told that there is such a simplicity
and general uniformity in the skeletons of fishes, that the limits to
this mode of investigation are very narrow indeed. They have no
legs nor arms, no scapulee nor knee-pans, no os coccygis nor ster-
.mim, nor phalanges, nor any of those multitudinous and ever varied
parts from which the comparative anatomist derives so much facility
in his researches on quadrupeds. There is something in the number
of the spinal bones, there is something in their forms and propor-
tions; and there is still more in the bones of the fins and in those of
the skull. But all this is little; and while but little evidence can be
derived from fragments, we are particularly determined to distrust
Monsieur Blainville on points which neither he nor any one else
could have ascertained, namely, the erection of new genera and new
species from the contemplation of fragments, and these fragments
often distorted by the effects of pressure and the other causes of
change and injury to which fossil bones are exposed.

When we said that Monsieur Blainville was ignorant of geology,
we might also have said that he does not seem to have formed any
conception of its nature and meaning, and of the relations of his own
subject to it; considering this, as we do, rather a branch of zoology
than of geology properly so called. He speaks as if the strata were
only casual substances which might or might not be studied, but
as being “* often useful.” We would gladly know how they are
not always necessary instead of being often useful, at least in our
view of the subject. If the object is merely to ascertain lost animals,
they are neither necessary nor useful ; whence it is plain that when
M. Blainville speaks thus, he is thinking of geology, not of his fishes,
and thinking too, to little purpose.

When he asserts that the nature of the organic remains offer the
most ‘* unequivocal methods of establishing geology on indisput-
able bases,” he is only saying what others have said before him, but
which is not a bit the more true because it has been often said. In
the first place, we will admit this, and then ask to what extent the
science of geology can be based on the knowledge of organic re=
mains? In many countries they do not exist; in many rocks they
never occurred. ‘They are limited to a small portion of the geogra-
phical globe, and they are confined to a small depth of the geological
one. What would become of the theory and history of the primary
rocks, of the trap rocks, of the volcanic rocks, if their history and
theory depended on their organic remains? The organic remains

M, Blainville on Ichthyolites. 109.

are connected mainly with. the last revolutions of the globe ;—uni-
versally with the later ones, And yet among these later, we must
except the latest of all, which are the whole of the two classes of
rocks produced by fire, the traps and the volcanic rocks. As to all
the rocks which precede coal, with little exception, we should never
obtain any knowledge of their theory, did we depend on the evidence
to be derived from organized bodies. That they prove many things,
is unquestionable; but it would be a defective system of geology
indeed, and we might well despair of attaining any knowledge of that
science, if we had no more knowledge and no wider views than
Monsieur Blainville, and, (we might add,) many more, seem to
possess on this question,

We are equally ready to deny, and to prove it, had we room, that
even the order of the succession and the true theory of those very
strata in which organic remains exist, can be proved by means of
them. This has been a favourite theory to the present day, and it
has a large body of abettors still. But we could prove, by their own
evidence and shewing, that it is unfounded; by quoting their own
catalogues of the strata and their included shells, and by shewing.
that the same genera, and the same species in many cases, occur
through all the series, in positions the most remote. We could even
prove it @ priori from zoological considerations. Were the assertion
true in geology, or in organic mineralogy, (to use a better phrase,)
then it would have been a necessary preliminary that. all climates
should have produced, at different remote times, similar families of
animals; that all these should have followed each other in a certain
unvarying order, and that the same order and kinds should have
existed and succeeded every where in one manner. It would have
been impossible that there should now have been, had the same laws
prevailed formerly as now, oysters at Milton, and muscles at Hastings,
and cockles at Margate, and periwinkles at Dover,

But we have not time for what well deserves a separate discussion ;
and having thus far disputed Monsieur Blainville’s preliminaries,
shall proceed to make a few remarks and extracts from a book which
we might have ¢asily disputed at every page.

As we cannot afford to quote a great deal, we must try to be con~
tent with a few passages, and shall take the following in the first
instance. We insinuated this author’s want of logic; and surely it
was an unjust insinuation, since the arrangement would do justice
even to Jeremy Bentham. There is a Tudesqueness in it which is
quite delightful, and which bespeaks the genius of a German pro-
fessor crazed with the logic of Kant and Burgersdyck, and the reading
of the schools, rather than the cestrus of a lively Parisian skipping
through the dry bones of the Musée. If it is along passage, we
can only say in its defence, as Horace Walpole did after Gray, and
of other passages, that it ** leads to nothing.”

110 Analysis of Scientific Books.

** Sous le rapport de la composition chimique ou anatomique,”
(he is speaking of organic fossils.) J’ai divisé les corps organises
fossiles ; A. en ceux qui n’ont éprouvé aucun changement dans leur
tissu, dans leurs compositions chimique et mineralogique; B. en
ceux qui ont perdu seulement et entierément la matiére animale;
C. ceux qui ont la méme composition chimique moins la matiére
animale, mais qui ont perdu de plus leur structure et leur forme;
D. ceux qui n’ont perdu que la partie organique, mais dont la por-
tion inorganique a pris une disposition toute différente de la Spathifica=
tion E. qui ont éprouvé des changements dans la tissu anatomique
et dans la composition chimique, méme dans I‘acide du sel terreux
qui les fermait ; F. ceux qui n’ayant rien perdu dans la structure
organique. ont été entiérement changés dans la composition chimique;
de la Petrification: G, fossiles qui sans avoir éprouvé de modifica-
tions ont été imprégnés d’une substance metallique ; de U' Impregna-
tion ; H. des corps incrustés ; I. des corps succinisés,”

This reminds us of a modern Act of Parliament: a trap set to
catch all the modifications of possibility, and somewhat more; but
which is still so ill-constructed, that lawyers, rats, and criminals con-
trive to escape it.

A German engrafted on a Parisian, forms a heteroclite-enough
animal; somewhat, we should conceive, like Monsieur Blaiiville’s
own paleobalistums and paleorynchuses. But such is the conse-
quence of going to school at Freyberg. We thought that the Pope
had been dead, for, like his namesake in John Bunyan, his nails had
been pared some time ago; but it seems that his ghost still walks.
The earth, says our author, is divided and subdivided. This is
highly instructive ; and firstly of the second, which are the organi-
ferous strata, and of which the subdivisions are thus stated. We
would have translated this logical and luminous passage for the
benefit of our English readers but we want words. The divisions in
French therefore are, ‘‘ lre. ‘Terrains zootiques les plus antiques, trés
antiques et antiques: 2me. Terrains les plus ancicns, trés anciens, et
anciens: 3me. Terrains modernes, comme d’alluvion, des tourbiéres :
and lastly, 4. Terrains recens ou terrains meubles et couches super-
ficielles.”” We have condensed the quotations, and hope they are the
more intelligible. As to the first or the grand division, it is zootique
and azootique. It is a fine thing to understand Greek and Logic;
and the author’s positive, comparative and superlative, antic and
ancient strata, remind us of the ‘‘ heavy not particularly light,” and
the * intermediate between hard and semi-hard inclining to the soft,”
with the “ scopiformly divergently radiated,” and so forth, which
argue the metaphysical aud delicate profundity in language and
thinking, which distinguishes another of the luminaries of this science.

But we have said enough of this author’s general views, and must
give a few specimens of his details. Of these, after the geological

M. Blainville on Ichthyolttes. 111

confusion which we have already sufficiently noticed, the leading
character is the ambitious desire of creating new species and genera ;
apparently, with the design of rivaling Cuvier in his own peculiar
walk, and for the sake of displaying his profound knowledge of
Greek. As this language constitutes rather a novel science in France,
we must excuse Monsieur Blainville for his wish to prove that he is
actually the possessor of a Greek Lexicon.

Whether the strata of Glaris are to be considered as most antique
or very antique, or antique, or whether they are most ancient or
very ancient, or ancient, to which of these two sets, in short, of
positive, comparative, and superlative entities they belong, Monsieur
Blainville has not told us, and we cannot guess, But we must try if
we can Conjecture to what rank they belong in the vulgar language.
We sincerely wish that geologists would use the same words as other
people, to express such ideas as they happen to possess, If matters
proceed much further in this way, what with German nomenclatures
and French nomenclatures, books on geology will become as intelli-
gible as the treatises for digesting sol with luna under the red dragon
per ‘‘ pemset remsen ame muc senvu saltrafi,”

Scheuchzer, as well as Ebel and many others, have examined this
place, and many collections have been formed fromit. It is situated
to the south-east of Glaris, in a small valley, at a distance of about
five miles, in « part of the mountains called the Plattenberg. The
including rock is a blackish fissile schist, containing some mica, and
interstratified with thin lamin of limestone. It is, as he says, the
Grauwacké schiefer of the Germans, and, what is worse, the Phyllade
pailletée of Brongniart, as if one hard name was not enough. The
specimens here are very imperfect, being only the impressions of the
fragments of skeletons; one side of which has formed a sort of bas-
relief in the schist, while the other is very ill-defined.

_ Now Haller, a name not to be spoken of lightly, even by Monsieur
Blainville, mentions the impressions of ferns as being found in the
same places; but this he thinks improbable, because Brongniart
found none in the collections which he examined, and chooses to call
it a transition rock. Here the question of the geological nature of
this deposit becomes inost important. Our author, making up his
mind that it is a marine formation, determines that all his specimens
are sea-fishes, We have abundance of respect for Brongniart, but
have also good reasons for not giving implicit credence to his geolo-
gical opinions. Cuvier thinks it is marine, because it contains the
remains of a tortoise, and because that tortoise must have ‘been a
marine one. We should be very glad to know whence this necessity
arises: there was formerly the same compulsion on all the Lacerte,
the crocodiles, to helong to fresh-water ; but, unluckily, Lieutenant
Kotzebue finds that there are sea crocodiles in the Pellew islands.
Here then we have a contest of evidence: the ferns which Haller
saw, against the tortoise that must have lived in the sea; and, further,

112 Analysis of Scientific Books.

the opinion of Andrza, who says that it is a fresh-water formation,
against that of Brongniart. We do not intend to decide between dis-
agreeing doctors, but it is a justice to our readers, if they are readers
also of Monsicur Blainville’s Ichthyolithology, to dissect these para=
graphs for their use.

Eight species of fish are described as being found here. Of two
of these, Monsieur Blainville makes new genera, by the names of
Anenchelum and Palzeorhynchum ; the others are supposed to belong
to Clupea and Zeus. The first of these was formerly imagined to be
aneel; and although that opinion was probably wrong, we cannot
see, how, from the miserable evidence which the fragments are ad-
mitted to afford, itis possible to make a new genus for it. But this
naturalist finds less difficulty in constructing a genus out of a fin or
a tail, than Linnzeus did with the whole living races before him :
according to the well-known adage, ‘‘ Qui ad pauca respiciunt de
facili judicant.” Here is the way, for example, in which Paleeorhyn-
chum (old Snout, for the benefit of the unlearned) is made.
“ Quoique cet Ichthyolite, dont nous n’avons vu que la figure de la
partie anterieure, dans l’Herbarium diluvianum tab. 9, fig. 6, nous
soit trop insuffisament connu pour appuyer notre opinion, il ne nous
paroit nullement probable que ce soit notre aiguille ; (sox bellone,)
ainsi donc, jusqu’ 4 des circonstances plus favorables, nous propo-
serons de la designer provisoirement sous le nom de Palzorhynque
de Glaris.””’ We shall really be glad to know how such trifling as
this can conduce to the study of ichthyology, or geology, or any
other Ology in the whole circle of the sciences,

Scheuchzer takes another of these fishes for a bleak ; not an un=
likely conclusion, if this same deposit contains ferns; but our author
chooses to make it a new clupea. A fourth was esteemed a pike,
and this also he makes a clupea; which judgment being deduced,
not from a specimen, but from a figure by Knorr, it is very satisfac-~
tory to be informed that it is uncertain whether that appertains to the
rock of Glaris or not. On such principles as this, we are likely soon
to abound in Ichthyolitologists and Ichthyolitologies. There is a
third clupea, with a new title also; all of which is matter of course,
since it was predetermined that this was a marine formation.

Next comes the genus Zeus, of which he finds three new species.
To show how satisfactorily these points are settled, in the first place,
the first species is determined to belong to Glaris, not because it was-
found there, but because it lies ina similar slate: as if similar rocks
of all kinds were not found all over the world. This may very well
be a marine fish, if he pleases ; but how does it follow that it has any
thing to do with Glaris, or that it proves this to be a marine deposit ?
As to its own characters, it has ‘* des rapports avec le Zeus, ou genres
voisins ; mais c’est ce qu’on ne peut assurer, parce que la téte toute
entiere manque.” Then “ toujours est il constant que c’est un poisson
marin.” Very possible. And so for the others.

M. Blainville on Ichthyolites, 113

The fossil fish of what is called the metalliferous slate, are well
known to be abundant, in numbers at least, if not in kinds; and they
occur in many different places. The most noted of these are the
Palatinate, the Voigt, and Thuringia; and they have often been de-
scribed by different authors, such as Kruger, Friesleben, and others.
It is somewhat remarkable with respect to these specimens, that they
are almost always much distorted and injured ; not even being com=
pressed and preserved laterally, as is the most usual case in the fossil
fishes, It is equally so, and important at the same time in investi-
gating the species, that the impressions are those of the skin and sub-
stance of the animal, not of the skeletons.

With respect to the nature of this deposit, we have no objection to
be convinced that it is a marine one, if it appears that any one of the
fish is marine, or that any one sea-shell is contained in it. It may
very probably be so, although no such evidence is produced. But if
we are willing to believe quietly and without any evidence at all, we
do not choose to be obliged to believe by that which is not evidence ;
and this, not on account of any concern we feel about the bitumino-
metalliferous schist of Mansfeld, but because of the very testimony
itself. We have a mortal aversion to corrupt evidence in all its
modes, and do not choose to pass any attempts to introduce any more.
of it into geology, where there is already an abundance.

These strata are determined to be marine because they lie beneath
calcareous rocks containing ‘‘ ancient” (or modern) marine shells,
such as belemnites, entrochites, and ammonites, of the same kind as
those that belong to the limestones of the Apennines and Alps, toge=
ther with gypsum accompanied by sea-salt, gypsum without sea-salt,
sandstone, and so forth. Now these strata are the exact counterparts
of the red marl and lime of England; particularly where they are
somewhat intermixed. We have no objection, either to their marine
origin, or to their antiquity, if that will give Monsieur Blainville any
satisfaction ; but neither of these will prove that the strata below them
are of marine origin also. Our own coal strata are situated in this
very position; and no one now, it is hoped, since the theories of
Dr. Hutton and of Kirwan on this subject are forgotten, will imagine
that a series which contains terrestrial vegetables in abundance, and
which never was known fairly to include a seashell, is of marine
origin. ‘Thus much for what is possible respecting this deposit of
ichthyolites.

Monsieur Blainville has made twelve species and three new genera
out of this collection. The new are palzoniscum, paleothrissum
and stromatcus : the old ones clupea and esox. In general we may
remark on these determinations, that they are more free from objec
tions than some of the preceding ; as the author had access, in many
instances at least, to more perfect specimens. How far, however, his
arrangements are justified, we cannot pretend to decide. We may

Vou. XVII.

114 Analysis of Seientifie Books.

nevertheless remark, that he has here attempted to give generic
characters, which, in some other cases, he has oddly enough seemed
to have thought unnecessary. Surely if a genus or a name is to be
erected for an ichthyolite, or any other kind of lite, the purpose is, if
there be any purpose at all, to allow others to refer to it, and to
arrange their discoveries under the appropriate division. If this is not
to be, if there is only to be a paleeo—something, without characters,
we do not see what natural history, ichthyology, or geology is to
profit by such a coinage of crabbed words; while we do see that,
on the same principle, we may shortly have as many genera as there
are specimens; a proceeding likely to be attended with no con-
venience that we know of to compensate for the vexation of such a
catalogue, except that of inducing gentlemen to turn the leaves of the
long-forgotten Lexicon ; that unlucky book, thumbed in the Anglo
Greek division by every projector who wants to dazzle our under-
standings with a Diatalaiporou, a Therapolegia, an Anthropomono-
troche, « or an Apolepsia alexicacon.

Of these new genera we shall give the characters of that in which
our author has been most successful and appears most justified, asa
compensation for some of the others which we have noticed.
“« Paleothrissum.” “ Ila pour caractere essentiel: d’etre abdominal,
malacopterygien, de n’avoir qu’une scule nageoire superieure située
devant \’anale, entre les pelviennes et elle, et surtout d’avoir la queue
bifurquée, et le lobe supéricur ordinairement beaucoup plus long que
Yinferiecur, et couvert d’ecailles dans toute sa moitié supérieure.”
There are four species of this: but Kruger thinks that one of them is
a pike; it is doubtful if two of the others are not the same, though
each one has its own name; and, what is worse, the geological rela-
‘tions of the rock in which these are found is doubtful.

That one which follows is called stromateus ; but, as is most usual,
has no generic characters assigned. How species are to be established
before a genus is determined, rather surpasses our comprehension ;
nevertheless there are three, with the names major, gibbosus, and
hexagonus, (surely the love of arrangement is a terrible disease,) and
two more without names, the genera of which, are, however, left in
doubt, We shall extract a few words from these descriptions that
naturalists may see what marks they may have to deal with when
they take to the investigation of ichthyolites,

No. 11.—On trouve encore & Eisleben une autre en d’ichthyo-
lite, mais qui jamais, ou fort rarement est entiére: d’aprés la grandeur
de sa téte, on suppose quelle pouvoit avoir prés de trois pieds: sa
peau etoit, dit on, comme chagrinée. D’aprés cette indication, je
- supposerois volontiers que les ‘oryctographes indiquent par la un
poisson fossile, dont j’ai vu l’empreinte d’une partie de la peau dans
Ja collection de Monsieur Brongniart. On y peut reconnoitre a ce
qwil m’a semblé, une assez erande nageoire dorsale; mais ce me

v

M. Blainville on Ichthyolites. U6

cette peau offre de remarquable, c’est d’etre entitrement, récouverts *
despéces de petites écailles, comme trifurquées a leur pointe, et qui
semblent formées par deux chevrons disposes en sens inverse.

Je n’essaicrai aucune conjecture sur le genre de poisson a laquelle
cette peau a appartenu; mais je ferai l’observation que l’espéce
d’ecusson qu’ on voit souvent a la racine des nagecires, dans les fossiles
que j’ai designés sous le nom de Palzothissum, ressemble beaucoup
a ces sortes d’ecailles.”

We have no objection to this manner of contemplating the subject.
It is proper that specimens, be they never so imperfect, should be
preserved, and figured, and described ; because by the comparison of
fragments at some period, a species or a genus may really be deter-
mined: it is not often that our author is so moderate: and, to con-
tinue, we shall give his equally prudent remarks on No, 12.

‘‘ Enfin, on cite encore, comme d’Eisieben, quelques restes, dont la
peau est lisse comme celles des anguilles, Je crois avoir vu, dans la
collection de Monsieur Brongniart, l’empreinte d’une portion de peau,
qui a du appartenir a cette espéce. Le peu que j’en ai observe, et qui
me paroit provenir des environs de |’anus, indique évidemment un
poisson anguilliforme: toute la partie superieure offre des stries nom-=
breuses verticales ; et l’autre moitié ou inferieure, est couverte de trés
petites ecailles, fort luisantes, serrées, ovales, qu’on ne voit aisément
qu’a la loupe,” 7
_ So much for the fishes of this deposit. But we must add that
Leibnitz thought that he had found in it a mullet, a perch, anda bleak ;

ruger also describes a pike; so that it may yet be a doubt whether
these are marine or fresh water fishes; because, even if we were to
grant Mons. Blainville all his new genera and species, it does not at
all follow that they are marine ones. A word or two on this part of
the subject will not be misplaced ; as the determinations of our mo-
dern zoo-geolists on many parts of their investigations are very
mainly and materially guided by certain notions which they
have formed respecting the distinctive character of marine and
fresh water species.

Let us put the very simple case that the salmon, the sea-trout, the
sturgeon, or the sterlet, were found in a fossil state, we should be very
glad to know how it is to be determined whether these are marine or
fresh water fishes; they are both the one and the other, —

_ But we will carry the matter a little further and say, that there are
no marks in the anatomy or natural characters of a fish by which its
habitation can be known @ priori. It is a pure matter of experience
now; and there is no experience about these ancient animals. For
any thing to the contrary that we can ever hope to prove from natural
characters, these ichthyolites may have been the inhabitants of fresh
waters, or of the salt ocean, or of great inland lakes, such as are the
lakes of Switzerland now, or such as the basin of Paris assuredly was
long ago, In the same way, oe gn have attempted ta decide
€
ye

116 Analysis of Scientific Books.

upon fossil shells, inhabitants of the sea and similar objects, the
natives of fresh water. That also in matter of experience, and of that
only ; and of the past, the so long past, there can be none, There is
no character by which these can be recognised : it is not to be found
in their tenderness, or the reverse, as once imagined. Itis not found
in generic characters, because there are species in one genus, some of
which are inhabitants of the sea, and some of lakes and rivers, just as
much as there is a sea eel anda rivereel; a Murena anguilla and a
Mureena conger. Indeed with respect to the shell fishes, Mons.
Freminville has lately shown that sea and fresh water kinds all live
together in the same place. But we need not pursue this point fur-
ther, and shall return with Mons. Blainville to his next geolosical
division, the ichthyolites of what he calls the ** Calcaire compacte.”

As his method of division is geological, we think it would have been
as wellif he had satisfied his readers first of the propriety of his geo-
logical arrangements. ‘ Calcaire compacte” may mean a great deal.
The geological characters of the former strata, were merely doubtful:
those of the present cannot possibly be right. The first locality, for
example, is Granmont, situated at four leagues frem Beaune in Bur-
gundy ; and the rock is the “ calcaire ancienne, contenant des gryphites
et des belemnites,” which is “ situé audessus du gres rouge, et que
V’on croit presque aussi ancien que celui du Jura.” The next is
Italy, where, without any other evidence than the colour and look
of the detached stone, one is decided to belong to the Apennine lime-
stone; we have no hesitation in admitting that some of them actually
do so.

If “ calcaire compacte” is to comprise such rocks as these, and if
it is thus to be considered as one geological formation, we ought to
have been furnished with more accurate geological information res-
pecting them, that we might have judged of the propriety of this
arrangement. If there is any object in dividing the ichthyolites accord-
ing to the strata in which they are found, it is for the purpose of
inquiring into the somewhat interesting question of their relative
antiquity. This is what Cuvier has properly done with respect to the
Paris district ; and Mons. Blainville, while he was about it, might as
‘well have imitated him in that too, had he not been solely occupied on
fish bones, thinking, doubtless, ‘*in tenui labor at non tenuis gloria.”
But we must inquire about the Ichthyolites themselves,

There is first a new Elops, the macropterus, from Granmont,
which may or may not be an Elops; and then there is another
called incognitus, imbedded in a ‘pierre calcaire dure, assez com-
pacte, grise, et formant une sorte de noyau dont j’ignore la loealité et
le gissement.” ‘This is not a very accurate geological arrangement at
any rate. The fish of Italy are left pretty nearly as they were found,
but our author takes, or makes, an opportunity of cutting off Brieslak’s
head with a golden hatchet. We cannot pardon Brieslak any more
than M, Blainville, because he has a troublesome way of thinking for

M. Blainville on Ichthyolites. 117

himself, and of professing that he does not understand the mystical
language in which the French geognosts shroud their oracles :—
‘¢ Brieslak fait l’observation, qui nia été confirmée par Mons. Menard
de la Groye, que on ne trouve dans cette localité qu’ une seule espece
de poisson fossile, que l’on regardé 4 Naples, et méme parmi les savans,
comme analogue du sparus quatracinus, appelé dans cette ville, spara-
glioni. | Comme l’observateur dont je viens de parler, en homme qui
sait agir dans ces sortes de recherches, a raporté 4 la fois ce fossile et
Panalogue présumé, j'ai pu, grace asa complaisance, m’assurer que ce
rapprochement est tout-a-fait erroné. En effet, le poisson fossile me
paroit appartenir au genre Zee, ou a l'une des subdivisions qu’ y a
introduites Mons. La Cépede; aussi la hauteur de son corps surpasse
Ja moitié de sa longueur, tandis que, dans le sparus quatracinus, elle
est environ le tiers.” So much for Breislak and his sparaglioni.

The next geological formation is the chalk, which includes Brussels,
Maestricht, Paris, and Perigueux. The first ichthyolite mentioned
affords a good specimen of ichthyolitologistical reasoning. | M. Bur-
tin begins by giving ‘‘des figures assez bonnes.’”’ —M. Blainville “ n’
en apas vu lui meme,” therefore it is, first ‘* Zeus auratus?” “ que je
croirois volontiers du genre Pleuronecte, et peut etre la Barbue, ou
mieux encore le poisson de St. Pierre.” John Dory after all. But
then M. Burtin, who has drawn this very “‘ figure assez bonne,” sees
fins, and ears, and sculls, and jaws, and teeth, and orbits, and clavicles,
and scapula, and vertebree; while M. Blainville sees ‘‘ rien de tout
cela dans la figure.” And then M. Burtin “ veut je ne sais trop pour=
quoi,” that this isa Chtodon. But enough of the chalk formation.
There is more of the same kind of useful information respecting the
“ formation du Calcaire grossier, infériéur au gypse.” Cuvier seems
to have been too wise to attempt it, and we shall spare our readers
the sparus that may be a labrus. |
_ Then succeeds an account of the fishes of Pappenheim, but we
cannot afford to enter on the details in the same manner. The only
remark we shall indulge ourselves in making, is, that in describing
five species in the genus clupea, which seems a particular favourite
with our author, he has borrowed from Knorr’s figures, instead of
consulting the specimens themselves. Thus the probabilities in favour
of truth are, that, in the first place, Knorr himself is correct; next,
that his painter has figured impressions of fish bones so accurately,
when the value of the subject was not understood, as to enable M.
Blainville to determine different species of clupea, and the genus itself
from them; and, lastly, that the author has no favourite system res-
pecting his genera, the contrary of which is evinced in every page of
his work. ‘The proof of this latter is, that all the figures which do
not chance to suit the fashion of the moment, are pronounced bad;
and that when they happen to suitit, they serve the purpose, with
him, of demonstrating what such figures are totally incapable of
proving,

118 Analysis of Scientific Books.

His rage for maintaining his system at all hazards, is equally proved
by another decision in this very case of Pappenheim.’ He finds a
figure in Knorr, but without a locality assigned; yet he determines
that it must belong to this spot, because it seems to lie in a similar
stone. Weshould be glad to know how any figure can represent a
stone, so as to render its locality certain, or even probable, We are
sure that no figure of Knorv’s is capable of distinguishing any one
stone from another, far less the slates of Pappenhcim from the’ slates
of Shropshire or America. If thus M. Blainville’s geology is stndied
and ascertained, we cannot have too little of it. As to the general
geology of this celebrated spot, it is derived here from the description
of Reuss and Humboldt; and a worse piece of geological observation
and reasoning, we will venture to say, was never printed. ‘That it is
a fresh water formation appears almost certain, so far from being
what is represented; and that the observers have confounded and
misrepresented the relative positions of the fresh water and marine
strata, is equally so, though we cannot here enter into the reasons for
this opinion.

As to the ichthyology, it is ofa piece with the geology, which is
Jess pardonable, since the author’s claims in this department are more
decided. The figure is that of a sturgeon, and yet he chooses to decide
that it is an unknown pike, to which he gives the name of Esox acu-
tirostris. Stromateeus and Pecilia, from the same place, are deter-
mined on grounds as slender. The specific name of the latter is
Dubia; and if we were inclined to make a very low jest, we should
say that it was applicable to three fourths of the whole collection.

Mons. Blainville has entered into considerable length on the subject
of the celebrated fishes of Monte Bolea, and we are glad to say that in
this part of his treatise he has been of real service to the cause in hand,
It is, in truth, the most valuable, and we had almost said the only
valuable part of his book. With the double advantage of the splendid
work, published at Verona under Volta’s direction, and of the ecol-
lection itself procured, (plundered, as ‘Ttaly asserts,) from Count Gaz-
zola, he has been enabled to rectify the more glaring errors of the
Italian naturalists, and to give somewhat like a rational list of the
specimens. Out of Volta’s forty-four genera, including a hundred and
five species, he has admitted only ninety-three species, and it is
quite plain that they would allow of still farther purification.

This subject, however, is so extensive that we dare not enter it.
We have no room for a criticism on genera and species, which in-
deed could not be rendered intelligible without the figures. But we
are bound to say, on the geological question, that the Italian theory
which collects these fishes from all parts of the world, is purely gra-
tuitous; and thus while it is geologically impossible and groundless,
it is contradicted icthyologically by the specimens themselves, which
are now, in part, and in former times have probably all been, natives
and residents of that sea which now washes the land in which their

M. Blainville on Ichthyolites. 119

remains are preserved. It would be easy to state a rational theory
of this formation, and its relations to parallel phenomena in many
parts of the world: but they are in a good measure superseded by
the present more rational views of the history of the supramarine or
ganiferous strata.

We said before, that it was incumbent on an author, professing to
give a general treatise on ichthyolites, or of any other branch of
this .science, to make himself acquainted with the facts at least
which are accessible, or to acquire such knowledge as would enable
him to profit by the observations of others. The defect of our author
in these respects is peculiarly sensible in what follows, where he has
copied careless observations in a careless manner, and rendered the
confusion more offensive and troublesome by the systematical and
decided form in which he has placed it. Mount Lebanon, Cerigo,
Antibes, and many other localities are discussed in this slovenly man~=
ner, from Faujas de St. Fond, and others; and where we ought to
have certainty we have only useless guessing.

We consider that an author who thus professes to write a syste-
matical work, is bound to make it really systematical, as far as that is
possible. Icis a different thing to write single essays, or to describe
those separate localities and partial facts from which geology ulti-
mately derives assistance towards its general views. Hence our
author is equally deserving of censure, that when he quotes Sicily,
Malta, Iceland, and other well known countries, where fossil fishes
have been found, he is scarcely ever at the trouble of ascertaining
what has already been written about them, or of trying to extract
something like truth from a balance of testimonies. As a specimen of
this unpardonable carelessness, he quotes Antibes as a locality, and
then doubts whether itis not Antigua. Nor could any thing but the
same ambition to make a book and a system, which has led him to
give genera without descriptions and species, under such imaginary and
nominal genera, have tempted him to muster in his arrangement the
fossil fishes of China, of which he knows nothing. On those of England
he is equally unsuccessful; whereas he might have found something
to his purpose, had he taken the trouble to seek for it.

We have already shown our suspicions that many of Mons. Blain-
ville’s marine formations, and marine ichthyolites, are really fresh
water examples ; but we have a detail in the latter part of his essay of
those which are indisputably such, and which he chooses to call Po-
tamiens, “‘ apparemment,” because Tora is a river, and that these
strata have been produced in lakes.

We may pass over the Italian examples, as unsatisfactory: those
of France are better known, and are here better described. ‘The
deposit of Aix is well known to consist of five marked beds, reaching
toa depth of near sixty feet, consisting of marl, limestone, bitumi-
nous marl slate, and gypsum. ‘The fishes which it contains are one
species in the genus perca, acyprinus, and the mugil cephalus or

120 Analysis of Scientific Books.

grey mullet. Thislatter is a sea fish, and an inhabitant of the Medi-
terranean ; though, as we formerly remarked, it can live in fresh water ;
and since this is a decided fresh water formation, here is a remarkable
fact in proof of what we have already advanced on the uncertainty
which attends this subject, and which, if Mons. Blainville had not
been so strenuous a theorist, might have led him to be more cautious
in many of his decisions on this subject.

The basin of Paris has been so thoroughly described by Cuvier and
Brongniart, that little has been left for our author to do; and that des-
cription is also known to every one sufficiently, to render it unneces=
sary for us to enter into any details respecting it. These specimens are
not numerous, and they are generally very imperfect and ill preserved.
As our geological readers must know, they have been described by
Lamanon, Faujas de St. Fond, and de la Metherie, as well as by
Cuvier. The species are limited to seven, and they are all so ill de-
fined that no very satisfactory conjecture respecting them has yet been
made. We shall not quote what has been said, as it is of no mo-
ment in the present review of Mons, Blainville.

Yet we must be indulged in one remark on Cuvier himself in this
case; professing, at the same time, that respect for his attainments
which it is almost superfluous to profess. When the fishes of Veste-
nu nuova were first described, it was the fashion to suppose that the
world had been turned upside down, and inside out, and if there were
two ways of explaining a fact, itseemed to be the fashion and the am-
bition to reject the easiest and most natural solution, for the sake of
adopting what was marvellous, incredible, or impossible. This has
indeed been one of the leading diseases of /geology and geologists.—
Because it was impossible that obsidian and pumice could be formed
by water, they were to be aqueous productions: because the identity
of volcanic rocks and trap rocks was so absolute that we could
almost suppose we had seen the latter formed by the same class of
fires which produced the former, it was resolved that they were gene-
vated from water. Thus, at Vestenu nuova, because there was no
difficulty whatever that the crowd of fishes which inhabit, or inhabited,
the Mediterranean should have been elevated from the bottom of the
sea, entangled in its mud, and indurated in rock, just as they have
been before our very eyes in Iceland, it became necessary to collect
them from the four quarters of the globe. The simple solution was
not marvellous enough, and the dreams of Volta and his party have
been triumphantly repeated and re-echoed, in our own clearer day,
by those who prefer doubt and difficulty, to conviction and facility,
and would rather that truth should not be attained than attain it by
the easy road which all may apprehend.

Of this, we fear, we must accuse Cuvier himself in the case of
Pacilia vivipara, (as he chooses to suppose it,) of the Paris basin, a fish
figured by Bloch, and a native of Surinam, For what possible pur-
pose should we resort to Surinam for a fish for this situation? The

M. Blainville on Ichthyolites. 121

theory is as purposeless as the voyage of the living fish itself to th
Seine would be at this day, unless his object were to attract the
praises, in a Bechamel sauce, of the Gastronomes who sit in judgment
at the tables of Beauvilliers. The very theory of the Paris basin, to
speak seriously, renders this supposition nearly as impossible as it is
unreasonable, and it would-surely be a more rational conclusion that
the fish in question was either a lost native of the Parisian seas, or that
the imperfection of the specimen was the cause of a resemblance far
too slight and doubtful to give the slightest justification to such a
useless and violent supposition.

We are fully aware at the same time of the argument in favour of
such a view, which may be founded on the existence of vegetables
with intertropical characters or analogies, in the same climates in
which the Paris basin is situated, But this whole question, as far as
it relates to change of climate, or an alteration in the position of the
earth’s axis, is very obscure, or more than obscure: and were it not
so, it must be remembered that the coal strata belong to a far remote
period of the earth, antecedent by many and by millenarian revolu-
tions to the basin and deposit in question. We have no right to argue
thus, and it is only to perpetuate the vice from which geology has
already suffered so severely.

But it is time for us to bring this article to a close, and to take our
leave of Mons. Blainville and his ichthyolites. We wish that we could
have spoken more favourably of a performance which contains far
more of conjecture and trifling than of useful and solid information,
and which is not calculated to add much to our stock of knowledge.
We do not undervalue this particular pursuit; on the contrary, we
think it highly desirable that every organic fragment of a former world,
in every department, should be collected, studied, and described: but
geology, geology itself, the history of the structure and revolutions of
the earth, has also its claims; and such collections and systems more
than double their value when they are caused to bear and throw
light on this important subject. This is what Mons. Blainville has yet
tolearn, We still hope and expect that he will look at his subjectin
this view; that he willturn from the poor ambition of shining in a
catalogue of new and useless names, to that of improving the sciences
which he has undertaken; and that, substituting study for guessing,
and close investigation and careful reasoning for compilation and ca-
talogue, he will appear before us again, at some future day, a new
man, to receive the praise which we shall give with far more pleasure
than we have passed the censure.

122 Analysis of Scientific Books.

Il. The Philosophical Transactions of the Royal Society of
London, for the year 1823, Parr. Il. -

1, On a New Phenomenon of Electro-Magnetism. By Sir Hum-
phry Davy, Bart. Pres. R.S.

This is a contribution of a curious fact to the new and interesting
science of electro-magnetism, and it is by such contributions
alone that this infant science can, at present, be expected to make
any progress to maturity. Sir H. Davy found, that when two wires
were placed in a basin of mercury, perpendicular to the surface,
and in the voltaic circuit of a buttery with large plates, and the
pole of a powerful magnet held either above or below the wires,
the mercury immediately began to revolve round the wire as an
axis, according to the circumstances of electro-magnetic rotation,
discovered by Mr. Faraday. Masses of mercury, of several inches
in diameter, were set in motion, and made to revolve in this man-
ner whenever the pole of the magnet was held near the perpendi-
cular of the wire; but when the pole was held above the mercury,
between the two wires, the circular motion ceased, and currents
took place in the mercury in opposite directions, one to the right
and the other to the left of the magnet. Other circumstances led
to the belief that the passage of the electricity produced motions
independent of the action of the magnet, and that the appearances
“were owing to a composition of forces.

The form of the last experiment was inverted, by passing two
copper wires through two holes, three inches apart, in the bottom
of a glass basin; the basin was then filled with mercury, which
stood about the tenth of an inch above the wire. Upon making a
communication through this arrangement, with a powerful voltaic
circuit, the mercury was immediately seen in violent agitation;
its surface became elevated into a small cone above each of the
wires; waves flowed off in all directions from these cones, and
the only point of rest was apparently where they met in the centre
of the mercury, between the two wires. On holding the pole of a
powerful magnet at a considerable distance above one of the cones,
its apex was diminished and its base extended. Ata smaller dis-
tance, the surface of the mercury became plane, and rotation
slowly began round the wire. As the magnet approached, the
rotation became more rapid; and when it was about half an inch
above the mercury, a great depression of it was observed above the
wire, and a vortex which reached almost to the surface of the wire.

The President thinks that these phenomena are not produced by
any changes of temperature, or by common electrical repulsion,
and concludes that they are of 2 novel kind.

Philosophical Transactions. 123

2. On Fluid Chlorine. By M. Faraday, Chemical Assistant in the
Royal Institution.

[Communicated by Sir H. Davy, Bart., Pres. R.S.]

This paper describes Mr. Faraday’s first step in the important
series of experiments, which led to the condensation of the gases.
He prepared some dry hydrate of chlorine, at a low temperature,
and introduced it into a glass tube, which was hermetically closed.
Being placed in water at 100, the substance fused, the tube be-
came filled with a bright yellow atmosphere, and on examination
was found to contain two fluid substances: the one was of a faint
yellow colour, and the other a heavy bright yellow fiuid, lying at
the bottom of the former, without any apparant tendency to mix
with it. This fluid was easily distilled in a bent tube, and sepa-
rated from the former. When the whole was allowed to cool,
neither of the fluids solidified at a temperature above 34°, and the
tal portion not even at 0°. When the two were mixed together,

ey gradually combined at temperatures below 60°, and formed
the same substance as that at first introduced. If, when the fluids
were separated, the tube was cut in the middle, the parts flew
asunder with an explosion, the whole of the yellow portion dis-
appeared, and there was a powerful atmosphere of chlorine pro-
duced. The pale portion remained, and proved to be a weak
solution of chlorine in water.
* The result of this experiment was confirmed by condensing per-
fectly dry chlorine by a syringe, and then exposing it to a low
temperature; it was thus readily made to assume the liquid form.
~ Fluid chlorine appears very limpid and fluid, and is excessively
volatile at common pressure. Upon cooling a portion to 0° and
then opening the tube, a part immediately fiew off, leaving the rest
so cooled by evaporation as to remain a fluid under the atmosphe-
rie pressure. Mr. Faraday thinks that the temperature could not
have been above — 40° in this case.

He calculates the specific gravity of fluid chlorine at 1:33.

| In a note to this paper, the President of the Royal Society shews
that these results will evidently lead to other researches of the
same kind, and mentions, that by sealing muriate of ammonia and
sulphuric acid in a glass tube, and causing them to act upon each
other, he had procured liquid muriatic acid.

3, On the Motions of the Eye, in Illustration of the Uses of the
Muscles and Nerves of the Orbit. By Charles Bell, Esq.

{Communicated by Sir H. Davy, Bart., P.R.S.]

This is a highly interesting paper, and, together with the second
part, inserted in another part of the volume, is calculated to ex-

124 Analysis of Scientific Books.

plain many ill-understood points of the mechanism and functions’
of the eye, and to renew our wonder at the properties of the organ
itself, and the frame-work and apparatus by which it is suspended,
moved, and protected. Mr. Bell concludes from his researches,
that the high endowments which belong to this wonderful struc-
ture depend not exclusively, as is generally conceived, upon the
ball and optic nerve, but upon its exterior apparatus also. It is
to the muscles, and to the conclusions, we are enabled to draw
from the consciousness of muscular effort, that we owe that geo-
metrical sense by which we become acquainted with the form and
magnitude and distance of objects. It is impossible to do justice
to Mr. Bell’s views in the short space to which we are obliged to
confine ourselves in these abstracts: a careful perusal of the whole
paper is absolutely necessary to those who would wish thoroughly
to understand the investigation, and will amply repay even the
more general reader. The author has shewn, by the most satis-
factory illustrations, that we must distinguish the motions of the
eye according to their objects or uses, whether for the direct
purpose of vision, or for the preservation of the organ; that the
eye undergoes a revolving motion not hitherto noticed; that it is
subject to a state of rest and activity; and that the different con-
ditions of the retina are accompanied by appropriate conditions of
the surrounding muscles; that these muscles are to be distin-
guished into two natural classes; and that in sleep, faintness, and
insensibility the eye-ball is given up to the one, and in watchful-
ness and the full exercise of the organ, it is given up to the in-
fluence of the other class of muscles; and, finally, that the con-
sideration of these natural conditions of the eye explains its
changes as symptomatic of disease, or as expressive of passion.

4, An Account of an Apparatus on a peculiar Construction for per-
Jjorming Electro-Mugnetic Experiments. By W.H. Pepys, Esq.,
F.R.S.

5. On the Condensation of several Gases into Liquids. By M.
Faraday, Chemical Assistant in the Royal Institution,

[Communicated by Sir H. Davy, Bart., P.R.S.]

In this paper, Mr. Faraday follows up the train of investigation
which the condensation of chlorine, by its own elastic power, so
obviously opened.. Mercury and sulphuric acid were sealed up in
a bent tube, and being brought to one end, heat was applied,
whilst the other end was preserved cool by wet paper. The sul-
phurous acid, which was generated, passed to the cold end, and
was condensed i into a liquid. The properties of liquid sulphurous
acid are as follow:—It is limpid’ and colourless; its refractive

Philosophical Transactions. 125

power about equal to that of water; it does not congeal at a tem-
perature of 0°; its specific gravity is nearly 1-42, and it exerts a
pressure of about two atmospheres at 45°.

Sulphuretted hydrogen was generated and condensed in.an ana-
logous way, from muriatic acid and sulphuret of iron. It was
colourless, limpid, and excessively fluid. It was not rendered
more adhesive by a temperature of 0°; its refractive power ap-
peared to be rather greater than that of water, and the pressure of
its atmosphere at 50, was equal to about’ 17 atmospheres. Its
specific gravity about 0:9.

Carbonic acid was also condensed, but it required great pre-
cautions to effect the condensation with safety. It is a limpid,
colourless body, extremely fluid, and floated, as did all the pre-
ceeding liquids, upon the contents of the tube, without mixing.
It distils readily at the difference of temperature between 32° and
0°; its refractive power much less than that of water, and its va-
pour exerts a pressure of 36 atmospheres at a temperature of 32°.
In endeavouring to open the tubes which contained it at one end,
Mr. Faraday states, that they uniformly burst with powerful
explosions.

Fluid enchlorine was also obtained, and proved to be a transpa~=
rent substance, of a deep yellow colour, and highly elastic powers.

Liquid nitrous oxide 1s limpid and colourless. It boils rapidly
by the difference of temperature between 50 and 0°, and does not
solidify at—10. Its refractive power is less than that of any known
fluid, and the pressure of its vapour is equal to above fifty atmo-
spheres at 45°.

Liquid cyanogen is limpid, colourless, and very fluid, and does
not alter its state at the temperature of 0°. Its refractive powers
rather less than that of water; its specific gravity nearly 0-9, and
the pressure of its vapour about 3°7 atmospheres.

Mr. Faraday obtained dry ammonia from chloride of silver satu-
rated with this gas*, and, by the usual process, succeeded in con-
densing it. It was colourless, transparent, and very fluid. Its
refractive power surpassed that of water, and all the other liquids
hitherto described. The pressure of its vapour is equal to about
6°5 atmospheres at 50°, and its specific gravity is 0°76. Attempts
were made to obtain hydrogen, oxygen, fluoboracic, fluosilicic,
and phosphuretted hydrogen gases in the liquid state; but though
all of them have been subjected to great pressure, they have as
yet resisted condensation,

6. On the Application of Liquids formed by the Condensation of Gases
as Mechanical Agents. By Sir Humphry Davy, Bt. Pres. R.S.

In this paper Sir H. Davy anticipates the probability of the ap-

* See Quarterly Journal, yol, y. p. 74.

126 Analysis of Scientific Books.

plication of the elastic force of compressed gases to the movement
of machines. He founds this anticipation upon the immense dif-
ferences between the increase of elastic force in gases under high
and low temperatures, by similar increments of temperature. The
force of caaboni¢ acid was fouud to be equal to that of air com-
pressed to 3/5 at 12°, and of air compressed, to z/; at 32°, making
an increase equal to the weight of thirteen atmospheres, by an in-
crease of 20° of temperature.

7. On the Temperature at considerable depths of the Caribbean Seu.
By Captain Edward Sabine, F.R.S.

[In a Letter addressed to Sir H. Davy, Bart., P.R.S.]

Captain Sabine found the temperature of the water, at a depth
of 6000 feet, in latitude 204 N. and long. 83} W. near the junction
of the Mexico and Caribbean Seas, to be 45° .5, that of the sur-
face being 83°. He infers, that one or two hundred fathoms more
line, would have caused the thermometer to descend into water at
its maximum of density as depends on heat; this inference being
on the presumption that the greatest density of salt water occurs,
as is the case in fresh water, ‘at several degrees above its pein]
point.

8. Letter from Captain Basil Hall, R.N., ¢o Captain Kater, commu-
nicating the details of Experiments made by him and Mr. Henry
Foster, with an Invariable Pendulum; in London; at the Gala~
pagos [slands in the Pacific Ocean, near the Equator ; 3 at San
Blas de California on the N.W. Coast of Mexico; and at Rio de
Janeiro in Brazil. With an Appendix, containing the Second
Series of Experiments in London, on the Return.

The title is an abstract of the paper, and the follewing are the
most exact results obtained by Captain Hall at each station.

Diminution uf Gravity ee
From Poleto Equatos,| Ellipticity,

Length of Equat.
Stations, Pend.

Galapagos, 632 " NI .0051412 39.017196
San Blas, 21 30 . 0054611 39. 00904
Rio;.... 3 22°55 0053431 3901206

Philosophical Transactions. 127

9. Second Part of the Paper on the Nerves of the Orbit. By Chas.
Bell, Esq.

[Communicated hy Sir H. Davy, Bart., P.R.S.]

This is a continuation of the subject upon which Mr. Bell had
entered in his last paper. His object is to explain the reason of
there being six nerves distributed to the eye, and crowded into the
narrow space of the orbit. In this investigation he demonstrates,
that there is a correspondence between the compound functions of
an organ and the nerves transmitted to it. It is impossible to do
more, than here sum up the distinct functions of the nerves, as
unravelled by the skill of the author.

“ The first nerve is provided with a sensibility to effluvia, and
is properly called the olfactory nerve.

** The second is the optic nerve, and all impressions upon it ex-
cite only sensations of light.

“ The third nerve goes to the muscles of the eye solely, and is a
voluntary nerve by which the eye is directed to objects.

_ “ The fourth nerve performs the insensible traversing motions of
the eyeball. It combines the motions of the eyeball and eyelids,
and connects the eye with the respiratory system.

_“ The fifth is the universal nerve of sensation to the head and
face, to the skin, to the surfaces of the eye, the cavities of the nose,
the mouth and tongue.

‘« The sixth nerve is a muscular and voluntary nerve of the eye.

‘* The seventh is the auditory nerve, and the division of it, called
portio dura, is the motor nerve of the face and eyelids, and the respi-
ratory nerve, and that on which the expression of the face depends.

“ The eighth, and the accessory nerve, are respiratory nerves.

“ The ninth nerve is the motor of the tongue.

“ The tenth is the first of the spinal nerves; it hes a double root
and a double office; it is both a muscular and a sensitive nerve.”

Mr. Bell concludes his paper with a few very appropriate words
in favour of anatomy, as a means better adapted for discovery than
experiment,

‘“* Anatomy,” he observes, “ is already looked upon with pre-
judice by the thoughtless and ignorant: let not its professors un-
necessarily incur the censures of the humane. Experiments have
never been the means of discovery; and a survey of what has been
attempted of late years in physiology will prove, that the opening
of living animals has done more to perpetuate error, than to confirm
the just views taken from the study of anatomy and natural motion.”

With another opinion of Mr. Bell’s we cannot also but coincide,
and that is, that ‘* Medical histories do not often lead to the im-
provement of strict science.”

It is an opivion worthy the consideration of the Committee of
Papers of the Royal Society,

128 Analysis of Scientific Books.

10. An Account of Experiments made with an Invariable Pendu-
lum at New South Wales. By Major-General Sir Thomas Bris
bane, K.C.B. F.R.S.

[Communicated by Captain Henry Kater, F.RS., in a Letter addressed to

Sir H. Davy, Bart., P.R.S.]

The results of Sir Thomas Brisbane’s experiments are as follow:

39-07696 inches the length of the pendulum, vibrating seconds at

Paramatta; .0052704 the diminution of gravity from the pole to

the equator, and -->+,— the resulting compression.

11. Observations and Experiments on the daily Variation of the
Horizontal and Dipping Needles under a reduced directive Power.
By Peter Barlow, Esq., F.R.S., of the Royal Military Academy.

{Communicated by Davies GiLvert, Esq., V.P.R.S.]

The daily change of the horizontal needle is so small, that it has
only hitherto been detected with the most careful observations, and
with the most delicate instruments; and in the dipping needle, that
change is so extremely minute, as to have escaped observation al-
together. It occurred to Mr. Barlow, that it would be possible to
increase this deviation in both needles, so as to render it distinctly
observable, by reducing the directive power of the needle, by
means of one or two magnets properly disposed, to mask, at least
in part, the terrestrial influence. This idea was realized, and in
this way it is easy to produce a daily variation, to almost an
amount. From his experiments, Mr. Barlow draws the following
conclusions :—

1st. That while the north end of the needle is directed to any
point from the south to N.N.W. its motion during the forenoon is
towards the left hand, advancing to some point between the N.N.W.
and north; and while it is directed towards any point between the
north and S.S.E., it passes to the right hand, that is, still to some
point between the north and N.N.W.

2dly. That the daily change is not produced by a general de-
flection of the directive power of the earth, but by an increase and
decrease of attraction, of some point situated between the north
and N.N.W., or between the south and S.S.E.

3dly. That the dipping needle is subject to a daily variation,
which cannot, at present, be reduced to any fixed principles.

12. On the Diurnal Deviations of the Horizontal Needle when un-
der the influence of Magnets. By Samuel Hunter Christie, Esq.,
M.A., Fellow of the Cambridge Philosophical Society: of the
Royal Military Academy.

[Communicated by Sir H. Davy, Bart., P.R.S.]
Mr. Barlow communicated to Mr. Christie his method of ren-

Philosophical Transactions. 129

dering the variations of the magnetic needles more sensible, and he
commenced a series of observations in consequence of the commu-
nication. — :

He ascertained, that there was an easterly deviation before eight
o’clock in the morning, and that the greatest westerly deviation
took place about one o’clock in the afternoon. He also found,
that the state of the weather had a considerable influence upon
the nature and extent of the changes. But the most striking effects
seemed to him to arise from changes of temperature, and he adopts
the opinion that temperature, if not the only cause of the daily
variation, is the principal. He expresses his intention of entering
fully into the general question, when he shall have ascertained the
precise effects of changes in the temperature of magnets.

13. On Fossil Shells. By Lewis Weston Dillwyn, Esq., F.R.S.
[In a Letter addressed to Sir H. Davy, Bart., P.R.S.]

Mr. Dillwyn remarks, that every turbinated univalve of the older
beds, from transition lime to the lias, of which he can find any re-
cord, belongs to the herbivorous genera, and that the family has
been handed down through all the successive strata, and still in-
habits our land and waters. On the other hand, all the carnivo-
ruos genera abound in the strata above the chalk, but are compa-
ratively extremely rare in the secondary strata, and not a single
shell has been detected in any lower bed than the lower oolite.
‘He thinks, that a further examination will prove, that neither the
aporrhaides or any of those few undoubtedly carnivorous species,
which have been found in the secondary formations, were furnished.
with predaceous powers, but that they belong to a subdivision of
the trachelipoda zoophaga, which feed only on dead animals.

14. On the apparent Magnetism of Metallic Titanium. By William
: Hyde Wollaston, M.D., V.P.R.S.

In this paper Dr. Wollaston corrects an oversight in his former
communication upon metallic titanium. He therein stated, that
_ when the crystals from the slag had been freed from all particles

of iron adherent to them, they appeared to be no longer acted upon

‘by the magnet. He has since found, that although they are not
‘sufficiently attractive to be wholly supported by the magnet, yet,
‘when a crystal is supported by a thread, the force of attraction is

sufficient to draw it twenty degrees from the perpendicular. From

‘an ingenious comparison of different magnetic forces, he calculates
“that 51, part of iron, as an alloy in the metallic titanium, would
‘be sufficient to account for this power; and he shews, that it is
‘extremely difficult chemically to detect so minute a portion of iron,

on account of the high colour of the precipitates of titanium,

Vor. - XVII, K

130 Analysis of Scientific Books.

15. An Account of the Effect of Mercurial Vapours on the Crew of
His Majesty’s Ship Triumph, in the year 1810. By William
Burnett, M.D., one of the Medical Commissioners of the Navy,
formerly Physician and Inspector of Hospitals to the Mediter-
ranean Fleet. Communicated by Matthew Baillie, M.D., F.R.S.

The particulars of this curious case have been already published
by Dr. Baird, in Nicholson’s Journal, for the month of Oct. 1810.

16. On the Astronomical Refractions. By J. Ivory, A.M., F.R.S.

This is a very long and laborious investigation of the problem
of astronomical refraction; its result is a new table of refractions
with which the paper concludes, and which is compared with other
tables that have been long in the hands of astronomers, and the
characters of which are well established. Mr. Ivory shews that it
is fruitless to expect a near agreement in every single instance be-
tween observation and any table of refractions whatever, and that
there is no test of their accuracy except the smallness of the mean
error in a series of observations made at different times.

17. Observations on Air found in the Pleura, in a case of Pneumato-
thorax ; with Experiments on the Absorption of different kinds of
air introduced into the pleura, By John Davy, M.D., F.R.S.

This is a medical history which Dr. Davy has endeavoured to
illustrate by some experiments upon dogs. | He observes that the
‘circumstances which he has ventured to bring forward are some=
what favourable to the idea of the secretion or exhalation of azote,
but are still far from conclusive.

18. On Bitumen in Stones. By the Right Honourable George
Knox, F.R.S.

This is a second paper upon the same subject. Mr. Knox finds

bitumen in every thing except rock crystal and pearl-white
adularia.

19. On certain Changes which appear to have taken place tn the

Positions of some of the principal fixed Stars, By John Pond,
Astronomer Royal, F.R.S.

The Astronomer Royal thinks that his observations lead to the
conclusion that some variation, either continued or periodical,
takes place in the sidereal system, which producing but very small
deviations in a finite portion of time, has hitherto escaped notice.
The nature of this motion appears to be such that the stars are now
mostly found a considerable quantity to the southward of their
computed planes. With respect to the laws by which these
motions are governed, the observations in question, he admits, are
not sufficiently exact to throw any light upon them. ,

131

(lo the Editor of the QuarTerty Journat or Science, §¢.]

Manchester, March 1, 1824,

Sir,

Tur review of the 9th editionof my Elements of Chemistry, in the last
number of your Journal, contains some animadversions, to which I trust you
will dome the justice to insert a brief reply. It is not, indeed, my intention
to follow the reviewer through the variety of topics which he has introduced,
but to confine myself to a few of those, on which I am most desirous to be
set right with your readers, and which involve questions of some importance
. to chemical philosophy.

It has happened unfortunately that a passage, expressing doubts of the
correctness of the theory of volumes, which certainly ought to have been
expunged from the present edition of my work, was overlooked, owing to
one or two of the early sheets having been revised under circumstances dis-
advantageous to correctness. For this oversight, I am content to take
upon myself whatever blame it may justly deserve ; and I should have had
no reason to complain, had the reviewer pointed out the striking inconsis-
tency’of the passage, which he has quoted, with other parts of my volumes.
At page 299, vol.i., for example, I state, “analogy is certainly in favour of this
opinion, for the instances are numerous in which gaseous bodies observe the
law respecting volumes deduced by Gay-Lussac, and we have not at pre-
sent any well-ascertained exception to it.” The tenor of the whole work,
also, is inconsistent with the rejection of the theory of volumes imputed to
me ewe reviewer ; for almost every chapter affords examples of com-
pounds constituted in conformity to the law ; and at the close of the second
volume I have inserted, for the first time, a table exhibiting a general view
of such compounds.

_ The reviewer complains (p. 338,) that I have not given a more elaborate
and consistent account of the atomic theory, though he represents it (p. 339)
as requiring “ mystifications,” and particularly marks the distinction
between the atomic hypothesis and the theory of volumes. To a certain
extent, the law of volumes is, I admit, the expression of a general fact, of
which we have the indubitable testimony of our senses. But with regard to
certain elementary substances, which are not known to us separately in a
gaseous state, it is entirely matter of inference that their vapow’s unite in

olumes, which are either equal, or multiples or sub-multiples of each other.
We have, for example, no argument but from analogy, that this holds with
respect to carbon; nor, if we admit the probability of such combinations,
have we any decisive proof that the volumes, which have been assigned, are
actually the true ones. In all such cases, where we have not access to the
faets by direct experiment, the law of volumes rests on the ground of ana
logy only ; and is so far purely theoretical. ‘The law, also, however, well
established with respect to gaseous bodies, is limited to them only ; and we
must seek for some other principle, to explain the far greater number of
chemical combinations which take place between bodies existing under
other forms.

_ In the investigations which have led Mr. Dalton to the atomic system,
it appears to me that he has pursued no other method of reasoning than
that which has been followed by the most successful cultivators of natural
science, siuce the introduction of K 2 inductive logic, The theory of

«

132 Letter to the Editor, by Dr. Henry.

gravitation itself, however firmly it may now be established, took its rise in
an hypothesis founded on analogy, and could be considered as nothing more
than an hypothesis, till that period of the life of its great author, when the
coincidence was ascertained between the law which regulates the fall of
heavy bodies, and that power which preserves the moon in her orbit.‘ A
principle,” it has been remarked by the late Professor Playfair, “is often
admitted in physics, merely because it explains a great number of appear-
ances, and the theory of gravitation itself rests on no other foundation*.”
The term hypothesis, then, is far from being one of just reproach, since it
may be applied in a variety of cases to those first steps which it has been
found necessary to take in philosophical inquiries, and which have led
eventually to well-established laws.

The views of Mr. Dalton respecting the atomic constitution of bodies
appear to me to be founded mainly on the general fact, that bodies unite in
definite proportions. Of this general truth, Richter certainly furnished
the best and fullest evidences. Far from wishing to ‘‘ suppress” the share
of credit to whicli he is entitled, I have alluded to the table, calculated by
Fischer from his experiments ; but it is omitted in the appendix to the pre-
sent edition, merely because it has been superseded by the more extensive
tables of equivalents, which have since been constructed. ‘The law of com-
bination ia multiple proportions, the first experimental proofs of which are
due to Mr. Dalton, comes strongly in aid of the atomic theory, and fur-
nishes its most striking proofs and illustrations. Nothing can be more
evident than that if we set out from a binary compound, whose gaseous
elements exist in equal volumes, and proceed to compounds of the same
elements, in which either is found as a multiple in volume of the other, there
must, as the reviewer observes, ‘‘ be a perfect accordance between the ato-
mic hypothesis and the theory of volumes.” But the atomic theory is, [
contend, a wider and more comprehensive generalization, and includes the
Jaw of volumes as well as that of combination by multiples of weights. In
this ease, as in many others, when we advance from discovery to discovery,
ave do nothing more than resolve our former. conclusions into others still
gore general.

There can surely be nothing inconsistent with sound philosophy in in-
quiring why bodies unite in definite proportions, and why they unite in pro-
portions which are multiples or sub-multiples of weights or oF volumes ; and
the only satisfactory explanation, that has yet been given of these
facts is, that in those combining weights, which are represented by
equivalent numbers, are contained determinate numbers of ultimate particles
or atoms, and that from the relative weights of aggregates that combine, we
may deduce the proportions as to weight which the ultimate single atoms bear
to each other. As there-seems every reason to believe that chemical attrac-
tion is exerted, not between masses, but between ultimate particles or atoms
only, combination will then take place either between single atoms or when
either is in excess, the excess will be represented by some simple multiple of
the number of atoms. In this reasoning it is of course taken for granted that
matter is not infinitely divisible, a position rendered extremely probable by
‘a philosopher, to whose opinions the reviewer will agree with me in paying
the greatest deference. ‘‘ Now though we have not the means,” that
writer observes, ‘of ascertaining the extent of our own atmosphere, those
of other planetary bodies are nevertheless objects for astronomical investi-

* Playfair’s Works, vol. iy, p, 62, note.

Letter to the Editor, by Dr. Henry. 133.

gation ; and it may be deserving of consideration, whether, in any instance,

a deficiency of such matter can be proved, and whether, from this source, —
any conclusive argument can be drawn in favour of ultimate atoms of matter

in general. For since the law of definite proportions, discovered by che-’
mists, is the same for all kinds of matter, whether solid, fluid, or elastic, if

it can be ascertained that any one body consists of particles no longer divi-

sible, we can then scarcely doubt that all other bodies are similarly consti-

tuted ; and we may, without hesitation, conclude that those equivalent quan-

tities, which we have learned to appreciate by proportionate numbers, do

really express the relative weights of elementary atoms, the ultimate objects

of chemical research*.” A body so constituted (it is the scope of the —

which has been just quoted to shew) is found in the earth's atmosphere, all

the phenomema according with the supposition that it is ‘‘of finite extent, ’
limited by the weight of ultimate atoms of definite magnitude, no longer di-

visible by repulsion of their parts.”

But though the atomic theory, in its general outline, seems to me to rest
sufficiently on the evidence of facts, and on legitimate reasoning, yet there
are some positions which have arisen out of it, that may or may not be true, »
without, in the latter case, impeaching its general correctness. Of this na-
ture are the two cited by the reviewer, (p. 340) especially the first, viz.,
‘that an increase of the density of a gas indicates an incteased number of
simple atoms associated in the compound atom.” ‘This principle, I am»
ready to admit, may have been too hastily deduced ; for besides that it is at
variance with the view which J have adopted of the nitrous compounds, it
is inconsistent also with that which I have taken of the compounds of carbon
and hydrogen; olefiant gas, the binary compound, being denser than light
carburetted hydrogen, the ternary one. The other position, that ‘‘ of che-
mical compounds the most simple, is the most difficult to be decompesed,’’,
stands unimpeached, and is exemplified, as the reviewer himself remarks, in
the greater difficulty of decomposing nitrous oxide than nitrous gas. To
Mr. Dalton’s opinion of nitrous gas, which makes it the binary compound,
its greater facility of decomposition might present a reasonable objection.
But it is quite inconsistent with sound reasoning to frame a preposition out
of Mr. Dalton’s views and mine, which are completely at variance as to the
compounds of nitrogen, and to apply to that proposition the syllogistic me-
thod of reasoning as a test of its truth. No syllogism can be so constructed
as to involve in the same dilemma two persons, who disagree with each
other as to the conditional proposition on which that syllogism is founded.

Though I have adopted, as most probable, that view of the nitrous com-
pounds which makes the elements of nitrous oxide to exist in binary and
those of nitrous gas in ternary, atomic proportion, yetl consider the truth
of this opinion as far from being demonstrated That the volumes of the

elements of those two compounds are what they nave oeen represented by

Gay-Lussac, I entertain very little doubt, not only from the evidence of
other persons, but from methods of analysis which I have myself devised,
and which, though not otherwise important, than as they bring out the re-
sults by easy and summary processes, [ shall probably ere long lay before
the public. But it must still remain a subject of inquiry, whether equal
volumes of nitrogen and oxygen gases contain, as Mr. Dalton supposes,
equal numbers of atoms ; or whether, as [ take to be more probable, the
same number of atoms exists in one volume of oxygen as in two of nitrogen
gas.

. * Dr. Wollaston on the Finite Extent of the Atmosphere»—Phil, Trans, 1822.

134 Letter to the Editor, by Dr. Henry.

The illustrious author of the Elements of Chemical Philosophy will not,
T trust, require any assurance from me, that nothing could be farther from
my design, or more repugnant to my feelings, than to misunderstand
“intentionally” his ideas respecting chemical combination. I have, it is
true, rendered the word proportion by that of atom, but I have enclosed
the latter word in parentheses, purposely to shew that it was not the ex-
pression of the author, but my own interpretation of his meaning. The
fact is, that great ambiguity has arisen out of the use which has been made
of the word proportion. Strictly, the only numerical expressions of pro-
portion, that can be considered as “‘ the results of experiment,” must be de-
rived from a comparison either of the weights, or of the volumes, in which
bodies unite ; and it appears to me that a system of numbers, derived from
the consideration of weights, should be kept distinct from one derived from
aw comparison of volumes. But the numbers (1 and 15) representing hydro-
gen and oxygen, were gained from the joint consideration of the weight
and volume of the elements of water ; while those representing oxygen and
nitrogen (15 and 26) were derived from a comparison of the weights only
of the elements of nitrous oxide. Since, then, the word proportion could
not, in both cases, apply to a comparison of weights only, nor yet of vo-
lumes only, it was natural for me to conclude that it must bear a reference
to ultimate particles or atoms, the only other objects, which I could con-
ceive as, in this case, admitting of being compared.

These, Sir, are the only points respecting which I deem it necessary to
trespass on the attention of your readers, though there are others on which
1 am not disposed to concede the justice of the reviewer's strictures. In
some instances, I allow, he has pointed out mistakes that may call for cor-
rection on a future occasion, should any occur to me. Having invited the
communication of errors or omissions, with a view to the improvement of
my volumes, it would ill become me to feel “ offended” when that invitation
is complied with ; and all that I claim is to be animadyerted upon with a
reasonable share of courtesy and of candour.

Tam, Sir,
Your obedient and faithful servant,
WILLIAM HENRY.

135

Arr. XIII. PROGRESS OF FOREIGN SCIENCE.

In Volume XIII. p. 144, we briefly animadverted on some re-
searches of Professor Gmelin, of Tubingen, published in Dr.
Brewster’s Journal, about two years ago, where the terms refute,
and refutation were applied with more freedom, than propriety or
decorum, to Sir. H. Davy’s fundamental experiments relative to
the connexion of chemical affinity with electrical attractions, con-
tained in his Bakerian Lecture of 1806. M. Becquerel read to the
Academy of Sciences on the 7th June, 1823, an interesting paper
on the electrical effects which are developed during different che
mical actions, which perfectly accord with, and seem fully to con-
firm, the conclusions of the English philosopher. After a candid
retrospect of preceding inquiries on the subject, M. Becquerel thus
states Sir H. Davy’s theory: “ Supposing two bodies, whose mo=
lecules are in different states of electricity, and that these states
are sufficiently exalted to give them an attractive force, superior to
the power of aggregation, a combination will be formed. This is
the key of the electro-chemical theory.” ‘ Although Sir H.
Davy has advanced the opinion, that the substances which com+
bine are those which manifest on mutual contact, opposite elec-
trical states, yet we perceive from his own experiments that it is by
induction he extended this property to all the bodies which exert
chemical actions on one another; for instance, he was not able to
verify it on alkaline and acid substances, unless they were per
fectly dry. In other cases, the results were null. He adduces,
among others, pure potash, and sulphuric acid, which afford no
appearance of electricity at the moment of their combination. In
fact, this celebrated chemist could not recognise electricity in the
contact of two substances which are just combining ; for, adopting
the electro-chemical theory, as soon as the combination takes
place, the two electricities that were developed, recombine, and
probably form, by their union, caloric: whence, in making use of
a condenser to collect one of the electricities which is disengaged,
traces of this fluid ought to be found with difficulty, since the con-
denser requires a certain time to charge itself, during which the
two electricities may re-combine. But if a galvanometrical mul-
tiplier be employed, such as that of M. Schweigger, which renders
the electricities sensible at the very instant of their disengagement,
and consequently at the instant when the combination takes place,
currents will be obtained of greater or less force, according to the
degree of conductibility of the substances put in action, and that
of their reciprocal affinities; I say according to the degree of con-
ductibility, because when one of these substances conducts the

136 Progress of Foreign Scvence.

electricity ill, there is no current, although the chemical action be
very strong. The conductibility then is here an indispensable con-
dition. ‘ef

We shall examine in succession the electrical effects that we
have observed in different chemical actions by the aid of the multi-.
plier ; 72z.—1, At the moment of the combination of acids with
metals and alkalis.’ 2. In the dissolutions. 3. In the contact of
metallic oxides with the alkalis which combine with them. 4. In
the precipitates. As to double decompositions, it has been im-
possible for me to recognise the slightest trace of electricity at the
moment of their formation.

Electrical Effects produced at ihe moment of the Combination of the
Metals and Alkalis with the Acids.

We have seen above that Sir H. Davy observed electrical effects
on the contact of acids and alkalis, only when these bodies had
been perfectly dried. M. Cérsted asserts that he has perceived
them at the instant when the acid combines with the metal.

‘The following is the means which I employ to shew the elec-
trical effects in these species of actions. I make use of a galva-
nometer, whose wire is of platinum. (See p. 124 of this volume.)
At one of the extremities of this wire I placed a little platinum
spoon destined to receive the acid, which is selected of such a
nature as not to act on the platinum. To the other end of the
wire is adapted a piece of the same metal, between the branches of.
which (as pincers) the body is placed, which is to act on the acid.
In case the platinum could exert an electro-motive action on this
body, there is placed between them a bit of moistened paper. Let
us begin by shewing what electrical effects result at different tem-
peratures from the contact of a liquid with the platinum. At
the ordinary temperature, whatever be the liquid, provided it is
not nitro-muriatic acid, the electrical current is null, but when the
temperature is raised, phenomena occur which we shall endeavour
to explain. Let us put into the spoon distilled water, and let us
raise the temperature to ebullition, there will be no current in con-
sequence; if the water of the Seine be used, the current will be
extremely feeble, and it will increase in intensity by the addition
of a little nitric acid, or alkali. Now, since we know that boiling
nitric acid has no more action on platinum than cold nitric acid, it
is hence probable that the current is owing to the difference of
temperature of the two ends of the wire. It has been already
shewn in a former memoir that two pieces of the same metal, in a
sufficiently unequal state of temperature, pass, on their mutual
contact, into two different electrical states. This change of tem-
perature must therefore be avoided, which is done by using small

Progress of Foreign Science. 137

fragments of the bodies to be acted on, and a large platinum
spoon. :

Let us now fix in the platinum forceps a little bit of caustic,
soda, or potash, slightly moistened with water. At the moment
when the alkali touches the acid, an energetic electrical current
will take place, which will proceed from the acid to the alkali fol-
lowing the curcuit. ‘Thus at the instant of contact of these two
bodies the acid becomes enveloped with an atmosphere of positive
electricity, and the alkali with one of negative. The electrical
current is so strong that it may be observed without a galvanometer.
It is sufficient for this purpose to present the conjunctive wire to a
needle suspended at the filament of a silk-worm. In order to
observe the electrical currents which result from the action of an
acid on a metal, the same process is employed ; care only is taken
to prevent the metal touching the platinum directly, by interposing
a small slip of paper. The experiment is made in the same way,
and the result is the same, whatever be the acid and the base.
M. Becquerel next shews that during the solution of a body in
water, or alcohol, no electricity is produced. But the smallest
acid or alkaline particles are sufficient to modify the results.

He then details some experiments on the solution in caustic
potash of metallic oxides, such as oxide of zinc, and of lead newly
precipitated. In these, electrical phenomena were exhibited.
Whenever the oxide (generally contained in the thin ceecum of an
animal,) touches the alkaline solution, the needle deviates from its
magnetic direction, and the current goes from the oxide to the
alkali, passing along the wire. Hence in these kinds of combi-
nations, the oxides comport themselves like acids, and the alkalis
are always surrounded with an atmosphere of negative electricity,
as in their actions on the acids.

Tn slow precipitations, as when an infusion of nut galls acts on
sulphate of iron, a current is developed which goes from the infu-
sion to the sulphate. Let us puta solution of sulphate of mag-
nesia in contact with the caustic potash contained in the mem-
branous bag. The needle will deviate slightly from its direction,
and the current will be from the sulphate tothe alkali. In making
nitrate of barytes act on sulphuric acid, the current goes from the
acid to the nitrate. When two perfectly neutral salts were em-
ployed, as sulphate of soda, and nitrate of barytes, he has not been
able to discern the least appearance of a current.

In a subjoined notice, M. Becquerel describes the following
experiment. Take a plate of platinum, and placing it horizontally,
fix by cement, two glass tubes vertically upon it. Liquids poured
into these tubes will communicate through the medium of the pla-
tinum plate. Let us pour in any liquids whatever; if they are
susceptible of exerting chemical actions on the two ends of the
wire of the galyanometer which are immersed, there will be na-

138 Progress of Foreign Science.

turally established an electrical current, since the plate of platinum
permits the electricity to circulate from one liquid to the other.
Suppose one of these liquids to be concentrated, and the other
dilute nitric acid. On plunging into each tube an end of the cop-
per wire of the galyanometer, the experiment will shew that the
electrical current goes from the stronger acid to the other. Let us
now substitute, in the place of one of these acids, ammonia, which
dissolves the oxide of copper. At the instant of immersion of the
two wires the current will go from the acid to the alkali, and will
continue to move in the same direction, even when the acid shall
be diluted with water.——Ann. de Chem. et de Phys. xxiii. p. 244.

Heat. On the Property which some Metals possess of facilitating
the Combination of Elastic Fluids. By MM. Dulong and
Thenard.

After exhibiting to the Academy of Sciences Dobereiner’s in-
teresting experiment described in our last number, this gentleman
proceeded to detail some modifications of it which they had de-
vised. On immersing some spongy platinum into a mixture of
two parts of hydrogen and one of oxygen, explosion takes place.
If much azote be present, the water is slowly and actually formed.
The sponge of platinum, when strongly calcined, loses the property
of becoming incandescent; but in this state it produces slowly,
and without any very sensible elevation of temperature, the com-
bination of the gases. Platinum reduced into a very fine powder
by a well known chemical process, has no action whatever at the
ordinary temperature. The same is the result with wires or la-
mine. It might thence be supposed that the porosity of the metal
was an essential condition of the phenomenon, but the following
facts destroy this conjecture. Platinum was reduced into leaves,
as thin as the malleability of this metal allows. In this state the
platinum acts at the ordinary temperature, on the mixture of oxy-
gen and hydrogen, with the greater rapidity the thiner its leaf is,
They procured some which caused detonation after some instants.
But what renders this action still more extraordinary is the phy-
sical condition indispensable for its development. A very thin leaf
of platinum, rolled round a cylinder of glass, or suspended freely
in an explosive mixture, produced no sensible effect at the end of
several days. The same leaf crushed together like the wadding
of a musket, acts instantaneously, making the mixture explode.
Rolled leaves and wires at temperatures of from 200° to 500° cent.
act slowly, but without explosion.

Thin leaves of gold and silver act only at elevated temperatures ;
but always below that of boiling mercury. Silver is less effica-
cious than gold. In accordance with Sir H. Davy’s results with
palladium and platinum in the safety-lamp these gentlemen found,

Progress of Forevgn Science. 139

that these two metals, when of the same thickness, acted equally
well.

The oxide of carbon and oxygen combine, and nitrous gas is
decomposed by hydrogen at the ordinary temperature, when they
are in contact of the sponge of platinum. Olefiant gas mixed with
a proper quantity of oxygen, is completely transformed into water
and carbonie acid by the sponge of platinum, but only at a tem-
perature above 300° cent.

M. Thenard long ago shewed that iron, copper, gold, silver, and
platinum, had the property of decomposing ammonia at a certain
temperature, without absolving any of the principles of this alkali;
and that this property seemed to be inexhaustible. Iron possesses
it ina higher degree than copper, and copper more than silver ;
gold and platinum under equal surfaces. Ten grammes of iron
wire are sufficient to decompose, within a few hundred parts, a
current of ammoniacal gas pretty rapid, and kept up for eight or
ten hours, without the temperature exceeding the point at which
ammonia completely resists decomposition. A tripple quantity of
platinum wire, of the same size, does not produce a nearly similar
effect, even at a higher temperature.

Palladium, in a spongy mass, inflames a stream of hydrogen, as
well as platinum. Iridium under this form becomes very hot, with
the production of water; nickel and cobalt, in mass, determine at
about 300° cent. the union of hydrogen and oxygen ; lastly, the
sponge of platinum forms, in the cold, water and ammonia, with
nitrous gas and hydrogen, and acts also on a mixture of hydrogen
and protoxide of azote. M. Gay-Lussac’s hydrogen lamp answers
well for the experiment of ascension, as the hydrogen would issue
in a very small stream. By holding a very light bit of platinum
sponge, about three quarters of an inch, before the orifice, the efflu-
ent gas is instantly kindled. This is more convenient than the
trophorus plate.—Ann. de Chim. et de Phys. xxiii. 440,

On the Preparation of Oxide of Uranium. By MM. Lecanu and
Serbat.

The authors of this process, after having fused the pulverized
mineral (pech-blende,) with one half of its weight of nitre, washed
the mass which results from the operation, treated the residiuum
with nitric acid, evaporated the solution to dryness, and re-dis~
solved in water acidulated with the same acid, add to the solution
an excess of carbonate of ammonia, which, while it is sufficient to
re-dissolye the whole oxide of uranium, has no action on the car-
bonates of lead and lime. M. Laugier, in commenting on the
above process, recommends the use of one part and a half of nitre,
instead of half a part. ‘The solution containing the nitrate of am-
monia, and the carbonate of uranium is to be evaporated to dryness

140 Progress of Foreign Science.

and calcined, in order to get the pure oxide. M. Laugier advises
in preference to wash away with hot water the nitrate of ammonia, .
and to calcine the remaining carbonate of uranium which has in the
filter, a fine lemon yellow colour.—Journal de Pharmacie, March,
1823,

On the Oxides of Nickel. By M. J. P. Lassaigne.

The metal was purified by Laugier’s process. The protoxide is.
obtained from solutions in acids, it is of an ash-grey colour, gives
green solutions with acids, from which caustic alkalis precipitate
it of apple-green colour. Its constituents are

1 ATS 1) ete ee ae - 100

eye CR ie Se) oe 20
Whence the atomic weight of nickel appears to be 5. The deut-
oxide is of a brilliant black colour, having some analogy with the
peroxide of manganese. Ata red heat it gives up a portion of its
oxygen, and passes to the state of protoxide, It is prepared by
treating the hydrated protoxide with chlorine. M. Lassaigne’s
experiments on its composition, give —

Bead! ® gy FS) 5 pvelvat « +4100

Oxygen ...... at oe 39°44,
approaching sufficiently near to 40.

The sulphuret artificially made is of a brilliant yellow colour, like

iron pyrites, and is very brittle. It consists of

DHGRCL ~ 4 laste eta ghey DA + ant 100

MOREY ate pe. “we cose s “ay eee
or one atom of each.

He describes a chloride and bichloride, and an iodide, whose

constitution may be inferred from the above numbers.

On the Gaqnet y of Saturation of Delphia. By M. Feneulle, of
Cambray. '

Neutral Sulphate—Acid . . , 3:031 5-0
Delphia . . 96°969 16:0
Subsulphate—not distinctly characterized. It seems to have a
double dose of base. The muriate of delphia is amorphous like
the preceding. It is formed of
Muriatic Acid . . . 100 2°136
Delphia. . . . . 4675 100-000
There is also a submuriate. It consists of
ARI A jie, gl deOe
Delphia . « ~ 100-000

Progress of Foreign Science. 141

Facts subservient to the History of the Succinic and Benzoic Acids.
By MM. Lecanu and Serbat.

Subjected to the action of heat these acids comport themselves
in nearly the same way. They melt, then are volatilized, leaving
always a slight carbonaceous residuum. The difference of solu-
bility of these acids in water, as well as in the essential oil of
turpentine, establishes a remarkable difference between them.
While, in fact, at the temperature of 16° cent., water dissolves
scarcely an appreciable quantity of benzoic acid, and, at 100°,
only one-twelfth part of its own weight; 100 parts of water, at
16°, dissolve 20 parts. and at 100°, about 46 parts of succinic
acid. On the other hand, at the temperature of 16° cent. a
gramme of benzoic acid requires for solution only 249 parts of
essential oil of turpentine, and at 100° much less than its weight.
Hence the liquor, on cooling, concretes into a mass. Succinic
acid, even above 100°, dissolves in it very sparingly, although the
essence thereby acquires the property of reddening litmus pretty
strongly. Hitherto the property of separating iron from manga-
nese, forming with the first an insoluble salt, and with the second
a soluble one, seemed to belong only to the benzoic and succinic
acids. It is, however, met with in the camphoric and pyrolar-
taric acids. The last even, would appear even to be capable of
separating these metals more completely than succinic acid does.
Perhaps it would be advantageous, in regard to economy, to sub-
stitute it for this acid.

Succinic acid is not altered by being distilled into nitric acid,
diluted with its own weight of water. It is, therefore, not con-
vertible, like some of the other vegetable acids, into the oxalic.
Nitric acid becomes thus the most convenient agent for purifying
the succinic. The action of nitric acid on the benzoic has not
been. well investigated, even by these gentlemen; but it is not
transformed into the oxalic acid. Succinic acid affords with pot-
ash a very deliquescent salt; with soda, a salt unchangeable in the
air, or rather somewhat efllorescent, and crystallizing in plates like
nitrate of silver; with ammonia, a slightly deliquescent salt, very
soluble in water, and crystallizing in long prisms with four faces,
transparent and colourless. It occurs frequently in plates; with
barytes, a salt hardly soluble, which is obtained in the form of a
white powder, by evaporating its solution. They were prevented
by an accident from examining the salt that they had obtained with
benzoic acid.

These two acids precipitate copper, tin, silver; these precipi-
tates, insoluble in water, are re-dissolved with facility by acetate
of potash, and nitrate of soda, without the nitrate of potash, the
sulphate and muriate of soda appearing to possess the same pro-
perty.—Journal de Pharmacie, for February, 1823,

142 Progress of Foreign Science.

Memoir on the Milk of the Cow Tree (Palo de Vaca). By J.B.
Boussingault and Mariano de Rivero.

Among the astonishing vegetable productions that are met with
at every step in the equinoctial regions, a tree is found which yields
in abundance a milky juice comparable in its properties to the
milk of animals, and which is employed for the same purposes, as
M. de Humboldt witnessed at the farm of Barbula (Cordillere lit-
torale de Venezuela), where he drank some of the milky juice.
The tree grows in considerable numbers on the mountains which
command Periquito, situated to the north-west of Maracay, a
village to the west of the Caraccas. The vegetable milk pos-
sesses the same physical properties as that of the cow, with the
single difference, that it is a little viscid. It has the same taste.
In its chemical properties, it differs sensibly from animal milk.

It mixes with water in all proportions, and when thus diluted, it
does not coagulate by ebullition, The acids do not convert it into
clots, as happens to cow’s milk. Ammonia, instead of causing a
precipitate, renders it more liquid. This character indicates the
absence of caoutchouc. Alcohol occasions a feeble coagulation,
or rather renders the juice more easy of filtration, The recent
juice slightly reddens litmus. Its boiling temperature is the same
as thatof water. Exposed to heat, it exhibits at first the same
phenomena as cow’s milk. A pellicle is formed at its surface,
which prevents the disengagement of aqueous vapours. On re-
moving the successive pellicles, and evaporating it at a gentle
heat, an extract is obtained resembling frangipane; when the
action of heat is longer continued, oily drops are formed, which
increase according as the water is carried off, and finally afford an
oily liquid, in which a fibrous matter floats which becomes dry
and horny, as the temperature of the oil is raised. Then is dif-
fused the best characteristic odour of meat frying in grease. By
the action of heat, therefore, the vegetable milk is separable into
two parts, the one fusible and of a fat nature, the other fibrous and
of an animal nature. If the evaporation of the vegetable milk is
not pushed too far, and if the fusible matter be not raised to ebul-
lition, it may be obtained without alteration. It then possesses
the following properties :—

It is of a white slightly yellowish colour, translucid, solid, and
resists the impression of the finger. It begins to melt at 40°
centig., and when the fusion is completed, the thermometer indi-
cates 60°.. Alcohol of 40° (sp. gr. 0°817) dissolves it totally by
ebullition, and it precipitates on cooling. It saponifies with eaus-
tic potash, and with ammonia forms a soapy emulsion. Nitric
acid heated on it, dissolves and converts it into oxalic acid. It
resembles refined bees’ wax, and serves for making candles. The
fibrous substance is procured by decanting the melted waxy

Progress of Foreign Science. 143

matter, washing off the last portions of it with an essential oil,
squeezing the residuum, and boiling it a long time in water, to
volatilize the oil, the odour of which cannot, however, be thereby
completely discharged. Thus obtained, the fibrous matter is
brown, having been somewhat altered by the temperature of the
melted wax. It is tasteless. Placed on a hot iron, it twists itself
and swells up, melts and is carbonized, diffusing the smell of
broiled meat. Alcohol does not dissolve it; and hence by treating
the extract of the vegetable milk repeatedly with hot alcohol, the
fibrous matter is obtained white and flexible. In this state, it dis-
solves readily in diluted muriatic acid. It possesses the same
properties, therefore, as animal fibrine. Fibrine had already been
found in the milky juice of the Carica papaya, by Vauquelin. Be=
sides these two main constituents, the vegetable milk contains a
little sugar, a magnesian salt (not an (acetate), and water. It
contains neither caseum nor caoutchouc. By incineration, some
silica, lime, phosphate of lime, and magnesia were obtained. The
_ wax forms about one-half the weight of the milk.—Ann. de Chim.
et de Phys. xxiii. 219.

On the Hot Mineral Waters of the Cordilleras of Venezuela. By
the same.

The springs of Onoto issue copiously from gneiss. Their tem-
perature is 44°5 centig. Their height above the level of the sea,
is 702 metres. From the bottom of each reservoir, bubbles of
azote rise from time to time in great abundance. The springs of
Mariano have a temperature of 44° c., but in particular spots it is
from 56° to 64°. They contain a very little sulphuretted hydro-~
gen. They also rise from gneiss, and evolve azote. Silica is the

edominating ingredient in solution. Their height above the sea
as 476 metres.—Ann. de Chim. et de Phys, xxiii. 272.

Puysiotocgy.—On some recent Discoveries relative to the Nervous
System. By M. Magendie.

M. Magendie offers some proofs and illustrations of Mr. Charles
Bell’s beautiful investigations, on the distinction between the nerves
subservient to sensation and motion. An individual had lost the
use of his two arms for several years, but he had retained a lively
sensibility in these parts. He died, and on examining his body,
the posterior roots of the brachial nerves (as they issue from the
spine) were perfectly sound, while the anterior roots were evi-
dently altered, had lost their medullary substance, and were re-
duced to their membranous sheath. ‘The nerves give sensibility
or mobility to our organs, only because they are connected with
the spinal marrow; wheneyer they are insulated by a wound, or

144 Progress of Foreign Scvence.

any other cause, the part to which they go becomes motionless
and insensible, It was, therefore, of consequence to know if the
spinal marrow was not itself divided into two halves, the one de-
stended to motion, the other to feeling. M. Magendie has dis-
covered that the spinal marrow is formed, as it were, of two cords
juxta-posited, one of which is endowed with an exquisite sensi-
bility, while the other is, so to speak, a stranger to the property,
and appears to be reserved for motion. Since it is shewn by the
fine experinients of Legallois, that all the other organs, without
exception, derive from the spinal marrow their sensibility and
mobility, we are led to the remarkable conclusion, that we must
cease to seek for any one point in the whole body where the sen-
sibility and mobility are compounded together. Hence it seemed
very probable that, in persons who lose the power of moving,
while they retain their sensibility, and that reciprocally in those
who lose sensibility retaining mobility, there is a disease in the
one case of the motive cord of the spinal marrow, and in the

other of the sensitive. A lunatic of the hospital of Charenton, _

had lost, for seven years, the faculty of motion in the whole body,
although he retained its sensibility. He died last month. M.
Royer Collard, physician to the establishment, made the ‘spinal
marrow be examined with the greatest care, and found, in fact, a
very marked alteration in the whole motive portion of the spinal
marrow, while the portion where sensibility resides was perfectly
sound. ‘The centre of the spinal marrow is devoid of sensibility;
on touching it, no movements are excited in the body. It is on the
surface of this organ, that its properties are developed under the
double relation of movement and feeling. ‘Those who think that
the electric fluid circulates habitually in our nervous system, may
derive from this fact a new argument in favour of their opinion;
for electricity diffuses itself, as is known, on the surface of the
bodies which it pervades. It is unnecessary to remark, that the
facts above related, should have a great influence in the treatment
of different palsies. When the cerebral hemispheres of any ani-
mal are put out of condition for acting, the animal runs straight
forward, with singular rapidity, as if it were pursued. We might
say, that an irresistible force presses and precipitates it. If, on
the other hand, the action of the cerebellum be stopped, the
moyements take an entirely opposite direction. The animal draws
back; and it is a remarkable phenomenon to see a bird, for ex-
ample, whose cerebellum has been slightly touched, for whole
days make no attempt to walk, swim, or fly, unless it be back-
wards. It would seem, therefore, to result from these experiments,
that an animal in the ordinary state of health, is placed between
two forces, which make an equilibrium, of which one would push
it in advance, while the other would push it backwards. Volition
would have the power of disposing at its option of these two forces.

\

Se

Progress of Foreign Science. 145

A disease of the horse, little known, was proper to verify the
precision of these results. Veterinary surgeons call this disease
wmmobility; and, in fact, when it is wished to make the animal
seized with it, fall back, whatever effort be employed, and what-
ever means be taken, it stands motionless. ‘The forward move-
ments are, on the contrary, easy, and seem sometimes to occur
even without the participation of the will. If the inference whick
I have drawn be exact, the disease ought to consist in a physical
alteration of the cerebrum, or in some obstruction of the action of
this organ. I caused to be examined, last month, two horses at-
tacked with immobility, and the conjecture has been completely
verified. In both the cerebrum was visibly altered; the cerebel-
lum, on the contrary, was unaffected. It appears, then, to be de-
monstrated, that the two opposite motive forces of the cerebrum
and cerebellum exist in animals, and that, in certain cases, they
may be withdrawn from the influence of the will. M. Magendie
relates a case of a man somewhat similarly affected, who was
cured by some grains of sulphate of quinina.—Ann. de Chim. et de
Phys. xxiii. 429.

Prussiate of Iron as a Cure of Intermittents.

Doctor Zollickoffer, of Baltimore, has employed this substance,
and his success has been as remarkable as with cinchona.—Journ.
de Pharm. July, 1823.

Injection of a Solution of Opium into the Veins of an Hysterical
Patient. By Charles W. Coindet.

This experiment was made at Edinburgh, and the result was
such as to deter any young physiologist from repeating it in hys-
teria. The patient was seized with violent spasms, constituting a
case of idiopathic tetanus. They commenced very regularly by
attacks of emprosthotonos, the head frequently striking the knees
with force, Opisthotonos succeeded; the body took the form of
a bow, and rested only on the heels and occiput. All the muscles
of the body participated in this state of painful tension, which, one
time, lasted twenty-seven minutes. The respiration was performed
with difficulty, the pulsations of the heart became feeble and ir-
regular, and the young girl (fourteen years of age), was threatened
with suffocation. This horrible agony was succeeded by some
convulsions of pleurosthotonos, which terminated the paroxysm.
Dr. Coindet dissolved a scruple of common opium in an ounce of
distilled water, heated to the temperature of 80° cent. At half-
past seven in the evening he began the injection, assisted by his
friends MM. Hercy and Lucius O’Brien. He made an opening in
the right basilical vein, with an ordinary lancet as for blood let-
Vor, XVII. L

146 Progress of Foreign Science.

ting. He removed the bandage from the arm; he then introduced.
the pipe of a syringe, and threw a drachm and a half of the solu-
tion into the vein, taking care to exclude every portion of air,
though the experiments of Nysten had shewn that a few air bub-
bles would occasion no mischief. The breathing was immediately
affected, becoming more regular, less rapid, and less convulsive. The
pulse and other symptoms remained as before. The successive in-
jections were repeated at intervals of five minutes. At the second,
the breathing became quite natural; the pulse rose to 100, and
was fuller. The skin became slightly coloured, and was soon
covered with a faint perspiration. The spasms lost their violence;
she heaved one or two sighs, like a person coming out of a pro-
found sleep. After the fourth injection she recovered her hearing,
but not her sense of sight. At the fifth, she began to see, and
articulated some phrases distinctly. The operation was not fol-
lowed with any disagreeble symptoms. On the following day, the
girl described her sensations with much clearness. At every in-
jection, it appearedvas if a torrent of fire had been poured into her
veins, which rising up her arm, and following the course of the
vessels, which she pointed out very exactly, passed under the
clavical of the same side, and concentrated its operation for some
instants on the chest, whence it proceeded to the head and along
the back, from which it diffused itself through the whole system,
and produced lively prickings and an intense heat in the skin.
She spoke of her sensations as having been very painful. After
six weeks of convalescence, she relapsed into a similar state of
disease to that for which the injections were used. She finally re-
covered from the convulsive affections by sea bathing; but was
afterwards seized with swelling of the mesenteric glands.

Dr. Coindet says, we must not expect from opium injections any
thing more than the temporary cessation of the spasms, whereby
the stomach may be brought back to its natural functions, which
interval must be taken advantage of, for administering the suita-
ble remedies, by the customary passages.— Bibliotheque Univer-
selle, May 1823.

Economics.—M. Viney one of the editors of the Journal de
Pharmacie, has given, in the number for February last, the fol-
lowing recipe for making a fetid and bitter solution, capable of
destroying all kinds of insects: —

Take of wood mushrooms, or large brown fetid boletuses 6 pounds
Black soap ‘ : :
Grated nux yomica_ . 2 ounces
Water. : . + 200 pounds

The mushrooms bruised and beginning to putrefy, are to be put
into the water holding the soap in solution. The mixture is to
be left to putrefy in a cask for some days, care being taken to agi-

Progress of Foreign Science. 14?

tate the liquid from time to time. When it has become very fetid,
the decoction of the nux vomica in water is to be poured in. This
liquor is employedto sprinkle the objects from which insects are
to be repelled, whether in gardens or elsewhere, taking care not
‘to use it on gildings or polished metals, which it would blacken.
The insect cannot stand this fetid poison.

Art. XIV.—MISCELLANEOUS INTELLIGENCE.

I, Mecuantcat Science.

' 1. Remarks on Iron Wire Suspension Bridges.—The following
remarks on this subject are from a memoire by M. Dufour, the En-
gineer of the Geneva bridge, briefly mentioned at page 369 of the
Jast volume of this Journal: they are naturally connected with the
account of that bridge.

Speaking of the comparative strength of iron in wires and in
bars, (see p. 367 last vol.,) M. Dufour says, ‘“‘ The immense ad-
vantage of employing iron in wire rather than in bars, is thus
rendered evident: it is more manageable, its strength is double,
the strength may be better proportioned by putting the number of
wires necessary to the resistance required, and a certainty is ob-
tained of the state of the interior parts of the suspending lines,
which nothing can give when large bars are used.”

“It appears at first that the minimum of the force of the wire
should be calculated upon, and not the mean; but as each bundle
contains many wires, although there may be some of a smaller
strength, there will be others that will surpass in strength, and thus
the mean should be used in estimating the strength of the whole,
although in employing a single wire the minimum only ought to
be taken.”

_ With regard to the Geneva bridge, M. Dufour says that after a
period of four months in which the bridge had been in full use, it

ad not suffered. the slightest alteration in its primitive form,
‘The path has retained the degree of curvature given it at first,
and no sensible lengthening of the wires has occurred. The
bridge, however, has been well tried, curiosity has taken great
numbers of persons on to it at once, and all the large stones re~
quired in the latter part of the work, were taken over it on car
tiages without the slightest damage. The elasticity of the bridge
is also what it was at first, a man walking with a moderate step does
not at all disturb the steadiness of the path; on walking quickly
there are slight vibrations produced, but no oscillations, and the
vibrations are such as never to be communicated from the one
bridge to the other, or in any Hp to affect the masonry.

2

148 Miscellaneous Intelligence. ©

The expense of the bridges was as follows :—

Masonry of the abutments, $c. . . . 4100 francs.
lodges, stations, §c.. . 3800
Forged iron, §c., for the gates. . . - 2800
Iron wire and workmen . . . » . - 1940
Wood-work required, workmen, Jc. . 2250
Lead, copper, tin, varnish, Jc. . . - 800
Terraces for the parapets, foundation, §c. 160
Various expenses . . . . . + ~ + 4500

oe

16,350

Bib. Univ. xxiv. 297.

2. Test for the action of Frost on Building Materials, by M. P.
Brard.—MM. Lepeyre and Vicat knowing that I had been long
occupied in the study of mineralogy as applicable to the arts, en-
gaged me in an investigation of the means best adapted to distin-
guish such stones, as, being otherwise fit for building materials,
gave way to the action of frost. I found it impossible in this
respect to ascertain any thing from their mineralogical characters,
and was obliged to follow another course. During the winter of
1819, I carefully examined with a lens the chalky limestone of
the neighbourhood of Perigueux, and the sandstone of the
coal basin of la Vezére, both equally liable to this action, I
soon found that each scale of the limestone, and each grain of the
sandstone was raised by the re-union of small needles of ice, which
when they melted suffered the particles to fall and collect about
the stone, and that where particles had fallen off in this way, a
fresh succession was raised in the same manner, and ultimately se-
parated from the mass.

I was struck by the resemblance of. the ice in silky crystals to
the saline efflorescences which appear between the plates of cer-
tain shists and on the surface of old walls. I remembered the ef-
fect of common salt on bad pottery, and on the saline rocks of
the Tyrol, and conceived the idea of substituting the action ofa
saline solution to that of common water. After various experi-
ments, I gave the preference to sulphate of soda, its effects being
the most constant and most comformable to the action of frost.

The experiment that it may lead to satisfactory results should
be conducted as follows. Suppose an excavation newly made
into limestone or other rocks, and it be desired to ascertain the
liability of the rock to disintegration by the action of frost.

lst. A cube of two inches in the side is to be cut from each
part to be tried; the various cubes numbered with thick China
ink, and their original sites also marked.

Mechanical Science. 149

2nd. About four pints of common cold water is to be saturated
with sulphate of soda, so that a few grains of the salt shall remain
undissolved.

8rd. This solution is to heated to ebullition, and then all the
cubes to be entirely immersed in it. When the boiling has recom-
mencéd it is to be continued for half an hour.

4th. The cubes are to be withdrawn from the solution and
placed each one in a saucer, numbered as the cube is; a small
quantity of the solution is to be poured on to each cube, and the
whole left until covered with white efflorescences perfectly analo-
gous in appearance to the rime or hoar frost, which causes the dis=
integration of the stones. These efflorescences will appear in
about twenty-four hours if the air is dry or hot, but in a humid
atmosphere are sometimes five or six days.

5th. When the efflorescences appear on the angles and sides of
the cubes, they are to be dissolved again by means of a few drops
of water, or better still with a little of the solution in which the
cubes were boiled. If well managed the efflorescences will soon
re-appear, and when well formed, are again to be removed ina
similar way, and this is to be repeated for three or four days toge-
ther *; after which each cube may be washed with abundance of
common water, but without removing it from the saucer.

6th. The specimens to be tried having been washed on all their
faces, the detached matter is to be examined, and a judg-
ment formed from it, of the relative qualities of each kind of
stone submitted to the proof: for the greater the number of the de-
tached particles collected in the saucer, the more liable is the
stone to be attacked by frost; the smaller the number the more
capable is it of resisting the action.

As yet, all the results of this test have accorded perfectly with
the effect of time and frost. Such stones as have been found to
disintegrate by frost have given way to the salt, such as time has
sanctioned have resisted the new agent, so that the mechanical
effects of the two are perfectly analogous, Crystallization takes |
place with both, augmentation of volume, efforts on the surfaces
of the small cavities containing the water or solution, and if the
aggregation be not sufficiently powerful to resist the action, dis-
ruption, and a gradual decay of the rocks either in their natural
sites, or if they have been applied to use in their new situations.
The action of the sulphate of soda being quite mechanical, is ex-
erted indifferently on all kinds of rocks deficient in aggregation,
on limestones, sandstones, large grained granite, granites of too
micaceous a structure, shists, lavas, &c. It may be employed as
a proof or test also even upon slates, bricks, tufas, mortars, and
cements, as is proved by a table of various results of this kind.

* If the proof be continued for a longer ames good building stones may be
rejected, for the prolonged action of the salt is more powerful than that of ice,

150 Miscellaneous Intelligence.

The above is freely translated from a paper inserted by
M. Brard, in the Bib. Univ. xxiv. 224.

3. On the Strength of Cast Iron and other Metals.—It was our
intention to have noticed a new edition of Mr. Tredgold’s valuable
essay on the above subject, in a former part of our Journal, but
this has been prevented by the pressure of other matter. We
must, therefore, rest satisfied with laying before our readers the
contents of the eleven sections into which the work is divided,
reserving to a future occasion a more explicit account of its
contents.

The First Section consists of introductory remarks on the use
and the qualites of cast iron; and of cautions to be observed in
employing it. This section is followed by three extensive tables,
which will often save the practical man a considerable share of
trouble in calculation.

The Second Section explains the arrangement and use of the
tables, which precede it ; and in this edition, the number of popu-
lar examples is much increased.

It is a common and a well understood fact, that an uniform
beam is not equally strained in every part, and therefore may be
reduced in size, so as to lessen both the strain and the expense of
material.

The Third Section points out the value of cast iron, in this par-
ticular, and the forms to be adopted for different cases,

The Fourth Section contains a popular explanation of the
strongest forms for the sections of beams; the construction of
open beams ; and the best forms for shafts. A due consideration
of these two sections will enable the young mechanic to guard
against some common errors in attempting to apply these things to
practice. They are much augmented, and a new principle of con-
structing bridges is explained in the fourth section, _

The Fifth Section is wholly devoted to experiments on cast
iron; it will be found to contain, in addition to the author’s expe-
riments, almost all of the experiments that have been described
by preceding writers.

To this section a great many new experiments have also been
added, to show the relative strength of iron of different qualities ;
and also seven new experiments on torsion, made by Messrs.
Bramah. The section concludes with the result of the author’s
observations on the relation between the appearance of the
fracture and the strength of cast iron as determined by expe-
riment.

The Stath Section contains experiments on malleable iron and
other metals, and is entirely new. The effect of hammering and
the decrease of force by heat, are experimentally examined ; and

Mechanical Science. 151

the cause of English iron being inferior to Swedish, for particular
purposes, is pointed out.

In the Seventh Section we are shown how to obtain some of the.
most useful practical rules from the first principles that are fur-
nished by experience.

The Eighth Section treats of the stiffness to resist lateral strains,
with its application to some interesting practical cases.

The Ninth Section is on the strength and stiffness to resist tor-
sion or twisting, with its application to machinery.

The Tenth Section treats of the strength of columns, pillars, and
ties, with some new examples. It may be useful to remark, that
the most refined methods of analysis have been applied to the same
subjects by Euler, Lagrange, and other continental mathemati-
cians, without arriving at results more accurate, more simple, or
more convenient in practice.

In the Eleventh Section the author considers the resistance of
beams to impulsive force. In this section will be found many im-
portant rules, with examples of their application to the moving
parts of engines, bridges, &c., wherein the advantage gained by
employing beams of the figures of equal resistance is shown.

The Eleventh Section is followed by an extensive Table of the
Properties of Materials, and other Data, often used in Calculations,
arfanged alphabetically, and in this Edition much enlarged. By
means of this table the various rules for the strength of cast iron,
contained in this work, may be applied to several other kinds of
materials.

A Note, added at the end of the table, on the chemical action of
some bodies on cast iron, will be read with interest by those who
employ cast iron where it is exposed to the action of sea water.

4, On the Capillary Action of Fissures, ye.—M. Dobereiner has
remarked a singular effect produced apparently by fissures. Hav-
ing filled a large glass flask with hydrogen, and left it standing
over water, it was observed some days after, that the water had
risen in it above one-third of its capacity. The only cause for this
effect that could be assigned was, the existence of a very minute
fissure in the glass. Filled a second time and left over water,
the fluid had risen in it above an inch and a half in twelve hours,
and in twenty-four had risen two inches and three quarters, during
which time the barometer and thermometer had not sensibly al-
tered. In other experiments, vessels of other forms were used,
and the water uniformly rose in those having fissures.

When one of these vessels filled with hydrogen was covered by
a bell glass, or when the vessels were filled with atmospheric air,
oxygen, or azote, instead of hydrogen, no change took place. —

M. Dobereiner considers the effect as due probably to capillary

152 Miscellaneous Intelligence.

action. He suggests that all gases may be considered as consist-
ing of solid atoms of various sizes, enveloped by atmospheres of
heat also very different, and that hydrogen though it has the largest
atmosphere of heat, has the smallest atom, and is thus permitted
to escape by fissures, which retain the other gases. “ Probably,” he
says, ‘‘ fissures may be formed which will permit azote to pass, but
not oxygen, and others again which will let the oxygen out, but
not carbonic acid gas.”

Another experiment which seems related to this subject is as fol-
lows :—A thermometer-tube had been drawn out very fine in the
lamp, and it being desired to have it filled with alcohol, the
point was immersed in that fluid, and the bulb heated until no more
bubbles of air escaped; the tube was then cooled, but no alcohol
entered. When again heated abundance of bubbles of air passed
out through the alcohol, though when recooled no alcohol would
enter. Upon examining the tube with a lens, nothing was seen which
could prevent the entrance of the alcohol ; on withdrawing the tube
from the alcohol, the external air entered with a hissing noise.
M. Dobereiner conceives that the diameter of the tube was so
small that the alcohol could not enter, but only the air which it
contained.—Ann. de Chim. xxiv. 332.

5. Sound produced by opening a Subterraneous Gallery.—In the
road made by Napoleon communicating between Savoy and
France, and which passes by Chamberry and les Echelles, there
is, as is well known, about two miles from the latter place, a gal-
lery cut in the solid rock, twenty-seven feet high and broad, and
nine hundred and sixty feet in length. Mr. Bakewell states in his
travels, that this gallery having been commenced at both ends,
when the excavations from each end nearly met, and the thin par-
tition of rock between them was first broken through by the stroke of
the pick,a deep and loud explosion followed resembling thunder.
The cause of this explosion Mr. Bakewell thinks is easily explained.
The air on the eastern side of the mountain being sheltered both
on the south and west from the sun’s rays, must be frequently
many degrees colder than that on the western side. The moun-
tain rises full one thousand feet above the passage, and at least
fifteen hundred feet above the bottom of the valley, forming a
partition between the hot air of the valley, and the cool air of the
ravines on the eastern side, and a sudden opening being made for
the dense air to rush into a rarer medium, must necessarily pro-
duce a loud report, just as a bladder does upon bursting in the
rare air of a receiver. ‘The sound of the explosion being greatly
increased by reverberation through the long archway on each
side.—Bakewell’s Travels.

This explanation of the origin of the sound seems insufficient to
us, inasmuch as it would require a much greater difference of ba-

‘

Mechanical Science. 153

rometric pressure on the opposite sides of the previously existing
partition of rock than probably existed. ,

6. Nautical Eye-tube.—A trial has been made on board the Clio
among the Orkneys, and in the Moray Frith by Mr. Adams, of
the performance of his eye-tube to the telescope of a sextant for
taking altitudes when the horizon is invisible. In making the ob-
servations the horizon was always screened from the instrument,
and under these circumstances after rejecting a few observations
the mean difference of 199 altitudes of the sun, moon, and stars,
taken by the eye-tube, from those taken at the same time in the .
ordinary way by the officers of the Clio, and corrected for dip,
amounted to only 1’10”. The altitudes taken by the eye-tube
are not affected by any dip or depression of the horizon. Consider-
able care and practice is required in the use of the instrument, but
that attained, the latitude, the time at the ship, and consequently the
longitude may all be determined by it when the horizon is invisi-
ble. By means of it also either the large or the pocket sextant
may be employed on shore as a substitute for the theodolite, upon
making the necessary allowance for the parallax of the instrument
in the name of index, error, which oa becoming sensible, must vary
inversely with the distances of the reflected terrestrial objects.—
N. M. Mag. xii. 16.

7. Leghorn Straw Plait.—The Dublin Society having offered
premiums for the best imitations of Leghorn plait, awarded three
prizes to successful candidates. Not less than twenty-four speci-
mens were exhibited from widely remote parts of Ireland. The
finest specimen was made from avena flavescens, or yellow grass,
by Miss Collins of Plattin, near Drogheda. The second was
made of cynosurus crystatus, or crested dog’s tail, by Miss Grimley
of Kiltinon, near Newton Mount Kennedy. The third of agrestis
vulgaris, or common bent grass, by Miss Campbell of Lon-
donderry.

IJ. Cuemican Science.

1. On Fulminating Silver and Mercury.—The following results
are collected from a memoire on these substances, by Dr. Just
Liebeg, which has appeared in the Annales de Chim. xxiv. 294.

The fulminating silver was obtained by dissolving about 60 grains
of fine silver ia half an ounce of nitric acid, spec. grav. 1,52, add-
ing two ounces of alcohol of spec. grav. .85, and heating slowly
in a flask until ebullition commenced ; in a short time, white crys-
talline flocculi appeared, the vessel was removed from the source
of heat, and left to cool. The ebullition continued some time, and

154 Miscellaneous Intelligence.

the deposit augmented. The vessel should not be cooled hastily
in this process, as great loss of the compound is occasioned.

Thus prepared, the fulminating silver appears in white silky
acicular crystals, possessing the well known detonating properties,
perfectly soluble in 36 parts of boiling water, and re-crystallizing as
the solution cools. It has a metallic taste, stains the skin, if
exposed to air becomes first red, then black, and to test papers
appears as a neutral salt.

Fulminating mercury was prepared according to Howard’s process:
100 grains of mercury being dissolved in half an ounce of concen-
trated nitric acid, and two ounces of alcohol added. Heat is then to
be applied, as in the former case. At firsta little nitrate of mercury
is deposited, but is soon redissolved, and then ona sudden the liquor
becomes grey from the reduction of part of the oxide of mercury,
and the liberation of a dense vapour, occasioned by the volatiliza-
tion of a portion of mercury with the ether that rises. After some
time the liquid becomes yellow, and dendritical crystals appear,
which augment on cooling until nearly a quarter of an inch in
length. ‘hey are greyish-white, harsh to the touch, and heavy,
but when purified by being dissolved and crystallized two or three
times, appeared as perfectly white brilliant silky crystals, having a
mild metallic taste, and detonating violently by a blow. ‘They
are pure fulminating mercury.

On adding lime-water to fulminating silver the latter dissolved,
leaving a little black oxide of silver; when a few drops of nitric
acid were added to the clear solution a white precipitate fell, which
detonated like the original compound. It now dissolved without
any residue in lime-water, and was precipitated again by acid, as
before, without any indication of decomposition.

Substituting potash for lime-water, and boiling, exactly the same
effects took place. The fulminating silver combined also in the
same manner with magnesia, baryta, strontia, soda, and ammonia,
and with all of them presented the same phenomena, except that
ammonia did not cause the separation of oxide of silver. The
quantity of oxide separated by the alkaline bases from 100 of ful-
minating silver was 31.25,

Thus it appears that fulminating silver perfectly resembles a
compound salt; its acid combines with the alkalies, &c., and its
base, the oxide of silver, separates; and in confirmation of this view
of its nature it was found that compounds of the acid, and all other
bases, might be obtained perfectly definite and crystallized, and
possessing strong detonating properties.

A quantity of fulminating silver was decomposed by lime, the
liquid filtered, concentratel, and carefully precipitated by nitric
acid, excess of the latter being avoided. The new acid, when well
washed, appeared as a white powder, very soluble in boiling
water, reddening litmus paper, and crystallizing on cooling.

Chemical Science. 155

Researches were then made into the nature of this acid: the
term fulminate, has been applied to the salts containing it. Mu-
-Tiate of potash added to fulminate of potash produced no precipi-
tate of chloride of silver; but muriatic acid decomposed the salt,
and chloride of silver, muriate of ammonia, hydrocyanie acid and
earbonie acid, resulted. Fulminate of potash does not preci-
pitate persulphate of iron, nor does the addition of muriatic acid
form a prussiate of iron, , Metallic copper precipitates all the silver
from fulminate of potash, and a plate of zine indicates the copper
present; but excess of potash does not separate the copper, nor
‘does the fluid become blue by adding ammonia, though when the
solution is decomposed by npuriatie acid, the copper is easily found
by those tests. Chromates, prussiates, and carbonates, do not
precipitate the silver from alkaline fulminates; these properties
point out a strong analogy between this acid and the metalliferous
cyanic acids.

The fulminating acid boiled with oxide ofsilver, gave fulminating
silver; boiled with oxide of mercury, it produced a compound in
small brilliant plates.

Conceiving from analogy that the acid of fulminating mercury
differed from that of fulminating silver in the substitution of the
former metal for the latter, experiments were made to ascertain
this point; crystals of fulminating mercury boiled with potash,
deposited oxide of mercury, and the fluid, when precipitated by
nitric acid, gave.a white precipitate, which, when dry, detonated
strongly by percussion; with baryta, strontia, and lime, similar
compounds to those formed by fulminating silver, were produced.
The separation of the acid from fulminating mercury does not al-
ways succeed. In only two operations out of eight was the acid
obtained in yellow detonating crystals.

A quantity of fulminating silver was put with metallic mercury
into water and boiled ; after some time the liquid became turbid, it
was filtered, and furnished crystals exactly the same as those pro-
duced by the acid of fulminating silver and the oxide of mercury.
Boiling another portion for a much longer time, the precipitate
deepened in colour, and when no more was formed, the whole was
filtered and crystallized. The crystals were very fine, and pure
fulminating mercury; and an amalgam of mercury and silver re-
mained. ‘Ihe reverse operation was performed of preparing ful-
minating silver from fulminating mereury; the latter was boiled
with silver which had been precipitated from the nitrate by copper,
and to which a quantity of platina filings had been added; by the
galvanic action of the two metals the mercury was precipitated,
‘and the silver dissolved. The experiment requires rapid manipu-
Jation and simple decantation, otherwise the crystals will always
‘contain mercury.

Fulminating silver was boiled with copper; the silver precipitated,

156 Miscellaneous Intelligence.

and the liquid, which was found to contain copper, after some time
deposited a bluish-green powder, which behaved like a true com-
bination of oxide of copper with the acid of the fulminating silver,
containing copper in place of silver. The compound detonated
more feebly than that of silver, and was difficultly soluble in boil-
ing water ; on evaporating the mother liquor, a large quantity of
fulminating copper was obtained. Zine gave similar results, but
mrretrerterdn Iron also produced a crystallized fulminating com-
ound,

! When fulminating mercury was acted on by the metals, similar
phenomena were produced; and fulminating copper and fulmina-
ting mercury were thus obtained.

When fulminating silver was boiled with magnesia, the liquid
was found to contain but very little of the acid, but a reddish pre-
cipitate had formed, which, though it contained the greater part of
the fulminating mercury, merely decrepitated feebly when thrown
upon ahotcoal. Half an ounce of it heated in a retort, decomposed
quietly, yielding a portion of carbonate of ammonia and water, and
carbonic acid gas, no other gas being liberated. In order, there-
fore, to obtain a knowledge of the constituents of fulminating sil-
ver, 100 parts were well mixed with 400 parts of calcined mag-
nesia, and heated in a luted retort, the products being carefully
received and estimated. They were,

With fulminating silver With fulminating mercury
Carbonic acid . . 35°5
Ammonia ty ss era Zips ay eed OF
Welter uy hiy erro! Valet apes
Silver . . . . 41°0 . Mercury 56:9
Deas bs are eee ai wines ee

100° 100-

These being the mean of four experiments on each compound.
The only substance which varied was the carbonic acid, and the
proportions of the other substances remained constant. These gave
as the ultimate elements,

Fulminating silver Fulminating mercury
Oxygen . . -» 32°22... . ~ 23°39
Hydrogen. | s . BH2D wa VY BeBe
Witrogen’ 145.) 4, SVE 2B A 4 Paes Gees
Carbon.) 3 0a SRG8 isis ee Be A

Silver . . . 41:00 . Mercury 56°90

The following are some of the compounds of the acid of fulmi-
nating silver with bases. —Magnesia combines in two proportions
with the acid: one is a rose-coloured powder, not soluble or deto-
nating, but merely decrepitating by heat; the other is in beautiful
white filamentous crystals, resembling capillary silyer, and

Chemical Science. 157

strongly detonating.—Baryta combines with the acid apparently
in two proportions ; the first crystallizes in dull white grains, which
detonate powerfully, and are difficultly soluble in water.—Strontia
resembles baryta in its compounds.—Zinc forms a salt in small
yellow granular crystals, very soluble, and very heavy.—Potash
produces a salt which crystallizes in long white brilliant plates,
having a disagreeable metallic taste, not affecting test-paper, dis-
solving completely in eight parts of boiling water, and detonating
powerfully when heated or struck. It contains 85:08 of acid, and
14-92 of base.—Soda has always produced a salt in small rounded
plates, brown and brilliant ; they are lighter and more soluble than
the preceding, but otherwise resemble it. ‘They contain 88-66 of
acid, and 11-34 of base.—Ammonia with fulminating silver leaves
no residuum. Berthollet’s compound being formed at the same time
with the other. On cooling, a large quantity of granular crystals
are obtained, which are difficultly soluble, and have a strong me-
tallic taste. They detonate even in the liquid when touched by a
glass rod, but fortunately if excess of alkali be present the deto-
nation does not extend to the neighbouring portions.

2. On the unequal Dilatation of a Crystal in different directions,
by heat.—On measuring the mutual inclinations of the planes of a
crystal of carbonate of lime at different temperatures, M. Mits-
cherlich observed that they varied sensibly with the temperature,
the variation sometimes amounting to 8'.5 from 32° to 212. Fahr.
When the temperature rose, the obtuse diedral angles diminished,
or in other words the short axis of the rhomboid expanded more
than the other diagonals, so that its form approached to that of the
cube. M. Mitscherlich concluded, therefore, that the double re-
fraction of the crystal would at the same time diminish; a result
confirmed by an experiment which he afterwards made with M.
Fresnel in the manner adopted by that philosopher in 1817, to
render more sensible the changes in the tints of plates of sulphate
of lime. M. Fresnel had then observed, that elevation of tempe-
rature sensibly diminished the double refraction of sulphate of
lime ; and according to the recent experiments of the two philoso-
phers the same effect is produced, though in a much less degree,
on rock crystal. This experiment, however, requires repetition.

It appears, therefore, that generally an uniform elevation of tem-
perature in acrystal diminishes its double refraction. M. Mits-
cherlich thinks that heat ought always to separate the molucules of
a crystal farthest apart in that direction in which they are most
contiguous.—Ann. de Chim. xxv. 109.

3. Difference of crystalline Forms of the same Substance.—M.
Mitscherlich, who first observed the remarkable fact that a body
may affect two different crystalline forms, has, in a memoir on this

158 Miscellaneous Intelligence.

suhject, quoted sulphur as an instance. Natural crystals of sul-
phur are furnished by some calcareous strata, and by volcanoes.
Artificial crystals may be obtained either by evaporating a solution
of it in carburet of sulphur, or by fusion of the sulphur and slow
cooling. On fusing native sulphur, it gives the same crystals as
common sulphur. The primitive form of the crystals of sulphur,
either natural, or obtained as above by evaporation, is an octoédron,
with a rhombic base; but the primitive form of the crystals ob-
tained by fusion, is an oblique prism, with a rhombic base.— Anz.
de Chimie, xxiv. 264.

4. Supposed Effect of Magnetism on Crystallization. — The follow-
ing is an experiment first made by Professcr Maschmann, of Chris+
tiana, and confirmed by Professor Hanstein, of the same city; we
should nct have noticed it but for these names. A glass tube is to
be bent into a syphon, and placed with the curve downwards, and
inthe bend is to be placed a small portion of mercury, not suffi-
cient to close the connexion between the two legs; a solution of
nitrate of silver is then to be introduced until it rises in both limbs
of the tube. The precipitation of the mercury in the form of
an arbor Diana will then take place, slowly only;when the syphon
is placed in a plane perpendicular to the magnetic meridian;
but if it be placed in a plane coinciding with the magnetic me-
ridian, the action is rapid, and the crystallization particularly
beautiful, taking place principally in that branch of the syphon
towards the north. If the syphon be placed in a plane perpendicular
to the magnetic meridian, and a strong magnet be brought near it,
the precipitation will recommence in a short time, and be most
copious in the branch of the syphon nearest to the south pole of the
magnet.

4. On Thermo-magnetism.—The following account of results on
the magnetism of a single piece of metal developed by heat, is
abstracted from a paper by Dr. J. d’Yelin, or rather from an
account of that paper in the Bibliotheque Universelle. The re-
sults, if confirmed by further experieuce, are very highly impor-
tant to the theory of magnetism.

In repeating the experiment of Seebeck, M. Yelin made use of
platina, gold, silver, iron, copper, brass, zinc, tin, lead, antimony,
bismuth, and arsenic. The result of his observations was that
‘* the effect of Seebeck’s circuit should not be considered as a de-
terminate function of power possessed by the heterogeneous metals
of developing electricity by contact, and of their various conduct-
ing powers as to heat; and that therefore, conclusions cannot be
drawn from these properties,” as is proved by the following facts :
' 1. Silver and zine give by contact an electricity stronger than
silver and antimony; but a circuit formed of the two latter metals

Chemical Science. 159

has much greater power than one composed of the former, which
is very feeble. The case is the same with the two sets, copper
and zinc, and copper and bismuth. ©

2. Brass, copper, and lead, according to Bockmann, have a
conducting power as to heat of 344, 346, and 850; nevertheless,
acircuit of brass and copper is sensibly stronger in its action than
a circuit of lead and copper.

3. Finally, silver in contact with antimony is electrized nega-
tively, in contact with zinc it is still more powerfully so; but

- other circumstances being equal, a circuit of antimony and silver
has seven times the power over a magnetic needle that a circle of
zine and silver has. Antimony is positive when opposed to pla-
tina, gold, or silver, and negative when opposed to copper, tin,
lead, or zinc; but whichever of those metals be formed into a
circuit with antimony, the same effect is obtained, the same pole
of the needle always being urged to the same side. Bismuth and
antimony are both positive when in contact with platina, gold, and
silver, but all other things being equal, as the dimensions of the
metal, the soldering, the temperature and arrangement, a circuit
ormed of bismuth and one of the last named metals, turns the

ole of the needle 14°, 51°, or 45° to the east, whilst if antimony be
substituted for the bismuth, the pole is thrown 18°, 25°, or 30° to
the west.

Being induced to consider the rupture of the equilibrium of
temperature as the principal cause of the electro-magnetic action
of Seebeck’s circle, M. d’Yelin endeavoured to obtain similar
effects with a single piece of metal, and having obtained very de-
cided effects, he has given to this class of phenomena the name of
thermo-magnetism. ‘That very feeble magnetic action might be
observed, very delicate needles were used; they were of great
tenuity and suspended by a single spider’s thread.

If a band of any single metal be formed into a circuit of any
figure, by riveting one of its ends near the other, and the projecting
end be heated by a flame, whilst the circuit is plunged in cold
water, this band will become electro-magnetic, and its properties
may be easily ascertained. The experiment was made with zine,
bismuth, brass, tin, lead, and copper, and M. d’ Yelin infers that
“ all metallic bodies acquire electro-magnetic properties when their
various parts are unequally heated, and that the action is stronger
as the difference of temperature is greater.”

This fundamental experiment being established, the following
are the principal results obtained by the author:—

I, The metals, in reference to their thermo-magnetic properties,

may be ranged as follows, commencing with those which possess
them in the highest degree, bismuth, antimony, zinc, silver, pla-
tina, copper, brass, gold, tin, lead.

II. A metal acts differently on the needle according as the hot or

160 Miscellaneous Intelligence.

the cold part of it be placed under the needle. The following experi-
ments were made with cast bars six or seven inches long, one inch
in thickness, and formed either as cylinders, or as prisms with three,
four, or six sides; solid and hollow balls were also employed :—
1. If one extremity of a bar of bismuth be heated, the bar be
placed in the direction of the magnetic needle, with its cold end to
the north, and the hot end be brought under the needle, the point
of the needle will turn towards the east. 2. If the direction of the
bar being preserved, it be moved towards the south until its cold
end is under the needle, the needle will turn towards the west.
3. The inverse effects are obtained when the hot end of the bar is
towards the north. 4. When the bar is heated in the middle, and
the ends preserved cold, the same effects are obtained for each half
of the bar. 5. The magnetic effects are sensible when one part of
the bar is heated merely by the hand and the other cooled by snow.

III. The magnetic action of metals unequally heated depends on
the form given them in casting, and in this it differs from the
action of Qérsted’s connecting wire. 1. If an equilateral tri-
angular prism of bismuth be used as in the former experiments (1),
and its faces be turned upwards successively, one of its faces will
make the needle deviate to the east, the next face (that towards
the east) brought into the place of the first, will make the needle
deviate to the west; the third face has so uncertain an effect that it
may be considered as null. 2. If a square or four-sided prism of
bismuth, antimony, or zinc, be used in a similar manner, it will be
found that two contiguous faces when turned upwards will make
the needle move eastward, whilst the other two faces will move it
westward, so that the prism may be considered as composed of two
triangular prisms of which the un-magnetic faces are in contact.
3. With a regular hexagonal prism three of the faces move the

“needle eastward, and three move it westward. 4. Cylinders pre-
sent peculiar effects; a cylinder of bismuth had been thrown with
its mould into cold water immediately after being cast, another was
suffered to cool slowly ; when these cylinders were used in place of
the prisms, the ends which were uppermost in the moulds being
placed under the needle, one part of the curved surface urged the
needle to the east, and the other part to the west; these parts were
equal in the first cylinder, but unequal in the second. When the
other extremities of the cylinders were placed under the needle,
then the curved surface of the first cylinder presented four nearly
equal portions which successively turned the needle to the east and
west: the second bar presented six similar portions.

The differences remarked between the extremities of the cylin-
der, and also between the cylinders themselves, when cooled slow-
ly or rapidly, induces M. d’ Yelin to conclude there is some rela-
tion between the crystallization of metals and their magnetic pro-
perties.— Bibliotheque Universelle, xxiv. 253.

Chemical Science. _ 161

’ 5. Electromagnetic Multipliers —Dr. Kaerntz has lately been oc-
cupied in proving experimentally the amount of the advantage ob-
tained in electromagnetic multipliers, by each additional circumvo-
lution of the wire. His motor was a zinc plate about eight inches
long and four inches wide, the copper opposing both sides was
consequently double that'size. The fluid conductor was a solu-
tion of muriate of ammonia in spring water, with the addition of
one hundredth of sulphuric acid. The connecting wire was cop-
per harpsichord wire, covered with silk thread, and the same
length was used in every experiment. By connecting the plates
with the wire before immersion, by immersing slowly and by other
expedients, any important variation in the intensity or quantity of
action was avoided.

In this way it was found that the quantity of power of the in-
strument over the needle, was exactly in proportion to the number
of convolutions, six convolutions giving six times the power of one
convolution; and by experiments, when the forces of the instru-
ment and of the earth’s magnetism were arranged in different
ways, this result was confirmed. Such an instrument is therefore
wore correctly called a multiplier than a condenser.—Phil. Mag.

xii, 441,

6. Plate Electrical Machines.—A variation in the construction
of plate electrical machines has been devised and practised -by
M. Metzger of Siblingen in Schaffhouse, which would seem to be
areal improvement. Considering that the effect desired in using
the machine was first highly to excite the glass, and then to col-
lect the electricity from it, M. Metzger concluded that the dis-
tance between the rubber and the points of the conductor in ma-
chines of the common construction was injurious in its effect, not
only by causing the dispersion in part of the electricity excited,
but by uselessly wasting the exciting surface. Plates were -
therefore mounted in a very compact and perfect manner, with
three pairs of rubbers placed at equal distances from each other ;
the conductor also had three arms furnished with points a little in
advance of each pair of rubbers, to collect the electricity in the
usual manner. ‘The rubbers were not attached to a surrounding
frame, but to brass arms, which proceeding froma socket through
which the axis passes, diverged at equal distances from each other
towards the periphery of the plate. The machine has a very com-
pact and neat appearance, and its various smaller parts are con-
trived with much judgment.

In some comparative experiments made with a plate twenty-two
inches in diameter, the superiority of three pair of cushions over
two pair was very manifest. In the following table the first
column expresses the length in inches of the rubbers; the second
the length of the spark when two pair of rubbers were used, and the

Vor, XVII. M

162 Miscellaneous Intelligence.

third the length of the spark when three pair of rubbers were on
the machine. ;

6inches. . .12inches. . . 18 inches.
Tc pessetl diana cath adie ous na satin, Le
ah. maptae a SAE dynamite v9
SR er aA |: RE EERR Tele i+ <n
De tees ol en Se te ag

Bib. Univ. xxiv. 187.

7. Improvement of the Leyden Jar.—M. Metzger has also varied
the construction of Leyden jars, so as to augment their capa-
city without increasing their apparent volume. For this purpose
having two jars of proper dimensions, he simply places one within
the other, so that they shall apply pretty correctly, and thus have a
capacity of charge nearly proportional to, the whole surface of
coating, without increasing the volume of the whole beyond that of
the larger jar. Jars made slightly conical would answer well for
this purpose.—Brb. Univ, 191.

8. Electricity on Separation of Parls.—In the water-proof cloths
manufactured by M. Mackintosh of Glasgow, where two pieces
are cemented together by caoutchouc dissolved in coal tar oil, the
adhesion is such that when the two are torn asunder in the dark,
there is a bright flash of electric light, similar to that produced by
separating plates of mica, by breaking Rupert’s drops, or by
breaking barley-sugar, or sugar-candy. Upon trying this experi-
ment with different substances, it was found that flashes of light
were distinctly produced, by tearing quickly a piece of cotton
cloth.—£din, Jour. x. 185.

9. Electric Light —Having a metallic wire covered with silk,
form it into a close flat spiral, taking care that the revolutions
touch each other. Their number may be arbitrary, more than
twenty-four have not been used. The properties of this spiral
when it forms part of the voltaic circuit are well known, but pass
through it a charge of common electricity, such as may be taken by
two square feet of coated surface, moderately charged, and a vivid
light, something resembling that of an artificial fire-work, will occur,
originating from the centre of the spires. It may be seen very
distinctly without darkening the chamber where the experiment is
made.

M. Leopold de Nobili, who describes this experiment, considers
the phenomenon as perfectly new. If the wire be folded backwards
and forwards, so as to form a rectangular surface, then the electric
discharge only produces a faint light at each corner, and this he
considers as the light produced by the escape of the electricity into

Chemical Science. — 163

the atmosphere ; but the light from the spiral is said to be so vivid
and distinct, that once seen its dissimilarity from the former must
be instantly evident. He has, therefore, called it electromagnetic
light, because of its relation to the magnetic state of the spiral,
thinks that it might be made continuous if a sufficiently powerful
yoltaic battery were used, and has little doubt but that the aurora
borealis is such a light elicited by the magnetic state of the earth,
—Bib. Univ. xxy. 38.

10. Connexion of Phosphorescence with Electricity.—The sul-
phate of quina was shewn by M. Callaud d’Annecy some time
since to become highly phosphorescent when rubbed at a tempe-
rature of 212°. MM. Dumas and Pelletier have ascertained
that it becomes highly negatively electrical when rubbed on
woollen cloth, and hence were led to the verification of a suspicion
they had long entertained that phosphorescence was an electrical
phenomenon. About two or three ounces of sulphate of quina
were introduced into a glass flask, and heated for half an hour in
a water bath at 2120 F., it then by friction gave out a suffi-
ciently intense light. ‘The flask was closed by a cork, through
which passed a wire pointed at the inner extremity, and termi-
nated by a ball at the external end; on approaching this ball, two
or three times to the knob of a voltaic electrometer furnished with
its condenser, having taken care to shake the flask before each
contact, the leaves became so electrical as to diverge as much
as the instrument would admit of, the electricity being constantly
positive.

The sulphate of cinchona, which is phosphorescent like the
sulphate of quina, though less so, also became electrical in the
same manner. Its electricity, though of the same kind, was not
so strong as that of the preparation of quina.—Ann. de Chim.
xxiy. 171.

11. Phosphorescence of Acetate of Lime.—Dissolve any quantity
of acetate of lime in water, and place it on a sand-heat in a Wedge-
‘wood ware dish, evaporate to dryness without disturbing it. When
quite dry, let the bulb of a thermometer be rested on the bottom
of the dish, and when the temperature has attained 250° F., the
lime will be found to adhere very firmly. If light be now ex-
eluded, and the acetate be strongly rubbed with a stiff spatula, it
nd become highly luminous. Mr. N. Mills. —Ann. Phil. N.S.
vii. 235.

+12. Preparation of Sulphurous Acid Gas.—M. Berthier has

shewn that this gas may be obtained very pure and abundantly,

heating a mixture of twelve or fourteen parts of sublimed sul-

phur, and a hundred parts of peroxide of manganese in a glass
M 2

164 Miscellaneous Intelligence.

retort. The residue in the retort is not a sulphuret of manganese,
but a protoxide of manganese mixed with a little sulphate of
manganese, and sometimes a little sulphur—Ann. de Chim.
xxiv. 275.

13. Preparation of Sulphuretted Hydrogen.—The experimental
researches of M. P. Berthier, into the production and composition
of certain metallic sulphurets, have been referred to at length,
vol. xy. p. 148. Since then another paper has appeared by the
same chemist, and relating to the same subject, from which we
extract the following matter. In the preparation of sulphuretted
hydrogen, it is usual to act on sulphuret of iron by diluted
sulphuric acid, or sulphuret of antimony by strong muriatic
acid ; but, for various reasons, M. Berthier recommends the follow=
ing compounds of sulphur as better. Powdered common iron
pyrites is to be mixed with half its weight of dry carbonate of
soda, and heated red-hot in a crucible; a fluid sulphuret of iron
and sodium is obtained, which may be poured out ona stone to
cool, and is then a homogeneous deep yellow mass, possessing a
lamellar fracture. It absorbs much water, forming with it a black
paste, which when acted on by sulphuric or muriatic acid instantly
yields abundance of sulphuretted hydrogen; leaving a black sul-
phuret of iron, which by the application of acid and heat, will yield
a second portion of the gas.

Peroxide of manganese mixed with sulphur or charcoal, and
heated to bright redness, becomes a protoxide, which treated with
sulphuric acid forms a sulphate. This sulphate powdered, mixed
with one-sixth of powdered charcoal, and heated to whiteness in
a closed crucible, yields a pulverulent sulphuret of manganese,
which when acted on by a mixture of one part sulphuric acid, and
one part water, gives abundance of sulphuretted hydrogen, and
becomes sulphate of manganese again: one hundred parts of the
sulphuret yields 384 parts of sulphuretted hydrogen.

Of all the sulphurets that of calcium appears to be the most
proper for this purpose. It produces abundance of the gas, a
hundred parts producing 46.8 of sulphuretted hydrogen ; the resi-
due on the action of muriatic acid is entirely soluble, and therefore
admits of perfect and free action without the application of heat;
and it may be obtained in the greatest abundance. Sulphate of
lime is to be reduced to an impalpable powder, and then mixed
with powdered charcoal in the proportion of 0.15 of the latter, if
the sulphate be a hydrate, but if an hydrous 0.20 of charcoal will
be necessary. The mixture is to be put into crucibles, and heated to
whiteness for an hour or two in a wind furnace. The sulphuret
does not act on the crucible, and is obtained in a pulverulent state.
If the sulphuret be required in great quantity it may be prepared
by mixing the sulphate of lime and charcoal with a sufficient quan-

Chemical Science. 165

tity of plaster of Paris, moistening and moulding the whole into
bricks, which may be burnt like bricks of clay.—Ann. de Chim.
xxiv. 271.

14. Preparation of Saturated Hydro-sulphuret of Potash or
Soda.—The following is M. Berthier’s process: mix ten sulphate of
potash, ten sulphate of baryta, and five powdered charcoal, or
eight dry sulphate of soda, ten sulphate of baryta and five pow=
dered charcoal, and heat them to whiteness in a crucible. Double
sulphurets are obtained, which are greyish, half-fused, and easily
separated from the crucible; they contain each an atom of the
composing sulphurets. Pulverize and introduce them gradually
into a flask three-fourths filled with warm water, close it and fre-
quently agitate it; when saturated, the water will contain an atom
of the sub-hydrosulphuret of alkali and an atom of sub-hydro-
sulphuret of baryta. Diluted sulphuric acid is then carefully
added to the solution in the flask, by small portions at a time, agi-
tating éach time and preserving the flask well closed. In this
way the baryta is precipitated, and its sulphureted hydrogen goes
to the alkali; when all the earth has fallen, the fluid is left to be-
come clear, is decanted and tested by solution of salts of lime or
magnesia. If a precipitate occurs, a fresh portion of hydrosul-
phuret of baryta must be added to the liquor and precipitated by
sulpburic acid. With a little care, a neutral hydrosulphuret of the
alkali is obtained, which contains neither baryta or sulphuric acid,
but of the two it is better to have the acid in excess.—Ann. de
Chim. xxiv. 279.

15. Preparation of Kermes Mineral.—According to M, Fabroni, a
much finer kermes mineral is obtained by using tartar in place of the
alkali employed in the usual process. Three or four parts of tartar
should be mixed with one part of powdered sulphuret of antimony,
and heated red in a crucible until the cessation of fumes indicates
that the tartar is all decomposed ; the mass is then to be dissolved
in hot water, filtered and left to cool, when abundance of fine
kermes will be deposited, of a very deep colour. ‘The abundance
of kermes thus obtained does not at all interfere with the quantity
and beauty of the golden sulphuret, afterwards obtained by the ad-
dition of acid to the mother liquor.—Ann. de Chim. xxv. 7.

16. Action of Sulphur on Iron.—Col. A. Evans has remarked,
that although sulphur has so strong an action on heated wrought
iron as immediately to form holes in it, yet it does not at all affect
grey castiron, A plate of wrought iron, 63 of an inch in thick-
ness, heated to whiteness, and held against a roll of sulphur ~§; of
an inch in diameter, was in fourteen seconds pierced through with

perfectly cylindrical hole. Another bar about two inches in

166 Miscellaneous Intelligence.

thickness was pierced by the same means in fifteen seconds. Good
steel was pierced even more rapidly than the iron, but a piece of
grey cast iron, well scaled and heated till nearly in fusion, was not
at all affected by the application of sulphur to its surface, not even
a mark being left. A crucible was made of this cast iron, and
some iron and sulphur put into it; on applying heat the iron and
sulphur soon fused together, but the cast iron underwent no
change.—Ann. de Chim. xxv. 107.

17. Economical Preparation of pure Oxide of Nickel, by M. Ber-
thier.—Speiss, or impure nickel, is to be reduced to fine powder
and roasted till it gives off no further vapours of arsenic, the heat
being at first moderate to prevent fusion, and then increased.
Metallic iron in the state of filings or nails is to be added in a
quantity which ought previously to be determined, and the whole
dissolved in boiling nitro-muriatic acid, so much nitric acid
being used that no protoxide of iron remain in the solution; eya-
porate to dryness and re-dissolve in water, when a large quantity of
arseniate of iron will be left. Add to the solutions successive
portions of carbonate of soda until a greenish precipitate appears,
at which time ali the arsenic and iron will be separated, and part of
the copper; the rest of the copper may be separated by sulphuretted
hydrogen, and the clear solution thus obtained, when boiled with
sub-carbonate of soda, yields the carbonate of nickel.

Thus obtained, the carbonate of nickel contains a little cobalt;
to separate the latter, the precipitate as obtained above by boiling
with sub-carbonate of soda, is to be well washed and diffused
whilst moist in water, and~a current of chlorine passed into it
until in excess: the excess of chlorine is to be allowed to dissi-
pate and the solution filtered ; it now contains not the smallest trace
of cobalt, that remaining as a hydrated peroxide, with a certain
portion of nickel in the same state. Ifin the mixed carbonate of
nickel and cobalt, the latter is in excess; the residue, after the
action of the chlorine, is pure hydrate of cobalt, and the solution
contains the nickel with a small quantity of cobalt.—Ann. de Chim.
xxv. 95. . :

18. White Copper.—According to M. Keferstein, a metallic com-
position resembling silver has been employed under the name of
white copper, for a long time at Suhl, in ornamenting fire-arms.
M. Brandes, by analysis, found it to be an alloy of copper and
nickel. MM. Keferstein and Muller have recently sought out the
origin of this substance, and have ascertained that it is found in
‘the scoria of some ancient copper-works, formerly attached to
mines now abandoned. ‘The white copper, which had formerly
‘been rejected as useless, is now obtained by fusion, for the purpose
above stated.—Ann, de Chim, xxiv, 234.

Chemical Sctence. 167

19. Prussian Blue.—Mr. Badnall, of Leek, has taken out a pa-
tent for improvements in dyeing with Prussian blue. The improve-
ment consists in preparing the Prussian blue, by mixing it in fine pow-
‘der with strong muriatic acid, and stirring it until the whole becomes
a smooth homogeneous mass of a semi-gelatinous consistence. We
notice it here merely to remark on the circumstance that an agent
in which Prussian blue is insoluble, should be found useful in ena-'
bling it to combine with silk, cotton, wool, §c. The pure ferro-
prussiate of iron is soluble in water, but the addition of a small
portion of muriatic acid immediately precipitates it; wash away
the acid by pure water, and the pigment becomes soluble again ;
re-acidify, and it re-precipitates.

20. Crystallization of the Sub-carbonate of Potash.—ll Dot..M. Fa-
broni describes the following process for the crystallization of this
salt, Make a solution of pearlash in water, and evaporate it until of
specific gravity 1.57.. Allow it to cool, when all extraneous salts will
be deposited; separate the fluid and again concentrate it until of spe-
cific grav. above 1.6. The fluid will now be of a light green colour,
and strong alkaline odour; place it in deep vessels, as glass jars for
instance, and the sub-carbonate will soon crystallize in long rhom-
boidal white lamine, situated vertically and parallel to each other;
one extremity will touch the bottom of the vessel, and the other be
attached to a saline crust on the surface of the liquid. When cold,
the mother liquor will be found of specific grav. 1.6, but if further
concentrated and again cooled, more crystals will be obtained ; and
this may be continued until the whole has been crystallized.—Gior.
di Fisica, vi. 451.

21. Composition of Ancient Ruby Glass.—Mr. Cooper, on ana-
lyzing a portion of this glass, sent to him by Mr.C. Muss, found
it to contain silex, oxides of copper, iron, and silver, and lime. He
considers the oxides of copper and silver as the colouring matter,
but from the coloured portion being a film not more than 3},5 of an
inch in thickness, upon the surface of the glass, it was impossible
to ascertain their proportions. Iron existed abundantly in the un-
coloured portion of the glass. Mr. Cooper thinks the alkali used
as a flux for the siliceous matter is soda.—Ann. Phil. N.5. vii. 106.

22. Detection of Arsenic in cases of Poisoning.—Mr. Phillips, in
a very excellent practical paper on the methods of employing the
various tests proposed for the detecting the presence of arsenic,
has very much facilitated their use in certain cases, by pointing out
that where the arsenic is mingled with a complicated mixture of
animal and other substances, as when its presence is to be ascer-
tained in fluids from the stomach, animal charcoal may be very
advantageously employed as a preparatory agent. Some coloured

168 Miscellaneous Intelligence.

liquor arsenicalis on being boiled for a few minutes with ivory black
was rendered so colourless that any of the tests for arsenic could
be readily applied. The experiment was repeated, substituting for
the colouring liquor, port wine, gravy-soup, and a strong infusion
of onions, and in all these cases a solution was obtained sufh-
ciently colourless for the application of the most delicate tests.
This agent is not liable to any mistake from the presence of phos-
phates, for water or wine boiled in it alone separated nothing ex-
cept, in one or two cases, a small portion of a muriate; to avoid
the interference of this substance, the ivory black may be washed
-with boiling distilled water until the washings do not affect nitrate
of silver; but good ivory black does not require this treatment.

With regard also to the application of sulphate of copper as a
test of arsenic, Mr. Phillips recommends a precaution which has
not heretofore been thought of. Sulphate of copper yields a green
precipitate when added to potash, white arsenic being present; but
if the sulphate contains any peroxide of iron,.it may yield a green
precipitate with the alkali, the arsenic not being present. Mr. P. has
remarked that the arsenic may be added after as well as before the
precipitate is formed, for the blue precipitate occasioned by the
potash in pure sulphate of copper becomes green when the white
arsenic is added. Add solution of potash first, therefore, to the
sulphate of copper, and obtain the fine blue precipitate; to a part
of this add the suspected solution, and if arsenious acid be pre-
sent it will convert the blue precipitate into a green one. — Ann. Phil.
N. S. vii. 30.

In reference to the reduction of arsenic to the metallic state, as
a test of its presence, Dr. Trail thinks the general opinion of the
large quantity required is unfounded, and easily succeeds in ob-
taining this evidence from 54; of a grain of white arsenic. The
tube is to be 24 inches long, 0. 4 inch. wide, and closed at one
end. The substance thought to be arsenic should be mixed with
thrice its weight of black flux, or sub-carb. soda mixed with char-
coal powder, introduced into the tube, and a little charcoal powder
put over it; the upper part of the tube must be cleaned, and the
-mouth closed by a piece of paper. The flame ofa spirit-lamp will
in about two minutes produce a shining metallic crust on the upper
side of the tube; when cold shake out the loose materials, scrape
off the metallic crust, which will afford sufficient for six different
portions, each of which when projected on a dull red-hot poker will
give a white smoke and alliaceous odour. A clean knife held in
the smoke will always condense a portion of white powder.—Ann,
Phil. vii. 132.

23. On the Detection of Acetate Morphia in cases of Poisoning,
by M. J. L. Lassaigne.—The following are the processes recom-
mended. If the acetate of morphia be suspected in a liquid, it is

Chemical Science. 169

to be evaporated by a moderate heat, and the residue digested in
-alcohol, which will dissolve the acetate as well as ozmazome and
- some salts. The alcoholic solution evaporated, and the residue dis-
‘solved in water, will cause the separation of a portion of fatty
matter. The Jast solution is to be evaporated spontaneously, and
if it contains acetate of morphia, that substance will crystallize in
diverging needles of a yellow colour, and known by, 1, their
‘bitter taste; 2, their decomposition by ammonia; 3, the li-
beration of acetic acid by strong sulphuric acid; 4, the red
colour developed by nitric acid. Ifthe salt be in such small
quantity that the ozmazome prevents its crystallization, nitric acid
will detect it by the colour produced.

If it is suspected to exist in a solid mixture or substance, it is
to be boiled with water for about ten minutes, and then treated as
above. If the accompanying substances are alkaline, a small

quantity of acetic acid must be added, to form an acetate with the
morphia.

By these methods M. Lassaigne has detected the acetate of

morphia ; 1, in the substances vomited by animals to which it
had been given; 2, in the stomach of a cat who died on taking
five grains of it; 3, in the liquid from the thorax of a dog
which died ten minutes after the injection of fourteen grains of the
substance; 4, in the small intestines of a cat which died ten
hours after the injection of eighteen grains of the substance into
that canal ; 5, in the duodenum of a dog which died four hours
and a half after the injection of eighteen grains into that part.
_ It was found also in the blood from the jugular vein of a horse,
opposite to that by which thirty grains of the acetate had been in-
jected ten minutes before ; but five hours after the injection none
could ke found, indicating that where the animal could support the
poison it was gradually destroyed or expelled. A grain of the
‘salt mixed with six ounces and a half of ox blood, was easily
found again after several hours.

Lest the orange colour produced by nitric acid should be due
to the presence of an animal substance, M. Lassaigne endeavoured

‘to avoid the presence of any such matter, and found the following
process perfect in this respect. A solution of sub-acetate of lead
is added to the aqueous solution of the alcoholic extract sus-
pected to contain acetate of morphia, all the colouring and azoted
matters are immediately precipitated, and there remains in solu-
tion only certain salts with the acetate of morphia, and a slight
excess of acetate of lead, which latter may be decomposed by a
few bubbles of sulphuretted hydrogen. The solution should then
be evaporated in vacuo over sulphuric acid, and if it contains
acetate of morphia, that substance will soon crystallize, its base
may be separated, and the colour by nitric acid is no longer
equivocal.

170 Miscellaneous Intelligence.

The conclusions appended to this mémoire, are, 1, thatit i s
possible in many cases of poisoning by acetate of morphia, to dis-
cover sensible traces of this vegetable poison; 2, that the sub-
stances vomited shortly after taking the poison into the stomach
contain ponderable quantities of it; 3, that it is always in
those viscera into which it has been introduced, that its remains
may be detected; 4, that all attempts as yet made to discover
it in the blood of the dead animals have been fruitless.—Ann. de
Chim. xxv. 102.

24. Test for Morphium—M. Dublane a druggist of Paris, states
that he finds the tincture of nutgalls a very. sensible test of the
presence of morphium in fluids, whether it exist free or in combi-
nation with acetic or sulphuric acid.— Ann. de Chim. xxv. 92.

25. Process for obtaining Strychnia, by M. Ferrarti.—Boil three
pounds of bruised nux vomica for two hours in thirty pints of
water acidified by six ounces of muriatic acid, and pass the
liquid through a cloth or sieve: the residue should be thrice
boiled again for the same time, and in equal quantities of acid and
water. To the united cold infusions add lime slowly whilst mix-
ing, until in considerable excess; after two or three days decant
the liquid, collect the paste on a filter, dry and powder it. The
decanted liquor should be rather more than neutralized by muri-
atic acid, evaporated until reduced to a few pounds, when cold
precipitated by lime, allowed to stand, decanted, and the residue
when dry, powdered and added to the former.

Sulphuric acid may be substituted for muriatic acid in the pro-
cess, but the three pounds of nux vomica will require only three
ounces of this acid in twenty pints of water, and the boiling
should continue one hour only. Afterwards, the liquid rendered
acid is to be concentrated until like syrup, being agitated during
the evaporation if any deposit appears. ‘To the cold liquor pow-
dered lime is to be added, and the process goes on as before.

The mixed precipitate of lime and strychnia obtained by either of
the above methods is to be heated in a water-bath two or three times,
with alcohol of specific grav. 0.832, until all the bitter principle is
extracted. The united fluids are to be distilled, and this operation
finished ; there will remain a yellow turbid bitter alkaline fluid,
which is to be decanted off and reserved, and beneath it the
strychnia soiled by a yellow colouring matter, which will harden
upon cooling. This mixture treated with cold alcohol of specific
gravity .915 will leave pure strychnia.—Gvor. de Fisica.

26. Volatility of Salts of Strychnia.—Il Sig. Ferrari bas remarked
that solutions of salts of strychnia slightly acid when exposed
to a heat of 212°, so as to be concentrated, then become volatile
and the salt evaporates. This property has been remarked in the sul-

Chemical Science. — 171

phate, nitrate, muriate, and acetate, and is believed to belong to
all the salts. It has been remarked by M. Collaud and others,
that the sulphate of quina is also volatile, and M. Ferrari, on re-
peating the experiments with the muriate and nitrate of quina,
found it also to happen with them. The solutions on being heated
in a tinned copper vessel, gave out vapours which when breathed,
were found to be highly bitter, The salts vary in the extent of
this property, and it is also affected by the degree of acidity, and
of concentration of the solution.—Gior. de Fisica, vi. 460.

_. 27. Acid Tartaro-Sulphate of Potash.—Il Sig. M. Fabroni says
that sulphuric acid being boiled with thrice its weight of water,
and cream of tartar in excess, gives a fluid, which after having
been evaporated, cooled, and allowed to deposit undecomposed
tartar, sulphate of potash, &c., will not furnish any other deposit,
and resembles oil in its appearance. When further evaporated to
the consistence of syrup, and again cooled, it solidified in a mass
composed of imperfect prismatic crystals, and which when dry,
had something of the appearance of camphor. It dissolves rapidly
in water, but in alcohol yields its tartaric acid, and acid sulphate
of potash is left. On analysis it gave seventy-two tartaric acid,
and twenty-eight acid sulphate of potash. M. Fabroni thinks that
for many uses this salt may be a cheap and effectual substitute for
tartaric acid. He considers it as analogous in its nature to the
compound of tartar and boracic acid. Gvor. de Fisica, vi. 452.

28. Pyroligneous Ether, or Pyroxilic Spirit.—A brief description
is given* at p. 436, vol. xiv, of this Journal, of a substance ob-
tained by Mr. P. Taylor, first in 1812, and at various times since
then, from the distillation of wood. M. Taylor called it pyrolig-
neous ether. Latterly this substance has been re-examined with
‘great care, by MM. Macaire and Marcet, of Geneva, who have
called it pyroxilic spirit, in their paper upon it, published in the
Bibliotheque Universelle. The following is a brief account of their
observations. The fluid is transparent, colourless, of a strong
ethereal odour slightly resembling that of ants. Its taste is hot
and strong, leaving an impression on the tongue like that of essence
of mint: its specific gravity .828. It boils at about 150° F. Its
slightly acid properties appear to be due to a little acetic acid.
‘It burns away entirely with a perfectly blue flame. Alcohol
dissolves it in all proportions, but water separates it again. With
water only, it forms a sort of emulsion, which is of considerable
permanence. It does not dissolve in oil of turpentine. It dis-
solves camphor, but not oil of olives either hot or cold. It also
dissolves pure potash.

Heated with its volume of sulphuric acid, it distils over un~

cs »* Fromthe Phil, Mag, Lx. 315,

172 Miscellaneous Intelligence.

changed; heated with thrice its volume of sulphuric acid, it
blackens, swells, and liberates a small quantity of inflammable
gas, which burns with a pale flame, is not condensed by chlorine,
and appears to be.a mixture of proto-carburetted hydrogen
and hydrogen. When distilled with its volume of nitric acid nitrous
vapours arise, and an ethereal liquid distils over, which when
distilled from oxide of lead, reddens litmus, has an agreeable
odour, burns with a strong greyish flame, dissolves in water and
alcohol, communicating a sweet mild taste, and in all its pro-
perties quite unlike nitric ether. A current of nitrous gas passed
into a portion of the pyroligneous fluid effected no change in it.
Muriatic acid produced no effect upon it.

A current of chlorine passed into the fluid, made it of a deep
yellow colour, but continuing the current a few minutes, the colour
on asudden disappeared, six parts of the fluid had thus increased
to six parts and a half, of a colourless transparent liquid, fuming
by ammonia, having a poignant odour, and exciting tears. It
burnt with a blue flame, producing abundant fumes of muriatic
acid, and an odour resembling horseradish. When distilled from
litharge, it passed over less acid, but otherwise unchanged. _ Its
specific gravity was 0.889; it was soluble in water and alcohol,
communicating a strong taste of horseradish. It precipitated ni-
trate of silver, and became more acid by exposure to air and
light. This compound as well as that produced by the action of
nitric acid, appears to be an ether, having particular properties ;
and these ethers prove that the pyroligneous fluid is in its relation
to acids analogous to alcohol.

MM. Macaire and Marcet then prepared some of the pyro-
acetic spirit described by Chenevix, and instituted comparative ex-
periments on it, and Taylor’s fluid. The pyroacetic spirit is
lighter than the pyroligneous fluid, being according to Chenevix of
specific gravity 0.786, Its taste and smell are different. It burns
with a strong white flame, and is quite soluble in oil of turpen-
tine. Sulphuric acid does not trouble or blacken it, but produces
a fine yellow red colour, and the fluid remains transparent until
heated. Distilled with muriatic acid, a volatile fluid passes, and
a black substance remains ; distilled on potash the fluid loses its
acid odour, and the residue smells like tar. Chlorine passed into
the pyroacetic spirit, rendered it of a slight yellow colour. The
fluid resulting had a strong suffocating smell, resembling that of
the substance obtained by treating the pyroligneous fluid in the
same way, but after a time it separated into two portions, the
one thick, oily, heavy, and transparent, the other light, and
slightly opalescent. The latter burnt with a light blue flame,
being an acid residue. It is soluble in water, communicating a
hot taste to it, but not like horseradish. The oily fluid burnt

‘Chemical Sciences 173

with a dense green flame, and the production of much muriatic
acid, it was soluble in alcohol, but insoluble in water, at the bottom
of which it lay in drops.

Finally, MM. Macaire and Marcet’ proceeded to analyze these
fluids, and this they effected by oxide of copper: one hundred
parts of the pyroxilic spirit or pyroligneous ether gave

44.53 of carbon, or 6 atoms.
46.61. oxygen, 4 ,,
9.16 hydrogen, 7 ,,

One hundred parts of the pyroacetic spirit of Chenevix gave

55.30 of carbon, or 4 atoms,
36.50 oxygen, 2 ,,
8.20 hydrogen 3 ,,

Analyzing alcohol of specific gravity .820 at the same time, one
hundredparts gave
48.8 of carbon, or 3 atoms.
39.9 ., oxygen, 2 ,,
11.3, hydrogen 5 ,,

’ The conclusions of the mémoire are, lst. That there exist at
least two simple vegetable fluids distinct from alcohol, but like
that liquid, having the property of forming with acids, particular
ethereal spirits ; 2nd. That these two fluids which may be distin-
guished by the names pyroacetic spirit and pyroxilic spirit, differ
from each other, both in their properties and composition. — Bib.
Univ. xxiv. 126.

We suspect some mistake in the printing of the figures of the
analysis, for there is no accordance in the estimation of the weight
of the atoms deduced from them. If the weights expressed be di-
vided by the number of atoms assigned, and the whole be reduced
to the atom of hydrogen, as unity it gives the weight of an atom
of carbon 5.67 by the first analysis, 5.06 by the second, and 7.2
by the third, and the weight of an atom of oxygen as 8.9 by the
first analysis, 6.67 by the second, and 8,82 by the third. — Ed.

29. Cafeine.—Cafeine is a crystallizable principle discovered in
1821, in coffee, by M. Robiquet, whilst searching in it for quina.
MM. Pelletier and Caventour obtained this substance at the
same time, but did not complete their researches. M. Robiquet
read a mémoire on this subject to the Société de Pharmacie of
Paris, which has not been published. It is, however, known to be
a new principle, white, crystalline, volatile, and slightly solubl—e.
Dict, de Med.

174 | Miscellaneous Intelligence.

Its composition is very remarkable, for according to MM.
Dumas and Pelletier, it consists of

Carbon . ‘ - 46.51
Nitrogen : . 21.54
Hydrogen. meray: %
Oxygen . : - 27,14

rT

100.

The quantity of nitrogen in it surpasses that of most vegetable
substances,—Ann. de Chim. xxiy. 183.

30. Conversion of Gallic Acid into Ulmin—The following state-
ment is by M. Doebereiner. On dissolving a determinate quan-
tity of gallic acid in ammonia, and placing the solution in contact
with oxygen, it absorbed sufficient to convert all the hydrogen of
the gallic acid into water. In this way the acid became conyerted
into ulmin, which is composed of

1 atom .).: . 12 carbon
#6 OSURE hydrogen
2 - 6. oxygen

and may be represented as a combination of two volumes of gas-
eous oxide of carbon, and one volume of vapour of water.—Ann,
de Chim. xxiv. 353.

There is some mistake in the above statement of the composi-
tion, but the fact is very curious— Ed.

31. An Account of an Electrical Arrangement produced with dif-
ferent Charcoals, and one conducting Fluid, communicated by Mr. T.
Griffiths.—In the course of some experiments on charcoal, the re=
sults of which are given in a late number of the Journal of Science,
two specimens were obtained differing remarkably in mechanical
texture, and electrical conducting power, but more especially in
the former. One of them being soft and porous, absorbing water
with great avidity; the other hard and compact, absorbing it with
comparative slowness. I was induced from the observation of this
fact, to try if it would be possible to form an electrical arrange-
ment of several such pieces made into ares and plunged into
glasses of water; supposing that the absorption of that fluid tak-
ing place more rapidly in the one than the other, might at the’
time develope electricity.

An apparatus was accordingly constructed, consisting of several
pieces of the two charcoals united by a wire into the form ofan
arc, and dipping at their extremities into glasses of pure water.
Upon connecting its opposite ends with the tongue, «a perceptible
taste was experienced similar to that produced by a very feeble

Chemical Science. | 175

galvanic combination; the limbs of a newly-killed frog underwent’
evident convulsions when made part of the circuit.

In order to remove any source of fallacy that might have at-
tended the employment of a metallic wire to connect the charcoals,
another apparatus was made.in which they were united into arcs
by cotton or silk threads, and upon examining it by the tongue
and the limbs of a frog, the effects were similar to those before
preduced in the first form of experiment.

Upon making a tube filled with water part of the circuit, a de-
composition was expected, but none took place, although the ex-
periment continued several hours, nor would it revive copper from
its solution in sulphuric, or acetic acids, so that its respective
poles have not been distinguished.

In all experiments made with this apparatus, the employment of
metals was carefully excluded, so that their contact with the
charcoal should not give incorrect results.

If when the limbs of a frog are undergoing convulsions, one of
the arcs be removed from the circuit, they instantly cease, but re-
turn again, upon its being replaced; and it is a curious fact that
the effect on the limbs is decidedly most powerful, when the nerve
is in contact with the rapidly absorbing surface; if the opposite
arrangement be adopted making the muscle in contact with it, the
effect is greatly diminished, or altogether ceases.

That the activity of the apparatus is dependent upon the ab-
sorption of water, is proved by its cessation in about twenty-four
hours, the charcoals becoming saturated with water ; but by heating
them red hot it is expelled, and upon again arranging them in the.
manner mentioned, they will be found to regain their former ac-
tivity.

A solution of common salt, being employed as the fluid, aug-
ments the effect of the apparatus, it being a better conductor; but
if it is wished to heat the charcoals for another experiment, they
should be soaked in water to dissolve the salt, which would other-
wise fuse, and fill up the pores. ‘The woods from which the char-
coals are obtained, are known by the names of Botany Bay, and
King wood. The former should be chosen full of dark streaks,
which open when exposed to heat, and give the resulting char-
coal a great degree of porosity. In selecting the other wood, no
very particular attention is required, it generally producing a
charcoal of pretty uniform density.

II. Naruran History.

1. Vegetation at different Heights.—The following is a table
constructed by Mr. Bakewell, of the height at which various trees
and shrubs grow in the Vallois and Savoy. The extreme height

176 Miscellaneous Intelligence.

implies situations open to the south and west, and sheltered from
the north-east wind, the height varying very much according to the
aspect in an alpine country. The heights are expressed in English
feet above the level of the sea, lat. 45° 30’ to 46° 30’.

Vines . : : 4 2380

Maize ‘ ‘ 4 PME
Oak A 4 : 2 3518
Walnut tree ; . : 3620
Yew tree . : . ; 3740
Barley, : : . 4180
Cherry tree. ! 4270
Potatoes . " 4 4 4450

Nut tree . £ - - 4500
Beech tree i 4 Z 4800
Mountain Maple " 4 5100
Silver Birch ns , ‘ 5500
Larch 4 F : x 6000
Fir le sapin . : ; 6300
Pinus cembra . 4 6600
Rhododendron . : 7400

The line of trees reaches the height of 6700, the line of shrubs
8500. Some plants on a granitic soil grew at 10,600, above which,
are a few lichens, but vegetation ceases at 11,000. In the Garden
of the Inn, kept in summer at the Schwarrenbach, on the passage
of the Gemmi, carrots, spinach, and onions, are cultivated at the
height of 6,900 feet.

In the southern part of Savoy, the height at which pines will
grow is about 2,600 feet, but near this elevation the crops failed i in
the cold summer of 1821.—Bakewell’s Travels.

2. Irritability of Plants —Whilst experimenting on the irrita=
bility of certain plants,as the sensitive plant for instance, Dr. Meyer
had occasion to observe, that of those substances which acted by.
being absorbed into the plant, the most volatile were also the,
most powerful, although not the most destructive. When the ex-
treme leaflets of a branch were moistened with naphtha or essential
oil, the influence gradually extended itself to the neighbouring
leaflets, and even to the other leaves of branches. ‘Their recovery
was in the inverse order of their depression. Another observation
by the same author on these plants is, that when affected by a
trembling motion the leaflets close, but if the motion be continued
or some hours they will again open.—Brb. Univ. xxv. 53.

3. Notice of an undescribed Larva which attacks and devours
Snails.—The account of this larva was read before the Society of
Natural History of Geneva, by Count Milzinsky. As far as the

Natural History. 177

Count could ascertain. by reference to books, and. by inquiry
amongst those best acquainted with insects, it had never been
described. ‘The insect was five or six inches long, and two or
three broad; its colour yellow; it was furnished with two long bi-
furcated mandibles ; had at the upper part two brown antenne,
each composed of two articulations, and supported on a white
membraneous projection; beneath the mandibles were four feelers,
two of them in constant motion. The body is divided into twelve
rings, the three anterior have each two strong feet, and but little
hair; the following eight have each two false. feet, and on each ~
Side two tufts of hair; the twelfth has two large terminal tufts of
hair, which serve as a case to a sort of cartilaginous tail which
the animal moves at pleasure and uses as a sort of supplementary
foot: it is hollowed at the extremity, and covered with a viscid
humour. Between the lines formed by the tufts are two ranges of
projecting glandular black points, considered by M. Milzinsky as
trachia.

The larva is excessively voracious, attacking and apparently
feeding entirely on snails. On meeting with a snail, if the animal
be out of its shell, the larva takes a position on the shell and does
not attack the snail until it has entirely entered its habitation; the
larva then approaches the right side of the snail and forcibly
plunges his head into it, helping itself powerfully by the use of the
hind foot. ‘The snail gives evidence of suffering, and endeavours
to withdraw into and go out of its shell, moving much about, but
in a short time it ceases its motion and dies. The means by which
the larva produced so quick a death to the snail could not be ascer-
tained, for all passed so much within the shell as to be withdrawn
from observation. During the time that the larva remains in the
body of the snail, either alive or dead, only the terminal tufts of
hair are seen without. The larva will sometimes in this manner
attack and destroy three snails in one day.

These insects are generally found in dry ditches or by hedges.
If a snail’s shell be observed that has recently fallen, and the first
spire be broken, one of these animals will almost certainly be found
within. They vary in size, and are proportionate to the snails in
which they are found. A small larva, on devouring a snail, grows
considerably, changes its skin, and then searches for a larger snail.
‘When it has attained its final size it attacks its last snail, rejecting
avith force, towards the middle of its operation, a semi-liquid de-
composing matter; and by the time it has eaten or emptied all the
contents of the shell (the shell remaining clean) it has become
large, white and shining; it then remains inactive for a variable
portion of time, afterwards changes its skin, but in a manner
different to the previous changes, and becomes achrysalis. In this
state it remains awhile, and preserves its tufts, but less apparent
than in the former state. The chrysalis remains at the bottom of
» Vor, XVII. N

178 Miscellaneous Intelligence.

the shell for two ‘or three months, and then on a sudden be-
comes white; shortly the spots and colours of the skin appear,
and the insect ultimately passes into its perfect state, when it de~
posits its eggs. All these changes take place within the shell, and
it is difficult to ascertain them without disturbing the animal and
deranging the results.

Drawings of the animal having been shewn to MM.La Freille and
Audouin, they are inclined to believe that the insect in its perfect
state is not merely a new genus, but a particular family, which
they would place in the order of Thysanours, or in that of para-
sites:— Bib. Univ. xxiv. 137.

4. Hatching Fish—The Chinese have a method of hatching the
spawn of fish, and thus protecting it from those accidents which
ordinarily destroy so large a portion of it, The fishermen collect |
with care on the margin and surface of waters all those gelatinous
masses which contain the spawn of fish; after they have found a
sufficient quantity they fill with it the shell of a fresh hen’s egg,
which they have previously emptied, stop up the hole, and put it
under a sitting fowl. At the expiration of a certain number of
days they break the shell in water warmed by the sun, the young
fry are presently hatched, and are kept in pure fresh water till they
are large enough to be thrown into the pond with the old fish. The
sale o spawn for this purpose forms an important branch of trade
in China.

5. Natural Changes in Carrara Marble.—Carrara marble pre-
sents, according to M. Ripetti, an instance of chemical changes
in the colouring principles without any alteration in the carbonate
of lime. The marble of Carrara does not always possess that
brilliant whiteness for which it is so famed; it is for the most part
of a greyish tint, and is of its utmost whiteness only in certain .
parts where veins have been formed, or else spots of oxide, sul-
phate, or sulphuret of iron. Some of these stains are old and
fixed, but others seem to be of recent formation and are removed
by water running over them, so that ina short time the marble be-
comes as white as snow. ‘The workmen express this effect by say-
ing, ‘ The marble cleanses itself.” Whole masses seem to change
by a chemical process, and in support of this opinion, it has been
observed that the marble of the ancient excavation of St. Silvestro,
which was formerly of no value, has now become excessively white :
and that in general the different species of Carrara marble vary
with time, and become more and more pure.—Gior. de Fisica.

6. Note on the existence of a Nitrate and a Salt of Potash in
Cheltenham Water, by M. Faraday, Sc.—Having undertaken at the
request of Dr, Creaser an examination of some water from Chelten-

Natural History. | . 179

ham, had occasion to remark in it the existence of two substances
not fore observed in waters from that place; and though of no im-
partoneain a medicinal point of view, yet as relates to the sources
from whence the waters obtain their impregnations, and to the
istration they afford of the use of two tests suggested by Dr.
Wollaston but not very frequently, I believe, in the hands of che-
mists, they may I think possess interest; one .of these substances
is nitric acid, and the other potash. '
__ The source from which the water was obtained is called, I be-
lieve, the Orchard Well. It had been some time in disuse, but has
more lately been cleaned out and deepened, and is now about fifty-
six feet to the bottom. ‘The solid contents of a pint of this water
examined in London were,

Carbonate of lime . WER Bes
Sulphate of lime . . . . . 14°5
Sulphate ef magnesia. . . . 12°4
Sulphate of soda Tet ae 3°7
' Mutiateofsoda . . . . . 97:0
129:2

‘Besides which, the water contained a portion of carbonic acid; and
a small quantity of peroxide of iron had settled to the bottom of
the bottle.

On adding sulphuric acid to a portion of this water in quantity abun =
dantly sufficient to decompose all the salts subject to its action, and
boiling such acidulated water in a Florence flask, with a leaf of gold
for half an hour or an hour, the gold either in part or entirely dis-
appeared, and a solution was obtained which when tested by pro-

_to-muriate of tin, gave a deep purple tint. Hence the presence of
nitric acid, originally, in the water was inferred, and that no mis-
take might occur, a solution was made in pure water of all the

salts except the nitrate found in the water, boiled with some of the
same sulphuric acid, and tested by the same muriate of tin; but
in this case no colour was afforded, or any gold dissolved.

The potash was ascertained to be present by evaporating a quan-
rhe the water until reduced to a small portion, filtering it and
then adding muriate of platina in solution, Three pints of water,
evaporated until about one ounce of fluid remained, gave an abun-
ae precipitate of the triple salt of potash and platina. In cases
where small quantities of the water was tried, it was necessary to
let the liquid stand an hour or two after applying the muriate of
platina, but the triple salt always ultimately appeared.

__ Two pints ef the water, evaporated to dryness in a silver cruci-
ble, gave on re-solution of the residuum a decided though very
minute trace of silica.

4 « N 9

180 Miscellaneous Intelligence.

7. Llodine in Mineral Waters, &c.—At p. 168 of the last volume
of the Journal, was noticed the presence of iodine in the waters of
Sales in Piedmont. It was discovered in them by M. Angelina.
It appears that since then M. Kriiger of Rostock, has found iodine
in the mother liquor of the saline springs of Siilzer in Mecklen-
burgh-Schwerin, and M. Fuschs has found the same substance in
the mother water of the Sal Gem of Hall in the Tyrol. It ap-
pears, however, that as yet the iodine has not really been sepa-
rated from their mother liquors, but its presence has been ascer-
tained by the blue colour given to starch dissolved in nitric acid,
and. there appears to be no doubts in the minds of the experiment-
_ ers on the reality ofits presence.—Gvor. de Fisica. '

8. New Vesuvian Minerals—MM. Monticelli and Covelli
mention the following minerals as having been sent forth to the sur-
face of the earth during the eruption of Vesuvius in October,
1822. 1, Two small pieces of true lapis lazula found in the
red sand sent forth on the 24th of October. 2. Several
varieties of quartz, resinous quartz, and its passages into a lava
composed of amphigene and pyroxene. 3. White and green
phosphate of lime in fine hexaédral prisms and acicular crystals.
4, Perfect cubes of melilite, much larger than. those of Capo di
Bove. The two latter species were found in a current on the
sides of Monte Somma above Pollena. 5. Gehlenite resembling
that of Tassa. 6. Specula iron in brilliant plates above an inch
wide. 7. Oxide of iron in octoédrons, above half an inch in dia-
meter; the same also in mammelated or fused masses. 8. Anti-
monial iron. 9. Glass of antimony apparently containing a small
quantity of osmium.—Bvb. Univ. xxy. 42.

9, Products of Combustion of certain Coal Strata.—In the neigh-
bourhood of Aubin (Aveyron,) there exist certain coal strata, some
of which are worked, and others are burning, having been on fire
for thirty or forty years. It has been remarked as singular that no
muriatic acid or ammonia occur in the products of this combustion :
much sulphurous acid escapes, and various portions of sublimed
sulphur, and acid aluminous efflorescences have been collected ;
but on chemically examining these and the other products ob-
tained, neither muriatic acid nor ammonia have been observed.
The coal nevertheless contains abundance of azote, and on distilla-
tion affords carbonate of ammonia.

10. Advancement of the Ground.—The inhabitants of the vil-
lage of Hayotte, in the parish of Champlain, Canada, were alarmed
on the 28th of August, 1823, by the motion of a large tract of
Jand, containing a superficies of 207. arpents, It moved five or
six arpents, (about three hundred and sixty yards) from the water’s

Natural History. 181

edge, and precipitated into the river Champlain, overwhelming in
its ~progress barns, houses, trees, Gc. The river was dammed up
for a distance of twenty-six arpents in an instant with an awful
sound, and a dense vapour, as of pitch and sulphur. Various
causes have been assigned for this phenomenon, of which the most
probable, is the insinuation of water between the strata.—Phal.
Mag. \xii. 470.

Al. Existence of Free Muriatic Acid in the Stomach.—'The fol-
lowing are the proofs of the existence of free muriatic acid which
Dr. Prout has laid before the Royal Society. The contents of a
stomach having been digested in distilled water, the solution ob-
tained was divided into four equal parts. One of these evaporated
to dryness, burnt and examined in the usual way, gave the quantity
of muriatic acid in combination with fixed bases. A second being
previously saturated with an alkali, was treated in a similar way,
and gave the whole quantity of muriatic acid in the stomach, A
third carefully neutralized with a known solution of alkali, gave the
quantity of free acid. The fourth was reserved for any required
experiment. In this way Dr. Prout ascertained that the unsatu-
rated muriatic acid in the stomach was always considerable, and in
one case twenty ounces of a fluid from a very deranged stomach,
afforded him above half a drachm of muriatic acid of specific gra-

vity 1.160.

(12. Use of Sulphate of Copper in Croup. —Dr. H. Hoffman re-
commends the sulphate of copper as an excellent remedy in croup,
especially after blood-letting. In slight cases he begins with
giving from a quarter to half a grain every two hours ; in those
cases, however, where there is also laryngites, or bronchites, three,
four, or more grains are administered, so as to excite instant
vomiting ; by so doing, the Dr. thinks that not only is the lymph
expelled from the trachea, but also that the further secretion of it
is prevented, so that the patient is very much relieved, and soon
‘cured. After copious vomiting has been produced, the medicine is
to be given in small doses, in conjunction with digitalis. In sup-
‘port of the utility of the above practice, Dr, H. affirms that he has
employed it with the greatest success during a period of ten years,
‘in a great number of children affected with croup, without ever
having lost a patient in that time, notwithstanding the disease was
often at its height when he was first called in. —Med. Rep. N.S. 1. 85.

13. On Sand-drigs or Fulgorites, by MM. Viedler and Hagen,.—
The ensuing observations have been selected from the account given
‘in the Bib. Universelle, respecting these naturat sand-tubes, by
MM. Fiedler and Hagen, ‘The latter person was particularly well
circumstanced in ascertaining the cause of their formation, The

182 Miscellaneous Intelligence.

Report of Dr. Fiedler states, that being anxious to investigate the
circumstances and formation of these tubes in the sandy istricts
of Austria, he passed over those parts from Vienna towards Hun-
gary, and from thence to Stampfen, in search of them, and was ul-
timately fortunate enough to find one on the most elevated part of
one of the hills, in the neighbourhood of Zankendorf, about a league
north of Malaczka, n

This tube was half an inch (of Leipzic) at the longest diameter
at the upper part. On carefully removing the sand round it, com-
mencing at some distance, it was found that at the depth of two
ells a thin bed of quartz, in large grains, occurred, and immediately
beneath that, a yellow plastic clay. The sand was now removed
round the tube, and it was found that although above it formed
an angle of about 80° with the horizon, yet it soon became
vertical, and continued so to its lower extremity. It was probably
at first some feet longer, but had been destroyed by the wind, for
fragments were found lying about, which, however, could not be
adapted to the upper end of the tube. At six inches from its upper
extremity a small branch, about 4} inches, passed off from it, and 32
inches lower the trunk was divided into two branches, The N. E.
braach was 7! inches long and terminated on the clay by a length-
ened swelling, hollow within, its surface being composed of fused
siliceous sand. In many places the course of the electric fluid
could be perceived on the clay by the various red tints it had pro-
duced, which penetrated the clay to a depth of eight inches. The
fusion appeared to haye ceased when the electricity gained the
clay. The S.E. branch was 14 inches longer than the other; be-
fore arriving at the clay it passed close round one side of a piece
of quartz, an inch in diameter, and was fused to it. It terminated
on the clay just as the other branch did, the extremities being
removed about 2£ inches from each other.

In many places the tube was contracted to a small diameter, in
which places long bulbs had been formed, but the tube itself was
hollow within to a considerable extent. It resembled exactly the
tubes of the same kind found in the lands of Senner, and like them
was surrounded with red sand*. Just beneath the point of separa-
tion lay a quartz pebble, but as it was entirely surrounded with
sand, it probably had no influence in producing the division.

The following is from the account given by M. Hagen, of a tube
formed by lightning, and which he examined soon after its forma—
tion, Itoccurred at the village of Rauschen, on the shores of the
Baltic, in the province of Sarnlande. A storm occurred on July
17, 1823, which, about evening, approached the village; near
seven o'clock the clouds descended towards a young birchetree,
about twelve feet high, and the lightning descended along its trunk

* The sand in the neighbourhood became red by heat.

Natural History. 183

and penetrated the soil at its foot. A man, who was standing at
the door of a building, about fifty steps off, saw a juniper bush
still burning under the tree, but it was soon extinguished by the
rain. The neighbours immediately came together at the tree;
they found two narrow deep holes in the earth, and affirmed that
one of them was hot to the touch.

On examining the tree and place two or three days afterwards,
slight traces of the passage of the lightning was found on the tree,
and the juniper bushes and herbs in the neighbourhood of the tree,
were generally charred. The holes in the earth, however, pre-
sented no signs of combustion, not even on the small roots which
appeared on their inner surface. The soil was a coarse yellow
sand, reposing, at the depth of two feet, on a bed of vegetable earth.
On removing the sand, §., it was observed that oneof the holes
did not descend more than a foot, and offered nothing remarkable,
but a little lower down, the commencement of a vitreous tube was
found; the tube could not be removed whole, because of its fragi-
lity, but the fragments were collected, and it was found to have
penetrated even into the vegetable earth, where, though many
grains of sand had been agglutinated, they had not formed a regu-
Jar tube. The fragments were covered with a black matter. The
other aperture, which had been fonnd hot after the descent of the
lightning, did not seem to be acecmpanied by, or terminate in any
vitreous tube.

Some of the fragments withdrawn were three inches long, and all
were distinguished from similar tubes or fragments from other
places, by their thinness and fragility; they were scarcely as thick
as paper, and were semi-transparent. The surrounding sand ap-
peared blackened here and there; the interior of the tube was

right and shining from a thin coat of flux. It was of a pearl gray
colour and beset with black points. The tubes were flattened, and
extended on opposite sides in a zigzag direction. The sides of the
tubes, in some parts, almost came together, but no branches were
sent off, except where it had penetrated the vegetable earth, and
at that part it became almost filamentous. The fragments together
formed a length of above 214 inches. On examination, the black
powder appeared to be carbonaceous, for it resisted the action of
acids, but disappeared before the blow-pipe,—Bzb. Univ, xxiv, 106;

'

184 Mr. Moseley on the Star Algol.

On the Recurrence of the Smallest Light of the Variable Star Algol.
by W. M. Moseley, Esq. Sort

Blackman Street, March 22, 1824.
My dear Sir, -
If you can find a space for the accompanying communication,
you will render a service topractical astronomy.

I remain, dear Sir,
Yours, very truly,
J. Sourn.
To W. T. Brande, Esq.

Winterdyse House, Bewdley,
March, 20, 1824. |
** Dear Sir,

“In compliance with your suggestion, I transmit you a table
of the recurrence of the smallest light of Algol; the most remarkable
of all the variable stars; Professor Wurm has inserted in Bode’s
Jahrbuch. for 1822, p. 119, a table of this periodical change
during the years 1820, 1821, and 1822, and what I now send,
is a continuation for the ensuing summer, calculated from the |
data given in the professor’s introductory dissertation. He
informs us, that he had verified the period of the change of light,
by comparing a recent observation of his own, on September, 23rd, |
1813, with Mr. Goodrich’s, of earliest date, or January 31st,
1783, after 4540 revolutions had occurred in the interval. The
complete change occupies eight hours, or eight hours forty mi-
nutes ; but this period is very difficult to ascertain accurately.

The star when smailest, appears of the fourth magnitude; but
when brightest, of the second. It seems, however, from Mr.
Goodrich’s observations, that when at a maximum, its brightness

Mr. Moseley on the Star Algol. 185

is different at different times; and Mr. Pigot remarks, that it
sometimes is more /wminous than Persei. It is convenient to
place abar in the eye-piece of the telescope, of such diameter as
just to cover a star of the fourth magnitude; the enlargement will
then be more distinctly perceived in its progress ; but it will re-
quire considerable experience to mark the extremes satisfactorily.
The table is reduced to mean time at Greenwich. The recurrence
of the most diminished light is given to the nearest minute ; and
on those days only when the star may be distinctly seen at the
expected hour.

1824.

H. M.

April 14 . 10.25
17 es . 7.14

May 7 en ioc
24 13.51

June 13 15.34
16 : 12.23

19 “ 9.12

July 6 14. 6
9 10.54

26 15.48

EA ate : SBM ei
August 1. : «e926
Vie : - 14.20

20 11. 9
23 . 7.58
" Sept) °7 16. 3
10 ; 12. 52
GATOS sae A ae
16 6.30

“| beg you will dispose of this account as you think proper, and
Vou. XVII. O y

186 Mr. Moseley on the Star Algol.

I hope it will be found to correspond with the phenomenon. It is
a tedious process to go through, but I hope I have made no
mistake. ~ I remain, dear Sir,
Yours, very respectfully,
W. M. Moszxey.
“To J. South, Esq.

Nore.
“To preclude all possibility of error in identifying the star, its
right ascension is 2" 57’ and declination 40° 16’ N.”

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THE

QUARTERLY JOURNAL,

July, 1824.

Art. I. On the Horary Oscillations of the Barometer, By
J. Frederic Daniell, F.R.S.

Havine haa occasion, some time ago, to inquire into the facts
regarding the daily periodical fluctuations of the barometer, I was
greatly struck, not only with the regularity of their occurrence, but
with their gradual decrease in proceeding from the equator towards
the poles, as shewn by the experiments of different observers. The
following table constructed from the best authorities, places this
circumstance in a striking point of view.

‘ TABLE I.
Mean Periodical Movement of the Barometer, at different Latitudes.

North Dintiende) Mean periodical move-

‘i ier
Namésiof ‘Places, ment of the Barometer

St.Thomas’. ...| 0.24 | 0.074 inch
Sierra Leone 8.29 0.073
Trinidad... ... . | 10.39 0.063
Jamaica ......| 17.56 | 0,058
Clermont-Ferrand . | 45°47 0.039
oS Por 48,50 0.028
i §1,.31 0.015

Vou, XVII. P

190 Mr. J. F. Daniell on the

In endeavouring at the same time to account for these pheno-
mena upon the known laws of aériform fluids, I was led to con-
struct an hypothesis which appeared to me to explain this gradual
decrease of the oscillations ; but at the same time pointed out a
condition of the problem which would at once, if confirmed by ex-
perience, be a test of the correctness of the solution.

Let us suppose that in the atmosphere surrounding the earth a
circulation is kept up between the poles and the equator; and that
the cold dense air of the former regions flows in a lower current to
the latter, while the elastic air of the latter is returned in an upper
current to the former. There can be no difficulty in imagining
further that, as long as these currents are maintained with regular
velocities, a barometer, at all intermediate stations, might exhibit
an equal pressure of the a€rial columns; for as much air would
flow from their summits as would be returned to their bases. A
general alteration of temperature, which equally pervaded both
currents, would produce no alteration in the weight of a vertical
section, comprising both; nor would a partial alteration equally
diffused through the upper and under section of any one column.
The velocities of the currents would be partially altered thereby,
but the higher and lower would still compensate each other. But
an alteration of temperature which affected the upper and lower
currents unequally, would produce partial expansions and con-
tractions, which would effect an unequal distribution of the pon-
derable matter. If the lower stratum of any perpendicular section
were expanded by heat, while the upper were unaffected, the out-
going current of that section would be increased, while the in-
coming current would be checked; and the balance of the two
being disturbed, the total weight would be diminished. On the
other hand, a local decrease of temperature would produce the
analogous contrary effect. Now the alternations of heat and cold,
produced by the changes of day and night, although they may be
regarded in a general way as pervading both currents, act with suf-
ficient inequality to induce us to expect a corresponding fluctuation
in the weight of the atmosphere at any particular point. The heat-
ing Surface being below, the warm particles quickly ascend, and

EE a es

= ity

ey

Horary Oscillations of the Barometer. 191

are immediately replaced by the cold particles from above; and
by this circulation the diffusion of heat is very rapid. But the
exchange of particles between the upper and lower strata must
occupy some time, however small the interval, and the consequence
taust be that the barometer will measure by its fall the amount of
the inequality. So on the other hand, in the process of cooling, in
the absence of the sun, experiment has shewn that the lower strata
of the air become more rapidly affected by radiation than the
upper, and the total increase of weight from this cause, will be
shewn by the rise of the mercurial column.

If we trace this effect along any given meridian, we shall become
sensible of the manner in which this influence operates. Beginning
at the equator, the only circumstance which we have to appreciate
is the irregularity of the lateral expansion or contraction. As the
earth acquires warmth from the sun, the barometer falls; but the
check which the incoming current from the poles sustains, must be
felt along the whole line of its course; and its due velocity being
opposed, without any adequate compensation in the upper current,
the barometer would have a tendency to rise at all latitudes be-
tween the equator and the pole. Assuming an intermediate
station upon the same meridian, we should have the same effect
produced by the unequal expansion of the lower current of the
atmosphere, but opposed now by the impulse communicated from
the equator. The fall of the barometer would only then represent
the balance of the two effects, and must be less than at the equator.
The further we proceed towards the pole, the more must this re-
yulsive action accumulate, and the less must the balance of the
two become, till at some neutral point they are exactly equal.
Beyond this point, again, the former action would exceed the latter,
and the barometer would rise in the higher latitudes, while it was
falling in the lower.

The results of the preceding table obviously coincide with such a
gradual progress towards a neutral point: but up to the time when
I published an essay upon this subject, there were no experiments
to prove the corresponding opposite effect beyond this limit. By
‘a careful examination, with this view, of the meteorological register

P2

192 Mr. J. F. Daniell on the

kept at Melville Island by the expedition under the command of
Captain Parry, I found that there was distinct evidence of the an-
ticipated result. The barometer in that high latitude periodically
rose at those hours whenit is known to fall in the southern degrees.
The following tables present the monthly means arranged in the
proper order for exhibiting the conclusion.

In the first, including the winter half of the year, it will be ob-
served that the mean temperature scarcely varied from noon to
midnight: the effect of the remote equatorial expansion was there-
fore unopposed, and the barometer constantly rose from 6 A.M. to
6 P.M., in coincidence with the fall in the lower latitudes. From
6 P.M. to 6 A.M. it as constantly fell.

In the second, comprising that portion of the year when the sun
was above the horizon, the daily variations of temperature were
considerable, and the effect less regular, but nevertheless the baro-
meter constantly rose from noon to 8 P.M., and then descended to
midnight,

TABLE II.

Shewing the mean heights of the Barometer and Thermometer at four
different hours of the Day at Melville Island.

1819 6 A.M. Noon, 6P.M. Midnight.

Bar. |Ther.|| Bar. |Ther.
29.920 |4-22.7]] 29.890 |4+21.3

29.840 |— 3.9]) 29.825 |— 5

Bar. |Ther.|} Bar.
29.884 |4-21.5]| 29.906 |4-23.7

29.777 |— 4 || 29.808 |— 2.8)
29.935 |—21 29.946 |—20.)
29.874 |—23 29.872 |-21
30.040 |—30.3)| 30.036 |—30
29.741 |—32.8)]| 29.758 |—30.8
10 days of March| 29.551 |—19.1]| 29.561 |—14.5

September ..
October....

ember .. 29.946 |—20.1)| 29.937 |—21.2

December .. 29.881 |—21.1)| 29.893 |—21.6
1820
January.... 30.068 |—29.9)| 30.063 |—30.4

February ... 29.782 |—32.6)| 29.771 |—33.5

29.614 |—18.5|| 29.571 |—20.5

———

ae ———

29, S644 29.8500
+.0234 —.0144

Means... | 29.8288 29,8410
— .0212 | +.0122

Difference .

193

Horary Oscillations of the Barometer.

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194 Mr. J. F. Daniell on the

Upon the return of the last expedition from the northern coast
of America, I was “extremely anxious again to bring my hypothesis
to the test of experience, and for this purpose was favoured upon
application, with the loan of Captain Lyon’s Meteorological Jour-
nal. This, as well as all other nautical registers which I have had
an opportunity of examining, has been kept with the utmost pre-
cision and neatness ; and it is highly gratifying to find so much
attention to the interests of science amongst our naval officers,
who have such opportunities of enlarging our acquaintance with the
different climates of the globe. The periods of the day were
almost as favourable as possible to the comparison, but the lati-
tudes were not as far removed as that of Melville Island from the
influence of variations of daily temperature. The following table
presents the monthly means of the observations for two years,
during which the Hecla was confined between the latitudes
66° and 70°:

TABLE IV.
Shewing the Mean Heights of the Barometer and Thermometer at four
different Hours of the Day on board H, M. 8. Hecla, between the
Latitudes 66 and 70.

A.M. 4 A.M.8 P.M. 4 P.M.8
1821 Bar. Ther, Bar. Bar. Ther. Bar.
August . .« || 29.835 33.5 || 29.846 || 29.848 39.9 |} 29.825
September . || 29.958 29.8 || 29.974 || 29.973 34.3 |} 29.977
October . . || 29.881 8.9 || 29.876 |} 29.889 17.6 |} 29.898
November. || 30.166 2.7 || 30.156 || 30.165 12.6 || 30.159
December . || 29.904 | —19.2 || 29.898 |} 29.914 | —11.5 || 29 918
1822
January . « || 29.921 | —26.9 || 29.924 |} 29.933 | —20 29.952
February . . || 29.762 | —27.5 |} 29.746 |] 29.753 | —18.5 |] 29.761
March . . . || 29.849 | —17 29,854 || 29.864 ] — 3.8 |} 29.852
April . «. . |} 29.895 | — 0.2 }| 20.993 || 29.907 | 413.9 || 29.918
May .. «|| 29.985 13.5 |} 29.957 || 29.973 | +31.5 |] 29.978
June . . «|| 29.886 26.9 || 29.877 || 29,897 38.2 || 29.868
July . . ¢|| 29.682 32.7 || 29.693 || 29.694 | 40.6 |] 29.702
August . . || 29.643 31.5 || 29.636 || 29.661 36.5 |] 29.667
September . |} 29.883 22.2 || 29.883 || 29.895 28.3 |} 29.894
October . . || 29.967 10.7 |) 29.981 || 29.981 13.1 |} 29.985
November, || 29.875 | —22.6 || 29.876 || 20.884 | —13.4 |] 29.882
December + || 29.756 | —32.5 |) 29.739 || 29741 | —25,4 || 29.726
1823
January . .« || 29.877 | —20.2 || 29.902 || 29.898 | —10.6 |} 29.893
February . , || 29.904 | —24.9 |) 29.906 |} 29.905 | —13.4 |} 29.907
March . « || 30.950 | —24.1 | 30.055. || 30.050 | —12 30. 06L
April . . «|| 29.957 | — 9 |) 29.955 || 29.957 | ++ 7.5 |] 29.954
May . . «|| 29.929 | +16.9 |} 29.916 || 29.920 33.3 |] 29.921
June . . . || 29.922 | — 23.4 |} 29.910. || 29.909 41.2 || 29.909
Juky S << || 29.507 33.2 | 29.499 || 29.509 43.8 |} 29.508

29.850 29.87%
-L.G0S —.001

Mean . . || 29.874 | 29.872
; Difference || — .005 | — 602

Naepeneetenpensener ninemsn

Heorary Oscillations of the Barometer. 195

It appears from this table that the rise in the mercurial column
from 8 A.M. to 4 P.M. was nearly constant, and upon further
examination it will be found that in the only two exceptions of any
amount, namely the months of January and March 1823, some
unusual influence prevailed in the atmosphere. The first was
distinguished by an unusually high mean temperature, and fre~
quent storms of wind. Captain Parry remarks in his Journal,
“from the morning of the 24th till midnight on the 26th, the
mercury in the barometer was never below 30.32 inches, and at
noon on the latter day had reached 30.52 inches, which was the
highest we had yet observed it in the course of this voyage.
This unusual indication of the barometer was followed by hard
gales on the 27th and 28th, first from the S.W., and afterwards
from the N.W., the mercury falling from 30.51 inches at 8 P.M.
on the 26th, to 30.25, about 5 P.M. onthe 27th, or about 0.26 of
an inch in nine hours before the breeze came on. At midnight on
the 27th it had reached 29.30, and on the following night 29.05,
which was its minimum indication during the gale. These high
winds were accompanied by a rise in the thermometer very unusual
at this season of the year, the temperature continuing above 0°
for several hours, and very near this point of the scale for the
whole two days.”

The month of March, on the contrary, was as much below the
mean in temperature, as January was above it, and the observation
renders it probable that the usual course of the season was modi-
fied by some extraneous cause. ;

Iam aware that it may be objected, that these observations
were not made with all the precision that the accurate determi-
nation of such small quantities requires, and particularly that the
heights of the barometer were not corrected for the variations of
temperature. The objection, to some extent, is certainly valid, and
it is much to be lamented that the advantages of the utmost at-
tainable degree of precision in these observations have not hitherto
been duly appreciated : but when it is recollected that the instru-
ment made use of was placed in the cabin of the ship, where con-
siderable pains were taken to maintain an equal temperature, it

196 Mr, J. F.. Daniell on the

will be found that less importance attaches to the omission in this
particular instance than might at first be supposed. In the last
voyage, more especially, the precautions which were adopted to
secure this important. end, were eminently successful. It appears,
for instance, by Captain Parry’s register, that in the months of
October and November, the mean temperature of the external air
varied 32°, while that of the air of the lower deck only
varied 5°, so that the changes in the course of the 24 hours
could have been scarcely appreciable. The return of the various
expeditions which are now about to depart once more for the
Arctic Regions, the officers of which have most zealously under-
taken to make the observations with all the requisite precautions,
will, it is to be hoped, set this interesting question at rest, and not
only determine the existence of the phenomenon which I have
ventured to anticipate, but also the exact amount of the fluc-
tuation.

I would here willingly have entered into some speculations upon
the mean height of the barometer as shewn by the registers of
the high latitudes, and which appear, upon the first view of the
subject, to be considerably below those of the more southern
regions, but doubts respecting the construction of the instruments
destroy the necessary confidence in the observations. These
doubts are more strongly than ever impressed upon my mind by
the inspection of eight barometers which were prepared for the
expedition which has just sailed from the river, by one of the first
opticians in London, and who undertook to bestow unusual pains
in their construction. No two of them agreed in height, and the
greatest difference was full 0.2 of an inch, One standard barome-
ter, however, now accompanies them, and may serve to determine
the errors of the others, so that little doubt exists that we shall
at length be able to arrive at some precise conclusions respecting
the fluctuations of the atmosphere in the most interesting and
inaccessible climate of the northern hemisphere.

The advantages to be derived. from a proper attention to the
construction of the barometer cannot be better exemplified than by
the circumstance of the same_ instrument-maker having since

Horary Oscillations of the Barometer. 197

completed five barometers of very different capacities and diame-
ters, whose difference from the mean and from the standard; with
all corrections made, was only .006 of an inch.

Arr. II. On the Alterations of Rate produced in Chrono-
meters by the influence of Magnetism. By George Har-
vey, Esq., F.R.S.E., &c.

Tne power which a magnetic force possesses, of accelerating
the rate of a time-keeper in some situations, and of retarding it in
others, is a fact which has been verified by many interesting and
important experiments. It is singular, however, that the same
attractive power, which when applied in different directions to one
‘chronometer, tends either to accelerate or retard its rate, should
in another, when allowed to operate under the same conditions, as
to intensity and position, produce results precisely the reverse. It
will be the object of the following paper, to refer these apparent
anomalies, to the varieties of imperfect isochronism, existing among
different chronometers.

To illustrate this view of the subject, suppose the balance of a
chronometer in its quiescent position, having its thermometer-
pieces in an active, but opposite state of polarity ; and let the line
joining those pieces, and which therefore passes through the centre
of the balance, denote the direction in which the magnetic force
acts. Now since the thermometer-pieces possess opposite polari~
ties, let that portion of the attractive influence which is destined
to operate on the time-keeper, and is of an opposite kind to the
polarity of the thermometer-piece on which it first acts, be allowed
to exert its energy, the moment the oscillations of the balance take
place. ‘The effect of such an application will be, a decrease in the
are of vibration, in consequence of the effort made by the thermo-
meter-piece, on which the magnetic force acts, to approach the
attracting pole. This alteration in the amplitude of the are of
vibration, will therefore occasion some variation of rate in the time-
keeper. If instead of supposing the attractive power to pass im-~

i

198 Mr. Harvey on the influence of

mediately through the thermometer-pieges, it be allowed to pro-
duce its effects, on either side the point of quiescence, within cer-
tain limits, the are of vibration will still be diminished, but in a
less ratio than before; and changes of rate proportional to the
variation of amplitude, will be the result.

Suppose in the next place, the direction of the magnetic force to
pass through the centre of the balance, and the limit of the semi-
are of vibration; it is manifest, when motion is communicated to
the balance, its effect will be to increase the arc of vibration, both
from its attracting one of the thermometer-pieces, and repelling
the other; and that therefore an alteration of rate, entirely the
reverse of the former, will be the necessary result. It is also evident,
that if the same attracting pole be applied on either side of its last-
mentioned position, within certain limits, the are of vibration will
still be increased, but in a less ratio than before; and alterations
of rate of the same kind, but of a less remarkable degree, will be
produced.

If the time-screws are supposed to be magnetic, and the ther-
mometer-pieces free from the attractive influence, similar results
will take place.

Conceive in the next place, that in addition to the magnetism of
the thermometer-pieces, the entire arcs of compensation possess
also a property of the same kind ; one half of each having northern
polarity, and the other half southern; then will the time-screw
attached to the are of compensation, whose thermometer-piece has
northern polarity, become a south pole; and that attached to the
arc, whose thermometer-piece has southern polarity, a north pole;
the transverse arm connecting the two, if of steel, presenting all
the properties of a perfect magnet.

In this point of view, the entire balance may be regarded as a
species of compound magnet, having two pair of opposite poles ;
and different phenomena will be exhibited, according to the direc-
tion in which the magnetic force acts. If, for example, the mag-
netic power be allowed to develop its influence, in a direction
equally remote from the opposite poles of each of the arcs of com-
pensation; and that we moreover suppose each pole to possess the

Magnetism on Chronometers. 199

same degree of intensity, the. acceleration or retardation produced
by the action of the exciting force on one of the poles, will be en-
tirely neutralized, by the opposite effects of the other. But if the
attracting power be allowed to operate in a position nearer to one
pole than the other, an alteration of rate will result from the change
in the are of vibration, necessarily produced by the inequality of
action. If on the other hand, the magnetic force be applied, in a
direction between the thermometer-piece and time-screw belonging
to the separate arcs of compensation, and having a polarity of a
contrary kind to them, a constant effort will be made by the
balance, to accommodate its arcs of vibration to the united effect
produced by the maintaining power, and the intensity of the mag
netic action; and a similar tendency will likewise be displayed by
the balance, if the disturbing pole be placed: in the vicinity of a
thermometer-piece and time-screw, having the same kind of po-
larity with it.

From the same considerations we may also infer, why a chrono-
meter, having a balance powerfully magnetic, should present vari-
ations of rate, from the influence of the earth alone, according as it
is situated with respect to the magnetic meridian. If the thermo-
meter-pieces alone are magnetic, and the line joining them be
placed in any other direction than that of the magnetic meridian, a
continual effort will be made by the balance to regain this position,
thereby producing a change in the arc of vibration. Ifalso, the entire
balance be considered as magnetic, some line may be found passing
through its centre, in which it would repose in the direction of the
magnetic meridian, if detached from the other chronometrical parts,
and freely suspended. Hence it follows, that the moment the time-
keeper is so placed, as to remove the balance from the Jast-men-
tioned position, a tendency will be created in it, to return to that
state; and which, by producing variations in the arc of vibration,
must at the same time be accompanied by sensible alterations of
rate.

Having made these general observations, I shall finally consider
the cause, why similar changes in the are of vibration, should be
frequently attended, in different chronometers, with opposite alter-
ations of rate,

200 Mr. Harvey on the influence of

It maybe questioned, if ever a chronometer existed, in which
the vibrations of the balance were perfectly isochronous; or
in other words, in which the adjustments of the spiral spring
were such as to admit of its elastic force, varying precisely
with the arcs of vibration. Mr. Atwood has shewn in the Philoso-
phical Transactions for 1794, that although the relation between
the elastic force of the spring, and the magnitudes of the arcs of
vibration, may appear to be in a perfect ratio of equality, there may
nevertheless exist such exceedingly minute deviations from this
state, as to render it impossible to be detected, by the most delicate
experimenter; and yet these minute inequalities may be consider-
able enough to produce in the interval of twenty-four hours, a sen-
sible alteration of rate. Hence it is, that the application of a mag-
netic force to a chronometer, having a balance in any degree mag-
netic, in almost every case, produces a visible alteration of rate.
In an example furnished by the able mathematician before quoted
he demonstrates, that a variation of a thousandth part from a per-
fect state of equality, in the relation between the elastic force of
the spring, and the arcs of vibration, is capable of producing an
acceleration of + 2”.62 in the daily rate, when the semi-are of
vibration is diminished 8°; and he even states, that an increase
of rate amounting to 20 or 30 seconds may exist, and yet the
differences arising from the deviation of the elastic force of
the spring, from the law of isochronism, be too minute to be ren-
dered sensible by any statical counterpoise of the force of the
spring.

Assuming therefore a perfect isochronism in the vibrations of a
balance, as a condition scarcely to be obtained, the deviations from
it, may be contemplated under two points of view; since the elastic
force of the spring may vary either in a ess ratio than the angular
distances from the point of quiescence, or in a greater; and which
suppositions will account for the apparent anomalies presented by
different chronometers, when subject to the action of a magnetic
force.

This will appear evident, by referring to the function, which ac-
cording to Mr. Atwood, represents the daily abberration of a time-

Magnetism on Chronometers. 201]

keeper, when the magnitude of the are of vibration is changed, and

which is
w{(5)F
a

where a denotes the primitive arc of vibration, a’ that produced
by the action of a disturbing force; and which, according to the
direction of its action, may be either greater or less than a; and x
the exponent dependent on the peculiar ratio existing between the
elastic force of the spring, and the angular distances from the
point of quiescence.

If we suppose the primitive are constant, and the other elements
a’ and x of the formula variable, the entire function, as Mr. Atwood
observes, will be susceptible of different modifications. Suppose,
for example, we attribute to x a less value than unity *, a condition
which corresponds to that of the elastic force of the spring, varying
in a less ratio than the angular distances from the point of quiescence ;
it is manifest, that different values will be communicated to the func-
tion, according to the value assumed for a. If the supposition alluded
to in an early part of the paper, of the attracting force passing through
the thermometer-pieces be referred to, and in which the are of
vibration would be shortened by its operation, the value of a’ must
necessarily become less than a; and a positive value being thus
communicated to the function, the time-keeper will gain.

In the next place, if the attracting force be conceived, as in the
second supposition, to pass through the centre of the balance and
the limit of the semi-are of vibration, and which application will
necessarily occasion a’ to become greater than a, the numerical
value of the formula will be negative, and the chronometer will lose.

If again we suppose n to be greater than unity, or the elastic
force of the spring to vary in a greater ratio than that of the
distances from the point of quiescence, the first of the preceding
suppositions with respect to a’, will give to the function a negative
value, indicating a retardation of rate in the time-keeper.

* If wesuppose z = 1, the whole function will vanish, in indicating a per-
fect isochronism ; so that whether the arcs of vibration be increased or dimi-
nished by the action of a disturbing force, no alteration of rate will take place.

202 Mr. Harvey on Chronometers.

In like manner, by referring to the case in which a’ is greater than
a, the numerical value of the function will assume a positive charac-
ter, and the chronometer will gain.

Thus, with changes in the amplitude of the arc of vibration, from
less to greater, or from greater to less, resulting from the applica-
tion of a disturbing force in different directions, will results entirely
opposite in their character be produced in different chronometers,
in consequence of Varieties of Imperfect Isochronism.

Plymouth, May 20, 1824.

Art. Ill. On Indistinctness of Vision caused by the presence
of False Light in Optical. Instruments, and on tts Reme-
dies. By C. R. Goring, M. D.

[Continued from p. 28]

Microscorts.—These instruments though but toys compared
with telescopes, nevertheless deserve to be rendered as perfect as
possible, for they yield not to them in the quantity and variety of
rational amusement which they are capable of introducing us to
(though not of the sublime description of the wonders of the
heavens). Compound microscopes though not so much to be
depended upon for the purposes of discovery and philosophical
investigation as single lenses, are still best adapted for recreation,
but all those which I have ever seen constructed on the common
principle, are so full of fog as to be quite disagreeable for exami--
ing opaque objects, which render this defect more striking than
transparent ones. This false light results from the custom of
making the object-glass of a very small aperture, instead of giving
it a larger one, and placing a stop in its proper place (the focus
of the lens employed). It is totally impossible to get rid of the
fog in any other way. No doubt the larger the aperture of the
lens of the common object-glass, the more indistinctness is sen-
sible ; and the more it is reduced, the less;—but no practicable con-
traction of the aperture will effect the desired purpose completely,

Dr. Goring on Microscopes. 203

because the principle itself is intrinsically bad, and incorrect at
least for low powers.

Now, if we form a microscopic object-glass of a single lens of
considerable aperture, haying a stop in its focus of about the same
diameter as the apertures of the common lenses used for com-
pound microscopes, (that is to say, about one-tenth or one-twelfth
part of their focal distance,) we shall form an object-glass which
gives a clear image, free from fog indeed, but very deficient in
other respects; for the stop being placed where the rays cross cach
other, a large portion of the aperture of the lens is called into
action, in comparison to what is usually made use of, when it is
at once limited by a stop of the same diameter applied close to the
glass; the aberrations both chromatic and spherical are here im=
mediately felt—to remedy these, another lens must be employed, the
best position for which is close to or very near the farther side of
the stop. The focus of it must be to that of the first as 3 to 2, oras
2 to 1—for low powers, however, it may be about 21 to 2—for the
higher the best proportions seem to me to be as2 to1l*, The
lenses employed should be plane convex, having their curves towards
each other as represented in Figs. III, IV, V, and VI, Plate II.
which are drawings of four object-glasses of this description which
I have caused to be executed the lowest power is 2 inches focus,
the highest 4 an inch—the foci of the lenses, and the size of the
stops, Sc., are as there represented +. These object-glasses I can

* The addition of this second lens has another good effect, for it enables
us to regulate the compound focus so as to haye the object as near to the
Object-glass as will consist with the distance which must be allowed for suf-
fering the rays from a lens or mirror to fall upon it for the purpose of illumi-
nation when opaque,—for the light of opaque bodies diminishes according to
the square of their distance, and thus the farther the object-glass recedes from
them, the less light it receives. With transparent subjects, however, the case
is different, at least when they are illuminated by the converging rays of a lens
orvoncave mirror ; for, by making the focus of this fall not upon the object but
upon the object-glass, the maximum of light is obtained at whatever distance the
object may be from the glass, so that the benefit of having them near each
other is not so much felt as in the former case—the proportions I have recom-
mended will answer every purpose.

t It will be obvious that a microscope of my construction may be used as

204 Dr. Goring on Microscopes.

confidently recommend as greatly superior to those in common
use; they are bright, clear, and distinct, free from spherical aberra-
tion, and will shew no sensible colour with opaque objects of any
kind, not even with so trying a one as the enamelled white
letters on a black ground generally used by opticians to try their
telescopes with. When, however, they are made to view an object
illuminated from behind, which does not suffer the light to pass
through it while its edges are seen, as for example the legs of some
insects, some kinds of moss, &c., which have very little trans-
parency, the uncorrected colour is then decidedly seen—such
objects are the best tests of achromaticity for telescopes as wel)
as microscopes ; equivalent terrestrial ones for a telescope will be
the bars of a window seen from the interior of the apartment to
which it belongs, or the naked branches of a tree in winter, seen
against the light of the sky, more especially of the sun, and
nearly opposite the observer. In addition to the four object-

a magnifier for a telescope, In factit is in its principle nothing but the four
glass erecting achromatic eye-piece of a day telescope a little modified (there
is alas nothing new under the sun). Indeed, many of Mr. Tulley’s astrono-
mical telescopes are so constructed that the night eye-pieces can be applied
to magnify the erected image formed by the two glasses, which do the work of
my object-glass. It would, however, be much better, instead of increasing
the depth of the eye-glasses in this case, to augment that of the erecting part,
as a much sharper image is in this way obtained. There certainly are many
objects which are seen better with this kind of eye-glass, such as Venus, and
many double stars ;—the number of refractions arrest a portion of the false
light or halo which so commonly surrounds these objects. However, the
same or nearly the same effects seem to be produced, by diminishing the
aperture of the object-glass of the telescope, except that this seems to increase
the spurious disc of the fixed stars, which the other method does not. Many
suppose that great advantages are to be gained by making a microscope
with a long tube, and a shallow eye-glass. I have satisfied myself repeatedly
by experiment, that whether the required magnifying power is obtained in
this way, or by a short tube with a deep eye-glass, the effect is precisely the
same. The body of my microscope is seven inches long, having an achro-
matic eye-piece of about one inch negative focus, just like those applied to
telescopes. I do not like the double and triple eye-glasses very commonly
applied to microscopes, as they are apt to give double images, with luminous
transparent objects,

Dr, Goring on Microscopes. 205

glasses I have described, I have two more of 1 and + of an inch
focus, which Ihave not inserted, because (though executed with
the utmost care,) they are no better than the common ones. I was
grievously disappointed with these, for I had fully expected that
the same principle applied to deep object-glasses would form as
superior an object-glass for high powers as for low ones: however
the reverse is the fact;—it is one of those things which can only
be learnt from experience, and could not have been predicated @
priori. There is doubtless a reason for this, but I am not able to
shew what itis. Still, therefore, the common object-glass is the
best for high powers, viz., for those of a quarter of an inch focus,
and upwards. My object-glasses are however deep enough for
all ordinary objects—certainly for all opaque ones. There are,
nevertheless, many transparent objects which cannot be seen with-
out object-glasses of at least 1, inch focus,—such are many
kinds of animalcules and the minute lines on the dust of a butter-
fly’s wing, §c. For these the common single lens of small aper-
ture will perhaps ever remain the only efficient object-glass,—an
equivalent power obtained with my object-glasses, or those of the
common construction of similar focus, by increasing the depth of
the eye-glass will never shew the objects in question, because what
may be called the penetrating power of a compound microscope
depends upon the depth of its object-glass, as that of a telescope
upon the aperture of the metal or glass which forms the image
viewed by the eye-glass. The eye-glass either of a microscope or
telescope merely developes what is contained in the image it
enables us to view; it cannot of course render any thing sensible
to our sight which does not exist in the spectrum formed by the
object-glass or metal. I may here mention that I had previously
constructed my microscope with one object-glass only of one inch
focus, and got my powers by increasing the depth of the eye-glass
as is done in telescopes. I however, found, that a large image
viewed by a shallow eye-glass made a much better instrument
than a comparatively small one (formed by a shallow object-glass),
viewed by a deep eye-glass; indeed the same position holds good
with regard to telescopes also, for the largest and longest (ceteris
Vou. XVII. Q

206 Dr. Goring on Microscopes.

paribus) are sure to be the best, because the image of such needs
but to be little magnified to procure a given power, and it must be
evident that the more an image is magnified the more its imper-
fections will become sensible, for no image can be free from im-
perfection like the object from whence it is derived.

I shall‘ here advert to a circumstance (though rather foreign to
my subject,) relative to the proper apertures of the common mi-
croscopic object-glasses, which is, perhaps, not duly attended to.
It is certain that the more their apertures are reduced (within a
certain point,) the more fog you exclude; and in this way you
improve the instrument,—yet if this reduction is pushed too far,
it will prevent you from seeing a certain class of objects, even
while the vision of others seems to be ameliorated. Thus the
parallel lines on the dust or feathers of a butterfly’s wing can be
just seen with an object-glass of #1, inch focus, and j4 inch aper-
ture as nearly as it can be measured: if, however, this aperture is
very slightly contracted, they can no longer be seen with any art
or management of the light,—at the same time other objects will
appear fogey and indistinct with this same aperture, especially
if opaque, and the vision of them will be improved by diminishing
it. I am disposed, therefore, to think that the apertures should
be regulated by this ratio of A, inch aperture to =, inch focus *.

* The great Sir W. Herschel! has condescended to notice this subject,
without however determining precisely what the aperture of a microscope ob-
ject should be, in his paper in Vol. LK XVI, p. 500, of the Transactions of the
Royal Society.—* Investigation of the Cause of that Indistinctness of Vision ,
which has been ascribed to the smallness of the Optic Pencils.’ I think,
however, it will be found that Sir W. had not obtained pencils of rays of such
extreme smallness as he supposed from a calculation of what the size of the
pencil should have been, according to the powers he obtaitied, for the power of a
compound microscope cannot be measured in the same manner ds that of a téle-
scope, by comparing the size of the ultimate pencil of rays after it has passed the
eye-glass with the diameter of the object-gluss or metal. Had Sir W. actually
measured the pencils with a dynameter instead of calculating their dimension,
he would have found them much larger than he supposed. In fact, all we
obtain from comparing the size of the pencil of rays which enters the eye with
the diameter of the object-glass in a microscope, is what thé power of a tele+

Dr. Goring on Miéroscopes. 207

Thave several much deeper made on this plan up to ;'5 inch—all
of which shew the parallel lines in question, and other equally
difficult objects,;—the deepest lenses have their apertures some~
what larger than this ratio, for the sake of the light, (for it appears
that you may increase this aperture, though you must not diminish
it, and yet see these objects, though the fog then becomes very
great and disagreeable; the colour also grows very apparent on
account of the largeness of the aperture relative to its focus.
Common microscopic object-glasses as we all know are sufficiently
achromatic with the small apertures, and the shallow eye-glass
of one inch focus usually employed, in which respect there is an
analogy between them and telescopes with object-glasses com-
posed of single lenses of small aperture, and a shallow eye-glass.
The achromatics only differ from them in carrying a larger aper=
ture witli a deeper eye-glass, which again have their limits, beyond
which the colour appears as before,

_ In Figs. VII, VIII, and 1X, are representations of some silver
cups for holding very deep single lenses intended to view opaque
objects, which, together with the object-glasses before-mentioned,
were executed for me by Mr. Tuther, optician, in High Holborn,
to whose politeness and skill I am indebted for being able to carry
my intentions into effect. It is generally supposed that single
lenses will shew objects perfectly clear and without fog, but this
is not the case unless their apertures are very small,—lenses of
as ao 5, and ;!,th of an inch focus require their apertures to be
so much reduced to shew opaque objects clearly, that it is scarcely
possible to see at all with them from the want of light. These
cups were contrived to remedy this defect as far as it is practi-

scope would be, having an object-glass of the same aperture with the microscopic
one with a focal length, equivalent to the distance between the object-gluss of the
microscope, and the focus of its eye-glass having its image magnified by the
said eye-glass. For example, I measured the power of a microscope in the
legitimate way with two similar micrometers, one on the stage, the other at
the field bar in the focus of the eye-glass—supposing the eye-glass of 1 inch
focus to have magnified six times, the power was 386, while the size of the
pencil at the eye-glass compared with the diameter of the object-glass was
merely as 2 to 6—the oue being 375 of an inch, the other y¢5-

Q2

208 Dr. Goring on Microscopes.

cable ;—their radius is only + of [an inch, their focus consequently
4, These condense light much more than the larger cups.com-
monly used, and illuminate much more powerfully. It is true
that they only enlighten a small portion of an object, but then we
can only see a very small portion with such deep lenses as they
are intended to hold; they are not so small but that they may be
made to receive and condense the whole of the light proceeding
from a bull’s-eye lens placed at a proper distance from them, and
in this way with no other light than that of a common candle, I
have been enabled to see well an opaque object with a compound
microscope, having an object-glass of only Aj inch focus set in
one of them, with only a moderate aperture. A lens of ;4, inch
set in this manner, used as a single lens, likewise shews opaque
objects in a manner which leaves nothing to be desired.

I must mention, however, that it is necessary for the stops
between which the lenses are placed to be very accurately made.
They should be turned out of a piece of solid brass, the external
one very thin, and the holes so correct as always to coincide with
each other when the stops are turned round; the apertures must
be quite free from burrs ; in addition to which the stops must be
so adjusted that the focus of the lens and that of the cup must
precisely correspond, otherwise the benefit of the cup is in a great
measure lost.- Fig. IX will carry 4 or 45 of an inch without any
stop at all, which is a great convenience, for the lens is in this
case close to the eye, and the field of view larger in consequence :
the stops for the deeper lenses are much shorter than they would
be with larger cups, (Figs. VII and VIII,) so the field is increased
in the same way, and the eye much less strained in using them
than it would be were the lens farther off from it. I have shewn
many individuals objects with the 4, inch lens not remarkable for
the strength of their eyes, who saw with perfect ease, and were not at
all conscious of the extreme smallness and depth of the lens they
were using. As single lenses are generally considered to be most
adapted for making discoveries in natural history, as being less
likely to create optical deceptions than compound magnifiers, I
imagine I am doing naturalists a service in putting them into a

Dr. Goring on Microscopes. 209

way of using very deep ones without destroying their eyes*. [
humbly recommend the contents of this paper to opticians, without
being at all ambitious to acquire the honour of teaching them
their own profession. I have the highest consideration for their
practical knowledge, and conceive that one ounce of it is worth a
ton weight of that of a mere theorist; at the same time I hope
they will accept of my apologies for pointing out a few circum-
stances to them, (certainly not of much importance,) which the
value of their time and the multiplicity of avocations of higher con~
sequence will not usually permit them to attend to. If what I
have written shall prove of no service to them, itis quite clear that
my labours have been utterly useless. Indeed, it is too much the
case that the researches of amateurs only terminate in discovering
something which was perfectly well known before, and which only
therefore serves to shew their own shallow acquaintance with the
subject, or in bringing forward something as an improvement
which has been tried and rejected long ago by those practically
versed in the mysteries of optics.

Art. IV.—Hints on the possibility of changing the Residence
of certain Fishes from salt water to freshu—By I. Mac
Cuxttocn, M.D., F.R.8., &c.

Iy the tenth volume of Tilloch’s Journal, there is a paper on the
means to be employed for multiplying fish, translated from one
which appeared in the Monzteur, by Monsieur Nouel, of Rouen.
Although the chief speculations of this writer, which are of a very

* They may, perhaps, also thank me for informing them that Mr. Cornelius
Varley, of Upper Thornhaugh-street, Bedford-square, (the inventor of the
graphic telescope,) worked the small lenses for me which I have described ;
they were polished on wax tools, the figure is as correct as that of any shallow
lenses, and their image will bear magnifying perfectly well. Mr. Varley and

“Mr. William Tulley of Islington, are the only individuals I know who can
make such deep lenses as they ought to be made.

210 Dr. Mac Culloch on the changing

interesting nature, concern the means of transferring the inhabi-
tants of fresh waters in one country, or those of certain lakes or
rivers, to others where they are not found, some hints are also
introduced respecting the possibility of rendering certain sea-fish in-
habitants of fresh waters. The whole paper is highly worthy of
attention ; but I am not aware thatit has been followed by any of the
practical trials recommended by the author, on which its economical
value must ultimately depend. An example in point which recently
came under my notice in Shetland, has induced me to examine the
subject with somewhat more care than the author of that memoir
seems to have bestowed on it, and to inquire more minutely into the
arguments on which the probability of success rests. The following
seem to be the only results which have been obtained, or were pre-
viously known with respect to that part of M. Nouel’s plan, which
relates to the cultivation of sea-fish in fresh water.

The plaice, Pleuronectes Platessa, as it appears, has been carried
from the North sea to the ponds of East Friesland, where it has
become established. The herring is said by Liancourt to frequent
the Potowmack, Hudson, Elk, and Delaware rivers; but it has not
appeared that the author’s project to take it from the Seine into
fresh-water ponds has been put into practice. The authority of
Twiss for the existence of this fish in the fresh water lakes of Ire-
land, is more than questionable, and M, Nouel is assuredly misin-
formed when he states that it is found in prodigious shoals in Loch
‘Lomond and Loch Eck in Scotland, both of them fresh inland
lakes. I know not how this author can have thus been misled,
unless he has mistaken some of the sea lochs for fresh-water lakes ;
though he could scarcely have confounded those he has named
with any of the western inlets. I shall hereafter, however, point
out a fact which renders his assertion possible; though he could not
have been acquainted with it, as it is not very long since it was
known, and has not been published in any work siioiglt to have
reached his hands.

It is also asserted in the same paper, that the salmon, in sual
has, in certain lakes, become naturalized, ‘‘ abandoning their erra-
tic taste, for a calm and settled life.” Whether such an experiment

the Residence of certain Fishes. 211

might not succeed, by forcibly transporting the salmon to lakes
from which they could not reach the sea, is yet to be tried; but
certainly there are not at present any salmon found inthe Scottish
lakes, except where they have the power of making their annual
migrations into salt water. That salmon are attached to the parti-
cular rivers where they have been spawned and bred, is believed by
all the fishermen; but this does not prove that they are naturalized
to those fresh waters, as they inyariably return to the sea after
haying deposited their spawn.

According to Pallas, the sturgeon, the sterlet, and some species
of salmon reside in the river Kama without ever descending to the
Caspian sea; and the authority of such a naturalist is perhaps suf=
ficient to establish this interesting fact.

These, then, are the whole of the proofs“which, in M. Nouel’s
paper, are adduced in support of this project ; it remains to be seen
by what other facts and reasonings its plausibility may be supported,
and an inducement offered to those who have it in their power, to
make such experiments as alone can establish it among those facts
in natural history which are capable of being applied to the uses
of man; to increasing the quantity, or adding to the accessible
variety of his food.

In the first place, it must be remarked, that the habits of many
sea-fish are, in this respect, so convertible, or so easily assimilated
to the requisite change, that a large portion of their time is passed
in fresh water. The common salmon, the grey salmon, and the
salmon trout, Salmo Salar, Salmo Eriox, and Salmo Trutta, are fa-
miliarly known to frequent rivers for the purpose of spawning; re-
turning to the sea when this operation has been performed. The
Salmo Migratorius leaves the lake Baikal for the same season; and,
with us, the 8. Lavaretus, or Gwiniad, and the S. Eperlanus or
smelt, also quit the sea; ascending rivers at the spawning season,
as does the Salmo Autumnalis, an inhabitant of the frozen ocean.

Now though M. Nouel is wrong in saying that the salmon
is found in the Scottish lakes excluded from access to the sea,
it is a fact that the salmon trout, or sea trout, as it is called in Scot-
land, is now a permanent resident in a fresh-water lake in the

212 Dr. Mac Culloch on the changing

island of Lismore, and without the powerof leaving it or reaching’ the
sea. There, it has been known fora long course of years, perfectly
reconciled to its prison, and propagating without any apparent dif-
ficulty. If this fish, whose annual necessity for returning to the
sea is the same as that of the common salmon, has thus easily be-
come naturalized, there is little reason to doubt that the same expe-
riment would succeed with the salmon itself. The fishermen ob-
ject to that opinion, that this fish becomes meagre and diseased by
its residence in fresh waters, and is compelled to go to the sea to re-
cover itself. But we need not feel much concern respecting their
philosophy; while they forget at the same time that it is the opera-
tion of spawning by which the fish is injured, and that this conse-
quence happens alike to sea-fish, from the same causes. It remains
to be proved that the salmon would not recover itself in fresh-
waters, as the sea trout does in Lismore; and this is the experi-
ment which is to be tried before we are entitled to pronounce a ne-=
gative. To render the salmon’a permanent resident of the fresh-
water lakes of Scotland, would unquestionably be a great gain ; and
that this has not been tried, often as it has been urged on those who
have the means, is only an additional proof of the plodding incredu-
lity and obstinacy of those who are averse to all innovation because
it is innovation, and who believe that they have themselves attained
the summit of all possible knowledge.

With respect to the smelt, its delicacy would render it a very de-
sirable acquisition in our ponds, while its size would probably
cause it to find an easy supply of food, and its facility of living for
a time in fresh water render its naturalizationeasy. I accordingly
caused some trials to be made for this purpose: they did not how-
ever succeed, but the experimenter considered that they were not
fairly conducted, as the fish had been injured in the transportation.
It is obvious that in every trial of this nature great attention to this
part of the operation must be requisite.

Since this, a perfect experiment to this effect has been made by
Colonel Meynell, in Yorkshire. The fish have lived three years,
and it is understood that they have propagated abundantly. They
were not affected by freezing, as the whole pond, which contained

the Residence of certain Fishes. 213

about three acres, was so frozen over as to admit of skating. As
to their quality, it was considered by the fishermen of the Tees,
by whom the pond was drawn, that they had never seen “a finer
lot of Smelts ;” so that in this case there was no loss of flavour or
qua ity.

The common pike, Esox Lucius, which is an inhabitant of fresh
lakes with us, is also found in the Caspian sea; proving that this
animal among others is indifferent to the quality of the water which it
inhabits, and, in this case, permanently so.

It seems to be unquestionable, that in the Dee and some other
Scottish rivers, the common eel, Murena Anguilla, migrates an-
nually to the sea, wherever it has the power of reaching it ; return-
ing again to the rivers and lakes which it has generally been sup-
posed permanently to inhabit. The conger eel, Mureena Conger,
which is an inhabitant of the sea, in general, also frequents rivers ;
so that, of this genus, there are two at least of which the ence
is occasionally convertible.

The Gadus Callarias, or torsk, is also known to enter the mouths
of rivers, so that it can reside at least for a time in fresh waters
without injury; but it is not known to remain in them permanently.
That the Gadus Morhua, or common cod, can reside permanently
in fresh water, is proved in Shetland. In the mainland, as it is
termed, of that group, the inlet called Stromness-voe communicates
with an inland fresh-water lake by a channel so narrow as to ad-
mit of a rude bridge by which the opposite shores are connected.
In this fresh water, cod are frequently taken ; and that the water is
perfectly fresh is certain; as the tide is never sufficient to pass the
strait of communication, merely damming the fresh water till the
ebb again commences. The inhabitants seem to entertain no
doubt that the cod remains there for a considerable time; but the
subject not having particularly interested them, it remains to be
discovered whether their residence is permanent or occasional, or
whether they spawn there. If they reside there, even for any length
of time, it is probable that this water contains other sea-fishes, by
which they are tempted, unless they feed on trout; but I could not
discoyer that any others had been found.

214 Dr. Mac Culloch on the changing

The Gadus Barbatus, or whiting, and the Tricirratus, or rockling,
occur in abundance in those Highland sea-lochs where the water is
at times perfectly fresh, from the magnitude of the riversin rainy sea~
sons; not quitting their haunts even when it is deeply tinged by the
colour derived from peat. From their permanence in those situa-
ations, and from being taken of all sizes, they probably spawn
there; and, if so, they offer, like the common river flounder and the
pike, perfect examples of the permanent convertibility of the habits
of these species.

The Cottus Quadricornis, a native of the Baltic, also ascends
rivers, as does the GasterosteusPungitius, or stickleback, in our own
country. The Pleuronectes Platessa, or plaice, as has already been
observed, is naturalized to fresh water in East Friesland: and the
P. Flessus, or common flounder, is. well known to be permanent
in the Thames and other rivers, far within the fresh water, although
equally a salt-water fish. The P. Roseus has also been taken in the
Thames. Iam further informed that a sole was kept in a fresh-
water pond in a garden, by a person whose name I need not quote,
for a great many years ; and if the plaice and flounder can be so
naturalized, it is not unlikely that this would prove true of the
whole genus.

Although the mackerel is rare in Scotland, it is sometimes taken
in the lochs of the western highlands, where the water, from the
entrance of rivers, is nearly or absolutely fresh ; a proof at least,
as in many other fishes, that whatever aversion they may have to
residing permanently in fresh water, whether from the want of food
or for other reasons unknown to us, they experience no difficulty
in respiring in it.

The Mugil Cephalus, or mullet, which is a sea-fish, not only
ascends rivers, but has been introduced and detained in ponds;
offering another example, like the plaice, of the possibility of per-
manently naturalizing a sea-fish to fresh water. This fish does not
necessarily spawn in rivers; since, in England, it performs this
operation on the sandy and muddy shores of the sea. Yet, in
Asia minor, it appears that it always spawns in the rivers, ascending
the Sturmus, the Meander, and others for this purpose, and pro-

the Residence of certain Fishes. 215

dueing the Botargo so well known in the market. This is a valu-
ble fact in the question under consideration; as it proves that, in
the matter of spawning, fishes are not tied down to those fixed
and necessary habits which has been commonly supposed.

As the case of the naturalization of the grey mullet is particularly
interesting, and is at the same time unknown, except to the few in-
dividuals who caused the experiment to be made at random, it de-
serves a more particular description; since it offers, together with
the instance of the cod in Shetland, another of those facts which
have come within my own knowledge.

This experiment is, at the same time, perfect, as much so as that
of the plaice in East Friesland ; and it holds out therefore a tempt-
ing prospect of success in other cases where no trials, either from
accident or design, have yet been made.

_ About ten years ago a number of the grey mullet, about the size
of the finger, were placed in a pond of three acres in area, in
Guernsey; the water being perfectly fresh. They haye since in-
creased in size, as well as in numbers; although, from the small
extent of this pond, it is evident that their ultimate increase cannot
be very considerable. Fish of four pounds in weight have since
been taken from this pond, so that in this respect as well as in their
propagation, the experiment is complete and perfectly satisfactory.
It isremarked that they are much fatter than those taken in sea-
water in their natural state, but that the flavour is not so good.

From this pond a number of small fish were afterwards taken
for the purpose of stocking a smaller one. These continued to
grow and thrive for about three years; when unfortunately, the oc-
currence of a severe frost, during which the water was closed up
many days, destroyed them,

In this case itis evident that nothing is wanting to the establish-
ment of the fact in question with regard to the grey mullet: and it
may safely therefore be named as one of the fish which ‘may with-
‘out difficulty be naturalized to fresh water, and made use of to in-
crease the accessible variety of our food or luxury, in places where
fresh waters abound, and which are far removed from the sea.

' This experiment is fully confirmed by the practice of the

216 Dr. Mac Culloch on the changing

Sicilians, In the Lake Biviere, this fish is cultivated for the pur-
pose of food, and because its quality is thus found to be improved.
It is an important circumstance also, that the water is here such
as would be supposed peculiarly offensive to fishes taken from the
sea; as it lies ina marshy plain, and is such that the extent of
the lake is twice as great in winter as in summer. Such water
must be nearly putrid; and therefore the Mullet at least would
probably live and thrive in any ditch or pond.

As its quality is thus also found to be improved, it is plain
that the report respecting the deterioration of the Guernsey Mul-
lets is, at best, doubtful ; while it is equally probable, from this
case, as well as that of Colonel Meynell’s Smelts, that the general
effect would be to improve, instead of injuring, the flavour of the
sea-fishes in general.

Though here somewhat out of place, I may also notice,
that Lobsters and Crabs are introduced into the same lake for
similar purposes, where they are not only preserved but improve
in flavour. It had been concluded, in England, that these animals
could not be so cultivated, because an experiment made by Sir
Charles Monck failed. We must probably attribute this to some
accident ; as the Sicilian practice is of long standing, and has been
confirmed through an unknown course of years. As to the im-
provement of the flavour of the Lobsters and Crabs in this case,
it is distinctly stated, and it confirms the general presumption that
this would commonly be the result ; while another confirmation is
found in the fact that Oysters acquire their good qualities only
by residence in fresh water. Thus the Oysters of Portsmouth
and elsewhere are transferred to Colchester; and if those which
are called ‘“‘ Natives,” possess good qualities, it is because they
are produced at the estuaries of rivers, where the water is con~
siderably fresh, as is the case with those of Milton. In’a similar
way, Cockles and Muscles are perfectly worthless, except in
analogous situations, as is equally the case with Periwinkles ;
and it is known to every one, that the best Shrimps are those
which are taken on the fresh and muddy shores of England.

The Clupea Sprattus, or sprat,is well known to be taken in the fresh

the Residence of certain Fishes. 217

water of the Thames; although it is not ascertained whether it re-
mains for any length of time out of the salt or brackish water. The
C. Alosa, however, or shad, ascends rivers to spawn in the spring,
like the salmon, returning in the autumn ; and its spawn, the white-
bait of London epicures, is well known to be taken in the fresh
water. It is probable therefore that it spawns there, as the salmon
does; and hence also, were this fish worth the experiment, it
might probably be naturalized to lakes and ponds. This seems
peculiarly plausible in the case of all the sea-fish which spawn in
fresh waters; because this is one of the natural operations which
we should conceive it 2 priori, most difficult to counteract.

I already noticed that the best known fish of this genus, the
herring, was found in the fresh American rivers. And though I
was obliged to contradict M. Nouel respecting its existence in
Loch Lomond, I may here say that it has been found at different
times in Loch Dhu, a fresh water lake in Argyllshire, near Loch
Fyne. In this case, it appears to have been introduced during a
flood, through the small river by which this piece of water commu-
nicates with the sea; being afterwards confined by the subsidence
of the water, so as to have remained imprisoned for many years. It
does not seem however to have been ascertained whether or not it
propagated in the lake; so that this natural experiment still re-
mains incomplete for want of observation. This however is a
trial so easily repeated, that nothing probably has prevented it, but
that ignorance or prejudice on this subject which it is the main ob-
ject of this paper to remove, by holding out reasons for probable
success.

The Crucian, Cyprinus Carassius, the Bleak, C. Alburnus, the
roach, C. Rutilus, the bream, C. Brama, the C. Idus, C. Nasus, C.
Aspius, and C, Ballerus, like the pike, seem to inhabit the Caspian
sea as well as the fresh waters and ponds of Europe; offering
other instances of perfect and permanent indifference to the nature
of the waters in which they exist.

The Chaleoides, in the same genus, migrates annually from the
same salt lake to the rivers that run into it; and the C, Aphya

218 Dr. Mac Culloch on the changing

seems to inhabit indifferently the sea shores and the mouths of the
neighbouring rivers.

The Cyclopterus Liparis has also been deserve to ascend from
the sea into fresh waters; and the same fact is familiar with respect
to the sturgeon, the common lamprey, and the lesser lamprey, or
Petromyzon Fluviatilis.

Lastly, the Delphinus Leucas, or white whale, is known to ascend
the fresh-water rivers of Northern America; but as this animal
breathes air, it does not, in that point at least, coincide with the
true fishes, which respire water. The appearance of this species
of whale seems to have been the chief evidence by which Hearne
and Mackenzie attempted to prove that they had reached the sea
in their respective expeditions. It is known to ascend the Hudson
to adistance of 100 miles and more, above the salt water, and is
taken by an established fishery high up in some of the fresh rivers
of Hudson’s-bay.

Here then is a large body of evidence, derived not only
from the occasional, but from the permanent, residence of
many sea-fish in fresh waters, and, on the contrary, of some fresh-
water fish in salt lakes, to prove the existence, or possibility, of
these convertible habits, at least in those species. But it will be
convenient to subdivide the considerations which arise out of this
subject, as they affect those functions in fish which, as far as this
question is concerned, must be considered as of a vital or essential
nature; either as they regard the life and health of the individual,
or the continuation of the species.

The first of these is the act of respiration. The first doubt na-
turally arising on this subject is, whether salt-water fish can with
impunity breathe fresh water, and the contrary. From the great
number of the sea-fish which, either systematically or occasionally,
visit fresh water without inconvenience, it is fair to conclude that
the latter in no way disagrees with the function of respiration in
them. A much stronger confirmation of this is afforded by the
facility with which the plaice, mullet, and flounder haye been per-
manently naturalized to fresh water; and by the fact that so many

7

the Residence of certain Fishes. 219

others which are described in the preceding catalogue, seem by
nature to inhabit both indifferently. It remains indeed to be proved
that any fresh-water species now known as limited to rivers and
lakes, can be permanently confined to the sea; but this is a point
which can obviously never be determined.

A species of argument might be derived, on this subject, from
the probable state of the earth at former distant periods, and from
that which has probably been the original condition of many inland
lakes besides the Caspian. It is probable that many such lakes
were portions of the salt ocean, and that they have been rendered
fresh since their separation from it, by the effects of the rivers flow-
ing into them. In this case, the fish which these contain were
once sea-fish; and thus perhaps we may account for the double
existénce of the pike and of those Cyprini above described, in
the salt waters of the Caspian and in the fresh lakes of other inland
districts. But I will not here lay much stress on this reasoning.
It is evident at least, from the preceding remarks, that a change
of the medium of respiration is not injurious or poisonous to all
those fish which even incidentally pass into fresh waters from the
Sea, as this effect, if any, ought to be immediate, or at least speedy.
If so many species can bear that change in the medium of respira-
tion, it is not unlikely that the whole might, as the general struc-
ture of the respiratory organ is the same in all; and it is not
therefore likely that this function will be the cause of any great
obstruction in attempts to change permanently the residence of
fishes from one variety of water to another.

The next important function to be considered is that of nutrition,
or the probability that food may be found or provided for those
sea-fish which any projects of naturalizing them in fresh waters,
may confine to inland lakes. We are so little acquainted with the
food of many fishes, that it is not possible to throw much light on
this subject ; but it is probable that the most important and insur-
mountable obstacle will be found here. Of many species, it seems
to be ascertained that they feed on marine vegetables. Others,
like the mullet, are known to plough the sand in search of lum-
brici; probably also, of the spawn of other fishes. Some species

220 Dr. Mac Culloch on the changing

seem to be especially provided with the means and the desire of
feeding on shell-fish ; others on crabs or the crustaceous insects ;
while the northern whale, by an arrangement which must always
appear extraordinary, is furnished only with the power of subsist-
ing on animals so small as to be imperceptible, to its sense of sight
at least, and which, in the scale of dimensions, lie almost at the
opposite extreme to its enormous bulk. Many fish, like the cod,
are known to be omnivorous ; and of others, it appears probable
that they feed solely on the multitudinous tribes of vermes and in-
sects which crowd the waters. It is probable that, with respect
to a great number of species, they live in succession on each other,
if that expression can be used with propriety ; or that, in the my-
riads of animals of singular and imperfect construction, and often
of microscopic minuteness, which crowd the ocean to a degree
that almost surpasses credibility, provision is made for the wants,
in succession, of all those which successively exceed each other
in size, voracity, or activity.

If we were to judge from what is within our reach with respect
to many fishes, we should be tempted fo imagine that they can
live for long periods, even without food, or with a very small pro-
portion, Thus the cod, one of the most voracious, has been kept
in perfect condition in Orkney, confined in sea-ponds for three
months and more; although no visible animal was admitted with
the water which the tide daily brought to its prison. During the
whole residence of the salmon in fresh waters, which often extends
to a considerable period, it seems to exist with little food ; since the
few winged insects at which it occasionally rises, can afford no
effectual nutrition to an animal of such bulk and activity. The
state of the common ornamental gold-fish confined in water-
glasses, is equally remarkable ; but it is unnecessary to prolong
the enumeration of facts which, however difficult to explain, haye
ong been familiar to those conversant with the habits of fishes.

But whatever we may doubt respecting the nature or the neces-
sary quantity of food for fishes, it must be evident that no perma-
nent naturalization of many of them, at least, can be expected,
unless the new situation is such as to provide them with a suffi-

the Residence of certain Fishes. 231

cient supply of food. In many cases, perhaps, we may judge for
them; and if the proprietor of a Highland lake chooses to eat cod
rather than pike, at the expense of a proportion of his perch and
trout, and can persuade them to live in his fresh water, it is
probable that they will not have to lament. the want of food.

In any case, our ignorance on this subject need not be a bar in
the way of any experiment on this kind of naturalization. So
many species find their food without our knowing the means or the
materials, that we may safely trust to their wants and their powers.
Besides, as the enormous reproduction of all these tribes is evi-
dently in part destined for the general support in succession of all
those of which they are the prey, it is evident that by increasing
the population and the variety in any of these watery kingdoms,
we increase the means of mutual support. The smaller feed on
that which the larger could not find or use; and thus they maintain
the existence of their superiors, who, in return, are destined per~
haps to maintain them with their own ova or offspring. If again,
practically, the plaice and the flounder, natives of the sea, have
found the means of permanently feeding themselves in fresh waters,
it is not unlikely that many others may there. find food unknown
to us, and, for want of trial, unknown at present even to them.

But there is no difficulty in feeding tem, should that prove ne-
cessary. This was a common practice with the Romans; and
those who choose to turn to Varro or Columella, may see records
of the immense sums which were expended by the Romans in feed-
ing the fish in their vivaria; as they may also see, from the enor-
mous prices paid by Cesar, Lucullus, and others, to what an-ex-
tent the practice of keeping fish-ponds was carried, and how im-
portant a branch of rural economy this was considered. The con~
sequence attached to fishes by this people is apparent everywhere ;
and no one need be told of the celebrated Senatusconsultum held
on aturbot, or of the fishes which, Martial tells us, came to their
owner’s call and licked his hands. If, in our own rural. economy,
it is found profitable to feed pigs and fowls, it would not be less so
to feed fish, nor are these tribes, apparently, less omnivorous than
hogs.

Vor. VII. R

222 Dr. Mac Culloch on the Changing

The last of the important functions of fishes likely to be an impe-
diment to this attempt, is their reproduction, or the act of spawn-
ing; or rather, the circumstances necessary to ensure the vivifica-
tion of the ova. The instincts, as they are called, or the peculiar
habits of many fish in this important affair, seem often to be as ob-
stinate as they are peculiar. This is notorious in the case of the
salmon; which must not only deposit the ova in a river, but ina
remote part of it, and even in the very stream in which it has itself
been produced. Many fishes deposit their eggs only on shallow
shores, although they inhabit the deep seas, Some frequent the es-
tuaries of rivers for that purpose, others select mud, a third set sand,
and others again the crevices of rocks, Yet as this part of the
economy of fishes is a matter of necessity, it only remains to con-
sider whether, being deprived of these conveniences to which they
are instinctively addicted, they would not soon find it expedient to
abandon them, and to adopt those alone which were within their
reach. In this respect, the habits of the land animals with which
we are acquainted, have been found susceptible of temporary, and
even of permanent changes. Little acquainted as we are with the
intellectual powers of fishes, or with the variety of character and
capacity for education which may exist among them, it is bad rea=
soning to presume that they are incapable of cultivation or change
of habits, and that their sole talents are to catch, and their sole oc-
cupation to eat, each other,

Presurning, therefore that the ova must, as a matter of necessity,
be deposited somewhere, it may be observed that inland lakes pre=
sent all the varieties of bottom which are found in the sea, They
receive rivers, have muddy bottoms, sandy and gravelly shores, and
intricate rocky creeks; and, in some or other of these places, every
fish may find a situation for its ova, more or less consonant to its
natural habits. Nor is there any reason to suppose that where the
perent lives, its ofispring could not be vivified ; since the vitality of
the ova is far less likely to be affected by a change from salt water
to fresh, than the complicated functions of the living and full grown
animal, In a practical view, the power of continuing the species -
under such a change, is proved by the facts already cited with ree

the Residence of certain Fishes. 223

spect to the plaice, mullet, and flounder; and it is only to be regret-
ted that no further evidence of this satisfactory nature can be
adduced in favour of this reasoning. The double residence, how=
ever, of the pike, and of the various Cyprini, already more than
once quoted, offers a complete argument in favour of the convertible
habits of these species at least, in the business of reproduction as in
that of food.

Supposing now that, at least the probability of all these reason=
ings is admitted, it only remains to put these speculations to the
test of more extensive experiments. Nature has executed two, per-
haps more; art, in the plaice, the smelt, and the mullet, has carried
three more into effect. There appears no practical difficulty attending
it ; as fish can be transported alive in water, for a great length oftime,
and to great distances, without inconvenience. If Shetland were differ-
ently constituted with respect to the distribution ofits population and
the residence of its proprietors, a very satisfactory and easy experi=
ment, on the cod at least, might be made in Stromness Voe. It
would only be necessary to shut up the very narrow opening by
which it communicates with the fresh water, by means of a grating,
and time alone would soon determine the question. Should this
paper meet the eyes of a body of proprietors distinguished for their
intelligence and activity, it may perhaps iuduce him in whose power
it lies, to make this easy experiment. Nor could there, in this
place, as in some other situations in Scotland, be any difficulty in
extending the same trials to other species of fish. But I need not
dwell on this part of a subject which every one is competent to un=
derstand, but which not many have the means of submitting to the
test of experiment.

On the transportation of fish, I must remark thatit is not attended
with so much difficulty as is commonly imagined, and that the fault
generally has lain with those who have made the attempts. Many
' fish are exceedingly tolerant of being out of water fora time. The
carp is keptin nets, in cellars, and fed thus in Holland. Minnows
will live for months, crowded in a quart pot, with as little water as
they can barely stir in, or in absolute contact. The whole of the
flat fish are similarly tenacious of life; as are the conger, the gur-

R 2

224 Dr. Mac Culloch on the Changing

nard tribe, the dog-fishes, and many more which I need not enu-
merate. The fault of those who have attempted the transportation,
has been to take fishes which had been long hooked, dragging upon
Long Lines, or entangled for a night or more in a trammel net.
Owing to the peculiar distribution of the arteries in fishes, their
muscular power is speedily exhausted by violent exertion; and
hence they are literally killed, or nearly so, before they are taken
out of the water insuch cases; an effect which, in the case of salmon
and trout taken by a fly, is vulgarly called drowning. This must
be avoided ; and it is well known that when cod are taken by hand
lines, and thence transferred to the wells of the fishing boats, they
always live, unless the gills or stomach have been much injured by
the hook.

. As far as this may be considered a question of economy or utt-
lity, it is not necessary to say much. It may perhaps, abstractedly,
be deemed of little consequence whether an inhabitant of Germany
is condemned to eat roach and gudgeon, or to regale on whiting and
smelts ; or whether, in a Highland lake, john-dory is to be substi-
tuted for pike, and turbot for par. But all the improvements in
the details of human life may, if we please, {be measured by
the same rule. We have naturalized and domesticated the wild
animals that walk and fly, to be our fellow-labourers, our compa-
nions, our servants in the chase, our amusement, and our food.
Nature has given us crabs and sloes, which we have converted. by
our industry and perseverance into golden pippins and green gages,
It is not an illaudable pursuit to apply to the uses of man all {those
bounties which nature has spread around him; but on the posses-
sion and perfect enjoyment of which this law has been stamped,
that without labour and industry, they shall not be attained.

. Yet while on this question of economy, it may not be improper
to suggest a few doubts respecting the prudence of that conduct
which, in this country, neglects the sources of rural profit to be
derived from cultivating the produce of its. fresh waters.. In
France, it is said that the value of an acre of water is equal to that
of an acre of land; and these ponds are rented by great fishermen,
or fishmongers, who adapt these systems of fishing their farms in

the Residence of certain Fishes. 225

such a manner as to ensure the greatest possible permanent stock of
fish ; removing the superfluous produce, which would otherwise
be devoured or die, without injuring the future population, and.
thus procuring a constant and regular supply in the season, with=
out the risk of exhaustion.

In Germany, it is well known that the cultivation of carp and
other fresh-water fish is a regular object of attention; and although
the proximity of the sea may cause us to treat with contempt the
painful efforts of our neighbours to do that for themselves which
nature has so bountifully done for us, it is assuredly not unworthy,
the attention of the proprietors of inland counties in Britain, to at-
tempt to produce from them, either rent or profit. Under the pre~
sent system, the fresh waters of this country are of little use but
to furnish amusement to the sectaries of good Isaac Walton, and
occupation to those who create flies of which no entomologist ever
dreamed. Amusement would not be excluded by profit. If, too,
it is said, as it well may be, that, as an article of food, the
fresh-water fish are inferior to those of the sea, it must also be re=
membered that variety, no less than excellence, is one of the great
resources, as it is one of the main pursuits, of the noble science of
gastronomy.

But, to be more serious, the quantity of fresh waters existing in
Britain is so considerable, as, with the exception of Switzerland,
to exceed those of any country in Europe. From these, no profit
whatever is derived. A Scottish lake, under a regular system of
fishing and care, might probably far exceed in value the miserable
tract of bog and rock by which itis enclosed. The canals of this
country occupy a respectable space, and might, like ponds, be
stored with fish, to the probable advantage of the proprietors no
less than of the community. Even the rivers are unproductive,
with the solitary exception of salmon, and of eels; since the
quantity of other fresh-water fish brought to market is far too in-
significant to be an object of attention in a case like this where so
much more might be effected.

The objection to fishing on canals is the injury which may be
done to the banks, That, if it really exists, would cease whenevey

226 Dr. Mac Culloch on the Changing

the fishery should become a farm in the hands of a lessee. In all
these cases it is merely supposed that, as in France and Germany,
the object should be the cultivation of fresh-water fish. But if as
the views held out in this paper attempt to prove, sea fish
can be naturalized in canals, lakes, ponds, and rivers, it is not
unlikely that the sources of profit might be materially imereased.
Experience would in a certain time teach us to know the fish
that would live together most usefully for ourselves, that would
rather contribute to each other’s support and to ours, than to their
own mutual extermination. As yet, this is a subject little known,
because it has been too much the usage to suppose, that as man
cannot live in the same element witha fish, he has no chance of
acquiring a knowledge of its habits and pursuits.

The lakes of Scotland, of the North of England, and of Wales,
offer particular facilities for the naturalization of sea fish, on
account of the small distance at which most of them lie from the
sea, and of the consequent facility of transporting these creatures in
a living state. Should such a project ever be carried into effect,
the good consequences are obvious. The facility of commanding
a supply of fish would be increased; while that would also become
certain, since it would no longer depend on weather, which so
often interferes with the regularity of the sea fishery and of the
market. The demand and supply might then also be more ac-
curately balanced, as it'is in all parallel cases when the steady
price of domestic animals for food, is compared with that of those
which are the produce only of chance or contingency. It is an
unquestionable fact that the produce of fish for consumption may
be much increased by the very act of fishing them; or that a
certain proportion may be regularly taken away for use, without
diminishing this subaqueous population. It is thus that a profit
is made by waters which in their natural state yield no supply for
man. Nor, in the sea, is the apparent supply for our uses, ever
diminished by any quantity which we can consume, provided that,
in some peculiar cases, care is taken not to destroy the ova, or
the fish under a certain size. How little attention has been paid
to this subject, in sea fishing, is proved by arecent Act of Parlia~

the Residence of certain Fishes. 227

ment regulating the use of trawl nets in Torbay, and hy other regula-
tions of less value, which have occasionally been made for similar
purposes.

In the cultivation of fish in fresh waters., the whole management
becomes so completely under our command, that there would be
no difficulty in framing such regulations as increase of knowledge
would soon suggest, and as private interest would follow, or that
of the public enforce.

In what precise manner the regularity of fishing increases the
supply, or at least does not diminish the production, has not, been
clearly ascertained. That the several species eat each other's ova
and young, and even their own, is very well established. Many
devour each other, even at full growth, and it is not unlikely that
many also die of disease or want of food. _ In such cases the steady
removal of the superfluous part of the population cannot check its
increase. If all the Turks and Egyptians who are to die of the
plague next year, were to be devoured by crocodiles, there would
be a certain quantity of food gained, and every thing would go on
just as before. The empire would not have been a bit less
populous or prosperous if the Huns and the Ostrogoths had eaten
each other instead of strewing their own bones and those of their
antagonists on the banks of the Dauube, or the plains of the
Campagna.

_ Respecting the species which might probably succeed in fresh
water, it is not possible to offer any very rational conjectures.
It is probable that they might most effectually be sought among
those genera of which some species are already known to be
versatile in their habits, In those genera of animals at least which
- are natural and not artificial, there are considerable resemblances
among the habits and pursuits of the different species. Thus it
is not very improbable that as the plaice, the flounder and the mullet,
have been naturalized to fresh water, the whole of the fishes of
analogous habits, and particularly those of the genus Pleuronectes,
might be habituated to inland lakes. The turbot and the sole would
be very desirable objects of cultivation, If different species of
Gadus have been shown to be at least indifferent to the quality of

228 Dr. Mac Culloch-on the Changing

the water into which they enter, the whiting as well-as the cod
might possibly learn to inhabit our lakes or rivers, and thus
become among the most accessible as it is among the most deli-
cate of fishes. If the smelt could be naturalized in ponds,
as I have here rendered more than probable, it would, from
the esteem in which it is held, be a peculiarly desirable acqui-
sition. The hints contained in this paper may possibly in-
duce others, who have the means in their power, to assist in the
execution of a set of trials which can succeed only in the hands of
many, and which must necessarily be the work of time.

It has been suggested that as the flavour of fresh-water fish is
far inferior to that of the marine species, the effect of naturaliza-
tion would be to diminish their value as articles of food. This
does not absolutely follow, although it may be thought probable from
the case of the mullet above-mentioned, and by the fact that the
flavour of the salmon is constantly diminishing from the time it has
quitted the sea. If such should prove to be the case, it might
indeed diminish the value of the acquisition, but it would not
therefore destroy it; nor is it likely that a smelt would ever sink
to the scale of a gudgeon, or a whiting to that of a roach.

I have already shewn, however, that this deterioration of quality,
so far from being probable, is not at all likely to occur ; since with
this single exception, supposed to have occurred in Guernsey, and
which is probably the report of prejudice, the flavour is really im-
proved in all the cases where the experiment has been fairly tried ;
and since the transportation, in Sicily, is made with this very object
and no other. At any rate, let the trials be made before any
such condemnatory judgment is passed.

I will only further remark here, that there is no very good reason
why the turtle should not be naturalized. What an acquisition
this would be, it may be left to the Court of Aldermen to decide.
The animals of hot climates, that live in air, have been so; and
and why the submarine, or amphibious ones should not equally
admit of this change of habits, I know not, and nobody else does.
The turtle might take its place alongside of the peacock and the
pintado, and with his fellow turtles of the land; while, if he chose

the Residence of certain Fishes. 229

to hybernate, he might find a dormitory in Loch Lomond or clse-
where, to pass the chilling hours of a Highland winter. And the
change would be less than in the case of the land animals; since
there is not such a difference of temperature in the one case as in
the other.

While on this subject, it will not be out of place to mention a
parallel object of economy, far less known than it merits, and
indeed little known out of Scotland, where it has been practised,
although in a very limited manner, for many years. This is the
preservation of sea fish in salt-water ponds. There are three of
these in Scotland ; one in Galloway, another in Fife, and the third
in Orkney. In these, even cod are known to live for many months,
and to increase in size, without any loss of quality, and without
any other food than that, imperceptible to us, which is brought by
the daily influx of the sea, In the pond in Galloway, some in-
dividual cod have been living for many years, so as to have be-
come tame, if such a word may be applied to a fish, feeding, like
hogs, out of a trough when introduced with a supply of food.

This practice is so obvious an extension, as it is an improvement,
of the expedient of using well-boats, as to afford cause of surprise
that it has not been adopted by those who are interested. Motives
of interest in the proprietors would shortly become matter of ad-
vantage to the consumers; and the unsteadiness of a fish-market,
no unimportant object of municipal attention, even in London,
would cease to be a subject of complaint,

The Romans, who seem to haye far exceeded us in all that
relates to eating, as they did in a few other matters, were well
acquainted with this practice ; and the history of their Vivaria has
descended to us, with much more that relates to their rural
economy, of which this formed a distinguished branch. Colu-
mella says, decidedly, that they transported the spawn of various
sea fishes to the different fresh-water lakes round Rome, ‘ marinis
seminibus implebant,” and that this was a regular trade with the
early agriculturists of the rustic Republic, before the rich and lux-
urious took the keeping of artificial Vivaria into their own
hands, He mentions the Mugil, which is probably our mule

230 Dr. Mac Culloch on the Changing

let, together with “ lupos, auratasque,” two fishes of which
we are not now able with certainty to assign the names.
He farther alludes to others which he has not named, as
being “ dulcis aque tolerantia.” He then passes from the subject,
as of too familiar a nature to require a more detailed notice;
a stronger proof than even his enumeration would have been,
of the facts which I have thus attempted to support from his au=
thority, and of the established existence of a practice which we
havelost, and appear, very strangely, to be unwilling torevive. But I
must refer your readers to the original, for the whole of this
curious chapter, as the translation of it would inconveniently
prolong this paper.

The merely temporary naturalization to our lakes and ponds in
the case of sea fish, would be no light acquisition to the gastrono=
mer who might desire to have turbot before the season, or to
reserve it at five shillings. for consumption, when the price has
risen to three guineas. If the cod chooses to live in the fresh
lake of Stromness-voe, there is no reason why we should not keep
them in our own gardens till the day of giving a dinner comes
round, or why Mr. Groves should not render the Serpentine a park
for surmullets, instead of allowing it to be consigned to frogs and
tadpoles. It is tobe hoped that the Fishmongers’ Company will
take these matters to heart, as in duty bound; and that, in the
progress of perfectibility, even the odious canal in St. James’s
Park may become a repository of turtles, instead of what it now is,
a Stygian nursery of Malaria and his black host.

There is a subsidiary question arising out of these speculations
respecting the convertibility of the habits of marine animals, highly
interesting to geology, and on which it will not be out of place to
say a few words, although unfortunately not much solid informa-
tioncan be procured respecting it. This relates to the power
which many, perhaps all of the vermes inhabiting shells, possess
of residing indifferently in fresh or in salt water.

It is well known to geologists that with respect to many, if not
all of those deposits supposed to have been formed, like that of
Paris and of England, under fresh water, the question mainly rests

the Residence of certain Fishes. 231

on this, namely, whether the shells now supposed, from certain
analogies and peculiarities of structure, to have been inhabitants
of fresh-water lakes, may not have equally existed in salt lakes,
or even in the sea. Some experiments towards the elucidation of
this subject have been instituted in France; but I need not detail
them, as they must be fresh in the recollection of all the readers
of this Journal. It has also been recently. ascertained by M.
Freminville, thet in the gulf of Livonia, the shell fish which
usually inhabit the sea, and those which belong to fresh waters,
are found living together in the same places. While these con-
firm the general presumption which forms the basis of this come
munication, their general probability is also strengthened by that
analogy. A few facts of common occurrence on our own shores,
seem to add additional weight to the opinion that the testaceous
fishes in general are not rigidly limited to one kind of water, but
are capable of living in both.

On our sea coasts, the common muscle is invariably larger and
fatter at the entrance of fresh-water streams into the sea, par
ticularly if these bring down mud, and in these places the water is
scarcely salt; yet they live also and propagate in abundance on
shores which receive no fresh water. The oyster is transported
from the sea to brackish water, where it also, not only lives, but
improves in condition. In the same manner the common cockle
inhabits indifferently the muddy sand-banks near the exstuaries
of rivers, which are always soaked with fresh water, and those
sandy or half muddy shores where no such water isfound. These
are by no means the whole of the instances which might be enu-
merated in support of an opinion, of which the determination is
so important in the present state of geological science; but as this
subject is too important to pass lightly over, and as the bounds
of this communication are already exceeded, I shall leave it to
those who may have the means and the inclination to examine it
in greater detail. I will only add, that the same considerations
will lead to similar doubts, where it has been attempted by geolo-
gists to determine the nature of strata, as to their marine or fresh
water origin, by that of the remains of fishes found in them.

232 Mr. Cooper’s Lamp Furnace,

Art. V. Description of Mr. Cooper’s Lamp Furnace, for
the Analysis of Organic Bodies.

Havrine had occasion to use Mr. Cooper’s lamp for the analysis of
organic bodies, described in the last volume of the Transactions of
the Society of Arts, and having found it very effectual, we have
taken the following account of it from that work, with an abstract
of the method of using it; and are enabled by Mr. Cooper’s
kindness to add the description of some improvements which he
has since made on the original apparatus.

Fig. 1. Plate iy. aa and 6 b, are two long spirit-lamps, each having
ten burners and wicks, the burners of each lamp sloping towards
those of the other, as seen in the end view, fig. 2. They are placed
in a tin tray c c, mountedon four feet. This tray is perforated in the
middle the whole length of the lamp, and as wide as ee, fig. 2.
The object in sloping the burners is, that they may clear the lamps
and approach each other as near as is requisite, yet leave free space
for a current of air, the tray being perforated and mounted on feet
for this purpose: dd are spring wires at each end.of the tray,
to receive the tube ff containing the substance to be analyzed, and
to hold it over the flames ; by pressing the shoulders g g, fig. 2,
the wires open to receive the tube, and close on removing the pres-
sure ; and should the tube be shorter than the lamps, an additional
support on a leaden foot, fig. 3, is placed through the opening e ¢
of the tray to rise between the flames, and hold the end of the
tube.

The tubes are coated with copper foil, wrapped spirally round
them ; if each succeeding fold be on half the other, there will be a
double coat of copper all the way, if on two-thirds, there will be
three layers of copper, by which the glass tube is prevented from
bending when hot, and becomes very uniformly heated. The spi-
rals are continued beyond the end of the tube to reach the support,
and leave the end within the flames. The dotted line at A, fig. 4,
shews the end of the tube short of the support, the foil is secured
at the last coil by binding wire, as at ¢.

for the Analysis of Organic Bodies. 233

Fig. 5, shews the foil in act of being wrapped on, also the pro-
portion of the space occupied by the materials; first the mixture
of oxide of copper with the material to be analyzed, next pure
oxide of copper, or copper filings, and lastly asbestos. When the
quantity of water formed is considerable, the tube is either
blown into a bulb, as at &, fig. 6, or melted on to one ready pre
pared.

Fig. 7, is a long funnel, made by drawing out the end otf a tube
of suitable thickness at m, till it is long and small enough through
n n to reach to the bottom of the tube, and then cutting it off at m,
by which liquids may be introduced to the bottom of the tube
without soiling the sides. .

. As the wicks nearest the trough are to be first lighted, and the
remainder in succession as the former finish their action, there are
upright supports of tin oo fixed on the lamps, one for each space
between the burners, against which to rest a slip of tin pp, to pre-
vent the lighted wicks from kindling those next, and it also enables
the experimenter to extinguish those which have done duty. In
fig. 2, the tin slip p p is shewn by dotted lines reaching from lamp
tolamp. Little flat caps are put on each burner when done with, to
prevent waste of spirit; fig. 8 shews one of these caps q in its
place. r7,fig. 1, is a shelf fixed to the mercurial trough, to hold the
lamps; ss, the graduated jar. The pipes, with corks, w w, fig. 2
are the apertures by which the spirit is poured into the lamps; their
places only are marked at w w, fig. 1, The whole of this appa-
raius is made of tin plate.

At first Mr. Cooper operated with a tube of one piece; and the
materials being put in when the tube was straight, it was afterward
heated and bent at the open extremity, so as to suit the mercurial
trough; but this has been improved upon by making the tube
shorter and having a bent piece, attached to it by a small flex-
ible tube of caoutchouc, f, fig. 1. It removes the chance of accident
from stiffness in the end of the tube, and the tubes being straight,
may be used many times in succession,

Mr, Cooper has also used with advantage, at times, the form of

234 Mr. Cooper’s Lamp Furnace,

receiver shewn at fig.9; it is about twelve inches long, and one inch
in diameter, and being filled with mercury and hung over a basin
is ready for use. When containing gas, its quantity is estimated
by the graduated scale on the tube, care being taken previously to
compensate for any difference of mercurial pressure by inserting the
long funnel and cork, fig. 10, into the mouth of the receiver, and
pouring mercury into the funnel until it is level with that in the re=
ceiver. It is easy afterwards to admit water or solution of potash
into the receiver to absorb the carbonic acid, and leave the nitrogen.
The oxide of copper required in using this instrument may be
procured either by burning the residuum of verdigris which has been
used in the preparation of acetic acid, or by heating plates of copper
with access of air, and quenching them in water. Great care
should be taken that the oxide be pure, and it should be pulverised
and heated ina crucible, stirring at the same time. It may then be
sifted, and the different portions preserved apart. The tube used
should be of crown or green-bottle glass, fourteen to fifteen inches
long, (not so long if the separate bent end piece is used,) and from
one to two tenths of an inch internal diameter; it should be clean and
dry, one end should be sealed up by a blow-pipe, and then it may be
balanced. The substance if volatile is now to be introduced, if
solid it may be shaken to the bottom, if fluid it is to be poured in
by the funnel, fig. 7. The quantity of substance is then to be
ascertained, and a portion of cold oxide of copper introduced, suf-
ficient to absorb the substance if fluid, and cover it about a quarter
of an inch; after which recently heated and still warm oxide is to
be added to the proper height. Then a portion of recently
ignited asbestos is introduced and pressed rather lightly on to the
oxide, and occupying from one to two inches. The tube, with its
contents, is then to be balanced again, after which itis to be enve=
loped in the copper foil, (care being taken that the foil does not
cover the part containing the asbestos,) and the end piece with its
caoutchouc tube is to be fastened on. :
The tube is then to be arranged as in the figure, and heat applied ;
the lamps are to haye but short wicks, so that the top of the flame

for the Analysis of Organic Bodies. 235

shall just touch the tube, and only one set will be required, unless the
tube be large, as for instance, half an inch in diameter * ; the lamps
are to be lighted in succession, those nearest the gazometer first.

If the substance to be analyzed be a vegetable salt, or be hy-
grometric, it must be dried, which is best done in vacuo, but which
Mr. Cooper effects also in the following manner. A wide-mouth
stoppered bottle is selected, and alsoa smaller bottle which will
easily go into it; a quantity of dry pulverized chloride of calcium is
then strewed over the bottom of the larger bottle, and the smaller,
containing the substance to be dried is also introduced; a small
piece of bibulous paper is moistened with alcohol and put inside the
larger phial; it is then lighted, and when it has burned for a second
or two, the stopper is put into the bottle, and the vacuum obtained
is such that the desiccation goes on very rapidly and effectually.

When substances of this kind are analyzed, they must, of course,
be-mixed with oxide of copper before they are introduced into the
tube ; a quantity of pure oxide is then to be put into the tube, and it
is as well to add afterwards a small quantity of copper filings
orshavings. In heating the tube the wicks are to be lighted as be-
fore, but instead of suffering the whole to burn at once, it is as well
to leave only three or four in action at a time, extinguishing the
others, but taking care to ignite the whole extent of tube at once at
the end of the process.

When nitrogen is present in the body to be analyzed it has a
tendency to become oxidized at high temperatures by the oxide of
copper, and in this case yields erroneous results. To obviate this
as much as possible Mr. Cooper has lately used protoxide of cop-
per, instead of peroxide ; and though he finds that in certain circum-
stances this also will impart oxygen to the nitrogen, yet it does so
with far greater difficulty than the peroxide: hence in all cases
where nitrogen is concerned, the protoxide should be used. The
protoxide is prepared by fusing peroxide of copper with copper
filings in excess; a mass of protoxide is obtained, which, on being
pulverized and sifted is fit for use,

* The power of the lamps is such that a thick platinum tube, half an inch
in diameter, may be rendered bright red-hot by them.

Art. VI, Description of a self-acting Blowpipe. By
Mr. H. B. Leeson.

Ir has, I believe, before been observed that bottles of Indian Rub-
ber might be expanded to a considerable size by condensing air
into them: Tam not, however, aware that bottles so filled with con-
densed air have been applied to the purposes of a Blowpipe.

The bottles I make use of vary in weight from half to three-
quarters of a pound, and may be readily procured at the Stationer’s.
To prepare them they should be boiled in water till completely
softened, which, if they are put into water already boiling, will
generally be accomplished in ten minutes or a quarter of an hour.
They must then be taken out and suffered to cool, when a brass
tube may be fitted into the neck of the bottle, having a small
cock screwed into it at one end, by which it may be connected with
the condensing syringe, and to which the blowpipe jets may be
attached. There should be a milled projection on the side of the
tube, for the purpose of more firmly attaching the bottle to it,
which may be effected by passing a ligature of waxed string round
the neck of the bottle on each side of the above-mentioned pro-
jection.

The bottle must next be filled with condensed air. After a few
strokes of the syringe a blister will be observed to form, which will
gradually enlarge till the greatest part of the bottle (which must be
selected uniform in substance, and free from defects,) has extended
to asimilar substance. The condensation should not then be con-
tinued farther.

Bottles of the size I have mentioned will generally extend from
fourteen to seventeen inches in diameter without bursting ; and
Thave occasionally extended them much beyond these dimen-
sions ; but in this the operator must, of course, be entirely directed
by his own observations.

The Indian rubber varies in its quality. There is one sort which
appears of a blacker hue before extension, but becomes very thin
and almost transparent on condensing air into it, whilst there is

Mr. Leeson on a Self-acting Blowpipe. 237

another sort haying a browner colour, which is much less yielding
in its substance, and cannot be extended to the same thinness as
the former.

I have found both sorts to answer my purpose, but the above
observations may be useful in determining the quantity of air which
may be condensed into the bottles with safety.

To apply these bottles when filled with condensed air, nothing
more is necessary than to remove the syringe, and in its place to-
screw on a jet of such bore as may be required. On opening the
cock the air will be expelled by the elasticity of the India Rubber,
and its own condensation, in a strong and uniform stream, which
in bottles of the size I have mentioned will continue from twenty=
five minutes to an hour, according to the size of the jet.

When once prepared the bottles may be constantly expanded to
the same dimensions without any danger of bursting. When the
air is exhausted, the bottles will be found somewhat enlarged in

_ dimensions, but may again be contracted by holding them before a

- fire, or a few minutes’ immersion in boiling water. This, however,

is unnecessary, since no subsequent inflation will be found to in-
crease the size of the bottle any further, and I have used the same
repeatedly without any apparent diminution of its elastic powers.
The principal advantages of this blowpipe are its great portability,
and length and steadiness of action, (in which I consider it much
superior to the hydraulic blowpipe,) together with the perfect liberty
at which, when properly mounted, it leaves the operator’s hands.
This blowpipe is applicable to any of the gases, and may, I cons
ceive, be applied with advantage to contain the explosive mixture of
oxygen and hydrogen, as no inconvenience can possibly accrue

from its bursting, beyond the loss of the bottle.

This blowpipe may be supplied with air or gas during an ex-
periment, by having a separate communication for the syringe into
the piece of tube before mentioned, and this will enable the ope-
rator to continue his experiments for any period of time.

Blowpipes on this construction may be procured, very neatly and
conveniently mounted, at Mr. Newman’s, No. 8, Lisle-Street,

. Leicester-Square.

Vo. XVII. Ss

Art. VII. ASTRONOMICAL'PHENOMENA arranged in Order of Suc-
cession, for the Months of July, August, and September in the Year 1824.
By James Soutnu, F.R.S.

(Continued from Page 84.)

JULY.
Planet’s or | = #| Sidereal * Planet’s or Planet’s or | = $ | Sidereal Planet’s or

é Star’s 23 Star’s P Star’s 32 Y Star’s

>| Name, &c, | &2) Time. Declination. S| Name, &e, | &”|) Time. Declination.

a =e a =°
H. M. D. M. H. M. D. M.

1) Seaiepece 641, 23 7N 8| 44 Oph...|5.6] 17 16 24 OS
Im. ¥....|7.8] 15 190r 8"39'mr. Moon.... 17.21 25.428
#s R.A. 11" 2’ Decl. 0° 26’ S. (cont.) XVII. 142] 8] 17 25 24 30S
Georgian . 19° 1 23 9S Georgian . 18 59 23 10S
Meréury.. 5 15 20 42N Mercury... 5 59 22 34N
Venus ... 612 23 35N Venus... 6 50 23 21N

2} Sun ..... 645 23 3N Bl Sun siege 714 22 22N
Moon.... 1148 5 78S Moon.... 18 17 24 478
Georgian . 19,.1;.23 98 24 Sagit..| 7] 18 23 24148
Mercury... 5 20 21 ON XVIUI.129} 6 | 18 28 23 39S
Venus... 617 23 34N 141} 6} 18 31 23 59S

3] Sun ..... 6 50 22 59N Georgian . 18 59 23 10S
Moon.... 1241 1057S Im. ¥....{7.8] 21 560r14"44’mrT.
Georgian . 19 1 23 9S ¥s R.A, 185 24’ Decl. 24° 21’ S. (12’N.)
Mercury.. 526 21 17N ELM. <5 sie 22 500r15°38(7’N.)
Venus... 6 23 23 32N Mercury. . 6 7 22 47N

4) Sun ...:, 6 54 22 53N Venus... 6 56 23 16N
Moon.... 13 35 16 6S 10} Sun .,... 718 22 14N
Georgian. 19° b 22 8S Im. * 1..] 8 | 15 49or 8°34'mT,
Mercury. . 5 81 21 35N ¥’s R.A. 19" 6! Decl. 22° 48’ S, (10’N.)
Venus... 628 23 31N Em, * 1.. 16 430r 9>28'mr.

5] Sun ..... 6 58 22 48N Im. * 2 ..] 6 | 17 520r10°37’mr.
Moon.... 14 30 20 20S ¥’s R.A. 19 10’ Decl. 22° 43'S. (5’N.)
Georgian . igo} 23 9S oSagit...|4.5] 18 54 22 OS
Mercury... 5 88 2151N = Sagit...|4.5] 18 59 2118S
Venus... 6 34 23 30N Georgian . 18 59 23 108

6} Sun ..... 7 2 22 42N Em. *2.. 19 5orl1'50'sr,(1’S.)
Moon.... 15 26 23 268 Moon,... 19 10 22 40S
42 Libre.|5.6} 15 30 23 148 Im. ¥ 3 ..| 8 | 19 41orl2"96’mr.
KY, 192,;| 6 | 15°42 23 27S *’s R.A. 19" 12’ Decl. 22° 24’ S. (cont.)
XV. 225..) 3] 15 50 22 6S Im. ¥ 4 ...|6.7| 22 Oorl4"44’mr.
Georgian - 19 0 2310S *’s R.A. 19" 16’ Decl. 22° 7’ 8. (14’N.)
Im. *....| 6 | 19 150r12" 15’. Em. * 4.. 22 330rl5® 177.14
*’s R.A. 15" 34’ Decl. 23° 50’ S. (3'S.) Im. *5...| 8 | 22 42o0r15"26mr.
Em olay 20 160r13"16™mr. ¥’s R.A. 192 17 Decl. 21° 58 S. (cont.)

ercury.. 5.45 22 6N Eclipse of ,
Venus ... 6 39. 23 29N eon t n988 4Gonls? $ifeey,

1) Sate on ate 7, 6 22:36 Moon sets eclipsed.
Moon.... 16 24 25 148 Mercury. . 614 22 59N
25Scorpii] 6| 16 36 25 12S Venus... 7 1 28 .10N
18 Oph...} 6 | 16 89 24 19S LU in, fa « 7 22 22 GN
26 —-...| 6] 1645 24 43S Im. ¥1..] 8 | 15 llor 7°52’mr.
Georgian . 19 0 2310S *’s R.A. 19" 56’ Decl. 19° 59’ S. (8/N.)
Mercury... 5 om 22 22 .N Em.* 1.. 16 160r 8'57’m7.(0')
Venus ... 645 23 27N Im.*2.. ue 16 590r 9"40/mr.

8) Sees. ao 710 22 29N *’s R.A. 192 59’ Decl. 19° 55'S. (1'N.)

42 Oph...|3.4) 17 11 24 49S Im.* 3. | 8 | 17 43o0r10°24’mr.

Astronomical Phenomena.

JULY.

Planet’s or
Star’s
Name, &c.

Sidereal

itude

of Stars.

Planet’s or
Star’s
Declination.

n

Time.

D
Ma;

‘Wg H. M. OD. M.
‘ll *’s R.A.20 0’ Decl. 19° 53'S. (4’S.)
Im. *4..| 8 | 17 440rl0%25'mr, ©
%’s R.A. 205 0’ Decl. 19° 34’ S. (12'N.)
Im. ¥5 ..] 8 | 17 450r1026’mr.
*’s R.A. 20" 0’ Decl. 19° 53’ S. (3'S.)

Em. *4.. 18 42o0r11423’m7r.(5’N)
Em. *3.. 18 45o0r11°26’m7r.(11’S)
Em. ¥5.. 18 47orl1h28’m7.(11'S)
Georgian . 18 59 23 11S
Moon.... 20 3 19 32S

XX. 80 ../7.8} 20 11 18 528

mw Capr...| 5 | 2017 18 47S
XX.154..1| 6 | 20 20 19 9S

Im. ¥ 6..| 8 | 21 22o0r]14" Q'mr.

%’s R.A. 20" 6’ Decl. 19° 38’ S..(5’S.)

Em. 6.. 22 130r14"53'mr.(13'S)
Mercury. . 6 22 23 5N
Venus... 7 6 23 4N
12) Sun ..... 727 21 58N
Georgian . 18 59 23 11S
XX. 341 ./7.8] 20 43 18 51S
Moon,... 20 52 15 36S
XKI.7.../7.8} 21 2 1511S
29 Capr..|5| 21 6 15 54S
Mercury. . 6 30 23 12N
Venus... 712 22 59N
3) Sun ,.... 731 21 50N
Georgian . 18 59 231158
17 Aquar.} 6} 2114 10 4S
XXI.134.|7.8} 2119 12 20S
£Aqu....|5| 2128 8 388
Moon.... 21.38 11.48
Mercury.. 6 38 23 18N
Venus... 7d? 22 538N
4) Sun ..... 735 21 41N
| | Georgian . 18 59 23 12S
| | Moon.... 2223 610S
Mercury. . 647 23 18N
| | Venus... 7 22.22 44N
15) Sun ..... 739 21 32N
| | Georgian. 18 58 23 12S
Mercury. . 6 57 23 17N
Venus... 728 22 34N
16) Sun ..... 744 21 22N
Georgian . 18 58 23 12S
Mercury. . 7. 6 2317N
Venus... 7 33 22 25N
17) Sun..... 747-21 12N
Georgian , 18 58 23 12S
Im. *#...+| 7 | 20 6o0rl223'mr.

#’s R.A. 3 44’ Decl. 22° 41’ N. (10' N.)|}24] Sun .....

Emo's. {| | 21 12 0r13"29’m7,(4’S.)

19

20

22

23

239
Planet’s or = 2 | Sidereal Planet’s or
Star’s ‘2s Star’s
Name, &c. | #2] Time, Declination.
= °

H. M. D. M.
Mercury, . 7-5 23 ON
Venus... 738 22 15N
Sun ,.... 7,51 21 “1N
Georgian . 18 58 23188
Mercury. . 724 23 1N
Venus... 744 22 6N
Sun fives who 20 Sl
Georgian . 18 58 23 13
Mercury. . 7 83 22 53N
Venus... 749 2156N
Sun ..... 759 20 39N
Georgian . 18 58 23138
Mercury. . 742 22 37N
Venus... 754 21 43N
Som gh 8 3 20 28N
Georgian . 18 57 23 148
Im. * 1..|7.8| 22 4o0rl4" 5’ur.

%’s R.A. 42 2 Decl. 23° 7’ N. (2’N.)
Em. *1.. 22 55o0rl4456'm7.(6'S.)
Im. ¥2..|.7 | 23 Oorl5® I’m.

x#’s R.A. 41 4’ Decl, 23° 8’ N. (5'S,)

Em. ¥2.. 23 450r15"46’m7.(11'S)
Mercury. . 7.51 22 21N
Venus... 769 21 29N

Sun tfsiey,- S$ 7 20 16N
Georgian . 18 57 23 148
Im.%...-| 6 | 20 550r12"52’mr,

#s RA. 40 57 Decl. 24° I’ N. (4’N.)

Em.s 21 Sorls® 2’mr.(2’N.)
Mercury. . 8 0 22 5N
Venus... 8 4 21 16N

Sun ,.... 811 20 4N
Georgian . 18 57 28 148

Im. ¥1..} 8 | 23 1%or15"10’mr,

#’s R.A, 6" 8’ Decl. 28° 40’ N. (11 N.)
Im. ¥ 2 ..|7.8| 23 240r15"17m7,
#’s R.A. 6 8’ Decl. 28° 40’ N. (1I'N.)
Im. ¥ 8 ...| 7 | 23 28o0r15"2I’mr,
%'s R.A. 6" 9’ Decl. 23° 32’ N. (3'N.)
Im. % 4...| 8 | 23 $30r15"26'mr.

#’s R.A. 6! 9’ Decl, 28° 20’ N. (9’8.)
Im. ¥ 5 ..| 8 | 23 450r15!38'N

*'s R.A, 6" 9’ Decl. 23° 32” N. (3’/N.)

Em. ¥1.. 23 5lorl5"44’mr.(11'N)
Em. ¥2., 23 580r}5"5)’m7r.(11'N)
Em, ¥*4. 0 l0orl6" 3’mr.(9'S)
Em. *3.. 0 130r16" 6mr.(3'N)
Em. * 5..« 0 8lorl62d’ur.(3'N)
Mercury. , 8 9 21 44N
Venus... 810 21 2N

815 19 52N
Venus .., 815 20 49N

240 Astronomical Phenomena.

JULY.
Planet’s or = 2] Sidereal Planet’s or Planet’s or Ze Sidereal Planet’s or

‘4 Star’s aes ‘ Star’s . Star’s 2s Star’s.

Bd Name, &c. ae Time. Declination. 2 Name, &e. aA! Time Declination.

a tote Ss ae

Hemel) De ET. H. .. D. oF.

24) Georgian . 18 57 23 14S 28] Mercury... 844 19 57N

25] Sun ..... 819 19 39N Georgian . 18 57 2315S
Mercury. . 819 21 22N 29} Sun ..... 8 34 18 448
Venus... 8 20 20 35N Venus 8 35 19 45N
Georgian . 18 57 23 158 Mercury. . 8 52 19 24N

26) Sun ..... 8 23 19 26N Georgian . 18 57 23 158
Venus... 825 20 18N 30) Sun ..... 8 38 18 30N
Mercury. . 8 27 20 54N Venus ... 8 41 19 28N
Georgian. 18 57 23 158 Mercury. . 9 0 18 5IN

Bi) Sun’ asso. 8 27 19 12N Georgian . 18 57 23 15S
Venus ... 8 30 20 2N ol] SUM crest 8 42 18 15N
Mercury. . 8 35 20 25N Venus 846 19 12N
Georgian . 18 57 23 158 Mercury. . 9 8 18 ITN

28] Sun ..... 8 31 18 58N Georgian . 18 57 23 158

AUGUST.
H. M. OD. M. H. M. D. M.

Sane a6 846 18 ON 6] Im. * 1.. 6 16 27o0r 726m.
Venus... 8 51 18 55N *’s R.A. 18" 51’ Decl. 23° 28'S. (11’N.)
Mercury. . 916 17 41N Em. *1.. 17 250r 824mr.(7'N.)
Moon.... 14:12 19 28 28 Sagit..] 6 | 18 36 22 34S

2) Sumi... 8 50 17 45N 30 6 | 18 40 22 21S
Venus... 8 56 18 35N 35 5 | 18 45 22 53S
Mercury. . 924 17 -3N Moon.. 18 54 23 268
Moon.... 15"9 22) S2S Im, of Georgian 19 4orl0" 3’mr.

3] ‘Sun ..... 854 17 29N Im. *¥2..| *s |] 19 540r10"53’mr.
Venus... 9 1 18 14N #’s R.A. 18" 55’ Decl. 23° 6 S. (cont.)
Mercury. . 9 32 16 25N Em. Georgian 20 16o0rl1"15’mr,
Moon.... 16 6 2450S 7 Sans fee 9 9 16 24N
Im.%....| 4 | 18 32or 9°43’mT. Venus... 920 1652N
*’s R.A. 16" 10’ Decl. 25° 10’ S. (14’S.) Mercury. . 10 1 13 49N
Bio leis. e 5orl0"15’ (13'S.) XIX. 176.) 7] 19 26 19 14S

ALT oi ctay'e 8 58 17 13N 56 Sagit..] 6 | 19 36 20 10S
Venus... 9 6 #17 54N 57 .-(5.6] 19 42 19 29S
Mercury. . 940 15 46N Moon.... 19 46 20 39S
Moon.... LAS aSSt Sues Im. *. 22 6orl3! O'mr.

@ Oph....|3.4) 17 11 24 49S x's R A. oh 50’ Decl. 20° 20’ S. (14’N)
44—....|5.6] 17 16 24 0S Ems. #023 23 Torl4” 0'mr.(0’)
XVII. 142 17 25. 24 30S 8} Sun ..... 913 16.7N

SL WSTTI ais, sie 9 2 16 57N Venus . 925 16 29N
Venus... 910 17. 33N Mercury. . 10 8 13 ON
Mercury... 947. 15-5N 13 Capr.. 20 27 15 458
63 Oph...|6.7] 17 44 2451S XX. 240.. 20 31 1645S
5 Sagit...) 7} 17 49 24-16S Moon.. 20 35 17 0S
XVIL 342) 7/1754 24 248 : XX. 367.. 20 45 15 57S
Moon.... 1759 25° 9S 9} Sun ..... 917 15 50N

6] Sun ..... 9 5. 16 4YN Venus . 930 16 6N
Venus... 9 15 W7asN Mercury.. 10 15 12 18N
Mercury. . 954 14 24N Im. x. 19 Sor 955’.

Astronomical Phenomena.

AUGUST.

Planet's or z =| Sidereal Planet’s or
Star’s aS Star’s
Name, Ke. a2 Time. Declination.
= °
H. M. D. M.

*’s R.A, 21" 20’ Decl. 12° 50’ S.(14’N.)
ime .. : 20 lorl0"47’m7.(6’N.)
XXI.82../7.8] 21 12 1212S
XXI. 134./7.8] 21 19 12 19S
Moon.... 2123 12 41S
a Capric. ./5.6} 21 37 12 10S
Sun ..... 9°21" 15 °32N
Venus . 935 15 43N
Mercury... 10.21 ° 11 385N
30 Aquar.|5.6] 21 54 7 22S
XXI.403.| 8 | 2159 7148S
XXII 14.} 8 | 22 3 7208S
Moon.... 22 8 7558

Tm. *1../8.9} 0 490r15"31’mr.
*'s R.A. 22) 12’ Decl. 7° 8’ S. (13’N.)
Im.*2..| 7 | 0 500r15"32’mr.
*’s R.A. 22h 19’ Decl. 7° 8’ S. (12’N.)
Im. ¥ 3 ..|8.9| 1 lorl5"43’mr.
*’s R A. 22" 13’ Decl. 7° 4’ S. (12'N.)

Em. *1.. 1 540r16"36'mr.(0’)
Em. * 2 1 56or16438’Mr.(2’S.)
Em. * 3 2 1lorl6"53’mT.(2’S.)
Sun ..... 924 ».15 15N
Venus . 940 15 20N
Mercury. . 10 27 10 52N

Im. *..../8.9] 20 370rl1"16’Mr.
%’s R.A. 225 51’ Decl. 3° 23’ S. (6'S.)

Em... 21 23or12" 2'wr.(15'S.)
Moon.... 22 53 492 528
XXIIL68./6.7} 2315 0 40S

12 Pise....|.7 | 23 20 2.08

14 —...|6.7| 23 25 2138

SUR <.15'-%. - 928 14 57N

Venus ..- 945 14 57N
Mercury. . 10 34 10 8N -

Im. *1..| 6 | 16 300r 7" 6MrT.

%’s R.A. 235 27’ Decl. 1° 8’ N. (4'N.)

Em. *1.. 17 27or 8" omur(7S.)
y Piscium |4.5| 23 8 2 20N

=f 6.) 28.11 4 25N

17 -/4.5| 23 $1 4 41N
Daiit, % Ze. 23 360r14"10’mr,

#’s R.A, 23 87’ Decl. 2° 31! N. (13'S.)
Moon.... S37s8n) 2ATN

Em. * 2 0 40 0r15"14’mr.(1'S.)
Sun as 932 14 38N
Venus... 950 14 84N
Mercury... 10 40 9 25N
Im.%....| 6 | 20 Sorl0"39'mr.

%'s R.A. 0" 17 Decl. 6° 43’ N.

(S'N.)
Em. *..

20 58orl1"24’mr(3'N.)

Moon.. 022 722N

Days.

14

15

1

~o

7

0

2)

22

241
Planet’s or 3 2) Sidereal Planet’s or
Star’s 28 Star’s
Name, &c. a) Time Declination.
ss
H. M. D.°M.

Suny wee 9 36 14 20N
Venus 955 14 °9N
Mercury. . 1046 8 42N

Im. *%....|7.8] 0 360r15" 2’mrT.
*’s B.A. 129’ Decl. 12° 42’ N. (5°N.)

Em... 1 540r16"20’mT.(9'S.)
SUM rs as 940 14 1N
Venus... 1D D* 134SN
Mercury. . 10 51 758N
SuWijen,s es 943 13 42N
Venus... 10 5 13 18N
Mercury. - LOPS EFT AN

Im. *2..] 7 | 22 280rl2847 mr.

*’s R.A. 20 45! Decl. 19° 39’ N. (8’N.)
Im.* 1..| 7 | 22 500r13" 9'urT,

¥’s R.A. 2 44 Decl. 19° 51’ N. (cont.)
Em. ¥2.. 23 290r13447'(2S.)
Im.*3..| 6 | O 17orl4>35’mr.

x’s R.A. 2" 48! Decl. 19° 57’ N. (9S.)

Em. * 3 1 2lorl5" 39’mr.(2’S)
Sante 947 13 23N

Venus .. 10 9 12 53N
Mercury. . 11 3 6 31N
Im.x....{7.8] 0 lorl4"l@mrT.

x’s R.A. 3! 42’ Decl. 22° 9’ N. (cont.)
Im. ¥2..| 7] 1 Q9orl5"23'mr-.

xs R.A. 3" 44’ Decl. 22° 41’ N. (6'N.)
Em. *2.. 2 150r16"29'mT.(1'S.)
Im. *¥3. ‘lei 2 250r16"39'mr.

#3 R.A. 32 47 Decl. 22° 39’ N. (4’S.)

Em. *3.. 3 29o0r17843/(105S.)
SUED Sore te - 951 13 4
Venus 10 14.12 27N
Mercury. UB b SE mar wat at

Im. * 1 ..|7.8] 20 360r10"48’mr.

xs R.A. 4 31’ Decl. 23° 41’ N. (9'N.)
Im.*2..| 7 | 21 4orl1"15'mr.

#’s R.A. 4" 33’ Decl. 23° 45’ N. (10/N.)

Em, * 1 21 16o0rl127'mr.(5'N.)
Em. *%2.. 21 44orl1"55(5'N.)
SUB bc wes 9 54 12 44N
Venus 1019 12 2N
Mercury. . 11/15. y 5S 4N
Suni. saa 9 58 12 25N
Venus... 10 24 11 34N
Mercury. . 1120 4 22N
Sun). 2% 10 2 12. 5N
Venus... 10 28 11 6N
Mercury. . 1126 3 40N
Sint suas) 10 6 11 44N
Venus... 10 338 10 89N
Mexeury. . 11 31 2 57N

Astronomical Phenomena.

AUGUST.

v 9
wc ot ae
Planet’s or | 5 Z| Sidereal Planets or Planet’s or | = £| Sidereal Planet’s or
Star’s aa . Star’s P. Star’s = 5 Star’s
e Name, &c. og? Time. Declination. 2] Name, &e. wae Time Declination.
3 = we
=) = Q Pi

Sunss... 10 9 11 24N 28 - a Laoag J
Venus.... 10 38 10 1IN Mercury. . lee D Lae es
Mercury,.. 1] 36, ..2 15N 29| Sun ....-- 10 31 9 19N
24) Sun ..is. 10, 13, ,11) AN Venus... 11) 6 Ren
Venus.... 10 42 9 44N Mercury 12 4 1458
Merecury.. 1140 1 33N Moon.... 14 48 21 128
25) Sun ..... 10 17 10 43N 30} Sun ..... 10 35 8 57N
Venus... 10.47 9 17N Venus... li 9 ‘6 ba
Mercury... 1145 0 52N Mercuty.. 12 9 2235
26} Sun ..... 10 20 10 22N Moon.... 15 46 23 588
Venus. « 1051 8 48N Im. *....| 7 | 19 200r 8'44’mrT.
Mercury... 1150. 0 12N x’s R.A. 15" 52’ Decl. 24° 31'S. (cont.)
27) Sun sy... 10 24 10 1N 31) Suns .c. 1039 8 35N
Venus.... 1056 8 19N Venus.... 11 14 624N
Mercury.. 1155 0 2758 Mercury. . 12218, 8 15
28] Sun is... 10 28 9 40N Moon.... 16 45 25 198

SEPTEMBER.

~ XK. D. M. H. M. D. M.

J) Sun... 10 42. 8 14N 4] x’s R.A. 204 19’ Decl, 18° 27’ S. (r's,)
Venus ... 11,19. 5 55N Im. ¥ 3 ..|6.7] 19 500r 8"55’mrT.
Mercury. . 12 16 3 38S x’s R.A. 208 19’ Decl. 18" 1’ S. (15’N.)
Moon.... 17,41, 25 J6S Em. * 2. 20 Gor 9"10’m?.(15'S.)

f B) Sun. sana. 1046 7 52N XX.45..|8|20 6 1649S
Venus ... 11238. 525N Em. *1.. 20 130r 9h 17’mr(12'S,)
Mercury. . 1220 4138S Em, ¥2.. 20 l5or 9"19’'mT.(10°N)F
Moon.... 18 36 23 58S Moon.... 20 20 18118
v1Sagit..| 5 | 18 44 22578 XX.194..| 7 | 20 26 17 78
XVIII.255/6.7] 18 51 22 568 XX. 240../6.7] 20 31 16458

2946.7] 18 56 22 458 5) San. g.s > 10 57 645N |

3} Sun ..... 1049 7 30N Venus ... 11 37 8 54N |
Venus... 1128 455N Mercury... 12 82 5 558 }
Mercury... 1224 4188S Im. ¥ 1 ..] 7 | 20 40or 941’mr.
Im. ¥ 1 ..|7.8] 19 llor 8"19’mr. x's R.A. 21" 8 Decl. 14° 0'S. (9'N.)
#’s R.A. 190 20° Decl. 21° 42’ S. (7’8.) Im.%2..] [20 42or 9h43'ur. Of
Im. ¥2..] 8 | 19 160r 8h24’mr, %’s R.A. 21" 6 Decl. 13° 55’ S (cont.) |
#3 R.A. 198 30! yes 21° 39’ S. (4S.) 8 Aquar..| 6 | 20 50 13 448 ‘|

| Moon.. 929 2130S y= aa 21, 0°) Teas
56 Sagit. . 6 19 36 20 10S Moon.... vi Yi oe
57 -.15.6] 19 42 19 295 18 Aguar. 2115 13 388
XIX. 377.] 8 | 19 55 2148S Em. ¥1.. 21 580rl0"59'mT.(4'S.) 7
Em. * 1.. 20 Sor 9"11/mr.(1398.) Im. ¥ 3 ..] 7 | 22 42o0r]1"42’mr.

Em. * 2.. 20 180r 9h26’m7.(12'S.) ¥’s R.A. 21 10! Decl. 18° 43'S. (4N

4) Sun ..... 1053 7 SN Em. * 3.. 23 550r12455 mr.(9'S,)
Venus... 1132 425N 6) Sun ..... 11 0 6 23N
Mercury. . 12 28 5 23S Venus ... 1141 3 24N ;
Im.%1..{| 5] 19 2or 8 7wr. Mercury. . 12 35 6 268.

x's R.A. 20! 19" Decl. 18° 23’ S, (3'S.) Im.*1..|7.8 17 350r 6532'ur. |

Im.*¥2. nm ql 19 130r 8) 18'mr, x's TL.A. 21" 48! Decl. 10° 24'S. (“8

Astronomical Phenomena, 243,

SEPTEMBER.

Planet’s or 3 Z| Sidereal Planet’s ot Planet’s or | = 2] Sidereal Planct’s or
Star’s zs 4 Star’s_ . Star’s 2 Eh wa Star’s
oc | Time. Declination. é Name, &c. i?) Time. Declination.
=e a =?
H. M. oD. M. H. M. D. M.
6] Em. * 1. 18 14or 7/11’w7r.(14’S,)}}12} Sun ..... 1122 4 TN
& Aquar.. -| 542128 8 388 Venus ... 12 9 020N
46 Capr..| 6 | 21 36 9 53S Mercury. . 1253 9 7S
Tm. * 2 ..|7.8] 21 38o0rl0434’mr. Im. *....|6.7] 20 17or 8"50'm7.
#s R.A. 21 54’ Decl. 9° 21'S. (19/N.) ¥’s R.A. 2) 24’ Decl. 18° 6’ N. (15’N.)
Moon.... 2153 9 30S Em. i. 20 550r 9528'mr.(8’N.)
XXII. 44./4.5] 22 8 8 39S 13) Sun ..... 1125 3 44N
Em. * 2.. 22 LL eae We Venus ... 1214 0118
{7 Sun..... iB! 6 1N Mercury. . 1255 9 308
Venus... 11 46 2 54N Im. 1 Sat.. 2 3lorl4"59'mT.(1004+
Mercury. . 12 39 6588S Im.%....|6.7 3 56 or15"24’/m Tr.
60 Aquar.|6.7| 22 25 2 28S *’s R.A. “gh 28’ Decl. 22° 5’ N. (15'N.)
XXII. 183]7.8] 22 32. 4 28S Em,....3 3 320r16" 0’'mT.(12’N
Moon.... 22 39 «644 348 14) Sun’..... 11 29 3-21N
XXIII. 17]7.8) 23 5 3358 Venus ... 1218 0428
8] Sun ..... ll 7 5 38N Mercury. . 1257 9 478
Venus ... 1151 2-23N Im.%....] 7 | O llorl?)35’Mr.
Mercury. « 12 42 7268 x's R.A. 4 20" Decl. 23° 11’ N. (9/S.)
Im. * 1 ..] 6 | 19 390r 8827’mr. Em...... 0 540r13"18'mT ie
%’s R.A. 235 18’ Decl. 0° 10’N. (5’N.) |/15] Sun ..... 11 33 2 58N
Em. * 1.. 20 32or 920'mr.(3’N.) Venus... 1223 1428
XXIMN.15] 8] 23 5 1 15N Mercury. . 12 59 10 458
y Piscium |4.5} 23 8 2 20N Im.%1..] 6] 3 llorl5®31’/mT.
% 5.6) 23 18 0 18N ¥s R.A. 5 25! Decl. 23° 55! N. (5'S.)
Moon.... 23 23 «©6—0 33N Im.*%2..] 8] 3 240rl5"44MT.
Im. *%2..] 9 0 41or13*28/mT. *’s R.A. 5!" 24’ Decl. 24° 10’ N. (10’S.)
%’s R.A, 23" 25’ Decl. 1° 2° N. (5’N.) Em. * 1. 4 120r16"32’mT.(6'S.)
Em. * 2. | 1 550r14"42/m7,(1 1S.) Em. ¥2.. 4 16o0r16"36'mT. WS.)
Im.% 3 ..| 6 | 2 280r15"10’mr. 16] Sun ..... 1136 2 35N
*’s R.A. 23" 27' Decl. 1° 8’ N. (11'S.) Venus ... 12 27 #1438
Em. * 3.. 2 32or15"19'mr. (13'S.) Mercury. . 138 0 10215
9} Sun ..... a 1) *6 15'N 17} Sun ..... 1140 2 11N
Venus... 1] 55 (1 52.N Venus ... 12 31 2148
Mercury. . 1245 7548 Mercury. . 13 1 10308
26 Pisc...| 6 | 23 46 6 6N Im.*....|7.8] 0 120r1224’/mr.
wo —=—,..|4.5| 23 50 5 44N #’s RA. ‘qh 17’ Decl. 20° 36’ N. (5'S.)
Moon.... 0 8 5 52N Bim fe). 1 2orl3"14’mr.(2'S.)
45 Pisc...| 6 017 =%643N 18] Sun ..... 1143 148N
10} Sun ... 1115 4 53N Venus ... 12 36 2448
Venus... ID. Og SIM Mercury 13 1 10 38S
Mercury. . 1248 82258 19} Sun ..... 1147 125N
O 149...\7.8} 0 32 12 ON Venus... 1240 3158
58Pisc...|6| 038 11 IN Mercury. . 13 2 10478
O 247...| 8 049 1111N 20) Sun ..... 11 51 1 1N
Moon.... 055 10 34N Venus... 1245 $3458
1}] Sun ..... 1118 4 30N Mercury. . 13 2 1047S
Venus ... 12 5 0 50N Im. 1 Sat.. 4 530r16"53'm7.(100+)
Mercury. . 1250 8 45N 21) Sun ..... 1154 0 38N
Im.%*....6.7| 17 390r 6"16'mr, Venus... 1249 4168S
%’s R.A. 1 30’ Decl. 18° 23’ N. (4’S.) Mercury. . 13 2 1046S
Em...... 18 29or 7 6/wr,(16'S,))/22; Sun ..... 1158 0 15N
Moon.... 144 15 8N | Venus. 1254 44658

244

2
A

26

27

28)

29

Astronomical Phenomena.

SEPTEMBER.
Planet’s or 3 =| Sidereal Planet’s or Planet’s or 3 é | Sidereal Planet’s or
Star’s <2 Star’s E Star’s 28 Star’s
Name, &e. | &”! Time. Declination. 3] Name, &e. | ¥”| Time. Declination.
=¢ a Ss
H. M. D. M, | H. M. D. M.

Mercury... 13 2 10 45S Im. ¥ 4..] 8 | 21-360r 9" 2’.

Sun tei <jep igri 6 9S x's R.A. 184 23’ Decl. 24° 15’ S. (9’S.)
Venus... 12°59 5 17S Im. * 5 ..|6.7| 21 540r 9"19’mr.
Mercury. . 13, 0r-10 33S %’s R.A. 18" 24’ Decl. 24° 9’ S.( 5S.)
Sunita... 12-5 0325S Em. *2.. 22 4or 9529'mT.(11’N
Mercury. . 1259 1020S Em. * 4 22 17or 9442’mr.(14’S.
Venus .. 13:3 6547S Em. * 3 22 3lor 9456’mT.( 10'S.)
Suny 2. 12 9 0056S Em. * 5 22 460r1011’m7,(11’S.)
Mercury. . 1257 10 7S 30| Sun...... 1227, 2,538
Venus... 13 8 6188S Mercury. . 1242 7378S

SUB ke sh 12° 12¢.07°19'S Venus... 13 30 8458S
Mercury... 1254 9418S Im. * 1 ..|7.8| 18 42or 6" 4’mr.
Venus... 13 12 6478S ¥’s R.A. 19" 10’ Decl. 22° 7’ S. (15’N.)
Sun)...., 1216 14388 Im.*2..| 7] 19. 2or 6424’mr.
Mercury. . 12:51 “9 15S ’s R.A. 19" 12’ Decl. 22° 24’ S. (5’S.)
Venus... 1317 T10S Em. * 1.. 19 Sor 6'25’mr.(13’N)
Moon 16 20 24 418 Moon.... 19:11 2218S

Sun ..05 Je 12,19, 2 6S 50 Sagit../6.7} 19 16 22 78S
Mercury. . 1248 8498S XIX.138.} 6 | 19 20 2140S
Venus... 1321 7468S — 166.| 7] 19 25 21 9S
Moon.. 17:19 25 12S Em. * 2..| 7 | 20 4or 726’m7.(12’S.)
Sun..... 12,23 229.8 Im.* 3 ..] 5 | 20 l4or 736™rT.
Mercury. . 1245 8138S *’s R.A. 19" 13’ Decl. 22° 5’ S.(6’N.)
Venus ... 13 26 8168S Em. * 3.. 21 27or 8'49'mr.(4’S.)
Moon.... 18 17 24 208 Im. * 4..| 8 | 21 340r 856r.
Im. ¥ 1 ..} 9 | 19 330r 6"59’MT. *’s R.A. 19" 16’ Decl. 21° 53’ S.(7’/N.)

xs R.A. 18" 20’ Decl. 24° 10’.S. (8’N.)
Em. * 1.. 20 40or 8" 6’mr.(2’N.)
Im. *2..] 7 | 21 1l0or 8°36'mr.

x's R.A, 18" 22’ Decl. 24° 14’ S. (5’S.)
Im..* 3 ...|6.7] 21 32or 8'58’mr.

*’s R.A. 18" 23’ Decl. 24° 9’ S, (3’S.)

Im. * 5 ..|6.7| 21 49o0r 9°11’.

*’s R.A. 19" 16’ Decl. 22° 7’ S. (9’S.)
Pere eee| | 22 27or 9549’mT.(14'S.)
Im.* 6 ..| 8 | 22 340r 9556'mrT.

xs R.A. 19" 16’ Decl. 21° 35’ S. (cont.)
Embtetcs | 22 440rl0" 6’m7.(2’S.)

245

- Art. VIII. On the Soundings in the British Channel.

[To the Editor of the Quarterly Journal.

Sir,—A paper has been lately read at the Royal Irish Academy
by Mr. A. Nimmo, civil engineer, containing the ingenious idea
that the various coloured sands, shells, and ooze found at the bot-
tom of the sea, in the chaps of the Channel, are the terminations
of beds of granite, limestone, coal, §c., which dip from various
parts of Great Britain and Ireland, and to which they may be sa-
tisfactorily traced.

This idea, if properly pursued, would materially assist in classi-
fying the soundings in our Channel charts. It is needless to insist
upon the great importance of a correct projection of those sound-
ings ; in conjunction with the depth of the water, they are frequently
the only means that the seaman possesses, in thick weather and
long nights, of ascertaining his position ; and it is too well known
that the most part of the soundings in both the channels, and the
whole of them on the great western bank, are laid down on our
present charts in a manner that is altogether disgraceful to the
age. No uniform means have ever been taken to amend them;
they are miserable compilations, or copies of each other, and the
few correct soundings that have been here and there interpolated,
instead of serving as standard points to adjust the rest, actually
increase the general confusion,

The Admiralty has for some time very judiciously employed Mr.
Tiarcks in determining the longitudes of several interesting places,
by the mean of a multitude of chronometers. Would not a similar
method, devoted, for a few summers, to the construction of an en-
tirely new chart of these banks, be one of the most essential benefits
that could be conferred on the navigation and commerce of our
home seas ?

A frigate or other convenient ship might carry the necessary
instruments and chronometers, while the soundings should be
taken by tenders, or in fine weather, and particularly in strong
tides, by boats. The ship should go sufliciently off the wind to avoid

246 On the Soundings in the British Channel.

leeway as muchas possible, her track should be slow but undevi-
ating, and her constant observations for latitude and longitude
should be connected by the perpetual log of Gough or Massey.
The sounding vessels should move in parallel lines to the course
of the centre ship, there might be three or four of them on each
quarter, and their precise situation when the lead was at the bot-
tom, and the line perpendicular, would be ascertained by their
bearing, and the angular altitude of her mast-head.

The depth of the water, uniformly reduced either to the mean or
the minimum of spring-tides, and the nature of the bottom, would
be the two principal points of inquiry ; but an excellent opportunity
would be likewise afforded for learning the direction, duration, and
combination of the tides in the offing, their real rise and fall at a
distance from the land, and the influence of the Atlantic and Bis-
cayan currents on the tides, as well as their united effect in trans-
porting the various deposits from the rivers, by means of which a
constant accumulation of sand or mud is produced in one place,
while the rocky bottom is denuded in another. How far the tem-
perature of the sea is affected by proximity to the land, or by the
shoaling of the water, and to what cause is to be ascribed the
mutable colour of the sea, which suddenly varies from light green
to dark blue, are two amongst several other subjects of research
which would well deserve the attention of the person employed on
this service.

To preserve consistency in the terms used to describe the
several substances found at the bottom, and which are now
named with the most amusing caprice, such as crab’s eyes, oat-
husks, hake’s teeth, §c., every cast ‘of the lead should be regis-
tered, and the arming cut off and numbered in like manner ; or
the sand might be separated from the tallow, washed, and folded
up in papers. These, with all the other data, should be trans-
mitted to the Hydrographical Office, where they might be laid
out in their respective situations on the floor of a large room,
graduated for that purpose, and where they would be easily
grouped, so as to shew the general arrangement of the districts
of the sands, gravel, shells, and stones.

On the Soundings in the British Channel. 247

The geologist would likewise find in this model (if it may be so
called) of the mouth of the channel a most interesting subject for
investigation ;—he would trace the connexion between these sub-
stances and the several strata of the adjacent shores; he would
determine whether the shells and other organic fragments are
recent or fossile ; and he would distinguish the predominant from
the adventitious matter which currents and other accidental causes
have strewed in some places to the frequent perplexity of seamen.

If these suggestions should be adopted by the present en-
lightened and active Board of Admiralty, it may be presumed
that they would produce information of considerable value both
to the philosopher and the sailor; but it is certain that they would
lead to the formation of an accurate and rational submarine
map of the channel, and thereby accomplish one of the most im-
portant desiderata of practical navigation. Iam, Sir,

Your’s, &e. B.

Art. IX. Some particulars respecting the Ornithorhynchus
Paradoxus. By H. Scott, Esq.

I spent a week at Bathurst, in October 1820, (the commencement

of the Australian spring,) and during my stay there I received

from a young man, born in the colony, the following note, and

also the female ornithorhynchus, to which it alludes :

Sir, Oct. 13.
The bearer, (a native black man,) is one of the men that

came with me,

I yesterday evening went to shoot some ducks, and was fortu-
nate enough to take a female platypus from ler nest, of which I
shall give an account when I see you, and was lucky enough to
catch a pair of young swans, which I now send.

I am, Sir, your most obedient,
Joun Row ey.

I received the above about twelve o’clock the same day, Mr.
Rowley being then at a lagoon about nine miles distant,

248 Mr. Scott on the Ornithorhynchus Paradorus.

The animal was very lively, and I put it into a large tub of
water, and fastened a string to its hind leg, that it might not
escape in the night; this caused an inflammation, and the next
morning it died.

I watched its motions during the whole of the of Seorier and
questioned the native black, (through the medium of another who
spoke English remarkably well,) as to its haunts and habits, and
the following are my observations and his account.

It was extremely lively, and would attempt to bite when touched,
but did not hurt.

The beak is soft and slimy ; it dives down and rises again im-
mediately, shaking its head and bill like a duck ; it runs, or rather
crawls, one foot before the other on the ground, somewhat fast;
its excrement is soft and brown like that of a bird; it scratches its
head and neck with its hind foot like a dog; its eye is very round,
but the socket is oblong; the colour of the irisa dark brown, the
pupil very minute and blue, rather a prussian blue; it breathes
through one nostril, apparently, as if the water came from one
only. In the evening it became rather more lively, but died the
following morning, when Mr. Hill, a surgeon of the Royal Navy,
who was with us, opened and dissected it, and wrote me a letter,
which I have added to this account.

From Cook-a-Gong, chief of the Burrah-Burrah tribe, our
guide, I learnt that this animal had just finished building her nest,
which has a long niche or tube to creep into, and which leads to a
round hollow, the whole lined with reeds and moss.

It is built amongst reeds in still water*; it lays two eggs at a
time, their colour white, and their size that of a small sized hen’s

* A few days afterwards I passed through this lagoon, and rode up to the
nest, the waters being above my horse’s knees. I founda large mass of reeds
scratched and twisted together on the stump or root of one of the reeds ; the
canal had been nearly destroyed in getting the animal out, but the large
hollow lined with moss was perfect, and appeared moist. She sat with her
bill about an inch or two above the water for air; this in several other places,
during a six weeks’ tour in the interior, I found to be inyariably the case in
rivers, and the most usual mode of discovering them, which, in general, was
difficult, for they are very quick-sighted and hy,

Mr. Scott on the Ornithorhynchus Paradorus. 249

egg; it sits on them a long time, and hatches them like a fowl; it
will not forsake its nest by being disturbed ; it eats soft mud, but
no grass or weed *,

They have been caught on dry ground some distance from the
river.

When attacked the male strikes with his hind leg, which has a
spur, (the female has none,) and the wound causes considerable
swelling and pain, but no instance of death in consequence has
been known. To cure the wound it is washed with cold water,
and sucked by the natives, who call it mullongone.

Mr. Hitz’s Lerrer.

Dear Sir, Sydney, January 14, 1821,

I have sent you the preparation of the female ornithorhynchus,
properly corked and sealed ; and from the state of preparation it is
nowin, Iam in hopes it will not require a change of spirits until
your arrival in England: it would be well, however, to examine it
occasionally on the voyage.

It consists of the internal organs of generation, the urinary
bladder, with part of the ureter attached, a small portion of the
rectum, and the whole of the external parts.

You will observe that the preparation shews:

1. One common external orifice for the rectum, vagina, and
urinary bladder,

2. That the vagina, termination of the rectum, §c., remain un=
examined.

3. The urinary bladder.

4. The junction of the fallopian tubes in one common canal,
(behind the bladder,) but without any organ or cavity, like the
uterus of viviparous animals: at their junction in this canal the
tubes are of thicker consistence, approaching a cartilaginous feel,

The urinary bladder, situated immediately before the common
canal, must not be mistaken for the uterus.

* Mr. Hill had caught and opened a male a few days before, and found
the stomach full of mud, and very offensive. The female I had was quite
empty, and not offensive,

250 Mr. Scott on the Ornithorhynchus Paradovus.

5. The fallopian tubes terminating in the ovaries.

6. The left ovary in an impregnated state, containing one
ovum of the size of a small pea, round, and of a yellow colour;
also two of smaller size, and a great number of minute vesicular
bodies hardly perceptible to the eye, but very evident with a mi-
croscope.

7. The right ovary without any signs of impregnation.

8. Part of the rectum, to shew its attachment and termination. .

The preparation of the spur* iI intend sending to Mr. M‘Leay,
as he was the first that published an account of it, and has always
supported the fact against a host of unbelievers. If you have
an opportunity of shewing him the other preparation, I am sure
he will feel much gratified.

Your most obedient servant,
Patrick Hiiz, Surgeon, R.N.
To — —

[We refer our readers to the third volume of Sir E, Home’s Lectures on Com-
parative Anatomy, (p. 341,) for further details and observations respect-
ing the anatomy and habits of this very singular animal.]

Art. X. Proceedings of the Royal Society.

Tue Society held their first Meeting after the Christmas Vacation,
on

Thursday, January 8,
when Anthony Story, Esq., was admitted a Fellow.

A paper was communicated by J, F. W. Herschel, and James
South, Esqrs., entitled, ‘‘ Observations on the apparent distances
and positions of, 380 double and triple stars, made in the years
1821, 1822, and 1823, and compared with those of other astrono-
mers ; together with an account of such changes as appear to have
taken place in them since their first discovery.”

* This is the spur from the male alluded to above.

+ During our excursion I frequently asked the natives, whom we met, what
were the effects of this spur‘? and they always made up piteous faces, and said,
“ murraybad,” (very bad.) These accidents haye happened also at Bathurst,

Proceedings of the Royal Society. 251

Thursday, January 15, -

Messrs. J. H. Vivian and M. Faraday were respectively ad-
mitted Fellows of the Society.

The reading cf Messrs. Herschel and South’s paper, of which the
following is an abstract, was resumed and concluded.

The determination of the apparent distances and positions of
such double stars as could be measured with micrometrical instru-
ments, and high magnifying powers, was suggested by Sir W.
Herschel more than forty years ago; and in his hands it led toa
new department of physical astronomy, by the discovery of sidereal
phenomena, referable to the agency of attractive forces. But the
determination of the existence of annual parallax, the immediate
object for which the inquiry was instituted, was soon lost sight of,
in the more extensive views of the construction of the Universe,
which gradually unfolded themselves. Nor has the investigation
been resumed, although from the precision with which such obser-
vations can be made, it seems in the opinion of the authors of this
paper likely to be the mode by which the existence or non-existence
of sensible parallax, will ultimately be determined.

The results of Sir William Herschel’s observations from 1779 to
1784, were published in the Philosophical Transactions for 1782
and 1785; and a re-examination after a lapse of twenty years was
undertaken by him in 1801-2-3 and 4; and in the Transactions
for 1802 and 1804, unexpected phenomena were communicated.
Instances in which two stars were performing to each other the
offices of sun and planet were proved to exist, and to more than one
pair the period of rotation was, according to the observations of
the authors of this paper, assigned with considerable exactness.
Immersions and emersions of stars behind each other had been
witnessed, and real motions among some of them had been ob-
served rapid enough to be detected, in very short intervals of
time.

But as from the novelty of the subject, and from the imperfec-
tions of the micrometers employed in 1779 and 1780, it was likely
hat some instances of error had occasionally crept in, it became

252 Proceedings of the Royal Society.

desirable that a second re-examination should be instituted: ac-
cordingly in the year 1816, some progress was made by Mr. —
Herschel towards its accomplishment, and the results are commu-
nicated in the present paper. A similar idea having, however, oc-
curred to Mr, South, it was at length determined that the obserya-
tions should be carried on in concert, and with his instruments.

Meanwhile (unknown to the authors of this paper) a similar
undertaking had been entered upon by a distinguished continental
astronomer, Mr. Struve, director of the Imperial Observatory at
Dorpat, and the general coincidence between the measures of this
observer and those of their own, is deemed at once interesting and
corroborative of the accuracy of both.

The instruments with which the observations accompanying this
paper were made, are a five and seven feet equatorial; the former
was constructed under the direction of the late Captain Huddart,
and is remarkable for its extreme lightness, for the promptitude
with which it obeys its adjustments, and for its ability in retaining
them. Its object glass 33 inches aperture, and of five feet focal
length, is the work of the late P. and J. Dollond, whilst its divided
circles, microscopes, &c., were completed by Messrs. I. and E.
Troughton. A description of it is given, and a drawing is annexed.
The latter is a telescope of seven feet focal length, and five inches
clear aperture; it was made by Tully, and is mounted on the polar
axis of the old equatorial sector, made for the royal observa-
tory, and for the use of which an acknowledgment is made to
the Council of the Society.

The micrometers employed are the work of Mr. Troughton, and
have long since been familiar to astronomers under the name of
Troughton’s Wire Micrometers. The measures of distance are all
central. The observations of each star were generally made in
each other’s presence ; but occasionally in different parts of the
observatory, and with different instruments, without any commu-
nication with each other; in some instances the observations of
Mr. Troughton or Mr. Richardson haye been appealed to, in order
to settle discrepancies. .

To the observations of each star the authors attach their mean

Proceedings of the Royal Society. 253

result: the results obtained by other observers are also placed in
the order in which they were made; but there is one circumstance
to which they solicit attention, namely, that as far as Sir William
Herschel’s observations are concerned, the dates and results will
not accord with those published by Sir William in the Trans-
actions, for reasons given in a former part of the paper.

As an Appendix, measures of a few stars less perfectly observed
are added, which, although not entitled to equal confidence with
the others, the authors think may, perhaps, still have their use.

Thursday, January 22.

Dr. Scudamore was admitted a Fellow of the Society.
The following paper was read : ;

On a Mode of preventing the Corrosion of Copper Sheeting by Sea
Water, in Ships of War, and other Ships. By Sir H. Davy,
Bart., P.R.S.

When copper sheeting, however pure the metal may be, is exposed
to sea water, a green rust is formed upon it, which, when washed
off, is replaced by a similar substance, till the whole of the metal
is thus destroyed by corrosion. To prevent this effect, the Presi-
dent avails himself of the modification of chemical affinities, derived
from electrical powers; and in pursuing his researches in relation
to this subject, he found the above-mentioned action upon copper
counteracted by very weak negative electricity easily excited in it by
the contact of a surface of tin, not exceeding ;4, that of the cop-
per, and made part of an electric circuit in sea-water. Other
metals may be substituted, but the ease with which a perfect
contact is made by solder with tin, and the facility with which its
submuriate detaches from the metal, induced Sir H. to regard it as
best adapted to the purpose. He observes further, that the cause
_ which prevents the oxidation of the copper, will also probably pre-
vent the adhesion of marine animals, and of vegetables. After
adverting to the unequivocal and satisfactory results of his experi-
ments made upon a small scale, the author states that the Lords
Vou, XVII. e

254 Proceedings of the Royal Society.

Commissioners of the Admiralty have enabled him to make arrange-
ments for pursuing them on a very extended plan.

A paper was also read entitled,

Experiments and Observations on the Developement of Magnetical
Properties in Steel and Iron, by Percussion. By W. Scoresby,
Jun., F.R.S.E. communicated by the President.

After adyerting to the general results of his former inquiries the
author observes, that his principal objects on the present occasion
were to endeavour by auxiliary rods of iron to increase the degree
of magnetism, and to ascertain on what circumstances as to the
magnitude of the iron rods, and the quality, size, and temper of the
steel wires, the utmost success of the method depends.

He formerly used a single iron rod, upon which the steel bars were
hammered, both being in a vertical position. He now places the steel
wire between two rods ofiron, and subjecting it through the medium
of the upper rod to percussion, derives the advantage of the mag-
netism of both rods of iron acting at the same time upon both its
poles. The rods he used were of the respective lengths of three and
one foot, and an inch diameter, and the upper end of the larger rod
and the lower one of the smaller rod were made conical, there being
an indentation in each to receive the ends of the steel wire. Some
magnetism was then elicited by percussion in the larger rod, and
the steel wire being properly placed between its upper extremity
and the lower one of the small rod, the upper end of the latter
was hammered, and magnetism thus communicated to the wire ;
whilst the lower rod receiving some influence from the percussion,
performed a similar office. The author calls this mode of pro-
ceeding the compound process, to distinguish it from the mere ham~
mering of the wire upon the rod, as practised by him formerly, and
which he terms the simple process. He then enters into extended
details of his several experiments, of which the following are the
principal results. 1. That the compound process is more effectual
in the production of magnetism than the simple one, though the
ratio of augmentation does not appear determinate. In one expe-
timent the maximum effect of the simple process was an attractive

Proceedings of the Royal Society. 205

foree capable of lifting between 186 and 246 grains, while the
compound process augmented the lifting power to 326 grains. In
another, the simple process gave a lifting power of 246, the com-
pound of 345 grains. Moreover, the efficacy of the compound
process is much less manifest upon long than short wires : ; and
the softer the wire the more susceptible it becomes of this magnetic
condition.

The author concludes this paper with some theoretical remarks
respecting the influence of percussion in disposing the particles
of iron to receive and retain magnetism, which he thinks {may
tend to explain some otherwise obscure phenomena, and which
seem to render it probable that the process of percussion may
be applied, in connexion with other modes of magnetising, for
giving increased power to magnets.

Thursday, January 29.

Thomas Amyot, Esq. was admitted a Fellow, and the following
paper was communicated.

Observations on the Iguana Tuberculata, the common Guana. By the
Rey. Lansdown Guilding, B.A., &c., communicated by Sir E.
Home, Bart., V.P.R.S.

The author’s chief object in this communication is to correct an
error into which many naturalists have fallen, of describing the
gular process of some lizards as a pouch eapable of inflation, and
to point out a new organ on the parietal bones of the head of the
Iguana, which he proposes to name Foramen Homeanum; it
leads to the cavity of the brain, and is covered by a brown
oval scale, semitransparent in the centre, but not affording
a passage to any nerve or blood vessel.

A paper was also read, entitled

A finite and exact Expression for the Refraction of an Almosphere,
nearly resembling that of the Earth. By Thomas Young, M.D.,
For. Sec. R.S.

Having shewn that if the pressure of the atmosphere be repre-
T2

256 Proceedings of the Royal Society.

sented either by the square or by the cube of the square root of
the density, the astronomical refraction may be obtained in a finite
equation ; and having adverted to Mr. Ivory’s computation of the
refraction with the assistance of converging series, and several trans-
formations from an equation which expresses the pressure in terms
of the density, and of its square, Dr. Young proceeds to observe,
that if we substitute for the simple density the cube of its square
root, we shall represent the constitution of the most important part
of the atmosphere with equal accuracy, although this expression
supposes the total height somewhat smaller than’ the truth; and
that we shall thus obtain a direct equation for the refraction which
agrees very nearly with Mr. Ivory’s table, and still more accurately
with that in the Nautical Almanac, and with the French tables.

At the horizon the refraction is equal to 33’ 49".5, which is only
1.5” less than the quantity assigned by the French tables and in
the Nautical Almanac, while Mr. Ivory makes it 34 17".5. Again,
for the altitude 5° 44’ 21” we obtain 8’ 49.5 for the refraction,
while the Nautical Almanac gives us 8’ 53”, and Mr. Ivory’s tables
8’ 49".6. The author, however, observes that there is no reason
for proceeding to compute a new table by this form u, since the
method employed for that in the Nautical Almanac is, in all com-
mon cases, more compendious; and even if it were desired to re-
present Mr. Ivory’s table by the approximation there employed, we
might obtain the same results with an error scarcely exceeding a
single second, from an equation of the same form.

Thursday, Feb. 5, and Thursday, Feb. 12.

At these Meetings
The Baxertan Lecturzr—On certain Motions produced in Fluid
Conductors, when transmitting the Electric Current. By J. F.
W. Herschel, Esq., F.R.S., was read.

In the first paragraphs of this lecture Mr. H. particularly de-
scribes the phenomena that result on placing a portion of mercury,
covered with sulphuric acid, between the voltaic poles immersed
on opposite sides of the globule of metal, but in contact with the

Proceedings of the Royal Society. 257

acid only. They consist in active motions of those particles of the
acid in contact with the mercury, while the superficial molecules
of the metal continually radiate from the point nearest the negative
pole, and darting to the positive pole, return along the axis. The
author particularly notices several singular appearances resulting
from this current, and shews them to be independent of any electro-
magnetic vortices, to which at first sight they present considerable
analogy; they are incomparably more forcible in proportion to the
electric powers used, than the motions produced by the action of
magnets. Hence they furnish an extremely sensible test of the
developement of feeble voltaic powers, not easily rendered sensible
by other means.

The author next describes the appearances observed in caseg
where other liquids and metals are used, and adverts to the influ-
ence of several causes upon the uniformity of the results. Among
these, impurity in the mercury is especially noticed, which should
not only be carefully distilled, but also well washed with dilute
nitric acid. Mercury thus purified, and placed in the circuit as
before, exhibits phenomena varying with the nature of the liquid.
Generally speaking, currents are produced radiating from the
point nearest the negative pole, which are most violent in acids?
-and less in saline solutions, in proportion as the electro-positive
energy of the base is greater. In many liquids a counter current
from the positive pole is observed ; but if either pole be brought into
‘contact with the mercury, no currents are observed from the point
of contact, but strong ones are perceived to radiate from the other,

If the negative pole touch, it amalgamates with the mercury,
which remains bright; if the positive pole, the mercury rapidly
oxidizes, and in both cases currents are produced.

Mr. H. proceeds to observe, that when mercury is electrized in
saline solutions, its properties are generally altered, and he de-
scribes at length the phenomena thus presented in a solution of
sulphate of soda, which were peculiar and apparently. perplexing,
but which he found to depend upon the presence of amalgam of
sodium, counteracting the effect of the negative pole, and exalting
that of the positive in propoytion to its quantity, until it overcomes

258 Proceedings of the Royal Society.

and even reverses it. That sodium is actually present in these
cases, the author shows by the following experiments :

Having detached the negative wire, he touched the mercury now
lying quiet in the liquid with a platinum or copper wire, and a
violent action instantly began. The mercury rushed to the wire
in a superficial current, and it gave off abundance of hydrogen,
The sodium, wire, and liquid, forming a voltaic combination suffi-
ciently powerful to decompose the water.

The author next proceeded to investigate more minutely the
effects of different metals in their contact and amaigamation with
mercury, employing solutions of the caustic alkalies for the con-
ducting liquids, which have the advantage of producing no cur-
rents in pure mercury, so long as neither pole is in contact with it.

In liquid potash a contact with the negative pole, of a single
second’s continuance, imparted to 100 grains of mercury the pro-
perty of rotating violently from the positive to the negative pole,
when the circuit was completed in the liquid alone. The rotation
was even forcible when the quantity of potassium did not probably
exceed a millionth part of the whole mass. With sodium similar
effects were observed, and even when the proportion of sodium to
mercury was only as 1: 1.600.000, a feeble motion was sensible.

The influence of barium, strontium, calcium, and. magnesium,
and of zinc, lead, tin, and iron, is next described, the alloys of
these metals being all possessed of the positive property. Copper,
on the other hand, does not communicate it, though present in
considerable proportion; nor do bismuth, silver, or gold.

Mr. Herschel concludes this lecture with some general and
theoretical observations and deductions, founded on his experi-
mental inquiries. These relate principally to the exceedingly mi-
nute proportions of extraneous matter, capable of communicating
sensible mechanical motions and properties of a definite character
to the body they are mixed with, When we see energies so in-
tense exerted by the ordinary forms of matter, we may, says the
author, reasonably ask, what evidence we have for the imponder-
ability of any of the powerful agents, to which so large a part of
the activity of material bodies seems to be owing?

Proceedings of the Royal Society. 259

Among the essential conditions of the phenomena, the author
particularly adverts to the vast difference of conducting power be~
tween the metallic bodies set in motion, and the liquid under
which they are immersed ; to the necessity of the perfect immisci-
bility of the conducting fluids, so as to render the transition from
one to the other quite sudden ; and to a certain chemical or elec-
trical relation between them. Under these conditions, Mr. H. ob-
serves, the phenomenon may admit of explanation, from what we
already know of the passage of electricity through conductors,
and the hich attractive and repulsive powers of the two electrici-
ties inter se. A body so highly electro-positive as potassium
present in mercury may, for instance, have its natural electrical
state exalted by its vicinity to the positive pole ; and being thus
repelled, may take the only course the resistance of the metal on
the one hand, and attraction of cohesion on the other, will permit,
viz., along the surface, to recede from the positive pole. It may
even act as a carrier to the positive electricity, which may adhere
to it too strongly to be transmitted through the mercury, and when
arrived at the opposite side of the globule may then, by the influ-
ence of the opposite pole, lose its exalted electrical state. Such an
explanation, however, is not without its difficulties, and although
another course is open to us, ‘that of considering the action which
takes place at the common surface of two unequally conducting
media, as dependent on a new power of the electric current, bear-
ing some analogy to magnetic action, yet this, in the present
state of the investigation, must be regarded not only as a bold,
but vague hypothesis.

Thursday, Feb. 19.

A Paper was read
On Semi=decussation of the Optic Nerves. By W.H. Wollaston,
M.D., V.P.R.S.
In the human brain, {the optic nerves, after passing forward to a
short distance from their origin in the thalami, become incorporated ,
and from the point of union two nerves are sent off, one to each
eye. To this united portion the term decussation has been applied,

260 Proceedings of the Royal Society.

under the supposition that, though the fibres do intermix, they
still continue onward in their original direction, and that those
from the right side cross over wholly to supply the left eye, while
the right eye is similarly supplied by fibres from the left thalamus.
Anatomists have considered this opinion as confirmed by the cir-
cumstance of the nerves actually crossing each other as two per-
fectly distinct cords in certain fish. ‘The author, however, from a
species of blindness under which he has more than once suffered,
concludes that a different distribution of the nerves takes place
in the human subject. This peculiar state of vision consisted in
seeing only half of every object, the loss of sight being, in both
eyes, towards the left, and of short duration only. In reflecting
upon this subject a certain arrangement of the optic nerves, not
consistent with the generally received hypothesis of their decssa~
tion, occurred to him. Since the corresponding points of the two,
eyes, he observes, sympathize in disease, their sympathy is evi-
dently from structure, and not from mere habit of feeling together.
Any two corresponding points must be supplied with a pair of fila-
ments from the same nerves, and the seat of a disease in which
similar parts of both eyes are affected, must be considered as si-
tuated at a distance from the eyes, at some place in the course of
the nerves where these filaments are still united, and probably in
one or other thalamus. It is plain, therefore, that the cord
which comes finally to either eye, under the name of optic nerve,
must be regarded as consisting of two portions, one half from the
right thalamus, and the other from the left. Upon this supposition
decussation will take place only between the adjacent halves of
the two nerves. That portion of nerve which proceeds from the
right thalamus to the right side of the right eye, passes to its des-
tination without interference; and in a similar manner the left
thalamus will supply the left side of the left eye with one part of
its fibres, while the remaining halves of both nerves, in passing
over to the eyes of the opposite sides, must intersect each other;
either with or without intermixture of their fibres.

Dr. W. observes that the crossing of the nerves to the opposite
eyes in fish, is in conformity with this view of the arrangement of

Proceedings of the Royal Society. 261

the human optic nerves; for in the sturgeon, for instance, the eyes
are placed so exactly back to back, that there are no corresponding
points of vision requiring to be supplied with fibres from the same
nerve. In this animal an injury to the left thalamus might be ex-
pected to occasion entire blindness to the right eye alone; in our-
selves a similar injury would occasion blindness to all objects
situated to our right, owing to insensibility of the left half of the
retina of both eyes. Dr. Wollaston states some other facts, illus
trating his view of this peculiar distribution of the human optic
nerves, remarking that in common vision also the sympathy of cor-
responding points, which receive similar impressions from the same
object, is dependent upon the same arrangement of nerves, to
which the term semi-decussation may be applied. In conclusion,
he observes that, so long as our consideration of the functions
of a pair of eyes is confined to the performance of healthy eyes in
common vision, when we remark that only one impression is made
upon the mind, though two images are formed on corresponding
parts of the retina, we may rest satisfied in ascribing the apparent
unity of the impression to habitual sympathy of the parts. But
when we regard sympathy as arising from structure, and depend-
ent on connexion of nervous fibres, we therein see a distinct origin
of that habit, and have presented to us a manifest cause why in-
fants first begin to give the corresponding direction to their eyes ;
and clearly gain a step in the solution, if not a full explanation, of
the long agitated question of single vision with two eyes.

Thursday, February 26.

A Paper was read, entitled
Experimental Inquiries relative to the Distribution and Changes of

the Magnetic Intensity in Ships of War. By Geo. Harvey, Esq.

This paper contains the details of a number of experiments
made on board several vessels, with a view of determining the in-
fluence of the iron in the ships upon the compass under different
circumstances and situations. The instruments used for deter-
mining the intensity consisted of a magnetized cylindrical bar
2.5 inches long, and ;%; inch diameter, delicately suspended by

262 Proceedings of the Royal Society.

a single fibre of the silk worm to the extremity of an adjust-
ing screw, which worked in the cap of the glass vessel enclosing
the bar. A brass wire also passed through the cap for the pur-
pose of placing the bar at right angles to the magnetic meridian
previous to its being put into a state of oscillation.

On the days devoted to the experiments on ship-board, the
time of making 50 vibrations of the bar was determined in the
centre of a meadow, of which the substratum was clay-slate, by a
mean of 6 sets of experiments, the time being accurately regis-
tered to quarter seconds. The instrument was then taken on
board, and placed in succession at the different stations in the
ship, and the mean of 6 sets of experiments determined at each
station, with the same precaution as on land. The time, says the
author, of performing the oscillations on shore, and at each of the
assumed points in the ship, necessarily gave the magnetic in-
tensity at each station in terms of the terrestrial intensity,
which in this case was represented by 100.

Thursday, March 4.
William Wavell, M.D., and Captain Philip Parker King, R.N.,

were admitted Fellows.
At this Meeting of the Society a Letter from Sir E, Home, ad-
dressed to the President, was read, containing
Some curious Facts respecting the Walrus and Seal, discovered by
the examination of Specimens brought to England in the different
Ships lately returned from the Polar Circle.

The first fact stated by Sir Everard Home in this paper is, the
analogy in structure between the hind foot of the walrus and the
foot of the fly. In both there is a very similar apparatus for pro-
ducing a vacuum, so as to enable the animal to proceed upon
smooth surfaces against gravity by the adhesion of the feet thus
effected, there being 2 cups in the foot of the fly, and one in that
of the walrus for this purpose. Secondly, he notices the peculiar
mode in which the bile in the walrus is collected in a reservoir;
and thence forcibly impelled into the duodenum.

Proceedings of the Royal Society. 263

The third new fact which the author adduces is the peculiar
structure of the funis and placenta of the seal. In this animal
the vessels forming the funis are not twisted; their whole length
is 9inches. Three from the placenta, they give off anastomosing
branches, connected. with it by three membranous folds, between
which the blood vessels are conveyed to the placenta. This struc-
ture gives uncommon facility to the placental circulation, and
makes it worth inquiry whether the same peculiarities exist in
other marine animals. Several illustrative drawings accompany
this paper.

On the same evening a Paper was communicated, entitled
Further Particulars of a Case of Pneumato-Thorax. By J. Davy,
M.D. F.R.S.

About a month after the operation described in Dr. Davy’s
former paper, when the patient appeared to be doing well, symp-
toms of hydro-thorax came on, and fluid again collected in the
left side of the chest;—a second operation therefore was per-
formed, and 14 ounces of fluid discharged through a perforation
in the fifth rib. During the six following weeks not less than 20
pints of fluid ran off through the opening—at first it was transpa-
rent, but became gradually more and more purulent, and was ©
mixed with air composed of oxygen, azote, and carbonic acid, in
various proportions. The patient’s health improved at first pro-
gressively, but in about 6 weeks after the operation he became
worse, and expired suddenly. On examination after death about
6 oz. of pus were found in the left pleura, The right pleura was
healthy, but tubercles and vomice were found in the right lung.
The left lung was much condensed, and communicated by two
small openings with the pleura. Dr. Davy referred the origin of
the disease in this case to a communication between the aspera
arteria and cavity of the pleura, established by the rupture of a
superficial bronchial tube and the membrane covering it; he con-
cluded the paper with some remarks upon the fluctuation and com-
position of the air from the chest, which he attributed not to the
varying quantity of atmospheric air admitted through the per-

264 Proceedings of the Royal Society.

foration, which was as carefully closed as possible, but to its
vitiation by respiration, and by the absorbent power of the pleura,

Thursday, March 11.

A paper entitled Remarks on the Parallax of a Lyre. By
J. Brinkley, D.D. F.R.S., Sc. &c. §c. ,was read.

The author’s object in this paper was principally to form a correct

estimate of the absolute and relative degrees of accuracy of the

instruments at Dublin and at Greenwich. He first considered the

difference of parallax between y Draconis and « Lyre, and

secondly the absolute parallax of « Lyre.

He exhibited in a table the whole of the results of 337 observa-=
tions of Mr. Pond for the intercepted arc, reduced to 1 January,
1815; chiefly by Mr. Pond’s own computaticns. From 46 of the
observations, made in the year 1812, he deduced 0".28 for the co-
efficient of the effect of parallax: and from such of the ob-
servations as were made in the same day the number deduced
is 0”.54.

In 1813 there was a difference of half a second between the mean
of 22 observations in June and July, and of 17 in August; hence
Dr. Brinkley was led to examine the observations of this year
alone, and he found that 61 of them from June to December, as
reduced by Mr. Pond, gave 0”.42 for the co-efficient of parallax:
and omitting the last 5 days of observation 0’.89, whicl. is little
less than the result of his own researches.

On the other hand, when 5 double observations, in January and
February, 1814, were added to these 61, they reduced the result
for the co-efficient to 0”.18. So that the discordances seem to
be too great to enable us to place any reliance on the conclu-
sions respecting the actual magnitude of the annual parallax.

A similar fluctuation is observable in the results obtained for
the following years: and though it might, on the whole, be in-
ferred that the parallax is about 2.as great as that which the
author has assigned from his own observations, yet he contents
himself with concluding that the mural circle of Greenwich has
not sufficiently proved the identity of the distance of the two stars

Proceedings of the Royal Society. 265

in summer and winter within one-tenth of a second: but, on the
contrary, that it shews the parallax of « Lyre to be half a second
greater than that of y Draconis.

In 1815, the first 15 summer observations, compared with the
first 13 in November, give a parallax of + 0".72; the next 16 in
summer, compared with the next 16 in winter, give a negative
parallax of — 0”.58 ; a comparison which sufficiently proves the
imperfection of the observations, depending probably on an un-
steadiness in the instrument.

In the whole five years the mean of all the observations in
August exceeds the mean of July by 0".51; a discordance which
parallax would diminish but in an inconsiderable degree.

The author pursued a similar train of argument in the second
part of the inquiry, relating to the absolute parallax of a Lyre.
While the circle at Dublin, he observes, made from a mean of
several years the double zenith distance of this star 3” greater
in the beginning of December than in the beginning of August,
that of Greenwich shews no difference whatever in the double
altitude observed by reflection in summer and winter. There are,
however, differences of above 4 seconds in the difference of alti-
tude of Lyra and of the Pole-star, as determined in different
years by the same instrument: and Dr. Brinkley observed, that an
unsteadiness, amounting to 15” or 20”, is discoverable in the
comparative results of the different microscopes ; whence he infers
that there must be an uncertainty, amounting to many tenths of a
second, in the mean.

The co-efficients of aberration and of solar nutation, which
come out 20".35 and 0".51, are certainly true to } or 1; of a
second, as deduced from the observations of Dublin: the author
thinks it therefore fair to infer that 1.14, the co-efficient of
annual parallax for « Lyre, is correct nearly in the same pro-
portion. Nor are there any changes from season that could pro-
duce the appearance of regular parallax of all the stars in which
it has been inferred: and it is very improbable that any error of
the instrument could have given a parallax to Lyra, and left the
Pole-star completely free from it.

266 Proceedings of the Royal Society.

‘The last of the tables shew the consistency of the circle of
Dublin in the places of the stars as determined by it after the in-
terval of a considerable number of years, without any such ten-
dency to the south, as is supposed to have been observed at
Greenwich.

Thursday, March 18.

An Account of Experiments on the Velocity of Sound, made in Holland,
by Dr..G. Moll and Dr. A. Van Beck, was communicated to the
Society.

After noticing the difference between the celerity of sound, as

deduced by theory, and found by experiment, and La Place’s

explanation of the cause of that difference, and his corrections of
the Newtonian formula, the authors proceeded to consider the in-
fluence of the variable force of wind upon its velocity, and state
their mode of annihilating such cause of error, They then detailed
their own experiments, for which they selected two open and
elevated spots in the plains of Utrecht, distinctly visible from each
other, and distant about 96.64 fathoms: they measured the interval
between seeing the light and hearing the sound, by clocks, with
conical pendulums, which divide the 24 hours into 10 million
parts, andone of the indexes of which give ;4, part of a decimal
second. Each station was also furnished with a good barometer,
several accurate thermometers and excellent telescopes, and the
humidity of the air was determined by Daniell’s hygrometer.: The
authors then described the means which they adopted to ensure the
simultaneous firing of the shots at both stations, and by which
they succeeded in bringing them within 1” or 2” of each other, and
entered at considerable length into the details of their different ex-
periments, the results of which are given in several tables annexed
to this paper, among which will be found one, exhibiting a general
view of the results of the experiments of those different philosophers
who have investigated this subject.

In conclusion, it appears from their researches that at the tem-
perature of 32° the velocity of sound is 1089.7445, English feet
per sexagesimal second,

Proceedings of the Royal Society: 267

At this meeting the Lord Bishop of Limerick was admitted a
Fellow of the society.

Thursday, March 25.

Major-General Sir John Malcolm, G.C.B., was admitted into
the society.

A Letter from the Rey. L. W. Dillwyn to Sir H. Davy, Bart. P.R.S,
was read.

This letter was supp/ementary to a former one, and contained
further observations on the relative periods at which the different
families of testaceous animals appear to have been created, and on
the gradual approximation which may be observed in British
strata, from the fossil remains of the oldest. formations to the living
inhabitants of our present land and waters.

The author observes that the dimyairia of the strata between the
transition lime and lias have the ligament external, and that in-
ternal ligaments were therefore confined to the monomyairia till
after the deposition of the lias.

In the beds above the lias, all the shells are referable to existing
orders of animals, and it is only in the tertiary beds that any of
the cirrhipeda, or families of the naked mollusca nave been found,

What is generally considered as the beak of a sepia, Mr. Dill-
wyn refers to the cephalopode animal of an ammonite. Every
shell of the tertiary strata, the author observes, may be referred to
some existing genus; but though this approximation has thus far
proceeded in the London clay, yet its numerous species are now.
extinct, and it is only in the upper beds of crag that any fossil can
be completely identified with a living species.

A letter from Mr, Tredgold to Dr. Thomas Young was also read,
containing,
An Account of his Experiments on the Elasticity and Strength of hard
and soft Steel.
The bars of steel used in these experiments were supported at
the ends by two blocks of cast iron, resting upon a wooden frame,

268 Proceedings of the Royal Society.

and a scale for weights was suspended from the middle of the
length of the bar, by a cylindrical steel pin, 2 inch diameter. To
measure the flexure, a quadrantal piece of mahogany was attached
to the frame with a vertical bar sliding in two guides at its edge,
and moving an index. The bar and index were so balanced, that
one end of the bar bore with constant pressure upon the specimen,
and the graduated arc was divided into inches, tenths, and
hundredths, and thousandths were measured by a Vernier. Abar
of blistered steel, of file hardness, 13 inches long between the
supports, underwent no permanent alteration of form when loaded
with 110lbs. The temper of the bar was then successively lowered,
and it was ultimately again hardened, but in these different states
its flexure and resistance to permanent change of form remained
the same. These experiments were repeated with bars of other
dimensions, which were loaded till they broke, and from them the
author also infers that the elastic force of steel is not altered by
temper, and that the force which produces permanent alteration is
to that which causes fracture in hard steel, as 1 : 1.66, and in the
same steel, of a straw-yellow temper, 1: 2.56. From comparisons
of the strain required to cause permanent alteration in different
kinds of steel, the author concludes, that in the process of hard-
ening, the particles are put into a state of tension among themselves,
which lessens their power to resist extraneous force, and the phe-
nomena of hardening may be referred to the more rapid abstraction
of heat from the surface of the metal, than can be supplied from
the internal parts; whence a contraction of the superficial parts
round the expanded central ones, and a subsequent shrinking of
the latter, by which the state of tension is produced.

Thursday, April 1, and Thursday, April 8.

The following papers were read:

A Comparison of Barometrical Measurement with the Trigonometrical
Determination of a Height at Spitzbergen. By Capt. Edward
Sabine, F. R. 8.

The hill selected’ for this comparative measurement was the

highest within convenient distance, of which the ascent was prac-

Proceedings of the Royal Society. 269

ticable, on the western part of the N.coast of Spitzbergen. The
summit was less than two miles from the observatory, in a direction
nearly due south; the observatory being upon an island rather
more than a mile from the main land. In consequence of the
extreme inaccuracy of the plan of Fairhaven, published in Captain
Phipps’ voyage, the author annexed to this paper a sketch of
the harbour and adjacent coast, to shew the positions of the hill and
observatory. The small bay formed by the shore of the main
land to the north eastward of the hill being frozen over, afforded a
perfectly level base, and corrections for inequality were thus ren-
dered unnecessary. A polished copper cone was fixed upon a staff
at the summit of the hill, the apex of which was proposed as the
height to the measured; it stood 44 inches above the highest
pinnacle of the summit. Captain Sabine then entered into the details
of this trigonometrical measurement, from which the altitude of the
cone is considered as = 1644 feet. The author next proceeded to
detail the particulars of the barometrical measurement, and the
precautions taken to ensure accuracy in the instruments, and in
their employment; and the height of the cone, thus ascertained,
was 1640.07 feet. .

Captain Sabine concluded this paper with some remarks upon
the incorrectness with which the heights of the hills on this coast
are set down in Captain Phipps’ voyage.

An Inquiry into the nature of the luminous power of some of the
Lampyrides ; namely, the L. Splendidula, L. Italica, and L. Noc-
tiluca. By T.J.Todd, M.D. Communicated by Sir E. Home,
Bart. V.P. R.S.

After adverting to the various opinions entertained respecting
the luminous powers of these insects and to some of the more usual
phenomena which attend the emission or production of their
light, the author proceeded to describe their structure, especially in
relation to their luminous organs. ‘The peculiar matter in which
the power of emitting light appears to reside, is adhesive, semi-
transparent, and granulated. According to Macaire, it is thickly
penetrated by neryous filaments, and loses its luminous property
Vou, XVII. U

270 Proceedings of the Royal Society.

when broken down. The longest period which the author has ob-
served the amputated organ to continue luminous is 20’, and it
continues to shine in media of very different properties, in vacuo,
under mercury, in water, and in oil. The light is re-excited by
certain irritants ; by heat and cold, by friction and by galvanism,
by alcohol, camphor, and ammonia. In the living animal, also,
mechanical and chemical stimulants excite the appearance of the
light provided they do not disorganize the part. When the animals
are killed by alcohol, tincture of hellebore, or of nux vomica, and.
certain other poisons, after all light and life have ceased, another
fixed and steady light appears in the organ, varying in duration
from 12 hours to 4 days. From the general results of his obser-
vations, the author concludes that the luminous powers of these
insects are exclusively referable to vital action, and that their
use has not been accurately ascertained, though probably con-
nected with sexual distinction. .

Sir F. Shuckburgh, Bart. was admitted a fellow.

The society then adjourned over two Thursdays, to meet again
on the 29th of April.

Thursday, April 29.
The Rey. Dr. Maltby and E. H. Lushington, Esq. were admitted
Fellows.
A letter from Dr. Tiarks to Dr. Young was read, containing

A short Account of some Observations made with Chronometers,
in two Expeditions sent out by the Admiralty, at the recommenda-

tion of the Board of Longitude, for ascertaining the Longitude
of Madeira and of Falmouth.

Dr. Tiarks was sent out to Madeira, in the year 1822, with
fifte.2 chronometers, of which the rates had principally been as-
certained in the Royal Observatory at Greenwich; he touched at
Falmouth both in going out and in returning; and having again
ascertained the rates of his time-keepers, he was thus enabled to
obtain two distinct determinations of the longitude of Falmouth,
which differed about four seconds of time from that which had been

Proceedings of the Royal Society. 271

inferred from the trigonometrical survey of Great Britain. It be-~
came, therefore, desirable that some further operations should
be undertaken for the removal or elucidation of this discordance,
and the following year a similar method was adopted with twenty-
five chronometers, for determining the difference of longitude be-
tween Falmouth and Dover; this latter station having been chosen
as easy of access, and as being perfectly determined ; and the
computations were made by interpolation, without employing any
other rates for the chronometers than those which were observed
in the different trips while they were actually on board of the ship ;
and latterly, when Dover Roads became unsafe, the operations
were limited to the distance from Portsmouth to Falmouth: thus
between the months of July and September the observations were
made three times at Dover, four times at Falmouth, and three
times at Portsmouth: and the comparison of their results affords
a correction of five seconds of time for the difference of longitude
of Dover and Falmouth, and of three for the difference of Fal-
mouth and Portsmouth, agreeing completely with the error of four
seconds attributed, from the observations of the preceding year,
to the difference of longitude of Falmouth and Greenwich.

Hence Dr. Tiarks thinks it fair to conclude, that the diameter of
the parallel circle on which the longitude is measured has in the sur-
vey been taken somewhat too great, and consequently the earth’s el-
lipticity greater than the truth. He remarks, that the measurement
of the spheroidical triangle concerned, determines only the actual
flatness of the part of the earth’s surface on which it is situated, and
not the actual magnitude of the whole parallel, unless its curvature
be supposed perfectly uniform, which we cannot assume with confi-
dence: while, on the other hand, if we compute the ellipticity
from the result of the chronometrical determination, it becomes
si, instead of ;4,, and agrees with the most accurate measure~
ments obtained from different principles. The longitude of Fal-
mouth is finally determined to be 20 minutes, 11.1 seconds of
time, and that of the British Consul’s garden at Funchal, 1 hour,
7 minutes, 39 seconds, west of Greenwich.

U2

272 Proceedings of the Royal Society.

Thursday, May 6.

Lieutenant Henry Forster, R.N., was elected a Fellow of the
Society, and being about to leave England on the Polar Expedi-
tion under Captain Parry, he was immediately admitted by the
President.

The following papers were read :—

On Univalves. By Charles Collyer, Esq. Communicated by Sir
James Macgrigor, F.R.S.

In this paper the author entered into a series of details respecting
the structure of shells, and the anatomy of their inhabitants,
which he thinks suggest the necessity of separating the natural
history of the former from that of the latter. By parts peculiar to
univalves, he proposed to distinguish and nominate families, to
divide into sub-genera such as are distinguished by an uniform
state of the more general feature, and to separate into individuals,
such as with this particular state have additional parts, or modi-
fications of such parts. To render the nomenclature perspicuous, he
suggested Latin derivations of one termination, expressing some es-
sential distinctive feature, or difference of colour or size; and where
these fail, he had recourse to similitudes with other objects. The
parts or conditions chosen for generic distinction and denomina-
tion, are cavity, lip, columella, rostrum, and spire, open, tubular.
The application of these principles of distinctive description was
illustrated by reference to several individuals, such as Argonauta,
Cyprea, Conus, Trochus, and others. Shells that are partly or
completely open and flat present, said the author, no feature for
association, and:-hence a condition must be chosen, namely, the
presence or absence of a margin. Lastly, the author divided tu-
bular shells into straight and open, straight and closed, and con-
torted.

Of the effects of the density of Air on the Rates of Chronometers.

By George Harvey, Esq. Communicated by D. Gilbert, Esq.,
F.RS.

Among the sources of error to which chronometers are liable,

Proceedings of the Royal Society. 273

the effect of the variable density of the medium in which the ba-
lance vibrates has been overlooked, the author, therefore, pro-
poses to investigate the effects of diminished and increased pres=
sure, of transference from one to the other, and of the ordinary va-
riations of atmospheric density upon the rates of chronometers.

In respect to diminished pressure he found that chronometers
gained by being placed in air of less density than that of the ordi~
nary state of the atmosphere, and that on the other hand they
lost when subjected to air of greater than ordinary density. These
experiments were made with a variety of chronometers, placed in
the receiver of an air pump, or in that of a condensing apparatus.

In respect to the influence of ordinary changes in the density
of the air, the author remarks that pocket chronometers are more
readily affected than box chronometers, but that they all exhibit
an increased rate under diminished density, and vice versd.

The author shews that these changes in the rates, as observed
in the air-pump and condensing apparatus, are independent of the
changes of temperature resulting from changes in the density of
the air thus rapidly effected, and therefore proceeds to inquire
into the actual cause of the changes which his experiments indi-
cate; he refers them to an increase in the arc of vibration when
the density is diminished, and to a diminution in the arc, under —
increased density.

Thursday, May 20.
The Rey. Baden Powell was admitted a Fellow.

A Letter was read
To the President from Professor Berzelius, dated Stockholm,
April 21, 1824,

In this letter Professor B. announces his discovery of a combi-
nation in a mineral, of chloride and oxide of lead, in the pro-
portion of one atom of the former to two of the latter. He states
that he has verified Mr. Phillips’s researches on uranite, and gives
a somewhat detailed account of his experiments on fluoric acid,
and of the properties of the base of silica, which he procured by

274 Proceedings of the Royal Society.

heating potassium with dry fluosilicate of potassa, by which a sili-
curet of potassium and fluate of potassa are formed; and
which, when thoroughly washed with water, leaves a residue of
hydroguret of silicium. It burns imperfectly in air and oxygen,
at a red heat; is of a brown colour, and is acted upon by no acid
except the fluoric. Silicium is readily oxydized when heated
with carbonate of potassa or of soda, 100 parts producing 208
of silica. It burns in the vapour of sulphur, producing a white
substance, which yields sulphuretted hydrogen when thrown into
water, and silica remains in solution. In chlorine silicium burns
at a red heat, and yields a colourless liquid chloride, the odour of
which resembles that of cyanogen. In its nascent state silicium
appears to combine with the metals.

This letter concludes with some remarks upon zirconium, ob-
tained by the action of potassium on the alkaline fluate of zir-
conia; it is black, feebly acted upon by nitro-muriatic acid, so-
luble in sulphuric acid, and readily so in fluoric, with the disen-
gagement of hydrogen. It unites with sulphur and chlorine, and
readily burns in the air at a heat below redness,

Thanks ordered,

Thursday, May 27.

A paper by Dr. Wollaston was read, —
On the apparent Direction of the Eyes in a Portrait.
Our account of this paper must necessarily be very imperfect,
for want of the very curious and interesting drawings which ac-
companied it. Dr. W. observed that when we consider the pre-
cision with which we commonly judge whether the eyes of another
person are fixed upon ourselves, it is surprising that the grounds
of such judgment are not distinctly known, and that most per-
sons in attempting to explain the subject would overlook some of
the circumstances by which they are generally guided. Though it
may not be possible to demonstrate by any decisive experiment on
the eyes of living persons what those circumstances are, we may
find convincing arguments to prove their influence, if it can be
shewn, in the case of portraits, that the same ready decision that

Proceedings of the Royal Society. 275

we pronounce on the direction of the eyes is founded in great
measure on the view presented to us of parts which have not been
considered as assisting our judgment.

Dr. W. then adverted to the influence cf the form of the iris as
announcing the direction of the eye in portraits, and to that of the
variable portion of the white shewn when the eye is variously di-
rected in living persons; he remarked, however, that even in real
eyes we are not guided by this circumstance alone, but are un-
consciously aided by the concurrent position of the face; and he
illustrated this opinion by reference to a series of drawings
above mentioned, shewing that the apparent position of the
eyes is powerfully influenced by that of the adjacent parts of
the face, especially those which are most prominent: and these
considerations are not limited in their application merely to cases
of lateral turn of the eyes or face, but the same principles also
apply to instances of moderate inclination of the face upwards or
downwards; for when the face is directed downwards, the eyes
that look at us must be turned upwards from the position of the
face to which they belong; and if to eyes so drawn an upward
cast of features be substituted for the former, the eyes imme-
diately look above us.

From these and other details given in the paper, the author
concludes that the apparent direction of the eyes to or from the
spectator depends upon the balance of two circumstances com-
bined in the same representation; namely, 1. The general po-
sition of the face presented to the spectator. 2. The turn of the
eyes from that position; and thence proceeds to examine why, if
the eyes of a portrait look at the spectator placed in front of
the picture, they appear to follow him in every other direction.
When two objects are seen on the ground at different distances
from us in the same direction, one appears and must be repre-
‘sented exactly above the other, so that a vertical plane from the
eye would pass through them, and since such a line will be seen
upright, however far we move to one side, it follows that the
same objects still seem to be in a line with us exactly as in

276 Proceedings of the Royal Society.

the front view, seeming, as we move, to turn from their first
direction.

In portraits, the permanence of direction, with reference to the
spectator, and corresponding change of its apparent position in
space when he moves to ejther side, depends upon the same prin-
ciples. The nose drawn in front with its central line upright
continues directed to the spectator though viewed obliquely ; or if
the right side of the nose is represented, it must appear directed
to the right of the spectator in all situations; and eyes that turn
in a due degree from that direction toward the spectator, so as to
look at him when viewed in front, will continue to do so when
viewed obliquely.

On the same evening was read,

New Phenomena caused by the Effects of Magnetic Influence. By
Mr. Abraham.—Communicated by Mr. W. Tooke, F.R.S.

In this paper Mr. A. detailed a series of experiments upon the
passage of electricity through magnetized steel bars, which lead
him to conclude that they possess a much better conducting power
than the same bars in their comnfon state, and consequently that
they are better adapted for the preservation of buildings from
lightning. On bringing one point of a magnetic discharging rod
to the negative side of a charged jar, and presenting the other to
the positive ball, he observed a deep red light between them,
which he ascribes to the contact of the condensed magnetic and
and electric atmospheres surrounding the ball and point.—
Mr. Abraham concluded his paper with some observations upon
certain atmospheric phenomena, especially relating to the Aurora
Borealis, which he is inclined to ascribe to the joint influence of
the electric and magnetic powers.

Thursday, June 3.

Dr. John Thomson of Edinburgh, was elected into the Society.
Charles Lemon, Esq., was admitted a Fellow.

Proceedings of the Royal Society. 277

A Paper on the Generation of Fishes, by Dr. hPa Prevost, was
read.

The principal object of this paper was to describe the devolope-
ment of the foetus of the bull’s-head, or miller’s-thumb (cotus
gobio). »

The testicles are composed of a congeries of small canals, ter-
minated at the upper part by ceca, and containing the semen,
which they discharge into a common canal opening into the meatus,
by which the urine is discharged. Under the microscope the semen
appears composed of globules and animalcules. The eggs of the
female are emitted covered with mucus, which swells up when it
absorbs water. The yolk is enveloped in a fine membrane, ad-
hering to which is a white granulated cicatricula, not visible be-
fore foecundation.

The description of the developement of the foetus given by the
author is not intelligible without the annexed plate.

The Society then adjourned over one Thursday, to meet again on

Thursday, June 17;

at which meeting Lovell Edgeworth, Esq., was admitted a Fellow;
and the following papers were read:

On the Action of finely-divided Platinum on Gaseous Mixtures, and
its application to their Analysis, By W. Henry, M.D., F.R.S,

In the first section of this paper the author described the action
of finely-divided platinum, at common temperatures, on mixtures
of hydrogen and olefiant gas with oxygen; of hydrogen and
carburetted hydrogen with oxygen; of hydrogen and carbonic
oxide with oxygen; of hydrogen and cyanogen with oxygen; of
carbonic oxide and carburetted hydrogen with oxygen; of hydro-
gen, carburetted hydrogen, and carbonic oxide with oxygen; and
of the same with the addition of olefiant gas. From the experi-
ments detailed under these several heads, it appears that when the
compound combustible gases mixed with each other, with hydrogen,
and with oxygen are exposed to platinum balls or sponge, the
seyeral gases are not acted upon with equal facility, but that, next

278 Proceedings of the Royal Society.

to hydrogen, carbonic oxide is most disposed to unite with oxygen;
then olefiant gas, and lastly carburetted hydrogen. By due regu-
lation of the proportion of hydrogen, the author remarks that it is
possible to change the whole of the carbonic oxide into carbonic
acid, without acting on the olefiant gas or carburetted hydrogen ;
he observes, however, that, with respect to olefiant gas, this ex-
clusion is attended with some difficulty, and it is generally more
or less converted into carbonic acid and water,

The second section of this paper related to the action of finely-
divided platinum upon gaseous mixtures at 7xcreased temperatures.
In these experiments the gases mixed with oxygen enough to sa-
turate them, were severally exposed in small retorts containing a
platinum sponge, and immersed in a mercurial bath to a tempera-
ture which was gradually raised till the gases began to act on each
other. It was thus found that carbonic oxide began to be con-
verted into carbonic acid at about 300°; olefiant gas was decom-
posed at about 500°; carburetted hydrogen at a little above 555° ;
and cyanogen appeared to require a red heat.

Muriatic acid mixed with half its volume of oxygen began to be
acted upon at 250°; and ammoniacal gas, with an equal volume
of oxygen, at 380°.

Adverting to the property inherent in certain gases of retarding
the action of the platinum when they are added to explosive mix-
tures of oxygen and hydrogen, Dr. Henry observed that it is most
remarkable in those which possess the strongest attraction for
oxygen, and that it is probably to the degree of this attraction,
rather than any agency arising out of their relations to caloric,
that we are to ascribe the various powers which the gases manifest
in this respect.

Dr. Henry concluded this communication by pointing out the
best methods of analyzing mixtures of the combustible gases in
unknown proportions,

An Account of the Organs of Generation of the Mexican Proteus in
a developed state. By Sir E. Home, Bart., V.P.R.S.

The specimens described in this paper were taken in the month

Proceedings of the Royal Society. 279

of June, in a lake three miles from Mexico, at an elevation of
8,000 feet above the level of the sea; the usual temperature of the
lake is 60°, and they are in such abundance as to form a principal
article of food of the peasantry.

By the assistance of a series of annexed drawings by Mr. Bauer,
Sir Everard fully describes the male and female organs of these
animals, and is enabled to decide that they are a full grown and
perfect tribe. ‘“ The attack therefore,” says the author, ‘‘ made
upon Mr. John Hunter’s sagacity, by M. Rusconi, in his work Sur
les amours des Salamandres aquatiques, retorts upon himself.”

On the Effects of Temperature on the Intensity of Magnetic Forces,
and on the Diurnal Variation of the Terrestrial Magnetic Inten-
sity. By 8. H. Christie, Esq. M. A.

The details of the author’s experiments upon the above subjects are
given in an extended series of tables. Commencing with a tem-
perature —3° F. up to 127°, Mr. Christie found, that as the
temperature of the magnets increased, their intensity diminished,
in direct contradiction to the notion of destroying magnetism by
intense cold. From a temperature of 80° the intensity decreased
rapidly as the temperature increased, and at above 100°, a portion
of the power of the magnet was permanently destroyed.

Additional Experiments and Observations on the Application of
Electrical Combinations to the Preservation of the Copper Sheathing
of Ships, and to other Purposes. By Sir H. Davy, Bart. P.R.S

Since his former communication, the President has had an oppor-
tunity of pursuing his researches upon the above subjects, upon an
extended scale, and with results perfectly conclusive and satis-
factory. He found that sheets of copper defended by from +35 to
azhy part of zinc or iron, exposed for many weeks to the full flow of
the tide in Portsmouth harbour, suffered no corrosion, and that
even -y'y¢ part of cast iron exerted great protecting influence,

280 Proceedings of the Royal Society.

Boats, and the sides of ships, protected in this way, were also
similarly preserved.

Of the different protecting metals, cast iron is most convenient,
and the plumbaginous substance formed upon it does not impede
its electrical action. The President formerly anticipated the de-
position of earthy substances upon the negative copper, and this he
now found to take place upon sheets of copper exposed about four
months to sea water, and defended by from ;/, to J their surface
of zinc and iron; they became coated with carbonate of lime and
magnesia; but this effectis easily prevented, by duly diminishing
the proportion of the protecting metal, so as to prevent the excess
of negative power in the copper which then remains bright and clean.

The author observed that many singular facts had occurred in
the course of his researches, some of which bore upon general
science. Weak solutions of salt act strongly upon copper, but
strong ones do not affect it, apparently because they contain little air,
the oxygen of which seems necessary to give the electro-positive
power to these menstrua. Upon the same principle, alkaline solu-
tions and lime-water prevent the action of sea-water on copper,
having in themselves the positive electrical energy which renders
the copper negative.

The President concluded this paper with some further applica-
tions of electro-chemical theory to the subject of it, and referred to
the principles developed, as suggesting means of preserving instru-
ments of brass and of steel, by iron and by zinc, a circumstance
already taken advantage of by Mr. Pepys, in enclosing delicate
cutting instruments in handles or cases lined with zinc.

The Society then adjourned for the long vacation,

281

Art. XI. Proceedings of the Royal Institution, 1824.

Tue Lectures were commenced in the Amphitheatre of this Institution
on Saturday, the 7th of February, when an introductory discourse
was delivered by Mr. Brande.

The following arrangements in respect to the Lectures were an-
nounced to the Members and Subscribers.

On Electricity, Electro-Chemistry, and Electros-Magnetism. By
William Thomas Brande, Esq., F.R.S. London and Edinburgh, Pro-
fessor of Chemistry to the Royal Institution. This Course of Lec-
tures will comprise an experimental Illustration of the Elementary
doctrines of Electricity bearing upon its applications to Chemical
Science and to the Theory and Phenomena of Magnetism. To com-
mence on Saturday the 7th of February, at Two o’Clock, and to be
regularly continued on each succeeding Saturday, at the same hour,
till further notice.

On the leading Subjects of Mechanical Philosophy, and their recent
Improvements, particularly Optics and Hydraulics. By John Mil-
lington, Esq., F.L.S., Sec. Astron. Society, &c., Professor of Me-
chanics to the Royal Institution. To commence on Thursday the 12th
of February, at Two o’Clock, and to be regularly continued on each
succeeding Thursday, at the same hour, till further notice.

On Botany, with the Principles of Vegetable Physiology. By
John Frost, Esq., Professor of Botany to the Medico-Botanical So-
ciety of London. ‘To commence after Easter.

On Plane Geometry. By John Walker, Esq., formerly Fellow of
Trinity College, Dublin, and M.R.I.A. To commence after Easter.

On Music. By W. Crotch, Mus. D., Professor of Music in the
University of Oxford. To commence after Easter,

On Zoology, comprehending a Survey of the Class Mammalia.
By J. Harwood, M.D., F.L.S.

On European Literature. By the Marquis Spineto.

On Genealogy. By Banks, Esq.

On the Objects of Vegetable Chemistry, and the applications of

282 Proceedings of the Royal Institution.

Chemical Science to the elucidation of Vegetable Physiology. By
W.T. Brande, Esq., F.R.S., and Prof. Chem. R.I.

The following are such of the Prospectuses of these Lectures, as
have been published ;

Prospectus or Mr. Branve’s Lectures on ELECTRICITY.
Lecture I. Saturday, February 7.

History of Electricity, with experimental Illustrations. Account
of the electrical and magnetical Discoveries of Dr. Gilbert. Re-
searches of Wall, Hauksbee, Grey, Wheeler, and Watson. Theories
of Electricity. Galvani’s Experiments. Volta’s Inquiries. Sketch
of Sir H. Davy’s Discoveries in relation to this subject, and of their
influence upon the progress of electrical and chemical Science.
CErsted discovers the electrical production of Magnetism.

Lecture Il. February 14.

An inquiry into the present state of the Theory of Electricity.
Imperfection of all the hypotheses. Of the validity of Coulomb’s
Deductions. Phenomena of attraction and repulsion exhibited and
explained in reference to the hypotheses of Du Fay, and of Franklin.
Of Electroscopes and Electrometers. Investigations of Zpinus, Of
Conductors and Nonconductors. History of the Electrical Machine—
its various constructions, and their respective advantages. Analogies
between the phenomena of Electrical and of Magnetic Attraction.

Lecture III. February 21.

Of the luminous appearances connected with Electrical Excitation.
Electric Spark in various media. Electrified Points. Of induced
Electricity, and of the Phenomena exhibited by Conductors of vari-
ous kinds when under the influence of electrical induction. Of the
Electro-Polar State. Of the causes of the accumulation and dis-
charge of Electricity. Extensive Induction exhibited in the spiral
tube and Juminous words. Induction through air, glass, mica, lac,
other media.

Lecture IV. February 28.

On the construction and theory of the Leyden Phial. Dr. Frank-

Proceedings of the Royal Institution. 283

lin’s Views. Polarity of a series of Jars. Electrometers applicable
to measuring the intensity of the charge of a Jar. Experiments in
reference to the Theory of the Leyden Jar. Magnetic Phenomena
analagous to those of induced electricity. Of the Electrophorus, and
the permanent source of its electricity—states of the upper and lower
plates. Of Electrical Batteries.

Lecture V. March 6.

Excitation of Magnetism observed in wires transmitting electricity ;
independent effects of quantity and intensity. Experiments on the
perforation, disruption, and ignition of various substances by Elec-
tricity. Experiments of Cavendish, Priestley, Bennet, and Volta, in
relation to the Chemical agencies of Electricity. Dr. Wollaston’s
Researches upon this subject. Natural phenomena dependent upon
or connected with Electrical Excitation. Applications of Conductors
to houses, steeples, ships, and powder magazines.

Lecture VI. March 13.

Recapitulation of the principal subjects discussed in the preceding
Lectures, as illustrating other sources of Electricity, and especially
that of the contact of dissimilar metallic and other conducting bodies.
Experiments of Galvani—of Volta. Construction of the Voltaic
Pile—the Couronne des Tasses—the Battery. De Luc’s Electrical
Column—its importance in demonstrating the source of electricity in
Volta’s Pile. Influence of chemical agents in these arrangements.
Sir H. Davy’s early Discoveries in this department of science. In-
fluence of the size of the plates, and of their number upon the electric
excitement.

Lecture VII. March 20.

Proofs of the identity of Voltaic and common Electricity. Various
forms and constructions of the Pile and Battery. Best construction
suggested by Dr. Wollaston, Experiments on the ignition and fusion
of substances with large Voltaic Batteries. Various causes which
influence the conducting powers of Metallic Wires referred to in
illustration of Sir H. Davy’s Researches, Passage of Voltaic Elec-
tricity through a vacuum.

284 Proceedings of the Royal Institution.

Lecture VIII. Murch 27. a

Hypothetical Views in reference to the relation subsisting between
heat, light, electricity, and magnetism. Usually received Theories
of light and heat—their insufficiency. Of the Calorimotor and Mag-
netomotor. Electricity considered as a chemical agent. Early ex-
periments of Nicholson, Carlisle, and Cruickshank. Series of expe-
riments in illustration of Sir H. Davy’s discoveries, commencing with
those respecting the source of acid and alkaline matter in water, and
terminating with the discovery of the nature of the Earths, fixed alka-
lies, and other substances. His application of a negative power to
the prevention of the corrosion of the copper sheathing of ships.

Lecture IX. 4pril 3.

Of the Electro-magnetic Discoveries of M. CEirsted. Positions
assumed by magnets is respect to wires transmitting electrical currents
in different directions. Dr. Wollaston’s hypothesis of the cause of
these phenomena explained by experiments and models. All metals
susceptible of magnetism, but no other substances. Effect of Spirals.
M. Ampere’s experiments and apparatus. Modes of conferring
permanent magnetism upon steel bars. Mr. Faraday’s inquiries con-
nected with this subject—first effects electro-magnetic rotation—his
apparatus. Various means of exhibiting electro-magnetic rotations
Conclusion of the Course.

Sy3LbLaBus oF a Course or LecturzEs ON Botany.
By Mr, Frost.

Lecture I. Wednesday, May 26.

Introductory Remarks on Vegetable Physiology. The Analogy be-
tween Plants and Animals considered. Definition of a Plant. Ob-
servations on the Textures and Vessels of which it is constituted.
Examination of the component parts of the Trunk, viz., the Epi-
dermis, the Cortex, the Liber, the Alburnum, the Wood, and the
Medulla.

Lecture If. Wednesday, June 2.

Consideration of the Sap and the Juices of Plants, The effects of

Proceedings of the Royal Institution. 285

Light and Heat on Vegetables. Remarks on the Germination of
Seeds, with the progress of the Corculum or Embryo. Use of the

Cotyledons.
Lecture III. Wednesday, June 9.

Examples of Ascidia, or hollow-foliaceous Appendages. Re-
marks on the various kinds of Stems, e. g., the Scape, Peduncle,
Culm, &c. Tilustrations of the Linnean System.

Lecture IV. Wednesday, June 16.

Further Examples of the Artificial System. Remarks on the Na-
tural Arrangement of Plants. Conclusion of the Course.

SYLLABus oF Mr. WaLKER’s LECTURES ON PLANE GEOMETRY.
ge The numeral references are to the Propositions in the
Elements of Euclid.

Preliminary Remarks and Definitions.

Lecture I. §i. Monday, May 10.
Elementary Doctrine of Angles. /
Prop. 13, 14, 15, El. Remarks. on the Doctrine of Parallels.
Prop. 29, 28, 27, El. Corresponding subtenses of Angles a test of
their equality or inequality. Prop. 4, (first part) 24, 25, El.

Lecture IT. § ii. Monday, May 17.

Elementary Doctrine of Triangles.

Prop. 32, El. and Corollaries. Three cases of identical Triangles.
Prop. 4, 8, 26, El. Prop. 5,6, 18,:19, El. Prop. 20, El. . The
line drawn from the right angle of a right-angled triangle to the middle
point of the hypotenuse is equal to half the hypotenuse.

Lecture II. §iii. Monday, May 24.

Elementary Doctrine of Parallelograms.

Prop. 33, 34, 35, 36, 37, 38, 39, 40, 41, El. Converse of Prop.
34. Prop. 43, El. A parailelogram is bisected by any line drawn
through the middle point of its diagonal. Prop. 2, 3, 4, 7, El. b, il.

Lecture IV. §iv. Monday, May 31.

Doctrine of ‘Triangles, continued.
Vox, XVII. ».4

286 Proceedings of the Royal Institution.

Prop. 2. El. b. vi. as far as itextends to commensurable lines. The
three lines drawn from the angles of a triangle to the middle points
of the opposite sides have a common point of intersection. Also,
the three lines bisecting the angles of a triangle. Prop. 47, 48. El.
Pappus’s Theorem. Prop. 12, 13. El. b. ii.

Monday, June 14, § vy. Problems.

Sy.iasus or a Course or Lectures on ZOOLOGY, COMPRE=
HENDING A SURVEY OF THE CLass Mammatia. By J. Har-
woop, M.D., F.L,S., &c.

Lecture I. Wednesday, April 28.

Introductory Observations. Necessity of systematic arrangement

in the study of Animated Beings. The bony fabric in Quadrupeds.

Division of the Mammalia.

Order Ist. The Ape tribes, or Quadrumana; their curious adap-
tation in form and structure to their natural habits and economy.
The Ourang Outang. Peculiarities in form, character and manners
in African Monkeys. Baboons, American species, Lemurs. Ga-
lago, &c.

Order 2d. The Beasts of Prey or Carnivora; their diversity in
form and habits; perfection of their senses; relative powers of
destruction; modes of attack. The Bats. Other insectivorous

Quadrupeds.
Lecture II. Wednesday, May 5.

Carnivorous Animals continued, Bears. Dogs. Hyenas. Feline
tribes. Geographical distribution of species. Amphibious Qua-
drupeds. Seals. Walruses, &c. Extinct fossil species of the Car-
nivora. Caves in Germany containing them. Manner in which
their remains are deposited. Kirkdale Cave.

Order 3d. The Gnawing Animals, or Rodentia. Peculiarities in
the formation and habits of the principal genera.

Lecture HII. Wednesday, May 12.
Order 4th. The Edentata. Remarkable formations and economy
in the Sloths, Anteatus, Armadillos. Gigantic fossil species resem-
bling the Sloth.

Proceedings of the Royal Institution. 287

Order 5th. The Pachydermata. Beautiful and advantageous
structure of teeth in vegetable feeders. Living Elephants; their
formation and natural manners. Lost species, or Mammoth. Mas-
todons, Rhinoceros, Hippopotamus, all former inhabitants of Europe.
Newly discovered living Tapir. The Stag genus. The Horse.

Lecture IV. Wednesday, May 19.

Order 5th. The Cattle, or Ruminantia. Rumination; other kind
provisions in their favour. Wild and domesticated species of Cattle.
Camels. Deer. Antelopes. Giraffe. The Sheep, Goat, and Ox
genera. Gigantic fossil species of Deer and Ox.

Order 6th. The Cetacea orWhale tribes ; their structure, natural
manners, and relation to the rest of the Class. Conclusion of the

Course.

SyLLaBus oF A Course oF Lectures on Music. Br
Dr. CrotcnH.
Lecture I. Friday, May 7.

Remarks on the National Music of various Countries—Definition.
National Music supposed to be derived from the Music of the An-
cients. On traditional Accuracy. Remains of the Music of the
Greeks. Jewish Chants. The National Music of Ireland.

Lecture II. Friday, May 14.

The National Music of Scotland—Highland and Lowland. The
National Music of Wales,

Lecture III. Friday, May 21.

National Music supposed to be English s—that of France, Italy,
Switzerland, Germany, Spain and Portugal, Hungary, Poland, Scan-
dinavia and Norway, Denmark, Russia, Sclavonia, Turkey, Arabia,
Persia, the East Indies, China, Java, Otaheite, Canada, and Norfolk
Sound,

Lecture LV, Friday, May 28,

Superiority of Vocal over Instrumental Music. Remarks on Mo-
zart’s Comic Opera of Cosi fan tutte.
X 2

288 Proceedings of the Royal Institution.

Lecture V. Friday, June 4,

On the Progress of Improvement in the Opera. Remarks on Cosi
fan Tutte continued.

Lecture VI. Friday, June 11.

Remarks on the Opera of Cosi fan tutte concluded. Character of
Mozart.

Prospectus or Mr. Branpe’s LecturEs ON VEGETABLE
CHEMISTRY.

Lecture J. Saturday, May 8.

Objects of this department of Chemical Science—Of the structure
and growth of Seeds—Influence of air and water upon Vegetation—
Of heat and light—Structure of the root, trunk, branches and leaves—
peculiar functions of the latter—Their influence upon the constitution
of the Atmosphere. Growth of aquatic plants. Relative effects of
different plants upon the soil in which they vegetate. Of the sap of
plants and the theories of its circulation.

Lecture II. Saturday, May 15.

Methods of Chemical Analysis applicable to organic products—
Destructive distillation—Methods of purifying the vinegar furnished
by this process.—Production of coal gas.—Ultimate composition of
several vegetable substances—How far consistent with the theory of
Proportionals?—Use of chlorine in these analyses. Means of dis-
covering the immediate or proximate principles of vegetables by the
action of solvents and tests—Properties of starch—gluten—gum—
sugar. Mutual conversions of these substances into each other—

Relative nutritive powers of different vegetable subsiances used in
food.

Lecture IIT. Saturday, May 23.

Chemical history of the proximate principles of vegetables con-
tinued—Of the different kinds cf oil—Economy of oil gas illumination.
Manufacture of soap—Volatile oils—resins—-guaiacum—gum-resins
—balsams—Of the astringent principle in vegetables, and its appli-

=

Proceedings of the Royal Institution. 289

cations in the art of Tanning—Compositions of writing and printing
ink—Of the colouring matter of vegetables—Of colour-making—
Dyeing—Methods of conferring permanence upon vegetable colours
—Outline of the art of calico-printing—Of the newly discovered sali-
fiable bases—Cinchonia—Quinia—Morphia, &c,

Lecture IV. Saturday, May 29.

Of the theory of Fermentation and the production of beer and wine
—Components of wort and of must.—Change of sugar, mucilage and
starch into alcohol—Conversion of beer and wine into vinegar—
Properties of acetic acid—Of the different quantities of alcohol con-
tained in various fermented liquors, and of the state in which it exists
in them—Of the properties and composition of pure alcohol— Action
of acids upon alcohol— Preparation, properties, and composition of
sulphuric ether—General views connected with this department of
Chemistry—Conclusion of the Course.

On Saturday the 1st of May, the General Annual Meeting for the
election of a President, and the other Officers, was held at the House
of the Institution, when

The Right Hon. Ear Spencer, K.G. F.R.S. F.AS., &c., was elected
President.

Treasurer, Sir Scrope Bernard Morland, Bart,, M.P. LL.D.
Secretary, John Guillemard, Esq., F.R.S.

MANAGERS.

Baker, Sir Frederick, Bart., F.R.S.

Chamier, John, Esq.

Daniell, Edmund Robert, Esq.

Davy, Sir H. Bart., LL.D. P.R.S. V.P.

Duckett, Sir George, Bart., F.R.S. and F.S.A. V.P.
Hallam, Henry, Esq.

Hatchett, Charles, Esq., F.R.S. and F.S.A. V.P.
Lansdowne, Marquis of, LL.D. and F.R.S. V.P.
Moore, Daniel, Esq:, F.R.S. F.S.A, and F.L.S. VP.

290 Proceedings of the Royal Institution

Russell, Jesse Watts, Esq., M.P. F.R.S.

Scott, Sir Claude, Bart., F.L.S, and F.H.S. V.P.
Snodgrass, Thomas, Esq. F.R.S. V.P.

Soane, John, Esq., F.R.S. and F,S.A.

Somerset, Duke of, F.R.S. V.P.

Staunton, Sir George Thomas, Bart., M.P. F.R.S.

VISITERS.
Ansley, Col. Benjamin, F.H.S.
Antrobus, Sir Edmund, Bart., F.R.S., and .S,A.
Bostock, John. M.D, F.R.S, and F.L.S,
Chichester, Earl of, F.R.S.
Children, John George, F.R.S. and F.LS.
Daniell, John Frederic, Esq., F.R.S.
Fuller, John, Esq.
Leake, Lieut.-Col. W.M. F.R.S.
Leigh, James Heath, Esq.
Robinson, Rey. Sir John, Bart.
Solly, Richard Horsman, Esq., F.R.S. and F.S.A,
Sotheby, William, Esq., F.R.S. and F.S.A.
Stanley, Sir John Thomas, Bart., F.R.S. and F.S,A.
Taylor, George Watson, Esq., M.P.
Weyland, John, Jun. Esq., F.R.S.

At this meeting the Professor of Chemistry made a report of the
Proceedings in the Laboratory of the Royal Institution, in which he
enumerated the various investigations that had been carried on there,
and took a general view of the progress of Chemical Philosophy dur-
ing the preceding year. He then adverted particularly to the new
features that had been given to the Science by the discoveries of Sir
H. Davy, and to the high reputation which the Royal Institution had
thence derived; he trusted that it still contributed more towards the
promotion and extension of chemical Science than any similar esta-
blishment, similarly endowed, and that its real and permanent objects
were preserved and promoted, more especially in the extended course
of practical lectures delivered in the Laboratory ; in which, he observed,
an attempt is made to set forth with due diligence and dignity those
new principles in chemical philosophy which have exclusively ema-
nated from this establishment, to point out their originality and im-

Proceedings of the Royal Institution. 291

portance, and to preserve unsullied by jealousy, and unbiassed by pre-
judice, 2 School of Chemistry, which itis hoped may not be altogether
unworthy the name of its founder.

The following are the Terms of Admission into the Royal Institution.

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the amount of ONe Hunprep Pounps, or upwards, shall be Patrons for

292 Proceedings of the Royal Institution.

Life of the Library and Mineralogical Collection, Mechanical Collection,
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General or other Meetings of the Members.

The Annual Report of the Visitors of the Royal Institution of Great
Britain.
Albemarle-street, 12th April, 1824.

In presenting the usual Abstract of Accounts for the year 1823,
the Visiters of the Royal Institution are happy to have it in their
power to announce to the members the commencement of a new era.

It will be recollected that, in their last report, they felt it to be
their duty strongly to represent the propriety of inquiring into the
state and prospects of the establishment, and the paramount ne-
cessity of equalizing the income and expenditure, both by judicious
retrenchment and an appeal to the liberality of the members. The
managers did not hesitate immediately to adopt the suggestion
which was thrown out, of summoning a general meeting, by whom
a committee was appointed, who, with much labour and persever-
ance, went through the necessary investigation, and drew up a
plan to meet the exigencies of the case. The report of this com-
mittee has been already sent to the members, and: it is only neces-

Proceedings of the Royal Institution. 293

sary to remark that most of the suggestions contained in it have
been carried into effect by the Board of Managers.

By the liberality of the president and a few members (to one of
whom most particularly the Institution is indebted for the sugges-
tion, and a munificent contribution towards carrying it into effect) a
loan, without interest, has been raised, to pay off all the outstanding
demands ; so that the ruinous expedient of borrowing money at an
interest of five per cent. to meet the current expenses, will no longer
be deemed necessary.

The laboratory has been placed upon a new foundation, and the
expense of its maintenance has been withdrawn from the general
fund. It will in future depend for its support upon the liberality
of the old members, and an additional contribution from the new.
There can be no doubt that these means will be amply sufficient
to the end in view; for when it is considered that the question
to be determined is, whether or not the Royal Institution shall
maintain the high consideration it enjoys by means of original in-
vestigation and experiment, which of the members will refuse his
contribution ? One guinea per annum from each member, it has
been calculated, will be sufficient to maintain the laboratory in its
present state of efficiency, and for this small sum the privilege of
personally introducing one person to all the public lectures has
been conferred. The list of donations and contributions to the
laboratory fund, which accompanies this report, will prove that
the subscription has been begun with alacrity and spirit.

The admission fees and compositions of members will no longer
be considered, as heretofore, in the light of annual income, but
will be immediately vested in public securities; and, after paying
off the loan, will be carried to the account of the permanent fund,
which some years ago was so liberally begun by one of the mem-
bers.

With regard to the expenditure of the last year it may be ne-
cessary to make one remark as, without some explanation, the
total may be deemed excessive. Amongst the items is included
a sum of 6001. which was paid to the city of London, as a fine for
the renewal of the lease of the premises. By their under-leases

294 Proceedings of the Royal Institution.

the whole of this amount, and 10/. in addition, should have been
received from the tenants of the Institution, but only 3701, has
actually been recovered, one of the tenants being unable to fulfil
his covenant, whereby his right of renewal has become forfeited,
and \is now vested in; the Institution; the balance of 240/. may
therefore be considered as a sum of money laid out to great ad-
vantage.

It is not the duty of the visiters to anticipate the accounts of
the current year ; but, having taken some pains to ascertain the
scale of the present expenditure, they cannot resist the gratifica-
tion of communicating the result of their inquiries, which has been
highly satisfactory.

The estimated diminution of expense (excluding the 600/. fine)
is about 600/., to which must be added 3004. for the charge of the
laboratory, making a reduction of 900/. in the charge upon the
general funds.

The privilege of introducing one person to the Jectures, which
has been given to the members who have subscribed to the labora-
tory fund, has been found not to interfere with the number of an-
nual subscribers, which is, on the contrary, larger than in the pre-
ceding years; and the visiters have had the gratification to find
that the lectures in all cases have been well attended, and that the
theatre on some occasions has been full.

Under all these favourable circumstances, the visiters cannot
refrain from congratulating the members upon the new aspect
which the affairs of the Royal Institution haye assumed. They do
not hesitate to give it as their opinion, that the whole establish-
ment is now placed upon a much securer foundation than that o¢
any former period ; and if they feel any anxiety, it is that the mem-
bers, by their patronage of the laboratory fund, may not only enable
that department to persevere in those exertions, from which such
great benefits have already been derived to science, and such
honour to the nation, but may increase its efficiency, and enlarge
the sphere of its utility.

WINCHILSEA, BENJAMIN ANSLEY,
Joun FuLLeER, Joun Rozpinson,
Re Souty, J. F. Danizcu.

"' ares

295

Arr. XII. ASTRONOMICAL AND NAUTICAL
COLLECTIONS. No. XVIII.

i. Extracts relating to the Theory of the T1pxs.

[It is thought advisable to insert, in this article, a popular view
of the principal phenomena of the tides, which appeared some years
ago, ina periodical work of a miscellaneous nature, and to add to
it some few corrections, and some extensions, which form a part of
a more scientific investigation, that has lately been published in
the Supplement of the Encyclopedia Britannica.)

“ Of the objections,” says a writer in the Quarterly Review tor
October, 1811, p. 76, [which have been hastily advanced by some
authors, against the established theory of the tides,] “ the most
material seems to be, that according to the Newtonian opinion,
the moon must be supposed to repel the waters on the remoter
side of the earth, instead of attracting them. ‘The next is, that the
lunar action must be sufficient to overcome the forces of gravity and
cohesion. The third, that the time of high water is frequently
three, and sometimes six hours later, than that of the moon’s pas-
sage over the meridian.

“The difficulty in conceiving the apparent repulsion of the
waters on the remoter side of the earth, which very naturally occurs
to one who is but little conversant with the subject, appears to de-
pend on a want of sufficient attention to the manner in which the
mean solar and lunar attractions are counterbalanced. We are
unconsciously disposed to consider the earth, especially in com-
parison with the moon, as a body perfectly at rest, or at most as
an immense sphere poised on its axis, or having some secret sup-
port connected with its centre. And it is true that, if the earth
were suspended as an apple hangs on a stalk, or a terrestrial globe
on the pins which connect it with the brazen meridian, the attrac-
tive force of a distant body would necessarily tend to collect a
fluid surrounding it, about the part nearest to the disturbing body.

296 Astronomical and Nautical Collections.

But in fact the force counteracting the solar and lunar attraction
is by no means to be confounded with the operation of a support of
any kind, attached to the solid parts of the sphere alone; for the
force actually concerned in this case is equally efficacious with
respect to the fluid parts; and, acting exactly alike on every par-
ticle of the earth and sea, it precisely counterbalances the mean
force of attraction, and leaves only the difference of the attractive
powers, which are different for the different parts of the earth and
sea, to exhibit its effects in disturbing the relative situations of
those parts. This counterbalancing power is well known under the
name of the centrifugal force, being derived from the velocity of
the earth, either in its annual revolution round the sun, or, in the
case of the moon, from its velocity in revolving round the common
centre of inertia of the earth and moon. Since the earth actually
falls at every instant as much within the tangent of its annual orbit,
or the temporary line of direction of its motion, as it would de-
scend towards the sun in an equal time, if it were otherwise at
rest, this change of relation of the revolving body, which prevents
its actual approach to the centre of attraction, and counteracts the
force of gravitation, is, not improperly, considered as constituting
a distinct force, and is characterized by the term centrifugal. Be-
fore the introduction of the Newtonian theory, an attempt was
made, by the celebrated Dr. Wallis, to deduce the tides from a
difference of the centrifugal forces affectiug the opposite parts of
the earth and sea, in revolving round the sun, and round the com-
mon centre of gravity of the earth and moon; and Mr. Ferguson,
in later times, has endeavoured to explain an opinion of a similar
nature, by means of the whirling table; but the apparatus of Fer-
guson was so constructed, as to produce a greater velocity of rota-
tion in the remoter than in the nearer parts of the revolving system
of bodies, which is a difference that does not exist in the case to
be investigated; for the velocity of the different parts of the earth
and sea, with respect to their common annual revolution round the
sun, is precisely the same, the diurnal rotation being altogether in-
dependent of this revolution, and producing modifications of force,
which have their separate compensations, as distinctly indeed as

Astronomical and Nautical Collections. 297

the monthly revolution of the moon, which does not affect the
velocity of its mean annual revolution round the sun, together with
the earth.

*< It is therefore so far from being true, that the inequality of the
centrifugal force, at different parts, gives rise to any part of the
phenomena of the tides, that, on the contrary, the perfect uniformity
of this force is the basis of the determination of the powers imme-
diately concerned in these phenomena. The Atlantic and the Pa-
cific oceans are subjected to a centrifugal force precisely equal to
that which affects the solid parts of the earth; but when the lumi-
nary is over the Atlantic, its attraction for that ocean is greater
than for the central part, and consequently greater than the centri-
fugal force, so that this differential attraction tends to elevate the
Atlantic ; at the same time that its attraction for the Pacific ocean is
less than the mean attraction, and less than the centrifugal force,
which therefore prevails over the attraction, and the differential
force tends to raise the Pacific ocean almost as much as it tends to
raise the Atlantic in the opposite direction.

“ There is also an additional force, derived from the obliquity
of the action of the luminary on the parts of the earth not imme-
diately below it, which tends to compress the lateral parts, and to
increase the elevation at the ends of the diameter pointing to the
luminary.

“The readiest way of calculating the operation of all these
forces is, to reduce them to ahorizontal direction, and to determine
what inclination of each part of the surface of the sea, considered
as an inclined plane, will cause such a tendency, in a particle
situated on it, to move in acontrary direction, as precisely to coun-
terbalance, not only these forces, but also the new disturbing force,
derived from the attraction of the parts thus elevated ; and it may
easily be shown, that all these conditions will be fulfilled, if we at-
tribute to the surface of the sea the form of an oblong elliptic sphe-
roid, differing but little from a sphere.”

Now, “ we have only to recollect, with respect to the first ob-
jection” already mentioned, ‘“ that we are by no means required
to imagine that the moon repels the remoter parts of the earth and

298 Astronomical and Nautical Collections.

sea; but merely to understand, that these parts are left a little
behind, while the central parts fall more within the tangent, to-
wards the moon, and the nearer parts still more than the central
parts: nor is this a faet of which our belief must rest on any ob-
served phenomena of the tides, since it is completely demonstrable
from the general laws of gravitation and of central forces: so that
if no such tides were under any circumstances observable, their
non-existence would afford an unanswerable argument against the
universality and accuracy of these laws, as they are inferred from
other phenomena.

‘* The second objection is already answered in the statement of
the mode of operation of the disturbing force. The action of this
force is only supposed to be sufficient to retain a particle of water
in equilibrium on a surface of which the inclination to the horizon
is scarcely perceptible, or to cause the whole gravitation of a
column four thousand miles in height, immediately under the lu-
minary, to be equal only to the gravitation of a column shorter by a
few inches or feet, in another part of the spheroid. The objectors
have confounded this very slight modification of the force of gravi-
tation, with its complete annihilation by a greater force: and with re-
spect to the force of cohesion, it is so little concerned in counteracting
any elevation of this kind, that to attempt to calculate the magnitude
of any resistance derived from it would be perfectly ridiculous.

“‘ The third objection is only so far more valid, as it is opposed
to the imperfect and superficial notions,” which some authors have
entertained, “ of the supposed operation of the forces concerned :”
as if the sea could instantly accommodate itself to the temporary
form which would afford an equilibrium. In fact, however, it is
just as likely to happen, in the open ocean, that the transit of the
luminary may coincide with the time of low water as with that of
high water; and in more limited seas and lakes, there is no hour
in the twenty-four at which high water may not naturally be ex-
pected to take place, according to the different breadth and depth
of the waters concerned; while, under other circumstances, it may
happen to be high water only once a day, or once a fortnight, or
there may be no tide at all, without any deviation from the strictest

Astronomical and Nautical Collections. 299

regularity in the operation of the causes concerned. Since the
subject has hitherto been considered as extremely intricate, and has
not indeed yet been freed from all its embarrassments, we shall
here endeavour to explain the principles on which the investigation
has been conducted.

** The attempts that were made by Newton, to compute the
effects of the solar and lunar attraction on the sea, went no further
than to the determination of the magnitude of the elevation which
would at any given time afford a temporary equilibrium: and even
Maclaurin was satisfied with having ascertained the precise nature
of the form which the waters must assume in such a case. But it
is obvious that these determinations are by no means sufficient for
ascertaining the motions which arise from the change of relative
situation induced by the earth’s rotation, since the form, thus ascer-
tained, only affords us a measure of the force by which the waters
are urged, when they do not accord with it, and by no means ena-
bles us to say, without further calculation, how nearly they will at
any time approach to it. In fact, the change of the conditions of
equilibrium determines only the magnitude of this force, such as it
would be if the sea remained at rest, while it is in reality materially
modified, at any given time, by the effect of the motions which have
previously taken place: and supposing its true magnitude to be
ascertained, its immediate operation will at all times be complicated
with the conditions, under which an impulse of any kind is capable
of being communicated to the neighbouring parts of the sea, which
depend on the depth of the sea, as well as on the form of the earth.

“‘ Mr. Laplace has undertaken the investigation of the theory of
the tides, with all these additional complications ; and he considers
it as constituting, without exception, the most difficult depart-
ment of the whole science of astronomy; and yet this consummate
mathematician has omitted to include in his calculation the effects
to be attributed to resistances of various kinds, and to the irregu-
larities of the form of the sea, which appear to us to constitute by
far the more material difficulties in the inquiry. The general
problem, relating to the oscillation of a fluid completely covering a
sphere, and moving with little or no resistance, which Mr. Laplace

300 Astronomical and Nautical Collections.

has solved by a very intricate analysis, is capable of being exhi-
bited in a much less embarrassed, and, we apprehend, even in a
more accurate manner, by a mode of investigation, which is equally
applicable to the tides of narrow seas and of lakes, and which may
easily be made to afford a correct determination of the effects of
“resistance, as well as a ready mode of discovering the laws of mo-
tions governed by periodical forces of any kind; at least so far as
these forces are capable of being represented by any combina-
tions of the sines of arcs, which increase uniformly with the time.

“ The essential character of this method consists in comparing
the body actuated by the,given force to a pendulum, of which the
point of suspension is caused to vibrate regularly to a certain small
extent: the length of the pendulum being supposed to be such as
to afford vibrations of equal frequency with the spontaneous vibra-
tions of the moveable body, and the point of suspension to be car-
ried by a rod of such a length, as to. afford vibrations of equal fre-
quency with the periodical alternations of the force. It is then
shown, that such a pendulum may perform regular vibrations, con-
temporary with the alternations of the periodical force, and in-
versely proportional in their extent to the difference between the
length of the two rods: and that, whatever may have been the
initial state of the pendulum, the motion thus determined may be
considered as affording a mean place, about which it will at first
perform simple and regular oscillations; but that a very small re-
sistance will ultimately cause these to disappear:” so that the par-
ticular solution of the problem, which indicates a series of vibra
tions as they may be performed, is thus rendered general ; since
every other initial state of the vibrations must ultimately terminate
in this series.

“« Now the sea, or any of its portions, may be considered as bodies
susceptible of spontaneous vibrations, precisely similar to the small
vibrations of a pendulum ; and the semidiurnal variation of the form
which would afford an equilibrium, in consequence of the solar
and lunar attractions, is perfectly analogous to the regular vibration
attributed to the point of suspension of the pendulum. ‘The fre-
quency of the simple oscillations of the sea, or of any of its parts,

Astronomical and Nautical Collections. 301

supposing their depth and extentknown,” and their form sufficiently
simple, ‘‘ may easily be deduced from the important theorem of
Lagrange, by which the velocity of a wave of any kind,” when suffi-
ciently broad, “is shown to be equal to the velocity of aheavy body,
which has fallen through half the height of the fluid concerned :
but in the case of a tide extending to any considerable portion of
the surface of the globe, this velocity must be somewhat modified
according to the comparative density of the central and the super-
ficial parts.

‘“* The most remarkable consequence of this analogy is the law,
that if the simple oscillations, of which the moving body is suscep-
tible, be more frequent than the period of the recurring force, the
pendulum will follow its point of suspension with a direct motion; .
but if the spontaneous vibrations be the slower, the motions will be
inverted with respect to each other: and, with regard to the tides,
we may infer from this mode of calculation, that supposing the
earth to be between five and six times as dense as the sea, the
oscillations of an open ocean can only be direct, if its depth in the
neighbourhood of the equator be greater than fifteen or sixteen
miles: and that if the depth be smaller than this, the tides must
be inverted, the time of low water corresponding, in this case, to
the transit of the luminary over the meridian.

“‘ This distinction has not been explicitly made by Mr. Laplace,
although he has calculated, that for a certain depth, of a few miles
only, the tides of the open ocean must be inverted, and that for
greater depths they will be direct: but the intricacy of his formule
seems to render their use laborious, and perhaps liable to some in-
accuracy; and in the application of his theory, he seems to have
lost sight even of the possibility of an inverted tide. In narrower
seas, which Mr, Laplace has not considered, a smaller depth will
constitute the limit between these two species of tides; and in
either case the approach of the depth to this limit will be favour-
able to the magnitude of the tide.” It may also be remarked, that
if the depth of the sea became gradually smaller in receding from
the equator, till it vanished at the poles, its surface, as well as that
of the earth, having the form of an oblate spheroid, the time re-

Vou, XVII. ¥

302 Astronomical and Nautical Collections.

quired for a wave to trayel round it would be equal in all latitudes,
and the tides would be of the same species in every part; while
the tides of the atmosphere, on the other hand, independently of the
resistance, would be indirect at the equator, and direct near the
poles.

“* However the primitive oscillation may be constituted, it is easy
to understand, that it will be propagated through a limited channel,
connected with the main ocean, in a longer or shorter time, ac-
cording to the length and depth of the channel; and that if the
channel be open at both ends, the tide will arrive at any part within
it by two different paths ; and the effects of two successive tides
may in this manner be so combined as to alter very materially the
usual course of the phenomena: for instance, if there were about
six hours’ difference in the times occupied in the passage of the two
tides over their respeciiye paths, the time of the high water be-
longing to one tide would coincide with that of the low water
belonging to the other, and the whole variation of the height might
in this manner be destroyed, as Newton has long ago obseryed with
respect to the port of Batsha: and it may be either for a similar
reason, or from some other local peculiarity of situation, that no
considerable tides are observed in the West Indies; if indeed it is
true, that the tides are so much smaller there than might be ex-
pected from calculation ; for in fact the original tides of an open
sea, not exceeding a mile or two in depth, would amount to a few
inches only, even without allowing for the effects of resistance. In
the middle of a lake, or of a narrow sea, there can be little or no
primitive elevation or depression; and the time of high water on its
shores must always be about six hours before or after the passage
of the luminary over the middle ; so that from this source we may
derive an infinite diversity in the times at which these vicissitudes
occur in different parts.

“« The effects of resistances of yarious kinds, in modifying the
time of high water, cannot easily be determined in a direct and
positiye manner from immediate observation, Mr. Laplace ap-
pears to be of opinion that these resistances are wholly inconsider-
able ; but if any dependence can be placed on the calculations of

Astronomical and Nautical Collections. 303

Dubuat, we ought to expect a yery different result, since, accord-
ing to Dubuat’s formula, the resistance, in the case of a tide of any
moderate magnitude, must far exceed the moving power. From
this result, however, nothing can be concluded with certainty, ex-
cept that the formula is extremely defective with respect to great
depths and slow motions; yet we may infer from it, as a probable
conjecture, that the resistance must be great enough to produce
some perceptible effects, and even that it must be greater than
would be expected from another mode of calculation founded on
the same experiments, (PAil. Trans. 1808; Suppl. Enc. Br, Art-
Hyprautics,) which would give the proportion of the greatest re-
sistance to the greatest moving force only as 4 of the height of the
tide, increased by about ten feet, to the whole depth of the ocean
concerned, at least on the supposition of a uniform depth and a
smooth bottom, which indeed must be far from the truth; since
he inequalities of the bottom of the sea must tend very greatly to
increase the resistance, especially that part of it which varies as
the square of the velocity.

““ Now it has been demonstrated, (Nich. Journ. Illustr. Cel.
Mech. Suppl. E. Br. Art. Trpzs,) that a resistance, simply propor-
tional to the velocity, would not disturb the perfect regularity of
the oscillations concerned, and that it would only retard them when
direct, and accelerate them when inverted, by the time correspond-
ing” to a certain arc, of which the tangent is to the radius, as the
velocity due to half the length of the pendulum synchronous with
the periodical force is to the yelocity at which the resistance he.
comes equal to the force of gravity, and as the length of the pen-
dulum synchronous with the spontaneous oscillation to the dif-
ference of the lengths of these two pendulums conjointly. ‘ Nor
will the displacement produced by an equal mean resistance, vary-
ing as the square of the velocity, be materially different ; the body
or surface merely oscillating a little about its mean place, in con.
sequence of the different distribution of the resistance.

“ Here, then, we have another source of very great diversities in
the times of the tides, according to the dimensiuns of the seas con-
cerned, even in those parts in which the tides may be supposed to

x2

304 Astronomical and Nautical Collections.

be rather original than derivative, not excepting the most widely
extended oceans. There are, however, other considerations, which
limit, in some measure, the probable magnitude of a resistance
varying either accurately or very nearly in proportion to the square
of the velocity; and the chief of these is the time of high water at
the spring and neap tides, which must be very differently affected
by such a resistance, since it must necessarily cause a much greater
acceleration or retardation of the spring tides than of the neap
tides. Hitherto it has only been observed that, in particular ports,
the greatest tides have happened the earliest; but no accurate
comparison of the times of high and low water have been made in
a sufficient variety of circumstances to authorise our forming any
general conclusion of this kind. It might indeed be supposed, that
this diversity of the relative time of high water might be modified
and concealed by a difference of velocity in the progress of the
different tides from their source in the ocean to the places of ob-
servation, according to the different degrees of resistance opposed
to them: but, if we can depend on a mode of calculation which has
occurred to us, the velocity, with which a wave or tide is propa-
gated, is not materially affected by a resistance of any kind, its
magnitude only being gradually reduced, and even its form re-
maining little altered by this cause, when the resistance is nearly
proportional to the velocity ;” although, as the form of a wave is
evidently altered in approaching the shore, its summit advancing
more rapidly than its basis, till it falls over and the wave breaks,
so a tide remote from the ocean is generally observed to rise some-
what more rapidly than it falls.

** Another limitation of the magnitude of a resistance, varying as
the square of the velocity, is the modification of the apparent pro-
portion of the solar to the lunar force, which must arise from it
Tn assuming that the comparative magnitudes of the tides in the
open sea must be precisely the same with those of the disturbing
forces which occasion them, astronomers have hitherto neglected
two very material circumstances; one, the effect that a greater
approach of the frequency of the spontaneous oscillations, to the
solar or lunar period, must have in augmenting the respective tide ;

Astronomical and Nautical Collections. } 305

the other, the greater diminution of the spring than of the neap
tides by the operation of a resistance proportional to the square of
the velocity, which gives to the lunar tide a greater apparent pre-
ponderance. Mr. Laplace is obliged to have recourse to some
imaginary peculiarities in the local situation of the port of Brest,
in order to explain the existence of lunar and solar tides in the
proportion of three to one, while the other phenomena, depending
on the moon’s attraction, make it improbable that the lunar force
can be to the solar in a much greater ratio than that of five to two.
But, in fact, the proportions of the tides in other ports, very dif-
ferently situated, for instance at St. Helena, are nearly the same
with those which have been observed at Brest; and it\is demon-
strable, that such a diminution of the apparent. solar force must
necessarily be the consequence of the operation of any resistance,
proportional to the square of the velocity; besides being in part
dependent, according to the most probable suppositions, upon the
actual depth of the sea, as being more favourable to the exhibition
of a lunar than a solar tide.

“« There remains to be explained the interval which elapses be~
tween the time of new or full moon, and the occurrence of the
highest tides, amounting at Brest to about a day and a half, and at
London bridge probably to two days. The most simple supposi-
tion respecting this interval, is that which Mr. Laplace has adopted ;
as the retardation is greater at London bridge than at Brest, so it
may be imagined that there are other places, still more exposed
than Brest to the great oceans, at which it will altogether disap-
pear. We cannot, however, discover any thing like a progressive
succession of this kind in the tides which are observed at different
parts of the continent ; nor would so great a time as a day and a
half be required for the passage of a tide over more than half the
circumference of the globe, upon any probable estimate of the depth
of the sea.” The full development of the manner, in which the
resistance may be supposed to cause this retardation, will be found
in the Supplement of the Encyclopedia.

“* We have assigned abundant reasons for the diversity which
occurs in the time of high water at any given period of the moon’s

306 Astronomical and Nautical Collections.

revolution in places differently situated ; and this time being once
ascertained for any one tide, we may easily infer by calculation
the time at which every other tide will occur; and we shall find in
this sequence the most perfect coincidence between theory and ob-
servation. Thus, if the high water of the spring tides, derived
from the coincidence of the solar and lunar high waters, soon after
the new or full moon, happened at any port precisely at noon, the
next time of the high water belonging to the solar tide would of
course be at midnight, and that of the lunar high water twenty-five
minutes later; and the true time of high water will divide this in-

erval neatly in proportion to the apparent forces, and will occur
about eighteen minutes after midnight,” [the interval being 12
18™, and not 1248, as it has been hastily assumed for the table of
the Supplement :] “ and the next day it will be high water about
thirty six minutes after twelve. This retardation will increase
from day to day, since its mean daily value is about fifty minutes ;
and at the neap tides following the moon’s quadratures, it will be-
come about twice as great as at the syzygies, its different values, in
these cases, being nearly proportional to the magnitude of the spring
and neap tides; so that Bernoulli has considered them as affording
the most correct estimate of the comparative magnitude of the solar
and lunar forces; although they are probably less capable of being
accurately determined by direct observation than the different ele-
vations and depressions. We can scarcely imagine it possible that
any individual, acquainted with these simple facts alone, to-say
nothing of many others, equally well established, could for a mo-
ment entertain the slightest doubt of the real and immediate de-
pendence of the tides on a combination of the solar and lunar
attractions.”

“In the diurnal and annual variations of the height of the tides,
there is no peculiar difficulty. The declinations and distances of
the luminaries modify their forces in a manner which is easily de-
termined ; and the periods of these changes being much greater
than the times of spontaneous oscillation in any of the seas con-
cerned, the effects directly follow their causes, almost in the simple
proportion of the intensity of the forces concerned. Mr. Laplace

ea

tie eo

‘ Astronomical and Nautical Collections. 307

has calculated, that in an ocean of équable depth, the difference
between the heights of the morning and evening tides, depending
on the declination of the luminary, must wholly disappear ; but
we cannot help suspecting that there must be an imperfection in
some of the many steps of his investigation. The depth would be
equable if the whole sphere were fluid; and it will not be denied
that in this case there would be a difference in the morning and
evening tides, very nearly coinciding with that of the primitive
variations of the figure affording an equilibrium: nor can we dis-
cover any imperfection in the method, which Mr. Laplace himself
has sometimes adopted, of considering the difference of the two
tides as a separate diurnal tide, and determining its magnitude pre-
cisely in the same manner as if it existed alone.”

“When a regular tide moves continually forwards in an open
ocean, the progressive motion of the fluid is the greatest, or in other
words, the flood is the strongest where the elevation is greatest, and
the motion is retrograde, constituting the ebb, wherever there is a
depression. In a river, the effect of a stream would only so far
modify the velocity, as to make it proportional to the elevation
above or the depression below a different level; but if a river or
channel of any kind terminated abruptly, so as to cause a reflec-
tion, the progressive velocity would commence from the time of low
water, and continue till that of high water only, or even be coun-
teracted by the motion of the current, so as to cease still earlier,
and to commence later. The rivers, in which our tides are com-
tionly observed, seem to hold a middle place between these two
¢asés : at Lambeth, for instance, the flow of the tide is continued,
not during the whole time that the watet remains elevated above a
cettain level, but about three quarters of an hour after the time of
high water, at which it would cease near the end of a channel ter-
minating abruptly. And it is probable that by similar considera-
tions the course of the ebb and flood tides might be explained in
many other cases.”

“If we apply the same mode of calculation to the tides of the
atmosphere, they will appear to be subject to some very singular
modifications, At the poles they must be very small; at the equa

308 Astronomical and Nautical Collections.

tor moderate; but at the latitude of about 42°, where the rotatory
velocity of the earth’s surface is equal to the velocity with which
any impression is transmitted by the atmosphere, or at about 40°
of the lunar tide, the height of the oscillations will only be limited
by the resistances, the greatest elevation occurring about three hours
after the transit of the luminary; nearer the pole they will occur ear-
lier than this, and nearer the equator a little later.” Possibly, in-
deed, the slight obliquity in the direction of the high water might
have some little tendency to equalize the height of the tides of dif-
ferent parts of the atmosphere : ‘‘ it seems, however, to be a mis-
take to suppose, that the effects of the atmospherical tides must be
more perceptible near the equator than in temperate climates; and
the variations of the barometer, which have been observed between
the tropics, are manifestly independent of the lunar attraction, oc-
curring regularly at certain hours of the day or night; as indeed —
the tides of the ocean might have been expected to occur, if they had
really been derived from the” meteorological causes to which some
authors have ‘ chosen to attribute them.”

Of the article Trpxs in the Supplement, the first. section relates
to the ‘‘ Progress of contemporary tides as inferred from the times
of high water in different ports.” The author’s conclusions from a
tabular comparison of observations are these :—

“ First, that the line of contemporary tides is seldom in the ex-
act direction of the meridian, as it is supposed to be universally in
the theory of Newton and of Laplace ; except, perhaps, the line of
the twenty first hour [of Greenwich time] in the Indian ocean,
which appears to extend from Socotora to the Almirantes, and the
Isle of Bourbon, lying nearly in the same longitude.

‘« Secondly, that the southern extremity of the line advances as it
passes the Cape of Good Hope, so that it turns up towards the
Atlantic, which it enters obliquely, so as to arrive, nearly at the
same moment, at the Island of Ascension, and at the Island of
Martin Vaz, or of the Trinity.

“Thirdly, after several irregularities about the Cape Verd Islands,
and in the West Indies, the line appears to run nearly east and
west from St. Domingo to Cape Blanco, the tides proceeding due

_ Astronomical and Nautical Collections. 309

northwards ; and then, turning still more to the right, the line seems
to become N.W. and §.E. till at last the tide runs almost due east,
_up the British Channel, [while another part of it passes] round the
north of Scotland into the Northern Ocean, sending off a branch
down the North Sea to meet the succeeding tide at the mouth of
the Thames.

“ Fourthly, towards Cape Horn again there is a good deal of
irregularity; the hour-lines are much compressed between South
Georgia and Terra del Fuego, perhaps on account of the shallower
water about the Falkland Islands and South Shetland.

Tn the fifth place, at the entrance of the Pacific Ocean, the
tides seem to advance very rapidly to New Zealand and Easter
Island; but here it appears to be uncertain whether the line of
contemporary tides should be drawn nearly north and south
from the Gallapagos to Terra del Fuego, or N.E. and S.W. from
Easter Island to New Zealand; or whether both these partial di-
rections are correct: but on each side of this line there are great
irregularities, and many more observations are wanting before the
progress of the tide can be traced, with any tolerable accuracy,
among the multitudinous islands of the Pacific Ocean, where it
might have been hoped that the phenomena would haye been
observed in their greatest simplicity, and in their most genuine form.

'“ Lastly, of the Indian Ocean the northern parts exhibit great
irregularities, and among the rest they afford the singular pheno-
menon observed by Halley in the port of Tonkin, and explained by
Newton in the Principia: the southern parts are only remarkable
for having the hour lines of contemporary tides considerably
crowded between New Holland and the Cape of Good Hope, as if
the seas of those parts were shallower than elsewhere.”

The second section relates to the “ disturbing forces that occa-
sion the tides,” and presents nothing that is not readily demon-
strable, and indeed universally admitted, except, perhaps, the
magnitude of the primitive elevation, produced by the lunar and
solar forces, which is made two feet and ten inches respectively, or
at the very utmost 2} feet and eleven inches, for the actual density
of the earth and sea, instead of the much greater height commonly

310 Astronomical and Nautical Collections.

assigned to it, on the very erroneous supposition of a homogeneotis
sphere of water.

The third section investigates the ‘ effects of resistance in vi-
bratory motions, whether simple or compound,” and reduces into
a somewhat more technical or fashionable form the propcsitions
which the author had before deduced from a geometrical mode of
representation, but with considerable extensions and improve-
ments: and as a corollary tending to illustrate the accuracy of bis
formulz, he has applied them to the problem of a pendulum mov-
ing with a resistance proportional to the velocity, which had been
left incomplete by Euler. He has shown that the resistance, in
Captain Kater’s experiments, could only have caused an error of a
second in about fifty years: a quantity certainly altogether insig-
nificant, but which could not with propriety be wholly neglected,
while it was known that its magnitude was determinable; and
while its insignificance remained undemonstrated.

He then proceeds to compute the effect of periodical forces with
or without resistance, and shows that the effects of such forces on a
pendulous or vibratory body are always most considerable when
the period of the force approaches very near to that of the vibra-
tion: a proposition which is illustrated by the sympathetic vibra-
tions of the pendulums of clocks, and in the motion of the inverted
pendulum, invented by Mr. Hardy, as a test of the steadiness of a
support, which shows, when it is well adjusted to the rate of a
clock, that no pillar can be so steady as not to communicate to it
a very perceptible motion by its regular, though extremely minute,
and otherwise insensible change of place.

The theorem most immediately applicable to the case of the tides is this,
dds ds

(K): “ the equation, a +A 7 + Bs + Msin, Gt = 0, may be satisfied
by taking s = aavine gp Ms epicpay sin. (Gt = arcta — AG 2”
/ ([GG—BF + AAGG B-GG

which is also extended by a subsidiary approximation to the case of a resistance
varying as the square of the velocity.

Inthe fourth séction of the article we find the *« Astronomical deter-
mination of the periodical forces which act on the sea or on a lake,”
affording the equations which by means of Theorem K, could give

Astronomical and Nautical Collections. 311

at once the height of the tides in any port, if the coefficients were
sufficiently determined, and even without this determination affording

some interesting conclusions from facts that are already well known.

For a canal or a sea lying in an easterly and westerly direction, the periodi-
cal force is shown to vary as sin cos Alé, sin Az., and for a canal deviating
from that direction in a given angle, as sin cos Alt. sin (Az. + Dev.). And in
the two cases of a canal running east and west in any latitude, and of a canal
situated obliquely at or near the equator, the force becomes, still more simply,
first, L sin cos Decl. sin Hor, Z + 1’ cos* Decl. sincos Hor. /, i being the
sine of the Jatitude, and L’ its cosine; and secondly, if p be the sine of the
deviation, or of the angle formed by the length of the canal with the equator,
and D’ its cosine, D sin cos Decl. cos Hor. 7 + v’ cos? Decl. sin cos Hor. /

A series is then found for representing the declination by means of arcs in-
creasing uniformly with the time; but it is observed that for the purposes of
calculation it is sufficient to suppose the sun and moon to move uniformly
in the ecliptic, or even to have uniform motions in right ascension; whence
-we obtain for the sun’s force, on a canal running east and west, putting @ for
the sine of the obliquity of the ecliptic, © for the sun’s longitude, and ¢ forthe

horary angle, S(t @ [ 5 cos (¢- ©) — }cos (¢ + ©)] +1e” [} cos(t—3 ©)
—400s(¢+8@)J +1” [4cos(t—5 ©)—} cos ((+ 5 ©)] + 1 ( - 1%)
‘ 2 a

sin. 2 ¢ + a [isine(t+t@ +1sine(t-@)]: a’, @’, and e”, being

coefficients derived from , and equal respectively to about .3645, .0078, and
.00002, and a@? = 1585. From each of the terms, expressing the forces, the
value of the corresponding portion of the space described may be obtained by
means of the general Theorem K, substituting, in the case of the solar tide, for
the coefficient of the simple resistance A, the value 4’ = 4 + 2.88 DM’, in
which D is the coefficient of the resistance varying as the square of the velo-
city, and M’ the supposed actual extent of the lunar tide; and for the lunar
tide A” = A+ 2.88 DS’ + .3434 D(M’— S’).

But without calculating the precise amount of all the coefficients, the author
proceeds to demonstrate in general, that ‘‘ the results, with regard to the space
described, will not differ much from the proportion of the forces, except when
their periods approach nearly to that of the spontaneous oscillation, repre-
sented by B.” And “ considering in this simple point of view the correct
expression of the force ; we may observe that the phenomena, for each lumi-
nary, will be arranged in two principal divisions, the most considerable being
represented by } (1’, D’) cos* Decl. sin 2 Hor. Z, and giving a tide every
twelve hours, which varies in magnitude as the square of the cosine of the de-
clination varies, increasing and diminishing twice a year, being also propor-
tional to the cosine of the latitude of the place or of the inclination of the

312 Astronomical and Nautical Collections.

canal to the equator, and disappearing for a sea situated at the pole: the

econd part is a diurnal tide proportional to the sine of the latitude or of the
inclination, being greatest when the luminary is furthest from the equinox, and
vanishing when its declination vanishes.”

He next proceeds “ to inquire more particularly into the cause of the
hitherto unintelligible fact, that the maximum of the spring tides in the most
exposed situations, is at least half'a day, if not a whole day, later than the
maximum of the moving forces.

“ Now it is easy to perceive that, since the resistance observing the Junar
period is more considerable than that which affects the solar tide, the lunar
tide will be more retarded or accelerated than the solar; retarded when the
oscillation is direct, or when G? — B is [negative,] and accelerated when it is
inverted, or when that quantity is [positive] ; and that, in order to obtain the
perfect coincidence of the respective high waters, the moon must be further
from the meridian of the place than the sun; so that the greatest direct tides
ought to happen a little before the syzygies, and the greatest inverted tides a
little after ; and from this consideration, as well as from some others, it seems
probable that the primitive tides, which affect most of our harbours, are rather
inverted than direct.”

As aconvenient epoch for dating the beginning of a series of tides, it is ob-
served that the mean conjunction, at the beginning of 1824, happens exactly at
mean noon of Jan. 1, in the time of the island of Guernsey or of Dorchester,
and at 18™ 49s Parisian mean time.

It is further observed respecting the effects of resistance, that this cause ‘¢ tends
greatly to diminish the variation in the magnitude of the tides, dependent on
theirnear approach to the period of spontaneous oscillation, and the more as the
resistance is the more considerable ; and supposing, with Laplace, that in the
port of Brest, or elsewhere, the comparative magnitude of the tides is altered from
the proportion of 5 to 2, which is that of the forces, to the proportion of 3 to 13
the multipliers of the solar and lunar tides being to each other as 5 to 6,...
we find that B must be either .g380 or .6398, and the former value making the
lunar tide only inverse, we must suppose the latter nearer the truth; and the
magnitude of the tides will become 1.663 and 1.998, and . . 4 cannot be greater
than .632. It seems probable, however, that the primitive tides must be in a
somewhat greater ratio than this of 2 to 1,and 5 to 3, when compared with the
oscillations of the spheroid of equilibrium; and if wesuppose B=.g, and A still

= = we should have [6.364] and [8.78] for their magnitude ;” so that the

actual elevations would be about 6 and 19 feet respectively.

“« Now... the tangents of the angular measures of the displacement, 26 7

give us 69° 50’ and 72° 40’ for the angles themselves, when B = .6328 3 and

’

Astronomical and Nautical Collections. 313

if B =.9, these angles become 45° and 70° 94’ respectively ; the difference in
the latter case, 25° 24’, corresponding to a motion of more than 24 hours of the
moon in her orbit.

“ Tt appears then that, for ‘his simple reason only, if the supposed data
were correct, the highest spring tides ought to be a DAY LATER than the con-
junction and opposition of the luminaries ; so that this consideration obviously
requires to be combined with that of the effect of a resistance proportional to
the square of the velocity, which has already been shown to afford a more ge-
neral explanation of the same phenomenon,”

It may easily be admitted that this theory may require much further illus-
tration, and perhaps discussion, before it can be rendered very popular, or in-
telligible, in all its bearings; but in point of mathematical evidence, it may
not be superfluous to insert here the reduction of the expression of the force
acting on an oblique canal into the simple form which the author has adopted.
without a demonstration, at the end of his paper.

Since the force f = sin cos Alt. sin(Az. + Dev.) = sin cos Alé. (v’ sin Az.
+ pcos 4z.); and sin Alt. = ut sin Decl. + 1’ cos Decl. cos Hor. Z 3 also
cos Decl. sin Hor. 7

cos Ale.

Hor. 7 , and cos? Alt. sin? Az. = cos? Decl. sin? Hor. 7 =cos? Alt. (1— cos? Az.)
and cos? Alt. cos? Az. = cos? Alt. — cos* Decl. sin? Hor. Z = 1— sin? Alé.—
cos? Decl. sin? Hor. 7 ;, whence cos Alt. cos Az. = 1 — } (sin? Alt + cos?
Decl. sin? Hor, Z) + 3 (sin? Alt. + cos? Decl. sin? Hor. Z)? — yg-++5 and
finally,

f = (“sin Decl. + v' cos Decl. cos Hor. /)(v' cos Decl. sin Hor. Z + D
[1 — 4(sin? Alé. + cos? Decl. sin? Hor. Z) + 32....]) 3 which may readily
be more completely developed if required.

sin Az, = 3; we have cos Alt, sin Az. = cos Deel. sin

But for a lake obliquely situated at the equator, when L = 0, and L’ = 1,
the expression becomes sin Alt. = cos Decl. cos Hor. 7, and cos? Alt. cos?
Az. = 1 — cos? Decl. cos? Hor. Z — cos? Decl. sin? Hor. Z =1 — cos?
Decl. = sin? Decl., and cos Alt. cos Az. = sin Decl. ; whence
f = cos Decl. cos Hor. Z (d’ cos Decl. sin Hor, Z + pv sin Deel.) = p’ cos?
Decl. sin cos Hor. 7 + dD sin cos Decl. cos Hor. Z, which is the equation
given at the end of the Article, agreeing with the equation of the form for a
canal running east and west, in having for each luminary a semidiurnal tide
which is greatest when the declination vanishes, and a diurnal tide increasing,
onthe contrary, as the sine of twice the declination increases. 'The two for-
mule give the same result for a canal coinciding with a part of the equator,
and they appear in other cases to represent the force for every part of the same
oblique great circle, the deviation at the equator being equal to the latitude
when it becomes perpendicular to the meridian.

Lapuace, assisted by the indefatigable Bouvarp, has lately published a very
valuable continuation of his Researches on the Tides, as a XIIIth Book of his

314 Astronomical and Nautical Collections.

Mécanique Céleste, Febr. 1824. . He has computed the results of about 6000
observations made at Brest since the year 1806, and has feund them confirm
in general those which he had obtained from the more ancient observations.
There are also some new deductions, which may be made subservient te the
further illustration of the principles laid down in the Supplement of the Ency-
clopzdia.

“I have considered,” says Mr. Laplace, (P. 160,) ‘‘ the tide of which the
period is abont aday. By comparing the differences of two high and two low
waters, following each other, in a great number of solstitial syzygies, I have
determined the magnitude of this tide and the time of its maximum, for the
port of Brest. I have found its height very nearly one fifth of a metre, and
one tenth of a day for the time that it precedes the time of the maximum of
the semidiurnal tide. Though its magnitude is not one thirtieth of that of the
semidiurnal tide, yet the generating forces of both these tides are nearly eqnal,
which shows how differently their magnitude is affected by accidental or ex-
traneous circumstances. This will appear the less surprising, when we con-
sider that if the surface of the earth were regular and entirely covered by the
sea, ‘the diurnal tide would disappear, provided that the depths were uniform
throughout.’ In fact, the observed heights of the diurnal and semidiurnal tides
are .2134™, and 5,6™ respectively, (P. 227); and the time that the diurnal tide
precedes the maximum of the evening semidiurnal tide is .095%, (P.226). It
is not quite clear that the words might not relate to the maximum resulting
from the most perfect combination of the solar and lunar diurnal tides ; but
we may suppose, for the sake of the calculation, that the high water of the
joint diurnal tide generally happens a little more than two hours earlier than
that of the semidiurnal tide.

B
W{(GG—BY + AAGG]
we assume the mean value of G, for the joint semidiurnal tide, about .98, and
for the diurnal.49, B being about .g, and 4=.1, the formula becomes=7.83, or
if A=.2, 4.4 for the semidiurnal, and 1.327 or 1.234 respectively for the diurnal,

Now supposing, for the determination of the multiplier,

and a or ces must be such that D sin 2 Decl. x 1.327 may be to D’ x 7.83
L
as .2134 to 5.6, or as 1 to 26.25; but sin 2 Decl. = sin 46° 55/.5 = .73045,
and we have p x .9691 : D’ x 7.83 = 1: 26.25 =D: D’ x 8.07andD ; D’
=1; eo 3.25 = cot 17° 6’, which must be the obliquity of the canal to
8.07
the equator if 4 = .1, or if A = .2, 10° 30’: either of which may possibly be
near the truth, though the obliquity of the main channel of the Atlantic to the
equator is probably greater. With respect to the times of high water, the
B AG

tangents —. = become, if A = .2, at 72°59’ and at s° 97’ respec-
s cs Gco-s ? { ; 7 9 7 pec-

i

Astronomical and Nautical Collections. , 316

tiyely ; the former expressing the acceleration of the inverted semidiurnal
tide, and the latter the retardation of the direct diurnal tide, by the effect of
friction, the sum of the former and twice the latter is 39° 53’, or very nearly a
right angle ; so that the interval, thus computed, instead of one tenth of a day
should be a little more than an eighth, It would, however, be necessary to com-
pare the height of the water at different intervals before and after high water,
in order to obtain the progressive magnitude of the diurnal tide with sufficient
accuracy to allow us to place any reliance on the result of this computation.
With respect to the disappearance of the diurnal tide in an ocean of equa-
ble depth, no doubt the depth must be equable in order that it may disappear,
but it must alse be evanescent. In fact, it is not conceivable in what other man-
ner the equability of depth can possibly produce such an effect ; for there is no
natural nor assignable relation between the period of revolution and that of
diurnal tide; the effects are just the same as if the earth were at rest, and the
attracting body moved round in a day, or in two days ; and it is impossible to
admit the accuracy of any refined method of investigation, from which Mr.

Laplace has obtained a result so clearly contradictory to the first principles of
mechanics.

ii. An easy Method of comparing the Time indicated by any Num-
ber of CHRonoMETERS with the given Time at a certain Station.
By the Rey, Fearon Fauttows, M.A., F.R.S., Astronomer at
the Cape of Good Hope.

Ler a transit instrument, or even a sextant with an artificial ho-
rizon, be established in a conspicuous situation on shore, where a
clock can always be regulated to true time: then provide a power-
ful Argand’s lamp with a shutter, so as to be able to darken the
lamp instantaneously; a few minutes before a certain hour in the
evening, notice being previously given to the ships, let the lamp be
lighted, and at the proper instant of time let it be darkened : this
may be repeated several times at short known intervals. Then the
errors of every chronometer on board of all the ships, from which
the lamp can be seen, are immediately found. After a certain
number of days, let the same be repeated, when the daily ship
rates will be given, since they are only the differences of these
errors divided by the number of-days elapsed between the two sets
of observations. It is evident that for greater truth these observa-
tions may be repeated at pleasure, No objection can be made from

316 Astronomical and Nautical Collections.

the chronometer being generally below deck, as one person might
have his eye upon it, and another immediately above him on the
upper deck might give a stamp with his foot the instant the lamp is
darkened.

The longitude of Cape Castle appears from eclipses of Jupiter’s
satellites to be about 18° 21’ E.
The height of Table Mountain above the sea was found,
Entrance from the narrow passage on the top (5 obs.) 3430 F.
Highest western point (13 obs.) .......... 3536
Highest eastern point (ll obs.) .......... 3545

ili. Easy APPROXIMATION ¢o the difference of LATITUDE on a
SPHEROID.

Supposine the excess of the equatorial semidiameter to be known
and equal to e, while the semiaxis is = 1, and having the linear
dimensions of a portion of a perpendicular to the meridian, we may
compute the difference of latitude and of longitude of its two ex-
tremities by considering the case of a sphere touching the surface
of the spheroid in the given parallel of latitude, and having the same
curvature with the perpendicular to the meridian at its origin,
which must therefore be extremely near to the points that require
to be compared with each other, so that they may be supposed to
be in the surface of this sphere.

Now the local semidiameter will always be 1 + ecos* L, Lbeing-
the true latitude, whence, by taking the fluxion, we obtain for the
tangent or the sine of the inclination of the surface, or the correc-
tion of the latitude, 2e sin cos L, consequently the sine of the cor-
rected or geocentric latitude will be sin L — 2e sin cos Leos L =
sin L(1 — 2e cos? LL). Hence we find, by trigonometry, the normal
to the equatorial plane (1 + e cos? L) sin L (1 — 2e cos* L).: sin L
= (1 + ecos? L) (1 — 2e cos? L) = 1 — ecos? L, e being a small
fraction ; and the normal to the axis, which is the radius of curva-
ture of the perpendicular circle at its origin, = (1 + e cos? L) cos
(L— 2e sin cos L) : cos L; but cos (L— 2e sincos L) = cos
L + 2esin cos L sin L = cos L (1 + 2e sin? L) and this normal

Astronomical and Nautical Collections. 317

becomes = (1 + e cos? L) (1 + 2e sin? L) = 1 +e +e sin? L,
But the radius of curvature of the meridian is equal to, the cube of
the former normal divided by the square of the semiparameter,
(Lyon’s Fluxions, P. 111,) or to (1 — 3e cos2 L) (1 + 2e) since

the semiparameter is a that is, tol + 2e — 3ecos?L, neglect-
e

ing the square of e as inconsiderable.

The angle at the pole on this tangent sphere will be the true dif-
ference of the longitude on the spheroid, and the true difference of
latitude may be found by reducing the angular difference of the leg
and hypotenuse into linear measure, and then again into an arc of
the curvature of the meridian; or more simply, by applying to the
arc a correction proportional to the difference of the radii of curva-
ture 1 +e + esin?L, and 1 + 2e — 3e cos?L, which is e—e sin? L
— 3e cos? L = 2ecos?L, which is the excess of the radius of the
perpendicular above that of the meridian, vanishing, as it ought to
do, at the pole, and becoming 2e at the equator.

If it be required to compute the effect of the deviation of the per-
pendicular to the meridian from the plane here supposed, it may
be found by making the actual verse sine of the portion of this
curve in question radius, and finding the tangent of the difference
of the curvature of the two circles here compared in an arc equal
to the difference of latitudes found, which will be to the whole an-
gular difference as 2e cos*L to 1. But since the verse sine in
question is only equal to the depression of the horizon at the given
distance, itis obvious that the tangent of so small an angle, with
this radius, may be neglected as inconsiderable.

iv. Extract of a Memoir on the Theory of Macnetism, read-at
the Academy of Sciences, 2 Feb. 1824. By Mr. Poisson.—Ann.
de Chimie, Feb.

Ir has been customary with many natural philosophers to ex-
plain the phenomena of electric attractions and repulsions by at-
tributing them to two distinct fluids, possessed of the property of
repelling the particles of the same nature, and of attracting, with an

Vor, XVII. Z

318 Astronomical and Nautical Collections.

equal force, particles of the opposite nature: and the law of this
force, as deduced from direct observation, is such, that it varies in
the inverse ratio of the squares of the distances, the same law that
governs the Newtonian attraction, which seems to prevail with re-
gard to all the actions of bodies that are sensible at great dis-
tances. Setting out from this hypothesis, they have determined,
by mathematical analysis, the distribution of the electricity at the
surface of conducting bodies, the electrical pressure which takes
place, from within to without, at every point of this surface, and
the action of the electric stratum which envelopes it on any given
point of space. The results of such calculations have been found
in perfect conformity with the numerous experiments made by
Coulomb on this subject about forty years ago, [as well as with the
still earlier experiments of the late Lord Stanhope, and of Mr.
Cavendish, and with the subsequent experiments of Professor
Robison, and others;] and at present this part of the science of
electricity, which relates to the equilibrium of the two fluids at
rest, abstracted from the proper action of the substance of the elec-
trified bodies, is theoretically complete ; or at least it presents us
only with such analytical difficulties, as depend on the form and
the number of bodies subjected to each other’s mutual influence.

From the analogy of the phenomena of magnetism with those of
electricity, it was natural to attribute also the attractions and re-
pulsions of magnetic substances to two imponderable fluids, a
boreal and an austral fluid ; and Coulomb inferred from his expe-
riments the same law of inverse proportion of the square of the
distances for magnetic as for electrical forces. The proofs, how-
ever, which he has adduced in support of this law, as far less con-
clusive for magnetism than for electricity, although there is still
reason to admit its truth, so far as it may be confirmed by the
agreement of calculations, rigorously derived from it, with actual
experiment.

Besides the analogy of the law of the forces, there is another
point of resemblance in the theories of magnetism and of electricity 5
that is, the distinction of bodies into two classes with regard to the
greater or less degree of permanence with which they retain any

eae ee

Astronomical and Nautical Collections. 319

given state of magnetic or electric properties which they have been
made to assume. With regard to electricity, the bodies called
conductors are instantly electrified by the influence of neighbouring
bodies already electrified, and when this influence is removed, they
no longer retain any trace of electricity. Nonconducting bodies,
on the contrary, are not sensibly electrified by this influence, ex-
cept when it is very powerful or very long continued ; but when
they have once been electrified by any other means, they preserve,
at each point, the electricity which has been once established in it,
retaining it by a peculiar power of the matter of which they are
composed. In this respect, such bodies, as are capable of mag-
netism, present us with a similar diversity; some of them, as soft
iron, for example, which has neither been twisted nor screwed, are
rendered magnetic by the influence of a neighbouring magnet ; and
when they are removed from it, they no longer exhibit any signs of
magnetism: others, such as hard steel, are very little susceptible
of this temporary influence ; but if magnetism has been once ex-
cited in them by more powerful means, they preserve this state of
magnetism, and, without doubt, by virtue of some particular
action which their particles exert on the boreal and austral
fluids.

Such are the principal analogies that are readily observed be-
tween electricity and magnetism ; but on the other hand, there ex-
ist between these two affections of bodies some essential differences
which must be mentioned, and which prevent the immediate ap-
plication of the theory of electricity to the phenomena of mag-
netism,

Electricity affects all bodies, whether as passing freely through
them, or as being attached to their particles: on the contrary, there
are only a small number of bodies, such*as iron in its different
states, steel, nickel, and cobalt, in which distinct traces of magnetic
action have been observed. Hence it has become a question, whe-
ther magnetism is a particular fluid, found only in bodies suceptible
of its influence, of if it is merely a modification of the electric fluid,
distributed in a particular manner. This question can scarcely be
decided in the present state of the science ; all that has hitherto been

Z2

320 Astronomical and Nautical Collections..

proved is, that magnetism may be developed in different bodies by
the action of electricity ; but the identity of the fluids is not neces-
sarily proved by the important facts, which have lately been dis-
covered, relating to their connexion. Happily the decision of the
question is not necessary for the purpose of this memoir, which is
independent of the intimate. nature of the boreal and austral fluids ;
its object being simply to determine the results of their attractions
and repulsions, and the laws of their distribution in magnetized
odies.

On this point the opinions of natural philosophers have not al-
ways been uniform. Before the time of Coulomb, the two fluids
were supposed to be tranferred, by the act of magnetizing a needle,
to its two ends, which thus became opposite poles; while in the
opinion of this illustrious experimenter, the boreal and austral
fluids are actually displaced in a very minute degree only, and do
not even quit the particles of the body to which they originally be-
longed before it was magnetized. This opinion, however singular
at first sight, has yet of late years generally prevailed: but the
theory depending on it could not be correctly developed without
an elaborate analysis, as will appear in the sequel of this me-
moir.

The general fact by which this opinion is supported, and which
indeed appears to establish its truth without any reasonable doubt,
is this: if we bring a magnet near to a piece of soft iron, the iron
will be magnetized by induction, and the two substances, when in
contact, will adhere to each other more or less strongly. The same
will happen to one or more pieces of iron brought near the first ;
they will also be magnetized by induction, and will adhere to the
first piece. If we then separate the different pieces, and remove
them from the magnet, we shall find that they have all returned to
their natural state, and that no portion of the magnetic fluid has
passed either from the magnet into the iron, or from one piece of
iron to another. “Now this is a marked difference between mag-
netism and electricity in conducting bodies; for the electric fluid
passes freely from one of these bodies to another when they are in
contact, or even when they are sufficiently near for the electric

Astronomical and Nautical Collections. 321

pressure to overcome the pressure of the air which confines the fluid
to the surface. This fact is universally true, and is independent of
the form or magnitude of the pieces of iron which are in contact,
and of the degree of their magnetism, or of the force of the magnet
which influences them: however intimate the contact may be, and
however long it may have lasted, the fluid never passes from any
one piece into another; whence it is natural to infer, that no sen-
sible quantity of magnetism is ever transported from one part to
another of the same piece of iron; and that the boreal and austral
fluids, contained by the metal in its natural state, undergo insensible
displacements only within it, when they are separated from one
another by any exterior action. This conclusion is also equally
applicable to those magnetized bodies, which retain the magnetism,
that has been excited in them, either by the continued influence of
a strong magnet, or by other means: the orly distinction between
these substances and soft iron is, that there exists in them a force
peculiar to each substance, known by the name of the coercive
force, of which the effect is, to arrest the particles of both fluids in
the situations which they occupy, and to oppose in this manner
first the separation of the two fluids, and then their return to their
natural union.

A question occurs, relating to this subject, which does not ap-
pear to have hitherto excited the attention of natural philosophers,
which arises however very naturally from considering the magnetic

- fluid as always belonging to the same constituent particles of the
magnetized bodies. It is not only not demonstrated that this fluid
is identical with the electric fluid, but it is not even necessary to
suppose that the phenomena of magnetism are produced in all
bodies by a fluid possessing every where the same intensity of at-
‘tractive or repulsive action, and therefore requiring to be consi-
dered as the same fluid in different substances. The identity of
the electric fluid is shown by its passing from one conducting body
into another, in such a manner as to preserve all its properties, and
to exercise, in the same circumstances, the same attractions or
repulsions ; but no such test as this can be applied in the case of
magnetism, and we cannot decide from mere reasoning, whether

322 Astronomical and Nautical Collections.

we ought to consider the magnetism of two different bodies, of pure
nickel and of soft iron, for example, as the same imponderable sub-
stance. It is therefore from experiment alone that we can learn
whether, neglecting the effect of the coercive force, which is very
small in both cases, the same exterior cause will produce the same
effect on the magnetic fluid contained in both these metals; or to
speak more precisely, whether similar and equal needles of iron
and of nickel, when submitted to the magnetic influence of the
earth, or of any other magnet, would make ia equal times an equal
or unequal number of oscillations. Mr. Gay Lussac has been so
good as to furnish me with an answer to this question, which he
has obtained by substituting, for the experiment here proposed,
another not less conclusive, which he considers as more capable of
an accurate result.

A magnetized needle, about eight inches in length, was made to
vibrate horizontally near the direction of the magnetic meridian ;
and by the action of the earth alone it made 10 oscillations in 131
seconds : a prismatic bar of soft iron of nearly the same length with
the needle, nearly 2 of an inch wide, and -4; of an inch thick ina
vertical direction, was fixed at the distance of two inches below the
needle, and in the plane of the magnetic meridian: the oscillations
of the needle were immediately accelerated, so that there were at
first 10 in 65 seconds, and soon afterwards 10 in 60 seconds ; but
they did not become more frequent afterwards. The bar of soft
iron was then exchanged for a similar and equal bar of pure nickel ;
and the needle made at first 10 oscillations in 78 seconds, and after
some time 10 in 77 seconds; and when the bar of nickel was re-
moved, the needle returned very nearly to its original state, making
10 oscillations only in 130 seconds, by the action of the earth alone.
The bars of iron and nickel did not exhibit any perceptible mag-
netism after the operations, so that the coercive force, if it existed
at all, must have been very weak in them: it might, however, be
concluded, that it was not absolutely wanting, because the bar
did not arrive immediately at the maximum of their action on the
needle; but this circumstance may also have depended on the action
of their magnetism on that of the needle, which required a certain

Astronomical and Nautical Collections. 323

interval for producing its greatest effect, on account of the coercive
force of the hard steel of which the needle was made, However
this may be, we must certainly conclude from the experiment, that
the mutual action of the magnetic fluids, contained in the steel and
the soft iron, is decidedly greater than the mutual action of the
fluids belonging to the steel and the nickel.

Perhaps it may be thought that this difference of the actions of
the magnetic fluid, in the different substances containing it, may
depend on the different quantity of the boreal and austral fluids
contained in each of these substances when they are in the neutral
state; the quantity being greater, for example, in iron than in nickel.
But this view of the subject is contrary to the phenomena, the quan-
tities of both fluids contained in each substance when neutral being
without limit, as far as regards our experiments : that is to say, the
forces which we command are never sufficient to exhaust or sepa-
rate them by the process of magnetizing ; for when a body is mag-
netized by the influence of a neighbouring magnet, it is admitted
that the intensity of its magnetic state, as shown by the effects
which it produces, increases without limit in proportion as we in-
crease the force of the magnet employed; which implies evidently
that we have not reached the limit of the decomposition or separa=
tion of the neutral fluid which it contains, in the same manner as
we find it impossible to separate completely the two electric fluids
contained in a conductor of electricity.

We must therefore necessarily suppose that the mutual action of
two magnetic particles, belonging to different bodies, depends on
the matter of each of these bodies. It is probable that this action
varies also with their temperature ; which seems, indeed, to follow
from an old observation of Mr. Canton, and from some more extensive
and more accurate experiments left unpublished by Coulomb, and
since inserted in the Traité de Physique of Mr. Biot. These expe-
riments show the influence of heat in the developement of mag-
netism; but having been made with magnetized bars, which were
by no means free from coercive force, the effects observed were de-
rived, without doubt, in part from the variation of their force, and in
part from that of the magnetic action. It would therefore be

324° ‘Astronomical and Nautical Collections.

important to repeat them with soft iron and with pure nickel at dif-
ferent temperatures, and even with other metals, which have not
hitherto been found to be subject to magnetical action: and,
in fact, the experiment of Mr. Gay Lussac, which has established
the difference of the action of the magnetic fluid in different sub-
stances, may afford some reason to suspect, that the intensity of
this action is only very weak at ordinary temperatures, though
perhaps not absolutely wanting, in cther metals.

After having explained the hypothesis, or rather the physical
foundations of the question which forms the subject of this memoir ;
we must endeavour to ascertain precisely in what manner we can
represent, from these principles, the disposition of the boreal and
austral fluids in magnetized bodies.

Let us first suppose that the substance is a cylindrical needle of
soft iron, of a very small diameter, and of any finite length; and
that, in the direction of its axis produced, there are one or more
centres of magnetic action. In the natural state of the needle the
two fluids contained in it are united in equal quantities throughout
its substance ; so that their actions being equal and opposite in all
distances, they destroy each other completely, and no sign of mag-
netism is exhibited. The effects of the centres of magnetic action
on the two fluids will separate them from each other; but each
boreal or austral particle will be very little removed from its pri-
mitive situation ; and in this new state the two fluids will succeed
each other alternately throughout the length of the needle, and this
length will consist of a series of very small parts, each of which
will contain, as in the neutral state, the two fluids in equal quan-
tities. Itis unnecessary to inquire whether the length of these
parts is equal to that of the constituent molecules of the iron; it is
sufficient for our calculations that their length should be very mi-
nute, so that it may.be neglected in comparison with the diameter
of the needle, and, in general, with the smallest dimensions of the
magnetized bodies which are to be considered. However small
this length may be supposed, it is still conceivable that it may be
different for the different substances which are capable of being
magnetized, as for iron and for nickel; but it will appear inthe

Astronomical and Nautical Collections. 325

sequel of this memoir, that this difference would not have any sen-
sible effect in the exterior magnetic action of the substances; so
that it would not serve to explain the difference of the actions
which they exert, in the same circumstances, on magnets placed in
their neighbourhood.

"If now we consider the case of a magnetized body of indetermi-
nate form and dimensions, we must attend te the lines or directionsin
which the separation of the two fluids takes place throughout its sub-
stance, and in which they are arranged alternately, as in the needle
which has been taken for an example. ‘These lines will in general
be curves depending on the form of the body, and on the external
forces which act on the two fluids: they may be termed lines of
magnetization, and we may call the minute parts, of which they are
composed, magnetic elements, each containing the boreal and
austral fluids in equal quantities. Thus, in each particular pro-
blem, we shall have to determine, for each point of the body to be
considered, the direction of the line of magnetization, [or polarity, ]
and the action of the magnetic element on any other point given in
position within or without the body. This action is the difference
of the forces exercised by the two fluids contained in the element,
arising from the slight separation of the boreal and austral mole-
cules in the state of polarity. It is somewhat surprising to see
that forces depending on distances so small, between the centres to
which they belong, should be capable of producing mechanical ef-
fects so manifest, as those which result from magnetic attractions
and repulsions ; but in fact the result of the action of all the mag-
netic elements of a magnetized body is a force equivalent to the
action of a very thin stratum covering the whole surface of the body,
and formed of the two fluids, the boreal and the austral, occupying
different parts of it. Now we are well acquainted, in the attractions
and repulsions of the conductors of electricity, with mechanical
effects, sometimes very powerful, which are produced by strata of
fluids of a thickness so inconsiderable as to escape our senses and all
our means of appreciating it. As to the ultimate magnitude of the
forces which we are thus required to attribute to cach of the two
separate portions.of fluid, whether boreal or austral, belonging to

326 Astronomical and Nautical Collections.

the same magnetic element, they must be incomparably greater
than the observed action of the element, and we can form no idea
of their magnitude from that of the magnetic attractions or repul-
sions which they occasion, since these effects are only derived from
their difference.

It is this distribution of the two magnetic fluids in magnetized
bodies, such as it has been here described, that is to be the subject
of the mathematical analysis contained in the sequel of this
memoir, ;

The first problem that was to be resolved was, to reduce to three
rectangular directions the results ofall the attractions and repulsions
of the magnetic elements of a magnetized body, of any imaginable
form, upon a point either within or without its surface. By adding
to these results, as belonging to any point within the body, those
of the external magnetic forces which act on the body, we shal!
have the whole forces which tend to separate the two fluids that are
united at the point in question, And if the matter of the body op-
poses no sensible resistance to the displacement of the fluids in
each magnetic element, or, in other words, if there is no coercive
force, it will be necessary, in order that there may be an equili-
brium, that all the attractions and repulsions should destroy each
other; since if any of them were uncompensated, they would pro-
duce a new decomposition of the neutral fluid, which is never ex-
hausted, and the magnetic state of the body would be changed.
The sum of the results is therefore made equal to zero with respect
to each of the three directions to which they are referred. The
equations of equilibrium thus formed will always be possible; they
will serve to determine, for each point of a magnetized body, the
three unknown quantities which they comprehend; that is, the in-
tensity of the action of a magnetic element on a given point, and
the two angles which determine the corresponding direction of the
line of polarity. At the extremities of each element these joint
results will not vanish, they will produce pressures, from within
each element, tending outwards, and counterbalanced by the
obstacle of which the nature is unknown, but which opposes the
passage of the fluid from one element to another. Whatever this

Astronomical and Nautical Collections. 327

obstacle may be, it is found in the superficial particles as well as in
the interior, so that there is no need of any external pressure, like
that of the air, to prevent the further removal of the fluid; and
this circumstance constitutes a material difference between the
state of induced magnetism and that of the induced electricity of a
conducting substance,

If the coercive force of the magnetized body required also to be
taken into consideration, it would then be sufficient for the magnetic
equilibrium that the result of all the exterior and interior forces
acting upon any point of the body should no where exceed the
given magnitude of the coercive force, the effect of which would be
similar to the friction of a machine. In this case the equilibrium
might take place in an infinity of different manners ; but among all
these possible states, there is one which is particularly remarkable,
and in which bodies are said to be saturated with magnetism: a
ease which may hereafter be made the subject of a separate me-
moir; the present essay being intended to comprehend only the
laws of bodies magnetized by induction only, and without any
coercive force.

The equations of magnetic equilibrium, formed in the way that
has been described, are at first somewhat complicated; but by
means of certain transformations, the triple’ integrals which they
contain are reduced to double integrals, and the equations become
much more simple, We then deduce this general consequence
from them, that notwithstanding the boreal and austral fluids are
distributed throughout the mass of a body magnetized by induction,
the attractions and repulsions which it exercises externally are the
same as if it were merely covered by a very thin stratum formed
of the two fluids in equal quantities, and such that their total ac+
tion upon all the points within them should be equal to nothing,
If the body contains an empty space within it, and if there are
centres of magnetic force within this space and without the body,
it must be considered as terminated by two thin strata, correspond-
ing to the exterior and interior surface, and the action of these two
Strata on any point of the substance, joined to that of all the given

328 Astronomical and Nautical Collections.

centres of magnetic action, must produce a perfect equilibrium:
in this case, the two fluids may be in different quantities in each
of the thin strata, provided that they be always in equal quantities
in the two surfaces taken together. In this manner the theory of
magnetic attractions and repulsions is reduced to the same princi-
ples, and is made to depend on the same formulas with the theory
of electric forces in conducting bodies; being only a particular case
of these problems. But in the case of electricity the proposition
here laid down is the original foundation of the theory, while in
magnetism, on the contrary, it is a consequence deduced from
the equations of equilibrium obtained by means of other consi-
derations.

It may also be remarked that, according to this general propo-
sition, if we had a collection of small masses of metal, or of any
conductor of electricity, of dimensions so small that they might be
neglected in comparison with those of the whole collection or ag-
gregate, and each being surrounded by a substance capable of
restraining the passage of the electricity from one to the other, but
not sensibly adding to their volumes; and supposing the aggregate
thus constituted to be brought near any electrified body; it would
then become electrical by induction, and in this state, the attractions
and repulsions, which it would exert externally, would be the same
with those of a simple conducting body of the same form, subjected
to the same external forces, although in the one case the two elec-
tric fluids would be transferred to opposite extremities of the body,
and in the other they would be obliged to remain in the constituent
masses to which they originally belonged. This supposed consti-
tution of an electrical body is well calculated to give us a distinct
idea of the disposition of the two magnetic fluids in a magnetized
body.

Upon applying the general formulas of this memoir to the case
of a hollow sphere, of which the solid part is of an uniform thickness,
‘a remarkable theorem is deduced from them, which is applicable
both to magnetism and to electricity. Suppose such a sphere to
be formed of a conductor of electricity, and suppose electrified

Astronomical and Nautical Collections. 329

bodies to be distributed in any manner whatever within or without
the hollow sphere; the sphere will be electrified by induction and
the effect will be such that:—

1. When all the electrified bodies are without the hollow sphere,
their action, joined to that of the sphere, will give a result rquat
tro zexo for all the space WITHIN THE CONCAVITY, as well as for
the solid part of the sphere.

2. When, on the contrary, all the electrical bodies are placed in,
the interior concavity, the result of their action joined to that of the
sphere, on a point without, will be a consTanT Force all around
the body ar EQUAL DISTANCEs from its centre, and the same as if
the whole of the two electric fluids were united in this point. The
thickness of the electric stratum will be the same in all the extent
of the exterior spherical surface, notwithstanding the different dis-
tances of its different parts from the electrified bodies within ; and
if the electricity passes by aspark from one of these bodies to ano-
ther, or into the spherical shell, the exterior attractions and repul-
sions will not be changed.

Wir REGARD TO MAGNETISM, IT FoLLOWS FROM THIS THEO-
REM THAT A MAGNETIC NEEDLE PLACED IN THE INTERIOR
OF A HOLLOW SPHERE OF SOFT IRON, anv so smaLu
AS NOT TO EXERT ANY SENSIBLE INFLUENCE ON THE SPHERE,
WILL NOT BE SUBJECT TO ANY MAGNETIC ACTION, AND. WILL
consEquentTLy NOT EXHIBIT ANY POLARITY. rvrom tur
EFFECT OF THE EARTH’S MAGNETISM, OR FROM THAT OF ANY
OTHER MAGNETS PLACED WITHOUT THE HOLLOW SPHERE. It
follows also that if magnets are placed within such a sphere, their
action on a small needle without it, joined to that of the shell itself
as magnetized by their influence, will always produce a result
equal to zero; for, from the second part of the theorem, the ex-
terior action must be the same as if the boreal and austral fluids
were both united in the centre of the sphere; which would neu-
tralise their action at all distances, since these fluids are always
necessarily present in equal quantities. And if we consider a plane
as a sphere of infinite radius, we may infer that the interposition of
a plate of soft iron of any given thickness, but of a great extent,

330 Astronomical and Nautical Collections.

must be sufficient to prevent the transmission of the maenetic
action; so that a strong magnet being placed on one side of such
a plate, and at a great distance from its extremities, a small piece
ofiron placed on the opposite side would neither be attracted nor
repelled ; and on this side they would not adhere to the plate of
iron, while they might adhere strongly to the ide next the magnet,
although the thickness of the plate, or the distance between these
surfaces, might be very inconsiderable. [It is to be presumed that
this corollary is demonstrated in the original memoir; for it is by
no means self evident that the remoter portion of the supposed
infinite sphere would be without all effect, notwithstanding its in-
finite distance, especially as it has been before observed that the
thickness of a stratum of electricity would be the same in every
part of the spherical surface. ]

The most simple case, to which the formulas of this memoir can
be applied, is that of a hollow sphere, magnetized by the action of
the earth, that is to say, by the action of a force of which the ori-
gin is very remote, and which may be considered, for this reason,
as constant in magnitude and in direction throughout the extent of
a magnetized body of ordinary dimensions. In this case, the in-
tegrations are capable of being expressed in a finite form: the
equations of magnetic equilibrium are completely resolved, and we
obtain from them all that is required to be known, either with re-
gard to the direction of the lines of polarity, and to the intensity
of the magnetism, in the solid part of the sphere; or with regard
to the action which it exerts externally upon any point given in
position. This memoir contains the expression of the three ortho-
gonal component forces of this external action, whence it was easy
to infer, by adding them to the terrestrial force, as resolved in a
similar manner, the true directions of the horizontal needle, and of
the dipping needle, as well as the duration of their oscillations ina
given position, which will afford the simplest manner of comparing
the theory withexperiment. Although the magnetism is not confined
to the exterior surface of the hollow sphere, and although its intensity
may be determined for any point of the solid shell, yet the magnitude
of the three component forces produced by it is WHOLLY INDEPEN=

Astronomical and Nautical Collections. 331

DENT OF THE THICKNESS OF THE METAL: it is determined only
by the radius of the external surface, and by the co-ordinates be-
longing to the position of the point on which the forces act. When
the distance of this point from the centre of the sphere is very great
in comparison with the radius, each of the three forces is very
nearly as the cube of the radius directly, and as the cube of the
distance inversely. Wemay reduce them to two, one directed to
or from the centre of the sphere, the other coinciding with the di-
rection of the dipping needle. The former vanishes when the point
of action is situated in the plane passing through the centre of the
sphere, and perpendicular to the latter: hence it follows that if a
small magnetic needle be placed in this plane, the direction which»
it would assume, in virtue of the action of the earth, will not be
altered by the attraction of the sphere. We must, however, be
careful to avoid inferring from this circumstance that this attraction
vanishes in the supposed plane; for the second elementary force
does not vanish at the same time with the first; it will be sub-
tracted from the action of the earth, and its effect will be to retard
more and more the oscillations of the needles, in proportion as the
needle is brought nearer and nearer to the sphere. At the surface
itself, and in any plane intersecting it, this foree is equal and
contrary to the action of the earth; so that in this situation the
little needle will only be urged in the direction of the radius: and
in the plane perpendicular to the dipping needle, and very near the
surface of the sphere, the needle would be exempt from all magnetic
action, and would have no determinate direction, provided, however,
that it were so small as to have its influence on the magnetism of
the sphere inconsiderable.

_ Mr. Professor Barlow, of Woolwich, has lately made. a great
number of experiments on the deviations of the compass, and of the
dipping needle, produced by the influence of a sphere of iron mag-
netized by the influence of the earth. His observations are recorded
in his Essay on Magnetic Attractions, 2 ed. Lond. 1823. They
have enabled him to conclude that the effect on the needle is the
same whether the sphere that produces them is completely solid or
hollow: and at the actual distances of the needle from the sphere,

332 Astronomical and Nautical Collections.

he has found that the tangent of the angle of horizontal deviation is
proportional to the cube of the quotient of the radius of the sphere
divided by the distance of the needle from its centre: results
which obviously afford a confirmation of the theory here laid down.
(He has also observed that the deviations vanish when the middle
of the needle is in a plane passing through the centre of the sphere,
and perpendicular to the dipping needle: but he is incorrect in
calling this plane the plane of no attraction: there is indeed no
plane in which the attraction of a sphere, or in general, of any
body magnetized by the earth’s influence, becomes evanescent). |
In order, however, to compare the theory still more precisely with
observation, a part of the deviations, which Mr, Barlow has deter-
mined, have been calculated from the formule of this memoir : and
the general agreement of the results, with his observations, appears
to leave no doubt either of the accuracy of this theory, or of that
of the analysis which is founded on it. Without entering into the
whole detail of this comparison, it will be sufficient to mention
some particular cases.

The diameter of the sphere of iron magnetized by the action of
the earth being thirteen English inches ; and the needle, of which
the deviations were observed, being six inches long, and its middle
point twelve inches from the centre of the sphere; Mr. Barlow
found, in a certain relative situation of the compass, a horizontal
direction of 36° 15’: in the same relative position, taking into con-
sideration the length of the needle, which is here too great to be
neglected, the computation gives 35° 33’ for the same deviation:
and the difference of 42’ must be partly attributed to the reaction
of the needle on the sphere, which could not be comprehended in
the computation, because the magnetic force of its poles is un-
known.

In a continuation of the same radius, the middle point of the
needle being twenty inches from the centre, the horizontal deviation
was reduced to 8° 52’ by observation; the calculation would make
it 8° 42’, differing only 10’ from the experiment.

At the same distance of twenty inches, and when the needle was
situated near the plane in which the horizontal deviation completely

Astronomical and Nautical Collections. 333

vanishes, this deviation became 1° by observation; while the cal-
culation would make it 59’, which is a nearer agreement than could
have been expected.

If we suppose two planes perpendicular to the magnetic meridian
to pass through the centre of the sphere, the one horizontal, the
other parallel to the dipping needle, the horizontal deviations of
the compass in these two planes will have, according to the theory,
a very simple relation to each other: when the right line joining
the middle of the needle and the centre of the sphere makes the
same angle in either plane with their common intersection, the
tangent of the deviation in the horizontal plane will be to the tan-
gent of the deviation in the other plane, as the cosine of the dip at
the place of observation to unity. Mr. Barlow’s observations suf-
ficiently show the truth of this proposition: thus when the middle
of the needle was eighteen inches from the centre of the sphere,
the experiment gave in the second plane, at the distance of 45°
from the line of east and west, a horizontal deviation of 12° 6’, and
the dip being 70° 30’, it would be inferred that the corresponding
deviation in the horizontal plane should be 4° 6’, while the obser-
vation made it only 4°: the difference of 6’ being probably owing
to the errors of observation.

The same mode of computation has been applied to the dip, as
observed by Mr. Barlow under the influence of the sphere of iron;
and the differences are not greater than are usually found in all
such comparisons. Thus when the dipping needle was placed in
the plane of the magnetic meridian, passing through the centre of
the sphere, and at the distance of twenty inches, making an angle
of 45° with the direction of the earth’s magnetism, the dip was.
reduced from 70° 40' to 67° 40’; the calculation gives 67° 46’
which differs only 6’ from the result of the experiment,

In these numerical computations it has been supposed ; first,
that the action of the earth is the same on the magnetic fluid of the
sphere magnetized by its influence, and on the fluid belonging to
the needle employed; secondly, that the action of the fluid of the
sphere on itself is also equal to the action that it exerts on that of
the needle. It was natural to make these suppositions in the first

Vox. XVII | 2A .

334 Astronomical and Nautical Collections.

instance, and the differences between the calculation and the ob-
servations are not sufficiently great to induce us to abandon them.
Besides, if there were any slight difference of intensity among these
actions, depending on the difference of the materials of which the
sphere and the needle are formed, the observations in question
could scarcely have been sufficiently accurate to determine so de-
licate a point.

The author terminates the abstract of this admirable memoir with
aremark which he thinks may be of some advantage in practice.

The horizontal deviation of the needle, produced by the influ-
ence of the magnetized sphere, and the relation of the number of:
oscillations which it makes when so influenced to the number of
its spontaneous oscillations, comprehend, in their analytical ex-
pressions, that of the dip at the place and time of observation: so
that by making the deviation and the ratio of the variations equal
to the values obtained by observation for a known situation of the
needle, we may obtain two equations, either of which might serve to
compute the dip. If we employ the ratio of the oscillations, we
have the advantage of being able to obtain it by observation, with
sufficient accuracy, from a needle so small ‘as to be incapable of
sensibly affecting the magnetism of the sphere. The equation to be
resolved, in order to obtain the dip, will contain the diameter of the
sphere, and the distance from its centre; both which may be mea-
sured with great precision: it will also comprehend the two angles
which determine the line of direction of the needle from the sphere:
but when the needle is near the point which affords the maximum of
action, a small error in the direction of this line will have little in-
fluence on the magnitude of the dip, which may be determined by
the method here described with more accuracy and ae than by
direct observation.

A second memoir is intended to contain a determination of the
mode of distribution of magnetism in needles of steel magnetized to
saturation, and in needles of iron magnetized by induction, by
means of the same general theorems that have been demonstrated
in the present essay ; and from these distributions the phenomena
of their mutual attractions and repulsions will be deduced, upon
similar principles.

339

Arr. XIII. ANALYSIS OF SCIENTIFIC BOOKS.

I. Meteorological Essays and Observations, by J. Frederick Daniell,
F.R.S, London: Underwoods, 1823. 8vo. Pp. 479. Three
Plates,

“¢ Man,” as Mr. Daniell has correctly observed at the commence-
ment of the work before us, ‘* may almost with propriety be said to
be a meteorologist by nature; he is actually placed in such a state
of dependance upon tke elements, that to watch their vicissitudes and
anticipate their disturbances, becomes a necessary portion of the
labour to which he is born. The daily tasks of the mariner, the
shepherd, and the husbandman, are regulated by meteorological
observations ; and, the obligation of constant attention to the changes
of the weather, has endued the most illiterate of the species with a
certain degree of prescience of some of its most capricious alterations.
Nor, in the more artificial forms of society, does the subject lose
any of its universality or interest: much of the tact of experience,
indeed, is blunted and lost; but artificial means, derived from
science, suppiy, perhaps inadequately, the deficiency; and the
general influence is still felt and acknowledged, though not ac-
curately appreciated. The generality of this interest is indeed so
absolute, that the common form of salutation amongst many nations
is a meteorological wish, and the first introduction between strangers
a meteorological observation.”

The important modifying influence exerted over the human frame
by different conditions of the atmosphere; the comparative hilarity
and corporeal energy communicated by one variety of weather, and
the languor and oppression experienced in another, have long at-
tracted the regards of philosophers to the investigation of the origin
of many of those diseases, especially of an epidemic nature, which
affect mankind. Hitherto, however, but little positive information
has been derived from the inquiry; the precise physical condition—
the exact constitutio aéris, exerting a baneful influence over health,
being still enveloped in uncertainty.

The various eudiometrical experiments which haye been instituted
in sickly climates and seasons having failed to elucidate the subject,
the same constituent gaseous principles, and the same proportion
of those constituents having been found as in a healthy atmosphere,
it has been supposed by the author before us, that an accurate
method of estimating the varying quantity of aqueous vapour in the
elastic medium which surrounds us—the only fluctuating ingredient
of its composition, might lead to some useful hints on this interesting
subject, and suggest in some important diseases, in those of the lungs

2H 2

336 Analysis cf Scientific Books.

more especially, the construction of an artificial atmosphere, of greater
efficacy than any that has hitherto been recommended.

It is to be feared, however, that such knowledge might not lead to
results as valuable as might at first be imagined. Jt would not seem
that air highly charged with aqueous vapour, if unaccompanied with
excessive heat or cold, or noxious exhalations, is remarkably inju-
rious to human health. In the marshy districts not only in this
country, but universally, consumptions are comparatively rare, and
considerable benefit has been derived from sending phthisical indi-
viduals from dry and lofty districts, into others where the atmo-
sphere has been more charged with humidity. Pisa is chiefly on
this account one of the most genial climes in the south of Italy for
consumptive subjects, although in cther respects extremely un-
healthy, owing to the malaria exhaled by the surrounding marshy
districts. Were accurate registers, however, taken of the compara-
tive barometric, thermometric, and hydrometric variations, and the
corresponding states of public health or disease correctly registered,
as might be readily done in some of the large valetudinarian esta-
blishments of this country; considerable advantage would inevitably
follow, if not in a therapeutical at all events in an hygienic point of
view. Unfortunately, meteorology has heretofore been but little
studied as a science, and although many of its parts have been ably
elucidated by several existing philosophers, amongst whom the
author of the volume before us stands especially conspicuous, yet
it must be considered to be still in its infancy. -

The three first sections of this scientific production are occupied
by an elaborate disquisition on the constitution of the atmosphere, of
which it is impossible for us to give more than a recapitulation of
the principal conclusions to which the author has arrived, after a
patient investigation of the researches of the most eminent philoso-
phers, conjoined with the results of his own observations.

The grand conclusions are as follows:—There are two distinct
atmospheres, mechanically mixed, surrounding the earth, whose
relations to heat are different, and whose states of equilibrium, con-
sidering them as enveloping a sphere of unequal temperature, are
incompatible with each other. The first is a permanently elastic
fluid, expansible in an arithmetical progression by equal increments
of heat, decreasing in density and temperature according to fixed
ratios, as it recedes from the surface, and the equipoise of which
under such circumstances, would be maintained by a regular system
of antagonist currents. The second is an elastic fluid, condensable
by cold with an evolution of caloric, increasing in force in geometrical
progression with equal augmentations of temperature : permeating the
former and moving in its interstices, as a spring of water flows
through a sand-rock. When in a state of motion, this intestine
filtration is retarded by the znertia of the gascous medium, but in a
state of rest the particles press only upon those of their own kind.

.

Meteorological Essays and Observations. 337

The density and temperature of this fluid have also a tendency to
decrease, as its distance from the surface augments by a rate less
rapid than that of the former: Its equipoise would be maintained
by the adaptation of the upper parts of the medium, in which it
moves, to the progression of its temperature, and by a current flow-
ing from the hotter parts of the globe to the colder. Constant eva-
poration on the line of greatest heat, and unceasing precipitation at
every other situation, would be the necessary accompaniments of this
balance. ‘The conditions of these two states of equilibrium, to which,
by the laws of hydrostatics each fluid must be perpetually pressing,
are essentially opposed to each other. The vapour or condensible
elastic fluid is forced to ascend in a medium, whose heat decreases
much more rapidly than its own natural rate : and, it is consequently
condensed and precipitated in the upper regions. Its latent caloric
is evolved by the condensation, and communicated to the air; and
it thus tends to equalize the temperature of the medium in which
it moves, and to constrain it to its ownlaw. ‘This process, the
author considers, must evidently disturb the equilibrium of the per-
manently elastic fluid, by interfering with that definite state of tem-
perature and density which is essential to its maintenance. ‘The
system of currents is unequally affected by the unequal expansion,
and the irregularity extended, by their influence, much beyond the
sphere of the primary disturbance. The decrease of this elasticity
above, is accompanied by an extremely important re-action upon the
body of vapour itself, being compelled to accommodate itself to the
circumstances of the medium in which it moves, its own law of dene
sity can only be maintained by a corresponding decrease of force
below the point of condensation ; so that the temperature of the air,
at the surface of the globe is far from the term of saturation; and
the current of vapour which moves from the hottest to the coldest
points, penetrates from the equator to the poles, without producing”
that condensation in mass, which would otherwise cloud the whole
depth of the atmosphere with precipitating moisture. The clouds
are thereby confined to parallel horizontal planes, with intermediate,
clear spaces, and thus arranged are presented to the influence of the
sun, which dissipates their accumulation, and greatly extends the
expansive power of the elastic vapour. ‘The power of each fluid
being in proportion to its elasticity, Mr. Daniell considers that of the
vapour compared with the air can never exceed at most 1.30; so
that the general character of the mixed atmosphere is derived from
the latter, which in its irresistible motions must hurry the former
along with it. The influence, however, of the vapour upon the air,
though slower in its action, is sure in its effects, and the gradual and
silent procgsses of evaporation and precipitation govern the boisterous
power of the winds. By the irresistible force of expansion unequally
applied, they give rise to undulations in the elastic fluid; the return-

338 Analysis of Scientific Books.

ing waves dissipate the local influence, and the accumulated effect is
annihilated, again to be produced.

«¢ In tracing the harmonious results of such discordant operations,”
eloquently observes our author, ‘ it is impossible not to pause, to
offer up a humble tribute of admiration of the designs of a beneficent
Providence, thus imperfectly developed in a department of creation
where they have been supposed to be the most obscure. By an
invisible, but ever active agency, the waters of the decp are raised
into the air, whence their distribution follows, as it were by measure
and weight, in proportion to the beneficial effects which they are
calculated to produce. By gradual, but almost insensible, expansions,
the equipoised currents of the atmosphere are disturbed, the stormy
winds arise, and the waves of the sea are lifted up; and that stagna-=
tion of air and water is prevented which would be fatal to animal
existence. But the force which operates is calculated and propor-
tioned: the very agent which causes the disturbance bears with it
its own check; and the storm, as it vents its force, is itself setting the
bounds of its own fury. The complicated and beautiful con-
trivances by which the waters are collected above the firmament,”
and are at the same time “divided from the waters which are
below the firmament,” are inferior to none of those adaptations of
INFINITE Wispom, which are perpetually striking the inquiring
mind, in the animal and vegetable kingdoms. Had it not been for
this nice adjustment of conflicting elements, the clouds and concrete
vapours of the sky would have reached from the surface of the earth
to the remotest heavens; and the vivifying rays of the sun would
never have been able to penetrate through the dense mists of perpe-
tual precipitation.”—P. 132.

The reference to this admirable and complicated agency by which
the different constituents of the atmosphere are so beautifully and
regularly balanced, leads the author to the consideration of a sub-
ject which has always been a favourite with the sceptic, and on
which we must necessarily continue to remain in considerable doubt
and conjecture: still, the philosophical explanation which Mr.
Daniell adopts, along with Mr. Granville Penn, to whom he ex-
presses himself indebted for the first idea of it, appears to us the
most probable of any that has been propounded, and the most con-
sistent with those principles which are known to regulate the aérial
fluid.

** The question has been asked,” says: the author, ‘* How is it
that light is said to have been created on the first day, and day and
night to have succeeded each other, when the sun has been de-
scribed as not having been produced till the fourth day ? The scep-
tic presumptuously replies, this is a palpable contradiction, and the
history which propounds it must be false. But Moses records that
God created on the first day the earth covered with water, and did

Meteorological Essays and Observations. 339

not till its second revolution upon its axis, call the firmament iuto
existence. Now, one result of the previous inquiry has been, that
a sphere unequally heated and covered with water, must be enve-
loped in an atmosphere of steam, which would necessarily be turbid
in its whole depth with precipitating moisture. The exposure of
such a sphere to the orb of day would produce illumination upon it,
that dispersed and equal light, which now penetrates in a cloudy day,
and which indeed is * good :” but the glorious source of light could
not have been visible from its surface. On the second day the
permanently-elastic firmament was produced, and we have seen that
the natural consequences of this mixture of gaseous matter, with
vapour, must have been, that the waters would begin to collect
above the firmament, and divide themselves from the waters which
were below the firmament. ‘The clouds would thus be confined to
definite plains of precipitation, and exposed to the influence of the
winds, and still invisible sun. The gathering together of the waters
on the third day, and the appearance of dry land, would present a
greater heating surface, and a less surface of evaporation, and the
atmosphere during this revolution would let fall its excess of con-
densed moisture: and, upon the fourth day it would appear pro-
bable, even to our short-sighted philosophy, that the sun would be
enabled to dissipate the still-remaining mists, and burst forth with
splendour upon the vegetating surface. So far, therefore, is it from
being impossible that light should have appeared upon the earth
before the appearance of the sun, that the present imperfect state of
our knowledge will enable us to affirm, that, if the recorded order of
creation be correct, the events must have exhibited themselves in the
succession which is described. ‘The argument, therefore, recoils with
double force in favour of the inspiration of an account of natural
phenomena, which in all probability, no human mind, in the state of
knowledge at the time it was delivered, could have suggested; but
which is found to be consistent with facts that a more advanced state
of science and experience have brought to light.” P. 134.

The important modifying influence exerted over atmospheric phe-
nomena by the electric fluid and the moon, are not entirely passed
over by our author in his interesting inquiry, although he has not
been able to add any thing to our existing stock of knowledge on
the subject : from those experiments, however, instituted by him, he is
inclined to believe that the elasticity of vapour is increased when elec-
trically charged, but on this point he has nothing decisive to offer.
The popular and general opinion of the different phases of the moon
possessing an influence over atmospherical vicissitudes which has
been denied by some philosophers, and considered as the offspring of
superstition and ignorance, is attentively considered by the author,
and accorded with. Innumerable observations have shewn that such a
relationship does actually exist, and it is not at all more extraordinary
than the influence exerted over the tides by that satellite.

340 Analysis of Scientific Books.

Of the next essay, “ On the Construction and Uses of a New
Hygrometer,” we shall say but little ; the ingenious ideas which led
to its adoption: its mechanism and uses have been already detailed
in this Journal, by the author, and the practical observations made
with it in different portions of the globe, communicated by different
scientific individuals through the same channel. To those, however,
who have not perused Mr. Daniell’s description of the instrument,
the essay before us will afford every necessary information regarding
its construction, and mode of employment.

The author complains, and not without justice, of the difficulties
experienced in * approaching the shrines whence the oracles of
science are issued,” and relates the following anecdote which we
wish were unique: unfortunately, it is not the first instance by many
where obstructions have been experienced in the fair investigation of
philosophical discoveries by the academy in question, and frequently,
we fear, from an overweening desire to promulgate the discoveries
of their countrymen, and a corresponding apathy towards those of
other nations.

« Being actuated,” says Mr. Daniell, ‘* by the wish to obtain
contemporaneous observations, and to do all in my power to facili-
tate so desirable an object, and my own opinion being confirmed by
those whose judgment I could not doubt, I took an opportunity of
sending by a private hand, two of the hygrometers, in their most
perfect state, to one of the philosophers of the French Royal Aca-
demy of Sciences, the most distinguished for chemical knowledge
and discoveries. I requested his opinion of the merits of the instru-
ment, and authorized him to present one of them, in the most:-re-
spectful way to the Academy. My presumption has, I suppose, been
P operly checked, by no notice whatever having been taken of what
was certainly meant as a mark of humble respect, either by the in-
dividual, or the learned body: to the former of whom, having had
the advantage of a personal introduction, I cannot feel that I have
been to blame in addressing myself, however small may have been
my pretensions for obtruding myself upon the latter.” P. 185.

The next essay to which we shall advert, comprises a dissertation
on the climate of London ; a subject not less interesting to the lover
of meteorology as a science, than to the physician; there are,
however, so many circumstances independently of the exact con-
dition of the atmosphere as. regards temperature and dryuess,
which exert a baneful influence over human health, that these phe-
nomena are not so decisive in the study of causation as might @ priore
be imagined : it has indeed been asserted by some philosophers that
the greater salubrity of one country over another is principally owing
to the lesser degree of noxious emanations from its soil ; and Heberden,
Blane, and others, have affirmed that on the whole, except in the
case of extraordinarily cold winters, the fluctuations of the weather in
this climate do not much affect health, Still epidemics do occur,

Meteorological Essays and Observations. 341

which there is every reason to suppose have been occasioned by
atmospherical changes, and consequently, as we have observed in a
former part of this article, if these variations, barometrical, thermo-
metrical, and hygrometrical, were carefully and regularly arranged
at corresponding periods, and the changes in the condition of public
health accurately marked, some very interesting and valuable informa-
tion might in ali probability be obtained, not less important to the
physician than to mankind in general,

We can only enumerate here these general characters of the climate
as adduced by Mr. Daniell, on an average-of three successive years.
The monthly phenomena are given, accompanied with popular obser-
vations on the corresponding conditions of the weather, the state of
vegetation, health, &c.: but for those we must refer the reader who
may be anxious to peruse them, to the work itself.

‘The observations were made three times a day, viz., from eight to
ten o’clock A. M., from half past three to half past five P. M., and
from ten to half past eleven P. M.

The mean pressure of the total atmosphere as denoted by the baro«
meter was found to be 29,881 inches: the mean of twenty years,
deduced by Mr. Howard from the observations of the Royal Society
being 29.8655 inches. The mean temperature derived from the
daily maxima and minima of the thermometer was 4,9°.5, correspond=
ing even to the decimal place with Mr. Howard’s estimate. The
mean dew-point was 44°.5, as also calculated from the daily maxima
and minima. The elastic force of the vapour was consequently
0.334 inch, and a cubic foot of the air contained 3.789 grains of
moisture. ‘The degree of moisture was represented by 5° upon the
thermometric scale, and the degree of moisture by 850 upon the
hygrometric. The average quantity of rain was 22.199 inches, and
the amount of evaporation calculated from the hygrometer, 23.974
inches; and the weight of water, raised from a circular surface of
six inches diameter, 0.31 grains per minute.

The Barometric range was from 30.82 inches to 28.12 inches : the
range of the dew-point from 70° to 11°. The pressure of the vapour
varying with it from 0.770 inch, to 0.103 inch. The maximum tem-
perature of the air was 90°, the minimum 11°, The force of radiation
from the sun averaged 23°.3 in the day, and that from the earth at
night 4°.6: the highest temperature of the sun’s rays was 154°, and
the lowest temperature on the surface of the earth 5°. The greatest
degree of dryness was 29°, or the least degree of moisture upon the
hygrometric scale 389. The time of the day was found, in some
degree, to influence the near results; and one of the most constant
eflects was that produced upon the barometer. The mercurial column
reached its greatest height in the morning, declined to its lowest in
the afternoon, and again rose at night. The average difference of
these periods, as exhibited by the journal, was as follows :—Morning
above night +.005 inch ; afternoon below morning —.015 inch ;

342 Analysis of Scientific Books.

night above the aflernoon +.010 inch. ‘The means of the monthly
observations presented but one or two exceptions to the fail in the
middle of the day, or to the rise from afternoon to night ; but the rise
from night to morning was not quite so constant.

With regard to the dew-point, four observations were made daily,
including the observation of the minimum temperature, which con-
stantly falls a few degrees below the term of precipitation taken in the
day. From morning to afternoon it was found to rise but 0.3 of a
degree; from afternoon to night it fell 0.9 of a degree; and below
this again, the minimum temperature was 2.7. Tle mean was calcu-
lated from this and the afternoon observation.

The temperature of the air was found to vary in the twenty-four
hours from 569.1, its mean maximum to 4.2°.5 its mean minimum.

“The mean temperature of a climate,” says our author, ‘ is ge-
nerally regarded as made up of the average impression of the sun due
to its latitude upon the surface of the globe. The mean quantity of
aqueous vapour must also be referable, finally, to the same principle.
But there is another way of considering the subject more accurate in
detail, though upon an average of years ending in the same conclu-
sion: that is, to regard the mean temperature as made up of the tem-
perature of different currents flowing from different points of the
compass; and it will be necessary to my purpose to contemplate the
atmosphere of vapour particularly, in this point of view. The medium
dew-point 44°.5 is therefore made up of the following proportions of
the means from eight points of the wind :—

Oo
87 North 40.1 — 133 North-east 40.7
80 East 42.3 — 111 South-east 45.6
70 South 48.7 — 225 South-west 48.6

215 West 44,8 — 174 North-west 41.3

“* Before I enter upon the consideration of the effect of the sun’s
progress in declination, and the succession of the seasons, I shall en-
deavour to point out the influence of the geographical situation of the
island of Great Britain upon its aqueous atmosphere. The mean
quantity of the vapour follows exactly the changes of the mean
monthly temperature, that is to say, the dew-point rises and falls
with the increase and the decrease of the heat. But the winds which
transport the vapour, may be divided into two classes; namely, the
Jand-winds which blow from off the great continent of Europe, and
which comprise the north-east, the east, and south-east; and the sea-
winds which blow from the great oceans which surround it on every
other side, viz., the north, north-west, west, south-west, and south.
In the former we may expect to find that the course of the mean
temperature is exactly followed; for the sources of the vapour must
be comparatively shallow streams, and reservoirs of water, whose
temperature must soon adapt itself to that of the surrounding air.

Meteorological Essays and Observations. 343

But in the unfathomable depths which supply the latter, the law by
which the density of water is regulated, must, at particular seasons,
maintain a temperature above the mean of the declining season ;
whilst at others, the increasing heat of the latter must outstrip the pro-
gress of the former. The following Table contains the dew-point of
the several winds, divided into the two classes for every month in the
year, beginning with the autumnal quarter.

TaBLeE I. Shewing the Difference of the Dew-point in the Land and
Sea Winds.

Land Winds Sea Winds.
NE. E. S.b, N. N.W. W.S.W.S.
Tis sats BOWIE LITA) FAL LID Slat) aitae ro)
CDCI UOTE oe gah bey 4) 0 53 53
CTO er Et anaes tas 3 45 AO
IN OVEIMDEIs sae wend ac leet Al AQ
Wecemberi.nts: «)ia.0\ ene 3i (37
SP ATUAU oe on ee 29 35
REDruary Fs Bad yl 35
Wet ia nce cies eh a 34 38
12.3 a ae ner ah 45 42
psi amt Pils baa SD. pei AT 44
iho (ee ORR Sap ss3 54 54
MODY PRs 4, a cera ach oA 52 55
DAOUBE 50") G's a e's sb 56 57

“ And here the effect anticipated is clearly perceptible, The vapour
of the land winds, it will be seen, declines in force from September to
January, in which month it reaches its minimum, and from that point
gradually rises till it reaches its maximum in August; and this, it will
be afterwards seen, is the exact progress of the mean temperature of
the air, In the sea-winds the vapour follows the same course from
September to November, and the balance is such, that the elastic
force of both divisions is nearly the same. The north and south winds
neutralize each other; and the north-west, west, and south-west, are
equivalent to the north-east, east, and south-east. Having descended
to about 40°, which is somewhere about the point of greatest density
in water, in November, the accordance proceeds no further, In
December, the vapour from the land has descended six degrees below
that from the sea, and the difference continues in January. In Febru-
ary the former rises two degrees, and the latter remains stationary.
The differerice of four degrees continues through March, and is di-
minished to three degrees in April and May. In June they again
attain their former equality. The reason of this is obvious; the tem-
perature of 40° being that of the greatest density, cannot be lowered
tll the whole mass of the waters has passed this term; and in the

344 Analysis of Screntifie Books.

deep seas, this must necessarily be a process of some duration. ‘The
shallow waters, on the contrary, soon assume the temperature of the
ambient air, and continue to decline with it in heat. Upon the return
of spring the contrary effect is produced. ‘The great deeps must again
repass the fortieth degree before the superficial waters can take the
higher temperature of the incumbent atmosphere, ‘I'he consequences
we should expect from this progression, would be an increase of '
humidity in December and January, and a rapid decrease in the four
following months; an expectation which we shall find correct in our
further inv estigation.

‘“< There is another law of the aqueous fluid, which we ae also
expect to have an influence upon the emission of its stcam—the evo-
lution, namely, of heat in the process of congelation, and its absorp-
tion during the liquefaction of ice. ‘The British» Isles are placed in
such a position as would induce us to suppose that, at particular sea-
sons of the year, this influence might be perceptible in one direction
more than in any other. We may bring this idea to the test, by com-=
paring together the northerly and southerly Ww Anas as is done in the
following table : —

Tasez II, Shewing the Effect of the Ice in the North Seas upon the

Dew Point.
SWS SE. NE NNW.

fe)
September ......+.- 58
CUGEQHEE Ne. 5) -efick'e\ oie. nl
November ......... 47
December's: veyai-e 34/6 42
SHIMIAEY a hg tate apse 38
LECT dese le arate 36
IWATE cee ci ajaanie Core 42
ee RR REE Re aS A7
IVES chepicn aenebt>. msuiey's 51
UME th he. o.ossai es \90 hs 58
POLY | 5) ahs use woe nies 58
11 eR A RR ea 60

‘« Here we may observe, that the decline of the vapour from Sep-
tember to December is exactly equal in both classes, but from that
time it ceases about the temperature of 32° in the northerly winds, and
continues in the southerly to the month of February. In March,
again, the temperature of the latter has increased from the minimum
6°, but in. the former it still remains at 32°. In April, on the con-
trary, the increase in the northerly winds excecds that of the
southerly ; and in May, they have again attained their original relative

Meteorological Essays and Observations. 345

distances and resume their parallel progression. Tt would be difficult,
I think, ‘to assign any other cause for this modification of ‘the phe-
nomena than the one which has just been suggested. The evolution
of heat, in the process of freezing, stops the decline of the tempera-
ture in the regions exposed ‘to its influence, while it proceeds in those
which are not exposed to the change; and the absorption of heat in
the operation of thawing, prevents the accession of temperature which
is due to the returning influence of the sun. When this operation has
ceased, the vapour quickly attains its former relative degree of force.
Wonderful adjustments these, to mitigate the rigours of 2 northern cli-
mate! They both operate from November to February, by the evo-
lution of heat in the coldest season of the year; and at the same time,
by an extra supply of vapour, decrease the degree of dryness, and
prevent the consumption of heat which always attends the process of
evaporation.” P. 273. ‘

The next essay to which we shall draw attention relates to a subject
of a more practical nature, and comprises some information of con-
siderable utility to the meteorologist ; it is entitled, “ Remarks upon
the Barometer and Thermometer, and the Mode of using Meteorological
Instruments in general.” Than Mr. Daniell no one is more compe-~
tent to furnish valuable hints on this matter, from a considerable por-
tion of his attention having been given to the manufacture of baro-
meters. The Committee of the Royal Society, appointed to take
into consideration the state of the meteorological instruments, did the
author the honour to request him to attend to the construction of a
new barometer for their apartments, and in the course of this inquiry
he had, of course, an opportunity of making many extremely valuable
practical observations.

In the course of the experiments, he was led to a new method of
filling the tube, of greater facility and correctness ; for the particulars
of which we must refer to the book itself. It consists in conducting
the process ix vacuo, and the author has but little hesitation in con-
sidering it as accurate as the method of boiling, if performed with
proper care, whilst it is infinitely less troublesome and hazardous.
The electric light is as strong in the tube, and its appearance, in every
respect, as perfect.

The following remarks on the faulty construction of meteorological
instruments in general, are extremely just and important.

“* The generality of observers are but little aware of the serious
inaccuracies to which those instruments are liable, In the shops of
the best manufacturers and opticians I have observed that no two
barometers agree ; and the difference between the extremes will often
amount to a quarter ofan inch; and this with ail the deceptive ap-
pearance of accuracy, which a nonius, to read off to the five hundredth
part of an inch can give. The common instruments are mere play-
things, and are, by no means, applicable to observations in the pre-
sent state of natural philosophy. ‘I'he height of the mercury is never

346 _ * Analysts of Scientific Books.

actually measured in them, but they are graduated one from another,
and their errors are thus unavoidably perpetuated. Few of them
have any adjustment for the change of level in the mercury of the
cistern, and in still fewer is the adjustment perfect: no neutral point
is marked upon them, nor is the diameter of the bore of the tube
ascertained ; and in some the capacity of the cisterns is perpetually
changing from the stretching of a leathern bag, or from its hygrome=
tric properties. Nor would I quarrel with the manufacture of such
play things; they are calculated to afford much amusement and in-
struction ; but all I contend for is, that a person, who is disposed to
devote his time, his fortune, and oftentimes his health, to the enlarge-
ment of the bounds of science, should not be liable to the disappoint-
ment of finding that he has wasted all, from the imperfection of those
instruments, upon the goodness of which he conceived that he had
good grounds to rely. The questions now of interest to the science of
meteorology require the measurement of the five hundredth part of an
inch in the mercurial column; and, notwithstanding the number of
meteorological journals, which monthly and weekly contribute their
expletive powers to the numerous magazines, journals, and gazettes,
there are few places, indeed, of which it can be said that the mean
height of the barometer for the year has been ascertained to the tenth
part of an inch. ‘The answer of the manufacturer to these observa-
tions is, that he cannot afford the time to perfect such instruments.
Nor can he, at the price which is commonly given; for few people
are aware of the requisite labour and anxiety. But who would
grudge the extra remuneration for such pains? Not the man who is
competent to avail himself of its application, Let the manufacture of
playthings continue, but let there be also another class of instruments
which may rival in accuracy those of the astronomer. It will, no
doubt, be a part of the plan of the Committee of the Royal Society
to establish a standard barometer, and to afford every facility of com-
parison with it: so that any person, for scientific purposes, may have
an opportunity of verifying an instrument; and it is to be hoped that
they may proceed one step further, and take measures for ascertaining
the agreement of the instruments at all the principal observatories, not
only in this country, but in other parts of the world.

‘‘ Nor is it in the construction of barometers only that the mete-
orologist has to complain of that want of accuracy which is so essential
to the progress of his science; the same carelessness attends the manu-
facture of the thermometer, Few people are aware that they are all,
even those which bear the first makers’ names, made by the Italian
artists, who graduate them one from another, and never think of veri-
fying the freezing and boiling points. The bulbs are all blown with
the mouth, and very little attention is paid to the regularity of the
tube. The register thermometers are particularly shamefully deti-
cient. Those of Six’s construction are often filled with some saline
solution instead of alcohol ; and in the best, the spirit is not exposed

Meteorological Essays and Observations. 347

long enough zn vacuo, to disengage the air with which it is mixed,
The consequence is, that it is liable to become liberated, and, of
course, interferes with the results. ‘The original directions of the in-
ventor have also been departed from, as to the proportions of the dif-
ferent parts, and as to the construction of the indices. Those upon
Rutherford’s plan are universally sealed with air in their upper parts,
which acts as a spring against the expansion of the column: the iron
index of one is liable thereby to become oxidated, and adheres to the
glass when the mercury passes it, and it becomes entangled ; while
the spirit of the other being unavoidably mixed with air, when the
pressure is decreased by cold it is disengaged. ‘The air may be again
dissolved by increasing the pressure before a fire, and passing the
bubble backwards and forwards, and, in a state of solution it does not
appear to interfere with the equability of the expansion. This, how=
ever, is not certain; and, at all events, it is liable to re-appear,
and is very troublesome. These imperfections are by no means
necessary consequences of the construction of the instruments,
although the makers are very willing that they should be so con-
sidered; but it requires great care and attention to guard against
them, The general mounting of the meteorological thermometers is
exceptionable in every way; buried as they are in a thick mass of
wood, and covered with a clumsy guard of brass, they can but very
slowly follow the impression of atmospheric temperature. The
establishment of a perfect standard thermometer, which shall be
accessible to all who may wish to consult it, will also, doubtless, be
another object of the Committee of the Royal Society.” P, 368.

Attention to the perfection of instruments, however, as the author
has very correctly observed, will be all in vain, without a proper de-
gree of care and system in making and recording the observations.
The proper hours of the day for observation are indicated by the
barometer; the maximum height of the mercurial column is at about
nine A. M., the mean at twelve, and the minimum at three P, M.
Where an individual has time to make three observations in the day,
these hours should be preferred ; if he can only ebserve twice, the
first and last hours should be the periods; and if only once, noon
should be the time. Even those who merely consult the barometer
as a weather-glass, would, Mr. Daniell asserts, find it an advantage to
attend to those hours; for he has remarked that much the safest
prognostications from this instrument may be derived from observing
when the mercury is inclined to move contrary to its periodical
course. If the column rise between nine A. M. and three P. M., it
indicates fine weather ; if it fall from three to nine, rain may be ex-
pected.

The thermometer should be inspected at the same periods, in ad-
dition to which the author recommends that the maximum and mini-
mum, by register thermometers, should be carefully noted ; the instru-
ments should, of course, be sheltered from every kind of radiation.

348 Analysis of Scientific Books.

The periods of the barometric observation are recommended also for
those of the hygrometer; the mean pressure of the aqueous atmo-
sphere, however, being calculated from the dew-point at three P. M.,
and the lowest temperature at night of the sheltered thermometer.

This Essay comprises also some interesting information on the
change in the freezing point which occurs in time in the best ther- _
mometers, and has been imagined to be owing to the alteration of form
and capacity which the glass undergoes from the pressure of the
atmosphere upon the vacuum of the tube; as well as some remarks
upon the correction to be applied to barometers for the expansion of
mercury and mean dilatation of glass. For information on these points
the reader is referred to the Essay itself.

Independently of the Essays to which we have already adverted,
there are several others of very considerable interest to the philoso-
pher contained in the volume before us; of these our limits will only
admit of an enumeration of the titles; they will be found, however,
not less scientific and important than those on which we have dwelt at
some length. They are,—1. An Essay upon the radiation of heat
in the atmosphere. 2. An Essay upon the horary oscillations of
the barometer. 3. Meteorological observations at Madeira, Sierra
Leone, Jamaica, and other stations between the Tropics, by Captain
EF. Sabine, R.A. F.R.S. 4. Meteorological observations in Brazil,
and in the Equator, by Alexander Caldcleugh, Esq. And 5. Mete-
orological observations upon heights. The work is also concluded by
an excellent meteorological journal for three years, commencing on
the first of September, 1819.

After the analysis and extracts which we have given in the preced-
ing pages, it is almost unnecessary for us to remark on the mode in
which the work is executed. The various subjects, it will have been
observed, are treated of in a manner highly creditable to the talents
and scientific acquirements of the author ; whilst the language is in
gencral elegant and perspicuous ; the reasoning forcible ; and the pro-=
positions, drawn from principles premised, are logical. To the lover
of meteorological science in particular, as well as of natural philosophy
in general, these Essays will be found to form a rich mine of new
and important information,

New London Pharmacopeta. 849

II, A Translation of the Pharmacopeia of the Royal College of Physi-
cians of London, 1824. With Notes and Illustrations, By Richard
Phillips, F.R.S. L. and E. &c., &c.

Considering the materials he has had to work upon, Mr. Phillips
has really given us a very useful book, in his translation, as he calls
it, of the Pharmacopeia; and has shown something of alchemical

power, in respect to the contents of the meagre original. We are
‘ well aware of the talents that exist in the College of Physicians,
and are therefore utterly at a loss to account for the careless imbe~
cility of the productions which are, from time to time, sent forth
under its auspices. Where is Dr. Wollaston? where Dr. Young ?
What has become of Dr. Maton and Dr. Paris? have they no in-
’ terest in the public character of the body which they adorn; or are
they merely careless of its reputation ; or do they leave so weighty a
concern as the publication of the Pharmacopeia to the beadle and
the bookseller? These are questions asked every day, and every
where, and we profess our entire inability to offer to them any
plausible reply. That they are not unjustly asked, we are sorry to say
is but too manifest, from the present edition, which we understand to
be the production of a Committee of the College; and although
some tendency towards improvement is manifest in several of the
processes, the general execution of the work is very unworthy of its
source,

The old preface of the edition of 1809 is unaccountably reprinted,
and attached to the present work; had this preface contained a
history of pharmacy, or a review of former pharmacopeeias, its
retention might have been excusable; but it is, in fact, a poor and
empty production, and particularly inappropriate to the present
state of pharmaceutical science, which has lately made such rapid
and important progress. ‘To illustrate and expound this progress
should have been the business of the preface, if any were thought
necessary. ‘Ihe researches which have led us toa tolerably accurate
knowledge of the substance upon which the activity of opium depends,
and those which have taught us the existence of distinct salifiable
bases in the greater number of narcotic vegetables; the inquiries
instituted with so much success respecting the principles upon which
the active powers of the varieties of Cinchona depend ; and those which
have taught us the importance of iodine, and some of its combinations,
in the treatment of glandular diseases ; all these subjects should have
been touched upon in the preface, if preface there needs must be ;
we ought also to have been informed why the college have not in=
troduced any of these new and active substances; whether they
consider them ineffectual, or dangerously active; why they have
altogether passed them by; why they have retained in the list of
their Materia Medica, sorrel and wood-sorrel, marsh-mallow and
coltsfoot, bistort and cuckoo-flowers, centaury, contrayerva and cow-

Vou, XVII. 2B

350 Analysis of Scientific Books.

hage, carrots, raisins and figs, bay-berries and mulberries, opoponax
and sagapenum, storax, oyster-shells and toxicodendron; why, in
short, so much of the old lumber is suffered to encumber this new
work, while so many useful novelties, which have a place in foreign
pharmacopeias, are omitted. We are fully aware of the mischief
and absurdity of stuffing every new crudity into a pharmacopeeia ;
the Parisian codex amply proves that; but when we know that all
apothecaries are obliged to keep sulphate of quinina and hydriodate
of potash, and acetate of morphia, and that several Fellows of the
College, justly eminent for their skill and extensive practice, prescribe
and ‘haye faith in these compounds, there are, we think, grounds for
the questions we have humbly submitted. Our experience, how-
ever, obliges us to admit that there must be some hidden obstacles
and unseen difficulties in the way of compiling a good and rational
pharmacopeeia ; for, taking it all in all, that of the London college is
perhaps the best extant. Whether to the prevalence of a pugnacious
diathesis, and the impossibility of deciding, when doctors disagree ;
or to the want of co-operation among scientific and practical men, or
to what other cause we are to attribute this fatality, we shall not now
Stop to inquire; perhaps those who have access to the minute-book
of the Committee of the College, are the only persons who can solve
the problem.

Like ancient Gaul, the Pharmacopeia is divided into three parts :
one assigned to some preliminary matters respecting weights and
measures ; the second to the Materia Medica; and the last to the
preparations and compounds, We shall follow Mr. Phillips’ example
in passing over the two former divisions without remark, The third
is subdivided into sections, of which the first treats of * Acids,” alpha-
betically arranged.

The term ‘“ diluted acetic acid” is properly enough applied to dis-
tilled vinegar, but the process of distillation might well have been
rejected ; for all medical purposes a dilute acid, composed of 1 part
of the concentrated acetic acid, contained in the Materia Medica, and
four parts of water, is preferable. Of this mixture, or of distilled
vinegar, the sp. gr. should be about 1009, and 1000 parts should
saturate 145 of crystallized carbonate of soda: 50 grains of real
acetic acid saturate, according to our translator, 153 grains of this
salt, and upon this datum the following is the composition of the
dilute acid of different specific gravities :

Sp. Grav. Real Acid. Water.
1007 3.42 96.58
1009 4.73 95.27
1043 23.67 76.33
1046 28.43 ye Sy

Of these acids, the two first are the average strength of distilled
vinegar, and the two last that of the concentrated acetic acid, as now
generally prepared by the vinegar-makers from pyroligneous acid.

New London Pharmacopeia. 351

Benzoic Acid is an article which might very well be struck out of
the Pharmacopeia ; the process, however, now directed is preferable
to that of the last edition.

A process for obtaining Citric Acid is given in this division, but it
also has a place among the articles of the Materia Medica, and is so
rarely prepared except by the manufacturer upon an extended scale,
that the directions here given might well have been dispensed with.
Mr. Phillips tells us that an ounce of water at 60° dissolves 10
drachms of crystallized citric acid ; and such solution saturates about
20 drachms of crystallized carbonate of soda. Nine drachms and a
half of citric acid dissolved in a pint of distilled water, give, he says,
asolution equal in strength to lemon juice.

Weshall quote the article “* Muriatic acid” entire, that our readers
may judge of the method which the translator pursues in his remarks
and of their general usefulness to students and practitioners,

Muriatic Acid.

“ Take of dried muriate of soda, two pounds,
Sulphuric acid by weight, twenty ounces,
Distilled water, a pint and a half;

*¢ First mix the acid with half a pint of the water in a glass retort, and
to these, when cold, add the muriate of soda; pour the remainder
of the water into a receiver; then, adapting the retort to it, let the
muriatic acid distil into the water from a sand-bath, the heat being
gradually raised until the retort becomes red hot.

“The specific gravity of muriatic acid is to that of distilled water
as 1-160 to 1°000.

“One hundred and twenty-four grains of crystallized subcarbonate
of soda, are saturated by 100 grains of this acid.

** Process.—The nature of common salt, and the production of mu-
riatic acid, are explained by two theories, both of which I shall state,
because, from the name of muriate of soda which the college retain
for common salt, it would appear that, as a body, they have not
adopted the generally-received doctrines of Sir H. Davy on these
subjects.

«© On the supposition that muriatic acid is an undecomposed body,
the explanation of its production is the following: Common salt, or
muriate of soda, is a compound of muriatic acid and soda, and when
it is mixed with the sulphuric acid, this, owing to its greater affinity
for soda, expels the muriatic acid from it, which, being gaseous, and
having considerable affinity for water, rises in the state of vapour
with it, and is condensed in the receiver into liquid muriatic acid.
The sulphuric acid and soda remain in the retort in the state of sul-
phate of soda,

** This process will be explained by the annexed diagram:

i

352 Analysis of Scientific Books.

Liquid Muriatic Acid.
Muriatic Acid. Water.
: Diluted
ees of Sulphuric
Acid

Soda. Sulphuric Acid.

Dry Sulphate of Soda.

“ According to the opinion of Sir H. Davy, now generally adopted,
common salt, or chloride of sodium, is a compound of 36 chlorine
and 24 of the metallic body sodium; liquid sulphuric acid consists
of 40 parts of dry acid and 9 of water, the water being composed of
1 of hydrogen and 8 of oxygen; when these quantities of common
salt and liquid sulphuric acid act upon each other, the water and
chloride of sodium are both decomposed; the 1 of hydrogen uniting
with 36 of chlorine, constitute 37 of muriatic acid gas, and the 8 of
oxygen with the 24 of sodium form 32 of oxide of sodium, or soda.
The 37 of muriatic acid gas combining with the water used in dilut-
ing the acid, rise with it in the state of vapour, and by condensation
in the receiver, liquid muriatic acid is produced; the 40 parts of dry
sulphuric acid uniting with the 32 of soda, form 72 of dry sulphate
of soda, which remain in the retort.

37 Muriatic Acid Gas.
pe
36 Chlorine 1 Hydrogen

§ Oxygen
9 Water
49 Liquid
60 Chloride of Sulphuric
Sodium :
24 Sodium pits
8 Oxygen
— 40 Dry Sul-
32 Soda phuric Acid.
eee. Fo eee

72 Dry Sulphate of Soda.

“¢ In preparing this acid it is, I think, more convenient to mix the
sulphuric acid and water in a separate vessel than in the retort; to
introduce the salt first into the retort and to pour the acid upon it ;
and to put less water into the receiver, and more into the retort.

“ Qualities.—Muriatic acid, when perfectly pure, is colourless ;
it emits white suffocating fumes, which turn vegetable blues red ; its
taste is strongly sour and acrid ; when its sp. gr. is 1°160 as directed
by the college, a fluid ounce weighs about 527 grains; it is stated

New London Pharmacopoeia. 353

that 100 grains saturate 124 of crystallized subcarbonate of soda,
which, from some indirect experiments, I believe to be not quite
correct. _ By the French chemists it is termed hydrochloric acid, to
express its nature. It acts upon and dissolves several metals with
the evolution of hydrogen gas arising from the decomposition of water.
Thus iron, zinc, and tin are readily dissolved by it; it acts but
slowly upon copper, but dissolves its oxides with facility. Its saline
compounds are termed muriates, and most of them suffer decompo-
sition when heated, as I shall explain when describing the properties
of muriate of lime. side

“© Composition.—Muriatic acid gas is composed of equal volumes
of hydrogen gas and chlorine gas; and the combination takes place
without alteration of volume. By weight it consists nearly of

Hydrogen 2°7 or 1 atom of hydrogen .
Chlorine 97°31 do, ofchlorine ..

100°0. Number representing its atom = 37

1
36

“ Liquid muriatic acid of sp. gr. 1:160 is composed of nearly
32:4 of muriatic acid gas, and 67°6 water.

«« Adulteration—This acid, as usually met with, has a yellow
tinge, which is owing either to the presence of chlorine or of peroxide
of iron ; if the former be present, it may sometimes be determined by
the smell, or by its power of dissolving gold leaf; the latter is dee
tected by the addition of solution of ammonia, which, when added
slightly in excess, throws down the peroxide of iron of a reddish
yellow colour. It sometimes also contains sulphuric acid; this is
discoverable by adding a solution of muriate of barytes to a portion
of the acid diluted with 4 or 5 parts of distilled water. This dilution
is requisite, because the acid, when concentrated, attracts the water
from the solution of muriate of barytes, and causing it to crystallize,
gives a fallacious appearance of the presence of sulphuric acid.

** Incompatibles.—This acid is incompatible with alkalies, most
earths, oxides and their carbonates, sulphuret of potash, tartrate of
potash, tartarized antimony, tartarized iron, nitrate of silyer, and
solution of subacetate of lead.

“* Officinal Preparations. —Ferrum Ammoniatum.—Tinctura Ferri

muriatis,
, “ Medicinal usesx—According to Dr. Paris, it may be advanta-
geously employed in malignant cases of scarlatina and typhus,
and, mixed witha strong infusion of quassia, he considers it to be the
most efficacious remedy for preventing the generation of worms.
Dose m, v.— xx. frequently repeated.”

When Mr. Phillips says, “ the nature of common salt and the
production of muriatic acid are explained by two theories,” &c., and
when he speaks ofthe ‘ supposition that muriatic acid is an unde=
composed body,” and afterwards, without expressing any doubts

354 Analysis of Scientific Books.

upon the subject, states, that it is composed of equal volumes of
hydrogen and chlorine, we think that he exceedingly perplexes his
subject, as far as medical readers are concerned ; it is just as if he
were to say that the calcination of a metal may be explained upon
two theories, and then cite the phlogistic and antiphlogistic hypothe-
sis. SirH. Davy’s chloridic theory alone furnishes a consistent ex-
planation of the phenomena above alluded to, and we are sorry to
see the blunders of the oxymuriatic school perpetuated by such a
writer as Mr. Phillips, when even Berzelius has ceded. In other
respects the chemical remarks of the translator are very pertinent
and useful, but we could have wished for information somewhat
more extended in respect to the medicinal uses of the different articles,
and think that the list of ‘‘incompatibles” had better, in most cases,
have been omitted.

Our author’s remarks upon the other acids are very much to the
purpose, and are studded with several originalities useful to the phar=
maceutical chemist. He has made much use of diagrams, and has
given wood-cuts of the usual crystalline forms ; we, however, rather
doubt their use, and are certain that neither the apprentice nor his
master will ever refer to the relations of the several plane surfaces to
each other, which are given with an elaborate minuteness incompa-
tible with the general tenor of the work.

The officinal acids of the present Pharmacopaia are seven, viz., the
acetic, benzoic, citric, muriatic, nitric, sulphuric, and tartaric. Might
not the hydro-cyanic have been properly added ? Alkalies and their
salts are treated of in the second division of this part of the Pharma-
copwia. Mr. Phillips has unnecessarily embarrassed his observations
on the subcarbonate of ammonia, by giving the wrong as well as the
right theory of its formation, but in other respects his remarks upon
the carbonates of ammonia are original and important. Under its
medicinal uses he says that thirty grains of carbonate of ammonia
are emetic, which is far from being always the case.

The College continue to apply the erroneous terms Subcarbonate
and Carbonate of potass to the carbonate and bi-carbonate, but the
process for obtaining the latter is materially improved by deriving the
carbonic acid from carbonate of lime, instead of (as formerly) car-
bonate of ammonia. But, as if some fatality attended the intro-
duction of an innovation, they direct the gas to be passed into their
own liquor potasse, instead of a much more dilute solution, which
ought to have been employed. Mr. P. objects, we think without
reason, to the use of dilute sulphuric acid for the decomposition of
the powdered marble, and recommends muriatic acid as a substitute,
suggesting that, for sake of economy, the muriate of lime may
be decomposed by sulphuric acid, and thus dilute muriatic acid
regained; but we have not found his objections to sulphuric acid
hold good in practice.

The remaining salts of potash require little notice ; the super-

New London Pharmacopaia. 355

sulphate, perfectly useless, is still retained ; and of he hydriodate,
of which many practitioners think very highly, not a word is said.

In respect to the salts of soda we observe the same impropriety
of nomenclature in distinguishing the carbonates which has been
noticed of the carbonates of potash. The sod@ carbonas is however,
as it commonly o¢curs, a compound of an atom of carbonate and
one of bi-carbonate, with four of water, and therefore may be called
a Sesqui-carbonate of Soda. Mr. Phillips found the native carbo-
nate of soda from Africa to be an analogous compound. The fore
mula for sulphate of soda is quite unnecessary, as it is always pre
pared by the wholesale manufacturer. (

Among the earths we observe that lime is directed to be obtained
by the calcination of marble, and of shells, the use of the latter
being by no means obvious; and although marble duly heated fur-
nishes very good lime, that which may be had wholesale is as fit for
the preparation of lime-water.

Proceeding to the metals and their salts, we have to congratulate
the College upon the improvement in their formula for that most
important compound tartarized antimony, which is now prepared by
boiling finely-levigated glass of antimony with tartar in a due pro-
portion of water. The exact composition of emetic tartar is not
very easily determined, nor has our author given us any thing ori«
ginal respecting it. The hydro-sulphuretted oxide of antimony is
still retained under the improper title of Precipitated Sulphuret of
Antimony ; and the very uncertain formula for the preparation of
antimonial powder remains nearly as it was.

The more we consider the antimonial remedies of the Pharma
copia, the more we are convinced that emetic tartar is the only
certain and definite remedy of that class; that it may be used in
various mixtures as a substitute for the other preparations, and that
it is the only compound of the metal which ought to be retained in
a pharmacopeia compiled upon sound principles.

The exceeding absurdity of calling certain solutions wines which
contain no wine, occurs first under this head, where 20 grains of
tartarized antimony dissolved in 8 ounces of water, and 2 ounces of
rectified spirit, is foolishly termed Vinum Antimonii tartarzati. We
are not generally inclined to be very sceptical upon the subject of
pharmaceutical nomenclature, but this capricious innovation we
cannot leave unnoticed. In the last Pharmacopaia the term liquor
was learnedly applied toa real vinous solution ; and now, the term
vinum is applied to that which contains no wine. But the alteration
is otherwise mischievous. Antimonial wine and steel wine are do-
mestic remedies, with which every body is acquainted, and no
vender of medicines who wished to retain his customer would think
of sending out the wines of the present Pharmacopeia under that
name. ‘The apothecary therefore is obliged to hamper his shelves
with both solutions, and this merely to gratify a whimsical propen~

356 Analysis of Scientific Books.

sity for something new, which exists somewhere in the College ; for
after all, the present wines, which contain no wine, are as ob-
jectionable as the former wines which do contain it. But the
authors of the Pharmacopeia will probably tell us that it is com-
piled exclusively for their own use and convenience; that they
have nothing to do with the vulgar public; and hat if other people
are unlearned enough to call things by their proper names, they
regret their want of taste. ‘* We have thought it better,” it is
said in the Preface to the Pharmacopeia, “to risk the accusation
of barbarism than to admit terms of doubtful or uncertain significa-
tion,” but in the cases before us certainty might have been attained
without barbarism. “tn

It is with unfeigned regret, that we find ArsENtc is still retained in
the Pharmacopeia. We do not mean to say that it is useless as a
medicine, but we do mean explicitly to assert that the mischief of
retaining it is many thousand times greater than any benefit that in
any possible case can be derived from its curative powers. The
only plausible excuse for the sale of arsenic is its supposed use in
medicine ; and as long as the College think it right to sanction its
employment, so long may any person obtain it of any chemist,
druggist, or apothecary—let it be struck out of the Pharmaco-
peia, and its sale prohibited, and the numerous cases of accidental
and intentional. poisonings with it would, at all events, be thrown off
the shoulders that now alone must bear the responsibility. As to
the cow-doctors and horse-leeches, (who by the way kill more cattle
than they cure with their arsenical lotions,) we put them out of
the question—and why then is arsenic, in every way the most dan-
gerous, pernicious, portable, and certain of the poisons, the most
easy of administration, and the most difficult of detection, suffered
to be sold at every chandler’s shop in the kingdom?

The College have given sub-nitrate of bismuth a place in their new
Pharmacopeia—to this we haye no objection, though we find upon
inquiry that the physicians of most practice never prescribe it:
we must repeat that sulphate of quinine and hydriodate of potassa
should not haye been neglected, for they, and especially the former,
are in daily use.

Among the preparations of iron we, in the first place, observe
that Ferrum Ammoniatum and Liquor ferri Alcalini, useless, uncer-
tain, and unchemical as they are, are retained; this is a pity, for
all these pharmaceutical incumbrances are, in more ways than one,
prejudicial ; the advantages of tartarized iron are frustrated by the
directions for drying it; and our old acquaintance steel wine, the
vinum ferri, has a most clumsy and inefficient substitute in a solu-
tion of tartarized iron in proof spirit. Mr. Phillips is more tem-
perate in his remarks upon this preposterous innovation (which
has already excited infinite dismay and perplexity in many nurseries)
than we feel inclined to be, and we shall therefore quote his

New London Pharmacopeia. 357

most merciful criticism, observing by the way, that in compound-
ing their wines the College seem to have had an inverse eye upon
Mrs. Glass’s water pudding, so called, as she facetiously tells us,
because made with wine only.

“« This preparation,” says Mr. Phillips, “ is tartrate of potash
and iror, with excess of supertartrate of potash, which is probably
intended to supply the place of the acid contained in the wine for-
merly employed, and to effect the perfect solution of tartarized iron
in the weak spirit.

“The quantity of iron directed to be used is very nearly such, that
if it were all acted upon by the supertartrate of potash, and dis-
solved by the spirit, the strength of the present preparation would
almost exactly equal that which I found the former to possess. But
three causes prevent this: first, the whole of the iron is not acted
upon by the tartar; secondly, a part of that which is converted into
tartarized iron, is rendered insoluble by drying; and thirdly a
portion which is dissolved by the water is immediately precipitated
by the spirit. I find that owing to these circumstances, a pint of the
present vinum ferri contains only sixteen grains of peroxide, instead
of twenty-two grains, which an equal quantity of the former pre-
paration held in solution.”

Among the preparations of mercury we think that the red oxide,
the grey oxide, and the sulphurets, might without much inconve-=
nience to any one have been omitted. The formula for calomel is
most unequivocally improved ; it is, indeed, the best extant; that for
corrosive sublimate would be the better for a little alteration in the
proportion of the materials. The solution of corrosive sublimate is
here called Ziquor and not vinum, as is the case with that of emetic
tartar ; but it should not have been among the formule, for it is
liable to decompose, and in remedies of such activity every thing
depends upon the accuracy of the proportion held in solution. We
wish the College had been prevailed upon to reject their present
names for calomel and corrosive sublimate; and that Mr. Phillips
had not added to the proper chloridic explanation of their composi-
tion and formation, the incorrect and exterminated muriatic hypo-
thesis; he seems to have done it out of compliment to the College,
“« who,” he says, ‘* do not appearto have adopted the modern views
of the nature of muriatic acid ;’’ but no authority can justify the
perpetuation of error.

The preparations of lead remain much as in the former Pharma~
copwia, excepting that the term sub-carbonate is now improperly
used for what before was properly called carbonate. The formula
for acetate of lead is now no longer necessary; it is prepared of
great purity, and ata low price by the wholesale manufacturer, and
might therefore have been transferred to the Materia Medica. _

The formula for oxide zinc is much ameliorated by substituting
precipitation of the sulphate by ammonia, for the old process of com=

358 Analysis of Scientific Books,

bustion; in this way it is obtained free from metallic particles. By
some oversight the quantity of water directed for the solution of the
sulphate is however too small.

Of the preparations of sulphur, the solution of that snbstance
in oil, and the * precipitated sulphur,” might be dispensed with.

The general directions given in the Pharmacopeia for the collec-
tion, preservation, and preparation of vegetables, are meagre and un=
satisfactory ; Mr. Phillips has merely transcribed them without any
remarks. Among the distilled waters, we observe that cinnamons
water, peppermint-water, miut-water, and penny-royal-water, are
directed to be distilled either from the herbs, or from their essential
oils. The same rule should have been extended to rose=water,
which is more fragrant and less apt to acidify when so prepared.

With very few exceptions, we think that the infusions and decoc-
tions should have been left to extemporaneous prescriptions, espe=
cially the former; there are also many among them which cer=
tainly might have been altogether expunged. The extracts are also
much too numerous; they are generally apt to spoil by keeping, and
such only, therefore, should have been retained as are really useful.
Under the term eatractum stramoni we have an useless extract of the
seeds of the thorn-apple. i

Among the mixtures and spirits we also have several useless, or,
at least, unnecessary formule; among the latter, especially, spiritus
ammonie fetidus, spiritus ammoni@ succinatus, spiritus armoracie@
compositus, spiritus colchici ammoniatus, spiritus menthe viridis, spi-
ritus pimente, &c. &c., are mere incumbrances; if they are medi-
cally wanted, extemporaneous prescriptions with the essential oils
are preferable. The “ tinctures” offer a sufficiently judicious se=
lection, but many of them might be improved by digestion for a
shorter time, in a moderate heat; nothing is said of the temperature
at which they should be prepared.

Under the “ preparations of ether” we may remark, that the
formulee for sulphuric ether and rectified ether should have been
given under one head; for what is rectified sether but sulphuric
ether ? or, what medical use can be made of the impure ether
which the College call ether sulphuricus? ‘They certainly direct
it, but probably by mistake, in their spirit and compound spirit of
sulphuric ether. thereal vil, aromatic spirit of ether, and com-
pound spirit of sulphuric ether, as now directed by the College, are
very useless supernumeraries upon this list.

The Section on Athereal Preparations is followed by one including
the wines containing no wine; and then follow the medicated vine-
gars, honeys, syrups, and confections.

Among the compound powders we observe many, and among the
pills more formule, which might be dispensed with; the latier are
liable to harden, and with few exceptions should never be kept
ready made,

New London Pharmacopeia. 359

_ Under the remaining heads of the Pharmacopeia, including plasters,
ointments, &c., we observe nothing worthy of particular remark. Mr,
Phillips has added to his translation a series of woodcuts, exhibiting
the must commonly occurring crystalline furms of the principal salts,
&c., which, as far as they go, are useful, as being more explanatory
than mere descriptions, and the pupil ought, for several reasons, to
be acquainted with the ordinary figures which these bodies exhibit ;
but, as before observed, the measurements of angles and inclinations of
surfaces which accompany the description of the salts are not, we con=
ceive, very important to the utility of a work like this. We are also
somewhat disappointed at the brevity of the original remarks and scan-
tiness of the criticisms, where there is so much room and opportunity
for both, and more especially when we advert to the diligence and acu-
men, sometimes perhaps a little too highly seasoned, with which our
author animadverted upon the glaring errors and abundant inconsis-
tencies of the former Pharmacopeia. Something more also might
have been said of the medical uses and forms of prescribing the lead-
ing articles; indeed we doubt whether the present extremely concise
notices culled chiefly from Dr. Paris’s Pharmacologia, had not better
have been omitted. But we must not complain: these things are not
in Mr, Phillips’s way, and upon the whole we are indebted to him for
many useful hints and pertinent remarks.

We wish,.in conclusion, to disclaim the remotest intention of dis-
respect towards the College in any of the remarks which we have
found it necessary to offer upon their Pharmacopeia, and which, with
all its imperfections, we have already acknowledged among the best
extant. There seems, therefore, to be some hidden impediment
to the compilation of a rational Pharmacopeeia, and at all events it
must not be assumed as a standard of the talents of its nominal edi-
tors; there must be something radically wrong in the mode of mas
naging the matter, and before the College give us another edition, we
trust they will seriously consider the subject, and adopt some less
exceptionable mode of proceeding. We apprehend that the whole
business should be unconditionally delegated to three or five indi-
viduals, who should alone have power, and be solely responsible:
they should moreover be well paid for their trouble, and no expense
should be spared in furnishing them means of information and research.
The Committee which determines by vote what formule are to exist
and what to be expunged, should certainly be broken up: the men
of practical eminence in the College have no time to attend to it; and
the mcn of science are, if we mistake not, wearied out by the perse-
vering prosers and obstinate ancients with which all such Committees
are pestered,

360

Art. XIV. MISCELLANEOUS INTELLIGENCE.

1. MecHANICAL AND GENERAL SCIENCE.

1. Adhesion of Nails i in Wood.—Mr. Bevan has published in the
Philosophical Magazine a series of very interesting experiments on
the adhesion of nals when driven into different kinds of wood, the
results of which we have abstracted and condensed as below, The
following table exhibits the relative adhesion of nails of various
kinds, when forced into dry Christiana deal at right angles to the
grain of the wood:

Number to the inches _inches forced Ibs, required
Ib. avoirdupois. long. into the wood. to extract.

Fine sprigs . . . 4,560. .0.44. .040. . 22
Ditlois 0 ie By 9S} {OOK , 1OVES! 3" OAS 2 eae
Threepenny brads . 618 . . 1.25. . 0.50. . 58
Cast-iron nails) . . 380. . 1.00. .050. . 72
Sixpenny nails . . 73. . 2.50. . 100. 187
Ditto Hee he Ss ve Penge tenets ie EOL Semaey
Dittorrey teetewten eit radii wit. donee SO Ol yee
Fivepenny nails . . 139. . 2.000. . 1.50. 320

The percussive. force required to drive the common sixpenny nail
to the depth of 14 inch into dry Christiana deal with an iron weight
of 6,275 lbs. was ipa blows falling freely the space of 12 inches,
and the steady pressure required to produce the same effect was
400 lbs.

A sixpenny nail driven one inch across the grain into dry elm
required $27 lbs. to extract it; driven end-ways, or longitudinally,
it required 257 lbs, for its extraction: driven end-ways two inches
into Christiana deal it was drawn by a force of 257 lbs., but driven
in one inch only in the same direction, it was extracted by 87 lbs.
The relative adhesion therefore, when driven transversely or longitu-
dinally, is as 100 to 78, or about 4 to 3, in dry elm; and as 100
to 46, or as 2 to 1, in foe

To extract a common sixpenny nail from a depth of one inch
out of dry oak required . P ‘ : . 507 lbs.

dry beech ” ‘ A . P santaOZ

green sycamore . : 312
a common screw of + of an inch diameter was found to have an
adhesion about three times that of a sixpenny nail.—The resistance
to entrance of a nail was found to be to that of extraction, in some
experiments, as 6 to 5.—Phil. Mag. \xili, 168,

Mechanical and General Science. 361

2. Levels in London above the highest Water-mark.

eet. inches.

North-end of Northumberland-street, Strand . 19 74

North of Wellington-street, Strand . 5 a 1 Shs 6
North of Essex-street, Strand : ° ZTE
West of Coventry-street . ‘ : : - 52 0
South of St. James’s-street . F . . 13. 3
South of Air-street, Piccadilly . . . 49:8
North of St. James’s-street . . .« . 46 7
West of Gerrard-street . . . e 61 4
North of Drury-lane~ . : : : Pe NE
South of Berner’s-street : . . - 74 3
South of Stratford-place . : : . » 59 A
North of Regent-street : : = . 76 0
South of Orchard-street . ‘ ; : - 70 A
North of Cleveland-street . bp wets : 80 10
Centre of Regent’s Circus " . ant 77.02
North of Gloucester-place . 5 ~ mys a ORES
North-side of Aqueduct crossing Regent’s Canal 102 6

Opposite south-end of King-street, Great George-st. 5 6
The whole of Westminster, except the Abbey and part of Horse-
ferry-road, is below the level of the highest tide.
N. M. Mag. xii. 206.

3. On the comparative Advantage of Coke and Wood as Fuel.
Some trials have been made by M. Debret on the heating power of
coke and wood, when consumed in stoves, at the Royal Academy
of Music. Two similar stoves were heated, one by wood and the
other by coke, and the temperature of the exterior, taken at some
distance from the fire. The temperature of the flues was at first
9° c., and the mean temperature, at the end of six hours, was, by
the wood, 13° c., by the coke, 16° c.; so that the increase by the
wood was 4°, by the coke 7°. These effects were produced by se-
venty-three kilogrammes, (103 pounds) of wood, worth three and a
half francs, and twenty-four kilogrammes, (53 pounds) of coke,
worth one franc eighty cent.

During the progress of this experiment another stove had been
heated for several hours with wood, and the temperature had not
risen above 13°, ‘The use of coke very quickly raised it to 15° or
‘16°. Hence it is concluded, and with reason, that coke is. much
preferable for these purposes to wood; but where thie stove is
small the mixture of a little wood with the coke is recommended to
facilitate the combustion. —Bzb. Univ. xxv. 237.

4. Vicat on burning of Limestone or Chalk.—¥rom some experi-
ments formerly made by M. Vicat, that philosopher was induced to
conceive, that probably an imperfect calcination of limestone would

362 Miscellaneous Intelligence.

make it yield a better hydraulic lime than a more complete burning;
but having,. by the lapse of time, had occasion to make further ob-
servations on the specimens of chalk mortar, which formed the sub-
ject of the experiments on which that opinion was founded, he has
taken the opportunity of guarding against any such conclusion being
drawn from his previous statement.-—(See vol. xvi. p. 386.)

On examination of the specimens of chalk cement, four months.
after they were immersed in the water, they were found just in the
state they were in on the twelfth day; they resisted the trial needle
to a certain extent only, and not at all like a specimen of good
hydraulic lime, which was put into water at the same time.

M. Vicat had occasion to make further remarks on the imperfect
burning of lime, in consequence of the opportunity afforded by a
large block of limestone which had been used in the construction of a
kiln, and which furnished from different parts various specimens
burnt in different degrees. Five varieties were selected, No. 5, and
also No. 4, slacked in water, and were therefore set aside as consi-
derably burnt. Nos. 3, 2, and 1-were not attacked by water, they
were almost as hard as before burning, and being pulverized, sifted,
and made into a paste, they were immediately immersed in water
and left. After a month they were scarcely hardened, and were far
worse than the specimens of chalk before referred to. ‘The same
stone pulverized and calcined for twenty minutes on a red hot iron,
gave a cement not so good as the chalk, but better than the specimen
from the furnace.

‘* These experiments,” says M. Vicat, ‘¢ are far from confirming
the general results announced by M. Minard, (vol. xvi. p. 387); I
can scarcely believe that we shall ever obtain, I will not say good,
but even passable, cement, by the calcination, more or less com-
plete, of pure calcareous stones. We must probably always have
recourse to the argillaceous limestones, and when these are well
studied and classed in proportion to the quantity of clay and lime
which they contain, and that accounts are preserved in all cases of
the results of the experiments, we shall perhaps be forced to acknow=
ledge, that nothing is more advantageous than a good hydraulic
lime, which yielding from 1.1 to 1.3 parts for 1, can for 100
measured parts receive 160 or 180 of sand, and thus furnish at a
very moderate price a mortar equally capable of resisting the vicissi-
tudes of the atmosphere, and the destructive effects of running
water.—Ann. de Chim. xxv. 60.

5. On the Application of Muriate of Lime as a Manure—M. Du-
buc, a druggist, and member of the Academy of Sciences at Rouen,
has, during the years 1820, 21, 22, and 23, made use of chloride
of calcium as a manure, or according to his own expression, as a
vegetable stimulant, His experiments have been numerous, and the
following short notice is given of them by M. Lemaire Lisancourt.

Mechanical and General Sotence. 363

A kilogramme (2.2 Ib.) of chloride of calcium is dissolved in sixty
litres (126.8 pints,) of water. The ground intended for experi-
ments is watered with the solution; the seeds are then sown, or the
plants set in the ground, and ultimately the watering is repeated a
third or fourth time.with the solution.

M. Dubuc sowed some Indian corn in a light soil, watered six or
eight days before with the solution, Ata distance of six feet, but in
the same soil, and with the same aspect other maize was sown and
watered with common water. The first, which was watered from time
to time with the solution of the chloride, attained to double the size
of the second. Specimens of both were presented to the academy at
Rouen. He has also hastened and favoured the developement of the
great pyramidal campanula, of the lilac, and other trees, and also
of fruit-trees, §c. He has also made experiments on market vege=
tables ; onions, and poppies, which grow to a large size in the soil of
Rouen, have doubled in volume by the action of the chloride, He
has observed the great annual sunflower rise as in Spain to a height of
twelve or fifteen feet, whilst in ordinary circumstances this large herb
did not rise more than six or eight feet. He has seen the stems of
these vegetables three or four inches in diameter above the earth, the
leaves from eighteen to twenty inches long, the discs of the flowers
twelve or fourteen inches in diameter, producing seeds from which
haif their weight of good oil has been extracted, and ultimately ex-
uding from their centres a transparent secretion analogous to turpen-~
tine, very odorous, and easily drying in the air.

Finally, M. Dubuc made his experiments on potatoes, taking such
as in size and weight were nearly alike. These were planted May 1,
1822, in the same soil, and with the same aspect but in two beds,
separated from each other by a path six feet wide. One of these beds
was watered with the vegetative liquor, the other with water from a
cistern, They were all gathered the 10th Nov. 1822. The first
gave tubercles six inches long, twelve inches in circumference, and
weighing nearly 2lbs. each ; the others were generally about half that
size. These large potatoes were equally nourishing with the ordi~
nary potatoes, and were equally well preserved until the following
April. They were watered only three times with the solution during
the time they were in the earth, and their leaves were developed in an
equal proportion. '

It appears that in general it is sufficient to water the vegetables
submitted to the action of chloride of calcium three or four times with
the solution at long intervals. The electro-organic power of this
substance seems very singular, for, as M. Labarraque, of Paris, has
observed, when applied to the animal organization, it in a short time
arrests the progress of gangrene, chancres, or ulcers, and powerfully
favours the production of fleshy pimples, which cicatrize the sore, —
Ann. de Chim, xxv, 214.

364 Miscellaneous Intelligence.

6. Preparation of Caoutchouc.—Mr. T. Hancock, has succeeded,
by some process, the results of long investigation, but which he
has not published, in working caoutchouc with great facility and
readiness. It is cast, as we understand, into large ingots, or cakes,
and being cut with a wet knife into leaves or sheets about 3 or +4; of
an inch in thickness can then be applied to almost any purpose for
which the properties of the material render it fit. The caoutchouc
thus prepared is more flexible and adhesive than that which is gene-
rally found in the shops, and is worked with singular facility. Re-
cent sections made with a sharp knife or scissors, when brought to-
gether and pressed, adhere so firmly as to resist rupture as strongly
as any other part, so that iftwo sheets be laid together and cut round,
the mere act of cutting joins the edges, and a little pressure on them
makes a perfect bag of one piece of substance. ‘The adhesion of the
substance in those parts where it is not required is entirely prevented
by rubbing them with a little flour or other substance in fine powder.
In this way flexible tube catheters, §c., are prepared ; the tubes being
intended for experiments on gases, and where occasion might require
they should sustain considerable internal pressure, are made double,
and have a piece of twine twisted spirally round between the two.
This therefore is imbedded in the caoutchouc, and at the same time
that it allows of any extension in length of the tube, prevents its ex-
panding laterally.

The caoutchouc, is in this state, exceedingly elastic. Bags made of
it as before described, have been expanded by having air forced into
them until the caoutchouc was quite transparent, and when expanded
by hydrogen they were so light as to form balloons with considerable
ascending power, but the hydrogen gradually escaped, perhaps
through the pores of this thin film of caoutchouc. On expanding
the bags in this way the junctions yielded like the other parts, and
ultimately almost disappeared.

When cut thin, or when extended, this substance forms excellent
washers, or collars for stop-cocks, very little pressure being sufficient
to render them perfectly tight. Leather has also been coated on one
surface with the caoutchouc, and without being at all adhesive, or
having any particular odour, is perfectly water tight.

Before caoutchouc was thus worked it was often observed how
many uses it might in such a case be applied to; now that it is so
worked it is surprising how few the cases are in which persons are
induced to use it. Even for bougies and catheters it does not come
into use, although one would suppose that the material was eminently
fitted for the construction of these instruments.

7. Magnetic Intensity of a Chronometer——A remarkable example
of the magnetic intensity of a chronometer has just appeared in
Vol. X., PartI., of the Transactions of the Royal Society of Edin-
burgh. Mr, Harvey, the author of the investigation, by employing

Mechanical and General Science. 365

a very delicate apparatus, constructed on the principle of Coulomb,
and capable of detecting the minutest traces of attraction, disco-
vered very remarkable varieties of magnetic power in a time-keeper.
By denoting the intensity of the terrestrial magnestism by 100, he
found the intensity of the chronometer one inch above the centre of
its crystal, to be respectively 90.79, 102.29, 90.69, and 78.89, ac-
cording as XII was directed*north, east, south, and west. By deter-
mining also the tntensity one inch below the bottom of the time-
keeper, the intensities in the same directions were 77.17, 91.34,
101.26, and 94.94. In like manner Mr. Harvey found, by deter-
mining the intensities of the sides, that they were severally 105.61,
89.61, 91.78, and 84.05. The intensity also one inch above the
extremity of the steel arbour of the fusee was 109.09; and in the
line of a common tangent, proceeding from between the barrel
and fusee, XII being uppermost, 107.82. When, however, the
chronometer was turned a quadrant, so as to bring the middle of the
side of the spring-box an inch below the centre of the oscillating
bar, IX being uppermost, the intensity amounted only to 92.223
and over the small interval between the balance and. the fusee,
it fellto 79.51.

On examining the balance Mr. Harvey found the inner rims of
the arcs of compensation to be of steel, and which, together with
the time-screws, were in a state of active magnetism, particularly
the latter, one having strong northern polarity, and the other
southern. The small wormed cylinders also, on which the ther-
mometer pieces moved, presented equal proofs of polarity, one
being a north pole, and the other a south. When the north pole of
a small bar magnet was placed near the extremity of the wormed
cylinder which possessed northern polarity, the balance immediately
receded a smal] quantity ; but when the south pole was applied, the
power was sufficient to cause it to advance through a minute but
sensible arc; and similar effects were produced when the proper
poles of the magnet were presented to the extremity of the wormed
cylinder having southern polarity. On presenting a more powerful
magnet, the balance was drawn more than a quadrant from its
quiescent position, and motion communicated to the chronometer.

The effect of the balance on a pocket compass was observed in
another experiment; and a table is given in the paper, illustrating
the deviations produced in it, by moving the balance through given
ares. An arc of 110° produced a deviation of 544°. A compass
needle of a more delicate construction was inverted, the moment the
time-screws had passed through an arc of 90°. A curious effect
was also remarked by Mr. Harvey, by turning the balance through
a greater arc than a quadrant, and thereby causing the north pole of
the compass to point west, when, by allowing the balance to oscil-

late, the compass needle ranged for many seconds through the com-
Vou. XVII, ; 2C

366 Miscellaneous Intelligence.

plete circumference, until the directive power of the earth, by
gaining the ascendancy, caused the arcs of vibration successively to
diminish ; the needle ultimately obtaining a position coincident with
the meridian, where it continued in a state of tremulous motion as
before.

Mr. Harvey remarks, that the quantity of steel contained in the
chronometer was truly remarkable, and no part of it was destitute
of vigorous polarity. Every screw displayed its influence, and of
which there were ten large, and several small ones, in the frame
alone. The chain also, the axles of the different wheels and pinions,
the arbor of the fusee, the balance and its spring, exhibited the same
intense and active power. Nor did this polarity partake of the
transient character of that imparted by induction from the earth to
soft iron, but was permanent, undergoing no sensible alteration frem
change of position.

‘ 8. Influence of Magnetism on the Rates of Chronometers.—This
interesting and curious subject continues to interest philosophers, and
Mr. Harvey, in the XIXth and XXth Numbers of the Edinburgh
Philosophical Journal, has two papers, devoted to the consideration
of the changes which time-keepers undergo, altering their positions
with respect to the attracting force,

A pocket chronometer, having a very steady and uniform rate of
+20".4, was placed with its main spring nearly in contact with the
magnet, and with the magnetic power directed through its centre,
when the rate altered to +65".1; but on moving the centre of the
main spring 90° from the preceding position, so as to cause the mag-
netic power to be transmitted through the centre of the balance, the
rate immediately declined to —23'.2; and on turning the time-
keeper another quadrant, so as to remove the centre of the main-
spring 180° degrees from its first situation, the rate again rose to
+43".4; and when through another quadrant, the attractive force
being in this situation transmitted nearly through the centre of the
balance, the rate became —2".6 ; and on restoring it to its first posi-
tion +72".7. When the time-keeper was detached, its rate returned
to +18”.2. Similar experiments with another chronometer, having
a detached rate of —2’.0, produced in situations corresponding to
the last, the rates +10”.0, +31; -+5”.0, and —1".1. From
these experiments, Mr. Harvey deduces, that an increase of rate
resulted from the direct transmission of the magnetic influence through
the centre of the main spring ; and a diminution thereof, when the same
power passed nearly through the middle of the balance and its spring.

Mr Harvey has, however, not only determined the effect of the
direct transmission of the magnetic power, through the centre of the
main-spring, but also that produced by its partial operation. For
this purpose, the first of the before-mentioned chronometers was so

Mechanical and General Science. 367

placed, that a radial line proceeding from the centre of the time=
keeper through the middle of the main-spring, might form an angle |
of 27° with the longitudinal axis of the magnet. The consequence

of this application was an immediate increase of +20".1, its de-

tached rate, to +52".3 ; a quantity /ess than the mean of the two re-

sults obtained from the direct transmission of the magnetic power

through the centre of the spring, by +16".6. By pursuing this

branch of the subject, the author of the experiments found, that the

removal of the centre of the spring from the axis of the magnet,

through equal arcs, appeared to produce proportional declensions of
rate. In one experiment, the rates +68."9 and +43."4, pro-

duced by the direct transmission of the attractive force through the

eentre of the main-spring, and when this point was at its least and

greatest distance from the pole of the magnet, are very nearly pro-

portional to +50’.8, and +-33’.7, the rates obtained, when the ra-
dial line proceeding from the centre of the time-keeper through the
middle of the main-spring, formed respectively angles of 27° and

153°,

An exception to the above conclusions was discovered by Mr.
Harvey, when experimenting with ancther chronometer, the accele-
rations in the rate having taken place when the’ magnetic power was
transmitted through the centre of the balance; and the retardations,
when it passed through the middle of the main-spring ; and the
author, when alluding to this anomalous result, properly observes,
in the pursuit of experimental science, every result ought to be
fairly and impartially recorded. The admirable maxim of Bacon,
we cannot control Nature, uniess by making her manifest, should ever
be present to the mind of the inquirer.

The influence also of magnetized plates is illustrated by several
experiments. ‘Iwo chronometers, when placed on a circular mag-
netic plate, Jost by having XII turned from N. to E.; gained by
being turned from EK. to S.; dost from S.to W.; and gained from
W. to N.; the changes from plus to minus being alternate. It was
found also, that the difference even of one-eighth of an inch, in the
position of the chronometer on the magnetized plate, was constantly
accompanied by a sensible alteration of rate. The rate was always
augmented by moving it nearer to the north pole; and the most con-
siderable alterations were found in the east and west positions of the
time-keeper, whien the line drawn from the axis of the chronometer
to the centre of the balance, was at right angles to the meridian of
the magnetized plate. ‘Ihe smallest changes were also produced in
those situations of the chronometer corresponding to north and south,
the centre of the balance being in those positions of the machine, in’
the magnetic axis of the plate.

9. On the Adaptation of a Compound Microscope, to act as a Dyna-
meter for Telescopes. By C. R. Goring, M.D,.—It appears to me
2C2

368 Miscellaneous Intelligence.

that at this moment asimple, cheap, and accurate dynameter, is ra-
ther a desideratumm ; the best, 1 believe, now in use is that invented by
the late ingenious Ramsden, whose ruling passion seems to have
been not only to surmount difficulties, but to create them also in
many instances. He seems to have selected one of the most com-
plicated and difficult principles to carry into effect on which a dyna-
meter can be formed; and however excellent it may be in itself, very
few workmen of the present day will undertake to execute dyname-
ters of his construction. In consequence the most common instru-
ment of the kind is nothing more than a mother-of-pearl micro-
meter, with divisions of an inch into 200 parts, attached to a lens.
This again is too coarse an instrument, and is, moreover, very difficult
to use, having no contrivance to adjust it to perfect vision on the
pencil of light, in addition to which it frequently cannot be adapted
to measure high powers at all, from an impossibility of getting it
close enough to the eye-picce, the brass work of which will not per-
mit the plate of the micrometer to arrive at the point on which a
very short pencil of rays falls. ‘To obviate all these inconveniences,
nothing more would be necessary than to use a compound micro-
scope, having the micrometer at its field-bar, in the focus of the
eye-glass. It will be very easy to shew that this sort of dynameter
will be perfectly commodious, not liable to get out of order, and
susceptible of any degree of accuracy which we may think it neces-
sary to obtain; I am only surprised that it is not to be found in all
the opticians’ shops.

Let us suppose the object-glass of such a microscope to be 4 inch
focus, that the eye-glass is 1 inch focus, with a negative field-glass,
and that there is a micrometer of mother-of-pearl at the field-bar
having divisions to the =45 of an inch, (which I know by experi-
ence can be read with a lens of 1 inch focus).—According to the
length of the tube of the microscope the image at the field-bar will
be more or less magnified,—say it is 7 times larger than the object—
then a pencil of rays of =$5 of an inch diameter will subtend 75
on the micrometer, and may be seen divided into 7 parts, therefore
it may be measured to the 3555 of an inch, a degree of accuracy
quite sufficient, I apprehend, for practical purposes—if not, we have
only to increase the depth of the object-glass, and we may obtain a
scale to any extent we please. In the same manner, if the divisions
of the micrometer are not seen with sufficient ease, the depth of the
eye-glass may be augmented. Were it an object to carry this prin-
ciple to its utmost extent, onc of Mr, Troughton’s micrometers might
be attached to the body of the microscope; but this | apprehend
would be quite superfluous.

One circumstance in constructing this dynameter must be strictly
attended to; I mean the ascertainment of the exact value of the di-
visions of the mother-of-pearl, which is done with perfect facility
by viewing another similar micrometer placed in the focus of the

Mechanical and General Science. 369

J

object-glass ; and by shortening or lengthening the tube of the mi-
croscope, the divisions may be made to coincide in any point which
is selected. J think it will be found convenient to have the micro-
meter in the field-bar on a narrow slip of mother-of-pearl divided into
100 parts to one inch, and then again into 5 more, and to adjust the eye-
glasses and the length of the tube so that 1, of an inch in the focus
of the object-glass shall be equal to 1 inch at the field-bar, and so to
fill the whole of the field of view. It would perhaps facilitate the
reading of the divisions if a dot were placed at every tenth of an inch
on the micrometer.

With respect to mechanical arrangements, the body of the dy-
nameter should be made to slide up and down in another tube with
or without rack work, which may be pressed firm by the hand
against the eye-piece of the telescope, whose powers it is applied to
measure ; while the internal microscope is adjusted to distinct vision,
the external tube may be casily made applicable to any telescope, or
a shoulder with a screw might be left upon every eye-piece to which
the said tube may be firmly attached. It will be evident that the
object-glass of such a dynameter will always be at an abundant
distance from the shortest pencil of rays it is employed to measure.

I should scarcely have thought it worth while to have pointed out
so obvious an application of the compound microscope, but I have
never seen or heard of its adaptation to any such purpose as I have
recommended, Jt must be recollected that some have the faculty of
perceiving things for themselves, others only when they are pointed
outto them, and many hardly then ;—of this the history of Columbus
and hisegg will remind us.

II. Cuemicat Scrence.

1. On a Reciprocity of insulating and conducting Action which the
incandescent Platina of Davy exerts on the two Electricitics.—The fol-
lowing is part of an extract communicated to the Annales de Chimie,
(xxy. 278.) from a memoir of M. Erman, inserted in the memoirs of
the Academy of Berlin, for the years 1818 and 1819.

Place on an electrometer an aphlogistic lamp, of which the upper
spirals of platina wire are in full incandescence, and hold at the
distance of four or five inches above the lamp the negative pole of a
dry voltaic pile, or the negative coating of a small Leyden jar
feebly charged, the electrometer will diverge powerfully. Present in
the same manner the positive pole or coating, there will be no diver-
gence or atleast a very slight one, and that due to induction,

Place above an insulated aphlogistic lamp, at the distance of four
or six inches, a small screen of any conducting substance, making it
communicate with an electrometer, then touch the lamp with a po-
sitive pole or coating, ad the electrometer of the screen will diverge

370 Miscellaneous Intelligence .

powerfully; but if the lamp be touched with’a negative pole or
coating, no divergence, or only a very slight one, will take place.

The following table will illustrate the difference of effect when the

lamp was postive and negative. ‘The first column is the number of
inches between the lamp and the screen above.
Lamp positive. ‘ Lamp negative.

1 inch The leaves opened to their full The leaves opened
extent (14 lines) in 1” and dis- — the 14 lines in 345”
charged themselves against the
side every second.

ost Ditto in 14" 345”
3 5 (0:98 540”
4» as leaves diverged one

line in 150° and only
diverged 24 lines on
the whole.

5", rset 1 line in 210” total
divergence 14 lines.
Gigs 39. ah! 1 line in 240” total

divergeace 1 line.

A similar, but inverted table would represent the progress of
the electrometer attached to the lamp, the screen being similarly
electrified.

There exists, therefore, incontestibly a reciprocity of conducting
and insulating actions ; the lamp conducts and transmits the positive
effect tothe screen, but not the negative ; on the contrary, the screen
transmits the negative effect to the lamp, but not the positive. This
singular property is found to exist in all the combinations of this
kind which can be imagined. ‘Thus, for example, if a Leyden jar is
moderately charged positive by its ball, and this applied to the
insulated aphlogistic lamp, a smaller Leyden jar, with its ball held
about four or six inches trom the incandescent platina, will become
very sensibly charged; but if the ball of the first be electrized ne-
gatively, there will be no charge given to the second, on iepeating
the experiment. By disposing successively a number of electro-
meters, each with its aphlogistic lamp, so as to establish a communi-
cation from one to the other, a very paradoxical system is obtained,
representing a species of pile which is rapidly traversed by positive
electricity from right to left, but not at all in the opposite direction,
whilst with negative electricity the inverse directions are equally
distinct: though as the author has not succeeded in increasing the
effect by the successive groups, it has perhaps more analogy with the
tourmaline. Electro-magnetic phenomena were not known at the
time when M. Erman discovered the reciprocity of insulating and
conducting action, and he has not as yet published the result of
his ultimate researches on the electro-magnetic effects of incandescent
platina,

Chemical Science. 371

It may, perhaps, be supposed that the effect is due to the power the
ascending current of vapours has to take positive electricity with it to
the screen above, and probably the experiment may be considered as
a proof of the truth of Franklin’s theory, and an argument against
Dufay. But it is not in a vertical direction only that the aphlogistic
lamp receives negative electricity from without, and not positive ; but
in all directions, and from all the concavity of a sphere, of which the
lamp is the centre. It is not therefore on an emanation in the
direction of the ascending current of vapours that the effect depends,
but it resembles rather a radiation like that of light and heat. Se-
condly, the reciprocal effect essentially requires the actual incan-
descence of the upper spirals of platina; without this the apparatus
may be disposed so as to emit a much larger quantity of vapours, but
in vain. Thus, for instance, 397 grains of platina, which arranged
properly on a wick would light amadou at two lines distance, and
keep 400 grains of water boiling, offered nothing like the reciprocal
action because the upper spires were not ignited ; whilst a spiral only
a few grains in weight, but incandescent to its extremity, acted in a
most decided manner. ‘Thirdly, heated iron offers some traces of this
reciprocity, but only whilst it is in full ignition. The effect cannot,
therefore, depend on a heated current, which would continue long
after ignition had ceased. M. Erman has also seen many cases in
which the iron has had the opposite power to the platina, emitting the
~ negative and receiving the positive electricity. Finally, as an argu-
ment against the efficacy of a heated current, undecomposed vapour
at a high temperature possesses no power,of conducting electricity.

Without insisting much upon it, M. Erman suggests the following
explanation of the phenomena:

There exists two electricities, between which there is a specific difler-
ence of expansibility: the heat of incandescence acts by augmenting
this expansibility, in the same manner as the pointed form of con-
ductors augments the tension, If this augmentation of expansibility
be very considerable, the specific difference of the two electricities
disappears in the greatness of the whole effect: this is the case with
flame ; but there exists a certain degree of heat which augments
the expansibility in a less degree, and precisely to the point at
which the most expansible of the two (the positive) is able to over-
come the constraining force of the circumambient medium, whilst the
less expansible (the negative) notwithstanding the increment of force
it has received, has not yet attained to the point at which it can over-
come the resistance of the medium, ‘The action of the incandescent
wire is, therefore, according to this view, connected with the pheno-
mena of the specifically different lights, presented by points positively
or negatively electrified. Sufficient examination has not been made
whether points, not incandescent, emit different quantiiies of elec-
tricity according as they are positive or negative; but the marked

372 Miscellaneous Intelligence.

effects of a pile ofa single metal, terminating at one side in a point,
and the other in a large surface, and placed end to end in water, with
merely this geometrical difference, proves evidently that something of
this kind exists, and it was whilst occupied with these piles on geo-
metrical principles that the author was conducted to researches on
incandescent points.

If the rays of the sun, by heating the soil, produce an effect ana-
logous to that spoken of, 2. €., to increase the electric repulsion, but
only in the proportion required to make the positive fluid overcome
the resistance of the air, and not the negative, it would explain the
habitually positive state of the lower strata of the atmosphere. The
author has not, however, found this idea confirmed by experiments
with the aphlogistic lamp. In fact, when left on a condenser for
several hours it had not disturbed the electrical equilibrium, 2, e., the
excess of expansibility acquired by the positive electricity was not
sufficient to detach it from its combination with the negative electricity.

2. On the Magnetic Action of strong electrical Currents on different
Bodies.—Coulomb, in 1802, gave the results of a well-known series of
experiments on the action exerted by the opposite poles of two power-
ful magnets on minute needles of any substance delicately suspended
between them. It was found that, whatever the nature of the sub-
stance, the needle ultimately arranged itself in the direction of the
poles; but he finally concluded that this was due to the minute
portions of iron which they contained.

M. Biot, who repeated these experiments very carefully, is not
entirely of this opinion; but suggests, that inasmuch as simple con- —
tact of heterogeneous bodies is sufficient to develop electrical forces,
which for a long time were quite unsuspected, perhaps other cir-
cumstances may develop similar or analogous forces extremely
feeble, but sufficient to affect apparatus delicate as Coulomb’s.

After this M. Ampere, with M. A. Delarive, made an experiment
at Geneva on the effect of electrical currents on a plate of copper,
and conceived that the copperplate, by being near the currents, was
capable of affecting the magnet like the neighbouring wires, through
which the current was passing, but afterwards ascertained that this
was not the case.

Ultimately M. Becquerel has resumed the examination of these
or similar phenomena, making use of Schweigger’s multiplier for
the concentration of the powers of the clectrical current, and he
has observed differences between the effects thus produced and those
obtained in M. Coulomb’s experiments. The galvanometer used was
1.97 inches long and about 0.4 inches wide. Care was taken that the
substances should not be worked with iron instruments, and the needles
formed of them were made very small, especially if of a substance
but feebly affected by the electrical current; they were then suspended

Chemical Science. ae’

in the galvanometer just as a magnetic needle would be, and a
Wollaston’s pile of 10 pair of plates connected with the wires of the
instrument.

A needle of soft iron instantly placed itself parallel to the axis of
the spirals, the arrangement of magnetism in it being similar to that
of a common bar magnet.

Deutoxide of iron enclosed in asmall paper cartridge 0.157 of inch
in diameter, and properly suspended, was rapidly drawn into the
plane of the apparatus, and took a position perpendicular to the axis
of the spirals; but soft iron filings similarly circumstanced acted just
like the iron needle.

The difference exhibited in this way between these two sub-
stances does not exist in Coulomb’s manner.of making the experi-
ment, and hence a difference of action would seem to be indicated
between the electro-magnetic wire and magnetic poles.

Needles of copper, wood, or gum Jac, were affected like the
deutoxide of iron, but in a smaller degree; but great caution is re-
quisite in making these experiments to avoid currents of air; this is
best done by closing the extremities of the galyanometer in glass.

Needles thus affected by the electric current were then examined
as to their action on a feeble magnet. The iron needle was found
to act like a regular magnet, and it is to be presumed that the car-
tridge of iron filings did so also ; but the parcel of deutoxide of iron,
when examined, was found to act with one pole of the bar in the
same manner at every point situated towards one side of the galvano-
meter, and inversely when the pole was changed, so that the north
Magnelism was on one side of the needle, and the south on the
other. It is, however, possible to distribute the magnetism as in the
common needle, which is done by retaining the cartridge for some
time parallel to the axis of the instrument; but when left to itself,
it returns gradually to the state described. ‘The action of the magnet
on the other needles, when in the galvanometer, gave no certain
results.

A needle of wood about 1 inch in length, and .04 of an inch
in diameter, had fixed at each extremity a square plate of steel or
soft iron .08 of an inch in the side, and .008 of an inch in thickness,
when placed in the spiral it was rapidly drawn into a position pa-
rallel to the plane of the spirals, the distribution being as in the car-
tridge of deutoxide. Two pieces of iron wire 0.04 of an inch in
length were then put in place of the plates, and now the needle
stood in the instrument at an angle of 45° with the plane of the
spirals, or with its axis; as the length of the ends of iron wire was
increased the needle tended more to parallelism with the axis,
and when these extremities were 0,4 of an inch long, the needle stood
parallel to the axis of the instrument.—Ann. de Chim. xxv. 269.

3. On Electro-motive Actions produced by the contact of Metals and

374 Miscellaneous Intelligence.

Liquids, &c., by M. Becquerel.—The apparatus used by M. Beequerel
to collect and indicate the electricity developed by the contact of a
solid with a liquid is a condensing clectroscope of extreme sen-
sibility, invented some time since by M. Bohnenberger*, but varied
and rendered more delicate for the present purpose by M. Becquerel.
The instrument of the latter philosopher consisted of a single dry
voltaic column fixed horizontally on a wooden support, and having
attached to each of its poles, in a vertical position, a plate of metal
about 3 inches long: these plates are placed near together, and a
slip of gold leaf hung between them, connected with a condensing
plate 9 inches in diameter. The sensibility of this apparatus is such
that a tube of glass rubbed on cloth acts in dry weather at a distance
of 8 or 10 feet, and the electric state of the hand or hair has an
influence at the distance of several fect. Hence the utmost precau-
tion is requisite in experimenting with the instrument.

The following are some of the experiments made with this appa- °

ratus, the gold leaf being in communication in all of them with
the lower plate of the condenser. A brass capsule containing an
alkaline solution, or ammonia, was placed on the upper plate of the
condenser: a communication was then made with the solution by
touching it with the finger, or a moistened band of cloth, and
the lower plate was also connected with the earth; a few moments
after the upper plate was raised, and the gold leaf moved towards
the positive pole; thus the alkaline solution, or ammonia, by con-
tact with the copper, had taken positive electricity, and the metal
negative electricity.

When sulphuric acid was used in place of alkali, opposite elec-
trical effects were produced, the acid became negative, and the
metal positive.

A platina capsule filled with an alkaline solution was placed on the
upper condensing plate ; the under plate was then touched on the one
hand by a plate of platina, and on the other the liquid was touched
by the finger, and in this manner the electro-motive actions of the
platina on the copper was neutralized, being the same on both sides,
and therefore the upper plate would only retain the electricity due
to the contact of the platina with the solution. Sometimes it is ne-
cessary to put a small piece of paper between the platina and the
copper, for the apparatus is so sensible, that a very small difference
in the state of the surfaces is sufficient to influence the results. Ope-
rating thus the same results were obtained as before with alkali; the
platina became negative, and with acid it became positive. A zinc
capsule filled with solution of soda became negative, and with con-
centrated sulphuric acid positive; when the acid was diluted no elec-
tricity was developed. Silver became very feebly electrical in con-
tact either with acid or alkali.

* See vol. xi. p. 208, of this Journal.

ee

Chemical Science. 375

- In general metal in contact with acid becomes positive, making
the acid negative, and with alkalies the reverse effects are obtained ;
but there are many cases, as with silver, in which the electro-
motive action can scarcely be observed.

“ Sir H. Davy had found that those acid and alkaline substances
which can exist in a dry and solid form become electrical by their
contact with metals; thus perfectly dry oxalic or succinic acid, either
in powder or mass, when placed on a copperplate, takes negative
electricity, and communicates positive electricity to the metal. The
celebrated English chemist found also, that in consequence of the
difficulty of depriving potash and soda of water, they did not in
general produce any electricity by their contact, but that after being
strongly calcined they possessed for a moment the power of be-
coming electric by contact with a metal, He endeavoured also to
determine, by means of very delicate instruments, the electric state
of an insulated acid or alkaline solution after their contact with the
metal, but there were no results of that nature.” ;

“« We have proved, therefore, that the electric effects observed by
Sir H. Davy as produced by the contact of a solid dry acid or alkali
with a metal, and where consequently there is no chemical action
extends to the contact of all the metals with acid or alkaline solu-
tions, even though sometimes chemical action may have com-
menced.”

Haying determined the electric state of an acid or alkaline solu-
tion in contact with a metal, the next object was to ascertain the
effect when the solution was placed between two different metals,
The copper capsule was placed on the upper condensing plate, and
filled with an alkaline solution or very dilute sulphuric acid; the
solution was then touched by a plate of zinc, taking care that the
two metals did not come in contact, and the lower condensing plate
was touched with the finger; twenty seconds after, on raising the
upper plate the gold leaf moved towards the positive pole, so that
the copper capsule had become positively electrified. On putting a
zinc capsule on the upper plate with one of the two solutions, touch-
ing the lower plate with a piece of zinc so as to neutralize the electro-
motive action of that metal on the copper, and touching the liquid
with a piece of copper held in the hand, an electrical state was pro-
duced, which, on raising the upper condensing plate, made the
gold leaf move towards the negative pole, consequently the zinc
capsule had become negative. Hence it is seen, that when zinc and
copper are separated by an acid or alkaline solution, the zinc becomes
negative, and the copper positive, which is the inverse of that which
takes place when the two metals are in contact.

Another result obtained experimentally by M. Becquerel is, that
copper in a solution of muriate of soda becomes negative, and the
solution positive. —Ann. de Chim. xxv. 405.

376 Miscellaneous Intelligence.

A. Measurement of the conductibility of Bodies for Electricity —M.
Rousseau has, for several years past, been occupied in the construc-
tion and observation of dry voltaic piles, and has lately applied them
to the determination of the conducting power of bodies, in regard to
electricity. MM. Ampere and Dulong were directed by the French
Academy to report on a memoire by M. Rousseau on this subject,
and the following statement is drawn up from that report. The dry
pile is formed of discs of zinc-leaf, and tinsel, separated by discs of
parchment, previously imbibed with a mixture of equal parts of oil
of poppies and oil of turpentine ; the whole pile is covered with resin

to prevent the contact of the air. The pole is fixed vertically com-.

municating below with the earth, the upper end is made to communi-
cate at pleasure by awire to a pivot, on which is placed a weakly-
magnetized steel needle, and alsoto a metallic ball placed at the same
height as the needle, and not quite half its length from the pivot ;
hence, when the communication is made the needle and ball are
similarly electrified and the needle is repelled ; and when the needle
and ball are previously placed in the magnetic meridian, the position
to which the needle is repelled is proportionate to the magnetic and
electric forces, and is constant for a very considerable time for the
same apparatus. The magnetic needle might be replaced by a simple
electric needle suspended by a wire of proper length and diameter,
forming a balance of torsion; but the arrangement of M. Rousseau
is more convenient, and sufficiently sensible.

On using the instrument, the substance of which the conductibility

is to be measured, is made part of the connexion between the top of,
the pile and the needle and ball, care being taken that the portion:

traversed by the electricity is always of the same dimensions. If the
time occupied in producing the greatest deviation is not instantaneous,
then the period which passes before the needle takes a permanent
position is a measure of the conductibility of the substance employed.

Liquids, when tried, are put into small metallic vessels communi-
cating with the ball and needle, then a wire partly covered with gum
lac, except for a certain length at the extremity, has that uncovered
portion entirely immersed in the fluid, so that the same surface is
always in contact; then, on connecting the other end of the wire with
the end of the pile, the time which passes before the needle is at its
maximum deviation is observed, and is inversely as the conducting
power of the liquid.

Observing in this manner, a remarkable fact was noticed with olive
oil, for, notwithstanding its similarity to other oils, it was found to
be exceedingly inferior in conducting power. ‘Thus all other things
being equal, olive-oil required 40’ to produce a deviation produced
in 27’ by poppy and other oils, and on adding to olive-oil only +45
of another kind of oil, the time was reduced to 10’. Hence any
adulteration of olive-oil is easily discoverable by the instrument.

Solid fat conducts with less facility than animal oils, from the ex=

SS ere

Chemical Science. 377

cess of stearine in it, for it was ascertained that elaine conducted
electricity much better than stearine. ‘The fat of an animal dimi-
nishes in conducting power with the age of the animal. ‘The same
apparatus also marks a nectable difference between resin, gum lac,
and sulphur, the most insulating of all bodies known, and also be-
tween silk, flint-glass, and common glass.

As to alcoholic or aqueous fluids, acids, alkalies, §c., the time
required was too short to be adopted as a measure, but a modification
of the apparatus would enable it to measure the conducting power of
allof them. It is remarked also in the report, that ‘* it would be
equally possible and very curious to make trial of the two electricities
on various substances, for it would be suflicient for that purpose to
put the poles of the pile alternately in communication with the earth,
Itis probable, according to the results formerly obtained by Erman,
that differences would be found with certain substances.—Ann.
de Chim. xxv. 373.

5. Distinction of Positive and Negative Electricity.—Positive and
negative electricity may be readily distinguished by the taste, on mak=
ing the electric current pass by means of a point on to the tongue.
The taste of the positive electricity is acid, that of the negative elec-
tricity is more caustic and, as it were, alkaline —Berzelius.

6. Electricity produced by Congelation of Water.—When water is
frozen rapidly in a Leyden jar, the outside coating not being insulated
the jar receives a feeble electrical charge, the inside being positive,
the outside negative. If thisice be rapidly thawed, an inverse result
is obtained, the interior becomes negative, and the outside positive.—
Grothus.

7. Hare’s Single Gold-leaf Electrometer.—This instrument consists
of a glass vessel, fixed by a foot on to a wooden stand, and haying an
aperture at the top and also another at one side. ‘The top is closed by
a metal cap, finished externally by a horizontal zinc disc, six inches
in diameter, and connected internally with a single leaf of gold cut
into an acute triangular form, and hanging in the centre of the instru-
ment with the point downward. Opposite to the lower end of this
leaf of gold is a ball attached to a horizontal wire, and which
passing through a screw cap fixed in the lateral opening of the glass
vessel, can be made to approach to, or recede from, the leaf at
pleasure, the distance being estimated by a graduation on the screw
into +4oth parts of aninch. A plate of copper six inches in dia-
meter, and furnished witha glass handle, generally accompanies the
instrument.

*« The electricity produced by the contact of copper and zinc is ren-
dered sensible in the following manner: Place the disc of copper
on the disc of zinc, take the micrometerescrew in one hand, touch

378 Miscellaneous Intelligence.

the copper disc with the other, and then lift this disc from the zinc.

As soon as the separation is effected the gold leaf will strike the ball,
usually if the one be not more than +3, of an inch apart from the
other.” “That the phenomenon arises from the dissimilarity of the
metals is easily shewn by repeating the experiment with a zine disc,

in lieu of a disc of copper. ‘The separation of the homogeneous discs.

will not be found to produce any contact betweenthe leaf and the ball.”

** Itis probable that the sensibility of this instrument is dependant
on that property of electricity which causes any surcharge of it
which may be created in a conducting surface, to seek an exit at the
most projecting termination or point connected with the surface,”
this disposition being increased of course by the proximity of the ball.
These effects are not to be expected in weather unfavourable to elec-
tricity, but in favourable circumstances they have been produced by
a smaller instrument, the discs being only two inches and a half in
diameter.

8. Hare’s V oltate Trough.—Dr. Hare states that, having had occasion
to remark the surprising increase in the deflagrating power of a series
of galvanic pairs, when, after due repose, they were simultaneously
exposed to the acid, he was induced to devise means of accomplishing
this object in various, ways, and that ultimately the following method
occurred to him as the best: Two troughs are joined lengthwise edge
to edge, so that when the sides of the one are vertical, those of the
other are horizontal. Then by a partial revolution of the two troughs,
thus united upon pivots which support them at the ends, any fluid
which may be in one trough must flow into the other, and on revers-
ing the motion, must flow back again. The galvanic series being placed
in one of the troughs, the acid in the other, by a movement such as
above described, the plates may all be instantaneously subjected to
the acid, or relieved from it.

The pivots are made of iron, coated with brass or copper, as less

liable to oxidizement ; they are connected within with the galvanic.

series, and move on pieces of shcet-copper, which are easily made
the extremities of connecting pieces, and thus the whole can be ar-
ranged in any way found convenient.

9. Dobereiner’s Instantaneous Light Apparatus.—Since the very
curious observation made by M. Doberciner of the power possessed
by spongy platina of determining the combination of oxygen and hy-
drogen at common temperature, that substance has been applied,
among other uses, to the construction of an instantaneous light ap-=
paratus; a jet of hydrogen is thrown on to a portion of the spongy
platinum, and is by it inflamed. Various modes of presenting the
plantinum to the hydrogen have been devised, but none surpass or
even equal that originally adopted by M. Dobereiner. The extre-
mity of a fine platina wire is to be rolled into a spiral form, and then

Chemical Science. 379

dipped into ammonio-muriate, or muriate of platina, until about two
grains are taken up, after which it is to be heated red-hot in a spirit
lamp. In this way a quantity of spongy platina is formed on the
wire so minute, that if put into contact with a mixture of oxygen
and hydrogen it becomes heated, and inflames the gas as rapidly
almost as if an electrical spark had passed. Such a wire as this
fixed on the jet-pipe, so that the spongy metal shall be exposed to
the current of hydrogen, immediately inflames it. It happens that
if an instrument of this kind has been exposed for some hours to a
humid atmosphere, the inflammation does not take place readily, but
in this case if the top of the platina be touched by the finger or palm
of the hand, either before or during the time that the current of hy-=
drogen is passing out, the inflammation immediately takes place.
Contact, indeed, is not necessary, for the mere approach of the hand
is sufficient to elevate the temperature so much as to cause instant
inflammation.

In using spongy platina for eudiometrical purposes *, M. Dobe-
reiner attaches his balls to the end of a platina wire, so as to be able
to withdraw them when the experiment is completed, or even during
the experiment if requisite, so that they may be dried and again
introduced.—Bib. Univ. xxv. 117.

10. Test of the Alteration of Soiutions by contact with Air.—
M. Becquerel remarks, that if iron be dissolved in nitric acid, and
the solution filtered, and two plates of platina connected with the
two extremities of the wire of a galvanoscope, be immersed into
the solution, and if one plate be withdrawn, and then re-introduced
into the solution, it will produce an electric current passing from
this plate to the other; and generally the plate withdrawn from the
solution and re-introduced becomes positively electrical.

The nitrates of copper and lead give similar results, but they do
not retain this power, and in the course of a few hours no effects of
this kind are observable. Nitrate of zinc does not operate in this
manner. Suspecting that the effect was due to the action of air on
the film of solution which adheres to the withdrawn plate, the expe-
riment was made in an atmosphere of hydrogen, and then no such
results were obtained. M. Becquerel, therefore, attributes the effec t
to the alteration induced by the air on the portion of solution with-
drawn with the plate, and which, when the plate is re-immersed,
being dissimilar to the fluid that has not been exposed, determines
the current of electricity, The effect of the air he considers is pro=
bably to convert such portion of deutoxide of azote and proto-nitrate
as may have been formed by the action of nitric acid on the metal
into nitrous acid and deuto-nitrate, and that when this has taken place

* See Vol xvi. page 874.

380 Miscellaneous Intelligence.

with all the portions of the solution the power of producing electrical
currents ceases.—Ann de Chim. xxv. 413.

11. Odour of Hydrogen Gas extraneous, Inodorous Hydrogen Gas.
—When hydrogen gas, obtained from a mixture of iron filings and
diluted sulphuric acid, is passed through pure alcohol, the hydrogen
loses its odour in a great measure; and if water be added to the
alcohol it becomes milky; if enclosed in a flask and left for some
days, an odorous volatile oil is deposited, which was contained in
the gas, and which contributed to its well known odour.

Perfectly inodorous hydrogen gas may be obtained by putting an
amalgam of potassium and mercury into pure distilled water, but if
an acid or muriate of ammonia be added to the water, which accele-
rates the development of gas, it gives it the same odour as that re-
marked in the solution of zinc by weak sulphuric acid. ‘This
odour, therefore, does not belong to the hydrogen gas, but is given
to it by impurities. — Berzelius.

12. Inflammation of Sulphuretted Hydrogen by Nitric Acid.—
When a few drops of fuming nitric acid are put into a flask filled
with sulphuretted hydrogen, the hydrogen is oxidized by the nitric
acid, and the sulphur is disengaged in a solid form. If the flask be
closed with the finger, so that the gas which becomes heated cannot
escape, its temperature is raised so much as to produce combustion
with a beautiful flame, and a slight detonation which forces the finger
from the mouth of the flask. ‘This experiment may be made with-
out the least danger, with a flask containing four or five cubical
inches of gas.—Berzelius.

13. Artificial Chalybeate Water.—If a few pieces of silver coin,
(says Dr. Hare,) be alternated with pieces of sheet iron, on placing
the pile in water it soon acquires a chalybeate taste and a yellowish
hue, and in twenty-four hours flocks of oxide of iron appear.
Hence by replenishing with water a vessel, in which such a pile is
placed, after each draught we may obtain a competent substitute for
a chalybeate spring.

14, Mercurial Vapour in the Barometer.—M. Billiet observes, that
“ for a long time past it has been known that during hot seasons mer-
curial vapour has formed spontaneously in the upper part of the baro-
meter tube, which condenses in minute drops on its inner surface. It
is sufficient for the observation of this phenomenon at pleasure to apply
a small tin vessel, filled with ice, to this part of the tube for an hour
or two, On removing the cooling vessel there may be perceived on
the internal surface of the tube a dimness about six lines in diameter,
and by means of a lens it will be found that this is nothing but a

Chemical Science. — 381

mass of minute globules of mercury attached to the glass, those in the
centre being largest. Hence arises the question, whether this vapour
may not have some influence on the oscillations of the barometer ?—
Bib. Univ. xxv. 93.

_ 15. Combustion of Iron by Sulphur.—Dr. Hare makes this experi-
ment in the following manner :—A gun-barrel is heated red at the
butt end, and a piece of sulphur thrown into it ; then either blowing
through the barrel, or closing the mouth with a cork, will produce a
jet of sulphurous vapour at the touch-hole, to which if iron wire
be exposed it will burn as if ignited in oxygen gas, and fall in fused
globules of proto-sulphuret of iron.

16. Ammonia in Oxides of Iron.—M. Chevalier has stated to the
Royal Academy, that he has ascertained the presence of ammonia
in various oxides of iron, and promises further accounts.—Ann. de
Chim. xxv. 429.

17. Iodous Acid.—Il Sig. Sementini, of Naples, has published an
account of a combination of iodine and oxygen, containing less of the
latter principle than iodic acid. Itis obtained in the following man-
ner :—equal parts of chlorate of potassa and iodine are to be triturated
together, in a glass or porcelane mortar, until they form a very fine
pulverulent yellow mass, in which the metallic aspect of the iodine
has entirely disappeared. If there be excess of iodine the mixture
will have a lead colour. ‘This mixture is to be put into a retort
the neck being preserved clean, and a receiver is to be attached with
a tube passing to the pneumatic trough. Heat is then to be applied,
and for this purpose a spirit lamp will be found sufficient; at first a
few violet vapours rise, but as soon as the chlorate begins to lose
oxygen dense yellow fumes will appear, which will be condensed in
the neck of the retort into a yellow liquid, and run in drops into the
receiver ; oxygen gas will at the same time come over. When the va-
pour ceases to rise, the process is finished, and the iodous acid ob-
tained will have the following properties :—

Its colour is yellow ; its taste acid and astringent, and leaving a burn-
ing sensation on the tongue. It is of an oily consistency, and flows
with difficulty. It is heavier than water, sinking in it. It has a par-
ticular odour, disagreeable, and something resembling that of eu-
chlorine. It permanently reddens vegetable blues, but does not de-
stroy them as chloric acid does. It is very soluble in water and al-
cohol, producing amber-coloured solutions. It evaporates slowly,
and entirely in the air. At 112° F. it volatilizes rapidly, forming
the dense vapour before mentioned. It is decomposed by sulphur,
disengaging a little heat, and liberating violet vapours. Carbon has
no action on itat any temperature. Solution of sulphurous acid de-
composes it as well as iodic acid, i the iodine as a brown

2

VoL, XVII.

382. Miscellaneous Intelligence.

powder. It is characterized by the manner in which potassium and
phosphorus act on it: the instant they touch it they inflame; the po-
tassium producing a white flame and dense vapours, but little or no
liberation of iodine ; and the phosphorus, with a noise as of ebullition,
violent vapours appearing at the same time.

The odorous nature of this acid, its volatility, colour, and its
power of inflaming phosphorus by mere contact, shew that some of
the principal characters of iodine are retained, and that it is oxyge-
nated, therefore, in a minor degree, and deserves the name of iodous
acid.

Its composition has not been experimentally ascertained. M. Se-
mentini endeavoured to analyze it by putting 100 grains into the end
of a long sealed tube, and then dropping a small piece of phospho-
rus in, iodine was disengaged, and condensed in the upper part of
the tube, and this was found to amount to 45 grains: but this can
furnish only very uncertain results.

Iodous acid dissolves iodine, becoming of a deep colour, more dense
aud tenacious, and having more strongly the odour of iodine : when
heated the iodine partially rises from the iodous acid, but they can-
not be separated in this way.

M. Sementini believes also in an oxide of iodine, and has given
the name to the black powder, which is produced by the action of
sulphurous acid on iodous acid, and which still contains oxygen ;
but he mentions that this and some other points still require investi-
gation.

The following are the properties of the iodic and iodous acids, by
which a judgment may be formed of their specific difference. Jodzc
acid is solid, white, without odour, reddening blue colours, and then
destroying them. Volatile at 456° F., with decomposition: heated
with charcoal or sulphur it is decomposed with detonation. Jodous
acid is liquid, yellow, odorous, reddening blue colours, but not de-
stroying pau volatilizing at 112° F., and even at common tempe-
ratures without decomposition ; heated with sulphur it is decomposed
without detonation, and inflames potassium and phosphorus by mere
contact,— Bib. Univ. xxv. 119.

18. Preparation of pure Oxide of Uranium.—The following is
M. Arfwedson’s mode of procuring oxide of uranium pure, Finely
pulverized pechblende is to be dissolved by a gentle heat in nitro-
muriatic acid, after which a good deal of water is to be added, anda
little muriatic acid,if necessary, The undissolved matters, consisting
of sulphur, silica, and a portion of the gangue, are to be removed, and
a current of sulphuretted hydrogen passed through the solution as
long as it affects it. The first precipitate is dark coloured, but the
latter portions being sulphuret of arsenic is yellow. On filtration, the
liquor is free from copper, lead, and arsenic, but contains iron,
cobalt, and zinc. It is now to be digested with a little nitric acid to

ae en

Chemical Science. 383

peroxydize the iron, and then decomposed by carbonate of ammonia,
in excess, which leaves the iron and earths ; the filtered solution is to
be hoiled as long as carbonate of ammonia is disengaged, the oxides of
uranium, zinc, and part of the oxide of cobalt falls down, and is to be
collected on a filter, washed and dried. It is then to be heated to
redness, by which it becomes of a dark green colour, and afterwards
by maceration in dilute muriatic acid has the oxides of cobalt and
zinc, with a small portion of oxide of uranium, dissolved out, and
after washing and drying, pure oxide of uranium remains. About
65 per cent. of the pechblende used was obtained in this way.

19. Uranium Pyrophori.—When solutions of per-nitrate of ura=
nium and nitrate of lead are mixed together, and precipitated by
caustic ammonia, a precipitate falls, which M. Asfwedson considers
as an uraniate of lead ; after being washed, heated, and pulverized,
it was of a cinnamon brown colour. This substance being placed
in a tube was heated, and hydrogen gas passed over it, much
water was formed, and it is to be presumed that the lead and the
uranium were both reduced to the metallic state. The product was
a dark brown powder, which when exposed to the air on paper, took
fire and ignited, leaving uraniate of lead asa residue. This singular
phenomenon, which was quite unexpected, may have been occasioned
(M. Arfwedson suggests) by an electro-chemical action between the
two metals, which caused their combustion.

When uraniate of barytes is reduced by hydrogen in a similar
manner it also produced a body presenting the same phenomenon in
the air; and the pyrophorus thus obtained from the uraniate of iron is
still more powerful than either of the former.

20. Atomic ox proportional Weights.—Dr. Thomson gives the fol-
lowing as the most correct expression of the atomic weights of the
substances mentioned according to his last experiments ;

Boracic acid. .. - . 3.00
Tartaricacid , . « . $8.25
Pie ACI Me aw (dno
Fluoboricacid . « . « 4.25
Tartaric acid crystallized. 9.375
Oxygenbeing . . . . 1.00

The crystals of tartaric acid contain 1 proportional of water.— Ann,
Phil. N.S. VII. 245.

21. On the Acetates of Copper. By M. Vauquelin,—The follows
ing results are abstracted from a paper by M. Vauquelin, read to
the Academy of Sciences, Nov. 6, 1823, and published in the Mé-
moires du Museum, x. 295. ;

Analysis of the Crystallized Acetate of Copper.—A given weight was

2D2

384 Miscellaneous Intelligence.

pulverized, mixed with nitric acid in a porcelain crucible, aud heated
ultimately to redness, it yielded 40 per cent. of black oxide of cop-
per. Other portions were heated to a temperature sufficient to dis-
sipate the water, but not to decompose the salt. In these cases the
loss was never more than 10 per cent., and was very constant. In
respect to the acid, two grammes of the salt were dissolved in four
grammes of sub-carbonate of potash; the mixture filtered, all the
soluble portions collected, and after being carefully neutralised by
sulphuric acid, evaporated to dryness, and digested in alcohol. This
solution again evaporated gave 1.8 grammes of acetate of potash,
which containing 0.93 of a gramme of acetic acid, gives a propor-
tion of 46.5 per cent. on the acetate of copper employed. The
atomic composition of this salt is therefore given as nearly the fol-
lowing :—

Acetic acid 2 atoms = 12.7 5or percent 51
Oxide of copper 1 _,, =heLo bt 40
Water Si hes aa = 22:25 re 9

When solution of crystallized acetate of copper is boiled for some
time it is decomposed, a little acetic acid escapes, much black oxide
of copper falls down, and when the decomposition ceases, which it
always ultimately does, another acetate of copper is found in the so-
lution. This decomposition takes place in close vessels, where no
acetic acid is allowed to escape. One hundred parts of the crystal-
line acetate deposit about 14.65 of oxide, leaving in solution 25.35
parts in combination, with twice its weight of acetic acid.

On continuing to boil the solution, no further deposition of oxide
took place ; as concentration proceeded acetic acid escaped, but suf-
ficient remained to keep all the oxide in solution. Ultimately the
usual crystallized acetate was obtained, which when dissolved in
water and boiled, precipitated oxide as before, so that by several
operations the whole might be decomposed in this manner.

Verdigris is known to be a mixture of the crystallized acetate of
copper, and a sub-acetate. A portion of the latter was extracted by
washing pulverized verdigris rapidly, with successive small portions
of cold water, to avoid a decomposition afterwards to be noticed ;
this, when dried, was analyzed in a manner somewhat like the pre-
ceding, and found to consist of nearly 66.5 oxide, and 33.5 acid.
Hence there are three combinations of acetic acid, and oxide of
copper, containing, the first, 66.5, the second, 44.44, and the third
33.34 of oxide, supposing them all dry.

M. Vauquelin remarked also a singular decomposition of verdigris
which takes place spontaneously, and without the assistance of heat.
If 1 of verdigris be mixed with 500 of distilled water, and left at a
temperature of 60° or 70° F. it gradually becomes yellow, then
brown, and in seven or eight days no green portions are observed.
When filtered, per-oxide is obtained, and a blue solution, which

ee

Chemical Science. 385

when boiled becomes turbid, and deposits more oxide. Although the
quantity of water is mentioned above, yet the decomposition takes
place with other proportions, but most rapidly when the proportion is
greatest ; 100 parts. of verdigris were found to leave about 23 parts
of oxide of copper. In order to ascertain the correctness of an
Opinion, that it was the sub-acetate only in the verdigris which
underwent this change, some of that salt was prepared, and one part
mixed with 500 of water, and agitated from time to time. At first
the salt swelled and became flocculent, then it became yellow, and at
Jast brown, diminishing rapidly in volume. These effects were more
rapid in the sun’s rays, without doubt from the heat produced. The
per-oxide, when collected gave 46 per cent. of the sub-acetate em-
ployed, just double that afforded when verdigris was used, and the
soluble crystallized acetate of copper formed remained in the solution,
as.was proved by boiling the solution ; it underwent a further de-
composition, just as the crystalline acetate had done before.

“ Thus,” says M. Vauquelin, “ there are three combinations of the
oxide of copper and acetic acid: Ist, a sub-acetate insoluble in
water, but decomposing in that fluid, at common temperatures be-
coming per-oxide, and an acetate ; 2nd, a neutral acetate, the solution
of which is not altered at common temperatures, but is decomposed
by ebullition, changing into per-oxide, and a super-acetate ; 3rd, a
super-acetate, which, when in solution is not decomposed, cither at
common temperatures, or at the point of ebullition, and which cannot
be obtained crystallized, except by slaw spontaneous evaporation, or
evaporation in a vacuum.” .

22. Duhline or Inuline in the Jerusalem Artichoke.-—M. Braconnot,
whilst engaged lately in an examination of the tubercles of the Heli-
antk.as Tuberosus, or Jerusalem Artichoke, ascertained the presence
of a substance in them, in all respects resembling the Dahline of
M. Payen. The recent tubercles were rasped, pressed, and the
juice collected; left to itself it deposited a substance like starch,
which, when collected and boiled in water, was almost entirely dis-
solved; but on evaporation a substance was deposited like the
Dahline. (See vo}. xvi. p. 387.) M. Braconnot, however, does not
think that this, or M. Payen’s substance should be considered as a
new proximate principle, but considers them both as specimens of
Inuline.—Ann. de Chim. xxv. 361.

23. New Vegeto-alkalies.—Violine.—At a sitting of the Académie
Royale de Médicine, M. Boullay read a memoir on the analysis of
the violet, viola odorata, from which it appears that the violet contains
an active alkaline, bitter and acrid principle, similar to the Emetine
of Ipecacuanha, and which is called by the author, Emetine of the
violet, indigenous emetine, or violine, According to M. Ortfila it

386 Miscellaneous Intelligence.

possesses powerful poisonous qualities. It was found to reside equally
in the root, leaves, flowers, and seeds of the plant; but associated
with different proximate principles, so as to have its action on the
animal system modified.—Jour. de Pharmacie, Jan. 1824,

24. Jalapine or Jalapia—Mr. Hume, jun. of Long Acre, is said
to have discovered a vegeto-alkaline principle in Jalap, and pro-
poses to call it Jalapine. It is procured in the following manner.
Coarsely powdered jalap is macerated for 12 or 14 days, in strong
acetic acid; a highly coloured tincture is thus obtained, which,
when filtered, is to be supersaturated with ammonia, and thmie
violently shaken: a sabulous deposit will fall rapidly, and a few
crystals will form on the sides of the vessel. The deposit and crys=
tals are to be collected and washed with distilled water, again dis-
solved in a small quantity of concentrated acetic acid, and re-pre=
cipitated by ammonia added in excess, which throws down the jala-
pine in small white acicular crystals.

Jalapine is without any perceptible taste or smell, and seems to be
heavier than Morphia, Quinia, or other substances of this class; it is
scarcely soluble in cold water, and only to a small extent in hot
water; ether has no effect upon it; alcohol is its proper solvent.
Very little trouble is requisite to purify jalapine from extractive or
colouring matter, for which it appears to have but a slight affinity.

Mr. Hume has not made many experiments upon this substance,
but thinks that one ounce of jalap will, on careful treatment, afford
about five grains of the substance.—Med. Jour, li. 346.

25. MM. Liebeg and Gay Lussac on Fulminic Acid and Fulminates.
An abstract was given in the last number of this journal, (p. 153..0f a
paper by Dr. Liebeg on fulminating silver, mercury, &c., in w.rich
the author proved that they were saline compounds containing a
peculiar acid, which he called the fulminic acid, and the compounds
of this acid with bases he called fulminates ; shewing at the same time
that they all possessed similar properties to the compounds of silver
and mercury. Since the researches referred to, Dr, Liebeg has been
joined by M. Gay Lussac in further investigations on this subject, and
the remarkable result has been obtained that cyanic acid is the true
acid existing in these compounds. The paper containing these ulti-
mate investigations is published in the Annales de Chimie, xxv. 285.
and contains admirable examples of chemical reasoning and mani-
pulation ; but we cannot do more at present than give a very brief
account of if. ‘

The compound principally experimented on was that of silver ; the
fulminate of silver from its insolubility being more readily obtained
perfectly pure than any other. It was prepared by putting 6.5

Chemical Science. 387

grains of nitric acid,” s.g. 1.56 or 1.38 into a pint matrass, and a
piece of coin, containing nearly 35 grains of pure silver. The re-
sulting solution was poured into about 927 grains of strong alcohol,
and heated until it boiled; on the appearance of turbidness it was
removed from the fire, and an equal quantity of alcohol added by
degrees to cool the solution and moderate the ebullition. When
cold, the whole was filtered, and the precipitate washed with pure
water until no longer acid. It is then perfectly pure, and white as snow.
The filter was put on a plate which was placed on a saucepan half
filled with water, and heated to 212°, for two or three hours, that it
might be perfectly dry ; its weight was generally equal to that of
the silver employed,

Tulminate of silver will not detonate alone at 212° F, or even at
266° F. but a slight blow between two hard bodies, even under
water, will explode it : hence wooden stirrers and paper spoons should
be used in experiments made with it.

When mixed with 40 times its weight of per-oxide of copper it
may be rubbed in a porcelain capsule with the finger, or a cork, and
does not then detonate by heat. This mode of analysis was therefore
adopted to ascertain the proportion of carbon and nitrogen in the salt,
or rather in the acid. ‘The gaseous mixture obtained by heat con-
tained exactly 2 volumes of carbonic acid, and 1 volume of nitrogen:
hence, these elements are in the same proportion as in cyanogen.

Fulminate of silver contains two proportions of oxide, one belong-
ing apparently to the acid, and the other, serving as base: Muriatic
acid ; entirely decomposes the fulminate, giving a chloride equivalent
to the oxide contained in the metal; operating in this way, 100 of
the compound gave as a mean result, 77.528 of oxide of silver, or

Silver . . 72.187
Oxygen . 5,341

It is assumed that the silver is all in the state of oxide, a supposition
supported by alithe results.

Muriate of potash precipitates only the silyer serving as base, and
does not affect that of the fulminic acid ; and operating with it instead
of muriatic acid, 100 of the compound gave a quantity of chloride
equivalent to 38.105 of oxide of silver; and the solution remaining,
which contained the fulminic acid united to potash, when decomposed
by muriatic acid yielded chloride equivalent to 38.359 oxide of silver.
Oe it may be concluded that the fulminate of silver contains twice
as much oxide of silver as will saturate fulminic acid.

When the compound was decomposed by oxide of copper and heat,
a process which was conducted with the utmost attention and accu-
racy, 100 of fulminate of silver gave a mean of carbon and nitrogen,
equivalent to 17.16 of cyanogen; small quantities of water were
obtained, but they were irregular, and never amounted to any thing
like a proportional of hydrogen in the compound. Other proofs

388 Miscellaneous Intelligence.

were also obtained during the investigation of the absence of hy-
drogen,
Thus far, then, the elements obtained from the fulminate of silver

were:

Silver het sive) \TREST

Oxygen. . 5,341

Cyanogen . . 17.160

Feossv 3.) h sly ithe 2942

100.000

The loss is very nearly equal to the quantity of oxygen combined
with the silver, it could not be hydrogen or water, neither of which
could have escaped the search made by the experimentalists, it could
only therefore be oxygen contained in the fulminic acid, a supposi-
tion ultimately confirmed. Fulminate of silver, therefore, contains

2 atoms of silver,

2 atoms of oxygen combined with the silver,

2 atoms of oxygen combined with the elements of fulminic
acid,

2 atoms nitrogen,

2 atoms of cyanogen, = j el cde eacialanen

It was desirable, if possible, to ascertain the products of the de-
tonation of this substance, but after some trials the danger made it
necessary to desist. Endeavours were then made to decompose it by
heat, when previously mixed with substances that could not furnish
oxygen. Glass in impalpable powder always exploded it, but
chloride of potassium and sulphate of potash fused and finely pul-
verized could be mixed with it by the finger or 2 cork without pro-
ducing explosion. The chloride of potassium gave inconvenient and
uncertain results, in consequence of its partial decomposition by the
silver, and the production of carbonate of potash, as well also as of
carbonate of ammonia. When the sulphate of potash was used, the
gaseous and other results furnished by heating the fulminate were
first collected, examined, and ascertained, and then the residue in
the tube was mixed with oxide of copper, and heated for the decom-
position of the substance operated en. A quantity of nitric acid was
produced in the latter part of the operation, and at times also car=
bonate of ammonia in minute quantity; in the latter case no water
could be perceived, and it appeared that the formation of one of
these compounds excluded that of the other; for it was found by
direct experiment that when the fulminate was first slightly moistened
much carbonate of ammonia was formed: thus then a new proof
was obtained of the absence of hydrogen from the compound, for
the quantity of carbonate of ammonia was so small, it could not
have resulted from any proportional quantity of hydrogen in union

Chemical Science. 389

with the other elements, but only from a minute trace of water in-
troduced with the materials operated upon.

From further experiments of this kind it was concluded, that
when fulminate of silver mixed with sulphate of potash was decom-
posed by heat, only half its carbon became carbonic acid, and only
that proportion of nitrogen was set free which with the carbon would
form cyanogen, so that the silver was left in a state of asubcyanuret.

If the elements thus analytically obtained are correct, the follow-
ing will be the equivalent number of fulminic acid:

1 atom oxide of silver . » 145.161

2 — cyanogen ‘ ‘ 65.584
2 — oxygen. : . . 20.000
230.745

and on experiment it was found that 3.833 of fulminate of baryta
decomposed by muriatic acid gave 1.585 of chloride of barium,
which by calculation would give 228.873 as the number of fulminic
acid, a result sufficiently in accordance with the former to justify the
calculated number.

The authors then consider the probable nature of fulminic acid.
That the metal should be an essential principle can hardly be ima-
gined, inasmuch as one metal may be replaced by another; thus a
fulminate may be obtained with zinc only, analogous to that of silver :
are not therefore the various fulminic acids formed by the different
metals super salts, of which the acid really contains no metal but
only cyanogen and oxygen ?

As fulminates may be obtained with oxides which lose their
oxygen with difficulty, oxide of zinc for instance, as well as with
silver or mercury, it is evident they must all include one common
principle of fulmination independent of the bases, and which can
only be acompound of oxygen and cyanogen, or of oxygen, car-
bon, and nitrogen. Again, if the fulminates be compared to neu-
tral tartrates, and the various fulminic acids to bitartrate, a perfect
avalogy will be found; thus neutral tartrates of zinc, copper, silver,
or mercury, are only half decomposed by potash, just like the
fulminates of the same bases: all the fuliminic acids form double
salts with bases like the bitartrates: fulminic acid with a base of
silver is, in consequence of its insolubility, precipitated by acids
like cream of tartar : and there are many fulminates, as well as neu-
tral tartrates, in which acids produce no precipitates, because the
corresponding acid fulminates, or tartrates, are soluble; such are
the fulminates and tartrates of zinc and copper. Hence it appears
to the authors extremely probable, if not certain, that the various
fulminates form a particular class of salts, all containing the same
acid composed of an atom of cyanogen and an atom of oxygen only,
and which is without doubt the cyani¢ acid, The neutral fulminates

390 Miscellaneous Intelligence.

are cyanates, and the various fulminic acids bi-cyanates, and the
equivalent number of cyanic acid will be 42.792, oxygen being 10.

All attempts to separate the acid from the fulminates failed. Mu-
riatic acid, hydriodic acid, and sulphuretted hydrogen, decompose
the fulminate of silver even at common temperatures, giving rise to
some particular results, which are described at considerable length in
the Memoire.

For the preparation of alkaline fulminates, it is recommended that
the chlorides should be used: thus, to obtain the double fulminate
of silver and potash decompose the fulminate of silver by solution
of chloride of potassium, being careful to add no more of the chlo-
ride than is sufficient to precipitate half the silver, or even a smaller
quantity; for the undecomposed fulminate of silver being scarcely
soluble, will remain with the chloride of silver, and the solution
will contain the pure double fulminate of silver and potash. Cau-
tions are again enforced at the end of this paper on the care required
in working with these substances.

26. Supposed new Metal, Taschium.—A description of a new
metal, with an accompanying specimen, has been sent to the Presi-
dent of the Royal Society.

The metal has received the name of Taschium, from the mine of
Taschio, in which it was found.

The specimen sent was said to be silver containing the new metal,
the two metals having been separated by amalgamation, and the mer-
cury afterwards driven off. On dissolving the button in pure nitric
acid, it was stated that the Taschium would remain as a black powder.

The Taschium was described as being combustible, with a bluish
flame, a peculiar smell, and dissipation of the products. Amal-
gamating with mercury, and in that way being separated from its
ores. Not soluble in any single acid, but soluble in nitro-muriatic
acid. If previously boiled with potash, then soluble in muriatic
acid, the solution being precipitated by water. Its solution giving,
with prussiate of potash, a blue precipitate brighter even than that
with solution of iron, but not precipitating with tincture of galls.

The button was therefore dissolved in nitric acid, which left a
blackish powder in small quantity, and also some grains of siliceous
sand. The powder was well washed, and then being heated on pla-
tina foil in the flame of a spirit lamp, did not burn or volatilize,
but became of a deep redcolour. Muriatic acid being added to
another portion of the washed powder, and a gentle heat applied,
dissolved by far the greater part of it, forming a red solution, which
being evaporated till the excess of acid was driven off, and then
tested, gave blue precipitate with prussiate of potash; black with
tincture of galls; and reddish-brown with ammonia. On evapo-
rating to dryness, it left muriate of iron. Nitro-muriatic acid being
made to act on the minute portion of powder yet remaining, dis-

Chemical Science. 391

solved very nearly the whole of it, leaving a small trace of silica,
and producing a solution similar to the former. Hence the Taschium
in this button of silver was nothing else than iron; and from the
‘presence of silicious sand it may be supposed to have been intro-
duced into the button through the inaccuracy of the preparatory
manipulations.—M. F.

27. Liquefaction of Sulphurous Acid.—In the Annales de Chimie et
Physique for May last, M. Bussy is stated to have obtained the above
acid liquid, and free from water, by causing it to pass in its gaseous
state through a tube containing fused chloride of calcium, and after-
wards into a flask surrounded by a mixture of ice and salt, where it
completely liquifies, and remains in a liquid state under atmospheric
pressure at the temperature of 0°. Itis a colourless, transparent, and
very volatile liquid, of a specific gravity ='1.45. It boils at about
10° centigrade below 0 = 14° Fahrenheit, but in consequence of the
cold produced by the evaporation of the portion which is volatilized
the residue remains liquid, being reduced to a temperature much
below its boiling point. It occasions intense cold, and rapidly eva~
porates when dropped upon the hand, Poured into water at com=-
mon temperatures one portion is dissolved and another volatilized ;
but as the solution approaches to saturation, the acid collects in
drops at the bottom of the vessel, like an oil heavier than water.
If in this state it be touched by the extremity of a glass tube, it
passes into vapour, occasioning ebullition, and ice forms upon the
surface of the water.

The bulb of a thermometer enveloped in cotton, and dipped into
the liquid acid, falls spontaneously, when exposed to the air, to
— 57°. (= — 70° Fahr.) The atmosphere being at 50° F. In the
vacuum ofthe air-pump a cold of —68° (=—90° F.) is thus easily
obtained*. Mercury therefore is easily frozen by the aid of this
acid, simply by dipping the bulb of a mercurial thermometer sur-
rounded with cotton into it, and agitating the air with it. The ex-
periment succeeds better when a little mercury is put into a cup
with a small quantity of sulphurous acid upon it, and the whole
put under the exhausted receiver. By the evaporation of the acid
in vacuo, M. Bussy has frozen alcohol of a strength below 33° (of
a specific gravity below .852 at 55°). By passing chlorine and am~-
monia through tubes cooled by the evaporation of sulphurous acid,
M. B. liquefied those gases; and by a similar method cyanogen was
obtained in the form of a crystallized solid.

* M. Bussy says these low temperatures can only be accurately measured
by an air thermometer.

392 ©
III. Narurat History.

1. On the different Manners in which Bodies act on the Organs of
Taste, by M. Chevreul.—Persuaded as I am that many phenomena
appear complicated to us only because they are the results of many
causes acting simultaneously, I have adopted as a principle, when I
examine phenomena of this kind, to endeavour to separate the dif-
ferent causes which may operate so as to refer to each the effects de-
pendant on it. Viewing from this point the varied sensations which
we perceive when substances are introduced into the mouth, I have
arrived at a satisfactory analysis of these sensations in recognising
those which are perceived ; Ist. By the touch of the tongue; 2d,
by the taste; 3d, by the smell. It is generally known that we can
perceive these three orders of modifications by the introduction of
substances into the mouth; but since no physiologist that I have
consulted has indicated the means of recognising the special modi-
fications belonging to the senses of touch, taste, and smell, I have
determined to publish the following results, which make part of my
general considerations on immediate organic analysis, and on the
application of this branch of chemistry to the history of orgunized
beings.

It is not possible to separate the action which a substance intro-
duced into the mouth exerts on the touch from that exerted by it on
the taste, but it is easy to distinguish the effects produced on each of
these senses; for that purpose one must first appreciate the effect
produced by the substance on the organ of touch by applying it to
some other part of the body than the tongue, and then this effect
may mentally be abstracted from that produced when the substance
is put into the mouth, and by this means the effect produced on the
taste will be obtained, except that as the tongue is more sensible
than the skin, the sensation of touch on the tongue will be stronger
than that on the skin elsewhere. For instance, if a little powdered
chloride of lime be pressed upon the skin the water of transpiration
will be solidified by the compound, and a sensation of heat expe-
rienced, | If, on the contrary, crystallized muriate of lime in pow-
der be used, it will liquefy, and a cold sensation be felt. It is evi-
dent therefore that chloride of lime put into the mouth will produce
heat, whilst the muriate of lime will produce cold, and that these
effects will be more marked than on the surface of the body, since
the tongue is more sensible and more humid than the skin. The
substances which fusing or evaporating on the surface of the body
produce cold, will also produce the same effects in the mouth if
they fuse or evaporate there.

But how are the sensations of smell to be separated from those of
the touch and taste? Very simply; pressing the two nostrils one
against the other is sufficient to prevent all sensation of smell, because

Natural History. 393

then the air, which becomes more or less charged with the odorous
particles which a sapid and odoriferous substance in the mouth has
emitted not being able to pass by the nose, cannot any longer carry
those particles to the membrane which occasion the sensation of smell.
When therefore the nostrils are pressed together, no other sensations
are perceived than the taste and the touch of the tongue. One can
hardly form an idea of the extreme difference which exists between
the sensations produced by a sapid and odorous substance in the
mouth according as the passage of the air expired by the nose is
open or interrupted.

I have ultimately established four classes of bodies relative to the
sensations which they excite when put into the mouth, amongst
which I do not include those caustic substances which attack and
alter the organs.

Ist Class. Bodies which act on the tongue only by touch.—Rock-
crystal, sapphire, and ice.

2d Class. Bodies which act by »y touch on the tongue and by smell.—
The odorous.metals: when tin is put into the mouth the odour of
that metal is perceived; but on pressing the nostrils all sensation, ex-
cept that of touch only, entirely disappears,

3d Class. Bodies which act by touch on the tongue and by tasteom—
Such bodies as these are sugar, salt, &c. When these substances
are put into the mouth the sensations they cause are not modified by
pressing the nostrils together.

Ath Class. Bodies which act by touch on the tongue, and by taste
and smell, Examples 1. Volatile Oils.—They are generally acrid,
but with a particular odour for each sort of oil. When put into the
mouth, and the nostrils are pressed, the acrid gemsation: is always
sensible, whilst that of smell vanishes entirely. 2. Lozenges of Pep-
permint, Chocolate, &c.—When the nostrils are saa “after these
have been introduced into the mouth, nothing is perceived but the
savour of the sugar ; but if the nostrils be relieved, the odour of the
peppermint or the chocolate becomes evident.

It will not be useless to remark that the urinous taste attributed to
fixed alkaline bases, does not belong to these substances, but to the
ammonia, which is set at liberty by their action on the ammoniacal
salts contained in the saliva. ‘The proofs of this are the disappear-
ance of the sensation referred to, when the nostrils are pressed, and
the perception of the same sensation when one smells to a mixture of
recent saliva and alkali, made in a small glass or porcelain capsule. |

It appears that the sense of smell weakens by age, before that of
taste.—Mem. du Mus. x. 439,

2. Action of Meconic Acid on the Animal Economy.—Doubts hav-
ing arisen with regard to the effects produced by pure meconic acid
and the meconiates on the animal system, i Signori Fenoglio, Cesare,

394 Miscellaneous Intelligence.

and Blengini, of Turin, prepared some of these substances very care=
fully, and administered them in cases where the results could be
accurately observed. It was found that eight grains of any of these
substances produced no deleterious effects on dogs, crows, or frogs ;
nor on a horse even when the dose was repeated. ‘The meconiates
were also administered to two persons in cases of teenia, in doses of
four grains, but without producing any effect either on the persons
or the worms. These results agree with those obtained by MM.
Suertuerner and Semmering : and in those cases where death was
produced by doses of a grain of meconic acid, Dr. Fenoglio attributes
the results to the defective preparation of the substance, and the pre-
sence of morphia in it; and the symptoms observed seem to accord
with this opinion.

3. On the different masses of Iron which have been found on the
Eastern Cordbiliera of the Andes. By MM. de Rivero and Boussin-
gault.—On arriving at Santa Rosa, a village situated on the road
from Pamplona to Bogota, we learnt that a mine of iron had been
discovered in the neighbourhood, and that a fragment of the mineral
served for an anvil to a farrier (or blacksmith) ; but we were agree-
ably surprised when we saw that this supposed mineral was a mass
of iron full of cavities, of an irregular form, and presenting all the
characters of meteoric iron.

This mass was found on the hill of Tocavita, about a quarter of a
league to the east of the village in 1810. We went to the place, and
saw the hole from whence the mass had been removed, for it was
almost entirely under-ground, a point of a few inches only appearing
at the surface. The hill of Tocavita, like that of Santa Rosa, belongs
to the secondary sandstone formation, and which we have observed for
a considerable extent.

Santa Rosa is about twenty leagues N.E. of Bogota, lat. 5° 40’,
long. 75° 40’ west of Paris, and 2744 metres (9003 feet) above the
sea. The people of the village collected together to remove the mass
of iron: it remained eight years at the town-hall, and afterwards for
seven years did service in the blacksmith’s shop.

The iron was cellular, but no vitreous coat could be perceived on
ite It was malleable, of a granular structure, easily gave way to the
file, was ofa silvery aspect, and its specific gravity 7.3. The volume
of the mass was 102 cubic decimetres (3.6 cubical feet), its weight
therefore must be nearly 750 kilogrammes (1655 Ibs.)

It is worthy of observation, that at the same time that this mass
was discovered, a number of smaller fragments were found on dif
ferent parts of the same hill. During the short time which we re=
mained in the place, we collected several specimens. To demonstrate
the identity of these masses with those which various travellers have
described, some chemical examinations were undertaken, The usual

Natural History. 395

process of analyses is'then described. A portion of the large mass
yielded ‘

Oxide ofiron . 1.17 1 ee 91.41

Oxide of nickel 0.15 ” Nickel . 8.59

100.00
Some of the other fragments were then examined. ‘* We com-
menced with a mass weighing 681 grammes (10,517 gr.) discovered
in 1810, near Santa Rosa. It was malleable, but difficult to file. Its’
lustre was silvery ; its grain fine like that of steel; it forged very well
but was red short ; its specific gravity 7.6 ; it gave,

Oxide of iron , 9.46 Tron 91.23
Oxide of nickel 0.75 or Nickel 8.21
Insoluble in nitric acid 0.02 Residuum 0.28

99.72

The insoluble portion was difficultly acted upon by hot nitro-muri-
atic acid ; it appeared to be a compound of nickel, iron, and perhaps
a little chromium.

Another fragment of 561 gram. (8664 gr.) found at the same time
near Santa Rosa, was cellular, very hard to the file, but malleable, of
a silvery aspect, and a fracture resembling that of tilted cast-steel ; it
gave,

Oxide ofiron . 2.62 Tron 91.76
Oxide of nickel . 0.16 “ Nickel 6.36
98. 12

We have also ascertained the presence of nickel in a Bred num-
ber of other fragments, collected at the same time near Santa Rosa, the
weight of the largest being 145 grammes (2229 grs.) But itis not there
only that metallic iron has been found ; it has also been discovered at
a village called Rasgata, i in the neighbourhood of the salt-works of
Zipaguira, lat, 4° 57’, long. 76° 33° west of Paris, and 2650 metres
(8694 feet) above the need of the sea. We saw one mass in the
hands of M. Geronimo Torres weighing 41 kilogrammes ( Ibs.)
We could perceive no cavity in it ; its texture exhibited small facets;
it was very hard to the file, was malleable, of a silvery lustre, and a
specific gravity of 7.6 ; it gave,

Oxideofiron . 5,23 «ss Iron. 90.76
Oxide of nickel . 0.40 Nickel . 7.87
98.63

Another mass weighing 22 kilogrammes (90.5 lbs.), which was,
shewn us at the same place, was nearly spherical, and contained
many cavities. It was very malleable, and its fracture had a silvery
lustre. We found from seven to eight per cent. of nickel in itx—dnn.
de Chim, xxv. 438,

4, Natural Ice Caves.—1n a memoir on some natural ice caves, read

396 Miscellaneous Intelligence.

by Professor Pictet, to the Helvetic Society, in 1822, the author had-
advanced the singular fact, attested by the neighbouring inhabitants,
that the ice forms more in summer than in winter, and conceived that
this effect might be due to two concomitant causes ; descending cur-
rents of air, and the cold produced by evaporation.

{It was desirable that this fact should be confirmed by observation
made in the winter ; a season, however, when the fall of snow pre-~
vented ascents to any great height. One of these natural ice caves
visited by Professor Pictet, is situated near the crest of the Mont
Vergy, in Faucigny ; itis called from the name of the neighbouring
chalet, Montarguis. ‘Two countrymen of the village of Sionzier, near
the road to this ice-cave, had the curiosity and perseverance to make
three visits to this place during the last autumn and winter, and have
drawn up a short notice, which has been read to the Geneva Society.
It is as follows :

“© The 22d Oct. we ascended to the ice-cave of Montarguis with
some little trouble, because of the first snow, and we found very
little ice in columns ; it had begun to melt.

‘* The 26th November we re-ascended to the before-mentioned
ice-cave. There we found very little ice at the bottom of the cave,
out of which came a sort of warmth.

** The 25th Dec. we re-ascended to the above-mentioned cave
with much difficulty and trouble, and were almost carried away by
an avalanche. This circumstance discouraged us, but recovering
from our fear we ascended. There we found a moderate warmth in
the cave, and noice; instead of which where there is ice in summer,
there was actually water: therefore in winter it is warm in this ca-
vern, and in summer it is cold. The roof appears cavernous ; it
appears as if there were chimneys.”’

The fact, therefore, seems well ascertained, and the editor of the
Bibliothéque Universelle observes, that the concluding remark comes
in support of the explanation given by Professor Pictet, depending on
descending currents of air, cooled by evaporation, whilst traversing
considerable strata of stones constantly moist. ‘This effect can only
take place in summer, for in winter the current of air would be
ascending from the superior warmth of the interior to the exterior.

The descending current of cold air was observed during the last
summer by M. Gampert, who visited this cave, and penetrated to
its extremity ; there he discovered a crevice, or aperture, by which
water descended and flowed over the ice, and also a very rapid cur-
rent of very cold air.—Bzb,. Univ. xxv. 243.

5. Glacier of Getros, Valley of Bagne.—The glacier of Getros, in
the valley of Bagne, has‘been noticed at different times in this journal*,
and the ingenious and successful means adopted by M. Venetz for its

* See Vols. v. p. 372. vi. 166. xv. 396.

Natural History.. 397

destruction described. This means had, at the end of the summer of
1822, reduced the glacier, which originally covered the river for a
length of 1350 feet, to an extent of 498 feet only. The cold-winter
of 1822-3 and the following spring, increased the glacier to 924 feet,
and this new part was excessively rugged and dangerous to work upon,
and continually exposed to masses falling from the upper glacier. It
was requisite, however, that this should be first destroyed, which was
done atthe risk of many serious accidents by currents of water as
before, during the summer of 1823, and such advantage taken of the
rest of that cold short summer as to diminish the whole glacier to 252
feet only. Thus, notwithstanding the accessions which it must have
teceived during the last winter, there is little doubt but that it will
be entirely removed during the present sum mer, and then the course
of the river being open, it will generally remove all the avalanches
that may fall at any future period ; or if a disastrous year like that of
1816 gives rise to the formation of a new glacier, the means for its
removal are known, and may be practised before the formation of
another lake can again destroy the country.

Vor. XVII.

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INDEX.

Acetate of lime, phosphorescence of, 163. Of morphia, how
detected in cases of poisoning, 168—170. Of copper, 383—383

Acids, succinic and benzoic, facts relative to the history of, 141.
Preparation of sulphurous acid gas, 163, 164. Acid tartaro-
‘sulphate of potash, 171. Conversion of Gallic acid into ulmin,
174. Analysis of sodous acid, 381, 382. Liquefaction of
sulphureous acid, 391. Action of the meconic acid on the
animal economy, 393, 394

Algol, table of the recurrence of the smallest light of, 184, 185

Analyses of scientific books, 105—130, 335—359. Of cafeine,
174. Of sodous acid, 381, 382

Arfwedson, (M.) his mode of procuring the pure oxide of uranium,
382. And uranium pyrophori, 383

Arsenic, detection of, in cases of poisoning, 165

Astronomical and Nautical Collections, 85—104, 295—334 ;

Astronomical Phenomena, for April, May, and June, 1824, 77—84
‘And for July, August, and September, 238—244,

Atmosphere, a finite and exact expression for the refraction of one,
nearly resembling that of the earth, 255, 2.56

Atomic Weights, table of, 383

Badnall, (Mr.) improvement of, in dyeing with Prussian blue, 167

Bakewell, (Mr.) theory of, to account for the production of sound
by opening a subterraneous gallery, 152. Table of vegetation
at different heights, 176

Barlow, (Peter, Esq.) experiments and observations by, on the
daily variation of the horizontal and dipping necdles, under a
reduced directive power, 128 '

Barometer, horary oscillations of, 189—197, Remarks on the ba-
tometer, 345—347. On the formation of mercurial vapourin, 380

Becquerel, (M.) account of the electrical effects produced at the
moment of the combination of the metals and alkalis, with the
acids, 136—138. Observations of, on the electro-motive actions
produced by the contact of metals with liquids, 374, 375. His
test of the alteration of solutions by contact with air, 379

Bell (Charles, sq.) on the motions of the eye, in illustration of
the uses of the muscles and nerves of the orbit, 123, 124, 127

Berthier, (M.) on the preparation of sulphuretted hydrogen, 164.
Of the saturated hydro-sulphuret of potash or soda, 165. And
of the pure oxide of nickel, 166.

Berzelius (Professor) letter ae 274

400 INDEX.

Bevan, (Mr.) experiments by, on the adhesion of nails, in different
kinds of wood, 360

Blainville (M.) sur les Ichthyolites, analysis of, with strictures on
his errors and the imperfections of his work, 105—121

Blowpipe, self-acting, described, 236, 237

Boussingault and Rivero, (MM.) Memoir of, on the milk of the
Cow tree, 142. On the hot springs of the Cordilleras, 143

Brande, (W. T., Esq.) prospectus of his course of lectures on elec-
tricity, 282—284. And on vegetable chemistry, 288—289

Brard, (M.) on the action of frost on building materials, 148, 149

Brinkley (Dr.) remarks on the parallax of a Lyree, 264, 265

Brisbane, (Sir Thomas) account of experiments made by, with an
invariable pendulum, at New South Wales, 128

British Channel, observations on the soundings in, 245—247

Cafeine, composition of, 173, 174

Caoutchouc, observations on the preparation of, 364

Capillary Action of fissures, §c., remarks on, 151, 152

Carrara Marble, natural changes in, 178

Chalk, observations on the burning of, 361—363

Chalybeate Water, artificial, notice of, 386

Cheltenham Water, existence of nitrate, and a salt of potash, dis=-

covered in, 178, 179
Chemical Science, intelligence in, 153—175, 369—386
Chevreul, (M.) observations of, on the action of bodies on the
organs of taste, 392, 393
Chili, account of the earthquake in, in Noy., 1822, 38—46
Chiswick, account of an overflowing well at, 70—74
Christie, (Samuel Hunter, Esq.) observations on the diurnal varia-

tions of the horizontal needle, when under the influence of

magnets, 128, 129. And on the effects of temperature on the
intensity of magnetic forces, 279

Chronometers, influence of magnetism on, 197—202, 365—367

Climate of London, meteorological remarks on, 340—345

Coal Strata, products of the combustion of certain, 180

Coindet, (C. W.) account by, of the injection of a solution of opium
into the veins of an hysterical patient, 145, 146

Collyer, (Charles, Esq.) observations by, on univalves, 272, 273

Comets, remarks on the catalogue of the orbits of, that have hitherto
been computed, 85—96. Remarks on the periodical comet (86
Olb.) 96—99. Elements of the comet of 1823,4, by various
computers, 104

Conchology, observations on the present state of, 29, 30

Condensation of Gases, experiments on, 123, 124, 125.

Conductors (fluid), on the motions produced in, when transmitting
the electric current, 256—259

Cooper (Mr.) analysis by, of the ancient ruby-glass, 165. Descrip-
tion of his lamp-furnace for the analysis of organic bodies, 232

INDEX. 401

Copper, experiments on the acetates of, 383—385 _
_Copper-sheathing of ships, how prevented from corrosion, 253 9

Cordilleras, on the hot-springs of, 143. Account of the different
masses of iron which have been found n the eastern Cordillera
of the Andes, 394, 395 ;

Cow-Tree, memoir on the milk of, 142, 143

Crotch (Dr.) syllabus of his course of lectures on music, 287

Croup, sulphate of copper an excellent remedy in, 181

Crystal, unequal dilation of, in different directions, 157. Differ-
ence of crystalline forms of the same substance, zhid., 158

Crystallization, supposed effect of magnetism on, 158. Of the
sub-carbonate of potash, 167

Dahline, discovery of, in the Jerusalem artichoke, 385

Daniell (J. F., Esq.) observations and experiments on evapora-
tion, 46—61. On the horary oscillations of the barometer,
189. Review of his Metereological Essays and Observations, 335

Davy (Sir Humphrey) on a new phenomenon of electro-magnetism,
122, On the application of liquids, formed by the condensa~-
tion of gases, as mechanical agents, 125, 126.. On the mode
of preventing the corrosion of copper-sheeting by sea-water, in
ships, 253—279—280

Davy (Dr. John) on air found in the pleura, in a case of pneu-
mato-thorax, 130, 263

Debret (M.) experiments of, on the comparative advantage of cok
and wood, as fuel, 361

Dew, observations on some phenomena relating to the formation
of, on metallic surfaces, 1—12

Dillwyn (L. W.) observation of, on fossil shells, 129, 267

Dipping-needle, general results of, 104, Experiments and ob-
servations on the daily variation of the horizontal and dipping-
needles, under a reduced directive power, 128, 129.

Dobereiner (M.) on the capillary action of fissures, 151, 152. No-
tice of his instantaneous light apparatus, 378, 379

Dulong and Thenard (MM.) Experiments on the property which
some metals possess, of facilitating the combination of elastic
fluids, 132, 133

Earthquake in Chili, account of, 383—46

Electrical Machines, variation in the construction of, 161. Account
of an electrical arrangement, produced with different charcoals
and one conducting fluid, 174, 175.

Electricity, connexion of phosphorescence with, 163. Electricity,
on the separation of parts, 162. Electric light, 162. Observa-
tions on a reciprocity of insulating and conducting action, which
the incandescent platina of Davy exerts on the two electricities,
369—372. Measurement of the conductibility of bodies for
electricity, 376. Destruction of positive and negative electricity,
377. Electricity produced by congelation of water, ibid, On

402 INDEX.

the magnetic action of strong electrical currents on different
bodies, 372, 373. .

Electro-Magnetism, on a new phenomenon of, 122. Electrical
effects produced at the moment of the combination of the metals
and alkalis, with the acids, 136—138. On electro-magnetic
multipliers, 161. On electro-motive actions produced by the
contact of metals and liquids, 374.

Electrometer of Dr. Hare, notice of, 377.

Encke (Professor) on the periodical comet (86 Olb.) 96

Erman (M.) experiments and observations of, on a reciprocity of in-

» sulating and conducting action, which the incandescent platina
of Davy exerts on the two electricities, 369—372,

Evans (Col.) experiments of, on the action of sulphur on iron, 165

Evaporation, observations and experiments on, 46—61

Lye, on the motions of, in illustration of the uses of the muscles and
nerves of the orbit, 123, 124, 127. Observations on the appa-
rent direction of the eyes in a portrait, 264—276 “a

Fallows (Rev. F.) an easy method by, of comparing the time indi-
cated by any number of chronometers with the given time at a
certain station, 315, 316

Faraday (M.) experiments on fluid chlorine, 123. And on the
condensation of several gases into liquids, 124, 125. On the ex-
istence of a nitrate and a salt of potash in Cheltenham waters, 178

Ferrari (M.) process of, for obtaining strychnia, 170, On the
volatility of salts of strychnia, abed., 171

Fiedler and Hagen (MM.) observations of, on sand-drigs or fulgo-
rites, 181—183

Fish, Chinese mode of hatching, 176

Fishes, observations on the possibility of changing the residence of
certain, from salt water to fresh, 209—-231]. On the generation
of fishes, 277

Fissures, on the capillary action of, 151, 152

Fossil Shells, observation on, 129, 267

Frost, test for the action of, on building materials, 148, 149

Frost (Mr.) syllabus of his course of lectures on botany, 284, 285

Fuel, comparative advantage of coke and wood for, 361

Fulminating silver and mercury, results of experiments on, 153—
157

Fulminic Acid and fulminates, experiments on and analysis of, 386

Gases, experiments on the condensation of, 123, 124, 125. On the
application of liquids, formed by such condensation, as mecha-
nical agents, 125. The odour of hydrogen gas extraneous, 380

Geneva, expense of the iron-wire suspension bridge at, 148. . Its
durability, 147

Getres, notice of the remoyal of the glacier of, 396, 397

Goring (Dr.) On indistinctness of vision, caused by the presence of
false lights in optical instruments, and remedies for it, 1728,

INDEX. 403.

* 202—209. On the adaptation of a compound microscope, to act

. as a dyrameter for telescopes, 367—369

Griffiths (Mr. T.) account of an electrical arrangement produced

_ with the different charcoals and one conducting fluid, 174, 175 —

Groombridge (Mr.) comparison by, of the new tables of refraction

with observation, 100—103

Guiana, the common, observations on, 255

Hall (Capt. Basil) results of experiments made by, with an invari-
able pendulum, 126

Hancock (Mr.) process of, for preparing caoutchouc, 364

Hare (Dr.) account of his single gold leaf electrometer, 378. And
of his voltaic trough, 2bid. On the preparation of artificial cha-
lybeate water, 380. On the combustion of iron by sulphur, 381

Harvey (George, Esq.) observations on some phenomena, relating to
the formation of dew on metallic surfaces, 1\—12. On the influ-

ence of magnetism on chronometers, 179—202, 365—367. Ex-

_ perimental inquiries by, relative to the distribution and changes
of the magnetic intensity in ships of war, 261, 262.

Harwood (Dr.) syllabus of his lectures on zoology, 286

Hatching of fish, Chinese method of, 178

Hayotte, advancement of the ground in the village of, 180, 181

Henry (Dr.) remarks on the review of his Elements of Chemistry, in
this journal, 131—134. On the action of finely-divided platinum
on gaseous mixtures, and its application to, 277, 278

Herschel (J. F.) analysis of the Bakerian lecture by, 256—259

Herschel (J. F.) and South (James) observations by, on the apparent
distances and positions of certain double stars, 250—253 ;

Hill (Mr. P.) particulars by, relating to the ornithorhynchus paras
doxus, 247—250

Home (Sir Everard,) facts by, relative to the natural history of
the walrus and seal, 262, 263. Account of the organs of gene+
ration of the Mexican Proteus in a developed state, 278, 279

Hume (Mr.,) notice of his discovery of anew vegeto-ralkaline base,
in Jalap, 386

Hydrogen Gas, odour of, extraneous, 380

Hydrogen, (sulphuretted,) preparation of, 164. Inflammation of,

by nitrie acid, 379

Hydro-sulphuret of potash, preparation of, 165

Hysterical Patient, eflect of the injection of a solution of opium
into the veins of, 145, 146

Ice-caves, natural, account of, 396

Immobility, a disease of horses, cause of, 145

Insects, solution for destroying, 146

Intermittents, prussiate of iron a remedy for, 145

Todine discovered in mineral waters, 180

Tron; action of sulphur on, 165. Experiments and observations on
the developement of magnetical propertics in, by percussion,

404 INDEX.

254, 255. Combustion of, by sulphur, 381. Ammonia found
in the oxides of iron, ibid. On the different masses of iron
found in the eastern Cordillera of the Andes, 394, 395

Tron-wire suspension bridges, remarks on, 147, Expense of the
bridge at Geneva, 148

Irritability of plants, 176

Jalap, a new vegetable principle discovered in, 38600

Just (Dr.) results of the experiments of, on fulminating silver and
mercury, 153—157

Kermes mineral, preparation of, 165

Lamp-furnace for the analysis of organic bodies, 232—235

Lampyrides, inquiry into the nature of the luminous power of
some, 269, 270

Larva, account of an undescribed species of, 176—178

Lassigne (M.) experiments of, on the oxides of nickel, 140. On
the detection of the acetate of morphia, in poisoning, 168—170

Latitude, easy approximation to the difference of, on a spheroid,
316, 317

Lecanu and Serbal, (MM.), on the preparation of oxide of uranium,
139. Collection of facts by, on the history of the succiniic and
benzoic acids, 14] v

Leeson (Mr. H. B.), description of a self-acting blow-pipe, 236

Leghorn straw-plat, premiums for, 153

Leyden Jar, improvement in the construction of, 162

Liebeg (Dr.) experiments of, on fulminating silver and mercury,
153—157 ; and on fulminic acid and fulminates, 386—390

Limestone, experiments on the burning of, 361—363

London, observations on the climate of, 340—345. Table of the
level in, above the highest water mark, 361

Longitude of Madeira and Falmouth determined, 270, 271

Mac Culloch (Dr.,) hints by, on the possibility of changing the re-
sidence of certain fishes from salt-water to fresh, 209—231

Magendie (M.) on some recent discoveries relative to the nervous
system, 143, 144,

Magnetism, on the apparent, of metallic titanium, 129. Supposed
effect of magnetism on crystallization, 158. On thermo-mag-
netism, 158—160. Influence of magnetism on chronometers, 197
—202, and 365—367. Experimental inquiries relative to the
distribution and changes of the magnetic intensity in ships of
war, 261, 262. New phenomena caused by the effects of mag-
netic influence, 276. Memoir on the theory of magnetism,
317—334.

Mechanical Science, Miscellaneous Intelligence in, 147—153,
360—369

Meconic Acid, action of, on the animal economy, 393, 394

Melania Setosa, a new species of fresh-water shell, description of,
13—15 ;

CONTENTS. 405.

Mercury (fulminating) results of experiments on, 153—157

Metallic Surfaces, observations on some phenomena relating to the
formation of dew on, 1—12

Metals, experiments on the property which some metals possess of
facilitating the comination of elastic fluids, 138, 139

Meteorological Diary for December 1823, and January and Feb-
ruary 1824, 187. For March, April, and May, 398

Metzger (M.) improvements by, in the construction of electrical
machines, 161, 162

Microscopes, observations on the indistinctness of vision caused in,
by false lights ; and on the remedies for it, 202—209. On the
adaptation of a compound microscope, to act as a dynameter for
telescopes, 367—369

Milzinsky (Count,) account of an undescribed lava, which preys
on snails, 176—178.

Mineral Waters, presence of iodine discovered in, 180

Minerals (new,) found in Mount Vesuvius, 180

Mitra, description of several pieces of, 34—38

Mole and Van Beck(Drs.) experiments by, on the velocity of sand, 266

Morphia, detection of, in cases of poisoning, 118

Morphium, test for, 170

Muriatic Acid, existence of free, in the stomach, 181

Nails,experiments on the adhesion of, when driven into different
kinds of wood, 360

Natural History, Miscellaneous Intelligence in, 175—183, 392—
397

Nautical Eye-tube, notice of, 153

Needle (horizontal and dipping,) observations on the daily varia-
tion of, 128, 129

Nervous System, recent discoveries relative to, 143, 144

Nickel, experiments on the oxides of, 140

Olbers (Dr.) remarks on the catalogue of the orbits of the comets,
that have hitherto been computed, 85—96.

Opium, effects of the solutions of, when injected into an hysterical
patient, 145—146. ’

Optic Nerves, observations on semi-decussation of, 259—261.

Optical Instruments, on the indistinctness of vision caused on, by
false lights, and remedies for it, 17—28, 202—209

Ornithorhynchus Paradoxus, some particulars respecting, 247—250

Oxide of uranium, preparation of, 136, 382. Of nickel, experi-
ments on, 140

Parallax of « Lyre, remarks on, 264, 265

Phenomena, relating to the formation of dew on metallic surfaces,
observations on, 1—12

Phillips(Mr.) on the detection of arsenic in various cases of poison-
ing, 167. Analysis of his translation of the London Pharmaco-
peia, with remarks, 349—359

406. INDEX.

Phosphorescence, connexion of, with electricity, 163. _Phosphores«
cence of acetate of lime, 163

Platinum, action of, when finely divided, on gaseous mixtures, and

its application to their analysis, 277, 278. ee

Pneumatic- Thorax, remarks ,on a case of, 130, 263

Poisoning by arsenic, tests for detecting, 167. Poisoning by the
acetate of morphia, how detected, 168—170

Poisson, (M.) extract of his memoir on the theory of magnetism,
317—334

Pond, (John, Esq.) on certain changes in the principal fixed stars,
130

Potash, preparation of the saturated hydro-sulphuret of, 165. Crys-
tallization of the sub-carbonate of, 167. Acid tartaro-sulphate of,
171

Prevost (Dr.) observations by, on the generation of fishes, 277

Prout (Dr.) on the existence of free muriatic acid in the stomach,
181

Prussiate of Iron, a cure for intermittents, 145

Pyro-ligneous ether, or pyrocilic spirit, preparation and analysis of,
171—173 . : "

Refraction, comparison of the new tables of, with observation on
astronomical refractions, 130

Revero and Boussingoull (MM.) account by, of the different masses
of irpn, found on the eastern Cordillera of the Andes, 394, 395

Royal Society, analysis of the translations of, 122—130. Account
of its proceedings, 250—280

Royal Institution, proceedings of, in 1824, 281. Syllabus of the
various courses delivered there, 282—289, List of its officers,
282,290. Terms of admission, 291, 292. Report of the visi-
ters, 292—294.

Ruby-glass (ancient) composition of, 167

Sabine (Captain), on the temperature at considerable depths of the
Caribbean Sea, 126. Comparison of barometrical measurement
with the trigonometrical determination of a height at Spitzber-
gen, 268, 269

Sand-drigs, observations on, 181—183

Scientific Books, analysis of, 105—130, 335—359 ‘

Scoresby (William, Esq.) general results of observations by, on the
dipping needle, 104. Experiments and observations on the de-
velopement of magnetical properties in steel and iron by per-
cussion, 254, 255

Scott, (H. Esq.) particulars by, respecting the ornithorhynchus
paradoxus, 247—250

Sea, (Caribbean), temperature of, at considerable depth, 126

Seal, fact in the natural history of, 263. 3

Shells, two new species of fresh-water, described, 13—17. The

INDEX. 407

_ characters of several new shells belonging to the Linnzean volute,
28—38

Ships, the copper sheeting of, how prevented from becoming cor-
roded by the action of sea-water, 253, 279, 280. Experimental
inquiries relative to the distribution and changes of the magnetic

_ intensity in ships of war, 261, 262

Silver, (fulminating), results of experiments on, 153—157

Snails, account of an undescribed larva, which preys on, 176—178

Soda, preparation of the saturated hydro-sulphuret of, 165

Sodous Acid, analysis of, 381, 382

Sound, produced by opening a subterraneous gallery, 152. Ex-
periments on the velocity of, 266

South (James, Esq.) tables of astronomical phenomena computed

_ by, from April to June 1824, 77—84. See Herschel

Stars, observations on the apparent distances. and portions of cer-

. tain double and triple, 250—253

Steel, observations and experiments on the developement of mag-
netical properties in, by percussion, 254, 255. Experiments
on the elasticity and strength of hard and soft steel, 267, 268.

Stomach, existence of free muriatic acid in, 181

Straw-plat, premiums for, 153 ;

Strychnia, process for obtaining salts of, 170. Volatility of the

_ salts of, zbed., 171

Sulphate of copper, an excellent remedy in croup, 181

Sulphur, action of, on iron, 165

Sulphurous Acid, liquefaction of, 391 ‘

Sulphuretted hydrogen, preparation of, 165. Inflammation of, by
nitric acid, 380

Swainson (Wm., Esq.) description by, of two new fresh-water
shells, 13—-17. On the characters of several new shells be-
longing to the Linnean Volute, 31—38. Remarks on the pre-
seut state of conchology, 29, 30

Tartaro-sulphate of potash, 171

Taschium, a supposed new metal, notice of, 390

Taste, organs of, how affected by different bodies, 392, 393

Taylorian Theorem, demonstration of, 74—76

Telescopes, on the indistinctness of vision caused in, by the pre-
sence of false lights ; and remedies for it, 17—28

Temperature of the sea, at various depths, 126. Effects of tem-
perature on the intensity of magnetic forces, 279

Thames, design by Mr. Ware, for making a public road under,
62—65. Notice of other tunnels, attempted or proposed,
66—69.

Thomson (Dr.) table of atomic weights by, 383

Tiark’s (Dr.) longitude of Madeira and Falmouth determined by,
270, 271

Tides, extracts relating to the theory of, 295—315

408 ENDER.

Time, indicated by any number of chronometers, an easy method
of comparing, with the given time at a certain station, 316, 316.

Titanium (Metallic), on the appa ent magnetism of, 129

Todd (Dr.) inquiry into the nature of the luminous power of some
of the lampyrides, 269, 270

Tredgold (Mr.) analysis of his work on the strength of cast iron
and other metals, 150, 151. Account of his experiments on
the elasticity of hard and soft steel, 267, 268

Unio Gigas, a new species of fresh-water-shell, description of,
15—17 .

Univalves, remarks on, 272, 273

Uranium, preparation of the oxide of, 139, 140—382. Notice
of uranium pyrophori, 383

Variation, daily, of the horizontal and dipping-needle, under a
reduced directive power, 128

Vauquelin (M.) experiments of, on the acetates of copper, 383

Vegetation, table of, at different heights, 176

Velocity of sound, experiments on, 266

Verdigris, observations on, 384 ©

Vesuvius, notice of new minerals found in, 180

Vicat (M.) experiments of, on the burning of limestone, 361—363

Violine, notice of a new vegeto-alkaline, 385, 386

Vision, on the indistinctness of, in optical instruments, and re-
medies‘for it, 17—28, 202—209

Voltaic Troughs of Dr. Hare, notice of, 378

Volute, characters of several new shells belonging to the order of,
31—38

Walker (Mr.) syllabus of his lectures on plane geometry, 285

Walrus, new fact in the natural history of, 262

Ware (Samuel, Esq.) design by, for making a public road under
the Thames, with observations, 62—69 —

Weill, overflowing, at Chiswick, account of, 70—74 —

Wollaston (Dr. W. H.) observation of, on the apparent magnetism
of metallic titanium, 129. On semi-decussation of the optic
nerves, 259—261. On the apparent direction of the eyes in a
portrait, 274—276

Young (Dr. Thomas) a finite and exact expression by, for the
refraction of an atmosphere nearly resembling the earth, 255.

Printed by WILLIAM CLOWES
Northumberland-court.

Plate 1. Vol.XVI.

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Focus 2In.

Published by John Murray. Albemurle Street Londen Big

J? Basire se,

Llate IM. VOL. XVIH.

7)

Llete IN VOL AVI.

DESIGN jr makig)2 ROADWAY under th THAMES,

fiom the east side of the Tower nex Irongate Stairs, w the opposite stde near Horstvdown Stairs

South

To the Lower Depttord Road bc

Prem the Minories and Teaver Z
porn t eres and Tower Hill dhdeng et &

=.

Lon Water

LONGITUDINAL | SECTION , ARCHWAY

HORSERXDOWN STARS WE — HORSELYDOWN LANE

ving &: the Docks

Buildings not disturbed

To Hayy

Frame. the 7 -
rm. the Mines, 2
“Ores and Tower Hyp

Tl teoncare stains
FREEMANS LANE

Grout for Butldings

22UDLLUT

RMER THAME

suey wnopApos

al
a

{ North
Grou for Puildings Ground tor Buildings

South

Bupunse — pooy

Koad ascending to Fro"

Building s

Greund for
Buildings

Slope

Lehi
Warehouses
not dishabedl

Tom, to ok

PLAN of © ARCHWAY and tr APPROACHES.

Scale
NB. Sn the dav time the Archway will be

sullictenily lighted from the ends.

The yround required tor this approach

Pre verte wip frome the

belongs wholly to the Tower
High water _

Low water

Bed of the River:

ELEVATION Of the ENTRANCE
atA

TRANSVERSE SECTION of the ARCHWAY.

TF Bane om.

(apne 2asog sump

PEG UCPUCT "WAC mwvumapy ADL Wor Ag PEYSRGRL

if EET

60m / aq ego yas: as hapa A ¥2
a coe

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