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i' kU I

GENERAL SCIENCE,

BY

ROBERT D. THOMSON, M. D.,

PHYSICIAN TO THE FORE STREET DISPENSARY, CRIPPLEGATE, AND LECTURER ON
CHEMISTRY IN THE BLENHEIM STREET MEDICAL SCHOOL.

WITH THE ASSISTANCE OF

THOMAS THOMSON, M.D., F.R.S.L. &E., F.L.S.,F.G.S.,&c.

REGIUS PROFESSOR OF CHEMISTRY IN THE UNIVERSITY OF GLASGOW.

VOL. IL

LONDON:

JOHN TAYLOR, 30, I/PPER GOWER STREET,

Bookseller and Publisher to the University of London ; and

st)ld by maclachlan and stewart, edinburgh ; john reid and co., and ruther-

glen and co., glasgow ; w. curry jun., and co., and robertson and co.,

dublin ; king and co., cork ; grapel, liverpool ; webb and sims,

manchrster; and barlow, Birmingham.

1835.

TABLE OF CONTENTS.

No. Yll.—July 1835.

Page

I. Fairy Stones 1

II. On Urine. By Thomas Thomson, M. D., &c. . . • 3

III. Examination of Lymph, Blood and Chyle. By John

Miiller, M. D., &c. Continued 15

IV. On Accidental and Complementary Colours. By Charles

Tomlinson, Esq 21

V. On the Number and Character of the Colours that enter

into the Composition of White Light. By P. C. . . 27

VI. On the Relation of the Specific Heat of Bodies to their

Atomic Weights 34

VI. Ascent of Chimborazo on the 16th December 1831. By

M. Boussiugault 45

VII. Examination of Hair Salt, or Native Sulphate of Alu-

mina and Iron. By Robert D. Thomson, M. D. . . 55

VIII. Observations on the Formation and Changes of the In-
ferior Order of Plants. By F. J. Kutzing .... 62

IX. Analyses of Books 64

1. Introduction a Tetude de la Botanique ou Traite Ele-

mentaire de cette Science. Par Alphonse de Candolle ib.

2. Memoir on the Fresh Water Formation of Burdie-

house, &c. By Samuel Hibbert, M. D., &c. . . 68

X. Scientific Intelligence 71

1. Royal Institution. Dr. Faraday on Sound . ... ib.

2. Diseases of the Larch 72

3. Arsenic in English Sulphuric acid 73

4. American Patents 76

5. New Method of Drying Plants 74

6. Flora of the Arkansas ib.

7. F. P. N. Gillet de Laumont 75

8. Severity of Last Winter in America 7^

9. New Cetaceous Animal ib.

10. Combinations of Iodine with Palladium and Iridium . 77

11. VolvoxGlobatorof Miiller 78

12. Capnomore 79

13. Iron Works in the Uralian District ib.

Meteorological Table 80

No. Ylll.— August.

I. Biographical Account of Baron Dupuytren, with a Portrait 81

II. On Racemic Acid. By Thomas Thomson, M. D., &c. . . 97

III. On the Number and Character of the Colours that enterinto

the Composition of White Light By P. C, continued. 108

IV. Instances of Spontaneous Combustion, detailed in a paper

read before the Royal Irish Academy, 25th IVIay, 1835.

By M. Scanlan, Esq 119

V. On an easy Method of Measuring Prismatic Spectra. By

Mr. Andrew Pritchard 122

a

IV CONTENTS.

PAGE

V I. Experiments and Observations on Visible Vibration. By

Charles Tomlinson, Esq., continued 124

VII. Pdrification of Pyroligneous Acid and Manufacture of

Acetate of Lime according to the Method adopted by
Chemical Manufacturers. By Chr. Phil. PrUckner of Hoff 133

VIII. Analyses of Books 142

1. Optical Investigations By G. H. S. Johnson, M. A. . ib.
Optical Investigation ; Caustics. By the Same . . . ib.

2. Coloured Impressions of Engravings from the Natural
History of Animalcules. By Andrew Pritchard, Esq.
London, 1835 143

3. On the Action of Voltaic Electricity, on Alcohol, Ether,
and aqueous Solution By Arthur Council, Esq. . . ib.

IX. Scientific Intelligence 145

1. Proceedings of the Ashmolean Society of Oxford . . ib.

2. Application of Hot Air in the Smelting of Iron . . .151

3. Action of Muriate of Ammonia upon some Sulphates
and upon Silver 152

4. Phosphate of Quinine 153

5. Pectic Acid ib.

6. Cases of Poisoning in France '. 154

7. Dilatation of the Metals by Heat ib.

8. Aldeide, and a New Acid 155

9. On the Evaporation of Charae ib.

10. Composition of Goat Fat 156

11. Chemical Nature of the Secretions .... , . ib.

12. Esculic Acid 158

13. New Yellow Dye for Wool ib.

14. Horary Observations of the Barometer. &c. for 36 hours

on the 22d and 23d of June last. By the Rev. John Wallace 159

15. Meteorological Journal for June. By Ditto . . . 160

No. IX. — September.

I. On Racemic Acid. By Thomas Thomson, M. D., continued 161

II. On the Number and Character of the Colours that enter into

the Composition of White light. By P. C, continued 172

III. Proceedings of the British Association for the Advancement

of Science 186

1. Section of Geology and Geography 188

2. Ditto Chemistry and Mineralogy 195

3. Ditto Mathematics and Physics 206

4. Subsection of Mechanical Science applied to the Arts . 219

5. General Meetings 224

6. Address of Professor Hamilton ib.

7. Dr. Lardner on Steam Carriages 230

8. Professor Powell on the theory of the dispersion of light 232

9. Mr. Whewell on the phenomena of the Tides . . . 233

10. Professor Babbage on the age of Peat Mosses . . . ib.

11. Speech of the Rev. Vernon Harcourt ib.

12. Professor Babbage on a Whirlpool at Cephalonia . . 235

IV. Scientific Intelligence 236

1. Live Toad found embedded in Stone, By A. Pollock Esq. ib.

(

CONTENTS. V

PAGE

2. Scientific Association of Germany 237

3. Remarks on the temperature of the Baltic. Extract of

a Letter from Alexander Humboldt ih.

Meteorological Journal. By the Rev. John Wallace . 238

No. X.— October.

I. On Racemic Acid, (concluded). By Thomas Thomson,

M. D., F. R. S., &c 242

II. Ascent of Chiraborazo, on the l6th December, 1831. By

M. Boussingault, co/icZwc^t'o? . 252

III. Researches into the Nature of the decolourizing combi-

nations of Chlorine. By A. J. Balard ...... 262

IV. On the Rocks which are distinguished by the names of

Greenstone and Greenstone Porphyry. By Gustav Rose 272

V. On the Phenomena of Accidental Colours. By M. Plateau.

(Abridged from the Annales de Chimie et de Physique,
liii. By Charles Tomlinson, Esq.) 281

VI. On the Theory of Accidental and Complementary Colours,

with additional Experiments and Observations. By
Charles Tomlinson, Esq 283

VII. On Malt. By Robert D. Thomson, M. D., concluded . 295

VIII. Analyses of Books.

The Transactions of the Linnean Society of London, vol.
xvi. part ii. 1835 304

IX. Scientific Intelligence.

1. British Association — Anatomy and Medicine . . . 309

Botany and Zoology 311

Statistics 312

2. Anatase, Napthaline, Bi-calcareo-Carbonate of Barytes,
Chemical Symbols 314

3. Blue Velvet Copper 315

4. Paramorphine and Pseudo-Morphine 3l6

5. Massy Iridium. By Gustav Rose 3l7

6. Remarkable Flight of a Bird 3 18

7. Black Mud from Common Sewers ib.

8. Gums 319

9. Meteorological Journal. By the Rev. John Wallace . 320

No. XI. — November.

I. Life of the Rev. John Flamsteed, First Astronomer- Royal.

Written by himself _..... 321

II. Researches into the Nature of the decolourizing combina-

tions of Chlorine. By A. J. Balard, continued . . . 341

III. On the number and character of the Colours that enter

into the composition of white Light. By P. C, continued 351

IV. The Action of Saline Solutions upon Fibrin. By Harry

Rainy, M. D., Lecturer on the Theory of Physic, in the
University of Glasgow, in a Letter to the Editor . . 365

V. On the Sesquisulphate of Manganese. By Thomas Thomson,

M.D. &c. Regius Professor of Chemistry in the Univer-
sity of Glasgow .... 369

VI CONTENTS.

PAGE

VI. Animal Heat 371

VII. Pyroxylic Spirit and its Compounds 374

VIII. Analysis of Opium 380

IX. Analysis of Books 383

1. Poggendorff's Annalen der Physik und Chemie . . . ib.

2. Philosophical Transactions of the Royal Society of Lon-
don for 1835. Part i , 388

3. Manual of Pathology, &c. By L. Martinet, D. M. P.
Translated by Jones Quain, M. D 390

X. Scientific Intelligence 391

1 Excise Committee of the Royal Society ib.

2. Passage of Electricity through Liquids 303

3. Wichtine 397

4. Taraxacum Officinale ib.

5. Plants of Arabia, Palestine and Egypt 398

6. Chloride of Gold as a caustic ib.

7. Ink permanent in the Air ib.

Horary Observations of the Barometer^ Thermometer &c. 399
Meteorological Journal , . . . , 400

No. XII. — December.

I. Life of the Rev. John Flamsteed, First Astronomer- Royal.

Written by himself, continued 401

II. Researches into the Nature of the decolourizing combina-

tions of Chlorine. By A. J. Balard, concluded . . 425

III. On Bleaching Powder. By Thomas Thomson, M. D. &c.

Regius Professor of Chemistry in the Univfersity of
Glasgow , 435

IV. An Easy Method of filling Barometers. By a Correspondent 440

V. On the Rocks which are distinguished by the Names of

Greenstone and Greenstone Porphyry. By G. Rose . 444

VI. On Madder and Madder Dyeing 452

VII. An Account of the process of making Spirits in Great

Britain and Ireland 457

VIII. Analyses of Books 465

1. Philosophical Transactions of the Royal Society of
London for 1835. Part i ib.

2. New Works 47O

Lehrbuch der Geologie und Geognesie von Dr. R. C.

von Leonhard. 1834 ib.

Lehrbuch der Botanik von Dr. G. M. Bischoff , . . ib.

3. Resolutio Problematis de circuli Quadratura juxta cal-
culum quem colligere potuit Joaquimus Antonius de
Oleivera Leita6 471

IX. Scientific Intelligence ib.

L Natureof the Combinations of Alkalies with Carbonic Acid ib.

2. Pharmaceutical Preparations 474

3. Statistics of Geneva 475

4. On Chemical Symbols 476

5. Weather at Madras . ^ 479

6. Meteorological Journal 480

RECORDS

OF

GENERAL SCIENCE

JULY, 1835.

Article I.
Fairy Stones.

During the course of last summer, while exploring the
fertile valley of the Tweed, in the vicinity of Melrose, the
Editor was presented, by an esteemed friend, with a number
of little rounded pieces of stone, of which the accompanying
wood-cut is intended to form a full size representation. They
are denominated by the common people fairy stones, from
a tradition that the locality from which they are derived
was the residence of the fairies. They consist of a calca-
reous schist, which has been broken down and fashioned
into the regular forms delineated, by the influence of the
current. Analysis gave

Carbonate of lime . . . 58'5
Schistose matter . . . . 41*5

100-

Many of them possess a border as if they had been turned
by a lathe, and exhibit sculptures on their surface resem-
bling oriental letters.

Sir Walter Scott, in the introduction to the Monastery,
has alluded to these curious fragments, and has described

VOL. II. - B

2 . Fairy Stones. [July

the glen where they are found, and its neighbourhood, so
well, that no apology is necessary for introducing the
following extract: Opposite to Melrose " might be seen
the remains of ancient enclosures, surrounded by sycamores
and ash trees of considerable size. These had once formed
the crofts or arable ground of a village, now reduced to a
single hut, the abode of a fisherman, who also manages a
ferry. The cottages, even the church which once existed
there, have sunk into vestiges hardly to be traced without
visiting the spot, the inhabitants having gradually with-
drawn to the more prosperous town of Galashiels, which
has risen into consideration within two miles of their
neighbourhood. Superstitious eld, however, has tenanted
the deserted graves with aerial beings, to supply the want
of the mortal tenants who have deserted it.

'* The ruined and abandoned churchyard of Boldside has
been long believed to be haunted by the fairies, and the
deep broad current of the Tweed, wheeling in moonlight
round the foot of the steep bank, with the number of trees
originally planted for shelter round the fields of the
cottagers, but now presenting the effect of scattered and
detached groves, form a scene which Oberon and Queen
Mab might love to rev^l in."

" Another and more familiar refuge of the elfin race (if
tradition is to be trusted) is the glen of the river or rather
brook named the Allen which falls into the Tweed, from
the northward about a quarter of a mile above the present
bridge. As the streamlet finds its way behind Lord
Somerville's hunting seat, called the Pavilion, its valley has
been popularly termed the Fairy Dean, or rather the Name-
less Dean, because of the supposed ill luck attached by the
popular faith of ancient times, to any one who might name
or allude to the race, whom our fathers distinguished as the
Good Neighbours, and the Highlanders called Daoine Shie,
or Men of Peace ; rather by way of compliment than on
account of any particular idea of friendship.

" In evidence of the actual operations of the fairy people,
even at this time, little pieces of calcareous matter are found
in the glen after a flood, which either the labours of these
tiny artists, or the eddies of the brook among the stones,
have formed into a fantastic resemblance of cups, saucers,

1835,] on Urine, 3

basins, and the like, in which children who gather them
pretend to discern fairy utensils." The streamlet is *' after
traversing the romantic ravine called the Nameless Dean,
thrown off from side to side alternately, like a billiard ball
repelled by the sides of the table on which it has been
played."

Article II.

Oh Urine, By Thomas Thomson, M.D., F.R.S. L. & E.,
&c., Regius Professor of Chemistry in the University of
Glasgow.

Human urine when newly emitted has usually a yellow
colour and is perfectly transparent. It is said that when
allowed to stand in a glass, it gradually deposits a small
quantity of mucous sediment. But I have been able to
observe this only occasionally, when in all probability the
secretion of mucus had been increased by some circumstance
or other. In certain diseases of the bladder, the quantity of
mucus in urine is very considerable, and it occasionally
puts on an appearance so like pus that the diagnosis is very
difficult.

Urine newly emitted has a very distinct aromatic smell,
which has been compared to that of violets. When it cools
the aromatic odour leaves it and is succeeded by another
well known by the name of urinous. This odour is in two
or three days succeeded usually by another, which has
considerable resemblance to that of sour milk. This smell
gradually disappears in its turn and is succeeded by a fetid
ammoniacal odour.

Urine has a disagreeable bitter saline taste of very
various degrees of intensity. Sometimes so slight that it
can barely be distinguished from that of water. In such
cases it is nearly colourless. When urine is high coloured
its taste is always strong.

Nothing is more variable than the colour of urine. The
most common colour is yellow of various shades ; some-
times it passes into orange or even into red. It is said to
be deeper in men than in women, but I have not been able
to satisfy myself that any such difference exists. There is

B 2

4 Dr, Thomas Thomson [July

an intimate connexion between the depth of the colour and
the quantity emitted. When the urine is scanty it is al-
ways deeply coloured. Hence the reason of the red colour
of urine in fevers. When the quantity emitted is great the
colour is pale. I have seen it in cases of hysteria so nearly
colourless and tasteless, that it was only by concentration
I was able to satisfy myself that it contained the usual con-
stituents of urine. When such urine is concentrated it
gradually acquires the usual yellow colour of urine, and
this colour deepens into red when the concentration is
pushed far enough. Sometimes urine contains bile, and
then its colour is orange yellow. The presence of bile is
easily detected by pouring a little muriatic acid into the
urine suspected to contain it. If any be present the colour
immediately changes into green.

Occasionally the colour of urine is so deep that it appears
almost black ; this is sometimes owing to a mixture of blood,
but sometimes it is produced by the substances taken into
the stomach. Thus, when preparations of iron are given at
the same time with rhubarb, the urine is said to assume a
blackish colour. Urine has frequently a red colour, and the
shade varies from rose red to scarlet. Red urine commonly
characterizes an inflammatory state of the system. Such
urine is always scanty. What the colouring matter is to
which it owes its particular tint has not been ascertained.

Other colours of urine are mentioned by medical men ;
thus it has been described as greyish, greenish, and buff
coloured. Dr. Prout mentions a case in which it threw up
a cream like milk ; such urine might be called white, and
it doubtless owes its peculiar qualities to the presence of
chyle.

The smell of urine is altered by various causes apparently
trifling. Asparagus gives it a peculiar fetid odour, while a
little oil of turpentine taken into the stomach, very soon
communicates to the urine the smell of violets. In many
individuals almost every article of food produces a corre-
sponding change on the odour of the urine. In the disease
called diabetes, the urine has a smell quite different from
that of common urine ; but not easily described ; I would
call it sweetish.

The specific gravity of the lightest urine that ever came

1835.] on Urine. 5

under my observation was 1.000148; that of the heaviest
1048. The former was voided by a hysterical patient,
the latter by a man labouring under confirmed diabetes.
In this disease the specific gravity of the urine has been
observed as high as 1*052. When the individual is in per-
fect health the specific gravity of the urine varies from
1-0093 to 1'0192, depending in some measure upon the
quantity of liquid taken into the stomach. The mean
specific gravity during perfect health, I have found to be
1 '013859. The highest specific gravity of urine from a
healthy individual that I ever met with was 1-0266.

The mean quantity of urine voided in 24 hours is about
3-J^lbs. avoirdupois, but it varies very much even in the
same individual, soinC'times amounting only to 2-1331bs.
and sometimes to 4-8571bs.

The colouring matter of urine has never been obtained
in a separate state ; we are consequently ignorant of its
nature. From an observation of Dr. Prout, it would seem
that urine contains two different colouring matters. When
urine is filtered through urateof ammonia, it communicates
a brown colour to that salt, but if we continue to pass the
same urine through different portions of urate of ammonia,
it at last ceases to communicate any tint to it, yet the
colour of the urine continues of as lively a yellow as ever.
Urine then it would seem contains a matter which gives a
brown colour to urate of ammonia, and another to which it
is indebted for its yellow colour.

The yellow^ colouring matter is precipitated from urine
by nitrate of silver. If we wash the precipitated matter it
appears almost black. When dilute nitric acid is poured
upon it, both the colouring matter and oxide of silver are
dissolved, and the acid assumes the colour of urine. I
have not prosecuted this experiment, though it seems to
point out a method by which the colouring matter might
be insulated. If the silver precipitate were washed and then
put into water, and a current of sulphuretted hydrogen
passed through the liquid, it is probable that the silver
would be converted into sulphuret, while the colouring
matter would dissolve in the water.

Urine when recently voided always contains an acid, at
least partly in an uncombined state; for it converts vege-

6 Dr. Thomas Thomson [July

table blues to red, and the change is permanent. Various
opinions have been formed respecting the nature of this
acid. It was supposed at first to be the phosphoric. This
was the opinion of Proust, and of Fourcroy, and Vauque-
lin. Urine contains a minute quantity of phosphate of
lime, which may be precipitated in the state of a light
white sediment by caustic ammonia. Now as phosphate of
lime is insoluble in water, while a little of it is actually
held in solution in urine, it was not unreasonable to con-
clude that the salt in urine might be in the state of biphos-
phate of lime ; as in that state it is slightly soluble in
water, and has the property of changing vegetable blues to
red. But a very simple experiment is sufficient to show
that urine contains no biphosphate of lime. If we evaporate
a quantity of urine to dryness and ignite the dry residue,
the residual salts do not act on litmus paper. Hence it is
obvious that the free acid in urine must be volatile, since
it is dissipated by a red heat.

Berzelius affirms that urine contains lactate of ammonia
and lactic acid; and to the presence of these bodies he as-
cribes the peculiar smell and colour of urine, as well as its
property of reddening vegetable blues. As I have never
been able to satisfy myself of the presence of these bodies
in urine by experiment, it is impossible to adopt Berzelius'
opinion respecting them. A brown coloured matter may
certainly be obtained from urine, but I have always got
it in such minute quantity that I was unable to determine
any thing positive respecting its nature.

Thenard has substituted acetic acid for the lactic acid of
Berzelius, probably because Fourcroy and Vauquelin had
concluded from a set of experiments made many years ago,
that lactic acid is merely acetic contaminated by or com-
bined with a little animal matter. But this position was
by no means established by their experiments. In order to
be able to form some definite notion on the subject, I
mixed sulphuric acid with fresh urine till it tasted dis-
tinctly acid, and distilled over one-third 9f the mixture
from a retort by means of a gentle heat. The liquid which
came over was tasteless and had no perceptible smell ; it
slightly but evidently reddened litmus paper. It was mixed
with carbonate of soda till it became sensibly alkaline ; be-

1835.] on Urine. t

being now evaporated to dryness, and a drop of sulphuric
acid let fall upon the small saline residue, a smell was
emitted strongly urinous, but mixed with a sensible odour
of vinegar. From this experiment I conclude that urine
does contain a minute portion of acetic acid. But it is pro-
bable that it contains also another volatile acid in small
quantity to which the peculiar odour of urine is owing,
as Berzelius supposed. Whether this acid be lactic we
have no data to decide.

Urine contains always some uric acid which separates in
minute crystals when the urine is mixed with a little nitric
acid and set aside for some time in an open glass vessel.
Berzelius states the amount of this acid in urine at y^Voth
part of the weight. By my experiments to be stated after-
wards, it appears that 1000 parts of urine of the specific
gravity 1-0185 let fall 0*242 of uric acid when mixed with
nitric acid. Now, Dr. Prout has shewn that uric acid does
not dissolve in 10,000 times its weight of water, but that
urate of ammonia is soluble in about 500 times its weight
of that liquid. Hence, he infers that the uric acid in that
liquid must be in the state of urate of ammonia. Biit urate
of ammonia reddens vegetable blues; hence, the acidity of
urine may be partly owing to the presence of this salt.

Urine is probably the most complex liquid in the animal
economy. It is obviously secreted from blood in order to
be thrown out of the system, and must, therefore, hold
in solution various substances extracted from the blood, in
order to bring that liquid into a state fit for the various
purposes of assimilation and secretion to which it is applied.
Blood consists essentially of water, holding in solution
albumen, fibrin and hematin ; it contains also minute quan-
tities of soda and perhaps of potash, partly united to albu-
men and partly to muriatic acid. It contains likewise
common salt.

The albumen seems to contain, in some state of combi-
nation, phosphorus, sulphur, and traces of calcium and
magnesium. These substaAces exist in albumen probably
because they are useful to some parts of the animal
economy. Thus they seem to be deposited in considerable
quantity in the brain, but for the other parts of the animal
body they are doubtless pernicious, and therefore are ab-

8 Dr. Thomas Thomson * [July

stracted by the kidneys and thrown out of the system.
This is brought about by making them soluble in water,
and for this purpose they are converted into phosphoric
acid, sulphuric acid, lime and magnesia, substances which
in certain states of combination are soluble in water and
consequently in urine. Uric acid is also formed and
rendered soluble by being united with ammonia. It would
seem that ammonia is also formed in the kidneys, at least
we have no evidence that it exists in the blood. The obser-
vations of Dr. Marcet confirm the previous statement of
Proust, that carbonic acid is also a frequent constituent of
urine.

The most remarkable substance in urine is the body to
which Fourcroy and Vauquelin gave the name o^ urea. It
was originally detected by Rouelle junior ; but it is chiefly
by the researches of Cruickshanks and Dr. Prout, that its
characters have been determined with accuracy. Accord-
ing to Berzelius it exists in healthy urine to the amount of
three per cent. But I have never been able to extract so
much, except in certain cases where the quantity of urea
was obviously in excess. My method was to mix the urine
with the requisite quantity of nitric acid, and concentrate
by spontaneous evaporation in a very dry and warm place
till as much nitrate of urea fell in crystals as could be got.
Weighing this precipitate and determining its solubility in
water, I calculated the portion remaining in solution in
the residual liquid ; and knowing the urea in a given weight
of this nitrate, I concluded the whole urea in the quantity
of urine operated on. By this method I extracted from
1000 grains of healthy urine of the specific gravity 1*0185,
23.64 grains of urea. I employed several other methods
but none of them gave such good results as the one just
described.

Except the acid or rather the supporter which exists
in common salt, no acid can be detected in blood, but a
trace of phosphoric. In urine, however, there are always
three acids, namely, the uric, phosphoric, and sulphuric,
and three bases, namely, lime, magnesia, and ammonia,
which cannot be demonstrated in blood. The great function
of the kidney then is the formation, or at least the separa-
tion of certain acids and bases. The acids and bases are

1835.] on Urine. , 9

formed doubtless that they may constitute soluble com-
pounds, which may be withdrawn from the blood and
thrown out of the system by the urine.

Oxalic acid is a common ingredient in urinary calculi,
always I believe united to lime ; and oxalate of lime is said
to have been observed in some rare instances deposited
from urine under the form of gravel. It is obvious from
this that it must sometimes exist in urine, and therefore be
secreted or separated from the blood in the kidneys. But
I have never myself had an opportunity of examining any
urine containing oxalic acid, nor have I even heard of any
person who had.

Small calculi composed of carbonate of lime occur some-
times though rarely in man ; but such calculi from the
inferior animals are abundant, especially from the horse
and cow. This is another reason for admitting at least
the occasional presence of carbonic acid in urine.

The analysis of urine is rather a difficult process, and
different specimens differ so much from each other, that it
is difficult to give a general view of the constituents that
may not in some cases mislead. I shall, therefore, describe
an analysis of healthy urine of the specific gravity 1*0185,
which I made some years ago. I employed in the analysis
11^ cubic inches of urine, or 2957*45 grains ; but for the
sake of clearness I have reduced the constituents to what
they would have been had I employed only 1000 grains of
the urine.

1 . The urine was mixed with caustic ammonia till it was
rendered sensibly alkaline, and left 24 hours in a covered
glass jar ; a white precipitate fell, which being collected,
washed and ignited, weighed 0*209 grains. It was phos-
phate of lime ; for it dissolved without effervescence in
nitric and muriatic acids, and was again precipitated by
caustic ammonia.

2. The residual liquid was gently heated to drive off the
ammonia and then mixed with a solution of nitrate of lime
and left as before for 24 hours in a covered glass jar. A
white precipitate fell, which being collected, washed and
ignited, weighed 2*01 grains ; it was phosphate of lime, and
indicated the presence of 1*131 grains of phosphoric acid
in the urine.

10 Dr. Thomas Thomson [July

3. The urine thus freed from lime was mixed with a little
nitrate of barytes dissolved in water ; the sulphate of barytes,
which precipitated being collected, washed and ignited,
weighed 1*3949 grains = 0*481 grains of sulphuric acid.

4. The urine thus freed from phosphoric and sulphuric
acids, was mixed with a little carbonate of ammonia to
throw down any excess of lime or barytes that might
have been added in the preceding steps of the analysis.
The sediment vras allow^ed to subside and the urine drawn
off by a sucker, and the w^ashings of the sediment being
added to the original liquid, the vrhole was exactly neutra-
lized by nitric acid. Nitrate of silver was now dropt into
it as long as chloride of silver continued to precipitate.
This precipitate after being well washed was digested in
dilute nitric acid and then dried and fused. It weighed
23*449 grains = 5'782 grains of chlorine.

5. To the whole urine thus deprived of phosphoric, sul-
phuric, and muriatic acids, such a quantity of sulphuric
acid was added as was more than sufficient to neutralize all
the bases, and consequently to displace all the nitric acid
with which they were in combination. The whole was now
evaporated to dryness, and the residue ignited in an open
platinum crucible. A white salt remained which could
only be a mixture of sulphate of potash and sulphate of
soda. It weighed 14*1326 grains.

This salt being dissolved in water, the sulphuric acid
was thrown down by chloride of barium. The sulphate of
barytes being collected, washed and ignited, weighed 21*667
grains = 7*4716 grains of sulphuric acid.

Any excess of barytes was separated by means of sulphuric
acid very cautiously added, and the liquid being evaporated
left a salt, which, after ignition, weighed 11*634 grains.
It consisted of a mixture of chlorides of potassium and
sodium. The chlorine just replaced the sulphuric acid,
and 7*4716 sulphuric acid are equivalent to 6*4677 chlorine.
Now, to find the weight of potash and soda, in these salts
we have the following data :

Weight of the sulphates . . . .14*1326
,, sulphuric acid .... 7*4716

Weight of the potash and soda . . 6*6610

1835.] on Urine. it

Weight of the chlorides ....

11.634

„ chlorine ....

6-467

Weight of the potassium and sodium

5.167

Weight of an atom potash = 6

,, soda = 4

„ potassium = 5

,, sodium = 3

Atoms of soda present = y

,, potash = X

7-4716 -f 4i/ -f 6:r = 14-1326

6-4677 + 3 V 4- 5 ^ = 11-6314

These two equations give us the two foil

owing values

of i/.

6-661 — 6 ;r
y- 4

5.1664 — 5 :r

3^ =

3

By equating these two values of y we get x = 0-3418.
Hence y = 11524.

Therefore 4 3/ or the soda = 4.61
" 6 :r or the potash = 2.051
Thus it appears that the soda in the urine is more than
twice the weight of the potash.

6. To determine the quantity of uric acid, another equal
portion of the fresh urine was mixed with a little nitric
acid, and set aside for 24 hours. The uric acid deposited
was white, or rather grey, and weighed 0*242 grs.

7. Another portion of the same urine, was mixed with
half its bulk of moderately strong potash ley, in a retort,
the beak of which was plunged into a weak solution of
nitrate of lead, and a fourth part of the liquid was distilled
off by a gentle heat. The ammonia which passed over
threw down the oxide of lead. The quantity of oxide thus
precipitated, supposing the urine employed to have been
1000 grs., would have weighed 0-856 grs., equivalent to
0'13 grs. of ammonia.

8. To determine the quantity of urea, the following
method was adopted : The portion of urine from which
the uric acid had been precipitated by means of nitric acid

\2 Dr. Thomas Thomson [July

was put under the exhausted receiver of an air pump, and
evaporated to dryness over sulphuric acid. A yellow
coloured bitter tasted matter remained, partly brittle and
partly viscid. It dissolved in water, except 0*1 gr., which
had a brown colour, and the half of which dissolved in nitric
acid.

The aqueous solution being concentrated in a low heat to
IJ cubic inch, crystals of nitrate of urea were deposited.
These were separated and dried as completely as possible
between folds of blotting paper.

It was found by experiment that at the temperature of
50° (that of the \\ cubic inch of residual liquid) 100 parts
of water dissolve 19*7 partsof nitrate of urea; consequently,
51*94 grs. of it must have remained in solution in the IJ
cubic inches of the liquid. The weight of the crystals was
3r6 grs.; so that the whole nitrate of urea from 25*64 grs.
of urine, (the quantity employed) was 83.54 grs.

To determine how much urea existed in the 83*54 grs. of
nitrate, a portion of it was dissolved in water, and the nitric
acid exactly saturated by carbonate of potash. The whole
was evaporated to dryness, and the nitrate of potash was
washed clean by alcohol and weighed. By this method it
was ascertained that nitrate of urea is a compound of

Nitric acid 6*75

Urea 17*24

The whole urea then contained in the 83*54 grs. of nitrate
was 60*04 grs. ; consequently, 1000 grs. of urine contain
23*64 grs.

The urea thus determined was not freed from colouring
matter, and had a pretty deep reddish-brown colour.

9. It may be worth while to relate another set of experi-
ments made to determine the quantity of urea in 2341 grs.
urine of the specific gravity 1*0215.

The urine was evaporated to dryness, over sulphuric acid,
in the vacuum of an air pump. The residue was a buff
coloured substance, very tough and hard, and weighing
103*4 grs. It was digested in 8 cubic inches of alcohol, of
the specific gravity 0*817 for several days. The alcohol
assumed an orange-red colour. Being decanted off the
undissolved residue, its specific gravity was found less than

1835.] on Urine. 13

0*817. Being mixed with water, the alcohol was distilled
off, and the residual liquid dried in vacuo, over sulphuric
acid. There remained 61*1 grs. of urea and colouring
matter. On the undissolved residue 3 cubic inches of the
same alcohol were digested for several days, and then
decanted off. It acquired a light shade of greenish-yellow,
and the specific gravity had become 0*832. It was found
to contain in solution 14*25 grs. of matter; 10*44 grs. of
which were salts of urine, and 3*81 grs. urea and colouring
matter.

Thus, the whole urea and colouring matter amounted to
64*91 grs. from 23*41 grs. of urine. Hence, 1000 grs. would
have yielded 27*6 grs. This is almost 4 grains more than
was obtained when nitric acid was employed. The reason
of this is that the second specimen of urine had a higher
specific gravity than the first.

The constituents obtained from 1000 grs. of urine of the
specific gravity 1*0185, by the preceding analysis, are the
following : — grains.

Phosphate of lime 0*209

Phosphoric acid ...... 1*131

Sulphuric acid 0*481

Chlorine 5*782

Uric acid . 0*242

Soda . 4-610

Potash 2*051

Ammonia 0*130

Urea and colouring matter . . 23*640

38*276
It is obvious that the bases and acids in urine are in
combination, constituting salts. If we compare the atomic
weights of the acids and bases present, it will be found that
there is a slight excess of bases. But as, in fact, there is
an excess of acid in urine, and as we have shewn it to
contain acetic acid, and another volatile acid with a urinous
smell, we must add to the constituents obtained as much
acetic acid as will saturate the excess.

I consider the probable saline constituents of urine to be
as follows :

14 Dr. Thomas Thomson putY

Urate of ammonia 0*298

Sal-ammoniac 0*459

Sulphate of potash 2-112

Chloride of potassium .... 3*674

Chloride of sodium 15*060

Phosphate of soda 4*267

Phosphate of lime .... 0*209

Acetate of soda 2*770

Urea with colouring matter . . 23*640

42-489

Such, by my analysis, are the constituents of healthy
urine of the specific gravity 1*0185. The mucus which may
occasionally be seen in it in very minute quantity has been
omitted, because it is a secretion of the mucus membranes
through which that liquid passes, and does not belong to
the urine itself.

The only other analysis of urine is that of Berzelius,
made almost thirty years ago, which differs very much
from mine. Berzelius does not give us the specific gravity
of the urine which he employed. But certainly it was not
healthy urine ; for he states that it became quite turbid on
cooling, which healthy urine does not do.

I have analysed specimens of healthy urine of various
specific gravities, from 1*01 to 1*021, and have obtained
nearly the same ratios of the constituents as in the pre-
ceding analysis. All the individuals whose urine I examined
inhabited the west of Scotland. It would be interesting to
have the analysis of urine from individuals living in different
countries, and supported by different kinds of food, that we
might ascertain whether the above ratios be constant, or
whether, as is most likely, they would vary with the climate
and the food.

Proust affirms that recently emitted urine contains
carbonic acid gas, and that its escape occasions the frothing
which always appears during the evaporation of urine.
Vogel assures us, that he put a quantity of fresh urine into
a phial from which there passed a tube which sunk to the
bottom of a vessel filled with lime water. The whole of
this apparatus being put under the receiver of an air pump,
and the air exhausted, air bubbles rose from the urine,

1835.J on Urine, 16

which passing through the lime water, rendered it milky.
Thus shewing the evolution of carbonic acid gas from the
urine.

I repeated this experiment of Vogel several times, em-
ploying healthy urine recently voided and still warm. The
urine frothed a good deal and emitted air bubbles, but the
lime water remained perfectly transparent during the whole
process, shewing that no carbonic acid gas was emitted.

When fresh urine is mixed with lime water, an imme-
diate precipitate of white flocks may be observed. When
these are collected, washed and dried without exposure to
the atmosphere, so as to prevent any excess of lime water
that may be present, from being thrown down by carbonic
acid, they will be found to consist of pure phosphate of
lime, for they dissolve in dilute nitric acid without any
effervescence, and the solution is again precipitated in
flocks by ammonia.

It is obvious from these facts which I have often verified,
that recent healthy urine in general contains no sensible
quantity of carbonic acid or alkaline carbonate. But from
the experiments of Dr. Marcet, it is obvious that in a cer-
tain state of the body, the urine contains carbonic acid at
the instant that it is emitted. For he found upon some
occasions, that urine when warm, when under the ex-
hausted receiver of an air pump, gave out a gas which
rendered lime water turbid, while at other times the gas
evolved, did not in the least alter the transparency of lime
water. This has been the case in all my trials, but Vogel
and Marcet found it different in their experiments. We
may conclude then that carbonic acid is an occasional but
not a constant constituent of urine.

Article III.

Examination af Lymph, Blood and Chyle. By John Mullbr,

M.D. Professor of Physiology in the University of Bonn.

(continued f 7' om vol. i. p. 433. J

Prevost and Dumas have found more globules in arterial
than in veinous blood, and also more red coagulum, and
Mayer has confirmed their results. Muller obtained from
1392 grs. of blood from the jugular vein of a goat 5 J grs.

16 Dr. John Mailer's Examination of [July

of fibrin, while 3004 grs. of blood from the carotid artery
left 14^ grs. of fibrin. The arterial blood of the goat,
consequently, contains 0*483, and the veinous blood 0*395
per cent, of dissolved fibrin. The composition of the
nuclei is still a matter of uncertainty. They possess the
characters, in a chemical point of view, common to coagu-
lated fibrin, and to coagulated albumen, for they dissolve
easily in alkalies, and with diflftculty in acids. When kept
in contact with acetic acid for a day they are not altered,
although acetic acid takes up some fibrin pretty readily.
In the same acid the globules of the frog's blood are con-
verted into a brown powder, which, when microscopically
examined, is observed to consist of the nuclei, with some of
the colouring matter adhering, while fibrin becomes opales-
cent in acetic acid.

Prevost, Dumas, and Edwards, consider the nuclei of
the globules as the elements of the muscular fibres, be-
cause they state that the muscular and nervous fibres,
according to their observations, consist of aggregated
globules. Neither Miiller, however, nor C. A. Schultze,
could detect under the microscope, globules in the muscular
fibres. The former states, that in the glitter of sun-shine,
globules may be seen, as in every texture, but undistin-
guishable from the unequality of surface, which is apparent
in the nerves and muscles. With regard to the brain and
spinal marrow, Miiller could come to no conclusion, because
he could obtain no proper medium for examining these
structures under the microscope. According to him, the
globules of the blood of the frog, are five or six times
larger than the primitive muscular fibres of that animal.
We estimate the diameter of the fibres of the facial nerve
in the calf, at from -000437 to -001023 English inch. The
finest fibres, he found by measurement, to be much less
than this, and not half as large as the globules of the blood.
The fibres of the spinal nerve in the cat when compared
with the globules of the blood, amount to about one-third
or one-half of their diameter. The nervous fibres of the
frog are about one-third or one-half of the human fibres,
and one-eighth of the blood globules of the frog.

The most important materials for nourishment appear to
be the albumen and fibrin dissolved in the blood, which

1835.] Lymph, Blood, and Chyle. 17

alone can penetrate the coats of the capillaries ; for the
globules must pass by the medium of the capillary vessels
from the arteries directly into the veins, as may be observed
by the microscope, while the texture absorbs the albumen
and fibrin, and again yields them up to the lymph vessels.
But it is not easy to determine the function of the globules,
or to say why they are bright red in the capillaries of the
lungs, and dark red in the same vessels of all other organs,
or why they pass through such an extensive circuit. That
they serve the purpose of nutrition, Muller considers very
improbable. Dutrochet conceives that they produce elec-
trical currents.

In the human body we find the fibrin and globules
separated; for the dissolved fibrin is separated from the
inner surface of the uterus. The coagulation of the men-
strual fluid appears to be obstructed by the presence of
some agent acting upon the fibrin, for the same reason
that many re-agents prevent the coagulation in the blood.
In urine, the menstrual fluid collects into masses, which,
under the microscope, appear to consist of globules of the
blood unchanged. Some secretions contain globules which
are not flat but round. The globules in the bile of the
frog are not elliptical like the nuclei of their globules,
but round and of a smaller size. The globules of human
saliva are much larger than the globules of human blood.
The milk globules, according to E. H. Weber, are one-half
or one-third smaller than the blood globules.

The healthy blood of man and the inferior animals, con-
tains no acid. The serum of man and the mammalia is
alkaline, that of the frog seems neutral, or at least its
action upon vegetable colours is very trifling. Hermann
states that he has found acid in cholera blood. The chief
difference between cholera and healthy blood appears to be,
that the former has a strong tendency to coagulate during
life, and that this inclination to assume a solid form, is an
important obstacle in the cure, whether we consider it as
the cause of the symptoms or the consequence of the disease.
Now, the carbonates of soda and potash, but more especially
caustic potash or soda, prevent the coagulation of the blood.
Prevost and Dumas affirm, that the blood of animals is
rendered uncoagulable by the addition of -—^^ of caustic

VOL. II. c

18 Dr, John Mulleins Examination of [July

soda. Hence, the propriety of administering large and
frequent doses of the carbonates to patients labouring under
cholera, as these can be taken internally without producing
the caustic effects of the pure alkalies.

BUFFY COAT.

In inflammation, the blood, when solidifying, presents a
different appearance from healthy blood ; for before it has
coagulated the red globules of the blood sink under the sur-
face of the fluid, so that the liquid portion appears scarcely
red, and often colourless or white, previous to coagulation.
Then it forms into a gelatinous mass, which is slightly red,
often white, or greyish yellow. The yellowish upper portion
of the cake has a smaller diameter than the under portion,
although at first the cake possessed a diameter equal to the
vessel. The cause appears to be that in inflamed blood the
red globules sink before coagulation, while in healthy
blood they do not descend till that period, and have the
fibrin diffused through the whole mass of blood ; but the
under portion of the coagulum contains the red globules ;
the upper part is destitute of them, and is termed crusta in-
flammatoria, or buffy coat.

Even before coagulation, one can tell whether there will
be a buffy coat or not; when the upper portion of the
liquid becomes first transparent and then whitish.

Babbington has observed, {Med. Chirurg. Trans, xvi. ii.)
that this colourless serum, before the coagulation, can be
skimmed off with a spoon, and that this serum coagulates.
Miiller has noticed this in the blood of a pregnant woman.
The serum of inflamed blood is not lighter than that of
healthy blood; and Miiller has noticed that when the
serum of strained blood, is mixed with a solution of common
salt, specifically lighter than the serum, the globules do
not sink further under the surface. Hewson's idea of the
cause of the buffy coat was, that as the inflammatory blood
is longer of coagulating than healthy blood, so the red
globules of the former have ample time to sink beneath the
surface before coagulation takes place. In experimenting
with the view of determining the propriety of this notion,
Miiller noticed in the blood of cats and men, the globules
sink in a quarter of an hour, one line ; and he remarked,

1835.] Lymph, Blood, and Chyle. 19

with great astonishment, that the blood globules in inflamed
blood sink as slowly under the surface as in healthy blood.
This led him to the fact that the globules sink much slower
when the fibrin remains dissolved in the blood, than when
blood is strained and the fibrin separated. He placed some
blood in three separate vessels. To one of these he added
a drop of a solution of carbonate of potash, in another fresh
blood, and in the third strained blood. The result of his
trials was, that inflamed and healthy blood, and that of preg-
nant women, exhibit the interesting appearance of globules
sinking very rapidly under the surface ; and, in all cases, it
was found that the globules in healthy blood in five or six
minutes sunk 1 or 1 J lines, and within an hour 4 or 5 lines.
The supernatant liquid was always whitish, and when too
much carbonate of potash was not added it coagulated into
a soft fibrin, which in one case was covered by a kind of
crust. Scudamore has shewn that inflamed blood contains
more fibrin than healthy blood. Blood containing fibrin
in solution possesses a higher specific gravity than blood
freed from fibrin, and it is obvious that globules which are
specifically heavier than the liquid portion, must remain
suspended in it if they adhere to it until this adhesion
ceases, when they will fall down. The adhesion of the
globules is much greater to serum which is freed by straining
from fibrin, than to serum which contains fibrin in solution,
and whose coagulation is impeded. This might easily be
accounted for, because the globules have a great attraction
for water, which dissolves them in every proportion.

Serum, which contains albumen in solution, has more
attraction for the globules than blood which possesses both
albumen and fibrin. We can produce a rapid descent of
the globules in the strained blood of men and cats, by
mixing it with a concentrated solution of gum-arabic ; not
so, however, in that of sheep and oxen. When coagulation
takes place slowly, the portions of fibrin and albumen must
have a greater attraction for each other than for the glo-
bules ; and when the globules are heavier than the solution
of albumen and fibrin, the attracted portions of the speci-
fically lighter solution will collect above and the globules
below. The consequence, therefore, is, that slow coagu-
lating inflamed blood contains more globules and less liquid

c2

,20 Dr. John Mullers Examination of [July

blood below, while above, the liquid portion predominates,
and there are few globules, the fibrin of the whole mass,
however, coagulating above.

This explanation of the huffy coat is satisfactory, if it be
allowed that inflamed blood always coagulates more slowly
than healthy blood. Dr. Davy has observed that it does
not always coagulate slowly.

EFFECT OF GALVANISM ON THE BLOOD.

When a drop of serum is exposed to the galvanic action,
a deposit of albuminous globules takes place at the zinc
pole, in consequence of the accumulation of acid towards
that pole, and not, as Dutrochet thinks, because the albu-
men is electro-negative. The globules of the blood do not
accumulate at either pole, but at both poles they undergo
a decomposition at the expense of the colouring matter, for,
under the hydrogen bubbles disengaged from the copper
pole, we can observe a filamentous substance of a clear
brown colour. These are particularly observable in the
blood of the frog, but not in that of a mammiferous animal
which has been killed.

Miiller submitted a solution of the colouring matter to
the galvanic action. A red coagulum was found at the
zinc pole, in the shape of a magma, composed of albumen and
the red matter of the blood. This deposit increased in quan-
tity, but diminished in intensity of colour. At the copper
pole, gas and flakes were formed, which Miiller attributes to
the solution of the animal matter in the alkaline solution.

Miiller found that the fibrin goes to the zinc pole, and
may be considered electro-negative ; but fibrin also enjoys
the property of re-acting upon acids, and can act either as
a base or acid. When fresh fibrin dissolved in serum
separated from the blood globules, is exposed to the action
of galvanism, the albumen of the serum is deposited at the
zinc pole, but the coagulation of the fibrin takes place in
the form of drops, as if it had not undergone the galvanic
action.

ON THE CHYLE.

The chyle contains globules, with albumen and fibrin in
solution and fat. In coagulating, the fibrin encloses a
portion of the globules, while the remainder exists in sns-

1835.] Lymph, Blood, and Chyle. 21

pension in the serum, and renders it muddy. The albumen
of fresh chyle, like that of the serum of the blood, coagu-
lates when a great quantity of caustic potash is added.

Muller found the globules of the chyle in the cat, dog,
&c., spherical, and not flattened. He observed also that
they are sometimes smaller than those of the blood, as in
the dog ; while, in the cat they are equal in size to those
of the blood, and larger, as in the rabbit. He differs from
Tiedemann and Gmelin, who consider the white colour of
the chyle to be derived from the particles of fat swimming
in it, and who say that it becomes transparent when ether
quite free from alcohol is added to it. Miiller tried the
experiment upon the chyle of the cat, but obtained a diffe-
rent result ; for he observed the globules, which had not
changed their colour.

Article IV.

On Accidental and Complementary Colours. By Charles
ToMLiNSON, Esq.

1. In a letter that I had the pleasure of addressing to the
Editor of this Journal, (vol. i. p. 440), I pointed out a ready
method of observing the accidental colours of certain
chemical solutions by means of mercury, and stated a few
results when reddish-purple, red, yellow, and blue solutions
were employed.

2. I should have stated that the best mode of observing
these colours is when the finger is placed horizontally, a
plane passing through which, and communicating with the
opposite part of the periphery of the glass, forms an angle
of about 45°, while the eye should form about an equal
angle on the other side.

3. It will naturally be inferred that every coloured solu-
tion yields the same accidental or complementary colour,
when observed by means of the reflecting surface of mercury,
and such, indeed, is the result, provided the solution be
sufficiently transparent to allow of two reflections of the
periphery of the glass.

4. I had some difficulty in obtaining a good orange solu-
tion, but after repeated trials I succeeded in obtaining an
excellent colour, by adding a solution of oxalate of ammonia
to a solution of bichromate of potassa. On placing this

22 Mr, Tomlinson on [July

solution on the mercury the accidental blue was obtained
very perfectly. The surface of the mercury, however, soon
tarnishes.

5. I have employed several green solutions, and find that
one to succeed which is obtained by the addition of alcohol
in sulphuric acid to a solution of bichromate of potassa.
This compound, (an impure sulphate of chromium) is of a
dark and decided green, and yields a red accidental colour.
With a lighted taper, other lights being extinguished, a
beautiful complementary reflection is obtained, and the
surface of the liquid is interspersed with red rays.

6. The true accidental colour of green is violet-red, so
that the last experiment did not satisfy me. To produce
this accidental colour, a grass-green solution must be
employed, which, I find, may be formed by the addition
of the bright blue solution of nitrate of copper (7.) to the
red solution of bichromate of potassa. A fine complemen-
tary colour is obtained from the solution on mercury, but
an amalgam is soon formed on the surface of the metal,
which prevents further observation. If it be required to
repeat the experiment the amalgam can be easily moved
aside with a flat piece of glass.'*

7. For a blue, I employed nitrate of copper, the filtered
residual solution from the retort, after making binoxide of
nitrogen. This bright blue solution on mercury yielded a
fine orange red.

The nitrate of copper of commerce I have often found to
consist of a confused mass of green crystals. Practically,
I find, that the bright blue solution, when quickly evapo-
rated, yields a confused green crystallization ; but by careful
evaporation, bright blue crystals, the colour of the solution,
are obtained. The green salt probably contains less water
than the blue, and certainly does not deliquesce so soon ;
it is of the colour of the subsalt, but distinguished from that
by being soluble in water. The solution of the latter is of
a greenish-blue, yielding a reddish accident on mercury.

8. I obtained a violet solution by means of archil f lichen
roccellaj, and the accident, a delicate yellowish green, was
immediately obtained. A few drops of liquor ammonige

• I shall have occasion to refer to this amalgam in my next paper on Visible
Vibration, respecting its appearances during and imioediately after the vibration
•f the glass.

1835.] Accidental and Complementary Colours.

'23

should be added to the solution previous to the observation,
as the archil of commerce sometimes contains an extraneous
acid, which imparts a reddish tinge to the dye.

9. Water slightly impregnated with carbonate of lime,
on mercury, yielded a very faint accidental black.

10. Very dilute black gallate of iron yielded a faint acci-
dental reflection of white.

11. The result of these experiments may be thus
arranged : —

Solutions on Mercury.

Colours.

Ocular Spectra.

slightly red- )

by)

1. Litmus

dened

2. Litmus, reddened

nitric acid . . , . S

3. Oxalate of ammonia & ^

bichromate of potassa

4. Chromate of potassa.

Muriate of lime, with
excess of acid .

5. Indigo in sul. acid .

6. Nitrate of copper .

7. Sulphate of chromium

8. Nitrate of Chromium .

9. Archil

10. Dilute black gallate i
of iron >

11. Dilute carbonate of i
lime 5

}

Reddish-purple

Red

Orange

Yellow

Indigo

Blue
Dark-green
Grass-green

Violet

Black
White

Light-green.

Dark-Green.

Blue.

Indigo.

Orange-yellow.
Orange-red.

Red.

Violet-red.

Yellowish-green

Whitish.

Blackish.

12. Although these results (with the exception perhaps
of 10 and 11), were sufficiently satisfactory; yet, being
anxious to introduce into my lectures an easy method of
exhibiting these colours, so as to be at once seen and appre-
ciated by my pupils, I endeavoured to supersede several
objections that were attached to the above mode, and the
principal objection was, perhaps, found in the fact, that the
mercurial surface soon became tarnished, and the employ-
ment of so large quantities of mercury in several glasses,
so as to shew all the results at one time, was, at least, in-
convenient. I, therefore, proceeded to inquire, whether
similar results could not be obtained by means of disks of
stained glass.

13. Of these I procured at first four, each three inches
in diameter, a red, a yellow, a blue, and a green. On

24 Mr. Tomlmson on [July

placing them severally on the reflecting surface of the
mercury, and proceeding in the same manner as with the
solutions, I obtained complete and distinct accidental or
rather complementary colours. But one great difficulty
still remained, the emj^loyment of inconvenient bulks of
mercury.

14. To obviate this objection I had recourse to a plane
mirror which I formed at first out of a piece of common
window glass, * the size of the stained disks, and obtained
the desired results by placing the disks successively thereon.

r5. In furtherance of this idea I have constructed a little
apparatus for the purpose of observing the accidental
colours. It consists of a plane circular mirror, three
inches in diameter, on which a coloured disk of the same
size is placed, and the two glasses are thus enclosed in a
circular frame of wood. On holding the instrument
obliquely inclining to the light,t and bringing the periphery
close to the eye, and looking downwards into the glasses,
all reflected objects are doubled, such as the window frame,
chimneys, the distant cathedral spire, &:c. The window
frame being marked with broad bands of complementary
colours, while the second reflection of the spire, &:c., is the
complementary one. It will be evident that the frame
may be constructed in the form of a box, the inner side of
the cover containing simply a plane mirror, and the box
from three to seven or nine disks of stained glass. If three
only are employed, they of course will be red, yellow, and
blue; if seven, they will be the primitives. In employing
the instrument it will only be necessary to place one of the
disks on the plane mirror within the cover, and after the
observation as directed above, the stained disk may be re-
moved and another substituted.

16. It must not be forgotten that the stained glass must
either be very thin, or the stain sufficiently light to allow

* It is of course known that a plane mirror may be speedily formed by the re-
duction of mercury from the fulminate, the powder being equally and evenly
spread over the surface of the glass, and then ignited. A less expeditious, but an
infinitely better mode, is that recommended by Faraday, Chemical Manipulation,
page 574.

t I should have observed before, that the experiments in this and the preceding
paper must be performed near the window, except, of course, where flame is em-
ployed ; but the instrument mav be employed in all cases where direct natural
light is present.

1835.] Accidental and Complementary Colours. 25

the plane mirror to perform its part. If dark greens or
blues be employed the experiment will not succeed, but
with darkish reds and yellows no obstruction is offered.

17. For a complete instrument* the following glasses
may be chosen : —

1. Red.

2. Orange.

3. Yellow.

4. Light green.

5. Light blue.

6. Light indigo.

7. Light violet.

8. Light milky- white.

9. A faint shade of black.

The two latter may, however, be omitted, as the results
obtained by their means are not altogether satisfactory.

18. The form of the instrument may, however, be much
varied. An oblong plane mirror with several smaller
oblong pieces of stained glass, the lengths of which must be
placed at right angles to the length of the plane mirror.
Thus, as many accidental colours will be observed as there
are primitives.

19. I find that the coloured solutions (11) placed on a
plane mirror will afford all the results contained in my first
and those in the former part of this paper. A box may
be formed with a plane mirror at the bottom, well luted
round the edge to prevent the solutions from spoiling the
silvering ; but the best mode of exhibition is to fix the
mirror at the bottom of a cylindrical glass with a perfectly
flat surface, the mirror being placed on the outride, or the
outside bottom itself may easily be silvered.

20. In offering these experiments to the notice of your
readers, I may be allowed to state that they are altogether
opposed to the existing theory of accidental colours. At
the same time, I do not feel myself suflftciently prepared to
offer another theory that may chance to be received as
satisfactory.*!*

21 . Not having the advantage of reference to a scientific

* An ingenious friend has suggested the term " Perichromascope," or " Pros-
chromascope," as applicable to this little instrument.

t I am aware that M. Plateau has a new theory of accidental colours, but I
have not been so fortunate as to see it.

26 Mr. Tomlinson on [July

library, except my own, which is necessarily very limited,
I could not examine one or two eminent and recent treatises
on optics ; I have, however, carefully examined seven or
eight works on chromatics, and have found nothing at all
bearing on the nature of these experiments, except in Sir
David Brewster's Treatise on Optics, to whom I feel it due to
state that the adoption of stained glass by me was suggested
by the following passage in his work, p. 309. ** Accidental
colours may also be seen by looking at the image of a candle,
or any white object seen by reflection from a plate, or sur-
face of coloured glass, sufficiently thin to throw back its
colour from the second surface. In this case the reflected
image will always have the complementary colour of the
glass. The same effect may be seen in looking at the edge
of a candle reflected from the water in a blue finger-glass ;
the image of the candle is yellowish, but the effect is not so
decided in this case, as the retina is not sufficiently impressed
with the blue light of the glass."

22. I should be sorry to be supposed to question the
statement of so distinguished a philosopher and optician as
Sir David Brewster, but I may be allowed to state that with
coloured glass alone I am seldom successful in obtaining a
sight of the complementary colours of the glasses, possibly
because my disks are not sufficiently thin : Whereas, with
the plane mirror reflector behind the disks, the complemen-
tary colours are immediately observed in all their well
defined beauty.

23. With regard to the reflected image of a candle in
water contained in a blue glass, the experiment is, for the
reason stated in the quotation, imperfect. I have found it
to succeed tolerably well with a strong homogeneous white
light. It succeeds also with the light obtained from the
mixed gases on lime, but this light is not homogeneous. I
have decomposed it by a prism, and have obtained the
prismatic spectrum from its rays.

Note,— In the foregoing paper I have omitted to state,
that the sulphate of chrome affords a remarkable and
beautiful illustration of complementary colour, its solution
being intensely green by reflected, and of a brilliant ruby
by transmitted light, and yet this solution yields purple
crystals ! Still, I find that there are circumstances under

1835.] Accidental and Complementary Colours. 27

which the solution is green by transmission as well as by
reflection, as may be seen if a test tube be filled with the
solution ; or, if a test glass, the shape of an inverted cone,
be employed, the light transmitted at and about an inch
above the apex will be green, and the ruby will gradually
appear as the eye is moved upwards towards the base, if I
may so speak. The transmitted light is also green, when
the solution is contained between two watch glasses placed
so as to form two convex surfaces.

These observations apply also to the green solution
obtained by mingling muriatic acid and alcohol with a
boiling solution of chromate of potassa, in preparing the
hydrated oxide of chrome, and in either case the light may
be natural or artificial; indeed, the experiment is more
striking when flame is employed.

The nitrate of chromium I find to be green by reflection
and transmission.

Brown Street^ Salisbury^ Sth June, 1835.

Article V.

On the Number and Character of the Colours that enter into
the Composition of White Light. By P. C.

Notwithstanding the present boasted state of Science,
and the numerous discoveries and improvements which
have undoubtedly been made, the whole of our arrange-
ments, with one solitary and splendid exception, the theory
of universal gravitation, are in a state of the greatest un-
certainty. There is scarcely a branch of science that does
not present us with at least two theories, the rival preten-
sions of which, though founded on different and even
opposite principles, it would be extremely difficult to decide.
The theory of chemistry, perhaps, thanks to the immortal
Lavoisier, for setting us free from the trammels of phlogiston,
is less chargeable with this defect than most others ; but
while one of its most important agents is treated in connexion
with another branch of science, by one party as the effect
of mere motion, and by another as a substantial body, and
chemistry leaves a question in which it is so deeply in-
terested , undecided ; it cannot be considered wholly divested
of uncertainty. It must be confessed, however, that the

28 P. C. on the Colours that enter into the [July

fault is chargeable rather upon its non-interference than its
want of power to decide.*

It is not perhaps surprising that questions which require
for their determination the concurring evidence of various
classes of phenomenja, which at present form the basis of
distinct sciences, and a connexion between which is not
usually considered essential, should remain without satis-
factory answers ; but there are questions of minor import-
ance, the unsettled state of which has no such excuse to
offer; their solution requires only the arrangement and
combination of known and admitted facts ; and we can only
account for the state of uncertainty in which they have
been suffered to remain, upon the well known principle,
that whatever is constantly within our reach is frequently
neglected, while distant objects, which present greater dif-
ficulties without, perhaps, corresponding importance, are
pursued with avidity.

Among questions of this description, the number and
character of the primitive coloured rays which enter into
the composition of white light, is one, the decision of which
is of considerable importance to the arts ; and we have,
therefore, the inducement of utility, in addition to more
speculative motives for its investigation.

Sir Isaac Newton, the illustrious founder of the material
theory of light, divided the spectrum into seven colours ;
each of which he considered differed from the others in its
degree of refrangibility, but by such an imperceptible grada-
tion, that the most refrangible ray of one colour, approached

* It has long been evident that the material character of light and heat must
stand or fall together : if there had been a doubt on this point, the recent dis-
coveries of Professor Forbes must have removed it. How then will the chemist,
the results of whose experiments have hitherto been satisfactorily accounted for,
by considering caloric a material and indestructible agent, reconcile the change
which must be the necessary consequence of adopting the undulatory theory of
light, so as to preserve the consistency of his explanations 1 Or rather, will he
not impose this impossible task upon the undulationist, as one of the conditions
upon which his theory ought to be received.

The philosopher who does not confine his views to one branch of science, but
who looks upon the different phenomena of nature as a whole, which must ulti-
mately be connected in theory, as they are already united in operation, will
certainly not tolerate the retrogression which must be the necessary consequence
of adopting such opposite opinions respecting the same object when applied to
diflferent purposes. If heat be a material agent in chemistry, it must be a
matrial agent in those experiments which connect it with light.

1 835 .] Composition of White Light. 29

in every respect within the nearest limits, to the least re-
frangible ray of the colour adjoining ; and, consequently,
that there was no distinct line of separation between dif-
ferent colours.

If this opinion be well founded it is of little consequence
into what number of colours the spectrum is divided ; it
being, in fact, if this principle be admitted, formed of innu-
merable circles of colours, each differing from the other,
though imperceptibly, in colour as well as in refrangibility.

But there does not appear to me to be any good ground
for such a conclusion : it is directly in opposition to the
well known experiment of Newton, in which, by making a
hole in the screen upon which the spectrum was received,
he suffered any one of the colours to pass and fall upon a
second prism, which now formed a correct image of the
hole by which it was admitted, and not an elongated
image, which it would have done if light of the same colour
differed in refrangibility ; and, at a future time, I shall
produce other experiments which, in my opinion, will not
leave a doubt on the subject.

Newton's erroneous views arose, I apprehend, from his
making his experiments with light admitted through small
apertures, by which it was inflected into an innumerable
variety of different directions ; and as a subsequent refrac-
tion, upon well known optical principles, bends the rays so
that a difference in their previous direction is retained in
their further progress, every colour after being refracted
by the prism, instead of being formed of parallel rays, must
have had an almost infinite number of different directions.

Diffracted light may be formed either by admitting it
through a small aperture, or through a lens of very short
focus ; and the light thus admitted appears to have similar
properties. Now, we know that in the latter case, the rays
are so refracted, that at a certain distance from the lens they
meet in one point, and, consequently, that every circle of
rays proceeding from the lens, at different distances from
the centre, must be refracted so as to form different angles
with the central ray. The light, then, thus prepared, must
meet the face of the prism at different angles of incidence ;
some of the rays at a larger and some at a smaller angle than
the central ray; and the previous difference of direction,
must thus be considerably increased by the second refraction.

30 P. C, on the Colours that enter into the [July

It is not surprising, therefore, that light admitted to the
prism through a small aperture should, after refraction,
have some of its rays of different colours inseparably
blended. The difference of refrangibility is in this case
compensated by a different degree of refraction, and the
rays being thus brought to a state of parallelism, no dis-
tance, however great, can effect their separation.

But the most convincing proof is, that if we suffer the
direct and unobstructed rays of the sun to fall on a prism,
a spectrum is formed in which the colours, with the excep-
tion of the violet, do not greatly exceed the breadth of the
face of the prism ; each colour being, in fact, when fully
developed, a distinct image of it ; or of the breadth of light
which falls on its surface. There is neither in this case the
extraordinary elongation, which in some of Newton's ex-
periments, were in the proportion of seventy to one, nor
the variety, nor the regular gradation of colours, which
were produced in these experiments.

If we observe with attention the developement of the
spectrum, thus produced, in different stages of its progress,
we shall be enabled to form some idea of the number and
character of the primitive colours which it exhibits ; and
we shall then be prepared to confirm or correct these
theoretical views, by submitting them to the test of ex-
periment.

If we receive the spectrum on a screen placed at a few
inches from the prism, we shall observe a breadth of white
light in the centre of the spectrum, fringed with violet and
blue on one side, and yellow and red on the other ; as the
screen is withdrawn to a greater distance from the prism,
the fringes increase in breadth at the expense of the white
light, which at length wholly disappears ; and the spectrum
then appears to be formed of four colours, red, yellow,
blue, and violet ; by withdrawing the screen still further,
green makes its appearance between the yellow and the
blue; and, finally, the two latter colours entirely disap-
pear, apparently absorbed in the green ; the colours being
now reduced to three, red, green, and violet.

In this experiment the white light is evidently formed by
the intersection of all the different colours, which, although
they have received different directions by refraction, are still
superposed in the centre, in consequence of the succession

1836.] Composition of White Light. 3t

of rays supplied by the breadth of light which falls on the
face of the prism. The fringes are formed of light which
wants some' one or more of the colours necessary to consti-
tute white light. Now, whatever number of colours may
be included in the spectrum, only two of those which make
their appearance on the fringes, can be simple colours ; the
one which, by the refraction of the prism, is lifted above
the rest in consequence of its superior refrangibility ; and
the one which is left below all the others in consequence of
its inferior refrangibility ; the former of these is the violet,
and the latter the red. The blue under the violet, and the
yellow above the red, both adjoining the central white,
must necessarily be compound colours; for, the violet
which appears at the upper edge extends to the central
white, and therefore, must be superposed so as to form a
constituent part of the blue which lies between them, and
the red which appears at the lower edge must, for the same
reasons, enter into the composition of the yellow.

Blue and yellow, then, being thus discovered to be com-
pound colours, and it being also discovered that violet enters
into the composition of the former, and red into the compo-
sition of the latter ; the appearance of the spectrum when,
upon its further developement, the green makes its appear-
ance, is easily accounted for ; the violet and red, the two
extreme colours of the spectrum, being in this stage of
its progress quite separated, leave the green (which was
before superposed by both these colours in the central white)
a distinct colour ; and as the violet and red, by continuing
to increase the distance of the screen, recede from each
other, the green becomes more and more developed, until
it acquires its full breadth, when the blue and yellow, in
both of which it must have been a constituent principle,
disappear.

Red, green, and violet, then, are evidently the only primi-
tive colours. Red and green form yellow; in larger propor-
tions of the former orange ; violet, and green form blue ;
in larger proportions of the former, dark-blue and indigo :
Red and violet form crimson ; in larger proportions of the
former, pink; and in larger proportions of the latter,
purple.

No shade of colour can be formed of more than two
colours ; for, the moment the third is added, its comple-

32 P. C. on the Colours that enter into the [JulV

mentary colours form white light with it, and they disap-
pear, leaving the colour or colours which happen to be in
excess, diluted with the white light thus formed. A red-
blue, a violet-yellow, or a green crimson is, therefore,
impossible. It is upon this principle that when blue and
yellow are superposed, green makes its appearance, there
being a surface of this colour combined with violet to form
the blue, and another surface combined with red to form
the yellow, a mixture of the two colours must necessarily
leave a surface of green in excess.

These views lead to considerations of importance to
several of the arts ; but having already extended this paper
beyond the limits I had prescribed to myself, I shall reserve
this part of the subject for another opportunity.

The theoretical views derived from the appearance of the
spectrum in different stages of its developement, may be
illustrated by taking three cards, the size of the face of the
prism, of the three colours, violet, green and red ; and,
after placing them with their edges parallel, which will
represent the superposition of all the colours to form the
white light incident upon its surface, gradually raise the
violet and the green cards, the former twice as much as the
latter, which will produce a separation of the colours nearly
in the proportion they are separated, by gradually increased
distance after refraction ; the parts of the cards which
remain superposed will exhibit the different combinations
as they appear on the screen at different distances from the
prism. Where the three cards are together, the part of the
spectrum they represent is white ; the green and red, from
which the violet is withdrawn, form yellow ; the green and
violet, from which the red is withdrawn, blue ; and the full
developement of the spectrum is shewn by the complete
separation of the three cards, (see figures 1 & 2).

I am not acquainted with any writer who has noticed the
appearance of the spectrum previous to its full develope-
ment except Ritter, who did not appear to comprehend its
character, but considered it, when received on a screen a
few inches from the prism as forming two spectra, which
at greater distances became united.*

If you consider the subject deserving a place in the
Records of Science, I intend, in a future communication, to

• I quote from memory, having no book with me to refer to.

1835.] into the Composition of White Light. 33

produce such experimental confirmation of the theoretical
views here advanced, as will, in my opinion, leave no doubt
on a question which, though it may not be considered of
any great importance, it is certainly desirable to settle.

.../

Q

va

r 1

iaa

.*

O

"^

^

1^

o

i

?

g;

•53

9
10

In Fig. 1. the light which falls on the face of the prism
a c, is represented emerging from J c in three different direc-
tions, so as to become completely developed upon a screen

VOL. II. D

34 On the Relation of the Specific [July

placed nearer to the prism than k Z, it assumes different
appearances at different distances ; at rf e, for instance, it
has a white centre, fringed at its upper edge with blue and
violet, and at its lower edge with yellow and red ; at f g
the white light disappears, and the spectrum is then formed
of four colours, red, yellow, blue, and violet. At A i it has
a green centre, which increases the number of colours to
five; and at k Z, when fully developed, it is reduced to
three, red, grean, and violet.

Fig. 2. represents a front view of the spectrum, when
the screen is placed atcZe; and it also represents the super-
position of the three cards with which the subject has been
before illustrated ; the red card extends in breadth from
r to r, the green card from g to g, and the violet card from
V to n. P. C.

Weston Super Mare,
May 2lst 1835.
To the Editor of the Records of General Science,

Article VI.

On the Relation of the Specific Heat of Bodies to their
Atomic Weights.

This paper is intended to convey a condensed view of the

researches of Avogrado, an Italian philosopher, as related

in two separate memoirs.*

It may be proper to observe that in a previous paper,t

from the consideration of the affinity between the density

and specific heat of bodies, he had established the formula

7n
rf = — 3 where the density of the ductile metals, is simply

proportional to the mass of the atom divided by the cube of
its affinity for heat, or affinitary number as it may be termed ;
a represents the quantity which corresponds with the cube
of the distance of the centres of the atoms, that is to say,
this distance is simply proportional to the affinity of each
substance for heat, the mass of the atom not entering into
its determination.

♦ Ann de Chiin. et de Physique, t. Iv. and Ivii.

t Memorie delln Reale Accaderaia delle Scieuze di Torino, xxx. 91,

1835.] Heat of Bodies to their Atomic Weights. 35

The affinitary number is obtained by dividing the atomic
weight of a body by that of potassium, which is considered
unity ; thus, the affinitary number of gold will be ^f.5=2'5,
or, as Avogrado makes it, 2a:a6— 5-073. Then m = 5*073,

£/=22-18and6Z=^ora=^ygivesa = ^f^^^ = '6115,

the affinity of gold for heat.

M. Avogrado, by his experiments on the specific heat of
bodies, has confirmed the accuracy of the law deduced by
Dulong and Petit, from their researches, that the specific
heat of the atom of a compound gas is expressed hy the square
root of the whole, or fractional number of the atoms of the
simple gases, hy whose combination the compound atom is formed.
He has, however, been more particular in his expression of
the law, which, according to him, is of the following import :
the specific heat of an atom of a compound body is equal to the
square root of the whole, or fractional number, expressing the
atoms or portions of atoms which, by their combination, form
the atom of the compound body, whether in the solid or liquid
state, adopting as unity the specific heat of some simple body
in the same state. This rule, however, is not easily applied
to solids and liquids, because the atoms and volumes of
gases are equivalent ; whereas, in the former classes, it is
a question requiring much investigation to resolve, what is
the composition of the compound atom in the solid or liquid
state. For the composition, according to theoretical con-
siderations, is often different from what it is in the gaseous
or vaporific state. Impressed with a desire of clearing up
this difficulty, Avogrado was led into the discussion of the
subject of the atomic weight of bodies, and has considered
it proper to reduce the numbers attached to them by the
Continental chemists to one-half. These new numbers being
deduced from the consideration of the specific heat, he has
termed them thermic atoms. The table of the specific heat
of bodies, which was the result of his researches, has been
already presented to the reader (Records of General Science,
vol. i. 108.) The numbers were ascertained by means of an
instrument of simple construction. The vessel in which
the substance to be experimented on was placed, consisted
of a cylinder of thin brass, with a flat, upper edge. To this
is applied a brass plate, pierced with three holes in its
circumference, to enable three screws to pass which rise

D 2

36 On the Relation of the Specific July

on the edge of the vessel, and are tightened from above by
nuts, so that by interposing between the plate and the edge
of the vessel a portion of oil skin, the access of water and
external air is completely prevented. This vessel is con-
tained in a larger one, also made of brass, intended to hold
a determinate quantity of water at the temperature of the
atmosphere, in which is placed a small mercurial thermo-
meter with a brass scale, and covered bulb, which is com-
pletely immersed in water.

To ascertain the specific heat, the small vessel was filled
with the substance in powder, if it was a solid, and the
weight noted. The vessel was then closed with the brass
plate, and was kept in a vessel full of boiling water, until
it was concluded that it, as well as its contents, had acquired
all the heat which could be communi<iated to it by boiling
water.

The temperature of the air; that of the water contained
in the interior vessel of the apparatus, and that indicated by
the thermometer which was plunged into it were marked ;
the small vessel was then rapidly removed t from the vessel
of boiling water, by means of a pair of pincers, and placed
in the exterior vessel. This being done, the temperature
indicated by the thermometer of this vessel was marked
every minute. This temperature increased at first rapidly,
then slowly, and generally reached its maximum in eight
or ten minutes. It is obvious that this method would be a
very easy one for determining the specific heat of bodies,
if it did not happen that during the experiment, the water
in the exterior vessel is constantly giving off* heat at the
expense of the substance, which is the object of experiment,
and conveying it to the vessel and surrounding bodies.
Avogrado, however, corrected this source of error by
applying Newton's law, according to which, the communi-
cation of heat is continually proportional to the actual
difference of temperature between the two bodies, a law
which is exact for moderate temperatures. He found also
a formula nearly accurate, in which the excess of tempera-
ture of the exterior vessel, and of the water contained in it,
above that of the surrounding air, as well as of the interior
vessel, and the substance contained in it above that of the
water, is regarded as being a mean during the experiment
between the initial and final excess.

1835.] Heat of Bodies to their Atomic Weights, 37

According to the law of Dulong and Petit, the specific
heat of simple bodies, taking for unity that of an equal
weight of water, multiplied by their atomic weights, gives
us the constant number -375, (or -376*) In other words,
the specific heat of an atom of these bodies is '375, adopting
as unity the specific heat of a body of water, equal in weight
to that of an atom of oxygen. From which it follows that
if the same law applies to oxygen, and if the relation
adopted between the atoms of different bodies and that of
oxygen, is really that which exists between the atoms, to
which the law refers, and which maybe called their thermic
atoms, the specific heat of oxygen in the solid state, ought to
be 0*375, taking as unity that of an equal weight of water.
This, however, cannot be verified by experiment, because we
are unacquainted with any method of operating upon oxygen
in the solid state. It is obvious, therefore, that to fix the
atoms of bodies relative to oxygen, is somewhat arbitrary ;
for the rule of the equality of the specific heat of atoms,
would be verified by doubling or trebling all the atoms in
relation to that of oxygen, or in taking a half or third, pro-
vided that we changed at the same time the constant number.

Let us turn our attention to various bodies with this object
in view. 1. The specific heat of carbon appears to indicate
that we may reduce the atoms of sulphur, and the metals, to
one-half of the numbers attributed to them at present. The
atom of carbon is really 0-764 (or rather -75, as will be pre-
sently seen) of the atom of oxygen. The same relation ought
then to subsist between the atoms of carbon and oxygen,
both in the solid state, in order that the law of Dulong and
Petit may be applicable. The specific heat of carbon,
according to the determination of Crawford and Avogrado,
is -25, or one fourth of that of water. Now, '75, the true
atom of carbon (and not -764, the number adopted on the
Continent) + '25 = -1875, or the half of -376, and exactly
the half of -375, the co-efficient adopted by Avogrado.
From this fact Avogrado argues that the co-efficient of the
law of Dulong and Petit ought to be reduced to this half
number, -1875, and for the same reason that the atoms of

* Thomson on Heat and Electricity, 97..

38 On the Relation of the Specific [July

sulphur and the metals should be reduced to the half of
the numbers which represent them at present. The specific
heat of carbon would then be, according to this modified
law S-^'^ = ^*2^' ^^ exactly the result of experiment.
The number deduced by Avagrado is, however, incorrect,
because he adopts -764 as the atomic weight of carbon,
instead of '75, the number obtained by Dr. Thomson, and
which is here substituted.

In this view of the subject the specific heat of oxygen, in
the solid state, ought to be '1875, a number which Avo-
grado also finds to be nearly the specific heat of oxygen in
the state of gas,^by a calculation founded on the experi-
ments of Berard and Delaroche, relating to the specific
heat of the oxygen of the air compared to that of water ;
and it is probable that the specific heat of a body, which pre-
serves the same atomic composition may not differ much in
each state. This could not happen, however, if the numbers
are preserved to which Dulong and Petit applied their law,
because the specific heat of oxygen would then be '375, or
the double of that which it possesses in the gaseous state.

2. Phosphorus. — The specific heat of this substance was
determined by Avogrado, by observing how many degrees,
phorphorus at several degrees below zero cooled the liquid
(which was spirit of wine) in the exterior vessel. The mean
of two experiments gave for the specific heat of phosphorus
0*385, taking that of water as unity. Now, the atomic
weight of phosphorus being 2* we obtain an approximation
to thjs number if we take the fourth of it, or '5, and divide
the co-efficient -1875 by it. The quotient is -375, or the
specific heat of phosphorus in the solid state. Hence,
according to the view laid down by Avogrado, the thermic
atom of phosphorus will be '5. In the gaseous atom he
considers that there would be 8 thermic atoms

3. Arsenic. — The atom of this substance is 4*75, the half
of which is 2-375. To obtain the specific heat we have
•i-^TTb =* 79 or '80. The number obtained by the experi-
ment was -81. Mitscherlich has found the density of the
vapour of arsenic correspond to double the number at
present received as the atom of arsenic. There would,
therefore, be in the gaseous atom four thermic atoms.

1835.] Heat of Bodies to their Atomic Weights. 39

4. Iodine. — For the specific heat of this substance in the
solid state, Avogrado obtained the number -089.

Now, to procure an approximation to this number tJieore-
tically, we must divide the atom 15*75 by '8, and we have
1-967. Now, ^1^ = -095. Hence arsenic is analogous to
phosphorus.

We may, perhaps, extend the same analogies to bromine,
and chlorine. Avogrado infers that the combining atom of
azote is formed of 2 thermic atoms; those of chlorine,
iodine, bromine and phosphorus, of 8 thermic atoms, and
that of arsenic of 4 true or thermic atoms, each multiple
atom requiring 5 atoms of oxygen to form nitric, chloric,
iodic, bromic, phosphoric, and arsenic acids.

Now, with regard to compound bodies, Avogrado consi-
ders that the law deduced from the experiments of Dulong
for the specific heat of compound gases applies equally to
the specific heat of compound bodies in the solid state, viz.
that the specific heat of the compound atom of a solid body,
taking as unity that of a simple atom, given by the law of
Dulong and Petit, is represented by the square root of the
whole or fractional number, which expresses the atoms or
portions of simple atoms of different kinds, entering into
the formation of this compound, a number, which, for brevi-
ty's sake, may be termed the constituent number of the com-
pound atom. Consequently, to obtain the constant number,
•1875, it is necessary to multiply the specific heat of com-
pound bodies (taking that of an equal weight of water as
unity) first by the weight of the compound atom, taking
that of oxygen as unity, as for simple bodies, and to divide
by the square root of the constituent number ; and recipro-
cally to obtain the specific heat of a solid body, taking as
unity that of an equal weight of water, we must multiply
the square root of the constituent number by '1875, and
divide by the weight of the compound atom. It will now
be proper to consider the application of this law to the
difi'erent kinds of compound bodies.

1 . Water. — If we suppose that the atom of water in the
solid, liquid and vaporific state is the same, and represent-
ing its composition to be 1 atom hydrogen .-}- J atom
oxygen, its constituent number will be 1*5 of which the
square root is 1*225. Now, let us multiply the square root

40 On the Relation of the Specific [July

of the constituent number, according to the law as above
stated by theconstant number, and then divide by the weight
ofthe compound atom; then 1-225 x -1875— '0525 =0-40846.
= the specific heat of water in the solid state or ice/ The
specific heat of ice, according to Clement and Desormes, is
•72, according to Avogrado, -92. We arrive at a mean of
these numbers, by supposing that the atom of the vapour of
water is divided into four parts in passing to the solid state ;
for then the constituent number will be four times less, and
its square root the half of the preceding, while the com-
pound atom which enters as the divisor into the expression of
the specific heat, will become four times less. Hence the cal-
culated specific heat will be 0*8168 or a mean of the two
experiments mentioned ; for -92 + 72 -r 2 = -82. If how-
ever we calculate the specific heat, according to the view
taken of the composition of water in this country, we have
then, 2 as the constituent number, by dividing the square
root of which by -5625 half the atom of water, we obtain
•94 for the specific heat, a close approximation to the de-
termination of Crawford and Avogrado. If in place of * 1 875,
we had adopted the number of Dulong and Petit, viz., -375;
the calculated specific heat of ice would have been -8168 ;
but the necessity of admitting a difference in the constitu-
tion of the atom of water in the three states in which it is
found, is sufficiently indicated independently of all system,
by comparing the specific heat of equal weights of water,
vapour and ice. For the specific heat of vapour ought to be
1*225, taking that of an equal and constant volume of air
as unity ; and calculating from this, and taking as unity
that of an equal weight of water, we have -3753 according
to Delaroche and Berard, while the specific heat is 1, and
that of ice is *92.

2. Oxides — (1). In this class, according to the theoreti-
cal considerations which we have been discussing, it is
necessary to view those oxides consisting of one atom base
and one atom oxygen, as being formed of J atom oxygen
and 1 atom of base ; but in order to correspond with the
law already announced, the atom in the solid state will
consist of \ atom base and J atom oxygen. Thus, in the case
ofthe protoxide of lead, the weight ofthe atom of lead being
6*5 or half of that commonly adopted ; taking oxygen as unity,
the atom ofthe protoxide will be 3*25 -t- 0*25 = 3*5 ; its con-

1835.] Heat of Bodies to their Atomic Weights. 41

stituent number is, \ -\- \-= -lb, the square root of which is,
•866 X -1875 = 1624 -r 3-5 = -464, the calculated specific
heat, which differs very slightly from -49 or '50, the results
of experiment.

To obtain, therefore, the specific heat of oxides thus con-
stituted, it is only necessary to divide the weight of the
compound atom of each oxide by the number -1624. But
it is the double of this number or -3248 that it is necessary
to divide by the atom, resulting immediately from the
union of a whole atom with half an atom of oxygen; to ob-
tain the pame specific heat.

By the application of this number we obtain for the cal-
culated specific heats of the oxides of mercury, zinc, and
copper, 0'048, 0*129, and 0*130, while the experiments of
Neumann gave *049, 0*132, 0*137. A similar calculation
affords for the protoxide of lead, protoxide of tin, and lime,
*047, *078, 0* 182, the results of experiment being *050, -094,
and -179. The calculated specific heat of magnesia is '251,
that of experiment *276.

Neumann makes this constant number '697, the half of
which is *3485, constituting what he terms a stechiometrical
quantity. This is considerably above the estimate of
Avogrado. The difference is ascribed by the latter, to the
circumstance of Neumann taking as a basis of his calcu-
lation, the specific heat of magnesia, which has not been
properly ascertained.

(2.) Those oxides which consist according to our present
ideas of 1^ atom base and 1 atom oxygen, are considered
by the views of Avogrado as compounds of | atom oxygen
and 1 atom base; to this class belong peroxide of iron,
deutoxide of lead, arsenious acid, and perhaps alumina.
The specific heat of alumina by experiment was found to be
*2. Now supposing the solid atom of alumina to consist of J
atom aluminum and f atom oxygen, the calculated specific
heat would be *2185. New experiments are required upon
pure specimens of peroxide of iron and arsenious acid,
before any conclusion can be come to with regard to the
constitution of these atoms. But in reference to magnetic
iron which consists of 1 atom protoxide, and 2 atoms per-
oxide of iron, important data have been obtained. If we
consider the atom of this substance divided into 8 portions
so that the solid atom may be f F + -JO, the weight of

42 On the Relation of the Specific [July

the atom will be f 1*696 H- i = 0-886. Its constituent
number will be ^ + i^ = f = 0*625, the square root of
which is 0*7905 X *1875=*1482. Therefore i^^ == -1672,
the calculated specific heat. Neumann found the specific
heat of this substance to be by experiment -1641.

(3.) The last class of oxides are those which, according
to the present views, consist of 2 atoms of oxygen and 1 of
base. The principal examples are peroxide of tin, binoxide
of manganese, which, by the law of Avogrado, should be
formed of 1 atom oxygen and 1 atom base. The calculated
specific heat of peroxide of tin is -1134, while the result of
experiment was '895 and -965 according to Neumann.

On the Continent silica is referred to this class. The ap-
plication of Avogrado's law, however, shews us that the
atomic number and view of the constitution of this sub-
stance adopted by Dr. Thomson, is the correct one, viz.
that it consists of 1 atom silica -|- 1 oxygen, for 2 being
the atomic weight, the half of which is 1, then the consti-
tuent number is — - — = 1, the square root of which is 1.

We have therefore ^i|^ = '1875. Neumann found by
experiment the specific heat to be for quartz and rock crystal
•1894 and *1883. If we adopt the continental number *9625
for the atom of silica, the calculated specific heat is '1948.

3. Sulphur ets. — The observations of Avogrado and Neu-
mann go to prove that the atom of the sulphurets should
be divided. Thus for cinnabar the specific heat calculated
upon these hypothesis is *511. Neumann found it by ex-
periment to be *520; for galena the calculated specific heat
is '0501, by experiment *053 and -046 ; for blende the cal-
culated number is -1241, experiment -1145; for realgar
calculation gives -1117, experiment '1111. These four
sulphurets, according to Neumann, afford *757 for the con-
stant number which expresses the product of their observed
specific heat, multiplied by the weight of the atoms result-
ing immediately from the union of an atom of each. Accord-
ing to Avogrado, this number is *7484, now the fourth of
the latter number is -1871, which differs but slightly from
•1875, the half of the co-eflftcient of Dulong and Petit.
Avogrado has found that the same law applies to orpiment
and bisulphuret of iron.

4. Chlorides. — The atom of chloride of sodium will require

1835.] Heat af Bodies to their Atomic Weights, 43

to be considered as consisting of ^ atom sodium and 1
atom chlorine. The calculated specific heat will then

be ^ — = '214, the experimental result was •221.

The atom of Chloride of mercury or corrosive sublimate,
if viewed as constituted of I an atom mercury and 2 atoms
chlorine, will yield the following result : —

- 4.05 = '0693. Now the number derived from

experiment was -069. The number calculated from the
atom adopted on the Continent would be '0694.

The atom of potassium, Avogrado considers ought to be
reduced to the fourth of what it is at present. The chloride
of potassium would then consist of 2 atoms chlorine -h 1

potassium. Hence we have ^ — = -193. There-

1.10 /o

suit of an experiment by Avogrado was '184. If we adopt
the continental number for potash, we should have -197 as
the calculated specific heat.

5. Salts. — Avogrado determined the specific heat of five
sulphates in the anhydrous state, and Neumann has obtained
the specific heat of four mineral sulphates. In these, it is
necessary to consider the atom as consisting of -J atom of
oxide and ^ atom sulphuric acid. The following table ex-
hibits the specific heat of six different sulphates, ascertained
by calculation and experiment.

observed, calculated.

Sulphate of lime ..... 0-188 - 0.175

iron 0-145 - 0-160

" copper .... 0-180 - 0*167

barytes .... 0-108 - 0-103

" strontian ... 0*136 - 0-131

lead 0-085 - 0-079

The sulphates of soda and zinc would require to be
divided by 8, but their specific heat has not been properly
ascertained. Neumann found by an examination of the
sulphates that the stechiometrical numbers, that is the pro-
duct of the specific heat multiplied by the comjpound atom,
was 1*546. Reducing the atoms to one half, according to
the view of Avogrado, we obtain -773 for the number,

44

On the Relation of the Specific

[July

and •1932 the fourth of the latter, which does not differ
much from '1875.

In carbonate of lime thenumberof atoms are indicated by
the formula, 1+1 + ^ + 1=3, which being divided by
4, gives -75, the square root of which is 0*866 x 1875 =
•1624. Now taking the 8th of the atom of carbonate of
of lime we have %\\%\^ = 0-207. The specific heat by
experiment was found to be '203. The stechiometrical num-
ber deduced from an examination of the carbonates is
•1892. The correspondence of the calculated and observed
specific heats of the carbonates is presented in this table.

observed, calculated.

Carbonate of lime . .

0-2011

- 0-2058

j»

iron . .

0^1819 .

- 0-1818

zinc . .

0-1712

- 0-1668

■

barytes

0-1078

- 0-1055

J

strontian .

0-1445

- 0-1408

^

lead . .

0-0814

- 0-0778

lime & magnesia

0-2161 -

0-2230

magnesia &

iron

0-2270 -

0-2264

6. Minerals. — Neumann has determined the specific heat
of several natural silicates. Common felspar, according to
the views of Avogrado, will consist of 1 atom potassium
and ^ atom oxygen forming potash ; 1 atom aluminum + f
atom oxygen forming alumina, and 3 atoms silicon + 3
atoms oxygen forming silica, or altogether 1 atom potas-
sium + 1 aluminum + 3 silicon + 4 oxygen. If the weight
of the atom be 8-8537, and the constituent number 9, then
we have for the latter number the expression |^, the square
root of which is 1-0608 x '1875 = '1989, and the atom is
reduced to - \^.^ ^ = 1-1067; the calculated specific heat is
tlien 7^^ =-1797. Neumann found -1911 by experi-
ment, and -1861 for adularia. In the case of albite or
soda felspar, it is necessary to consider the atom divided by
16 . its constituent number will be (taking for a numerator
17 made up of 1 sodium + 2 aluminum -f 6 silicon -f 8
oxygen = 17,) fj, of which the square root is 1-0308 x
-1875 = 1937, the weight of its atom is ^-^p^ = 1-0446,
and the calculated specific heat is rirr-^ = 0-1851. Neu-

■,., . A. 0445

mann obtamed by experiment -1961.

Hydrous sulphate of lime affords by calculation for the
specific heat -259. Neumann found it -2727.

1835.] Heat of Bodies to their Atomic Weights. 45

We terminate for the present this interesting subject
by two observations.

1 . The co-efficient of the law which marks the relation
between the specific heat and atomic weight, differs slightly
in different substances. It is in the

Oxides ...... 1914

Sulphurets .... -1871

Sulphates -1932

Carbonates . . . . '1892

Mean 1902

This mean is to 1875 nearly as 71 to 70.

Neumann has found for sulphur the co-efficient '209,
which approaches -2085, the number of Lavoisier and
Laplace. Hence, it is probable that the co-efficient for non-
metallic substances may be a little greater than for metallic
bodies.

2. We may likewise deduce from the researches of
Avogrado and Neumann that the atoms of bodies are related
according to a regular law, and that the accuracy of the
atomic numbers adopted in this country is confirmed in
many instances.

Article VII.
Ascent of Chimhorazo, on the \Qth December 1831 .

By M. BOUSSINGAULT.''^

After ten years of assiduous labour I had realized the pro-
jects of my youth, which had brought me to the new world.
The height of the barometer at the level of the sea between
the tropics, had been determined in the port of La Guayra.
The geographical position of the principle cities of Vene-
zuela and of New Grenada, had been already fixed. Nume-
rous observations, by levelling, had informed us of the figure
of the Cordilleras, and I had procured the most precise data
in reference to the position of the gold and platinum of
Antioquia and Choco. In short, my laboratory had been
successively erected in the different craters of the volcanoes

* From the Annales de Chimie, Iviii. 150.

46 M. Boussingault's [July

in the neighbourhood of the equator ; and I had been fortu-
nate enough to be able to continue my researches upon the
decrease of the heat in the intertropical Andes to the great
height of 5500 metres (17,040 feet).

I found myself at Rio Bamba, resting myself, after my
recent excursions, to Cotopaxi andTunguragua. I wished to
contemplate at my leisure, to satiate myself, as it were,
with the view of the majestic glaciers, which have so often
attracted the attention of scientific men, and to which it
was necessary that I should soon bid an eternal farewell.

Rio Bamba is, perhaps, the most singular diorama in the
world. The town presents nothing remarkable in itself:
It is placed on one of those arid plateaus so common in the
Andes, and which have all, at this great height, a charac-
teristic wintry aspect, which fills the traveller with a feeling
of melancholy. It is true that, in order to reach it, he
must traverse a most picturesque region, and it is always
with regret that he exchanges a tropical climate for the
northern frosts. From the house in which I resided I could
survey Capac-urcu, Tunguragua, Cubille, Carguairazo, to
the North Chimborazo, and several other celebrated moun-
tains of Paramos, which, although free from eternal snow,
are of high geological interest.

This vast amphitheatre of snow, which limits on every
side the horizon of Rio Bamba, is a continual subject for
observation. It is curious to notice the appearance of these
glaciers at different hours of the day, to see their apparent
height, varying from one instant to another by the effect of
atmospheric refraction. With what interest does not one
view, in such a circumscribed space, the appearance of all
the great meteorological phenomena. Here may be seen
those immense clouds which Saussure has well defined by
the denomination of parasitical clouds, and are distinguished
by their attaching themselves to the middle of a trachyte
cone. There they stick, uninfluenced by the wind, which
blows powerfully upon them. But soon the lightning shines
through the midst of the mass of vapour, and hail, mixed
with rain, inundates the base of the mountain, while its
snowy summit, which the storm cannot reach, shines re-
splendent with the rays of the sun. At a distance there is
a line of ice shooting forwards, shining brilliantly like a

1835.] ^scent of Ckimhorazo. 47

mirror. The atmosphere is remarkably pure, for, although
the snowy ridge appears covered with a cloud which seems
like smoke to emanate from it, yet it is merely a vapour,
which soon vanishing away, re-appears again, and is always
of an ephemeral nature. This formation of clouds at
intervals is a very frequent phenomenon on the tops of snowy
mountains. They appear principally in calms, and always
some hours after the culmination of the sun. In these
circumstances the glaciers may be compared to condensators,
pointing towards the upper regions of the atmosphere, which
serve to dry the air while cooling, and to return the water
to the surface of the earth, which is dissipated in the state
of vapour.

These plateaus surrounded by glaciers, present sometimes
a most melancholy aspect, for when a continued wind brings
up the moist air from the hot regions, the mountains become
invisible, and the horizon is obscured by a line of clouds
which seem to touch the earth, and the day is cold and moist;
this mass of vapour being impervious to solar light.

The twilight then is long. At other periods, as over the
equatorial zone, night succeeds the day quite suddenly;
the sun may be said to be extinguished in setting.

I could not terminate my researches upon the trachytes
of the Cordilleras more properly than by a careful exami-
nation of Chimborazo. But what chiefly stimulated me to
pass the snowy limit, was the desire of obtaining the mean
temperature of a very elevated station. And although this
expectation was frustrated, my excursion, I hope, will not
be found devoid of utility to Science.

I explain the reasons which induced me to ascend Chim-
borazo thus particularly, because I disapprove of dangerous
excursions on mountains, when they are not undertaken in
the cause of Science. For notwithstanding the numerous
ascents of Mount Blanc since the time of Suassure, he
appears to me the only one who attained its summit.*

My friend Colonel Hall, who had already accompanied
me to Antisana and Cotopaxi, wished to join in the present
expedition, in order to increase the numerous facts which

* Colonel Beaufoy, who ascertained the latitude on the summit of Mount Blane,
must certainly be separated from" the list of mere narrators of hair-breadth escapes.
See Ann. of Philosophy, ix. 97. — Edit.

/

48 M, BoussingauW s [July

he had already ascertained relative to the topography of
the province of Quito, and to continue his researches upon
the geography of plants. From Rio Bamba, Chimborazo
presents two declivities of very different inclination. One
looking upon Arenal is very abrupt, and exhibits, under
the ice, numerous points of trachyte. The other, which
descends to a place called CA^/ZapwZZM, near Mocha, possesses,
on the contrary, a slight inclination, but is of considerable
extent. After an attentive examination of the neighbour-
hood of the mountain we resolved to ascend by this route.

On the 14th December 1831, we lodged in the farm of
Chimborazo, where we were fortunate in having some dry
straw to repose on, and some sheep skins to protect us from
the cold. The farm is situated at an elevation of 3800
metres (12,464 feet).

The nights are cold, and the stay here is rendered more
disagreeable in consequence of the scarcity of wood. We
were already in that region of grasses (Pajonales), which
is passed before arriving at the limit of perpetual snow, and
which terminates the woody vegetation.

On the 15th, at 7 o'clock in the morning, we proceeded
on our journey under the guidance of an Indian of the farm.
The Indians of the plains are generally very bad guides,
for, as they seldom ascend to the limit of the snow, they
possess a very imperfect knowledge of the roads which con-
duct to the ridge of the glaciers. We followed, at first, the
bed of a stream which was enclosed by walls of trachyte,
whose waters were derived from the glaciers ; but we soon
quitted this chasm, and directed our course towards Mocha,
along the base of Chimborazo . We gradually rose ; our mules
walked with diflficulty amid the debris of rocks which were
accumulated at the foot of the mountain. The difficulty
rapidly increased ; the soil was loose, and the mules stopped
almost at every step, to take a long rest ; they no longer
obeyed the spur ; their breathing was short and quick. We
were then exactly at the height of Mont Blanc, the baro-
meter indicating an elevation of 4808 metres* (15,770 feet)
above the level of the sea. After covering oiir faces with
masks of light muslin, in order to protect ourselves from
the accidents which had occurred to us on , Antisana, we

• The height of Mount Blanc is 4810 metres (15,776 feet.)

1835.] Ascent of Chimborazo. 49

began to clamber over a ridge which bordered on a very
elevated point of ice. It was mid-day. We ascended slowly,
and as in proportion to our progress over the snow we expe-
rienced greater difficulty in breathing, we readily regained
our strength, by stopping every eight or ten steps without
always sitting down. At an equal, height I think I have
remarked, that there is greater difficulty in breathing on
snow than on a rock. I shall endeavour, afterwards, to
explain the reason of this. We soon attained a black rock,
situated above the ridge which we had surpassed. We
continued to rise during some time, but not without under-
going great fatigue, from the want of consistence in the
snowy soil, which yielded to our feet, and in which we
sometimes sunk up to the middle.

Notwithstanding all our efforts, we were soon convinced
that it was impossible to advance, as a little above the
black rock the soft snow was more than four feet deep.
We lay down on a mass of trachyte which appeared like an
island in the middle of a sea of snow. We had reached an
elevation of 5115 metres (16,777 feet). The temperature
of the air was 2*9 (37-2 F.). It was now 1 J P. M. Thus
after much fatigue we had only ascended 307 metres (1006
feet) above the place where we started. I filled at this
station a bottle with snow for the purpose of making a
chemical examination of the air contained in its interstices.
The object in view will be subsequently explained. In a
few minutes we descended to the place where we had left
our mules. I occupied a short time in examining the
geology of this part of the mountain and in collecting
specimens of the rocks. At half-past three we started and
at 6 o'clock reached the farm. The scene was splendid, Chim-
borazo never appeared so majestic as at this period ; but after
our failure we could only gaze on it with a feeling of regret.

We resolved to attempt the ascent by the abrupt side,
that is to say, by the declivity which looks towards Arenal.
We knew that it was by this side that Humboldt had
ascended the mountain. The spot which he reached had
been pointed out to us from Rio Bamba, but it was impos-
sible to obtain correct information of the route which he
had followed, to enable us to reach it, as the Indians who
had guided this intrepid traveller were all dead.

VOL. II. E

60 • M. Boussingaulfs [July

It was at 7 o'clock on the morning of the 16th, that we
hegan to ascend by the route of Alenal. The sky was
remarkably clear. To the east we observed the famous
volcano of Langay, situated in the province of Macas, and
which, only a century ago, Condamine had seen in a state
of permanent eruption. In proportion as we advanced, the
ground became elevated in a sensible manner. In general
the plateaus of trachyte, which supported the isolated
peaks, of which the Andes consist, rise gradually towards
the base of these peaks. The numerous deep crevices which
furrow these plateaus appear to diverge from a common
centre and become narrower in proportion to their distance
from the centre. They exactly resemble the cracks which
are observed on glass which has been starred. At 9 o'clock
we halted to breakfast under the shade of an enormous
block of trachyte, to which we gave the name of Pedron del
Almuenzo.

Here I made a barometrical observation, because I was
in hopes of being able to take another at 4 P. M., in order
to ascertain at this height the diurnal variation. Pedron
is elevated 4335 metres (14,218 feet). We passed on our
mules the limit of the snow. When we began to ascend on
foot the height was 4945 metres (16,219 feet). The ground
was quite unfitted for our mules to travel on. These
animals endeavoured to make us comprehend by their
instinct the lassitude which they endured; their ears
generally so erect and attentive were completely flattened,
and during the frequent halts which they made, in order
to breathe, they gazed anxiously on the plain beneath.
Few persons have, it is probable, rode to such an elevation ;
for in order to keep one's seat, on animals travelling in
such soft ground, it would be necessary to have been
accustomed to ride for several years among the Andes.
After examining the place where we had stopped, we
endeavoured to gain a ridge which mounted to the summit
of Chimborazo. It was necessary in the first instance to
overcome a great declivity which lay before us ; it was
formed principally of blocks of rock of all sizes, disposed in
a shelving manner ; these and their fragments of trachyte
were covered by larger or smaller pieces of ice, and in
several places, it was obvious that this debris rested on

1835.] Ascent of Chimborazo. 51

hardened snow. It was derived from recent ruptures which
had taken place in the upper parts of the mountain.
These ruptures are frequent, and in the midst of the glaciers
of the Cordilleras, there are avalanches in which there are
more stones than snow. It was three-quarters past ten
when we left our mules ; as we walked upon rocks we
experienced no great difficulty. It might be said that we
mounted a ladder in bad condition. The only trouble was
in looking for stones on which we might tread with safety ;
we stopped to breathe every six or eight steps, but without
sitting down, and even this rest was made use of for col-
lecting geological specimens. But whenever we reached a
sunny surface the heat of the sun became suffocating, our
respiration difficult, and consequently our rests more fre-
quent and more necessary.

At 111 A. M., we crossed an extensive table of ice in
which it was necessary to make notches in order to secure
our footing. This passage was dangerous ; a step would
have cost us our lives. We again reached debris of trachyte.
It felt like terra firma and enabled us to ascend a little
more rapidly ; we walked in a column, first myself, then
Colonel Hall, and lastly the negro, who followed our steps
exactly, to secure the safety of the instruments which were
intrusted to him. We preserved complete silence at this
time ; for experience had taught us that nothing is more
weakening than a conversation kept up at this altitude,
and when we rested, if we exchanged words, we spoke in
the lowest tone of voice. It is in a great measure to this
precaution that I attribute the state of health which I have
constantly enjoyed during my ascents to the volcanoes.
This salutary restriction I imposed in a despotic manner
upon all those who accompanied me. Upon Antisana, an
Indian, vi^ho had neglected this order, and had called upon
Colonel Hall (who had wandered during our passage
through a cloud) with all his strength of lung, was seized
with vertigo and incipient hemorrhage. We soon reached
the ridge which we wished. It had not the same appear-
ance which it presented at a distance. It contained little
snow, but it possessed escarpments which were difficult to
ascend. We were obliged to make extraordinary efforts,
and exertion is painful in these elevated regions. At last

E 2

52 ' M. Boussingaulfs [July

we arrived at the foot of a wall of trachyte surmounted by
a peak which was several hundred metres in height.

This was discouraging, although the barometer only
indicated an elevation of 5680 metres (18,630 feet). This
height was not great for us, because it was inferior to that
which we had reached on Cotopaxi. Humboldt had
ascended higher on Chimborazo, and we were anxious at
least to reach the station which that distinguished traveller
had attained. Mountain travellers, when discouraged, are
very apt to sit down, a plan which we followed at Pena
Colorada (red rock). This was the first time we had in-
dulged ourselves with a seat. We felt extremely thirsty,
and were first occupied in sucking the ice to quench our
thirst. It was three-quarters past noon, and yet we felt
very cold. The thermometer having sunk to 0°-4 (32^°).
We were enveloped in a cloud ; the hair hygrometer stood
at 91 J°. The vapour disappeared and the hygrometer re-
mained at 84°.

So much moisture may appear extraordinary at such a
height, but it constantly occurs among the glaciers of the
Andes, and appears to admit of a very natural explanation.
During the day the surface of the snow is generally moist ;
the rock of Pena Colorada, for example, was all wet.
Hence, the air near the glacier must then be saturated with
moisture. On Mount Blanc, Saussure found the hygro-
meter at 59° and 51°, the temperature varying from 0*5 to ■
— 2°3 R. (33°1 to 26°-82 F.)

Now, it is not uncommon to observe at the same level of
the sea a similar hygrometrical state of the atmosphere.
In the Cordilleras great dryness is experienced at 2000
and 3500 metres (7,560, 11,480 feet). At Quito and Santa
Fe de Bogota, we have seen, as I have noticed in another
place, the hygrometer of Saussure descend to 26°.* The
accidents which persons frequenting the glaciers have ex-
perienced, especially the very frequent alteration of the skin
of the face, cannot be ascribed, therefore, to the acid nature
of the air. This change appears to me attributable to the
action of strong light, since to protect the skin from chop-
ping, it is sufiicient to cover the face with a simple coloured

* Researches into the cause of Goitre. Ann. de Chemie et do Physique.

1835.] Ascent of Cidmborazo. 63

crape. It is obvious that such a slight fabric cannot pre-
serve the skin from the contact of the air, but it may
diminish the strength of the light to which one is exposed.
When the sun shines on a snovry plain, I have been told
that it is only necessary to blacken the face. I am the more
inclined to believe this because the negro who accompanied
me to Antisana, having like myself neglected to wear a
veil, was seized with a violent inflammation of the eyes,
while the epidermis of his face was not injured, and mine
was completely destroyed.^

When the cloud in which we were enveloped was dissi-
pated, we examined our situation. Looking at the red rock
we had on our right a tremendous gulf. On our left, to-
wards Arenal, an immense rock was distinguished, which
it was necessary to reach in order to ascertain if the red
rock could be passed, and to see if we could proceed further.
The access to this belvidere was rough : I reached it however
with the assistance of my two companions. I observed that
if we could clamber over an inclined surface covered with
snow, on the side of the rock opposite to that on which we
had approached, we might attain a more considerable eleva-
tion. In order to have an accurate idea of the topography
of Chimborazo, let one figure to himself an immense rock
supported on all sides by props ; the angles are the props
which, from the plain, appear to support this enormous
block.

Before undertaking this dangerous passage, I ordered
my negro to try the state of the snow. It possessed con-
venient consistence. Hall and the negro endeavoured to
turn round to the position which I occupied, and I
endeavoured to rejoin them, when they had gained a suffi-
cieiitly secure footing to receive me ; for to accomplish this
it was necessary to slide down a descent of 25 feet over the
ice. Just when we were preparing to set out, a stone was
detached from the upper part of the mountain and fell near
Colonel Hall. It met with a check which changed its
course. I thought he was wounded, and could not be con-

* The action of the light appears to be the true explanation of the disagreable
effect described. I have seen troublesome inflammation of the conjunctiva in-
duced in seamen, by incautiously sleeping on deck, with the face exposed to the
influence of the light of the moon and stars ; sailors call it star blindness. — Edit.

64 ' ■ M. BoussingauW s [July

vinced of the contrary until I saw him lift it up and examine
the specimen which had been so dangerously submitted to
our notice. It was of the same nature as that which we
trod upon. We proceeded cautiously. On the right we
could support ourselves on the rock. On the left the
declivity was frightful, and before advancing we were ob-
liged to familiarize ourselves with the precipice. This is
a precaution which ought never to be neglected in moun-
tains, whenever a dangerous chasm is to be passed. Saussure
has said so long ago ; but it cannot be too often repeated,
and in my perilous journeys among the summits of the
Andes, I have never lost sight of the good advice.

We now began to feel more than hitherto the effect of
the rarefaction of the air. We were obliged to stop every
two or three steps, and often even to lie down for some
seconds. We only experienced difficulty when moving ; the
snow soon presented a condition which rendered our
journey equally slow and dangerous. It was only three or
four inches deep, and under it existed a very hard and
slippery ice. We were obliged to make depressions in the
ice in order to ensure our footing. The negro went first
to form this ladder ; but he was soon exhausted. Wishing
to take his place, I slipped, when fortunately for me, I was
powerfully retained by Hall and my negro. At one time
we were all three in eminent danger. This accident made
us hesitate a little, but plucking up new courage we resolved
to advance. The snow became more favourable. We made
a last effort, and at three-quarters past one we reached the
desired point. Here we were convinced that it was impos-
sible to do more. We found ourselves at the bottom of a
prism of trachyte, whose top covered with a cupola of snow,
forms the summit of Chimborazo.

The point which we had attained was only a few feet
broad. On all sides we were surrounded by precipices.
The deep colour of the rock offered a striking contrast with
the whiteness of the snow. Long icy stalagmites appeared
in suspension over our heads, as if a mighty cascade had
been congealed. The prospect was admirable. A few
small clouds could be observed towards the east ; the air
was perfectly calm ; our view was very extensive ; the situa-
tion was new, and we enjoyed the most lively satisfaction.

1835.] Ascent of Chimborazo. 55

We were at an elevation of 6004 metres (19,699 feet,)
which is I believe the greatest height that man has attained
on mountains.

At 2 P M. the barometer stood at 371 '"'« 1 (13 inches
8J lines), the attached thermometer indicated a tempera-
ture of 7°-8 (46° F.) Under the shade of a rock the
detached thermometer stood at the same point. I en-
deavoured, but in vain, to find a cave in which I might
take the mean temperature of the station. At the depth
of one foot under the snow the thermometer stood at 0°
(32°), but the snow had melted and the instrument there-
fore indicated the temperature of the melted snow.
(To he continued.)

Article VII.

Examination of Hair Salt, or Native Sulphate of Alumina
and Iron. By Robert D. Thomson, M.D.

The salt known under the name of hair salt and feather
alum, which is produced by the decomposition of strata
containing iron pyrites, has been examined by different
chemists; but hitherto no definite composition has been
assigned to it, notwithstanding the length of time which
has elapsed since it was first noticed.

Dioscorides presents us with a detail of its characters so
striking as to prevent any mistake in identifying it.''^ He
describes it as being very white, astringent, in capillary
portiofts, whichTesemble what was called in Egypt trichitis.
Pliny likewise mentions it particularly : ** Concreti," says
he, " aluminis unum genus schiston appellant Graeci, in
capillamenta queedam canescentia dehiscens. Undequidem
trichitin potius appellavere. Hoc fit e lapide ex quo et
chalcitin vocant," &;c.J

The indefatigable Tournefort visited the island of Milo,
from which the salt described by these ancient authors was
derived, and has satisfied us that the characters, as given
by Dioscorides and Pliny, are quite accurate.f

1. Klaproth examined a salt of a greyish-white colour

* V. 323, ijcvTTTTipia Tpt\tTLQ. X Plin. Nat. Hist. xxxv. 15.
t Tourneibrt's Voyage, i. 177.

56 Dr. R. D, Thomson on Hair Salt, or [July

becoming yellow by exposTire to the air, occurring in alum
slate, and found its chemical composition to be

Protoxide of iron .

. . 7-60

Potash ....

•25

Sulphuric acid and water 77*

100-*

If

we consider the alumina and iron

to be saturated the

constituents will be,

Alumina . . .

. 15-25 7

Protoxide of iron

. 7-5 1

Sulphuric acid .

. 41-77 8

Water ....

. 35-48 31

lOO-OOf
equivalent to 7 Al.S. + /S. + 31 Aq.

2. The same chemist states that the hair salt from the
mercurial mines of Idria, (Halotrichum Scopolii), found in
alum slate, possesses a silvery white colour, and consists
essentially of sulphate of magnesia, united with a small
portion of sulphate of iron. According to a recent analysis
hair salt from Idria consists of

Magnesia .... 16*389 - 1 atom.
Protoxide of iron . 0-226 -
Sulphuric acid . . 32-303 - 1 ,, ,
Water 50-934 - 7 atoms.

99-852f
which answers to MS. -f- 7 Aq. mixed with a little sulphate
of iron, agreeing exactly in composition with the right
prismatical crystals of the common Epsom salt. A similar
mineral from Calataynd, in Arragon, yielded,

Magnesia .... 16*495
Sulphuric acid . . 31*899
Water 51*202

99-596

* Beitrage, iii. lOS, Chemische Untersuchung des federalauns von Freyen-
walde.

t Beitrage, iii. 104.

X Poggendorff, Annalen, xxxi. 144.

1835.] Native Sulphate of Alumina and Iron, 57

3. Berthier has published the analysis of a hair salt,
(Thomson s Inorganic Chemistry, ii. 768.) consisting of
Sulphuric acid . . . 34*4
Protoxide of iron . . 12*

Alumina 8*8

Magnesia 0*8

Water 44*

100-
corresponding with 1 J Al. S. + /S. + 15 Aq.^

4 In the course of an excursion to the eastern parts of
the colony of the Cape of Good Hope, H. Hertzog discovered
two hair salts in a cave on the Bushman River, 200 feet
above its bed, in 30° 30' S.L. and 26° 40' E.L., twenty miles
from the sea. The cave was thirty feet wide, seven feet high,
and twenty deep, having its upper part coated with feather
alum, presenting the appearance of gypsum. The salt is
snow-white, fibrous, with a silky lustre, the darker coloured
fibres being very elastic. The fibres are partly straight and
partly bent. The mineral consists, according to H. Stro-
meyer, of

Alumina 11*515

Magnesia 3-690

Protoxide of manganese 2*167
Sulphuric acid . . . . 36*770

Water 45*739

Chloride of potassium . 0*205

100*086t
which is expressed by

2J Al. S* + (i M. + 1 mn.) S. -f 20^ Aq.
Under the alum a bitter salt is found, which is frequently
crystallized in four-sided prisms, and when pure, is white.
The mass accompanying the bitter salt is weather-beaten,
earthy, and has a slaty appearance, and a greenish-white
colour. It contains scales of mica, or talc, which are
parallel with its cleavage. H. Stromeyer found it to con-
tain silica and alumina in considerable quantity ; very little

* Ann. des Mines, v. 259. t Poggendorff, Ann. xxxi. 142.

58 Dr. R. D, Thomson on Hair Salt, or [July

iron, much manganese, and one per cent lime and magnesia.

Water extracts from it common salt, gypsum, bitter

salt, sulphate of manganese, and a trace of sulphate of

alumina.

The salt itself consists of

Magnesia 14-579

Protoxide of manganese 3*616
Sulphuric acid .... 32-258
Water 49-243

99-696
corresponding with

11 MS. -t- m?z S. + 91 Aq.

The rock on which the salt lies is a granular schistose
quartzose rock of a greenish-gray colour, with small silvery
scales of mica, and is impregnated with the salt matter
which covers partly the surface with flakes, and partly
incrusts it. The flocky portion consists of bitter salt, the
crust of alum, with a small quantity of bitter salt. The
rock on which the river flows is a granular gray quartz,
with some small scales of mica. The roof of the cave con-
sists of red conglomerate, in which rolled quartz occurs,
and occasionally pyrites and oxide of iron. The neighbour-
hood is formed of hills 800 feet high, which are intersected
by deep vallies, and capped by limestone. This limestone
contains small portions of carbonate of magnesia, with
traces of manganese and iron. Fossil oyster, and muscle
shells were observed on the upper part of the hill, between
Uitenhage and Enon. Hence, it would appear to be a very
recent tertiary formation. It is worthy of notice that the
alum and bitter salt are formed separately, and that neither
of them contain iron, although the oxide of that metal
occurs abundantly in the conglomerate. The feather alum,
according to Hofrath Stromeyer, is a new hitherto unde-
scribed species of alum, in which the sulphate of alumina
occurs in combination with sulphate of manganese and
sulphate of magnesia. Hence, he terms it mangan-magnesia
alum. Sulphate of manganese has never previously been
detected in any species of alum.

At Tschermig, in Bohemia, an ammoniacal alum is found,
which, according to Lampadius and Gruner, consists of

1835.] Native Sulphate of Alumina and Iron, 69

Alumina 11*602

Ammonia 3*721

Magnesia 0*115

Sulphuric acid .... 36*065

Water 48*390

99*893*

The stalactitical bitter salt of Neusohl, in Bohemia,
contains

Magnesia 15*314

Oxide of cobalt ' . . . 0*688

Oxide of copper . . . 0*382

Protoxide of manganese 0*343

Protoxide of iron . . . 0*092

Sulphuric acid . . . . 31*372

Water 51*700

99*891 1

5. The substances which have been already described are
all derived from foreign localities. I now proceed to relate
the facts which have been ascertained with respect to the
hair salts of this country.

Mr. Phillips subjected to examination the salt which
proceeds from the decomposition of iron pyrites in the shale
of the deserted coal mines of Campsie and Hurlet, in the
neighbourhood of Glasgow. He obtained

Sulphuric acid . . 30*9 - 3*07 atoms.

Protoxide of iron . . 20*7 - 2*3

Alumina . . . . 5*2 - 1*15

Water ..... 43*2 - 19*2

»j

>»

100*0
The formula deduced from his analysis is
2/S. + A1.2 S.'+ 16f Aq.J
He repeated the analysis, and obtained the sulphuric
acid in excess.

The conclusions at which I have arrived, after making
several careful analyses, are, that the substance is by no

♦ PoggendorfF, Ann. xxxi. 142. t Ibid.

% Annals of Philosophy, Second Series, v. 446.

60

Dr H. D. Thomson on Hair Salt, or

[July

means a steady compound, as I have never obtained the
same quantity of alumina, and have found that of the
acid to vary considerably. That the latter is often in excess
is evident, from the salt tasting sour in many instances,
while at other times it is nearly tasteless. Mr. Phillips
informs us that he found the proportion of alumina less,
in a second trial which he made, than in his first analysis,
although the difference was not so considerable as to in-
duce him to repeat his experiments.

The specimens which I examined were from Campsie,
and consisted of silky, albestus-like threads, mixed with
pieces of shale and sulphate of iron, which were carefully
excluded before dissolving the salt.

It is very soluble in water, and often possesses a styptic
taste, from the presence of minute portions of sulphate of
iron ; 5 grs. introduced into a platinum crucible, and exposed
to the heat of a spirit lamp, lost, without altering in colour,
2-13 grs. By an additional heat, which rendered the salt
reddish, 0-03 disappeared. If we suppose that all the water
was expelled in the first experiment, without decomposing
the compound in any degree, we obtain a per centage of
42*6 ; by the second we have 43*6.

The following table contains the result of three analyses
of hair salt from Campsie :

Sulphuric
Acid.

Protoxide of
Iron.

Alumina.

Water.

1.

2.
3.

32-925
28-635
33-580

19-800
19-935
19-620

2-500

2-850
3-200

44-775
48-580
43-600

Mean . . .
Atoms . . .

31-713
6-34

19-785
4-39

2-850
1-26

45-651
40-5

In these experiments the composition is,
First.
Sulphuric acid . . 6' 5
Protoxide of iron . . 4-4
Alumina . . . . 1*1

Water 39-8

To represent the composition by these analyses, we have
the formulae respectively : —

Second.

Third.

5-727

- 6-71 atoms

4-4

- 4-35

1-26

- 1-42

43-18

- 38-75

1 835 . ] Native Sulphate of A lamina and Iron . 61

1. 4/S. + Al. S2 + 36 Aq.

2. 3J/S'. + Al. S. + 341 Aq.

3. 3/'S. + Al. Sii+27i Aq.

And, as expressing the mean, we may adopt
3i/S'. + Al. SU 4- 32 Aq.

Another specimen which had been preserved in a phial
for some years was also analyzed, and yielded.

Sulphuric acid . . 35-600 - 2-37 atoms.
Protoxide of iron . . 13-500 - 1* ,,

Alumina .... 7-127 - 1-05 „
Water 43-773 - 12-9

100-000
Which may be considered equivalent to/ S. + Al. S. +
13 Aq. with a great excess of acid. The salt had a strongly
acid taste. If we take the mean of this formula with those
which precede, we obtain nearly

2/S. + Al. S. + 20 Aq.
which is quite different from the result of Phillips.

Of the three analyses contained in the table, the third,
perhaps, approaches most nearly the mean composition of
this substance, as it corresponds with the first so far as
regards the acid and iron, and the water is identical with
the result obtained by direct experiment.

From these facts, then, it appears that the hair salt of
the coal strata varies in its composition. But this deduc-
tion is what we should have been inclined to draw, from
the consideration of various analyses by different chemists,
of specimens of similar salts from other localities, which
affect the same form of crystallization, although consist-
ing of totally different constituents. Thus sulphate of
magnesia, sulphate of manganese, as well as sulphate of
alumina and iron are found, we have also seen in capillary
crystals.

Upon what circumstances this remarkable asbestus form
of soluble salt depends, it is not easy to determine, because
they are indifferently met with in various species of rocks.
This form, however, in insoluble minerals, as has been
observed, is connected with serpentine rocks.*

Thomson's Inorganic Chemistry, i. 161.

62 F. J. Kutzing on the [July

Article VIIL

Observations on the Formation and Changes of the inferior
orders of Plants. By F. J. Kutzing.*

The nature of the lowest species of plants is a subject of
interest. M. Kutzing, from many observations which he
has made upon them, has drawn some important results.
Distilled water remained stationary for six months, with-
out shewing any appearance of green matter on its surface.
Water which had been distilled over plants presented a
different aspect.

In some of them a mucus began to shew itself in the
course of eight days ; in rose water in about two weeks.
First the mucus is deposited, and the characteristic odour
of the water disappears. Hence, this mucilage would
appear to be formed at the expense of the essential oil.
No filaments or globules can be discovered at this stage ;
but if the water is less exposed to the direct influence of
the sun, they appear at first colourless in the mucous mass,
and then the different forms of Hygrocrocis and Leptomitus
shew themselves. This constitutes the second step ; the
light of the sun determining whether Protococcus or Hygro-
crocis shall be developed. The lowest state of these globules
is well exhibited in the genus established by Kutzing, of
Cryptococcus which is inferior to Protococcus ; for in the for-
mer the organic mucus is only observed in the form of minute
globules, while in the latter, they are larger and possess
colour with a more solid texture. The third step is the
formation of filaments, by the union or elongation of the
colourless globules, giving origin to Hygrocrocis or Lepto-
mitus. The L plumula is an advanced state of Cryptococcus.
The latter is formed in moist windows. Kutzing has ob-
served the formation of an Oscillatoria which he calls /ewes-
tralis, over a stratum of Cryptococcus, which previously
became a Palmella. If we term the transformation of
Cryptococcus into Hygrocrocis and Leptomitus a direct pro-
gressive step, we may call that of Cryptococcus into Palmella
and Protococcus, latterally progressive.

* Ann. des Scien. Nat. II. 129.

1835.] Formation and Changes of inferior Plants, 63

It is worthy of remark, that the Protococcus is often
found in dry places, for it seems that it never appears in
water except when the sun is shining on it, and the Hygro-
crocis and Leptomitus appear in the shade. It has been
observed that the algae (algues) are formed after the death
of the Infusorii, especially the Enchelys pulvisculus. When
the water in which this animal is found, is evaporated, the
latter contracts after death into globules. These possess at
first their transparency at the extremities, which correspond
to the head and tail ; but gradually they contract into ti ring
surrounded by other globules, and assume an appearance
resembling Protococcus; only it is mucilaginous when
united in large masses, and is therefore more like Palmella.

At this time an Oscillatoria begins to appear, which Kut-
zing terms hrevis. It is always the same plant. The author
confirms the accuracy of the observation of Treviranus
with regard to the motion of the sporules of algse. He ob-
served the motions of millions of globules while examining
the Draparnaldia plumosa in a glass of water. Under the
microscope he noticed, that as the green border (which was
formed on the second day after depositing the plant in
water), increased, the filaments of the Draparnaldia, lost
their green colour and became hyaline, and the globules
resembled then the Cymbella (Frustulia.) These move-
ments somewhat resemble those of pollen in spirit of wine,
camphor in water, &c., but they are of longer duration.
By keeping a Protococcus which was seated on sandstone
constantly wet, the globules became connected, filaments
were formed, and a conferva produced, which he calls
tenerrima{C MuralisSi^reng.) This plant is found in the
waters of reservoirs, and is transformed into an alga of a
superior order, the Inoderma, Kutzing observed the
Alysphceria Jiavo-virens to be produced from ih^ Protococcus
viridis, by the conversion of the globules into dichotomous
filaments.

He found likewise, that by examining the structure of the
Parmelia parietina, it is observed, that the globules of the
Protococcus viridis, which occurs on trees along with the
lichen, enter into its frond, and that the latter is the first state
of the lichen. Upon the upper part of trunks of trees, we
observe the Parmelia parietina. At the base we notice

64 * Analyses of Books. [July

filaments of Protonema, which are generally converted into
Orthotrichum, Hypnum and other mosses.

Kutzing has distinctly observed these threads of Proto-
nema formed by gl6bules of Protococcus. These globules
swell, being filled in the interior with a green liquid, and
are gradually expanded into filaments. It appears that the
formation of Alysphceria does not necessarily precede that
of the lichens, but that it is an independent structure.
Kutzing observed the Barhula muralis a moss, produced
from Protonema and also from a Protococcus. The genera
Zygnema and Mongeotia are generally found in shallow
water. When the water containing these plants is evapo-
rated, the Conferva quadrangula appears. From the Mon-
geotia genuflexa in this way proceeds the Riccia crystallina.

From his observations Kutzing infers : —

1. The formation of organic matter cannot take place,
except from elements of other organic principles already
dissolved.

2. Simple globules ( Cryptococcus, Palmella and Proto-
coccus)^ may produce different plants according to the
influence of light, air and temperature.

3. The superior algse are plants of very simple structure.

4. The same superior structure may be produced from
original structures altogether different. Thus, the Barhula
muralis, is formed from the Protonema which comes from
a Protococcus, and again proceeds from the remains of the
dried Palmella hotryoides, without passing through the
stage of Protonema.

Article IX.

ANALYSES OF BOOKS.

Introduction a Vetude de la Botanique ou Traite Eleinen-
taire de cette Science. Par Alphonse De Candolle, Pro-
fesseur a I'Academie de Geneve. Paris, 1835, 2 tomes.*

This work in two volumes, accompanied with plates, contains under
a modest title a clear and methodical exposition of all the divisions
of which the extensive science of botany now consists, but formerly
limited to the more or less exact description of a smaller number of
plants. These divisions are Organography, or the description of

• Bibliotlieque l^niverselle, January 1835.

1835.] De Candolles Introduction, ^c. Q6

the elementary and compound organs which enter into the structure
of vegetables, and by means of which they discharge their different
functions ; Phi/,siolo<i;t/, or the enumeration of the phenomena re-
lative to their nutrition and re-production ; Methodolot^yj or the
act of classifying vegetables in families, orders, and genera, accord-
ing to their affinities, and of describing these families, orders, genera
and species, in such a way as to render them readily recognizable ;
Botanical ^eos;raphy, or the actual distribution of vegetables in
families, genera and species over the different parts of the globe ;
Oryctology, or the situation and disposition in families, genera
and species of the fossil vegetables discovered in our time ; Medical
Botany, or view of the relations which exist between vegetables and
their different organizations ; Lastly, the history of the science, or
its successive developement from its origin down to this time.

Each of these primary divisions contains subdivisions of more or
less importance. Thus, under organography, the theory of union,
abortion and the metamorphoses of the organs is developed. Under
physiology the different products extracted from vegetables ; the dif-
ferent phenomena presented by a plant from its flowering to the
dissemination of its seed, the principles upon which the art of engraft-
ing ; the various duration of vegetables, and the deleterious influence
which mineral, animal, and vegetable poisons exercise upon them
are pointed out. Under methodology, after fully explaining nomen-
clature, botanical collections, and gardens, the different families into
which the vegetable kingdom (pointing out in each the authors and
the works to be consulted) are enumerated.

This work may therefore be considered the most complete treatise
which has appeared on the subject, and it is written with great pre-
cision and clearness. It exhibits a great extent of botanical know-
ledge, and is accommodated to the present state of the science, as
the author states the opinions brought forward in the most recent
European works of botany, and candidly adopts those which appear
to him of most weight.

In another point of view, this work will be found of great utility.
If an observing botanist in the course of his studies meets with a
subject which appears to him worthy of examination, and for the
elucidation of which he requires to consult books, he will find proper
directions for this purpose in the work of De Caridolle. If, for ex-
ample, he is forming a monography of a family, he finds the names
of the authors who have been previously engaged in the same task,
and the progress which they have made. But not only are former
discoveries well explained, but new views are developed. Thus, for
example, in his elementary theory, his father recommended, in order
to ascertain if a classification was really natural, the comparison of
the results of a classification deduced from the organs of re-produc-
tion, with that deduced from the organs of vegetation, as he con-
sidered that when these agreed, it might be inferred that the method
was in reality natural. J3ut INI. Alphonse De Candolle remarks,
that the elementary organs (cells and vessels) being the' common
basis of the organs of nutrition and re-production, cannot be exclu-
sively considered as belonging to either series, and proposes to con-
VOL. II. F

%

Analyses of Books. [July

sider separately under taxonomy, the elementary organs, viz. the
cells, vessels, the organs of vegetation or the roots, trunks and
-leaves, and the organs of re-production, or flowers, fruit, and seeds,
and to deduce the natural method in accordance with these three
classes of organs. He explains then witl^ great precision all that
concerns the subordinary parts of the organs of nutrition and re-pro-
duction ; he points out among vegetables the degrees of resemblance
or association, and among the natural groups, the affinities existing
among themselves and with other groups, and he finishes by com-
paring the systems of classification.

But the most curious and novel part of the work is that which
relates to botanical geography. The general laws of this distribu-
tion are, that vegetables increase in number and dimensions, in pro-
portion as we advance from the poles to the equator ; that the annual
species are more extended in the temperate zones and the woody
plants in the tropics ; that certain localities are affected exclusively
by certain families or tribes, or even by certain genera of these
families or tribes ; that in dividing the surface of the globe into forty-
five regions, bounded by mountains, seas, or deserts, we find each
region almost characterized by distinct families ; the dicotyledonous
plants being more numerous when the country is hotter, and the
monocotyledonous when the district is colder ; that islands have a
vegetation increasing in peculiarity as they are more isolated
and removed from continents. That consequently we may regard
these regions as so many centres from which have proceeded so
many vegetable creations of families, tribes, and peculiar genera.^

These families, tribes, genera, and species, are diff*erently mixed
by the effect of winds, rivers, and currents, and especially by birds
which have transported here and there, and particularly in the
neighbouring regions, seeds which at first belonged to one country
alone. Sometimes, however, these creations generally so distinct,
co-exist in distant localities, a fact, which cannot be explained by any
of these agencies. Thus the Primula farinosa and Poa alpina,
are found in the neighbourhood of the two poles at the Malouine
islands (Melvin,) and on mountains in Europe, and are not met
with in the intermediate countries.

Genera are rich in species in proportion to the heat of the country,
and these species are often divided into sections possessing peculiar
climates. Thus the Saxifraga, Anemones, and Rhododendrum,
* &c. of Europe, are diflTerent from those of the Himalaya mountains,
and our oaks are distinct from the species of North America. Some-
times also the same genus has species dispersed in different regions.
Thus the three species of Trollius inhabit respectively, Europe,
Asia, and America. The species have a distribution more or less
extensive, and this distribution possesses a centre or a point in which
they abound in greatest quantity, and from which they become
rarer and gradually disappear. An exception must of course be
made in favour of those cultivated by man, and those naturalized
around human habitations as Urtica urens, Chenopodia, &c.

The Amphigamous order, in the class Cri/ptogamia, which have
very obscure sexual organs, are not limited by botanical regions.

1835.] De Candolles Introduction, Sfc. 67

because their seeds or sporules are so minute that they are scarcely
visible, and might be easily carried over seas and mountains. Thus
the cold zones of the two hemispheres, where these plants predomi-
nate have many specie, in common, and M. De Candolle the father,
has sometimes remarked upon the trunks of trees in the promenade
of Quimper-Corentin, on the side exposed to the south-east wind,
two Jamaica lichens, Sticta crocata, and Physcia Jlavescens.

The book which treats of vegetable fossils is filled with curious
observations, extracted principally from the Prodromus of M.
Adolphe Brongniart, which appeared in 1818. This author divides
the primitive formations, or those which contain no trace of orga-
nized beings into four great categories, each of great length, and
the secondary with the tertiary into four formations divided into
fourteen distinct epochs. In the first of these formations which
extends from the first transition beds to the end of the coal deposit,
there exists a great proportion of cryptogamic plants, especially
arborescent Fuel, Equisetacece, and Lycopodiaceae, of which we
can scarce find any analogies at the present time in the warmest
climates.

The second formation, which is least known, possesses rather more
phanerogamous than cryptogamous plants ; in both, different from
those of the first period. The third contains a very great proportion
of Cy cades, a family allied to cryptogamia, but which does not exist
at the present day. Lastly, comes the most recent epoch in which
the phanerogamous plants predominate, especially the dicotyledo-
nous. The results which these facts ascertained in our time pre-
sent, are numerous, and very remarkable. We prominently observe
that the vegetables contemporaneous with the first formation, are
very different from those which exist at present ; and that those
which have succeeded them in the two other periods, have no more
resemblance to the first than to each other ; so that there has been
a successive creation of families, genera and species up to the fourth
and last period, which presents vegetables analogous to those now
existing, and being formed of a greater number of organs than
the preceding, are consequently more perfect. There is here a
striking correspondence between the two organic kingdoms ; for ver-
tibrated animals, of which man is chief, only appear in the last
formation; and in the two kingdoms, we find in our northern
climates beings, which could not be propagated at present, because
the temperature appears to have been formerly higher than it is at
present.

Several interesting points have been omitted by the author, such
as the source of our different species of cultivated grain, which we no
longer find in a wild state, but which have not been produced by
cultivation, as is proved by the fact, of wheat having been found in
Egyptian mummies 3000 years old, * in almost a perfect state of
preservation, and equal in size to that cultivated among us.

The most imperfect part of the work is that which treats of the
superior phenomena, which escape our physical explications, and

* Records of General Science,.!. 446.

f2

68 Analyses of Boohs. [July

which depend on unknown powers, which we are in the habit of
designating by the obscure name of vital powers, because they are
connected with the preservation and permanence of the species.
These mysterious agents surround, as it were, the' cradle of the
young plant, which they accompany in its flowering and fecundation,
and during its rise to maturity and its dissemination.

Their influence is particularly conspicuous in the precautions
which are observed during germination, in the motions which the
peduncles execute, in exposing sometimes the flowers to the action of
fight ; at others, in withdrawing the seed from the injurious effects
of moisture. The explanation of all these phenomena, and many
others, will, however attract, the attention of botanists, and, sooner or
later, we may expect them to be elucidated.

II. — Memoir on the Fresh Water Formation of Burdiehouse,

6rc, By Samuel Hibbert, M.D., F.R.S.E.

(From the Edinburgh Trans, vol. xiii.J

This constitutes an excellent geological monograph ; the nature of
a novel limestone and its fossil contents being well developed, in so
far as they have been hitherto laid open to inspection. In the first
volume of this Journal, a paper, by Dr. Scouler, is inserted, containing
a description of two new species of Entomostraca, which the able
author had discovered in a limestone connected with the coal beds.
A comparison is there instituted between the vegetable and animal
inhabitants of existing pools and lakes and those of the coal formation.
The strata described in the memoir of Dr. Hibbert, appear to be
identical with that in which the new animals of Dr. Scouler were
imbedded, and also with the Bathgate rock from which the latter
geologist derived his Eidothea, the Euri/pterus Scouleri of Dr.
Hibbert, so that the accuracy of Dr. Scouler's opinion is confirmed,
at least in reference to this element of the carboniferous series.

In our notice of this memoir, the new facts brought forward by
the author will be briefly alluded to, nearly in the order which he
adopts.

1. Character of the Limestone. — Colour from a blueish or
blackish gray to olive brown or purple. Fracture sometimes slaty,
sometimes conchoidal. It occurs in the quarry in the form of regular
inclined strata, dipping at an angle of 23° or 25°. The joint thick-
ness of the mass amounts to 27 feet ; it is referred to the lower
beds of the coal series ; under it occur sandstone, shale, and a very
thin seam of coal ; immediately above it lies a thick mass of a similar
rock to that below it, containing, however, ironstone. Next comes
a thin bed of limestone with marine shells, and, lastly, the coal
measures of Loanhead, and at each extremity of the series described,
there is a fault.

2. Fossil Flora.-^The Sphenopteris ajffinis occurs very abun-
dantly. The appearance of this fern is interesting, because it is
found in the old red sandstone near Cockburnspath, a rock which can

1835.] Dr. Hihhert on a Fresh Water Formation^ ^c, 69

be distinctly traced running into the greywacke in the immediate
neighbourhood of Longformacus, and therefore strengthens the idea
of the great age of this limestone.* Besides this fern there are
Sphenopteris bifida^ Sphenopteris linearis, Lepidodendron sela-
gtnoides, L. Obovaium, L, Steinbergii, Lepidophijllum inter-
medium, Cyperites bicarinata, Lepidostrobus variabilis, L.
ornatus, Cardiacarpon acutum, Sti^maria ficoides, together
with species of Sigillaria, Equisetum, Calamites, and Cyclopteris,
which it is to be regretted had not been referred to some fossil
botanist, previous to the publication of this memoir.

3. The microscopic animals found in the Burdiehouse lime-
stone, possess a structure in common with that of well know EntomoS'
traca. These are the Cypris faba, a new species which Dr.
Hibbert has termed Cypris Scoto Burdigalemis, and two others,
one of which he refers to a new genus Daphnoidea, and the remain-
ing to Planorbis, or perhaps a new genus.

The shells of this description occur in very great abundance,
proving the extent to which this primeval lake had been supplied
with animal life, and the gradual and quiet nature of the calcareous
deposit.

4. Fossil Fish. — The discoveries made among this class of fossils,
develope some of the most important facts which have been brought
to light of late years, not only in geology but likewise in comparative
anatomy, and to M. Agassiz, Professor of Natural History at Neu-
chatel, the credit is entirely due.

Those fish which have been examined are referable to two orders
in the system of Agassiz.

1. The Placoidean order distinguished by the irregularity in the
solid parts of their integuments, which consist of materials of enamel
often considerable or reduced to little points. The fish discovered at
Burdiehouse belonging to this order has been termed by Agassiz
Gyracanthus formosus, which approaches the modern Cestracion.

2. The Ganoidian order distinguished by its enamelled angular
scales, includes the Palceoniscus Robisoni, Amblyptems, and a
new fish termed Eurynotus crenatus. The family of Lepedoids,
which is characterized by having teeth disposed like a brush in several
rows, or one single row of small obtuse teeth, and the Pygopterus
Bucklandi among the family of sauroids. But the most extraordi-
nary fish belonging to this family is that termed by Agassiz the
Megalichthys Hibberti, approaching to the Lepidosteus gavial, so
called from its resemblance to the crocodile of the Ganges, yet con-
stituting the type of a new genus. It is characterized by the alter-
nation of large and small teeth, which have less plicse at their base
with a smooth surface. The scales exhibit a coating of enamel of a
nut brown colour, with frequently a brilliant lustre, an angular
shape, and a punctured surface resembling that of the crocodile.
Chemical analysis of the scales confirms the supposed analogy be-
tween the recent Lepedosteus and Megalichthy. M. Agassiz did
not content himself with an -examination merely of the Burdiehouse

* Masaz. of Nat. Hist. v. 644.

70 Analyses of Books. [July

specimen, but he visited numerous museums and observed similar
fish. The remains of another species placed in his hands from
Greenside, near Glasgow, he describes under Megalichthys falcatus.
It is reasonable to suppose, as Dr. Hibbert suggests, that many-
remains which have been considered those of saurian reptiles, may
belong, to this genus which possesses the mixed organization of fish
and reptile. He instances what he considers several examples of this
kind of mistake. By the discovery of this genus, much light has been
thrown upon the nature of the localities in which the older carbonifer-
ous rocks were deposited; for we have only to study the anatomy and
habits of the recent Lepidosteus, a sauroid fish which dwells among
the lakes and rivers of the most thermal regions of America, in order
to be convinced that these fossil and recent fish, so analogous in
every respect, must have been placed in the same circumstances.
Copr elites occur at Burdiehouse abundantly, sometimes attaining to
a great size, and occasionally being diffused over a surface of lime-
stone to the extent of nearly a foot. These foecal remains are of a
pale yellow colour, and consist, according to Mr. Connell, of phos-
phate of lime, with some fluate of lime 85*08 ; carbonate of lime
10*78 ; silica 39 ; potash and soda -59 ; bituminous matter 3- 95 ;
with a trace of phosphate of magnesia and animal matter.

The second portion of the memoir treats of the Burdiehouse strata,
with reference to their geological position, and is full of interesting
matter ; but to do justice to the details it would be necessary to read
them. It is proper to observe, however, that the author draws from
his researches the following inference in favour of the fresh water
origin of the strata.

1. '' That it is by the presence or absence of acknowledged pelagic
moUusca, corallines, &c. that indications are afforded of the great
difference between fresh water and marine deposits.

2. *^ That if along with marine moUusca or corrallines, we find
the plants of coal-fields in a quantity comparatively small, an
estuarian limestone may be inferred.

3. " That if marine mollusca or corallines should be entirely
absent in a limestone, and if plants should be abundantly found in
it, an indication would be afforded of a calcareous deposit which took
place amidst the fresh- water rivers or lakes of primeval marshes ;
which indication would be still more favoured, if we should find in
addition recognised genera of fresh- water shells, the entomostraca of
stagnant marshes, or the fish incidental to coal-fields."

He anticipates the objection of the possibility that molluscous
animals may yet be discovered, by observing, that they cannot occur
in any great abundance, and that their presence would indicate that
the fresh water lake had been merely connected with an ancient sea.

The mode in which the formation was deposited, he supposes to
have been as follows : —

Springs charged with carbonate of lime and issuing from deep
crevices, had mingled their mineral contents with some sluggish river
which flowed over a marshy tract principally overrun by the creep-
ing stems of Lycopodiaceae, and a dense overgrowth of ferns, con-
taining conspicuously Sphenopteris ajjlnis. Hence, the gradual

1835.] Analyses of Books. 71

deposition of calcareous matter around these vegetables, had preserved
the plants in a perfect state, unaffected by the violence of currents or
by any of the atmospheric commotions, which a later or less heated
condition of the globe has invoked.

Dr. Hibbert in following out his subject, has identified the fresh
water limestone of Burdiehouse, with similar deposits at East and
Mid Calder, Burntisland, and Kirkton near Bathgate. We have
little doubt that discoveries of formations analogous in their nature
will soon be multiplied. We have before us a tooth transmitted by
Dr. Johnston of Berwick, from the Rev. Mr. Knight of Ford, which
was found in a sandstone belonging to the coal measures in the
north of Northumberland, and appears to approach some of those
figured by Dr. Hibbert ; but is considered by a distinguished com-
parative anatomist as that of a fish.

It would be improper to close this brief notice without an expres-
sion of admiration, for the enthusiasm exhibited by the author in the
prosecution of his researches in the new field which he has opened
to geologists ; his exertions I in preserving the fossil remains, and
the candour with which he has acknowledged the observations and
assistance of his fellow-labourers.

The memoir concludes with a chemical analysis by Mr. Connell,
of the fossil remains and lithographic illustrations which are very
important additions.

Article XI.

SCIENTIFIC INTELLIGENCE.

I. — Royal Institution. Dt. Faraday on Sound. — \bth May.
Dr. Faraday illustrated the recent discoveries of Savart upon sound,
which although well known are still of a highly important nature.
They establish the fact, that low notes when formed by drawing a bow
across the edge of a plate of glass strewed over with sand, exhibit
the points of quiescence in the regular form of a right angle ; while
in membranes, irregular figures are produced; the sand being arranged
along the quiescent parts. When lycopodium is used, however, it
is thrown upon the points of vibration. The effect of vibrating
bodies, when allowed to communicate their action to membranes, is
interesting, because it illustrates the nature of the ear. An experi-
ment, devised by Mr. Wheatstone, exhibits the connexion of the
bones of the ear with the membrana tympani. A membrane is
stretched over a basin, and a piece of flat wood communicates with
the membranes, projecting over the rim of the basin, externally to a
considerably extent. The wood and membrane are strewed over
with sand, and a bell-glass which has been vibrated, is brought into
the vicinity of the membrane. The sand immediately arranges itself
in a straight line along the w^ood ; but the same result does not en-
sue, when the vibration is communicated through the wood.

The effect which the bones of the ear have in varying the tension
of the membrana tympani, was illustrated by means of a membrane

72 Scientific InteUigence. [July

stretched over the extremity of a conical vessel, with a bit of wood
so adjusted, as to admit of being pressed at pleasure to the membrane.
Dr. Faraday concluded by stating, that the phenomena of electricity
are similar to vibration, and that they appear, (though he spoke
diffidently) to him to be closely analogous, and that the phenomena
of light are best explained on the same principles. Chemistry, he
observed, was nothing but electricity. Hence, all philosophers are
now looking out for a general principle, much higher than gravitation.

22nc^ May. — Mr. Brockden gave an account of the devastation
occasioned by the great storm among the Alps, in August, 1834,
when property to the amount of many millions of florins was utterly
destroyed. The facts which he brought forward were derived from
travellers.

'2Qth May. — Mr. Davidson on the ancient Egyptian City of
Thebes.

Sth June. — Mr. Cooper on Engraving and Marble Sculpture.

11.— Diseases of the larch. ^

According to Mr. Stephens of Edinburgh, who has addressed a
letter to De CandoUe upon the subject, the larch ( Lar'ix Europcea),
is subject in Great Britain to two diseases. The first disease consists
in the decay of the heart of the wood. It occurs not only in wet
situations, but also in dry places, as in Nottinghamshire, where
immense losses have been sustained. It has only manifested a slight
appearance at Dunkeld, and is most prevalent in England. The
larch has been found not to thrive, where Scotch fir {Pinus St/l-
vest7'is) has previously existed ; but this is not the cause of the dis-
ease. Another disease to which it is subject, is a blister, which
forms about 2 feet above the ground. These blisters are produced
on two sides of the tree alternately, until they reach the top, when
the tree dies from above downwards as it were. Sometimes the
blister surrounds a branch, which breaks off in the course of time.
This accident is frequently ascribed to the weight of snow. The
range of this disease is at present bounded by the county of Forfar,
and the south of the Grampians. It attacks entire plantations, but
rarely trees above 25 years of age, and is most destructive in poor
soils, or on hard formations, as clinkstone.

None of the Dunkeld trees, at an elevation of 1000 feet have
been affected.

De'Candolle states, that on the Alps, the larch is free from any
disease, save the occasional loss of its leaves by the attacks of a cater-
pillar, and a resinous blister or cancer, which however, produce no
injurious effect upon the tree. It grows extremely well at Moritz-
burg, near Dresden, in a moist sandy soil, 238 feet above the sea.
He proposes for this country the following recommendations :

1. That the higher parts of the country are best suited for its

* Bibliotheque Universelle, February, 1835.

1835.] Scientific Intelligence. 73

growth, provided that the ground be not too dry, nor hard, nor
marshy.

2. That the sides of the hills are better suited for it than the
summits, and if the summits are marshy, the inferior parts of the
mountains will be proper for it.

3. It is remarked on the Alps, that the larch succeeds better in a
northern than in a southern exposure. The difference is sometimes
so striking, that in vallies running from east to west, it is not un-
common to see the side exposed to the north covered with larches,
and that exposed to the south, with scarce a tree. This may be
ascribed to the irregularity of the spring, but will not apply to this
country.

4. The plantations of larch in this country are too thick, the
trees being generally planted at a distance of 3 or 4 feet. De CandoUe
considers that the young trees ought to be planted at a distance of
10 feet, and if planted closer, they should be gradually thinned for
20 years.

He recommends likewise, that for security, new seed should be
brought from the Valais, where the cones are dried by the heat of
the sun, and not from the Tyrol, where fire is employed for this
purpose.

M. Em Thomas sells them at the rate of 2i francs (2s. Id.) the
half Kilogramme (1 3 lb. troy). M. Thomas advises that the trees
should be always transplanted in autumn and not in spring.

III. — Arsenic in English Sulphuric Acid.

VoGEL of Miinchen, infers from his experiments on sulphuric acid.

1 . That the IS^ordhausen acid, prepared from the sulphate of iron
contains no arsenic ; the precipitate with sulphuretted hydrogen being
pure sulphur.

2. Concentrated English sulphuric acid prepared in leaden cham-
bers contains arsenic, and the precipitate produced in it by a current
of sulphuretted hydrogen, consists of sulphur and orpiment.

3. No precipitate of sulphur takes place, in consequence of a
current of sulphuretted hydrogen being passed through English
sulphuric acid, diluted with from four to six parts of water ; the
precipitate consisting of an orange yellow powder or orpiment.

4. Rectified English sulphuric acid contains no arsenic ; this sub-
stance remaining in the residue. The rectified acid diluted with water
is not rendered muddy by sulphuretted hydrogen. The German
sulphuric acid diluted with water, becomes white when the latter gas
is passed through it, as it always contains sulphurous acid.

5. The arsenic always exists in sulphuric in the form of arsenious
acid, never as arsenic acid.

6. Concentrated boiling sulphuric acid can dissolve one»third of its
weight of arsenious acid, of which the greater part separates on
cooling. The arsenious acid may be precipitated in a great measure
from the concentrated sulphuric acid when cooled, by absolute
alcohol, although it is somewhat soluble in alcohol.

74 Scientific Intelligence, [July

7. Lastly, it is absolutely necessary that in all preparations to be
used internally, rectified, or at least, German sulphuric acid should
be employed.*

IV. — American Patents.

Nearly one-third of the journal of the Franklin Institute is occu-
pied monthly, with a list of American patents and remarks upon them
by the editor. The number of patents taken out in June 1834,
amounted to fifty-six, for July forty-eight, and for August fifty- six.
This multiplicity of claims to discovery, no doubt, originates from
the small expense incurred in obtaining a patent.

Accordingly we find that two or three patents infringe on each
other ; the slightest deviation from a previous specification being suffi-
cient to produce a new patent. In August, a patent was taken out
for ajly-drtver, or instrument for driving away flies, which re-
sembled two previously patented machines of the same nature.

A patent for a saw-knife, specifies that you are to " take a
common knife and cut teeth in the back of it, and you have the
patent saw knife."

A steam bug destroyer, patented in July, is exactly similar to
three others which had previously obtained patents, and " what is
somewhat curious, all of them are similar to such as had been pre-
viously described in the English journals."

In the account of a new patent for medicated liquid magnesia,
we learn, that Mr. John Cullen of Philadelphia, obtained a patent
16 years ago for liquid magnesia, which was formed by forcing car-
bonic acid into water, containing magnesia suspended in it, until the
latter was " dissolved. This is similar to the preparation lately
recommended by Dr. Murray of Belfast.

V. — New Method of Drying Plants.
Dr. Hunefeld recommends a new method of drying plants, by
covering tliem first with the powder of lycopodium, and then placing
them in a vessel containing chloride of calcium. By this method
the colour and flexibility are preserved. On the 29th of July, 1831,
the thermometer being at 53^°, Dr. Goppert of Breslaw, placed in
a 24 ounce glass two leaves of the hyacinth, and a specimen of the
Fumaria officinalis, with two ounces of muriate of lime, in such a
manner that the plants were not in contact with the salt. On the
following day the leaves began to dry, and on the 3d of August,
although not dead, the hyacinth leaves were capable of being reduced
to a fine powder. Even fleshy plants as the Sedum rupestre are
so much dried in seven days, that they may be pulverized. The
use of the lycopodium powder is to prevent the sap from escaping. —
{Brande's Pharm. Zeit. 5. 1835, 71).

VI. — Flora of the Arkansas.
Mb. Nuttall in the fifth volume of the Transactions of the Ameri-
can Philosophical Society, has published a list of the plants of this

* Erdmann and Schweigger's Journal fur Praktische Chimie, iv. Tob.

1835.] Scientific Iiitelliyence. fSf

distant territory so far as they have heen observed. Among them
there are a very considerable number which are natives of Great
Britain, viz. ;

Polypodium vulgare, Pteris aquilina Equisetum hyemale-
Chara vulgaris, Lemna mi/nor and polyrhizttj Callitriche vema,
Myriophyilum spicatum^ Potamog:eton nutans and heterophyl-
lum, Typha latifolia, Carex flava, Scirpus lacustrisj Eieocharis
palustris, Rhyncospora alba, Schoeus setaceus, A^^rostis vul-
garias, Alopecurus geniculatuSj Poa pratensis, P. annua and
P, nemoralifs, Juncus effusus, Luzula campestris, Alisma
plantago, Polygonum avirculare, Rumex acetosella, Fagus syl-
vatica, Urtica urens, Humulus lupulus, Euphorbia peploides,
Plantago major j Samolus valerandi (near the town of Arkansas)
Utricularia vulgaris Lycopus vulgaris, Nepeta cataria, Gle-
choma hederacea, Marrubium vulgare, Clinopodium vulgare,
Origanum vulgare. Prunella vulgaris, Cynoglossum officinale,
Lithospermum arvense, Solanum nigrum, Verbascum thapsus.
Convolvulus arvensis.

VII.— jP. p. N. Gilletde Laumont.

Francois Pierre Nicolas Gillet db Laumont, was born at
Paris, 28th May, 1747^ and was the son of Pierre Gillet, a cele-
brated advocate. Gillet de Laumont at first applied himself to the
study of law, and was made an advocate on the 8th August, 1768 ;
but on the formation of a new Parliament he left the profession of
the law, and underwent the mathematical examinations necessary
for admission into the military school. In 1772, he entered into
the royal grenadiers and distinguished himself so highly, that in less
than five months he rose from the rank of ensign to that of captain-
commandant. His passion for science was however so great, that in
1784, he abandoned the military career, and applied himself to the
study of mineralogy under Sage, Bournon, Manon, Daubenton,
Rome Delille, De la Meltiene, Hauy and Saussure. Previous to
this he had discovered the crystalline sandstone, in the forest of
Fontainebleau, and the true nature of the lignites in the clay of
the Paris bason. The same year he was nominated inspector of
mines, and surveyed the mines of Brittany and the Pyrenees. It
was on this occasion that he discovered in the mines of Huelgoat,
the green phosphate of lead and the beautiful efflorescent zeolite,
termed laumonite by Haiiy. In 1787 he surveyed the strata in the
neighbourhood of Paris, and determined the nature of the wood coal
of Verberie, Soissons, &c. In 1789 he presented to government
a memoir on the min^s of France. In 1792 he added to his own
collection of minerals, the magnificent cabinet of Rome Delille. In
1794 he organized along with Lefeveres and D'Hellencourt, Le
Lievre, and Fourcroy, the new school of mines. In 1801 he pre-
sented to the Royal Society of Agriculture, statistical tables of the
minerals of the department of Seine, and the same year read to the
institute a paper on the conversion of muriate of silver into native
silver by the use of zinc or iron. He describes also the tin mines

76- Scientific InteUigcnce. [July

of Vaury in Haute- Vienne. He was besides author of numerous
papers in different periodicals. In ] 8 13 he was decorated by Napo-
leon with the Order of the Reunion. In 1815 Louis XVIII. named
him a Knight of the Legion of Honour, and in 1819 he was
admitted into the Order of St. Michael. His library, manuscripts,
and rich collection, were open to all. He was a good father and an
excellent husband. Let his memory be cherished by men of science.

VIII. — Severity of last Winter in America.

The coldest weather on record in Albany, previous to the present
year, was January 21, 1827, when the thermometer stood at — 23".
On the 4th January, 1835, the temperature was — 32°. At Hartford,
on the same day, the thermometer stood at — 24" 8. At'New Haven,
(Connecticut) — 23°, at seven o'clock in the morning. At Saco,
(Maine) •— 27'' -4. At Goshen, (New Jersey) —32°. At Montreal,
— 35 . Lebanon (New York) — 40". Montpelier, (Vermont) — 40 '.
It is worthy of remark, that the greatest cold was experienced in the
interior, the thermometer being highest at the sea-coast. At Dart-
mouth the thermometer was at — 32° at sun-rise, and the barometer
29*76 inches. A brilliant aurora was seen. A great snow storm
reached Dartmouth on the 30th December, 1834, having com-
menced 24 hours earlier at Washington. The depth of snow was
20 inches at Baltimore, 15 at Boston, and 10 at Dartmouth. — At
New Haven on the 2nd January, 17^7^ the temperature was — 26^^.
{Sillimaris American Journal, xxviii. 177«)

IX. — New Cetaceous Animal.

D'Orbigny, in his Travels in South America, discovered a new
genus of cetaceous animals, in the rivers of Boil via, especially those
of Moxos, which run into Mamore, and thence into the Amazon at
Santa Cruz, at least 700 leagues from the sea. It differs essentially
from the dolphin or sousou of the Ganges, although it possesses the
characters of a dolphin. He terms it Inia Boliviensis. Inia is the
Indian name of the fish.

The specimen examined was a female. It was 2 met. 4 cent, in
length (8-14 feet).

Dorsal circumference 1 met. 4 cent. (4*85 feet).

Above, the body was pale-blue, passing into red below! The tail
and fins were blue ; but these vary considerably, for some speci-
mens are reddish. Those which inhabit the great rivers are pale,
while those which enter the great lakes which communicate with
the rivers during the rains, are almost black, and do not lose their
colour for a long time after their re-entry into the rivers.

The body is thick and short when compared with common
dolphins. The snout is very slender, almost cylindrical, and obtuse
at the extremity. The mouth terminates a little below the eye,
and forms a linear opening, only arched at the posterior part. The
nasal canal is so oblique that its orifice is placed almost above the

1835.] Scientific Intelligence. 11

swimming paws. Behind the eye, is the meatus auditorius extemus.
The anterior fins are large and obtuse at their extremity. The
dorsal one is placed at about a third from the extremity of the tail.
The posterior part of the body is compressed. The tail is large and
divided in the middle. The cranium is depressed. The snout is
long and supplied with teeth throughout its whole length, and has
from 130 to 134 teeth. The vulva of the specimen examined was
much swelled. The mammae, situated on the sides of the vulva,
were filled with milk which was easily pressed out. It appears that
the males attain a greater length than the females, some of the for-
mer reaching a length of 4 metres (13*12 feet). This species was
found in all the rivers in the province of Moxos. It reaches the
bottom of the C'ordilleras and never appears to visit the ocean, be-
cause it is so slow in swimming, that it could not possibly pass the 19
cascades of the river Madeiras, which exist in 9" and 10° S. L. The
Brazilian merchants who have travelled from Mato-grossa to Para,
state that these dolphins are found only above the falls, that is to say,
in the numerous rivers comprised between 10° and 17° S. L,

When not alarmed, these animals come quietly and much more
frequently, than the marine species to breathe at the surface of the
water, but when frightened they increase their speed, which is never
so rapid as that of the sea species. They generally swim in threes
or in pairs. Their sense of hearing seems very acute. They prey
upon the smaller fish, and frequently come to the surface to devour
their victims, which the sea dolphins never do. The Brazilians call
them Bote, the Spaniards Bufeo, the Guayaros Inia, the Chapa-
curas Sisi, the Baures Thui, the Moxos Indians A'ico^ the Itona-
mas Puchca, the Cayuvava Potohi. — ( Nouv, Ann. dm Museum.
iii. 28.)

X. — Combinations of Iodine with Paladium and Iridium.

The affinity of palladium for iodine is greater than that of platinum
for the same substance; for whenever the polished surface of the
palladium is brought in contact with the vapour of iodine at common
temperatures, or with the alcoholic solution of iodine it becomes
brown, which disappears by the action of ammonia or by the appli-
cation of heat. This affords an easy method of distinguishing the
two metals ; for no effi^ct is produced on platinum at a common
temperature.

The best mode of preparing the iodide of palladium is to mix a
solution of the iodide of potassium with the salts of palladium,
especially the chloride of that metal. A black flocky precipitate is
immediately produced. When collected on a filter and washed with
boiling water it presents the appearance of a black gelatinous mass,
which in drying passes through a series of changes like alumina.
When fully dry it has a resinous fracture, and is easily reduced to
powder between the fingers. In this state it is a hydrate, but it
readily loses its water by being placed in a dry vacuum for twenty-
four hours.

78 Scientific Intelligence. [July

It was found to consist of

Dry iodide . . . 94*95
Water 5*05

10000
It is insoluble in water, alcohol and ether.

It is not decomposed when heated to the boiling point in a con-
centrated sulphuric acid bath. A little above the boiling point of
mercury ((J68°), it parts with a portion of its iodine. It con-
sists of

Iodine 70 60

Palladium . . . 29-40

100-00

Hence it is obviously a simple iodide.

When hydriodic acid is poured upon the iodide of palladium no
action takes place, which affords a distinction between the iodide of
platinum and palladium, for the former produces a soluble combina-
tion with this acid.

The iodide of palladium, newly precipitated, when mixed with a
solution of iodide of potassium, forms a dark wine-coloured solution,
which contains a double iodide, and is not altered by the air or heat.
When evaporated, grayish black cubical crystals are obtained, which
are a double iodide of palladium and potassium.

The hydrous iodide of palladium combines with ammonia when
digested in caustic ammonia. By evaporation, orange crystals of
ammonia and iodide of palladium are procured.

Caustic potash precipitates the oxide of palladium when boiled
with iodide of palladium. Bi-iodide of iridium is prepared by
mixing a solution of iodide of potassium with a solution of the
bi-chloride of iridium, adding an excess of muriatic acid, and bring-
ing the liquid to a boiling temperature. A black powder precipi-
tates, which is the bi-iodide of iridium. It is insoluble in water
and acids. It decomposes at nearly the same temperature as the
bi-iodide of platinum, leaving metallic iridium. — {Lassaigne,
Journ, de Chim. Medic, i. 57.)

XI . — Volvox glohator (of Muller).

This is a little insect which is constantly revolving, and contains
other globules endued with motion which are independent of the
animal. It lives in still waters among confervae, and is of a beauti-
ful gray colour. Braconnot {Ann. de Chim. Ivii. 440.) collected a
number of these insects in the month of November. They formed a
gelatinous green mass. Hot alcohol became of an emerald green colour;
the animals became white. The residue and the solution when
evaporated formed a soft deep green fatty matter, which was reddened
by nitric acid, and was not dissolved in potash. It was identical with
vegetable chlorophylle. This matter gave up to water a little chlo-
ride of potassium. The matter which was not dissolved by the
alcohol was treated with boiling water. A little mucilaginous
matter was taken up.

1835.] Scientific Jntelligence. 79

The residue furnished by distillation much vegetable oil and some
ammonia. Muriatic acid dissolved from the product some phosphate
of lime, but water with a little potash dissolved it completely, pro-
ducing a thick mucilaginous liquid in which acids formed a coagulum.
The mucus matter taken up by the boiling,water was yellow and
semi-transparent. Nitrate of lead and sulpnate of iron, nitrate of
copper, lime water, barytes water, formed gelatinous precipitates
with it. Tannin rendered it opaline. Iodine had no effect. All
these properties are exactly similar to thosp which have been recog-
nised as characteristic of the mucilage of the Nostoc commune a
species of Alga common in this country. From which it appears,
that this plant holds an intermediate place between animals and
vegetables. The volvox then consists of,

1. A peculiar matter forming the greater portion of the animal.
2. Chlorophylle. 3. Mucilage identical with that of Nostoc com-
mune. Animal matter soluble in alcohol. 5. Chloride of potassium.
6. Phosphate of lime. 7« A combustible acid united to potash.

XII. — Capnomore,

Capnomore has been so termed by Reichenbach, because it is met
with in the smoke of organic bodies decomposed by fire. When pure
it is a transparent colourless liquid, possessing the smell of rum or
punch with a very agreeable taste. Specific gravity 0*9775 at 68 F.
It boils at ^Q^"" under a pressure of 28*25 inches. It does not con-
geal at — 5*8°. It evaporates without leaving any residue, it is a
non-conductor of electricity. , With the vegetable bases it acts as an
acid, and with sulphuric acid and the salts as a base. It does not
appear to unite with other bases, for a combination seems to be
produced ; it is decomposed by water. Capnomore is distinguished
from creosote and picamare by its taste, its insolubility in the
alkalies and acetic acid, and by the facility with which it dissolves
elastic gum. It differs from eupion by its specific gravity, and
boiling point, by the soot which it produces when burning, by its
solubility in sulphuric acid, its decomposition by nitric acid, and its
solubility in carbazotic acid, and the vegetable bases. (Journ.de
Chim. Medic, i. 195).

XIII. — Iron works in the Uralian District.

In this district there are nine iron works, of which, the oldest,
Nischney Taguilsk, was built in the year 1702, by Demidowitsch
Demidoff. It was so improved by Nicholas Demidoff that it pro-
duced annually five millions of roubles (of 833,333 6s. 8d.) Iron
and copper are smelted, gold and platinum are washed, and lead full
of silver and diamonds are obtained. The gold brings about
1,800,000 paper roubles, the platinum 1,152,000 roubles. After
paying expenses, the product of the iron, gold, and platinum,
amounts to from 2,600,000 to 3,000,000 roubles (£433,333 or
£500,000).

To the north of Taguilsk lies the iron work of Kuschva, on the
mountain Blagodat. The vein consists of magnetic iron ore. —
(Brande's Pharm. Zeit. 1835, 8).

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RECORDS

OF

GENERAL SCIENCE

AUGUST, 1835.

Article I.

Biographical Account of Baron Dupuytren.
(With a Portrait).

The advocates of public Concours may fairly boast, that
among other great men, it produced a Dupuytren. Without
this Institution, indeed, we do not see how such men can
be brought into their proper sphere of activity, at that fit
age, when the limbs are sure and nimble and the organs of
vision most perfect.

Whilst the Concours is the only efficient mode of testing
a professional man's ability, it becomes, at once, the most
powerful and most legitimate incentive to exertion, because
it ensures to him a fair appreciation and just reward,
according to his real merit. Without it, how could Dupuy-
tren have become Prosecteur to the Ecole de Santt at the age
of eighteen ? At this early period of life, he thus learned, that
he belonged to a country, where, whatever services he could
render to science and humanity, would be fairly weighed
with those of his competitors; and thus stimulated to
labour and exertion, he rose through the same honourable
means to be Chef des Travaux Anatomiques at the age of
twenty-four ; Second Surgeon to the Hotel Dieu at twenty-
six ; and at thirty-three, ascended the chair of Sabatier, as
Professor of Operative Surgery to the School of Medicine !
Nor can it be said that the Concours opens too easy a path to

VOL II. G

\

82 Biographical Account of [Aug.

eminence, and that, after such success, a man rests satisfied
and relaxes to ease and inertia. On the contrary, by Con-
cours, rivals are constantly rising up, closing upon you,
treading at your heels ; and, unless you go on, will not fail
to take your place. Dupuytren felt this ; and never did any
man go through a more brilliant series of labours to sustain
his reputation. He was indefatigable beyond example. For
twelve years he was at the hospital, morning and evening,
at 6 o'clock ; and, well or ill, was not known to be absent
onc« during that long period, at the Hotel Dieu! Each
morning, Sunday only excepted, he attended to 300 patients,
delivered a clinical lecture, performed several operations,
gave advice to some hundreds of out patients, and then
walked home to breakfast at half-past 10 o'clock!

After this, he saw his private patients, attended to the
examinations of students at the school of medicine, per-
formed his private operations ; and, at 6 in the evening,
again went round the wards of the hospital. Nothing less
than the discipline ofConcours could have trained a man to
the performance of such arduous duties, such tremendous
labour.*

William Dupuytren, one of the most distinguished sur-
geons of modern times, was born at Pierre Buffiere, on the
6th October, 1777. When three years of age a strange
event happened to him. He was a beautiful child, and was
playing in one of the streets of his native city, when a lady
who was travelling, and whose circumstances rendered it
advantageous that she should have a son, even at a great
price, happened to pass by that way. She was captivated
with the boy, and carried him off towards Toulouse. While
congratulating herself upon the possession of such a hand-
some child, his father succeeded in overtaking her, and
made her restore his son.

His appearance gained for him the regard of a cavalry

* For these introductory observations, as well as for the interesting remarks
embodied in many of the notes attached to this memoir, I am indebted to my able
friend and colleague Mr. King, who possessed ample opportunities of studying
the character of this distinguislied surgeon. The facts in the text are derived from
the " Essai Historique sur Dupuytren. Par Vidal, (de Cassis), Professeur
agreg6 a la faculty de medicine de Paris," &c. 8vo. 1835., to which are appended
the eulogies pronounced upon the deceased by Orfila, Larrey, Bouillaud, Royer,
Collard, and Teissier. — Edit.

1835.] Baron Dupuytren. ^3

officer whose regiment was passing through Pierre Buffiere.
Dupuytren was then twelve years of age, and was playing
in the public square. The officer observing him, asked him
some questions, and was answered with such intelligence
and readiness that he was astonished. He spoke to the
boy of Paris, and of the possibility of his taking him there.
Dupuytren received the proposal of the officer with joy,
quitted his play, bade adieu to his native town, and departed
for Paris with 10 francs (8s. 4d.) in his pocket. When he
arrived at Paris, Dupuytren was admitted into the College
of La Marche, of which the brother of the officer was rector.
There he distinguished himself, and carried off some prizes
for acquirements in philosophy. His talents were first
observed by Saint Simon, then by Thouret. The former, who
was the originator of a sect which has made a great noise
lately, and was made almost a diety, mounted one day to
the garret of Dupuytren. The cold was piercing, and the
student was studying in his bed. Saint Simon sat down
upon a frozen pan, conversed with Dupuytren, ahd on going
away, left on the pan tHe sum of 200 francs (£8. 6s. 8d.).
In ordinary cases the inhabitant of a garret would have
found means of laying out such a sum. But Dupuytren,
considering that he ought not to accept of it, went to Saint
Simon and said to him, " Sir, you left, by mistake, this
sum at my house, I beg to return it." Saint Simon only
replied, " it is true," and pocketed the money.

Thouret was soon convinced of the superior parts possessed
by Dupuytren, and used his exertions to have him settled
at Paris. When vacancies occurred at the great hospitals
of France, at Strasburg, or Montpellier, if a proposal was
made to Dupuytren to apply for them, he received it with
gratitude, but always refused, from a fear that he was not
fitted for the situation, and, at the same time, he pointed
out men who were worthy of the place. It was thus that
an excellent choice was made for Rouen, Montpellier, and
Clermont. Boyer, Corvisart, and Thouret, assisted in this
method of election adopted by Dupuytren.

Dupuytren, was earnestly requested to accept the chair
at Montpellier by some individuals; to whom Thouret
replied, that that city was not rich enough to recompense

g2

84 Biographical Account of [Aug.

such a man. In 1796, when scarce eighteen years of age,
he was made Prosecteiir at the Ecole de Sante.^

He was inspired with an indefatigable desire for the
study of anatomy, and gave a course which attracted a great
number of pupils.

In 1801 he was promoted to the head of the anatomical
department. Taking advantage of such an important
situation, he did not content himself with studying, merely,
the normal condition of organic structure, he prosecuted
also researches in reference to aberrations of form, and
thus contributed in assisting to lay the important founda-
tions of pathological anatomy. In 1803 IDupuytren was
nominated joint surgeon of the Hotel Dieu. He was not,
however, chief surgeon. He had formed a plan for the
operation of tying the subclavian artery, and an opportu-
nity occurred for putting it in practice ; but a superior will
was opposed to him, as he himself said. He soon, however,
afterwards performed this operation upon a patient. In
1812 he triumphed in a struggle which did him great
honour. By the Death of Sabatier the chair of surgery
became vacant. A number of very eminent surgeons were
candidates, among whom were Roux and Marjolin. He
succeeded, however, in obtaining the situation, by means
of his own talents and the influence of M. Pelletan, chief
surgeon. It has been often said that Dupuytren afterwards
forgot what this surgeon had done for him. The same
fault of memory is attributable to Desault; for history
states that Louis supported him by his credit, and had even
opened his purse for him. However, the patron did not
receive the gratitude from Desault which he had a right to
expect. But Louis did not abate in his exertions for the
surgeon's promotion. When, by the death of Moreau, the
place of chief surgeon of the Hotel Dieu became vacant, he
went and used his influence with the magistrate who had

* M. Vidal remarks here, that John Hunter, at the same age, could not read.
The French author might have known, that the poorest peasant in Scotland sends
his son to learn to read, as soon as he is able to walk from his father's dwelling
to the parish school, and, therefore, it was impossible that my immortal country-
man, whose father was of respectable rank, could have been excluded from a
privilege, to which the very beggar is admitted. We know, indeed, that his
education was finished at seventeen, when he went to Glasgow. — Edit.

1835.] Baron Dupuytren. 85'

the most power in the appointment of the surgeon. '* I
have," said Louis, " reason to complain of Desault, but I
owe it to the public interest to declare, that he is the man
best qualified for the situation.'*

At this competition, a circumstance occurred which
deserves to be mentioned. A day had been fixed for
giving in a certain number of copies of a thesis. This
injunction was of such a strict nature, that none were
allowed to compete, who did not accomplish it. The impor-
tant day arrived, and Dupuytren was not ready. Different
accounts have been given of the cause of this. Some attri-
bute it to the difficulty which Dupuytren experienced in
the composition of his thesis. Others say, that being dis-
satisfied with his first trials he wished to retire from the
contest ; but was anxious, at the same time, to make an
honourable retreat. Vidal has been supplied with a corres-
pondence, which has enabled him to give us the true version
of the story. Dupuytren did not always write badly, but
he wrote with great difficulty. Lebegue, who was his
printer, wrote him saying that it was impossible to have
his thesis ready in time, as he had made so many correc-
tions. Dupuytren seeing the impossibility of terminating
this competition, had resolved to retire, and had written a
letter to the Dean to this effect. But M. Crochard Senior,
who published a work on surgery commenced by this sur-
geon, requested permission to add to the titles already
acquired by the author, that of Professor of the Faculty.
This bookseller devised the following method for obtaining
the delay, which was necessary for completely finishing the
thesis of Dupuytren : He made the printer write a letter
stating that an accident had happened in the printing-office ;
that a workman had, while carrying a form, made a false
step, and allowed the form to fall among paste ; that time
would be required to prepare it for throwing off" an impres-
sion, and that Dupuytren could have no control over it.
M. Crochard went in great anxiety to the Dean, who was
much embarrassed. Dupuytren said he was ill. At last
M. Leroux terminated the matter by declaring that he
would grant the delay, if all the workmen in the printing-
office would attest the correctness of the fact by their signa-
tures. Immediately the attestation required was sent in.

96 Biographical Account of [Aug.

Dupuytren defended his thesis with the greatest success,
and was declared professor.

At the Hotel Dieu, where once Desault had exhibited his
remarkable enthusiasm for his favourite art, and where
Pelletan also flourished, Dupuytren became chief surgeon
in 1818, having been elected professor of clinical surgery
in 1815. In the hospital he displayed an astonishing degree
of activity, bestowing great attention on his lectures, which
were very well attended. Thus the admirers of Desault
and the friends of Pelletan immediately appreciated the
talents of Dupuytren.

He rose at sunrise, went to the Hotel Dieu, and only left it
at 11 o'clock. After his installation he wished to see and do
every thing himself. In the wards Dupuytren spoke little,
especially to the students. If any one wished to ask him a
question, it was necessary to do so before the visit, when
he was not occupied with the preparation of his day's lec-
ture. Notwithstanding the greatest precautions he some-
times answered with a disdainful look, which gave sad
offence. In this respect he differed greatly from the good
M. J. L. Petit, who instituted a course of surgery for the
express purpose of answering questions. M. Petit spoke
to the students with as great politeness as if he had been
addressing the most distinguished men of his time. The
surgeon of the Hotel Dieu answered sometimes ; but there
was something sharp and bitter in his replies, which silenced
the most intrepid of the students. When he arrived at the
patient's bed he remained for a moment, and addressed to the
sick generally three questions, in the mildest tone of voice.
If the patient gave a suitable answer the conversation was
continued in the same accent, but if his answers were not
connected properly with the questions, Dupuytren caught
his humour, and sometimes it was necessary for the patient
to become serious in order that he might recover the mild-
ness of his tone, which he should never have lost. Dupuy-
tren considered that patients had always a desire of con-
cealing the truth, or a part of the truth. It is melancholy
to confess that this idea was well founded. Those who have
attended the great hospitals can attest its truth. It is not
necessary here to investigate the causes of these mysteries
of the human mind, but it is proper to mention that this

1835.] JBaron Dupuytren. STJ

fact is well displayed among the hospital patients in
Paris.

To patients upon whom operations were performed, and
with children, Dupiiytren was always gentle, it might be
said even amiable. He possessed such an influence over
them, that in his presence they seldom complained of their
sufferings. He had a way of putting the question, " Are
you in pain,'' so, that he almost constantly received the
answer, '* iVb."

He employed this magnetic power to disconcert his asso-
ciate. If a phlegmonous tumour presented itself, he would
say, " Do you think, sir, there is pus here." If there was
fluid, the eye of Dupuytren would intimate a negative
answer to the professor. ^' Bring a bistoury," then would
exclaim the surgeon, and immediately a flow of purulent
matter took place. The poor associate obtained, however,
some consolation, for the whole day after, this great man
was uncommonly obliging to him. No one was less severe
to his victim than Dupuytren.* Generally, however, he
made a better use of this moral influence which he pos-
sessed in such a high degree. It is well known, that to
reduce certain dislocations, many diflSculties are experienced
from the contraction of the muscles. In order to remove
this effect, Dupuytren recommended taking off" the atten-
tion of the patient. He joined example with precept in a
most remarkable manner. One day a woman who did not
belong to the lowest rank was brought to the Hotel Dieu.
She had dislocated her arm, and all the trials which had
been made to reduce it had failed. Preparations were
made for employing extension and counter-extension. Two
attempts at reducing the luxation being unsuccessful,
Dupuytren cried out, *' Madam, one is never betrayed
except by their own family. You are addicted to wine,
your son told me so." The poor patient who was a woman
of uncommon temperate habits, was so much excited by
this exclamation that she fainted. Dupuytren took advan-
tage of this weakness and reduced the dislocation. He
then laughed and clapping her on the head, said, " I know
madam that you drink nothing but water."

* He would certainly assert his superiority in this way, at times, when any one
aspired to be ranked as his equal ; but of others he would not wantonly expose the
errors. He was more willing to aid than to chide the unassuming.

88 Biographical Account of [Aug.

Dupuytren possessed that species of eloquence which
classical authors term deliberative. If it was necessary to
persuade a patient of the necessity of undergoing a painful
operation, in Dupuytren was exhibited on that occasion,
how important the gift of language is to a surgeon. He
accomplished the expression of Cicero. ** Tantam vim
habet flexamina atque regina rerum oratio, ut non modo
inclinantem erigere, aut stantem inclinare, sed etiam adver-
santem et repugnantem rapere possit."

It was an interesting sight to witness Dupuytren instruct-
ing young children how to use their eyes, when he had given
them the use of these organs by an operation for congenital
cataract. Children in this predicament, instead of using
their eyes, are in the habit of stretching out their hands,
like animals destined to live in darkness. Our surgeon,
however, fixed their hands behind their backs, and standing
at the extremity of the ward with the patient at the other
end, and in presence of the students, he would call out,
*' Run my little fellow." This he could not do, but he
walked and soon reached the restorer of his sight. These
are traits in his character, which can never be erased from
the recollections of his students. It has been said that
'Dupuytren disliked men, and that he never loved any
body. It was injpossible for any one who had seen him
caress the little children in the circumstances mentioned,
to give credit to such statements. Even the enemies of
Dupuytren, granted that he excelled in a high degree in
forming a diagnosis. ^ The following fact illustrates this
in a striking point of view. A man had received a con-
siderable time before he applied to Dupuytren, a blow on
the head. The original accident was not severe, but
nervous symptoms subsequently appeared, which obliged
him to apply to a surgeon. Dupuytren having examined
the man, said to his assistants, " Have the trepanning in-
struments ready to-morrow." The students were astonished

• His confidence in his own diagnosis was unlimited and inflexible. In con-
sultations, Mr. King has known him stand alone in an opinion, and at last obtain
permission to prove its correctness by an operation, which, if it had not fulfilled
his predictions, would have gone far to ruin him. And thus, and not by idle
boasting, he obtained a reputation which nothing could shake. How he silenced
his opponents they well can bear witness who saw him plunge a knife many inches
deep in the lumbar region, to let out pus, which, contrary to their opinion, his
seldom-erring; touch had detected there.

1835.] Baron Dupaytren. 89

at this decision, as the symptoms did not appear to them
to require such a serious cure. But Dupuytren had de-
tected (or divined some might say) the presence of an
ahscess in the cerebral matter. The bone was sawn through ;
no diseased appearance was exhibited; the dura matter
was healthy; it was cut through and still no disease appeared.
It was then that Dupuytren, with a degree of boldness
which has seldom been equalled in the annals of surgery,
plunged a bistoury into the substance of the brain. An
abundant discharge of purulent matter was the conse-
quence !

The diagnosis of abscess in the iliac fossa is a difficult
matter, yet Dupuytren gave admirable rules for detecting
it, and by this means saved the life of a commissary.
Numerous other instances of his diagnostic powers are
well remembered. A lady had been treated during several
years for cancer of the uterus. A surgeon of distinction
had so designated the disease. Dupuytren was at last com-
sulted ; he declared that the disease was polypus, and
that an operation would be attended with perfect success.
He operated, and in three days the lady went to the opera.

A woman was admitted into the Hotel Dieu with con-
siderable swelling of one of the tonsils. All those who saw
the woman before the arrival of Dupuytren, considered the
case to be one of simple inflammation of the gland. He
came and gave it as his opinion that a cyst existed in the
tonsil, and that there were other cysts in some part, more
or less distant from the throat, which had a great tendency
to inflame by a kind of sympathy which united them. The
cyst was removed to the great astonishment of those assem-
bled. Next day erysipelas of the face appeared, and pain
in one of the kidneys. '' It is in this organ, said the
great surgeon, that the second cyst exists ; it is inflamed,
and we are in danger of losing our patient ; " a circum-
stance which happened notwithstanding the best directed
treatment.

The inspection after death confirmed the accuracy of his
diagnosis.

It has been said that Dupuytren gave his diagnosis always
with great rapidity, and some gave credit to the idea of his
infallibility.

In many cases, it is well known, that a single glance

90 JBiographical Account of fAuG.

was sufficient to satisfy him of the nature of the disease.
A few days before his death, a man was brought to him with
a dislocation of the elbow joint; he did not touch the
patient, but declared that displacement of the articulation
existed. A distinguished surgeon denied that it was a dis-
location. M. Sanson, however, examined it, and reduced
it. But Dupuytren did not always give his opinion so
readily, which shews that what some considered instinct,
was in him the result of a series of reasonings.

When he examined a dislocation of old standing, and
of which the diagnosis was difficult, he did not prolong
his examination beyond the usual time, but he spoke of
the circumstance, neither in the wards nor in the theatre.
Next day the patient was examined, and if the disease
was not recognized, silence was preserved. But on the day
when Dupuytren could touch the luxation with his finger,
an excellent clinical lecture was delivered. He spoke
then of the patient as if he had seen him for the first time,
and in the most positive manner, established the diagnosis,
the treatment, and the prognosis of the disease. Dupuytren
seldom expressed his doubts to his audience. If he doubted,'
it might be assumed that he was giving utterance to a cer-
tainty. When he explained his diagnosis he never followed
out the steps of his reasoning, which gave him a degree of
superiority, but did not satisfy. Vidal remarks, that it
would have been preferable if the professor had communi-
cated his doubts, and thus have exhibited a view of the
intellectual process by which he arrived at his conclusion.
But perhaps he did not consider it political to initiate
others into his thoughts. *

To those who reproached him for speaking sparingly of
his mistakes in practice, it hag been answered that he com-
mitted few. He perhaps supposed that some of his friends
would undertake this trouble for him ; but such an exposure
comes best from one's own mouth. M. Roux and M.
Marjolin are always in the habit of stating their unsuccess-
ful cases, and have consequently established for themselves

♦ This observation is not considered just by Mr. King. For, it was, in fact,
by teaching so well how to form a correct diagnosis that he attracted so large an
audience ; and be spared no pains to exj)lain this difficult art, in a manner, which,
while it instructed the experienced practitioner, had so much method, clearness
and simplicity that it could be easily followed by the student.

1 836 .] Baron Dupuytren . 9 1

characters of candour, which is of the greatest consequence
in a teacher. Vidal, however, states, that he has often
heard Dupuytren confess his errors, when he was not re-
quired to do so.

If he overlooked his own errors, it is also certain that
he was as lenient in public to his cotemporaries, which
some have explained, by saying that he only spoke of him-
self, and never mentioned at the Hotel Dieu the names of
other surgeons. This, however, is a great mistake, for
although he preferred his own experience to that of others,
yet he often mentioned in his lectures, Sir Astley Cooper,
Scarpa, and Boyer. His mode of mentioning these great
surgeons, shewed what he thought of his contemporary in
Britain, of the talents of the professor of Pavia, and the
veneration which he had for the author of the " Traite des
Maladies Chirurgicales." No one appreciated the good
sense of Boyer more than Dupuytren.*

It was in the operating theatre that Dupuytren shone
most, where the most distinguished surgeons of all countries
have been seated around him, where he taught surgery
with dignity, where no vulgar pleasantries or brutal
expressions were ever uttered by him. In his clinical
lectures, he explained facts with the greatest clearness,
and with such a number of details, as to surprise even those
who continued to attend him for a long period. When he
had developed a fact, he compared it with analogous cases
which had occurred in the Hotel Dieu, or in his private
practice, and thus proved that he had seen much, and that
his experience was accompanied with practical benefits.
For among the higher classes there are modifications of
disease which differ from those among the poorer class,
and there are complaints which follow from the indulgence
in luxuries. Dupuytren was the surgeon of the rich and

* He was by no means lavish in his praise, but it was not easy for him to be
unjust to those who had distinguished themselves in that field by which he rose to
eminence himself; for, to use his own words, the name of Concours caused his
heart to beat with emotion. An instance of this feeling is afforded in his conduct
to Mr. King, who was elected house-surgeon to the Parisian hospitals by a
public Concours. Dupuytren was one of the jury. Previous to the trial he had
shewn himself averse to the admission of foreigners, as candidates ; but, afterwards
he became favourable to it, and declared that, in this case, he deemed the appoint-
ment so well gained, that he would add to it whatever services he could fairly
render Mr. King. And in this he kept liis word.

92 Biographical Account of [Aug.

the poor, and he knew how to make his experience in both
ranks bear upon the developement of facts.

Dupuytren did not possess the manual dexterity which
is so much admired in M. Roux ; but his knowledge of
organic structure, his talent for diagnosis, enabled him to
establish the indications with certainty, and to seize the
means of preventing accidents, and of overcoming them
when they occurred. He knew well how to calculate the
strength of the vital powers. There are some surgeons
who can perform operations with skill, but who do not
know when to avoid them. Dupuytren possessed both
these talents.

A circumstance which gave an awkward appearance to
Dupuytren's mode of operating, was his anxiety to give
clinical instruction to the students. For example, in
amputation of the mamma, instead of placing himself
before the patient, he often stood behind her, in order that
he might not obstruct the view of the students. He
frequently departed from the common rules, from mere
caprice, or from forgetfulness, or perhaps even from igno-
rance of these rules. He not only chose the most favourable
position for the spectators, but he also explained the dif-
ferent steps of the operation as he proceeded, which shewed
great coolness and presence of mind. But his greatest talent
was displayed when unexpected accidents occurred during
an operation. The operation was never in the least re-
tarded by such an exigency ; a new plan was immediately
devised, and if the surgeon did not inform the spectators
of what had happened, the latter would have been quite
unaware of it. But he never allowed an opportunity to
pass of exhibiting the utility of his new plan.

Vidal only once saw him lose his presence of mind. He
had to extract a very large calculus : he considered a long
time how he should proceed. He appeared to adopt the
idea of cutting the fundus of the bladder ; but still he
hesitated. At last what was most extraordinary, he allowed
himself to be influenced by the advice of another surgeon,
who advised him to combine the bilateral with the recto-
prostatic incision. He operated, but did not succeed, for
the calculus was not extracted till next day. On that day,
Vidal observed his lower lip to quiver, and his cheeks to
change colour several times, and this because the school

1835.] Ba/Fon Dupuytren. 93

disapproved of his mode of operating. It was said, why did
he not stop when he saw the difficulties of the case, and
finish it by several steps, placing the patient in the intervals
in the bath 1 Franco, Camper, Louis, &c., have given
examples of this method of proceeding, even when there
was no necessity for it. After operating, Dupuytren held
a consultation for the benefit of his patient. It was a kind
of clinical lecture, in which he heard the opinions of the
advanced students. This ought to have fatigued him.
But if in departing from the hospital, a journalist who had
not obtained sufficient matter for an article, came up to him
to request some, Dupuytren did not remain, but in his walk
prolonged his lecture, so as to allow the writer to take
hasty notes. Vidal has seen Dupuytren dressed in plain
green when the snow was on the ground, walking along
the bridges and dictating to M. Paillard who accompanied
him. Thus many lectures which have been published, as
being delivered at the Hotel Dieu, were actually produced
on the Pont Neuf. But Dupuytren was always a professor,
in the transactions at the Faculty, at the Academy of
Medicine, and even at the Institute.

In 1825, he was admitted a member of the Academy of
Sciences. In July, 1830, he distinguished himself most
conspicuously by his attention to the wounded, and delivered
some excellent lectures upon gun-shot wounds, which have
been reported and published by his students. Dupuytren
occupied the situations of Inspector of the University,
Surgeon to Louis XVIII., and Charles X. He was an
Officer of the Legion of Honour, and a Baron. His name
was extensively known, for he had attained the summit of
his profession. At last his constitution began to fail.
About November, 1833, symptoms of hydro thorax appeared,
Dupuytren still however continued to appear in public with
his usual regularity. M. Bouillaud (to whom with Husson,
Cruveilhier, Marx, and Sanson, Dupuytren entrusted him-
self) has eloquently described the death-bed scene of the
great surgeon. *' After tedious and painful suffering Du-
puytren saw that all hope of cure was at an end ; he resigned
himself then with the most stoical fortitude, and preserved
till the last moment, all his presence of mind and his clear-
ness of judgment. He never uttered a word expressive of

94 Biographical Account of [Aug.

the slightest weakness. During an agony of eight days he
remained completely master of himself. Each instant of
his life during this painful and tedious martyrdom, seemed
miraculous to those who were near him. Death appeared
to hesitate to strike so great a victim, and to destroy an
organization which nature had so strongly moulded."
Notwithstanding his great capacity for diagnosis, Dupuytren
remained long in doubt of the presence of fluid in his chest,
and when he was convinced of the fact, he considered that
the liquid was contained in cysts. This was the reason
why he refused to undergo an operation, twelve days
before his death, when urged to it by M. Sanson. Until
the fourth day previous to his death he entertained a spark
of hope. Sometimes even he believed his health re-esta-
blished. Nature at length entirely failed, and the dis-
tinguished Baron breathed his last on the morning of the
8th of February, 1835, about half-past 3.=^

If distinction as a surgeon depends upon original inven-
tion, as in the cases of Pare, Franco, Hunter, and Pott,
then Dupuytren cannot lay claim to it ; but he was an excel-
lent clinical professor, and has made a great many good
surgeons who are distributed over different parts of the
world. He has endeavoured to simplify the study of
surgery by making it less mechanical, and at the same time
more successful .f He wrote papers upon different profes-
sional subjects.

1. Surgery. — The memoir of Dupuytren upon the artifi-
cial anus constitutes his principal scientific work. It forms

* Dupuytren possessed a remarkably fine person and strong constitution. The
decline of his health was sudden, and unexpected by his friends, and, therefore,
the more painful to them. By his physical strength and mental power he seemed
predestined to a green old age. He could go through immense bodily exertion ;
his mind was ever active ; and, up to a recent period, he had scarcely known a
day's illness. The cause, the great cause of his fall, was an extremely irritable
temper. This was a source of unceasing mental suflFering, and his nervous
system, at last, gave way under it. This was his great misfortune ; for, after the
death of such a man, we say misfortune rather than fault. It made him insup-
portably capricious and inconsistent, and often impelled him to rash and wrong
acts, which, on reflection, in cooler moments, he would fain have recalled.

t He is said to have left his daughter, Madame de Beaumont, a fortune of nearly
7,000,000 of francs, (about £296,000), and, besides, 20,000 (£ 8,333) to found
a Professorship of Medico — Chirurgical Pathology ; and 300,000 (£ 12,500) for a
House of Retirement for Twelve Superannuated Medical Men. — Edit.

1835.] Baron Dupuytren. 95

a happy application of the principles so well developed by
John Hunter.

In 1815, he road to the Institute a memoir upon ligature
of the arteries, substituted for amputation of the limbs in
cases of fracture, complicated with aneurisms.

He also wrote upon the ligature of the arteries, practised
according to the method of Anel, in certain cases of division
of these vessels produced by lightning.

In 1816, he read to the Institute a paper on the ligature
of the principal arterial trunks. The other surgical writ-
ings of Dupuytren were upon congenital dislocations of
the femur, and old dislocations in general, on retraction of
the finger and strangulated hernia. He edited the new
edition of Sabatier's work.

2. Pathological Anatomy. — Under this head may be men-
tioned, his numerous researches in the bulletins of the
faculty of medicine, relating to cellular, mucous, cartila-
ginous, and osseous transformations, on fibrous, fatty, in-
cysted products, and on scrofulous, cancerous, and schir-
rous degenerations.

In his researches on callus, published in 1831 , he endeavours
to shew, that in consequence of fractures, there are two
kinds of callus formed, temporary and permanent. In
1803, he published observations on false membranes, where
he investigates the causes, progress, expulsion, or organi-
zation of false membranes, the advantages and incon-
veniences of their formation from inflammation in the
serous, sinovial and mucous membranes.

3. Anatomy. — His Observations on the spleen shew that
animals may live, exercise their functions, re-produce their
species, although deprived of this organ.

In 1803, he published. Investigations on the Veins of the
Bones.

Observations on the fibrous tissues. He divides these struc-
tures into white fibrous, non-elastic tissues, and yellow
elastic tissues.

His Researches on the erectile tissues were published in 1816.

4. Physiology . — Experiments on the nerves of the tongue.
These demonstrate that some of the nerves of the tongue
are destined for the purposes of motion, and others for those
of sensation.

96 Biographical Account of [Aug.

Memoirs in the motions on the brain. This work shews
that the two motions observable in the brain are the result
of the influence of the circulation, and of the respiration
on this organ.

Analysis of the Chyle, 1803.

Experiments on the influence exercised by the nerves of the
Sthpair, on the respiration of animals. — (Memoir read to the
Institute, 1812.)

Experiments upon absorption. In this paper it is proved
that bodies are more readily absorbed in proportion to their
irritating power ; that their first effect is to increase exhala-
tion, the second to augment absorption, and the third to
produce inflammation, and that substances are always altered
in their state and nature, before being absorbed.

5. Medicine — Experiments on Diabetes Mellitus.

Researches on the air of common sewers. He considers its
composition to be sulphuretted hydrogen, disengaged by
the[putrid matter and azote, resulting from the decomposi-
tion of the air of ditches.

Dupuytren also wrote on yellow fever and cholera, and
the biographies of Corvisart, Pinel and Richard.

According to his request, his body was examined 32 hours
after death, on the 9th of February. The following dimen-
sions were obtained in measuring the head : —
From the frontal prominence to the occipital

protuberance 14^ inches.

Circumference of the head by the frontal and

occipital protuberance 22^

From the anterior part of one meatus audi-
torius externus to the other, passing over

the head 13|^

Occipito nasal diameter 7 J ,,

From the frontal prominence to the root of

the brain (height of forehead), nearly .4 ,,

The cerebrum, cerebellum, annular protuberance and
medulla oblongata, weighed together 3flbs. troy.

The cerebellum by itself weighed 4|Joz.

In the right corpus striatum without the optic layer,
there was an excavation with brown sides, capable of holding
a filbert. In the corresponding position on the left side a
similar apoplectic cavity was detected. These were crossed
by cellular bridles.

5>

5»

1835.] Baron Dupuytren. 97

A trochar being plunged into the chest, on the right side,
above eight English pints of a milky serum escaped. Some
fibro-cellular bridles were observed in the right cavity of
the chest, at the bottom of which a membranous mass
existed, resembling concreted albumen. The pulmonary
pleura had a milky appearance. The tissue of the inferior
lobe of the right lung was condensed, as if converted into
flesh ; the cells contained no air, and the lung sunk in
water. The middle lobe, and the lower portion of the
superior lobe were infiltrated with a slightly reddish serum.
The superior part of the lung alone crepitated, and con-
tained a very great quantity of air.

The left side of the chest contained at the lower part,
about an English pint of transparent serum, coloured by a
few drops of blood. Some old organized adhesions were
observed. The left lung was of its usual size, was slightly
infiltrated, and did not fall to the bottom of water. The
pericardium contained only a few drops of serum. The
heart was hypertrophied, well formed, and surrounded with
a very great quantity of fat. Its tissue was soft, brownish,
and appeared to be decomposing. The internal surface of
the aorta, and of the large arteries, was covered with
yellowish fibro-cartilaginous points, all, however, unossified.
The coats of the arteries were thick, and hypertrophied like
the heart.

The rest of the organs seemed to be healthy, except the
kidnies, which were smaller than natural and contained*
some sand.

Article II.

On Racemic Acid, By Thomas Thomson, M.D., &c., Regius
Professor of Chemistry in the University of Glasgow.

This acid was first noticed about the year 1817, by a manu-
facturer of tartaric acid, at Thann, a small town in the
Vosges, who considered it as oxalic acid, and sold it as
such. It was subjected to examination in 1819 by Dr.
John, who proved it to be a peculiar acid to which the
name trauhensaure (acid of grapes) was given by the
Germans. This name I translated by vinic acid in the last
edition of my System of Chemistry. But the term racemic

VOL. II. H

98 Dr, Thomas Thomson [Aug.

acid given by the French is preferable ; because vinic is the
name applied frequently on the Continent to tartaric acid.
In 1829 it was subjected to an examination by Gay-Lussac
and by Walchner, and the result of their experiments leaves
no doubt that it possesses peculiar properties. In 1830 it
was analyzed by Berzelius, who found its constituents and
its atomic weight the same as those of tartaric acid. On
that account he has given it the name of paratartaric acid.

It seems to be formed during the process for extracting
tartaric acid from cream of tartar. When the tartaric
acid is crystallized for the first time, we observe mixed
with its crystals, a number of small needles. These on
examination are found to be racemic acid. Under the
microscope they assume the form of long oblique four-
sided prisms, usually terminated by an oblique face. By a
second crystallization they may be obtained in large doubly
oblique prisms. The terminating face is inclined to the
sides of the prism, at an angle of 75°, the one side to the
other at an angle of 68°. The longitudinal edges of the
prism (at least two of them) are usually replaced by tan-
gent planes, converting it into a six or eight-sided prism.
Not unfrequently one of the terminal edges of the prism
is also replaced by a plane, thus rendering the summit
of the prism two faces applied to each other like the roof
of a house.

Tartaric acid forms very large but rather irregular crystals.
They may be obtained an inch and a half in length and
about 0*7 inch thick. The primary form of this acid is a
doubly oblique prism, but the angles are different. The
terminating face is inclined to the sides of the prism, at an
angle of 97*10°, and the one side to the other at an angle
of 88-30°.

The edge is usually replaced by a very broad plane,
which renders the terminal face of the crystal triangular,
and gives to its upper surface the aspect of that variety of
calcareous spar called tete de clou.

The lustre of racemic acid is silky, that of tartaric acid
glossy. The specific gravity of racemic acid crystals is only
1-600, while that of tartaric acid is 2-083.

Racemic acid when heated to 150° loses its crystalline
form, and gives out 5*59 per cent, of water. At the same

1835.] on Racemic Acid. 99

temperature the crystals of tartaric acid undergo no change
and lose no weight. When the heat is increased, racemic
acid undergoes no further change till it reach the tempera-
ture of 370°, when it becomes yellow at the bottom, be-
ginning to undergo decomposition. At 250° tartaric acid
liquifies and loses about 4 per cent, of its weight. The liquid
is transparent. On cooling it becomes solid and resembles
a piece of crystal glass. Thus altered it slowly imbibes
moisture from the atmosphere and runs into a liquid.

At the temperature of 49°, 100 parts of water dissolve
14*1 of racemic acid crystals. At the same temperature
100 parts of water dissolve 64*8 of tartaric acid. Thus at
the temperature of 49°, tartaric acid is about 4 J times more
soluble than racemic acid.

At the temperature of 1 ip° 1 00 parts of water dissolve
37*94 of racemic acid and 80-48 of tartaric acid. These
facts shew that tartaric acid is much more soluble in water
than racemic acid.

Racemic acid may be used as well as tartaric acid to
prevent a solution of antimony in muriatic acid from being
precipitated when diluted with water. In this property the
two acids agree, proving that racemic acid has the same
tendency to enter into triple combinations as tartaric acid.

A striking difference between tartaric and racemic acid
is exhibited when we drop solutions of these acids into
chloride of calcium dissolved in water. The former occa-
sions no precipitate, while the latter throws^down a copious
deposit. Thus, we see that racemic is a more powerful acid
than tartaric. Accordingly, it is capable of decomposing
various tartrates and taking the place of the acid.

Atomic weight of Racemic Acid.

The following experiments were made in order to deter-
mine the atomic weight of this acid. Some trials made in
the year 1827 in my laboratory by a very ingenious pupil,
had led me to infer that 8*5 represented the atomic weight,
but they were not of such a nature as to decide the point.
Those that I shall now relate were made by myself with
every attention to accuracy.

1 . One hundred and seven grains of crystals of racemic
acid were triturated in a mortar and exposed for 24 hours in

h2

100 Dr. Thomas Thomson [Aug.

the vacuum of an air pump over sulphuric acid. The
weight was reduced to 105-05 grains. This loss amounting
to 1*822 per cent, was owing to the escape of water lodged
mechanically between the plates of the crystals.

2. Twenty grains of litharge previously dried in a tem-
perature of 300°, were triturated in a porcelain mortar
with 10*5 grains of crystals of racemic acid and a little
water, till the liquid ceased to affect litmus paper. The
whole was then dried for some hours on a sand bath heated
to 300°. The weight was reduced to 28*19 grains. So
that the ten grains of acid had lost 2*31 grains which
must have been water. Of this 0*192 grains was mechani-
cally lodged water. Consequently 2*118 grains of water
must have been chemically combined in the crystals with
pure racemic acid. Thus, the crystals (supposing the
mechanically lodged water removed) were composed of
Real acid . . . 8*19 or 8*25
Water .... 2*118 or 2*133
I repeated the experiment, and exposed the litharge and
acid to a higher temperature. The white colour of the
powder at the bottom of the glass capsule had a decided
mixture of yellowish gray, shewing that the acid had begun
to undergo decomposition. The weight was reduced to
27*90 grains. So that the loss of weight sustained by the acid
was 2*51 grains. Of this 0*192 was mechanically lodged
water. The remainder amounting to 2*318, obviously
rather exceeds the whole chemically combined water con-
tained in the crystals.

According to this experiment the crystals of racemic
acid are composed of

Real acid . . . 7*99 or 8*25
Water .... 2*318 or 2*393
It is obvious, that in the first of these experiments, the
chemically combined water is reckoned below the truth,
because the salt had not been sufficiently dried : while in
the second experiment it is above the truth, because the
salt had been exposed to so high a temperature as to occa-
sion an incipient decomposition of the acid. The truth
must lie between the two. Now, a mean of the two experi-
ments gives us 2*263 for the water chemically united with
8*25 of acid. This approaches so near 2*25, the weight of

1835.] on Racemic Acid. 101

two atoms of water, that we can entertain no doubt that
the crystals consist of a compound of one atom of acid with
two atoms of water. Why I have pitched upon 8'25 for the
weight of the acid will appear immediately.

Tartaric acid crystals consist of only 1 atom of water
united to 1 atom of acid. It contains, therefore, just half
the water in racemic acid ; but with this water it will not
part without undergoing decomposition. Racemic acid,
when heated to 150° gives off one-fourth of its water ; at the
same temperature tartaric acid loses no weight whatever.

3. 20 grs. of neutral racemate of lead (previously dried
in a low heat) were exposed for two hours on a glass capsule
to the temperature of 250°. The weight was reduced to
16*16 grs. The heat being continued for two hours longer,
and raised a little higher, the weight was reduced to 16*12
grs. But the powder where in contact with the glass had
become yellow, indicating an incipient decomposition of
the acid.

The residual 16*12 grs. were ignited in a porcelain cruci-
ble. Most of the lead was reduced to the metallic state.
The whole weight was 9*49 grs. Of this 9*18 grs. were
metallic lead, and 0*1 gr. protoxide of lead. The remaining
0*2 gr. were probably charcoal from the acid, for they
disappeared on treating the lead with nitric acid. Now,
9*18 lead + 0*1 protoxide of lead = 10*188 grs. of pro-
toxide of lead. It would appear then, from this experiment,
that racemate of lead is a compound of,

Racemic acid 5*972 or 8*206

Protoxide of lead . . . .10*188 „ 14*

16*160

The result of this analysis gives us 8 206 for the atomic
weight of racemic acid. The only ground of doubt respecting
this analysis is the uncertainty whether any of the acid had
been decomposed by the heat. So far as the eye could
determine the salt was unchanged.

4. An analysis of racemate of lime conducted in the same
way led to results not differing much from the preceding ;
it seems, therefore, needless to detail the analysis. For
the same reason the details of the analyses of racemate of
barytes and racemate of strontian, which were also made.

\9Si Dr. Thomas Thomson [Aug.

need not be here stated. I put more dependence upon the
following' synthetical experiment than upon any of the
analytical ones that I made, because it is susceptible of
greater precision than any of them. Indeed, I consider it
as approaching as near the truth as it is possible to do by
our present methods.

5. 86*76 grs. of pure fused carbonate of potash were
dissolved in water, and to the solution 102 grs. of crystals
of racemic acid were added by degrees till they were com-
pletely dissolved. The liquid was found still to contain an ex-
cess of potash ; for it rendered cudbear paper violet. After
adding 4*34 grs. of racemic acid, (previously dissolved in
water) and agitating the mixture well, it was found still to
render cudbear paper violet. This led me to suspect that
cudbear paper is not capable of determining the exact point
of saturation of carbonate of potash by racemic acid. The
whole liquor was put into a platinum basin and evaporated
down till it amounted only to IJ cubic inch. It was still
liquid, and perfectly transparent, and still acted on cudbear
paper like an alkali. 1*1 grs. of racemic acid was added,
the liquid was gently heated and set aside. It soon became
muddy, and deposited a quantity of bi-racemate of potash,
which, after being separated and dried, weighed (including
the small quantity still left in solution) 3.3 grs.

Now, 3*3 grs. of bi-racemate of potash contain 2*42 grs.
of racemic acid, the half of which must be the amount of
the excess of racemic acid added to the carbonate of potash,
over and above what was necessary to neutralize it. But
1*21 grs. of real racemic acid, to bring them to the state of
the crystals, require to be combined with 0*359 grs. of
water. This makes 1*569 grs., which, when subtracted
from 107*44, leaves 105*871 grs. of the crystals of racemic ■
acid, as the quantity which neutralized 86*76 grs. of carbo-
nate of potash.

105*871 grs. of crystals, when deprived of their mechani-
cally mixed water, would be reduced to 103*913 grs. From
the preceding analysis of these crystals it follows that they
are composed of

Real acid 81*544

Water 22*369

103*913

1835.] on Racemic Acid, 103

But 86-78 grs. of carbonate of potash contain 59*49 grs. of
potash. Consequently, racemate of potash is composed of
Racemic acid . . . 81*544 or 8*224
Potash 59-492 „ 6*

141*036
The only source of uncertainty in this experiment is the
quantity of bi-racemate of potash, which I supposed to be
dissolved in the IJ cubic inch of liquid from which the
bi-racemate had fallen. I estimated it at 1*6 gr., reckoning
its solubility in water containing racemate of potash, two-
thirds of that in pure water. The quantity of salt in solu-
tion was only the third part of what it is capable of taking
up ; but this portion of salt may have diminished the solu-
bility more than I supposed. If so, I have under-rated the
quantity of racemic acid requisite to saturate the potash.

6. I am inclined to believe that the atomic weight is a
little higher than I made it ; because Berzelius has found
the constituents, and, of course, the composition of racemic
acid the same as of tartaric acid. Now, it has been ascer-
tained that the constituents of tartaric acid are,

4 atoms carbon ... 3*

2 ,, hydrogen . . 0*25

5 „ oxygen . . 5*

8*25
This makes the atomic weight of both these acids 8*25.
My result comes within less than -j^oth of that number.
There cannot then, I think, be any reason to doubt that
the atom of racemic acid is 8*25, and that its crystals are
composed of 1 atom acid . . . 8*25

2 atoms water . . 2*25

10*5
So that the atomic weight of the crystals is 10*5

Let us now take a view of the different salts which race-
mic acid forms with the bases, and compare them with the
corresponding tartrates.

I. RACEMATE OF AMMONIA.

The best way to form this salt is to add a solution of
racemic acid to the liquid carbonate of ammonia, till H

104 Dt. Thomas Thomson [Aug.

reddens litmus paper. If we reverse this process by pouring
carbonate of ammonia into a solution of racemic acid, bi-ra-
cemate of ammonia soon appears and renders the neutraliza-
tion of the acid tedious. When the concentrated solution
of racemate of ammonia is set aside, beautiful crystals are
deposited.

The crystals are long four-sided prisms, terminated by two
faces applied to each other like the roof of a house. The
primary form seems to be a doubly oblique four-sided prism ;
the sides being inclined at an angle of 94*45°. When
these crystals are exposed to the air they effloresce lightly,
and assume a silky lustre. In that state their specific
gravity is 1*639.

When the salt is distilled it does not melt, but gives off
water and speedily acquires a dark colour. A black bulky
charcoal remains after the process, and a dark brown liquid
passes over, having an empyreumatic smell, and the receiver
is filled with fumes of ammonia. Feather-shaped crystals
of carbonate of ammonia are gradually deposited in the
beak of the retort.

The taste of racemate of ammonia is saline, but it leaves
a disagreeable impression in the mouth, somewhat like that
of nitre. At the temperature of 60° 100 parts of water
dissolve 14*58 parts of the effloresced crystals. The solu-
bility increases with the temperature. The salt is scarcely,
if at all, soluble in absolute alcohol.

To determine the constituents of this salt, 107 grs. of the
crystals of racemic acid, which have been shown above to be
equivalent to 82*5 grs. of real acid, were saturated with
carbonate of ammonia, and the liquid evaporated to dry-
ness in a gentle heat. The silky crystals obtained were
neutral, and weighed 111 grs. Now, 82*5 grs. of racemic
acid require for neutralization 21*25 grs. of ammonia.

Consequently, the salt was composed of,

Racemic acid . . . 82*5 or 8*25

Ammonia 21*25,, 2*125

Water 7*25 „ 0*725

111*00
0*725 exceeds the weight of half an atom of water by 0*1525,
or about |th of an atom. This smajl excess is, doubtless,

1835.] on Racemic Acid. 105

lodged mechanically in the plates of the crystals. The
chemical constituents of racemate of ammonia are obviously
1 atom acid .... 8*25
1 ,, ammonia . . 2*125
J ,, water . . . 0*5625

10-9375

When ammonia or its carbonate is cautiously dropt into
a solution of racemic acid, bi-racemate of ammonia falls in
bulky flocks, consisting of minute crystals. It resembles
bi-tartrate of ammonia closely, both in its appearance and
solubility in water. '

Tartrate of Ammonia.

This salt may be formed precisely in the same way as the
racemate, only substituting tartaric for racemic acid.

Its taste is sa],ine, and very similar to that of sal-ammo-
niac. It usually forms small gritty crystals. But it may be
obtained in large transparent, four-sided, rectangular prisms,
terminated by a face inclined at angles of 120° and 60°, to
the two opposite faces of the prism. In general all the
edges of the prism are replaced by tangent planes, making
an eight-sided prism, with angles of 135°.

At 55° 100 water dissolve 60*03 parts of these crystals,
so that it is at least four times as soluble in water as race-
mate of ammonia.

Its constituents, determined in the same way as those of
racemate of ammonia, were found to be,

1 atom tartaric acid . . 8*25
1 ,, ammonia . . . 2*125
1 ,, water .... 1*125

11*5
Thus it differs from racemate of ammonia in the shape of

its crystals, in its solubility in water, and in the water of

crystallization being twice as great.

When heated it smokes, becomes brown and swells up

like a burning feather, without flaming, leaving a coal

which burns very slowly but completely, without leaving

any residue.

106 Dr. Thomas Thomson [Aug.

II. RACEMATE OF POTASH.

This salt is easily procured by saturating liquid racemic
acid with carbonate of potash, and concentrating the solu-
tion till it deposits crystals.

The crystals of this salt are large transparent prisms.
The primary form seems to be a right oblique four-sided
prism. The faces of which are inclined to each other
nearly at angles of 120° and 60°. The edges 60° are usually
replaced by planes, which, however, are not tangent planes,
as they form unequal angles with the two adjacent faces of
the prism. Sometimes all the four edges are replaced,
making the prism eight-sided. The terminal edges are
always replaced by tangent planes, which frequently con-
ceal the terminal plane and convert the summit of the
crystal into a four-sided pyramid, with very unequal faces
in point of size.

The taste of the salt is saline, harsh and bitter. Its
specific gravity is 2*08. It is not sensibly soluble in alcohol.
At the temperature of 55° 100 water dissolve 112*59 of the
crystallized salt.

It has been shewn in a preceding part of this paper, that
the salt is a compound of 1 atom acid and 1 atom potash.
To determine the quantity of water, 87*5 grains of anhydrous
carbonate of potash were just saturated with crystals of
racemic acid. The solution being evaporated to dryness
in a gentle heat weighed 155*7 grains. Now, it contained
60 grains of potash and 82*5 of racemic acid. Hence, its
constituents were obviously

1 atom racemic acid . . 8*25
1 atom potash .... 6*00
Water 1-32

15-57
1*32 exceeds an atom of water by about ^th of an atom.
This small excess, doubtless, consisted of water lodged
mechanically among the particles of the salt. The chemi-
cally combined water in the salt is 1 atom or 1*125, and
the atomic weight of the crystals 15*375.

When racemate of potash is heated, it melts and gives off
water. It then becomes brown, swells up and the acid is
decomposed. But it scarcely burns with flame unless when

1835.] on Eacemic Acid. 107

brought in contact with a flaming body. It is next to im-
possible to burn off the whole of the charcoal, the potash
even after fusion retaining a black colour.

Tartrate of Potash.
This salt long known by the name of soluble tartar, forms
large crystals as transparent as glass. Their primary form
is a right oblique prism, deviating but little from rectangu-
lar : the inclination of the faces of the prism being 89° 30'
and 90° 30'. The obtuse edges of the prism are usually
replaced by tangent planes.

It has a saline and unpleasantly bitter taste. Its specific
gravity is 2*140. If Wentzel's statement that water at
50° dissolves its own weight of it be correct, it possesses
nearly the solubility of racemate of potash.

To determine the composition of this salt, 93*75 grains
of dry crystals of tartaric acid, were exactly saturated with
carbonate of potash, the solution was evaporated to dry-
ness and kept in the temperature of 100° till it ceased to
lose weight. In this state it had a moist appearance and
weighed 171*95 grains. Now, it contained 82*5 of tartaric
acid and 60 of potash. Hence,' its constituents were
Tartaric acid . . . . 8*25

Potash 6*00

Water 2*945

17*195
2*945 of water is very nearly 2 J atoms. Hence, it would
appear that this salt when dried at 100° contains 2| atoms
of combined water. When kept for three hours in the
temperature of about 300°, the weight was reduced to 137*7
grains. Thus it had lost all its water and a portion of its
acid had been dissipated.

III. BI-RACEMATE OF POTASH.

This salt is obtained with great ease if we dissolve 214
grains of the crystals of racemic acid in water, and add to
the liquid by a little at a time, a concentrated solution of
87*5 grains of anhydrous carbonate of potash. After the
effervescence is at an end, the bi-racemate is deposited
abundantly in flocks, consisting of minute crystals. We
may collect it on a filter, wash it and dry it.

108 P. C. on the Colours that enter into tfie [Aug.

It is a white powder, having an acidulous taste and red-
dening vegetable blues. Its specific gravity is 2*555. At
the temperature of 55° 100 water dissolve 0*57, and at 108°
1*12 of this salt. When a boiling hot solution is evaporated
slowly the salt is deposited in transparent crystals, but so
irregular that it is next to imp6ssible to determine the
form. Under a powerful microscope some of them appear
six-sided prisms with unequal faces, but the greater number
of them were flat pyramids, seemingly four-sided, with two
very large and two very small faces. Many of them were
grouped in stars composed of very small four-sided prisms.

21*4 grains of crystals of racemic acid mixed with 13
grains of bi-carbonate of potash were totally converted into
bi-racemate. The salt formed weighed 21*9 grains. Now,
had the salt contained (as I intended it to do) exactly 16*5
grains of real racemic acid and 6 of potash, the weight
should have been 22*5. There was a loss of 0*6 grains.
This might have been owing to the paper which covered
the capsule having imbibed a little of the liquid, for it
was spotted the next morning. 22*5 grains of bi-racemate
were exposed for an hour to a heat of 320°. The loss of
weight was 0*0675. From this I conceive that bi-race-
mate of potash is anhydrous.

Bi-tartrate of potash is so well known that no description
of it is necessary. The resemblance of the two salts is strik-
ing. Yet there are several particulars in which they differ.
(To he continued.)

Article III.

On the Number and Character of the Colours that enter into

the Composition of White Light. By P. C.

( Continued from Page 34.^

The simple and satisfactory explanation of the various
appearances of the spectrum in the different stages of its
developement, and the impossibility of accounting for these
appearances with any other arrangement hitherto proposed,
convinced me that the many tints exhibited by nature, must
be derived from the three primary colours of violet, green,
and red, even before this division of the spectrum had been
submitted to the test of experiment.

1835.] Composition of White Light. 109

The observations and experiments which have since con-
firnied these views are so numerous, that there is some
danger of my being tedious, though it is my intention to
select only what I consider necessary to render the proof
satisfactory. In order to avoid this I shall give a preference
to subjects which appear to be capable of deriving improve-
ment from further investigation ; and thus endeavour to
give an interest to the inquiry, where it might otherwise
be deficient of it.

It is evident that if we could ascertain the complemen-
tary colours of the different colours which we suppose to
be primary, it would set the question at rest ; but, simple
as the means are which have been proposed for this pur-
pose, there is a discrepancy in the results hitherto obtained,
which is calculated to weaken our confidence, and to con-
fuse rather than elucidate the point at issue.

The la\Y of accidental colours, is thus stated by Sir
David Brewster, in his Treatise on Optics: — " The acci-
dental colour of any colour in a prismatic spectrum, is that
colour which in the same spectrum is distant from the first
colour, half the length of the spectrum."

In another part of the same work, the following is given
as the results obtained by Fraunhofer, with flint glass ; and
by Newton, with a prism, the composition of which is not
stated.

Newton.

Fraunhofer.

Red . . . 45

m

Orange . . 27

27

Yellow . . 40

27

Green . . 60

46

Blue . . 60

48

Indigo . . 48

47

Violet . . 80

109

360 360

Now, if we take the centre of Newton's red at 23, the
orange 27, the yellow 40, and the green 60, we require,
according to this law, 30 of the blue to make half the
length of the spectrum ; so that if blue be the complemen-
tary colour of red, the law in this instance, which brings
the centres of these two colours to correspond, is correct.

110 p. C. on the Colours t/iat entei' into the [Aug.

If we try the law by the same method in Fraunhofer's
spectrum, we require the whole of the blue and four of the
indigo, before we arrive at the accidental colour of the
central red.

If we now refer to the article on accidental colours, we
shall see that the accidental colour of red is stated to be
bluish green.

By the same law we shall find that the accidental colour
of a great part of the green in both spectra, is in the violet,
and a large portion of the violet of Fraunhofer's spectrum
in the blue ; another portion includes the whole of the
green ; and the remainder the yellow and part of the orange ;
so that all these colours must be complementary to different
parts of it.

It is obvious, therefore, that this law, though favourable
to the theory which requires blue to be the complement of
red, is so much at variance with itself, that its support is
of no value.

If, however, we leave the law and turn to the facts, we
shall find the most ample testimony that the accidental
colour of red, is blue ; of green, crimson ; and of violet,
yellow.

I frequently sit in a room where there is a cabinet piano,
the front of which is covered with crimson silk, and where
there is occasionally introduced a sofa covered with scarlet
moreen. In consequence of these opportunities, the follow-
ing experiments have been so often repeated, that I cannot
be mistaken in the result. The piano is at the end of the
room, and the sofa is generally so placed that I can include
both objects at one view.

When I fix my eyes for about a minute, or even less,
upon the crimson silk, and then turn them to the white
ceiling of the room, the form of the silk is seen of a
distinct green colour, without the least approach to blue-

If I make the experiment with the scarlet moreen, the
accidental colour seen on the ceiling, is an equally decided
blue.

If instead of looking at the ceiling, I merely close my
eyes after looking at the objects, the accidental colours,
seen by the light which passes through the eye-lids, are the
same, but much more vivid ; indeed, when the experiments

I

1836.] Composition of White Light. 1 1 1

are made in this way, the spectra are equal in intensity to
the primary colours.

In the centre of the crimson silk there is a gilt ornament,
which in the accidental spectrum is violet ; the different
shades produced by the folds of the silk are also distinctly
marked.

The crimson moreen is trimmed with black cord, which
in the spectrum, with the eyes closed, appears on the blue
as a pure white. The accidental blue, which is light and
very brilliant, is seen some time before the white makes its
appearance.

When both objects are included in the same view, the
spectrum is formed of blue and green, quite distinct, and
in the proportions in which the primary colours fall on
the eyes.

It is not necessary to direct the attention to the distinct
colours, or part of an object, to obtain a correct spectrum.
I have frequently been struck with the appearance of an
accidental colour, the primary of which, not being very-
conspicuous, had previously escaped my notice.

The following accidental occurrence is a proof that no
attention is required to produce the complementary colours
of objects which fall on the eye. Happening while waiting
in a chapel for the commencement of the service, to sit
with a table before me covered with crimson cloth, my eyes
having been fixed for some time partly on the cloth, and
partly on the pulpit in front of it, I was surprised upon
changing my position to observe that the pulpit, which is
painted to represent oak, appeared of two different colours,
divided from each other by a distinct line of separation,
one green and the other its proper colour. My eyes being
very defective I was at first alarmed, fearing it was the
effect of some additional malady ; but it almost instantly
occurred to me that the green must be the accidental colour
of the crimson cloth ; and, upon repeating the experiment
with attention, I found this to be the case, the slightest
motion of the eye being sufficient to produce a stripe of the
accidental colour.

I observed at the same time that the part of the eye
which had been occupied with the green accidental colour,
when again directed to the cloth, received a much more

112 P. C. on the Colours that enter into the [Aug.

vivid impression from it than the other parts of the eye
which had not been removed from it ; and upon turning
the eyes from one object to the other in rapid succession,
both colours became exalted ; the crimson, though some-
what faded, being thus rendered very brilliant; and its acci-
dental colour, upon the oak ground, became a vivid green.

I have made a great variety of experiments in the manner
before described, with all the different colours, and the
results have invariably confirmed the theory I have ad-
vanced, that red, green, and violet, are primitive colours ;
blue, crimson, and yellow, being complementary to them,
and, of course, compound colours.

Another method by which I have analyzed the colours
of the spectrum, has been to direct the eye when impressed
with a primary colour, to a ground formed by a mixture
of this colour with some other, and thus exhibit the latter
colour only ; proving the compound character of the
coloured ground, and at the same time shewing its com-
ponent principles.

If, when the eye is impressed with red, we look at a
white paper, the accidental colour is blue ; if we substitute
a yellow paper, the accidental colour is changed to green.
If we then impress the eye with green, the accidental colour
on a white ground will be crimson, and upon a yellow
ground red : thus, proving that yellow is a compound of
green and red, by exhibiting its component colours sepa-
rately. Crimson and blue may be analyzed in the same
manner. The colours exhibited in these experiments are
rendered much more vivid by repeatedly directing the eye
to the different objects in succession.

Another method of analyzing compound colours, is to
allow light of two colours to fall upon a ground, also, of
two colours, only one of which corresponds with either of
the colours admitted to it ; the other being, of course, the
complementary colour of both. When, for instance, yellow
light, formed of red and green, is admitted to a blue
ground, it produces a green ; this being the only part of
yellow light which is reflected by a blue ground, or by
objects which appear blue in white light. It is upon this
principle that blue frequently appears green by candle
light ; the violet rays being deficient in this light, it
approaches to yellow.

I

1835.] Composition of White Light. 113

Yellow light may be readily obtained by transmitting
white light through a yellow glass, slightly inclined to
orange, which, though it allows the red and green rays to
pass freely, is nearly opaque to violet light.

There is much greater difficulty in procuring light of
any other two colours, free from the third ; but the same
principle may be traced in a variety of operations in the arts.

It is a common practice with dyers to give a ground to
coarse wool, intended to be dyed blue, by boiling it with
cudbear (prepared, I believe, from a species of lichen)*
which gives it a crimson red colour : this process is
technically called rousing, a corruption probably of rosing,
from its giving a crimson or rosy colour. Now, red being
the complement of blue, this at first sight appears to be a
strange preparation for the purpose of economizing the
indigo, which is its object ; for if pure red and pure blue
were properly proportioned, the result would be white.f
But the red given by cudbear is not pure red, but crimson,
a mixture of red and violet ; and the blue given by indigo
can only be rendered dark by increasing the proportion of
the reflected violet light as compared with the green, its
other constituent principle. The crimson ground, then,
thus produced, will not reflect green, at least in so large a
proportion as it does violet ; and, consequently, the blue
colour is rendered dark, or approaching to violet, with a
comparatively small quantity of the dye. There is no
process in the art of dyeing that without explanation appears
more anomalous, or which when explained is more simple
and beautiful.

The operation we have described may be successfully
imitated by a combination of coloured glasses. If we take
a thin piece of the blue glass of which finger glasses are
made, the colour reflected and transmitted by it appears
blue; of a light shade ; if we add another piece of the same
glass, the colour is darkened, but it requires many thick-
nesses to give it the darkest shade ; at which point nearly

* The Lecanora tartarea. It exists also in Parmelia omphalodes. — Edit.

t There is a striking instance of this in some experiments made by Mr. Delaval.
Purple vegetable colours, reddened by an acid, and then converted to a green by
the gradual addition of an alkali, passed through several intermediate stages, one
of which, upon this principle, was colourless.
VOL. II. I

114 P, C. on the Coloiirs that enter into the [Aug

the whole of the green light is excluded, and both the trans-
mitted and reflected colour approach very nearly to violet.

Now, if we include in the combination a single piece
of the glass, known as violet glass, but which, in fact,
transmits red and violet light in almost equal proportions,
the very same effect will be produced by a much smaller
number of the blue glasses.'^ The object being to exclude
the green light, is accomplished by the interposition of the
violet glass, which admits the violet and red in larger
proportions than the green : and as the blue glass absorbs
the red more readily than it does the green rays, the
absence of the latter colour enables it to produce an equal
effect with a much less depth of the medium. Hence, the
indigo, which represents the blue glass, is economized by
interposing the cudbear, which represents the violet, or
more properly the crimson glass.

A mixture of yellow and crimson, upon the same principle,
produces red.

We may illustrate this by another process in dyeing. The
natural colour of cochineal is a red inclining to crimson ; in
order then to produce scarlet with this dye, a yellow
ground is given, either by the mordant, nitro-muriate of
tin,t alone, or with the addition of weld, or some other
ingredient, depending on the shade required ; the brightest
colour, or that which is farthest removed from the natural
colour of the dye, being that which requires the greatest
depth of yellow.

This process may be imitated by the combination of a
deep crimson (violet) with a yellow glass, such as we
have before described : the former of these glasses excludes
the green, and the latter the violet light ; consequently the
red only is freely admitted : if the green is not intercepted
in an equal degree with the violet, and it requires- a con-

* This may be confirmed by admitting light through an aperture in a card,
with the different glasses placed before it in the manner described in another part
of this paper. With one blue glass the accidental colour is red ; with several of
these glasses, yellow ; with one crimson glass, the accidental colour is green ;
but with the addition oio, single blue glass, it is yellow, quite as free from any red
tint as when three or four of the blue glasses are applied without tlie crimson (or
violet glass.)

t Nitric acid, diluted with water, gives a beautiful yellow to wool, without
any other ingredient.

1835.] Composition of WJiite Light. 115

siderable depth of the crimson glass to effect this, the red
will be more or less inclined to yellow.

In making these and similar experiments, we must
constantly recollect that no colour can be a compound of
more than two of the primitive colours : we must not,
therefore, when, for instance, we add red to blue and
produce violet, suppose that violet is a compound of blue
and red ; the fact is, that in this, and all similar cases, a
colour is discovered which happens to be in excess after the
other colours are exhausted in the formation of white light.
Blues dyed with indigo, always transmit and reflect a larger
portion of violet than of green light ; hence, the peculiar
colour of this dye, which is distinguished by forming a
part of Newton's scale ; and hence, the violet colour which
is discovered when the green and part of the violet are
neutralized by the addition of red. The usual method of
dyeing violet, is to give a light blue ground with indigo,
and then convert the blue to violet, with cochineal or some
other crimson dye. It is remarkable, that the different
simple colours are all produced in the greatest perfection
by a mixture of two compound colours ; thus, crimson and
yellow form scarlet, blue and yellow form green, and blue
and crimson form violet. We have, therefore, just as much
reason to infer, that red is a compound of crimson and yel-
low, and violet a compound of crimson and blue, as that
green is a compound of blue and yellow.

Before I conclude this paper, I wish to say a few words
relating to the theory of accidental colours.

The usual method of obtaining ocular spectra, by impres-
sing the eye with coloured wafers placed upon a white
ground, is well known.

Not being able to produce colours of any great intensity
by this method, I have tried various others, among which
the following has been found both convenient and in-
structive :

In a card, white on one side and black on the other, I
cut an aperture, about the sixteenth of an inch in breadth
and half an inch in length, and place before it coloured
glass or glasses, which transmit light of the colour upon
which I want to make the experiment. I then look at the
aperture, the card being held before a window, until the

I 2

116 P. C. on the Colours that enter into the [Aug.

eye is sufficiently impressed, and upon then turning to a
white object, such as a sheet of white paper, I see the image
of the aperture in the complementary colour.

My principal inducement to make the experiment in this
way was, that it gave me a command of colours which I
had an opportunity of analyzing by other methods, and
some of which I could not readily procure by any other
means. I soon, however, found that it had other advan-
tages, among which was the ready production of more
vivid spectra than those procured by the usual method.

In the course of these experiments, when the white side
of the card was turned towards the eye, I observed the
complementary colours playing about the margin of the
aperture; and having before suspected that this appear-
ance, upon which an eminent philosopher has founded a
new theory of accidental colours, was caused by an invo-
luntary motion of the eye, which must necessarily bring
some of the impressed part of it in the direction of the
white paper, and thus produce the complementary colour,
I varied the experiment, either by moving the card or my
eye, and found that the breadth of the fringe corresponded
with the motion, so that at length it became enlarged to
the full size of the aperture, which was thus faithfully
represented on the card. I perceived that the colours of
the spectra produced in this way were much more vivid
than when they were transferred to a distant object, and
I have since usually adopted this mode of making the ex-
periment.

In order to satisfy myself that this is the true explanation
of the appearance, I turned the black side of the card
towards my eye, and when all the light except that which
passed through the aperture was excluded, by looking
through a tube, the inside of which was blackened, the
complementary colour did not appear on the edges.

If the coloured object be placed on a coloured ground,
the colour seen upon the margin corresponds with the
accidental colour produced by other parts of the same
ground. If, for instance, a red seal is placed upon yellow
paper, the accidental colour seen upon the same paper is a
yellow green, corresponding precisely with the colour upon
the edges, which if the seal is withdrawn appears to form

1835.] Composition of White Light 117

part of it. The motion of the eye, which when the object
is placed upon a white ground, produces the complemen-
tary colour upon the margin, causes the edge of the object
itself to re-assume its usual appearance, and to become even
more vivid than when the eye is first directed to it ; both
the primary and the accidental colour being exalted by an
alternate motion of the eye from one to the other, as we
have remarked in a former experiment.

The production of accidental colours may be accounted
for on principles which are not confined to the sight of the
eye, but which extend to all the other senses. The first
sensation, whether of sight, of taste, of smell, of feeling, or
of hearing, is always the most vivid ; and the impression
gradually declines from its commencement, so that, if long
continued, without intermission,* we at length become
unconscious of its existence.

Another principle, common to all our senses, is, that
when the organs are under the influence of strong impres-
sions, they are rendered incapable of being acted upon by
weaker impressions of the same kind, at least with the usual
effect..

Upon the latter principle, if we go from the open day
light into a room in which there is very little light, upon
our first entrance we cannot even perceive the objects which
surround us, in a short time, however, we discover their
outlines, which are gradually filled up, until at length the
most minute distinctions of form and colour become visible.

In this case, the sensibility of the whole of the retina to
the three colours which form white light, is impaired by
the action of the strong light to which it was previously
exposed, and objects which reflect light of a much lower
intensity, are consequently invisible until the former im-
pression is removed, and the eye assumes a state suitable
to the new circumstances under which it has to perform
its office.

If the light to which the eye was previously exposed had
been of one of the primitive colours only, the objects within
the room would have been immediately visible in the two
other colours, or if its sensibility had been impaired by the

* The motion of the eye-lids enables us to see colours distinctly for a longer
time than ^hen this motion is suspended.

118 P. C on the Colours, ^c. [Aug.

previous action of two of these colours, they would have
been seen in the colour of the third.

In the exhibition of fire-works, for instance, when intense
red light, or any other coloured light, is displayed, surround-
ing objects immediately afterwards, if illuminated with
white light, appear of a colour in which the light previously
exhibited is deficient ; white objects of course assume its
complementary colour.

In order then to account for the phenomena of ocular
spectra, we have only to transfer the case of a general im-
pression, to an impression upon that part of the retina only
which has been subjected to the action of light, of any
particular colour or colours for a sufficient time to impair
its sensibility.

Every ray of light makes an impression upon the retina
independently of every other ray : a correct image of objects
could not be delineated upon any other principle : and
although rays of different colours, when within a certain
distance of each other, produce a sensation compounded of
the whole, and not a distinct sensation for each particular
colour, this sensation is produced by their independent
action ; it is not a mixture of the light, but a mixture of the
sensations, which produces, what appears to be, a simple
impression.

One part of the retina may therefore have its sensibility
impaired without its affecting any other part : and any
part or the whole may be rendered insensible to one colour,
and retain its full power as it relates to others."^

If you think your readers will not be tired of the subject,
I propose to give in another paper, a class of proofs drawn
from quite a different source, which I think will be found
to be of some little importance, independent of their prin-
cipal object. P. C.

To the Editor of the Records of General Science.
June 22nd, 1835.

I inadvertently stated in my former paper that a larger
proportion of red than what is required to form crimson
produces pink, but this is incorrect, pink being a crimson

* I am here speaking of light of ordinary intensity, very strong light, by dis-
organizing the general functions of the eye, would no doubt produce a more
extended influence.

1835.] Spontaneous Combustion. 119

diluted with white light; the colours produced by this
mixture are intermediate shades, approaching to red or
crimson, as the proportion of violet light is lessened or
increased. The accidental colours of these shades of red
are blueish greens, varying with the different proportions ;
and as experiments are seldom made with a pure red,
which, indeed, it would be very difficult to obtain, it is pro-
bable that the accidental colour of red is stated to be blueish
green from its having been produced by colours of this
description.

Article IV.

Instances of Spontaneous Combustion, detailed in a paper read
before the Royal Irish Academy, 2bth May, 1835. By
M. ScANLAN, Esq.*

In the beginning of last March a fire broke out in the
extensive turpentine distillery on Sir John Rogerson's quay,
belonging to Mr. John Fish Murphy, which is separated
from my chemical factory by Windmill Lane. The fire,
which was speedily got under, was confined to a heap of
what is termed, by turpentine distillers, chip cake, and,
from the circumstances under which it occurred, could not
be attributed to any other cause than the act of an incen-
diary, or to the spontaneous ignition of this chip cake.

As spontaneous combustion of this substance had never
occurred before in Mr. Murphy's distillery, nor in that of
his father, an extensive distiller of turpentine, for many
years, at Stratford in Essex, I, at first, doubted that the
fire could have originated in this way; however, on inquiry,
I found his mode of working had been, on this particular
occasion, different from that usually employed in his distil-
lery, and, experiments which he kindly permitted me to
make, have since proved beyond doubt that combustion did
take place spontaneously.

Raw turpentine, as it comes from America, in barrels,
includes a considerable quantity of impurity, consisting
of chips of wood, leaves, and leaf stalks.f It was hitherto

• Communicated by the Author.

t The following extract from the letter of a French turpentine merchant, will
account for the presence of these foreign bodies. To obtain the turpentine " th*
fir timber is chopped about a man's height down its side with an axe, not hand ■

120 Mr. Scanlan^ on [Aug.

the practice, in Mr. Murphy's distillery, as it is in England
to heat the raw turpentine up to a temperature of about 1 80°,
as I found by plunging a thermometer into one of his large
copper pans, and to strain the turpentine, thus liquified,
from the impurities, previously to introducing it into the
still, where it is submitted to distillation in the usual way,
with a portion of water, yielding turpentine oil, which
distils over along with the water and rosin which remains
behind in the still. The chips, when -separated by a wire
strainer, still retain a quantity of adhering turpentine worth
saving, and with this view are transferred to a large close
vat, where they are exposed for some time to the action of
steam furnished by a boiler kept for this purpose, as well
as for steaming the empty barrels, in order to remove any
turpentine that may adhere to them. Still, however, the
chips are a good deal imbued with resinous matter, and in
this state form a loose porous mass, which the turpentine
distiller calls chip cake, a material which is used by the
poor in the neighbourhood as fuel.

As long as the process I have just described w^as pursued,
which is the London mode, and that which produces the
best rosin, no accident occurred from fire in Mr. Murphy's
premises, although I have frequently seen immense heaps
of this chip cake collected together in his yard ; but, on
making trial of a different plan, namely, that practised by
a Dublin distiller, Mr. Price of Lincoln Lane, the accident
in question occurred.

On this occasion, the raw turpentine, together with its
impurities, was put directly into the still,^ along with the
proper quantity of water, and the boiling rosin at the end of
the operation strained from the chips.

The chip cake resulting from a single operation thus
conducted, was laid in a heap outside the still house, at
three o'clock in the afternoon, and at midnight was observed
to be in flames.

In the first mentioned process it is obvious the chips were
never exposed to a higher degree of temperature than 212° ;

deep, and afterwards higher up. The turpentine or rosin pat is scraped up from
the foot of the tree. That which is on the side-wound, when scraped off, is white,
and called galley pot, of which the burning incense is made. It does not yield so
much turpentine spirit as the patJ'^ — Edit.

1835.] Spontaneous Combustion, 121

but in the latter, especially when it is the object of the
manufacturer to make amber rosin, the temperature to
which they are exposed is much higher.

The first experiment I made was on the 16th March. I
found the temperature of the boiling rosin, in the still, to
be 250° when the turpentine oil and water had been distilled
off, the lire just drawn from under the still, and when the
liquid rosin was in the act of being strained from the chips
which were introduced into the still with the turpentine.

I had the whole of the chip cake resulting from this
distillation carried into my own yard, upon a wire screen,
and left in the open air, with a view of watching its progress.

The temperature increased gradually in the centre of the
heap, although externally it became quite cold and brittle.
In four hours, in fact, a thermometer thrust into the centre
of the porous mass indicated a temperature of 400° ; a good
deal of vapour was now given off, and the adhering rosin
in the heated parts began to acquire a high colour ; the
smell could be perceived at a considerable distance from my
premises ; it was a mixed smell of pitch and rosin.

The chip cake, in this experiment, was first exposed to
the air at one o'clock in the afternoon, and, though it rained
during the night, at half-past seven the following morning
it burst into a flame.

In a second experiment, I placed the chip cake in an open
tar barrel, having three holes bored in its bottom, about
two inches diameter each, and it did not take fire till the
expiration of thirty-six hours ; but the temperature of the
mass was lowered by removal from the wire strainer to the
barrel, and besides, I am of opinion the limited access of air
retarded the combustion.

In a third trial which I made, combustion took place in
five hours : but in this experiment the temperature of the
boiling rosin drawn from the still was 260°, and the chip
cake was laid, as in the first experiment, on the wire screen ;
the wind, too, was very high. The screen, in this case, was
raised a few inches from the ground, in order to let the
rosin, as it melted, drip away, which it did in abundance.

It appeared to me as if the porous mass became slowly
red hot, in the centre, like a pyrophorus, and as if the vapour
and gaseous matter arising from the decomposed rosin which

122 Mr. Pritchardf on an Easy Method of [Aug.

lay immediately beneath, were inflamed on coming in contact
with it. I was standing by when it suddenly burst into
flame, and I thought, at the time, had the melted rosin
been permitted to drop into water, or had it fallen to such
a distance as not to be kept liquid by the radiant heat from
the red hot mass above, that there would have been no
flame, but silent combustion.

I have since learned from Mr. Price, in whose distillery
it has always been the practice to put the unstrained turpen-
tine into the still, that he was well aware of the fact which
it is the object of this paper to record, from a fire having
occurred several years ago on his premises, when in the
possession of his predecessor, Mr. James Price, and that,
ever since, they cool down the chip cake, immediately on
removal from the still, with water, and afterwards use it as
fuel under the still.

An instance of spontaneous combustion occurred with my
friend Mr. Philip Coffey, of the Dock Distillery, which
is worth relating while on this subject.

He had made a quantity of the mixture used in theatres
for producing red light, a powder consisting of nitrate of
strontian, sulphur, chlorate of potash, and sulphuret of
antimony, with a little lamp-black. A paper parcel of this
'' red fire, " of about a pound or two by weight, was left by
him on a shelf in a store-room where there was no fire nor
candle light ; the following day, while reading in an adjoin-
ing room, he perceived a smell as if some of this powder
were burning, and, on examination, he found it had ignited
spontaneously on the shelf and was actually consumed.

M. SCANLAN.

Sir John Rogersons Quay, Dublin,
29th June, 1835.

Article V.

On an easy method of measuring Prismatic Spectra. By
Mr. Andrew Pritchard.

It may be questioned whether any important discovery
relating to the prismatic spectrum formed by decomposing

1836.] Measuring Prismatic Spectra. 123

common light, has been announced, since that of its hetero-
geneous nature by the illustrious Newton, with the exception
of the syn chronical detection by Wollaston and Fraunhofer,
of the constant dark lines which were found in every in-
stance, to maintain a fixed and determinate distance from
each other.

The actual measurements and relative extents of the
intervening spaces, may thus be considered^ as important
data; and any contrivance, however simple, for determining
their exact places, will be, it is presumed, acceptable to
the practical observer. I therefore propose to describe a
very facile method of effecting this purpose, prefixing a
brief account of Fraunhofer's telescope for viewing and
examining the spectrum. This telescope has a small achro-
matic object glass, close before which is placed a short
prism, one side of it making a small angle with the axis of
the instrument. For viewing the image a positive eye-
piece is employed, producing a magnifying power of between
twenty and thirty times. In other respects it resembles a
small astronomical telescope, having however a much longer
range of adjustment, so as to render the image of a near
object distinct. Now, the method employed by me of ob-
taining the measurement, consists simply in the addition of
a circular glass micrometer, placed at the focus of the object
glass, it being obvious to every person acquainted with a
telescope, that a series of equal divisions placed in the plane
of the focus of the eye-glass, will measure the relative dis-
tances occurring between the several dark lines in the
spectrum, the places of greatest intensity of the different
tints, or any other phenomena that may present them-
selves. By drawing equi-distant and similar lines upon
paper, the image presented by the spectrum may be laid
down with the greatest accuracy, or indeed when the
colours are sufficiently vivid, they may at once be thrown
on the paper by a camera lucida eye piece.

The micrometers used by me are discs of glass, with from
50 to 100 divisions to the inch, and are similar in construc-
tion to those employed with my microscopes, except in the
omission of the cross lines which are drawn upon the
surface of the latter.

263, Strand, near Temple Bar, June, 1835.

124 Mr. Tomlinsons Experiments and [Aug.

Article VI.

Expei'iments and Observations on Visible Vibration. By

Charles Tomlinson, Esq.

(continued from vol. i.'p. 439. J

60. It is known that during the vibration of a stretched
cord, a series of tones may be heard, together with the
fundamental note, which are called harmonics, from the
circumstance of their forming harmony, and presenting to
the ear a pleasing combination. It has also been generally
understood, in all instruments capable of yielding har-
monics, that these latter decidedly harmonize with another
tone heard at the same time. If this were universally the
case, the term harmonic would be correct ; but having
recently noticed an important exception to the general
system of harmonics, I propose, in the present paper, to
substitute the term secondary tones, instead of the generally
adopted term.

61 . When a musical glass, free from sensible interference,
(12, 49) is vibrated by the moistened finger, a note is pro-
duced which may be termed the fundamental tone of the
glass ; but by varying the force or manner of the pressure
of the finger on the periphery of the glass,"^ one, and even
two secondary tones can be elicited in succession, sometimes
concordant, but generally discordant in reference to the
fundamental note, and to each other. These tones would,
in musical language, be termed harmonics, but, in truth,
harmony is seldom produced. In one instance I have found
the secondary note to be C sharp, which remained always
the same, however the original fundamental note was
lowered by the addition to the glass of water or mercury,
(55, 56). In another instance, three tones were heard, the
lowest of which remained stationary, while the other two
varied according to the quantity of fluid in the goblet ; and
the intervals between the notes have varied from three semi-
tones to nearly, and sometimes beyond, an octave.f Thus,

* The method of doing this I ifind it difficult to describe in writing. It is one
of those habits which practice alone can produce.

t My respected friend, Mr. George Dodd, to whom I am considerably indebted
for kind and valuable assistance in procuring results to be stated in this and one
or two subsequent papers, has, within the last few days, informed me that if an

1835.] Observations on Visible Vibration. 126

it will be seen that the production of the secondary tones
does not depend on the same causes which regulate the
nodal divisions of a string, but on circumstances which I
feel some hesitation in stating, as the real and satisfactory
causes for the production of the above results. Yet, I feel
that if I can only approach to an explanation, something
will be gained ; a small portion of a mystic page of Nature's
exquisite volume may perchance become divested of a small
portion of its obscurity, and, I am sure, that if the theory I
am about to propound be considered untenable, from the
following facts, I will immediately abandon it and seek new
facts to support another theory sufficient to explain the
phenomena of secondary tones, submitting, at the same
time, that the following results (62, 63, 64, 65), are suffici-
ently curious, in themselves, to merit some attention in
connexion with the almost universal phenomena of vibra-
tory action.

62. I have before stated my belief (54) that the active
or positive vibration of a glass goblet is confined to its
interior, the exterior being in a negative or diminished
state of vibration. If one goblet be fixed within a larger
one, so that the latter shall completely contain the former,
and water be placed within and without the interior glass,
and the latter be vibrated, it will be seen that the exterior
undulae are considerably smaller in quantity and extent than
those within. Mercury may be employed with the same,
and even with more satisfactory results, as its great density
allows solids to rest, from its surface, against the exterior
or interior surfaces of the inner vessel, as may be required,
and the vibration or non-vibration of the solid bodies, such
as shots, pieces of iron wire, (fee, will, I think, sufficiently
indicate the positive or negative states of the two surfaces
of the glass.

63. Having poured mercury within and water without
the interior glass, the fundamental note which was originally
(61) D within the stave, was lowered to G within the stave
when the mercury vibrated well ; a shot placed on the
mercury leaning against the interior surface of the inner
glass was violently agitated, (15) and a piece of iron wire

earthenware or porcelain mug, basin, or cup, &c., be placed lightly on the hand,
and the edge struck, two notes will generally be heard, which seldom harmonize,
but have an interval of about one whole tone between them.

126 Mr. Tomlinsoiis Experiments and [Aug.

carried round in a direction contrary to the finger (39).
I then produced the secondary tone C sharp within the
stave, and the mercury, the shots and the wire, were alto-
gether quiescent, while the water without the glass was in
a state of active vibration.

64. It must not be imagined that the secondary tones
are faint and almost inarticulate, nor that they are pro-
duced by partial vibration of the upper edge of the glass
alone ; on the contrary, they are nearly as strong and quite
as clear as the fundamental note of the glass. If the ends
of the fingers be placed on the exterior surface of the glass,
active vibration is immediately appreciated ; whereas, when
the glass yields the fundamental note, the hand may be
placed round the exterior of the glass ^ in any part, or a
cloth may be folded round it without altering the note, or
sensibly diminishing the vibration of a fluid within ; the
clearness of the note, however, is somewhat diminished
(21). The glass may also be filled with water within a
quarter of an inch of the edge, and the fundamental and
secondary tones produced with the same vibrating and non-
vibrating results as respects the fluid or liquid contents of
the vessel : but the terms positive and negative states of
vibration, are, of course, only to be understood in relation
to each other ; for during the production of the fundamental
note, both the interior and exterior of the glass vibrate
and the hand is sensible of the vibration, though I do not
believe the partial vibration of the exterior surface to affect
the production of the real fundamental tone.

65. It will be understood, that in speaking of the funda-
mental tone of a glass, I intend that tone produced under
ordinary circumstances from a musical glass, when mercury
or water, &:c. within such glass vibrates readily. Strictly,
the real fundamental tone is produced when the glass con-
tains only air, and such a tone is superior to any other that
may be produced by the addition of liquids, (51). The
secondary tones can be produced whatever may be the con-
tents of the glass ; and the effect is peculiary novel and
pleasing, when a single glass is employed containing either
mercury, water, or liquids that will vibrate (23), and whose
specific gravity is less than that of water (59). By practice
I have attained considerable facility in bringing out the

• Vide (21.) for " inside " read " outside."

1835.] Observations on Visible Vibration. i'S?

secondary tones, and in passing from them to the funda-
mental, or from the fundamental to the secondary tones
without shifting the finger from the glass. Thus, during
the continuance of the fundamental tone, the mercury or
liquid vibrates readily, and instantaneously becomes quies-
cent during the vibration of the secondary tone, and so on
alternately. I have even produced the fundamental tone
from one semicircle of the glass, and the secondary tone
from the other semicircle, so that during one whole circuit
of the finger round the glass, the contents have been
alternately vibrating and quiescent ; and if the double glass
(62) be employed, the fluids within and without the interior
glass, are alternately in a state of vibration and quiescence
during one whole revolution of the finger.

66, I therefore venture to deduce from the statements
in the foregoing part of this paper, the following propo-
sitions : —

1 . That a series of secondary tones can be produced by the

vibration of a glass goblet^ which tones do not necessarily
harmonize with the fundamental note of the glass.

2. That the interior surface of the glass is in a state of posi-

tive vibration during the production of the fundamental
note, the exterior being negative.

3. That the exterior surface of the glass is in a state of posi-

tive vibration during the production of the secondaiy
tones, the interior being negative.

67. There are few solids in nature incapable of yielding
musical tones. All earthenware and porcelain utensils will
yield such tones by passing the moistened finger round
their edges. I am informed that a musical instrument has
even been constructed and fine tones produced by the vibra-
tion of blocks of granite of peculiar and varying shapes.
I have produced musical notes from lumps of ice, and it is
known that by giving lead a peculiar shape it will elicit a
musical sound. I have procured loud and shrill tones
from watch glasses and from a great variety of plane surfaces
of window glass. Fracture is, I believe, often occasioned
by the efibrts of the glass to vibrate isochronously with an
externally vibrating object. Thus, a thin goblet may be
fractured by the unisonant human voice. The panes of our
windows are constantly undergoing severe discipline from
the action of hail, rain, and wind, from violent opening

12$ Mr, Tomlinsoris Experimeyits and [Aug.

and shutting, and the estimable industry of the housemaid's
love of cleanliness ; all which operations would certainly
throw the glass into a vibratory state, so active, as to induce
fracture were it not that the vibrations are neutralized by
the wooden frame, and to this latter circumstance does the
glass owe its security and we our comfort ; for how incon-
venient would it be if so beautifully available and yet so
fragile an article as glass were to be subject to all the
casualties resulting from brittleness and imperfect elasti-
city! wind, rain, hail, would then compel us to substitute
the opaque and inconvenient defences of our ancestors,
wooden-shutters. I have been tempted into this common-
place digression from the circumstance of having just
knocked from my table on to the floor a valuable astrono-
mical diagram, painted on glass, and bordered with a thin
mahogany frame, sufficient, in this instance, it seems, to
prevent fracture. I now proceed to consider the secondary
tones produced by the vibration of metallic bells.

68. I was anxious to ascertain what relation the secondary
tones of a large bell bore to its fundamental note, and for
this purpose I availed myself of the excellent musical ear
of my friend, Mr. Dodd, during his too short sojourn with
me, and we went accompanied by a flute to the large bell
of Salisbury Cathedral. We arrived at the belfry a few
minutes before six o'clock, when I immediately placed my-
self within the bell, and found that I could stand erect in it
without much inconvenience. A few seconds before striking
I closed my right ear with my right hand, and placed the
points of the fingers of my left hand in contact with the
interior surface of the bell : with the first stroke of the
clapper the effect was somewhat startling and unpleasant,
my left hand and arm became slightly convulsed, and the
sensation was that of handling the poles of a large galvanic
battery ; at the same moment I also experienced a sense of
fulness in the head, and a strong pressure on the tympanum.^

* These sensations may explain somewhat the evidently anxious and uncom-
fortable appearance of some domestic animals, such as cats, dogs, &c., during the
sound of certain notes on musical instruments. I have known pets of this descrip-
tion hurry from the room when music has commenced, and if the door were closed,
I have seen them stand whining for some one to offer them an exit. I am ac-
quainted with one sagacious dog that seldom barks in the drawing-room wherein
an upright piano stands, his bark causing several chords to vibrate sympathetically
to his evident annoyance.

1835.] Observations on Visible Vibration. 12^

These unpleasant sensations were immediately removed by-
withdrawing my hand from the bell, which, so long as I
ceased to touch, I experienced no inconvenience whatever ;
but, on the contrary, a somewhat pleasurable feeling, re-
sulting from an apparent sense of a vast number of notes
rapidly changing, and as rapidly returning to the same
point. The vibration of the bell continued about a minute
and a half after the last stroke, and it was quite evident
that several notes were produced, besides the fundamental
note, which was E flat, within the stave. With the last
stroke the octave notes above and below were heard, and,
as the sound gradually subsided, the third and fifth harmo-
nics were just sensible to the ear. We could not, however,
assure ourselves of the relative values of these notes by
simply listening, but a few minutes after the hour had
struck, we vibrated the bell on various parts of the exterior
surface by means of the knuckle and palm of the hand, the
result being the production of five different tones, all in
perfect harmony with each other, E flat, G, B flat, E flat all
in the same octave, and another E flat, at least, two octaves
below the fundamental note of the bell ; but these different
notes seemed to belong to distinct parts of the bell ; thus,
at the lower edge the fundamental E flat was loudest ; the
other notes were also heard but in a subdued tone; at about
half way up, the G was distinctly brought out, and at the
upper part where the vertical sides merge into the horizontal,
B flat prevailed ; while close upon the axis we distinguished
the upper E flat ; but, in all these instances the major
chords of the octave were perceptible, the only difference
being found in the circumstance, that different notes predo-
minated at different and distinct parts of the bell. We also
found that notes in another key could be produced by
striking the bell at parts away from those at which the
harmonics prevailed ; in this case, single secondary tones
could be produced of an isolated character, vague and in-
distinct, differing in a marked degree from the pleasing
harmonies, as elicited from the four points above described.
69. The foregoing explanation will be better appreciated
by reference to the following figure : —

VOL II.

130

Mr. Tomlinsons Experimenis and [Aug

O

4

„ 4i

13

„ 5^

7

,. 2i

3

„ 3

The figure of the bell represents that of Salisbury Cathe-
dral, the dimensions of which I find to be nearly as follows :—

Feet, Inches,

Diameter

Circumference at bottom .
Circumference at top . .
Depth

1. The fundamental tone, E flat.

2. The third harmonic, G.

3. The fifth, B flat.

4. The octave, E flat.

5. The acute harmonic, E flat.

6. The grave harmonic, E flat.

The average thickness of the vertical parts of the bell
seems to be about three inches and a half, or four inches.

1836.] Observatiom on Visible Vibration, 131

and I should observe, that the existence of the very high E
flat (marked 5) is somewhat doubtful.

70. In a recent visit to London, Mr. Dodd was so kind
as to accompany me to the large hour bell of St. Paul's
Cathedral. Our observations produced similar results, but
the very inconvenient footing among the rafters of the
belfry, the noise of the busy world below, and the great
thickness of the metal (ten inches) all militated against
accurate observations, and differed much from the monastic
stillness of our former serial observatory in the tower of
Salisbury Cathedral. As far as we could perceive, the rela-
tive distinctness of the tones was not much varied by strik-
ing on different parts of the exterior surface ; but the major
third and the major fifth were always perceptible, while
the tone of the grave harmonic was of so vast and splendid
a character* that it was difficult to determine to what octave
it belonged.

71 . We also remarked a curious instance of interference.
When the bell was struck with the palm of the hand
frequently and at regular intervals, one note seemed to
prevail ; but when a sudden blow was given at a smaller
interval of time, the isochronism of the vibrations was dis-
turbed, and the product was a note two whole tones higher
than before.

72. The two smaller bells which chime the quarters have
for their fundamental tones E and A, with the secondary
tones G sharp and B ; and C sharp and E. Immediately
after the quarters have chimed, these bells afford a fine
example of interfering sounds ; the intervals of silence
being well marked and distinct. These intervals cannot,
however, be considered to owe their origin to the causes
before stated (12), but to certain systems of undulating
circles of air, meeting and combining.

* The German student will not fail to remember the immortal production of
Schiller, " Das Lied von der Glocke."

" Von dem Dome,
Schwer und bang,
Tont die Glocke
Grabgesang."

*'■ Vom reinlichen metalle.

Rein und vol! die Stimme schalle.'*

k2

132 Mr, Tomlinsons Experiments and [Aug.

73. The results of these observations on the three bells
of St. Paul's may be thus stated.

Fundamental Tones. Secondary Tones,

Large bell A D. F. sharp A

1st Small bell . . . E G sharp B
2nd Small bell ... A C sharp E

74. From these experiments and observations on bells, I
feel no hesitation in stating the fourth proposition of this
paper.

That during the vibration of a hell, formed of the usual metal,
a series of secondary tones are elicited, which hear a
strict musical relation to the fundamental note.
In stating this proposition, I have purposely omitted
mention of those solitary notes mentioned at the latter
part of (68), being willing to make further experiments
and observations on this point, the only one perhaps that
bears any analogy to the discordant secondary notes of the
glass goblet. I desire also to state that although the subject
of this paper scarcely comes under Visible Vibration, still
I have retained the term, because I have found it con-
venient for the sake of reference to consider this paper as
part of the two preceding. In the subsequent papers the
term visihle will be found more applicable.

75. I cannot better conclude this paper, than by giving
an account of some very singular phenomena noticed, within
the last week or two, by my friend Mr. George Dodd.

Mention has been already made (61, note) of the production
of two tones by the percussion of an earthenware mug, &;c. As
it was thought probable, that friction on the edge had afforded
a similar result, and had been overlooked by me, Mr. Dodd
vibrated a common blue cylindrical cup, and found not only
that two notes, D and E, were produced separately, but that
they each alternated four times during one revolution of the
finger : that is, there were four points during the revolution
where D was produced, and four other points which pro-
duced E. These points were not exactly equi-distant, for
reasons before mentioned (12.), but the alternations were
very distinct. A jug with a lip was next tried, with the
same results, the lip offering no obstruction to the develope-
ment of the tones. On pouring water into these vessels the
notes produced were lower in the scale (54.), and what is

1835.] Observations on Visible Vibration. 133

remarkable, the intervals between the notes were observed
to lessen in proportion as water was added, so that when the
vessel was quite full, the two notes seemed to become uni-
sonant. Tea cups of different dimensions produced similar
results ; but Mr. Dodd was not attended with equal success
when saucers and plates were employed, probably on account
of the difficulty of holding them without disturbing the
vibrations, the former vessels being held by the bottom rim
and not by the handles.

In repeating these experiments I found it necessary, in
order to succeed, to follow Mr. Dodd's directions, and listen
for a *' still small voice, " the sounds produced bearing the
same relation to musical notes as a whisper does to the voice.
The intervals between the notes were never more than three
semi-tones, and can be determined by a tolerably accurate
musical ear. The eight divisions of the rim may likewise
be observed by striking every part of the edge gently with
a quill ; at four points a certain note is heard ; at four^other
points a higher note, and at the intermediate parts both are
heard together : and, indeed, the same will result by striking
either the interior or exterior surfaces, as well as the edge.
In some instances, there was a difference in the strength of
the two notes, which inclined Mr. Dodd to think that one
of them might be analagous to a beat in the intervals of the
other ; but, in general, the notes were so nearly equal in
intensity, that eight vertical nodal lines are supposed to
exist, each of which, separates two vibrating arcs which
produce different notes.

Brown Street, Salisbury, Sth July 1835.

Article VII.

Purification of pyroligneous acid and manufacture of acetate
of lime, according to the method adopted by chemical manu-
facturers. By Chr. Phil. Pruckner, of Hof.''^

Introduction. — From his first connexion with the manu-
facture of pyroligneous acid, which has been on a great
scale, Priickner endeavoured to fall upon the cheapest and
quickest method of purifying it from the foreign matter

* Erdmann und Schweigger-SeideVs Journal fur Praktische Chemie, iv. 21.

134 Ckr. Phil. Pruckner on the [Aug.

with which it is mixed. This object has been further
prosecuted more recently by Dr. Reichenbach, who has
separated several substances which make their appearance
during its purification.

At the time when Priickner first engaged in the manufac-
ture of this acid, these substances were unknown, and conse-
quently his view of the theory of the method of obtaining
it pure, was quite different from that pointed out by Reichen-
bach. Now, however, when we possess an accurate know-
ledge of the products which come over in the purification
viz. Creosote Picamare, Paraffin, <fec., we may expect that
the process about to be described will be improved, so that
the last traces of foreign matter may be entirely removed.
The author considers that the present memoir, will not be
destitute of interest for a considerable period to the practi-
cal chemist, as the process described has been so frequently
repeated and examined, and that the publication will be of
advantage to proprietors and managers of chemical manu-
factories, who may, from the remarks offered, be enabled
to improve the process, by bringing the additional informa-
tion which may be acquired by the consideration of new
discoveries, to bear upon the subject.

Many manufacturing chemists have long been endeavour-
ing to purify pyroligneous acid in different ways. The pro-
cess of Mollerat of Pellerey, who, by the formation of a
great chemical manufactory of this article, not only supplies
it for the use of France, but also exports it, is sufficiently
well known. It consists in forming the acetate of soda by
the double decomposition of acetate of lime and sulphate of
soda ; the acetate of soda being then roasted, the empyreu-
matic matter is driven off and the pure acetate of soda
remains. The objection to the use of this salt is, that at
an elevated temperature it melts, and that the surface of
it gradually becomes dry, while in the interior much water
still exists, and great difficulty is experienced in getting rid
of it, while to the acetate of lime the same objection is not
applicable.

Preparation of the Acetate of Lime. — The crude pyrolig-
neous acid which is distilled from hard species of trees, as
the beech, oak, or alder, or from soft pines, receives a pre-
paratory purification in the following manner : — As much

1835.] Purification of Pyroligneovs Acid^ 6fc. 136

as possible of the oil mixed with tar which swims on the
surface is removed mechanically. This is best effected after
the acid has been allowed to settle for a day. A cask or
large tub, with a double perforated inlaid bottom (einlege-
boden) like the alkaline cask of the soap-boiler, is then
taken and filled to the height of an inch with straw. This
is overlaid by a piece of coarse sack-cloth, which is cut out
in the form of the bottom. Over this is placed six inches
of moist wood sawings, which are pressed down and smoothed
by means of a wooden club. To prevent the sawings from
being displaced and from swimming about, they are covered
to the depth of four inches with a layer of gravel. A certain
quantity of impure acid is then poured into this filtering
apparatus which is termed a filtering cask, and passing-
through is discharged by a cock at the bottom. The tar is
taken up by the gravel. Should the quantity of this be so
great as to obstruct the passage of the acid, the sand may
be stirred up from above with a ladle.

The acid which has thus been filtered is now placed in a
large cast-iron vessel, which is filled up to within ten inches
of the brim. Heat is then applied, and during its action,
lime-water previously passed through a hair seive, to free it
from foreign particles, is added until the acid is neutralized.
The approach to this point may be detected without the
use of litmus paper, merely from the colour of the liquid,
which becomes darker and passes from a blackish brown into
a deep brownish red colour. A great excess of lime is then
added. To a bucket of neutralized acid, containing 120
pounds (115lbs. troy) half a pound, (-479 lbs. troy) is added
in excess. This super-saturation is absolutely necessary ; be-
cause the lime combines with a great quantity of empyreu-
matic rosin and oily matter in the acid, forming insoluble
compounds which are separated first. The next object is
to bring the solution to the boiling point, and to avoid its
boiling over. When a scum appears, the boiling should be
carried on gently, and the matter swimming on the surface
removed, as completely as possible, by means of a ladle during
the whole process of boiling. The solution in this manner
being reduced to one half, is then cooled and clarified in
the cask and allowed to stand for 30 or 48 hours. In this
state it is called the solution of the first boiling.

136 Chr. Phil. Priichner on the [Aug.

To obtain the solution of the second boiling after the
necessary clarification, the liquid is drawn off into the
same vessel after it has been cleaned, or into another iron
vessel of the same description. The sediment is thrown
upon a filtering cloth and set aside. For the second eva-
poration a shallow vessel is employed, whose depth is not
above 14 inches. Priickner uses a vessel of 4 or 5 feet
long and 2 to 3 broad as being most convenient. The fire
burns under it, upon the grate of a wind furnace, and
stretches under the bottom of the vessel towards the chimney.
When the solution of the second boiling is heated, the
free lime must be neutralized with pyroligneous acid as
long as reddened litmus paper is coloured blue. When
evaporated to two-thirds or one-half, the solution may be
freed from any impurities by passing it through a linen
filter, or placing it in a cask and allowing it to cool and
settle.

The liquid having been treated in this way should be
again placed in the flat vessel, and by a gentle heat evapo-
rated to a mass, which while warm, should possess the con-
sistence of thick turpentine, and after cooling should not
stick to the fingers, but should rather crumble down when
pressed. Considerable care is necessary towards the end
of this process. When the solution is beginning to become
thick it must be stirred with a curved iron spatula, of such
a length, that it may extend over the whole vessel, in order
to prevent the salt mass from being burned.

The acetate of lime now half dry, is transferred from the
evaporating vessel to a stone or iron plate, and spread by
means of the spatula to the depth of 2 or 3 inches, for the
purpose of cooling. It should not remain so long as to
attract much moisture, but should speedily be subjected to
the last operation, tne drying and roasting of the salt.

The drying furnace is a simple wind furnace, 7 or 8 feet
long, 4^ to 6 feet broad, built of brick ; at 6 inches above
the ground is the ash-pit, 8 inches broad and 12 inches high,
which is covered with a grate of bricks. The fire-place is
20 inches high and 10 inches broad at the grate ; over it is
an arch of bricks, so that the fire cannot play on and heat
very highly, the iron drying plate lying on the side of the
hearth. The space below the drying plate is separated

1835.] Purification of Pyroligneous Acid, Sec. 137

from the hearth, by a partition of bricks 3 or 4 inches high ;
12 inches above the outlet of the earth there is a layer of
iron bars IJ to 2 feet from each other, and upon these is
deposited the drying plate. This consists of cast-iron \ of
an inch thick, and is formed according to the size of the
furnace. Round the plate the furnace is built up to the
height of 10 inches, on the side of the front wall, leaving
room for doors, which may be calculated at 2J feet. These
doors are two, one above the other, through which the whole
interior of the furnace can be inspected. They are formed
of plate-iron, and have in their middle a sliding door to
admit of the exit of the vapour from the acetate of lime
and of some ventilation. A wall built at the end of the
plate or a clay partition separates the whole of the drying
plate from the chimney. In the walls of the furnace,
iron-bars are fixed, and upon these lies a second drying
plate which covers the drying space. This plate as it does
not come in contact with the fire may consist of good
iron or of clay.

Above this drying space another is formed by means
of the chimney. The heat passes as well under as above
the drying space, and passes into the chimney, which is
situated at the side of the furnace, and can be shut by a
valve. In the drying space the temperature is usually be-
tween 60° and 90° R. (167° to 234^° F.)

Turf forms the best material for fuel as it does not burn
rapidly, and produces a steady and equal temperature.

Drying of the Acetate of Lime. — When the furnace is
thoroughly and equally heated, the flame of the fire is
allowed to subside. If wood is employed as fuel, the sliding
door should be opened at the commencement, in order to
allow the moisture to escape. The salt is transferred from
the evaporating vessel to the drying plate, and spread out
to the depth of two inches ; and, after the first portion has
become somewhat dry, the depth is increased to four or five
inches ; the heat is preserved at the degree already men-
tioned for twenty-four hours, and during this time the salt
is turned several times. Subsequently, when the mass
appears to be becoming dry, the temperature may be in-
creased to 100° (257- F.) so as to dry it completely. The
mass is dry and properly roasted when it possesses the

138 Chr. Phil. Pruckner on the [Aug,

following characters : It must, before cooling, be brittle,
easily crumbled between the fingers, mixed with blackish
carbonaceous points or streaks, between which appear white
pieces of dry salt. A solution of the comminuted salt, in
four or six times its volume of hot water, possesses a yel-
lowish brown colour with a dark tinge, while previously
it had a reddish brown colour.

When the heat is increased towards the end of the pro-
cess, as described, care must be taken to do it gradually,
so that no smoke shall rise from the acetate, because it
might thus be decomposed. Neither must any spark be
permitted to come in contact with the acetate of lime ;
because, like sugar of lead, it possesses the property, in
these circumstances, of catching fire and burning, by which
the whole dry preparation would be completely destroyed.
The treatment of the acetate of lime in this manner, by
means of gradual drying, as experience has shewn, possesses
many advantages over the method of drying the salt in an
open vessel, because there is no loss of acetic acid, as always
occurs by the latter process. The operator has the prepara-
tion completely in his power, and with little expense of
fuel and time, many hundred weights of salt can be pre-
pared at once.

This process does not merely extend to the removal of
the moisture from the acetate of lime, but a chemical in-
fluence is exerted by means of it. Because, it is certain
that the substances formed by dry distillation, which have
been recently distinguished by Reichenbach, are partly
dissipated by the heat, and partly decomposed ; the acetate
of lime possessing very different properties before and
after the process. After the process the salt does not
imbibe water so readily as it did previously. After solution,
filtration and evaporation, a much purer product is ob-
tained than before, and upon the filter a resinous matter
remains, the constituents of which have not yet been ex-
amined. After the completion of the previous steps the
operator proceeds to the next, the

Separation of pure Pyroligneous and Acetic Acid. — Into a
cast iron retort, capable of holding 30 measures of water,
(of 2 lbs. Vienna weight), introduce 20 lbs. (Vienna weight)
of dry acetate of lime, and then 5 lbs. of water, and stir the

1836.] Purification of Pyroligneous Acid, ^c. 139

mixture well up by means of a wooden spatula. This pre-
paration should be made in the evening, and the mixture
allowed to stand till the morning. On the following day
20 lbs. of English sulphuric acid, diluted with 5 lbs. of water
should be added, and the cover of the retort cemented.

The cover should be made of pure tin, and united with a
refrigatory, whose tube is also formed of the same metal.
Priickner considers porcelain preferable to tin for the com-
position of the cover, or rough burned clay (nicht durck-
switzender), the latter of which he himself employs.

To prevent the melting of the tin, when that metal is
employed, it is necessary to separate it from the iron of the
retort by means of a stripe of linen ; a luting of lime and
fine sand then serves to unite the cover and belly of the
retort. Larger retorts are not desirable, because, towards
the end of the distillation, decomposition of the acetic acid
is readily produced, in consequence of the destruction which
a portion of the mass in contact with the bottom undergoes,
while all the acid contained in it is driven off. The distilla-
tion begins with a gentle fire, and should be carried on
without increasing the heat, until the liquid passing over
begins to produce a yellowish colour in the distilled liquid.
It is not worthwhile to obtain the last portions of the acid,
because the educt is impure, and sulphur begins soon to
sublime.

From the 25 lbs. of acetate of lime are obtained 25 to 27
parts of acid. The gypsum remaining in the retort can be
easily removed. It contains some free acid, which may be
washed out and preserved for further use. By the action
of the sulphuric acid upon the acetate of lime, a sulphurous
smell will be perceived, which also exists in the weak acid
which passes over first. This arises from a partial decom-
position of the sulphuric acid, in consequence of which
sulphurous acid is disengaged.

To diminish, as much as possible, the quantity of this in
the whole distilled liquid, the first tenth is removed. The
subsequent distillation is continued until the liquor passing
over begins to lose its pure water colour. The last portions
will, therefore, be separated and mixed with the acid which
passed over first, for the purpose of being further purified.

The acid obtained in the manner described, possesses

140 Chr. Phil. Pruckner on the [Aug.

generally the specific gravity of 1-045-- 1'050, is colourless,
like water, and retains still a trace of the original empyreu-
matic odour.

It contains also some sulphurous acid, and possesses cor-
responding characters, but loses it after being exposed for
some time to the air, in open vessels, the acid being con-
verted into sulphuric acid.

It is obvious, from the quantity of acid recommended,
that, for the decomposition of the acetate of lime, an excess
of sulphuric acid is necessary ; since, for 100 parts of dry
salts, 62 parts of acid, excluding stechiometrical quantities,
would be sufficient. The peculiarity of Priickner's process,
he considers to consist in these proportions ; and he has
found that the addition of the excess of sulphuric acid is the
most powerful method of destroying or decomposing the
empyreumatic matter existing in the pyroligneous acid. In
consequence of inattention to this circumstance, the methods
of purification pointed out by several chemists, especially
that of B. Stolze, in his work, — Griindliche anleitung die
rohe Holzaure zu reinigen," &;c., must be either useless or
very inefficient. The method of previously heating the
acetate of lime, and of abolishing the drying in an open
vessel, over a free fire, is a decided improvement. For thus,
there is an inconsiderable or no loss by the decomposition
of the acetate of lime, with the least possible waste of time
and fuel. For manufacturing purposes, as for making ace-
tate of lead, and acetate of copper, there is no need of
repeated distillation, because the sulphurous and sulphuric
acid can readily be separated in the following manner : A
quantity of liquid dis-acetate of lead is to be prepared, to
about a pound of which the distilled acid is to be added,
until no more precipitate of sulphate of lead falls. The
latter should be collected and weighed. The quantity of
sulphuric acid in a given quantity of the acid, being thus
known, it is easy to calculate how much of the acetate of
lead solution will be required to throw down the whole acid
in the acetic acid. Some sulphate of lead is held in solution,
which is of little consequence in the manufacture of sugar
of lead.

Further purification of the Pyroligneous Acid. — For
chemical and pharmaceutical purposes, it is necessary to

1835.] Purification of Pyroligneous Acid, Sfc. 141

have pure concentrated acetic acid. To accomplish this
the sulphurous acid in the distilled acetic acid should be
digested for a short time with finely pulverized brown-stone,
and a little wood or animal charcoal. One pound of brown-
stone and ^ pound of animal charcoal are sufficient for from
25to361bs. of acid.

The supernatant liquid after the precipitate has been
allowed to subside during 12 hours should be decanted off,
transferred into a retort and rectified by a second distillation
to dryness. The acid passes over pure and colourless, and
destitute of any smell, save of acetic acid, having a specific
gravity of from 1-042 to 1*049, or 7° or 8° by Beck's
areometer, and may be used for all chemical purposes.
According to the custom of the trade, and of the French
manufacturers, a portionof acetic ether may be added to
the acid, by which mixture the smell becomes more pleasant.

Supplement. — According to A. Richter, chemical manu-
facturer at Konigssaal, in Bohemia, with whom Prlickner
corresponded on this subject, it appears, that when the pure
acid, obtained by the process described, is neutralized by
carbonate of potash, and then some strong potash lye is
added, it still retains a yellow colour, from the presence of
an oxydizable body, of which it is difficult to free the acid.
Priickner, during the course of last summer, in his re-
searches, fell upon a method of affecting the separation of
this substance.

Pyroligneous acid is not precipitated by infusion of galls,
and even after some time nothing falls. If however tincture
or infusion of galls be poured into a solution of pyroligneous
acid salt, as of raw acetate of lime (or acetate of potash) a
dark reddish purple precipitate subsides, which contains a
salt of tannic acid. The previously blackish brown liquid
becomes clearer and transparent like Rhenish wine, and
leaves after filtration and evaporation to dryness, by being
placed for several days in a temperature of 70° or 80° R.
(189° or 212° F.) a mass of salt, which, when compared
with the original salt, appears much lighter coloured. If
this is dissolved in water, or if the filtered liquid before
filtration is treated with some animal charcoal, the colour
of the salt becomes still lighter, and the odour is removed.
This salt of lime being diluted with i of sulphuric acid and

142 Amdyses of Books. [Aug.

as much water, after distillation carried nearly to dryness,
and digestion with black oxide of manganese and re-distil-
lation, afforded an acid of the specific gravity 1*060. This
acid when neutralized with a solution of carbonate of potash,
and the addition of some pure colourless potash lye, acquires
no colour, and continued in this state for several weeks.
As the expense of the galls would be considerable, Prlickner
recommends as a substitute, a decoction of oak bark, which
he found to afford a precipitate, or a decoction of the fallen
catkins of the common alder (Alnus glutinosa.)

Article VIII.

ANALYSES OF BOOKS.

I. — Optical Investigations. By G. H.S.Johnson, M.A.,
Queens College, Oxford. Oxford: Talboy's, 1835,
p.p. 44.

II. — Optical Investigations. Caustics. By the same. p.p. 33.

The two tracts above named are remarkable, in several points of
view. In the first place, they are an encouraging specimen of the
increasing attention paid to physical science in the University of
Oxford, where, from a variety of untoward circumstances, (into
which we have not, at present, leisure to enter) it has never flourished
to any extent. In the second place, they are of such a character as
would any where claim for their author, a place in the highest rank
of mathematical talent.

In this brief notice it is not our intention to enter upon a minute
analysis, or to pursue any critical details ; this could hardly be done
in an intelligible way, within a short compass, and we would rather
refer those of our readers who are interested in the subject, to the
original tracts. We will merely state their nature and object.

He first examines the formulae which determine the direction of a
ray of hght after refraction, at a spherical surface. These are inves-
tigated in a very general form, and with express reference to the use
of the negative sign. The author also inquires into the approxima-
tion commonly used, by neglecting certain terms in the expressions,
and distinguishes particularly the value of the terms neglected, which
are shewn, in certain cases, to be so great as to involve serious errors.

The second tract is, perhaps, the most strikingly elegant specimen
of analysis, and discloses a new method of investigating caustics, which
is of considerable generality, and remarkably simple in its application,
some instances of which are given.

On the whole, we earnestly reccommend both tracts to the careful
study of those conversant with mathematical optics : they form an in-
dispensable supplement to all existing treatises.

1835.] Analyses of Books. 143

III. — Colcm-ed Impressions of Engravings, from the Natural
History of Animalcules. By Andrew Pritchard, Esq.
London, 1835.

The figures contained in this little work amount to 301. They are
beautifully executed from steel engravings, and are coloured, in order
to render the internal structure of the infusoria more apparent, as
they appear when fed with coloured substances such as indigo and
carmine. The present publication will be very favourably received,
we have no doubt, by the public, as there is no similar work in
this country, and the scattered foreign ones are expensive, and diffi-
cult of access. In consequence of the coloured plates being thus
published separately, those who possess the work of the author on
the Natural History of Animalcules, with plain impressions, will
not require to re-purchase the letter-press.

The work reflects great credit on the author, and should be pos-
sessed by every naturalist and anatomist.

IV. — On the Action of Voltaic Electricity on Alcohol, Ether
and Aqueous Solutions. By Arthur Connell, Es^., Sec.
(From the Edinburgh Trans. Vol. XIII.J

The object of the researches detailed in the first part of this paper is
to determine the immediate constituents of alcohol and ether. The
author found that when alcohol was acted on by the voltaic agency,
a quantity of hydrogen was evolved at the negative pole, which he
conceives was derived from the water which the alcohol contained.
This result is at variance with that of Dr. Ritchie, who obtained
defiant gas at the negative pole, and who concluded that the alcohol
was then resolved into oletiant gas and water. Mr. Connell explains
the non-appearance of the oxygen of the water at the positive pole
in his experiment, to the absorption by the alcohol. The residual
liquid possessed an ethereal odour, but it was not examined. When
ether was exposed to the same influence no disengagement of gas
ensued. Hence, the author concluded, that it contains no water.
An additional argument adduced by the author in favour of the idea
that it is the water of the alcohol alone which is decomposed by
electricity, is that potash dissolved in it precipitated in proportion to
the evolution of the gas. He further infers from his experiments,
that in the action of electric currents upon the hydrogen acids and
haloid salts, as muriatic hydriodic acids, the chlorides,&c., the de-
composing influence of the electricity is limited to the water contain-
ing these substances in solution, and that if any of the elements of
these compounds were detected after a considerable period of action
at the poles of the battery, the cause is to be attributed to a secondary
influence viz. the reducing action of the elements of the water, set free
by the electric energy. The cause, it is presumed, of his obtaining
this result, which, if meant to apply generally, is opposed to Dr.
Faraday's experiments, is that the electrolytic intensity employed was
not sufficiently great. The various intensities have been already

144 Analyses of Boohs. [Aug.

detailed, and it is unnecessary to say more on the subject here. — ■
(-See Records of General Science, I. 384.)

Ether, he states, only dissolves an insignificant portion of potash.
This however is not consonant with the experiments of Boullay, who
found that it dissolves 4 per cent, of hydrated potash. Now, it is
scarcely possible to believe that any chemist could err so far as this.
This is a question of some importance, because if ether contains an
atom of water, as is commonly believed, then analogy could lead
us to infer that potash would be soluble in it to half the extent,
that alcohol containing two atoms of water, is capable of dissolving
that alkali, or at least that it would dissolve potash in some measure.

The author sums up his experiments by adopting the formulae of
Liebig as expressing the composition of ether and alcohol. But as
he has assumed the exact symbols of the German chemist, without
suiting them to the theory adopted in this country, it may be proper
for the advantage of those who are still disposed to retain the simple
views of British chemists, to observe, that five theories have been pro-
posed for explaining the composition of alcohol and ether.

1. That of Dumas, who supposes that deuto-carbydrogen t or
olefiant gas constitutes a base in organic compounds as ammonia does
among inorganic substances. He considers the atoms, however, to
be four times more numerous 'than the views of British chemists ad-
mit. Thus olefiant gas, according to him, is represented by C^ He,
while we should make the formula C^ H^. Sulphuric ether he
expresses byC^Hs + H^O. That is, it consists of four atoms
deuto-carbydrogen, or olefiant gas + 1 atom of water, and is there-
fore, equivalent to our expression, 4CSH2-f HO, or rather,

2 C^ H* 4- H 0,in consonance with Dr. Thomson's theory. Alcohol
is then C^Hs -f-H^O^, or according to our symbols, 4C2 H2 -j-
H2 02 or 4 C2 H2 + 2 Aq.

2. Dumas and Boullay have presented another theory to chemists.
The constitutents of ether, according to the best experiments, exist in
that liquid in the proportion to form one atom of deuto-carbydrogen
and one of water. It is, however, more probable, that the carby-
drogen is double this quantity, but for the sake of simplicity, we
take it as here expressed. The constitutents are, therefore, 2 C +,

3 H + O, as represented by the elementary formula. Now, it is
obvious, that ^we may view these elements either as combined,
according to the previous theory, or we may consider all the hy-
drogen as combined with the carbon, constituting a base, to which the
oxygen is united so as to form an oxide. The theoretical symbol would
then be C2 H^ O, or according to Dumas, C8 Hio Q the radicle
being C^ Hi «. Alcohol would then be a hydrate of this oxide, or
Cs H^o O -j- H2 O, the hydrogen of what is generally considered
one of the atoms of water being combined with the carbon.

* Some have termed the compound of 1 carbon 4- 1 hydrogen, hydro-carbon.
The frequent occurrence of this compound and its multiples, renders it necessary
that a convenient name should be employed. Perhaj^s that adopted in the text
which is essentially the same as that used in the " Inorganic Chemistry " possesses
this requisite.

1835.] Scientific Intelligence. 145

3. Berzelius has recently revived this hypothesis and carried it
further. Alcohol he considers as an oxide and not a hydrate of a
distinct combination of carbon and hydrogen, represented by C^ H^
O. The equivalent symbol for this^, according to British views, is
C2 H'^ O. Ether he represents by the formula C* Hio + 0,virhich
is equivalent to our expression C* H^ -f O ; so that the bases are
different in these two compounds. This view of the composition of
alcohol taken by Berzelius, is rejected by Dumas, on the ground
that if it were correct, sulphovinic acid would be a neutral body, and
the sulphovinates would be sesquibasic salts, which can scarcely be
admitted, when we know that the former is a powerful acid, and the
salts are perfectly neutral.

4. Liebig considers ether as the first oxide of a compound radicle,
for which he employs the symbol C* Hi o. Now, this is obviously
equivalent in the views of British chemists to C^ H^, because we
hold that water is composed of equal atoms of hydrogen and oxygen.
Ether therefore is represented, according to Liebig, by C^ H^^^ O
= C^ H5 O. This is the same view as that taken by Berzelius.
But instead of considering alcohol as an oxide of a different base, he
calls it a hydrate of ether = C^ Rio O + HO or C* H^ O -|-
HO. It is obvious that these two theories are modifications of that
of Dumas.

5. Dr. Thomson considers the bases of ether and alcohol to be dif-
ferent, the elements being present in the same proportions, but are
double in the former. The base of ether is tetarto-carbydrogen, and
that of alcohol deuto-carbydrogen. Their expressions are ether C* H*
-f Aq., alcohol C2 H2 _j_ 2 Aq. The simplicity of this view, and

its consonance with experiment, so far as we at present know, (the
bases described by Liebig and Berzelius having never been obtained
in a separate state,) favour its adoption, until further researches com-
pel us to have recourse to another theory.

Article IX.

Scientific Intelligence.

L — Proceedings of the Ashmolean Society of Oxford.

March 27, 1835. — Dr. Daubeny proceeded to deliver a commu-
nication on Vesuvius, and the nature of volcanic agency.

He began by giving a brief account of the great eruption of Vesu-
vius which occurred in the month of August of last year, and which
had been preceded by a series of ejections of stone and scoriae from
the crater, continuing at intervals ever since the year 1831.

These ejections had by degrees occasioned the formation of two
conical hillocks within the area of the crater, the most considerable
of which, just before the breaking out of the eruption of August, was
more than 200 feet in height. Both the above, however, disappeared
at an early period in the course of the eruption, having been swallowed
up within the mountain during the course of a single night.

The lava which first burst forth took the direction of Portici, but
this stream proceeded but a short way down the flanks of the moun-

VOL. II. L

146 Scientific Intelligence. [Aug.

tain, owing to the breaking out of a more considerable current on the
opposite side of the mountain.

This latter took the direction of the township of Ottayano, sweep-
ing away in its course several small villages, and about 180 houses.

The lava when visited by Dr. Daubeny even so late as the end of
December, or four months after the time of its emission, still
possessed a high temperature, and was exhaling much steam, free
muriatic acid, and sal-ammoniac ; which latter appears from former
observations to be a common product of volcanic action.

It remains to be explained, first, how this and other volatile
matter can remain for so long a time pent up within the substance of
the heated mass ; secondly, how this salt was in the first instance
generated in the bowels of the earth.

The first question may perhaps be answered by supposing the
body, whilst within the mountain, to have been entangled in the
lava, and there to have been confined by the enormous pressure of
the superincumbent mass ; so that when the eruption took place,
the volatile matter did not at once find the means of escape, but
continued in part locked up within the pores of the viscous mass.

The second question requires for its answer a consideration of the
causes of volcanic action in general.

The president brought forward some facts and authorities bearing
on the question whether Pompeii was destroyed by the eruption of
A. D. 79.

That Herculaneum and Pompeii suffered from an earthquake in
A. D. 62 or 63, appears from Tacitus Ann. XV. 22. and Seneca
Nat. Quaest. VI. 1.

Pliny in mentioning the eruption says nothing of these cities.

Tacitus speaks of some cities being destroyed during the reign of
Titus A. D. 79-81. s y & B

Dio Cassius (in A. D. 229) expressly says, that Herculaneum and
Pompeii were destroyed by an eruption in the reign of Titus
(LXVI. 23.)

From Statins (A. D 95) it would seem they were not wholltf
destroyed. Florus (A. D. 116—120) mentions them as still existing.

M. Aurelius, however, mentions them as entirely destroyed before
A. D. 161 (IV. 18) ; as alsd TertuUian (Apol. 40) in A. D. 200.

Some further discussion took place: and Mr. Twiss mentioned,
as a well ascertained fact, that Stromboli is always active when the
Sirocco blows, but at no other time.

Mat/ I5th. — A paper was read by the Rev. R. Hussey of Ch.
Ch. on the standard and value of some ancient coins.

After some account of the experiments hitherto made for finding
the standard of the silver of the ancient currencies, the results of
assays of some coins were reported, and the value of them calculated.
From the analysis of a quinarius of Rome in the time of the consul-
ship, the value of the denarius of 60 grains weight, compared with
our silver currency, was computed to be nearly Sf^/. The Attic
drachma of 66^ grains weight was computed, from the assay of
three drachmffi of different ages, to have been from 9Jf/. to 9^.4 in

1835.] Scientific Intelligence. 147

our silver ; and that of Corinth, or Syracuse, from the analysis of a
didrachma of that coinage, to have been about equal to the lowest
value of the Attic. The Attic currency was shewn to have been
at one time of a little lower standard than it was afterwards raised
to, and then again to have been much depreciated, till it was less
fine than the average standard of Greek silver, and the early Roman.
And it was inferred that, although the ancient money was generally
of a very high standard of fineness, the alloy found in it was pur-
posely mixed, and not owing only, to want of skill in refining.

Mr. Powell, on presenting a copy of his paper from the Journal
of Science, entitled " An Abstract of M. Cauchy's Theory of Undu-
lations, leading to an explanation of the dispersion of light, &c., made
a few remarks on the nature of the results he had recently obtained,
and which will appear in the next part of the Philos. Transactions.
In a former communication (see Records of General Science, I. 463)
he had explained generally the state of the question at issue ; and
now proceeded more particularly to refer to the nature of the spectra
formed in the very remarkable experiment of M. Fraunhofer, by
covering the object glass of a telescope with a fine grating of parallel
threads, and viewing through it a narrow line of light parallel to the
threads. The appearance is that of the image of the line colourless
in the centre, and a spectrum or coloured image of it on each side.
In these spectra the colours are perfectly pure. They are produced
simply by the interferences of the rays passing the grating, which
give bright and dark spaces, at different intervals, for the different
rays ; and at such intervals as allows the points of brightness for the
red, yellow, green, &c. to succeed one another in such a manner as
to give a very complete insulation of each coloured ray in a state of
great purity. Professor Airy considers this as the natural, or
standard, spectrum ; from which those formed by prismatic refraction
deviate in difi^erent ways, according to their peculiarities of dispersive
character. The intervals between successive definite rays in the
interference spectrum are precisely proportional to the differences of
the lengths of their waves, or periods.

It is by means of the data derived from these spectra by M.
Fraunhofer, as compared with those of the refraction-spectra, that
the results of the author's calculations have been obtained. By his
extremely perfect apparatus M. Fraunhofer was able to obtain these
spectra in such a state of purity that the dark lines were visible.
Thus, by accurate micrometric measurement, he determined the
lengths of the waves for each of the rays defined by the dark lines.
These values are given in Sir J. Herschel's treatise on Light, art. 751.

M. Cauchy's theory gives rise to the establishment of a relation
between the length of a wave and the velocity of its propagation.
On the ordinary theory no such relation subsists : and by conse-
quence, rays whose waves are of all lengths ought to be refracted
alike. Thus M. Cauchy's theory assigns an explanation of the un-
equal refrangibility. From his memoirs, the author has deduced a
formula expressing the precise nature of this relation. On any
theory of undulations the velocity is the reciprocal of the refractive
index. In this point of view the formula deduced from the theory
(which ought to give the value of the refractive index (^) for a ray

l2

148 Scientific Intelligence. [Aug.

whose period or wave is (\) involving certain constant quantities
dependent on the nature of the prismatic medium, H, r, n, and tt
the semi-circumference) is this :

By substituting Fraunhofer's values of X from the interference
spectra, the values of jj, for the same rays were calculated, and com-
pared with the refractive indices determined also with the utmost
accuracy by Fraunhofer for the same rays, in prisms of ten different
substances ; viz. . four kinds of flint glass, three of crown glass, water,
solution of potash, and oil of turpentine. These calculations gave
an accordance in every instance exact to three places of decimals.
And this will be allowed to afford a complete verification of the
theory for all the cases examined. These in fact constitute all the
instances in which exact determinations have yet been made. The
author is therefore now engaged in endeavouring to extend the
series to a larger range of media. For this purpose it will be neces-
sary to form prisms of a variety of solid and liquid media, and con-
siderable difficulty may arise from not being able to get them
sufficiently pure and homogeneous to shew the lines.

Again, the calculations present considerable difficulty ; especially
in finding a series of arcs, which shall fulfil the twofold condition of
being themselves in the ratio of the values of X, while they are to
their sines as those of ^. This problem has been facilitated by a
remarkable elegant geometrical construction, communicated to the
author by the Rev. A. Neate, M.A., of Trinity College.

Even without reference to the tlieory of undulations, any formula,
were it but empirical, would in the present stage of the inquiry be
valuable, if it afforded an accurate representation of the facts. In
this point of view, then, the formula here employed may be regarded
as not unimportant, if it merely express the numerical law of dis-
persion for the substances examined.

Ma;/ 29th, 1835.— A paper was read by the Rev. R. W. Browne,
M. A., St. John's College, on Halley's comet.

The following are the recorded appearances of this comet. We
repeat this because some of the figures in our report of Dr. Lardner's
lecture are inaccurately printed. (See Vol. I. 467.)

1. B. C. 130, birth of Mithridates.

2. A. D. 323, after six revolutions.

3. „ 379, see Lubienietski in Theatr. Com.

4. „ 550, Rome taken by Totila the Goth.

5. „ 1005, no remarkable event. After five revolutions.

6. „ 1230, idem. After three revolutions.

7. „ 1305, the plague.

8. , 1456, Pope Calixtus II. Mahomet II. took Constantinople.
According to theory as well as history the magnitude and brilliance
of the comet were then at their maximum.

9. „ 1531, observed by Apian of Ingoldstadt.

1835.] Scientific Intelligence. 149

10. „ 1607, observed by Kepler and Longoraontanus, Sept. 26.

11. „ 1682, observed by Halley, who predicted its return in 1758.

12. ,, 1758, returned as predicted, and discovered by Palitzch,
December 25. Observed by Messier and De L'Isle in January,
1 759. Arrived at its perihelion, March, 1 759.

Mr. Twiss gave a short account of the papyri from Herculaneum
preserved in the Museum at Naples, and of the method of unrolling
them.

They were first discovered in 1753, and are now deposited in the
Museo Borbonico. Being rolled up in scrolls, they have the appear-
ance of pieces of charcoal : and being piled up, it was only by acci-
dent that attention was directed to them, when Greek and Latin
characters were seen upon them. They are found reduced to a
scorched state, not more substantial than tinder. The difficulty of
unrolling them has been overcome by attaching to the back some
gold beater's skin by a strong gum : a small portion of this (when
fixed) is then gradually unrolled by bands attached to it, the scroll
resting in a semi-cylindrical trough lined with cotton. The process
can only go on at the rate of about one inch per day. Several
volumes have been restored and published. They appear to be chiefly
works of Epicurean philosophy. On the authority of one of them
the Economics of Aristotle is decidedly ascribed to Theophrastus.
The majority are Greek. One contains a review of the Iliad, in
which the heroes of Homer are considered as all allegorical. The
Latin works are on a differently prepared and thicker papyrus. The
name of the author never occurs till the end ; hence the impossibility
of ascertaining what they are till completely unrolled.

Some remarks were made on the share which Sir H. Davy had in
suggesting the plan of unrolling, and conducting the whole research,
as described in his paper in the Philos. Trans. 1821.

June \2lh. — An anonymous paper was read, entitled, '' A few
remarks on the theory of Volcanoes."

The author's principal object in this paper is to support the theory
advanced by the late Dr. E. D. Clarke.

Dr. Daubeny made some remarks on this paper, which he con-
sidered to accord with his own theory, as far as it goes. But it does
not proceed to account for ihe evolution of hydrogen, which he
explains by the action of water on the metallic bases of the earths.
The part of Dr. Clarke's view most open to doubt is the degree of
intensity of fusion, of which no sufficient evidence is adduced.

Dr. Daubeny then referred to the subject of his own paper on the
absorption, &c. of plants. He had tried experiments in which plants
were deprived as much as possible of access to calcareous matter, in
which case the quantity of it found in their ashes was diminished,
but still some appeared. This might be derived from the water, or
even the atmosphere. He stated that when strontian was substituted
for lime, the same deficiency of calcareous matter was observed in
the plant, shewing that vegetables exercise a kind of selection as to
the earthy matter they secrete.

Analogous experiments were mentioned on hens, who, when de-

150 Scientific Intelligence. [Aug.

prived of access to any other earth except strontian, after a time
began to lay eggs destitute of an earthy shell.

The origin of phosphoric acid was also noticed; this may be sus-
pected to be an organic product.

Mr. Tvviss made some remarks on the papyri, especially with
regard to the claims of the Padre Anto^. Piaggio to inventing the
mode of unrolling them. These he considered well founded, and
that Sir H. Davy only improved upon the process by suggesting the
use of alcohol to soften the rolls. They were sometimes soaked in
ether. The ink is made of carbon mixed with some glutinous matter :
hence probably the ammonia, sometimes found to be present. It is a
question whether the papyri were actually carbonized by the action
of fire. Sir H. Davy supposed it the effect of hot water.

Dr. Daubeny observed that long continued moisture alone would
suffice to carbonize and blacken a vegetable substance.

Mr. Powell made some remarks on the recent researches of
M. Melloni on radiant heat, of the second portion of whose Memoir
he has recently received a copy. He referred more particularly to one
point, viz. the repetition of his own experiment by Melloni, with his
extremely delicate apparatus, and fully verifying his results. But
M. JMelloni appears to view the subject under a different aspect, and
to adopt a different theory. This renders the confirmation of the
fact the more satisfactory.

If the experiment be substantial, it appears to the author that his
conclusion follows by necessary consequence. M. Melloni adopts
the theory that the heat by passing through the glass screen
acquires a new property, or new relation to the surfaces of bodies on
which it acts ; an hypothesis which is at variance with all analogy.

In the Philos. Trans. 1825, the author's paper appeared, in which
he maintained (in opposition to the theory of De La Roche) that
from a luminous hot body there emanate at the same time two dis-
tinct sorts, or causes, of heat, distinguished by different properties.

This was evinced by experiments, in which the ratio of the effects
on two thermometers, one coated with a black, the other with a
white substance, (but very absorptive for simple heat,) was observed
first with, and then without, the interposition of a glass screen. With
the screen the absolute effects were of course diminished : but the
remarkable circumstance was, they were in a different ratio.

Of the accuracy of this experiment, it would seem that some doubt
must have existed in the minds of those writers who have since treated
the subject, since they either omit to refer to it, or, what is more
extraordinary, adopt it along with the theory which it contradicts.

It is possible that the nature of the reasoning may have been mis-
understood, from having been too briefly stated. It may perhaps
appear more distinctly if repeated thus algebraically : —

Let the effects of a luminous hot body on the black and white
thermometers respectively be,

without a screen h w

with a glass screen .... 6^ w^y
Now, by observation, we know the ratios in these two cases, and we

1833.] Scientijic Intelligence. 151

always find the ratio — >

w w

Hence, we know also the ratio of the portion of the effects intercepted

, . , . b—h^

which IS

w — w^

By the principles of ratios we must therefore have — > — — —

w^ w — w^
Or, in other words, the portion of the heat which passes the screen
affects the black and white surfaces in a different ratio from that
portion which is intercepted. The two portions are thus clearly
distinguished by different properties. Or, in other words, the whole
effect is due to two distinct causes acting simultaneously ; in which
the transmissibility or otherwise is invariably accompanied by the
particular relation to surfaces. The one species agreeing in these
properties with the solar rays, the other with the heat from non-
luminous sources.

M. Melloni failed, like the author, in his attempts to polarize
simple heat. But many of his experiments, and especially this,
have been since repeated by Prof. Forbes of Edinburgh, who has
succeeded in establishing the polarization, both by transmission
through tourmaline and piles of mica, and by reflection, most de-
cisively in the heat from luminous sources, and from non-luminous
also ; though he allows that in this last case the effect was extremely
small. He has also followed out the subject into numerous important
consequences. (See Edinb. Trans, vol. xiii.) The distinction de-
duced from the experiments of the author (above referred to) must
however affect the entire serieis of results relative both to polarization
and transmission.

II. — Application of Hot Air in the smelting of Iron.

This important improvement is now generally appreciated. At the
smelting furnace of Plons in Wurtemberg, before employing the
hot air the consumption was 100 kils (2J cwts.) of ore, 40 cubic feet
(48i) of charcoal, and the produce under the old system was 3,000
kils, (3 '58 tons) while with the hot air it is on an average 3,750
kils, (4*48 tons.) At Koningsbronn, in the same kingdom, to ob-
tain 108 livres (1*17 cwts.) of bar iron with cold air, it required 20
cubic feet (24*2 Eng. c. f.) and with hot air only 17 cubic feet,
(20i). {Ann, des Mines, vi. 464.)

The temperature to which the air is raised, is however much
inferior to the lowest standard in this country, for at Plons, accord-
ing to Berthier, the temperature of the heated air is only 150'' or
200", (302°, 392 ' F.) while at the Clyde iron works, the usual test
of the standard temperature is the melting point of lead, or 006° F.
This is the lowest point to which the heat is allowed to fall, for it
may in general be much higher. Yet even with this disadvantage
in Germany, we see that the expenditure of the combustible matter,
has been reduced one-fourth, with a sensible increase of the product.

t5*2 Scientific Intelligence. [Aug.

The effect of the heated air has commonly l)een attributed to the
absence of the cooling power, which was exercised by the cold air
on its being introduced in contact with the heated contents of the
furnace. Berthier denies that this is the mode in which it operates.
He thinks that the phenomena which result from the employment of
hot air proceed from the greater activity of the combustion in the fur-
nace, than when the air has not been previously heated, that is to say,
that with the same weight of air there is more oxygen absorbed in
the first case than in the second. If this opinion is correct, it follows,
that less hot air will be required than of cold air for the combustion
of an equal quantity of charcoal in the furnace, and that the air
which proceeds from the latter being possessed of little oxygen, can-
not support combustion. Now, the exhaustion of the oxygen in the
air is a point of essential importance, when we wish to obtain a very
strong heat, for the azote of the air only assists in producing a loss
of the portion of the heat developed by combustion. Hence, the
less air that is consumed the less does this cause of cooling operate.
Besides, the affinity of gas for solid substances is increased by the
heating of the gas.

It has been said that effects similar to those produced by heated
air, may be obtained by the employment of cold air sufficiently com-
pressed, or what would be extremely powerful, the use of hot air
compressed to such a degree as experience might point out.

III. — Action of Muriate of Ammonia upon some Sulphates,
and upon Silver.

M. VoGEL has found that the sulphates of iron, copper, and man-
ganese, are partly decomposed by a solution of sal-ammoniac. This
action produces two double salts, the one which crystallizes first is
the sulphate of ammonia and metal, the other more soluble is the
muriate of ammonia and metal.

2. Sulphate of lime is more soluble in water charged with muriate
of ammonia than in pure water, but it is not decomposed by this
salt, and the sulphate of barytes is not soluble in a solution of this
salt.

3. Sulphate of lead is completely decomposed by a solution of
sal-ammoniac, from which result muriate of lead and sulphate of
ammonia.

4. A solution of sal-ammoniac acts upon silver with the assistance
of the air and dissolves it.

5. A concentrated solution of sal-ammoniac may dissolve a notable
quantity of chloride of silver, of which the greater part is precipitated
by water.

6. Chloride of silver is still more soluble in a boiling solution of
sal-ammoniac.

7- The vapour of sal-ammoniac carried over pure silver heated
to the temperature at which glass softens, disengages ammoniacal
gas. — (Jonrn. de Pharm. xx. 514.^

1835.] Scientific Intelligence. 153'

IV. — Phosphate of Quinine.

Phosphoiuc acid bearing a nearer relation to the animal economy than
sulphuric acid, Professor Harles proposes to substitute the phosphate
for the sulphate of quinine in medicine ( Pharm. Zeit.) The method
which he described for forming it is considered imperfect by Winkler,
who recommends the following: — He first prepares a muriate of
quinine, by decomposing the sulphate with chloride of barium ;
1,200 parts of the latter are triturated with 480 parts of crystallized
sulphate of quinine. This mixture is then added to 8 parts by
weight of distilled water. The liquid is filtered and the residue
washed. The liquors are united and diluted with 4 times their
weight of distilled water. A solution of phosphate of ammonia is
then carefully added. The precipitate should be washed with cold
distilled water and dried at a gentle heat ; an excess of phosphate of
ammonia should be avoided, because it dissolves the phosphate of
quinine ; 60 parts of muriate of quinine afford 46 of phosphate. It
is a fine crystallized powder, very light, white, and very bitter.
When a solution of it in boiling water is cooled, it is deposited in
silky needles. It is soluble in 480 parts of cold and 140 of boiling
water. It consists of quinine 87*03, phosphoric acid 12-97. Wink-
ler has since stated that it may be formed by the mutual action of
sulphate of quinine and sulphate of ammonia. — {Buchner's Repertor
and Journ. de Chim. Medic, i. 368.

V. — Pectic Acid.

M. SiMONiN of Nancy has given an improved method of preparing
this acid. The pectine and jelly which are formed by the mixture of
the juice of the gooseberries with that of sour cherries, is to be
separated from the liquid part and well washed, to separate the
colouring matter. It is then boiled with a small quantity of weak
caustic potash. The liquid which contains pectate of potash is then
passed through a cloth filter. The pectate is decomposed by agita-
tion with chloride of lime. Decolouration quickly takes place, and
white flocks of pectate of lime separate. These are collected on a
filter and treated with water acidulated with muriatic acid, which de-
composes it and dissolves the lime. The pectic acid is allowed to
drop upon a cloth, and is well washed with water in order to take
up all the muriate of lime and acid which it retains. In this state
pectic acid is almost colourless, in the form of a compact jelly. It
combines with the greatest ease with alkalies. A few drops of
ammonia liquify it and give it a brown colour. If we wish to pre-
pare pectate of ammonia, a sufficient quantity of this alkali is added
to give it the consistence of syrup, which is filtered. It is then dried
in porcelain vessels, where it separates into brown glassy plates. It
is soluble in water from which alcohol and sugar separate the pectic
acid in the form of a jelly.

It is necessary in washing the pectic acid to employ water con-
taining neither lime nor calcareous salts, because the pressure of the
smallest portion of these substances will occasion the production of

i^-1 Scientific Intelligence. [Aug.

pectate of lime, and prevent success. Two hundred pounds weight
of red gooseberries afford nearly 8 ounces of pectate of ammonia,
giving a gelatinous consistence to 500 times its weight of water. —
(Journ. de Pharm. xx.J

VI. — Cases of Poisoning in France.
The number of cases of poisoning in relation to the poisons em-
ployed, are as follows, in the space of 7 years :

1. Of 273 persons accused of the crime of poisoning, 1 71 have
been acquitted and 102 condemned. Of 94 cases reported in the
Gazette des Tribunaux, 54 were produced by arsenious acid, 7
verdigris, 5 powder of cartharides, 5 corrosive sublimate, 4 nux
vomica, 3 fly powder, consisting of impure pulverized arsenic called *
also coholty 2 nitric acid, and single cases by sulphuret of arsenic,
emetic, opium, acetate of lead, ceruse, sulphuric acid, sulphate of
zinc, mercurial ointment, and 5 by undescribed poisons.

2. The causes which produced the crimes have been interested
motives in 28 cases, in 24 lewdness, 15 revenge, 10 jealousy, 6 mad-
ness. Of 8 1 cases the poison was administered, in 34 cases in soup,
8 in milk, 7 in flour, 7 in wine, 8 in bread, 5 in pies, 4 in chocolate,
4 in medicines, 2 immediately by the mouth, 2 in coffee, 1 in cyder,
1 in poultry.

3. Of 94 cases, 60 of the accused persons were males, 34 females.
In order to diminish the number of these cases, or if possible to

destroy the practice of poisoning altogether, it has been propgsed by
M. Brard to colour arsenic with Prussian blue in the proportion of
10 per cent. The propriety of this method is supported by the fact,
that by far the majority of cases of poisoning are produced by colour-
less poisons, arsenic in particular, and several persons have been
prevented from suffering death by poison, in consequence of coloured
substances having been employed for that purpose.

VII. — Dilatation of the Metals hy Heat.

The base for the trigonometrical survey in India was measured by
metallic compensation bars, 10 feet in length, and to prevent any mis-
take an iron standard bar was sent from England, upon which was
marked at a certain temperature the legal English scale. The compari-
son, however, of the standard, with the bars employed, was made at
a different temperature from that at which the former had been
measured, and it was therefore necessary to allow for the dilatation.
Mr. Prinsep effected this by heating the metal uniformly to the tem-
perature of boiling water by means of vapour, and the expansion was
determined by a micrometer formed on the principle of Troughton's
microscope. A double cylindrical tube, 9 feet 11 inches long, and 4
wide, was formed, the interior cylinder being made of copper, and
the external of white iron. The space between the two tubes was
shut at the two extremities by perforated disks, so as to permit of the
insertion of the standard bar in the interior tube. It was supported
by two brass rollers. The tubes were perforated at 4 points for the

1835.] Scientific Intelligence. 165

insertion of the thermometers, the bulbs of two of which rested in
two cavities made in the standard bar. The vapour supplied from a
small vessel entered by a tube at one extremity and passed out freely
by the other end.

The two micrometers were fixed by a vice to two solid isolated
blocks of stone placed at a convenient distance. Mr. Prinsep did not
confine his experiments to iron, but he took advantage of this oppor-
tunity to determine the dilatations of some other metals. The dila-
tation for the first thermic unit, that is, from 32° to 21 2°, he found :—
r Standard bar of 10 feet for the trigo- ^

T 1 nometrical survey I'00l213r , /xj^.oic

^^°"- ^Bar of iron of Indian manufacture . 1-001210? '''''^^^

(Rod of iron 25 feet long 1-001256)

Gold nearly pure 10 feet long 1*001438

Silver containing -\ of alloy 10 feet long . . 1-001904

Copper in plates re-roasted 1*001691

Brass rod of 25 feet re-roasted 1*001906

Lead tube 25 feet long 1 inch in diameter . . 1*002954*

VIII. — Aldeide, and a New Acid.

LiEBiG has discovered a new substance, which he terms Aldeide, its
composition being that of alcohol deprived of its water. It is obtained
by distilling alcohol or starch with anhydrous sulphuric acid. With
nitrate of silver a curious action takes place ; the metal is deposited
on the sides of the glass vessel in which the experiment is made, and
covers them with a coating of silver.

The same chemist has also discovered a new acid, agreeing in its
composition, with formic acid, with the addition of 2 atoms of water.
It is obtained by drying the formate of lead, and decomposing it by a
current of sulphuretted hydrogen.

It is a colourless liquid, congealing at 32^, and boiling at 212°. It
acts with prodigious energy on the animal textures, much more
powerfully than nitric acid. It destroys the skin like a hot iron ;
its smell is very strong when it contains an atom of water : it then
boils at 226°, and does not congeal at 32<^. — Journal de Chimie
Medic, i. 388, 2nd Ser.

IX. — On the Evaporation of Charae.

Those places in which Charae grow, are well known to fill the
surrounding air, in summer, with a very disagreeable odour. Pes-
sarini and Savi ascribe the cause to a volatile azotic principle, which
they term Puterin, They steeped a portion of these plants in water,
and allowed them to decay. A decomposition ensued, by which acetic
acid was formed, which dissolved the outer crust of carbonate of lime,

* Journal of the Bengal ^Society, March, 1B33, and Bibliotheque Universelle,
February, 1835.

156 Scientific Intelligence. , [Aug.

and disengaged carbonic acid, which remaining in the atmosphere,
formed a pellicle on the surface of the water. In the course of a
short time the smell became so strong that it affected with headache
persons subjected to its influence. The plants were gradually con-
verted into a black mass, consisting of threads and fine charcoal.
During the last putrefactive stage, the water was completely stinking,
blackish and slimy, and possessed on its surface a pellicle emitting a
very disagreeable smell.

Savi and Pessarini consider that the Puterin is one of the prin-
cipal causes of the Malaria in Italy, and that this matter, by its
deteriorating action in the heat of summer, deprives the plants of
their natural colour. When it is considered, however, that the charae,
in their living state, disengage chlorine, it is obvious that further
experiments are necessary, and that the explanation given is not satis-
factory, because the chlorine of growing plants would operate by
purifying the air deteriorated by the decaying ones. — Brandes'
Pkarm. Zeit. xi. 169, 183.

X. — Composition of Goat Fat.

The experiments of Chevreul, and others, led to the conclusion that
all vegetable and animal fixed oils were precisely similarly consti-
tuted. When they are treated, however, separately, with ether,
distinctions can readily be recognized. Thus, 1 part olive oil at 59^
dissolves in Ij times its weight of ether, while it requires 60 parts
of the same fluid to dissolve 1 part of mutton fat. Le Canu took
advantage of this fact, and shewed that animal oils contain a principle
hitherto undescribed : viz. Margarine. Dr. Joss of Vienna,* follow-
ing up the suggestion of Le Canu, has analyzed goat fat, and has found
it to consist of three principles, according to the following table : —
Elaine, soluble in cold alcohol of '815 . . . 5 42 (like olive oil)
Margarine, soluble in boiling, do. precipitating

on cooling 25*83 (yellowish)

Stearine, insoluble in boiling alcohol of '815 . 68*75 (white)

10000

XI. — Chemical Nature of the Secretions.

There are three principal membranes which furnish secretions in the
human body. These are, the skin, the mucous, and serous membranes.

1. The skin which covers the body externally, affords, by tran-
spiration, the sweat, which, in the healthy state, is acid. This acidity
is derived from the presence of acetic acid. Carbonic acid also is
transpired.

Dr. Donne has found, however, (Ann. de Ckim. Ivii. 398.) that
the sweat transpired between the toes, under the arm-pits, and around
the parts of generation, is alkaline. The skin of the dog and cat,
which do not perspire, is sensibly acid ; while, in the buck rabbit it
is alkaline, or neutral, and in the horse strongly alkaline. In these
animals there are analogous differences in the other secretions. For,

* Erdmann und Schweigger-Seidel's Journal fur praktische Chemie, iv. 369.

1835.] Scientific Intelligence. 157

the urine, which is acid in man, is acid in the dog and cat, but alka-
line in the horse and rabbit. The remarkable facts which Dr. Donne
has observed, and which deserves attention, is, that the sweat, during
disease in the human subject, becomes often neutral, and even com-
pletely alkaline. He has principally noticed this modification in
chronic diseases, and has obtained, in these cases, good results from
the employment of the vapour bath.

2. Mucous membranes. — Under this division may be included the
saliva, which in man, while healthy, is decidedly alkaline. This state
is generally ascribed to' the presence of lactates and muriate of soda ;
the saliva also when evaporated, and the residue crystallized, appears
to contain muriate of ammonia. It has been said that the saliva is
alkaline during mastication, and that it becomes neutral after eating.
Donne denies the accuracy of the latter statement, and affirms that
it always in the healthy state turns reddened turnsol paper to a blue
colour. In all those animals which Donne has examined, he has
found the saliva alkaline.

He has observed acid in a great number of cases of gastritis or
inflammation of the stomach, which has been verified by the applica-
tion of tests, and afterwards by inspection of the stomach after death.
He has seen several instances in which the saliva acquired its natural
or alkaline re-action by anti-phlogistic treatment, and has never
observed an acid re-action when the patient possessed a good appetite
and unimpared digestion.

The mucus of the oesophagus as far as the cardiac orifice of the
stomach appears to be neutral, at least during digestion. The mucous
membrane of the stomach, it has been concluded, from the researches
of Prout, Gmelin, and Tiedemann, secretes an acid fluid.

It is certain that if we examine the liquid contained in the stomach,
after all the contents of that viscus have been removed and its parietes
well washed we find it strongly acid. This has been explained by
Dr. Thomas Thomson, on the idea that common salt is decomposed
in the blood by the nerves of the stomach, and that the free acid thus
engendered is transmitted to the stomach. The whole""surface of the
stomach affords an acid re-action. At the beginning of the duode-
num, an alkaline re-action is evinced and appears through the whole
of this inferior portion of the digestive canal. This has been accounted
for^by supposing that the picromel acts as a base to the muriatic
acid and forms a salt. Donne, however, considers that the mucous
surfaces secrete an acid liquid. The liquid secreted by the pancreas
was found sometimes acid and sometimes alkaline by Tiedemann
and Gmelin. Yet by Leuret and Lassaigne, it was found to possess
all the characters of saliva.

The bile is alkaline. The mucous membrane of the urethra, pre-
puce and gland, afford an alkaline mucus. The nasal and bronchial
mucus present the same characters.

3. The serous membranes, as the peritoneum, the pleura, arach-
noid and synovial membranes, secrete an alkaline liquid, containing
muriate of soda, and corresponding with the serum of the blood.

This liquid in some cases becomes acid. The tears and the
humors of the eye are alkaline. From these facts it appears that
we may consider the human body as existing between two mem.

158 Scientific Intelligence. [Aug.

branes, the exterior one acid and the interior one alkaline. If we put
one of the poles of a galvanometer in contact with the mouth (the
negative pole) and the other with the skin, very decided currents
appear, and the needle deviates 15, 20, or 30 degrees.

Similar effects are produced between other organs in opposite
states with regard to chemical composition, but no currents were ob-
served between corresponding organs as between the kidnies, or be-
tween different portions of the intestines, or between the liver and
pancreas, &c.

Donne ascribes these phenomena to the chemical action which one
heterogeneous part exerts upon another. Matteucci denies that these
phenomena can be produced after death, and concludes, therefore,
that they are due to a vital and not to a chemical action, and draws
inferences which we have already noticed (Records, I. 102.)

Donne has repeated and varied his experiments, and affirms, that
after death the effects are the same as during life, that the head may
be cut off*, the spinal cord destroyed, and yet the currents may be
demonstrated, nay, even that if the stomach and liver be separated
from the body and taken in the hand, the needle will undergo a devia-
tion when the poles of the galvanometer are inserted in these organs.
The intensity of the action after death is diminished, it is true, but
this is sufficiently explained by the slowness with which the secreting
action of the organs goes on.

XII. — Esculic Acid.

When the Esculus hippocastanum or horse-chesnut is pulverized
and treated with alcohol, a yellow viscid matter is obtained by evapor-
ation. This substance resembles the saponine, which M. Bussy
extracted from the Saponaria. If this principle be treated with
acids at the temperature 212'^, a white matter is precipitated which
is esculic acid. Saponine, by the action of potash, is partly con-
verted into esculate of potash. Esculic acid is insoluble in water,
soluble in alcohol, and not in nitric acid, by which it is transformed
into a yellow rosin which dissolves in potash. Esculic acid consists
of carbon 58" 19, hydrogen 8-27, oxygen 34-54. The esculates of
potash, soda, and ammonia, are loo soluble in ammonia to crystallize.
Esculic acid was discovered by M. Freray. — Dumas Traite de
Chim. V. 296.

Xlll.— New Yellow Bye for Wool.^

Greooire Sella recommends the Rhus radicans as an excellent
dye. For eight parts of wool take of Rhus radicans, previously
boiled 8 parts, alum 1 part, cream of tartar ^ part, muriatic acid
solution (consisting of muriatic acid 4 parts, pure tin | or 1 part,)
1 part. Boil them for | of an hour ; a fine yellow colour is pro-
duced. If the dried plant is used, a pale yellow or hazel colour is
obtained. This colour resists soap and the sun as well as the other
yellow colours. It acquires greater stability if allowed to remain 12
hours in the vat.

• Bibliotheque Universelle, Feb. 8. 1835.

J

HORARY OBSERVATIONS OF THE BAROMETER, THERMOMf:TER, &e.

[Made at the Manse of the Parish of Abbey St. Bathan's, Berwickshire, Lat. 55o 52' N. Long. 2o 23 W. at

1 the height of about 450 feet above tlje sea, for the commencement of each hour per clock, beginning at 6

o'clock in the morning of Monday the 22d June, and ending at 6 o'clock in the evening of Tuesday the

23d, thus extending over 36 hours, according to the suggestion of Sir John Herschel.) By the Rev.

John Wallace.

10

11

12

54
55

561
57^
58^

58

57

54
56^

55^
56

55

53i
51

48f

46i

44

43^

42
41 i

41i

4U

41

4l2-

4U

47

481

49 i

51

51

53

1 50

47i

5H

4 51i

5 52

6 :)0«

49

27

13

i '11

28"895
28-881
28-867
28-837
28-816

28-802

28-800

28-791
28-791

28-799
28-778

28-786

28.806

28-823

28-838

28-859
28-878
28-882

28-891
28-905

28-925

28-925

28-92

28-923

28-926

28-932

28-935

28-941
28-940
28-934

28-931

28-939

28-937

28-939

28-942
28-948
28' 962

VV.S.W

W. S. W
W.

W.N.W

S. by W

w.s.w

Shifting.

w. s. w.

NWbyW

Remarks.

^ Strong wind, overcast, with tendency to rain ; an under stratum
^ of clouds in rapid motion.

Strong wind, occasional tendency to rain.
^ Under stratum of clouds nearly swept away, but the sky veiled
J with cirri and cirrostrati.

^ Light clouds driving before the wind under a bed of cirrostratus
^ which overspreads the sky ; occasional light showers.
J Nimbus along the western and northern horizon from S.W. to N.E,
5 sky still entirely veiled, light showers.

The s-dme nearly as at 11 A.M.

Tendency to clear ; large masses of cumuli in S.W. quarter ofhor.
i Cumuli abundant, chiefly in the horizon, and in rapid motion under
\ the upper stratum which veils the sky.

i Wind increasing, sky rapidly clearing, cumuli abundant, collected
5 in large masses on the western horizon.

"^Clearing ; a beautiful bed of cirri eastw^ard of the zenith, extending
\ from northward to southward, and farther eastward, in the same
3 direction, a bed of cirrostratus, a few floating masses of cumulus,
i Light cumuli floating over a blue sky, sun shining through a hazy
5 whiteness in the west, streaks of cirrostratus in the east.
) Cloudless, with the exception of the above mentioned thin hazy
\ whiteness in the west, and streaks of cirrostratus in the east.
} Cloudless, with the exception of cirrostratus in the east, which are
ji diminishing, and of a mass of black clouds above hor. in N W qr.
i Cloudless, with the exception of a mass of black hazy clouds seen
\ above the horizon in S.W. quarter, wind sinking.

Cloudles, with gentle breezes.

> Nearly cloudless, breeze gentle, faint streaks of aurora borealis rising-
\ from the horizon towards the zenith, a little e-dstward of north

A bed of cirrostratus northward of east, a little above the horizon,
the only exception to a clear sky ; calm,now and then sudden gusts»
iThe bed of cirrostratus noted -dbove disy)peared, another formed in
y N.E. quarter ; tendency to formation of cloud prevalent over the
J the sky ; calm, so that wind cannot be noted ; slight deposition.
\ Cirrostratus in N.E. qr. broken, gradually dissipating; hazy clouds-
\ forming round the hor.; hazy white clouds southd. of zenith ; calm.

Cirrostratus forming in western part of sky from N to S ; light wind.
} Calm and nearly cloudless, with a thin hazy whiteness chiefly dis-
\ cernable where the sun is situated.

i Gentle breeze, considerable masses of cumuli; the hazy whitenessp.
I accumul-dting in the eastern part of the heavens.

The cumuli much increased in magnitude ; breeze increasing.
^ Breeze decreasing ; a sudden shower ; cumuli moving in large mases ;.

> nimbi seen toward S.E. and N.E. Clear sky from windward to
J zenith, with cumuli floating over it ; hazy clouds in opposite qr.

Gentle breeze ; .skv clear overhead ; large masses of cumuli round
horizon to W. and S. E. and nimbus seen in the distance.
^During preceding hour wind became strong, and shortly sunk again

> into a gentle breeze ; nimbus seen in the western quarter : other-
j wise nearly the same as at 10 A.M.

^ Wind again brisk ; heavy masses of cloud in the horizon from S.W.
/ to S.E. passing here and there into nimbus. On the northern
I region of the heaven large masses of white cloud forming different
* stnita, and nearly at rest.
) Wind hushed ; a slight shower ; the sky nearly overspread with a

> cloud of the cumulostratus formation rising from a base in the
3 S.W. quarter; wind shifting southeastward.

"^The above mentioned cloud was speedily transformed into nimbns,
f when a heavy fall of rain, accompanied with hail, took place, but
? did not continue long ; calm ; sky partially clear ; nimbus still
3 prevailing in the N.W. quarter.

) During preceding hour another short but heavy fall of rain mixed
\ with hail; sky overspread with cirri and cirrostrati; cumuli below,

> Brisk wind ; sky overspread with cirri and cirrostrati ; large cumuli
\ floating below. [same as above described

Brisk wind ; skv gradujiUy clearing, but its general npitearance the

1

a

CO

C

• O

E^

03 ^

Q W

. ce
ai
>-»

<

o

CD

*E

CL,

C)

^

US

<

Cd

P5

Light wind, continued rain till 3 P.M. evening cloudy.

Calm, occasionally overcast, evening thick fog.

Morning fine, 11 A.M. overcast, with light showers, P.M. light rain, ev. fgy.

A.M. dense fog, P.M. cloudless but hazy, calm all day.

Calm, dense fog with little intermission.

Calm, A.M. tendency to fog, P.M. light haze, deposition in the evening.

Very calm, haze, occasionally cirrostratus in patches, deposition in evening.

A.M. calm, P.M. gentle breeze, cloudless all day, with light haze.

A.M calm and cloudless P.M. nearly cloudless with gentle wind, evg. calm.

A.M. calm and cloudless, P.M. brisk wind from S.E. heavy hazy cloudless.

Calm, cirri and hazy cumuli prevalent, P.M. thunder to the south, light rain,

Calm, with thick fog. [thick fog of the stratus formation.

Calm, morning hazy, haze partially dissipated during the day, evening cloudy

Brisk wind, occasionally cloudy, (cirri, cin-ocumuli and cumuli), ev. cloudless

Calm, A.M. cirri abundant P.M. overcast, evg. clear, 11 P.M. wind rising.

Brisk wind, for the most part overcast, evening cloudy.

Light wind, A.M. fog with light rain, P.M. cloudy.

Strong wind, cloudy or overcast, evening showery.

Gentle wind, A.M. cirri abundant, P.M. overcast and lowering, evg. cloudy.

Brisk wind, cumuli abundant on a clear sky, evening, clouds in heavy masses.

Rain until 7 A.M. strong wind, cloudy, and frequently overcast.

Strong wind, A.M. overcast and showery, P.M. clearing gradually, ev. calm.

Wincf alternately strong, brisk, and gentle, A.M. rain and hail, ev. calm, clear

Gentle wind, rain till 9 A.M. overcast and lowering, wind shifted to N. rain,

Strono- wind, A.M. rain, P.M. tendency to clear, with moderate wind, ev. clear

Gentle wind, cumuli floating over a clear sky, evening cloudy.

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RECORDS

OF

GENERAL SCIENCE

SEPTEMBER, 1835.

Article I.

On Racemic Acid. By Thomas Thomson, M.D., &;c., Regius

Professor of Chemistry in the University of Glasgow.

( Continued from p. 108. J

IV. RACEMATE OF SODA.

This salt may be formed precisely in the same way as the
racemate of potash. I obtained it in very small four-sided
prisms, apparently right-angled. Sometimes these prisms
terminated in two faces, applied to each other like the roof
of a house. Hence, I conceive that the base of the prism is
an oblique face. Very often the termination is a four-sided
pyramid. One of the edges of the prism is usually replaced
by a tangent plane. In general, this salt forms crusts com-
posed of an aggregation of minute and irregular crystals.

The taste is saline and bitter, but it approaches much
nearer to the taste of common salt than racemate of potash
does. Its specific gravity is 1-511. It is not sensibly soluble
in alcohol. 100 parts water, at the temperature of 63°,
dissolve 31-73 of this salt.

When heated, it does not melt as racemate of potash does,
but becomes brown, then swells up and burns with flame,
leaving carbonate of soda brown or gray, if kept long in
fusion.

105 grs. of crystals of racemic acid were exactly saturated
with carbonate of soda, and the solution being evaporated

VOL II. M

162 Dr. Thomas Thomson [Sept.

to dryness in a gentle heat, left 122 grs. of raceinate of
soda. Now, it has been shewn above, that 105 grs. of the
crystals contain 80*991 grs. of real racemic acid, which
require for saturation 39*268 grs. of soda, making together,
120*259 grs. Hence, the salt was composed of

Anhydrous racemate of soda . 120*259 or 12-25
Water 1*741 „ 0*177

0*177 rather exceeds the sixth part of an atom of water.
This small quantity m^st have been mechanically lodged in
the salt. Thus, it appears that racemate of soda is an anhy-
drous salt.

Tartrate of Soda.

This salt crystallizes in four-sided prisms, rather oblique,
and usually terminated by a bihedral summit. It is com-
monly obtained in long needles, consisting of four-sided
prisms, and having somewhat of a silky lustre. It is not
altered by being left exposed to the air.

The taste of this salt is saline, and it leaves in the mouth
an impression similar to that of glauber salt. Its sp. gr.
at 60° is 1*980. 100 parts of water at 61° dissolve 56*37 of
this salt. It is most sensibly soluble in alcohol.

When heated it fuses, but speedily loses its water and falls
to powder. It then becomes brown, and, at last, black ;
swells up and burns with flame, leaving carbonate of soda
in the state of a gray salt.

93*75 grs. of crystals of tartaric acid were saturated with
carbonate of soda, and evaporated to dryness in a gentle
heat. The silky crystals obtained weighed 151 grs. Now,
93*75 tartaric acid crystals contain 8*25 real acid, which
require 40 of soda to neutralize them. Hence, the salt was
formed of

Anhydrous salt .... 122*5 or 12*25
Water 28*5 „ 2*85

151*0
28*5 is very nearly 2J atoms of water. It is obvious, there-
fore, that tartrate of soda contains 2J atoms water.

The absence of water in the crystals of racemate of soda
constitutes a remarkable difference between it and tartrate
of soda. It is singular that it should be specifically lighter
than a salt which contains 2J atoms of water.

1835.] on Racemic Acid. 163

V. — RACEMATE OF BARYTE9.

This salt precipitates in the state of a white powder, when
chloride of barium and racemate of ammonia are mixed
together in atomic proportions, after having been separately
dissolved in water.

It is a tasteless salt, having a sp. gr. of 2-615. 100 parts
of water, at the temperature of 122°, dissolve 0*034 of this
salt. It is not sensibly soluble in alcohol.

When heated it does not melt, but becomes brown, and
burns like tinder, giving out a disagreeable fume, which
acts on the eyes, and smells exactly like lampic acid. A
white carbonate of barytes remains in a state of minute
division and very light.

To determine the composition of this salt it was dried in
the temperature of 100° till it ceased to lose weight; 20 grs.
were then kept for several hours in a temperature of 320°.
The loss of weight was 2*22 grs. When I raised the tem-
perature a few degrees higher, the salt began to lose its
white colour, when it was in contact with the glass. If we
admit that the salt, after being dried at 320°, still retained
0'03 grs. of water, its composition will be

1 atom racemic acid . . 8*25

1 atom barytes . . . . 9*50

2 atoms water .... 2*25

20-
Tartrate of Barytes.

This salt may be formed by a similar process as that which
answers for racemate of barytes. It is a white tasteless
powder, having a sp. gr. of 2*524. By an indirect experi-
ment I conclude that 100 parts of water at 63°, dissolve
0*133 parts of this salt.

When this salt is heated it exhibits the same phenomena
as the racemate, excepting that it burns with flame, and
that the carbonate of barytes remaining does not cohere,
but is in the state of powder, and much heavier than that
obtained from racemate of barytes.

When heated it loses no weight, unless the heat be sufii-
ciently high to act upon the acid. It is therefore, anhydrous,
and composed of 1 atom tartaric acid . 8*25

Irod^^) barytes ... 9*5

M 2 17*75

164 Dr. Thomas Thomson [Sept.

I stated in a former publication that bitartrate crystallizes
in right prisms with square bases. But I find, by a more
careful measurement, that the prisms are slightly obliq.ue,
and that the base also is slightly oblique.

VI. RACEMATE OF STRONTIAN.

This salt precipitates when solutions of chloride of
strontium and racemate of ammonia are mixed in atomic
proportions.

It is a white, soft, tasteless powder, having very much
the appearance of magnesia alba. Its sp. gr. is 1*409. At
the temperature of 135° 100 parts of water dissolve 0'104
parts of this salt.

When heated it gives oiF acetic acid, blackens, burns,
and leaves a white carbonate of strontian cohering together
in a friable mass .

20 grs. of racemate of strontian, previously dried in a
gentle heat, were exposed to the temperature of 330°, till
they ceased to lose weight. The loss was 4*5 grs. No
higher temperature could be applied without incipient
decomposition taking place. I conclude, from this experi-
ment, that the constituents of the salt are

1 atom racemic acid . 8*25
1 atom strontian . . 6*5
4 atoms water . . . 4*5

19-25

Tartrate of Strontian.

When dilute solutions of nitrate of strontian and tartrate
of potash are mixed together, no immediate precipitate
appears, but the liquid gradually deposits beautiful crystals
of tartrate of strontian. They are right oblique prisms.
Mon M' 113° 20', Pon M or M' 90°. They are transparent,
have a vitreous lustre, and resemble the finest specimens of
calcareous spar. When the saline solutions are concen-
trated the tartrate of strontian precipitates in powder.

This salt is tasteless. Its sp. gr. is 1*837. At the tem-
perature of 170° 100 water dissolve 0*67 of the salt. When
heated it gives out acetic acid, swells up like a cauliflower,
burns without flame, and, when acted on by the blowpipe,
leaves a very bulky friable carbonate of strontian. Its
constituents are

1835.] on Racemic Acid. 165

on Racemic Acid.

1 atom tartaric acid .
1 atom strontian . .
3 atoms water .

, 8-25

6-5
. 3-375

18-125
I heated 20 grs. of the salt (previously dried in a gentle
heat) in a temperature of 310°. The loss of weight was
1*87 grs. This scarcely amounts to 1^ atoms of water.
Hence, if the preceding analysis (made many years ago) be
correct, tartrate of strontian dried at 310° still retains the
half of its water. To determine the point I heated the
residual 18*13 grs. for two hours, in a temperature of 325°.
The portion in contact with the glass had become slightly
yellow, and the weight was reduced to 16*54. Thus, the
total loss was 3*46 grs. According to this result the consti-
tuents of the salt are. Anhydrous salt . 14*75

Water .... 3*085
This is rather less than 3 atoms of water, yet it confirms
the old analysis. Probably a little of the water had been
driven off when the salt was first dried.

VII. RACEMATE OF LIME.

We obtain this salt in powder when we mix together any
alkaline racemate, and any soluble salt of lime. I have
generally employed chloride of calcium and racemate of
ammonia, or of soda. It falls down in the state of a fine
powder, which may be washed, and dried on a filter.

The particles of this salt have the property of adhering
together somewhat like clay, and they stick to every thing
with which they come in contact while moist. This makes
it very difficult to wash it. The best way is to allow the
sediment of racemate of lime to subside in a tall, glass jar,
then to draw off the clear liquid and fill up the jar again
with distilled water. By repeating this process three or
four times, the salt will be washed. It may then be collected
and dried on the filter.

Racemate of lime is a white tasteless powder. Its sp. gr.
is 1*542. At the temperature of 58°, 100 parts of water
dissolve 0*029 of this salt. Boiling water takes up rather
more, but still, only a minute quantity. When heated to
450°, it becomes brownish yellow, shewing that a portion of
its acid has undergone decomposition. When the heat is

166 Dr. Thomas Thomson [Sept.

raised still higher the salt burns like tinder, becomes more
bulky, and assumes the appearance of a liquid boiling. At
last it burns with flame, and ultimately leaves a carbonate
of lime, slightly darkened by a mixture of charcoal.

To determine the water chemically combined with this
salt, it was dried at 140° till it ceased to lose weight. 20
grs. of this portion were heated to 450°, and kept in that
temperature till the colour began to become brown. The
weight was reduced to 13*47 grs. This residue was heated
in a crucible till it was converted into carbonate of lime.
This carbonate weighed 7*5 grs., equivalent to 4*2 grs. of
lime. Now, 4*2 grs. of lime require for saturation 9*9 of
racemic acid. Hence, the salt was composed of
Racemic acid . . . 9*9 or 8*25

Lime 4-2 „ 3-5

Water 5*9 „ 4*91

4*91 water is equivalent to 4^ atoms. I think it not unlikely
that the other frds of an atom were driven off by the first
heat of 140° ; and that racemate of lime dried in the open
air is a compound of

1 atom racemic acid . . . 8 '25

1 atom lime 3*5

5 atoms water 5*625

17*375
Had the temperature been raised to 150°, probably only
4 atoms of water would have remained.

Tartrate of Lime.

When this salt is obtained by double decomposition it
falls in the state of very minute crystals, which, instead of
cohering and forming hard lumps like the racemate of lime,
exist in the state of a loose powder, like sand. Hence, it
is easily washed, and dried on the filter.

It is a white, tasteless powder, having asp. gr. of 1*9009.
100 parts of water at 58° dissolve 0*013 of this salt, while
100 parts of boiling water dissolve 0* 17 of it. When heated
nearly to redness, it burns like tinder, and leaves carbonate
of lime.

Its composition seems exactly the same as that of race-
mate of lime. 20 grs. of it, previously dried in the same
temperature as the racemate had been, were exposed for an
hour to the heat of 310°. The loss of weight was 4*94 grs.

1835.] en Racemic Acid, 167

The heat being raised to 326°, and continued for three hours
longer, the weight of the salt was reduced to 13*85 grs., but
the salt was discoloured. This residue being burned, left
7*5 grs. of carbonate of lime, equivalent to 4*2 grs. of lime.
This being precisely the same result as with racemate of
lime, it is clear that the composition of both must be the
same.

VIII. — RACEMATE OF MAGNESIA.

Racemic acid does not occasion a precipitate when dropt
into a solution of sulphate of magnesia ; neither is any pre-
cipitate produced by racemate of soda. But if we mix solu-
tions of racemate of soda and sulphate of magnesia in the
atomic proportions, evaporate the liquid to dryness, and
then digest the dry residue in water, a white residue re-
mains, which IS racemate of magnesia.

It is tasteless, has a sp. gr. of 1*980, and at the tempera-
ture of 64°, 100 parts of water dissolve 0*35 parts of it.

Magnesia alba dissolves easily in an excess of racemic
acid in water, when the action is assisted by heat. When
this solution is concentrated, racemate of magnesia is depo-
sited in crystalline crusts. It is difficult to free these crusts
from all excess of acid. After repeated washings they still
reddened litmus paper. But the addition of a very minute
quantity of ammonia rendered them alkaline. It is clear,
from this, that the salt was a simple racemate, with a very
slight excess of acid.

10 grs. of the racemate, formed by double decomposition,
when heated to redness, burned like tinder, and left 1*95 grs.
of magnesia. The salt being neutral, must have been com-
posed of Magnesia . . 1950 or 2*5

Racemic acid 6*435 ,, 8*25
Water . . . 1*615 „ 2*07

10*000
The water is rather less than 2 atoms, probably because
the salt had been dried by artificial heat.

The sp. gr. of the racemate obtained by dissolving mag-
nesia alba in racemic acid, was only 1*32. It was a com-
pound of 1 atom racemic acid . 8*25
1 atom magnesia . . 2*5
^ 4i atoms water . . . 5* 0025

15-7525

168 Dr. Thomas Thomson [Sept.

The water actually obtained was 5* 17. This great excess of
water in the crystallized salt explains why its specific gravity
is so much less than that of the precipitated salt.

Tartrate of Magnesia.

This salt is easily obtained, by mixing solutions of tartrate
of soda and acetate of magnesia in atomic proportions. The
tartrate of magnesia precipitates.

It is a snow-white powder, consisting of very minute
crystals. When moistened and dried slowly it is apt to
concrete into lumps. It is tasteless, yet a 'slight impres-
sion of bitterness is perceptible when the salt is kept for
some time in the mouth. Its sp. gr. is 1*960. 100 parts
of boiling water dissolve 0*6 of it; and its solubility is not
much inferior in cold water.

The constituents of this salt, according to an old analysis
of mine, are as follows :

1 atom tartaric acid . . 8*25

1 atom magnesia . . . 2*5

2 atoms water .... 2*25

13-
Thus, in its constitution, it bears a striking resemblance to
racemate of magnesia.

The bitartrate of magnesia has an acid taste, and crystal-
lizes in needles. It contains only 1 atom of water.

I have been induced to give a description of the eight
preceding racemates, and the corresponding tartrates, to
enable the chemical reader to compare them with each
other. But it would draw out this paper to too great a
length were I to continue this comparison farther.

IX. RACEMATE OF ALUMINA.

To obtain this salt, 105 grs. of crystals of racemic acid
were dissolved in water, and the liquid was digested for
three weeks, in a flask, with 21*25 grs. of alumina, previ-
ously ignited. Not a particle of the alumina was dissolved,
but it was gradually converted into a bulky white powder,
a portion of which adhered obstinately to the glass.

It was a snow-white, tasteless powder, insoluble in water.
When heated it decrepitates, and then becomes black, in
consequence of the destruction of the racemic acid.

1836.] on Racemic Acid. 169

10 grs. of this salt, after exposure for some hours to a
heat of 340°, lost 1.66 grs. The residue, which was still
white, being ignited in a platinum crucible, became black.
Being drenched in nitric acid, and again ignited, there
remained 2*30 grs. of pure white alumina. If we suppose
the heat of 340° sufficient to drive off all the water, it is
obvious that the salt was composed of

Racemic acid . 6*04 or 8*25
Alumina . . . 2-30 „ 3-141
Water. . . . 1-66 „ 2*26
2*26 is almost exactly 2 atoms of water; and 3' 141 is very
nearly If atoms alumina. I have some doubts whether the
f ths of an atom of alumina was really united with the acid ;
for, when the salt was ignited it was converted into a black
mass, through which white dots were scattered. I think it
not improbable, that these white dots were portions of alu-
mina, which had not been united to the acid. If this sup-
position be well founded the constituents of the salt will be
1 atom racemic acid . . 8*25

1 atom alumina . . . 2*25

2 atoms water .... 2*25

12-75
Tartaric acid acts in a very different manner on alumina
than racemic acid does. It dissolves hydrated alumina with
facility, and, on evaporation, it forms a viscid transparent
matter, like gum-arabic. It has an acid and sweetish taste,
and is probably a bi-tartrate. When washed with water a
white matter remains, brittle, and easily reduced to powder.
It is tasteless and neutral, and is composed of

1 atom tartaric acid . . 8*25
1 atom alumina . . . 2*25
1 atom water .... 1*125

11-625

X. RACEMATE OF IRON.

Racemic acid dissolves iron by the assistance of heat,
with the evolution of hydrogen gas, and soft white needles
of racemate of iron are deposited. The easiest method of
obtaining this salt is to dissolve 173*75 grs. of crystallized
sulphate of iron in 4 cubic inches of boiling water ; to put
the solution into a phial, which it almost fills. 122J grs. of

170 Dr, Thomas Thomson [Sept.

racemate of soda, in powder, are introduced at the same
time, and then the phial must be well corked and agitated.
As the racemate of soda dissolves, the liquid becomes white
and opaque, and a soft white matter is gradually deposited,
which is racemate of iron. It may be collected on a filter,
and washed two or three times with cold water. But, as it
is not quite insoluble, we must not persist too long, other-
wise we would lose the whole salt. While drying, it assumes
a yellowish or buff colour, probably in consequence of ab-
sorbing a little oxygen.

Racemate of iron obtained by this process is a soft powder
which adheres to every thing it touches. Its taste is sweetish
and astringent, like the other salts of protoxide of iron.
At 58° 100 parts of water dissolve 0-38 of this salt. The
solution has rather a deep yellow colour, and an inky taste.
100 parts of water, almost boiling hot, dissolve only 0*4 of
this salt, or very little more than water at 58° does.

When the aqueous solution is evaporated to dryness, the
racemate is obtained in the state of a semi-transparent dark-
green crust, seemingly crystalline, though no distinct shape
could be made out.

When the salt is raised to the temperature of 400° it takes
fire and burns like tinder, and the spontaneous combustion
continues though the vessel be removed from the sand-bath.
After the combustion is at an end, nothing remains but per-
oxide of iron.

To determine the composition of this salt, 20 grs. of it,
previously dried in a gentle heat, were left for 24 hours in
the vacuum of an air pump, over sulphuric acid. The
weight was reduced to 12*95 grs. Being now heated to
400° it underwent spontaneous combustion, and left 4*7 grs.
of peroxide of iron, equivalent to 4*23 grs. of protoxide.
Now, 4*23 grs. of protoxide require for saturation 7*74 grs.
of racemic acid. Hence, the constituents of the salt are
Racemic acid . . . 7*74 or 8*25
Protoxide of iron . 4*23 ,, 4*5

Water 0-98 „ 1-042

This is very nearly 1 atom racemic acid . . 8*25
1 atom protoxide of iron . 4*5
1 atom water .... M25

13-875

1835.] on Racemic Acid, 171

Peroxide of iron combines with racemic acid, and forms
a red coloured salt, having a harsh and astringent taste,
which I did not particularly examine.

XI. — RACEMATE OF MANGANESE.

This salt may be obtained by digesting a solution of race-
mic acid over carbchiate of manganese. The carbonate
gradually assumes the form of a flesh-red powder. After
being dried in the open air it was placed for 48 hours in
the vacuum of an air pump, over sulphuric acid. 200 grs.
thus treated lost only 0*9 grs.

The salt thus dried, when put into the mouth, is, at first,
tasteless, but, at last, it gives a slight impression of sweet-
ness. Its sp. gr. is 1*960. 100 water at 55° dissolve 0*048,
and at 212° 0*14 of this salt.

20 grs. of this salt, by exposure for two hours to a heat
of 270°, were reduced to 18*06 grs. In another experiment
20 grs. heated to 330° were reduced to 17 grs.

20 grs., by ignition, were reduced to 6*38 grs. of red
oxide, equivalent to 5*94 grs. of protoxide. In another
experiment, 20 grs. left Q'Q grs. of red oxide, equivalent to
6*06 grs. of protoxide. The mean of the two gives 6 grs.
of protoxide from 20 grs. of the salt. The constituents,
therefore, must be

Racemic acid . . . . 1 1 or 8*25 = 1 atom
Protoxide of manganese . 6 ,, 4*5 = 1 atom
Water 3 „ 2*25 = 2 atoms

20
Thus, the constitution is the same as that of tartrate of
manganese. But it is less soluble in water.

When solutions of chloride of manganese and racemate
of soda, in the atomic proportions, are mixed together,
racemate of manganese precipitates in beautiful crystalline
crusts, having a fine, flesh-red colour, but the shape of the
crystals could not be recognized.

XII. RACEMATE OF NICKEL.

When solutions of sulphate of nickel and racemate of
soda, in atomic proportions, are mixed together, a fine
light-green powder gradually precipitates, which is race-
mate of nickel.

172 P. C. OH the Colours that enter into the [Sept.

It is tasteless, yet leaves a disagreeable impression in the
mouth. Its specific gravity is 1-76176. 100 parts of water
at 57°, dissolve 0*056 of the salt. The solution is colourless
and tasteless. 100 parts of boiling water dissolve 1*724
parts of it. The solution has a fine green colour, and when
cooled slowly, deposits the salt in small crystals, which,
under the microscope, seem to be flat rectangular prisms,
with rectangular bases.

When this salt is heated, it gradually blackens, then
burns with a strong flame, and the greatest part of the
nickel is volatilized ; for, 20 grs. of the salt, treated in
this way, left only 1^ gr. of peroxide of nickel.

To form an estimate of the quantity of combined vrater

which it contained, 20 grs. of it were left for 24 hours in

the vacuum of an air pump, over sulphuric acid. The

weight was reduced to 16*62 grs. This residue being heated

for two hours on the sand-bath, in a temperature of 284°,

was reduced in weight to 14*25 grs. Now, if this residue

was anhydrous, it must have contained 4*845 oxide of nickel,

and 9*405 racemic acid. This would make the constituents

Racemic acid . . 9*405 or 8*25

Oxide of nickel . . 4*845 „ 4*25

Water 2*370 „ 2*08

16*620
If we admit that the salt dried at 284° still retained a very
little water, the combined water will amount to two atoms.
This, doubtless, represents the true constitution of the salt.
Carbonate of nickel may be dissolved in an excess of
racemic acid, by the assistance of heat. On cooling, a
bluish green powder falls, inferior in beauty, to the race-
mate, by double decomposition ; but, its constitution is the
same. (To he continued.)

Article II.

On the Number and Character of the Colours that enter into

the Composition of White Light. By P.O.

( Continued from p. 119.J

It was my intention, when I concluded the last paper on
this subject, to proceed to some experiments of a different
character ; but the highly interesting papers on Accidental

1835.] Composition of White Light. 173

Colours, by C. Tomlinson, Esq., published in your two last
numbers, which have introduced new methods of obtaining
these colours, have very naturally recalled my attention
to this part of the subject; and, as Mr. Tomlinson considers
the results of his experiments to be opposed to the existing
theory, (20.) which it was partly the object of my last paper
to support, my observations on them may be given, without
any impropriety, as a continuation of these papers ; more
particularly, as they will be found to be connected with
their principal object.

If we look at the reflection of objects from the first sur-
face of coloured glasses, we find they preserve their proper
colours, very little modified by the colour of the glass. This
is what might be expected ; for, as the light reflected by the
first surface does not enter into the glass, it is not probable
that it will be changed by it; the modification, when any is
observed, it may be concluded, arises from a mixture of the
light reflected by the second surface ; the images formed by
the two reflections, under ordinary circumstances, being
very little separated, are usually seen blended together.

In Mr. Tomlinson's first experiments, the circumstances
are highly favourable, both to the formation and to the
separation of the two images ; for the mercury, under the
coloured medium, must insure a total reflection from the
second surface ; and the depth of the medium, by consi-
derably extending the inclined path of the incident light
before it reaches the second surface, must separate the two
reflections.

The latter object is not so completely attained by the
method proposed in the second paper, in which a mirror
and coloured glasses are substituted for the previous arrange-
ment; because, in order to obtain a sufficient reflection
from the second surface, the coloured glass must be thin,
and the separation of the images is wholly dependent on
the distance between the first surface, and the surface which
forms the second reflection.

In repeating Mr. Tomlinson's experiments, which I have
done, perhaps not so completely, by putting pieces of coloured
glass upon a common looking glass ; I have, in some degree,
obviated this objection, by keeping the coloured glass at
some distance from the surface of the mirror ; this produces

174 P. C. on the Colours that enter into the [Sept.

a sufficient separation of the two reflections, but it is open
to the objection, that the reflection from the second surface
of the coloured glass, is mixed with the reflection from the
first surface : in practice, however, I have never discovered
any inconvenience from the superposition of the two reflec-
tions; the accidental colour being, as far as I can judge,
precisely the same as that obtained by placing the coloured
glass close to the mirror. This, though at first view it
appears to be attended with some difficulty, is perfectly
consistent with the principles we have advanced ; the eye,
under the influence of a stronger impression of the same
kind, is insensible to the smaller quantity of coloured light
within the shadow.'^

I have since improved upon this method, by placing the
coloured glass upon a mirror, inclined towards the window,
as in the last experiment, and by then raising the edge of
the glass nearest the window, until the two images oiF the
finger, placed so as to form a shadow, are sufficiently sepa-
rated : the object being to reflect the light from the mirror
through that part of the coloured glass from which the
direct light is excluded, is thus readily accomplished.

• The complementary colours sometimes exhibited by shadows, in coloured
rooms, may be explained upon the same principle.

The room in which I am sitting is painted a reddish drab ; and there being two
windows in it, at some distance from each other, objects placed to intercept the
light, form two shadows upon the opposite wall ; both these shadows are, of course,
enlightened by one window only, and I have frequently been struck with the blue
or rather, violet appearance of shadows, thus partially illuminated, when my mind
has been occupied with subjects of a different character. The eye, in this case,
impressed with the light of both windows, reflected from the coloured walls, is
not only insensible to the feeble excess of colour within the shadow, but, also, to
the light of the same kind, which enters into tlie composition of the white light
that accompanies it. I have generally observed that, to a certain extent, the less
the shadow is enlightened, the more distinctly it appears of the complementary
colour of the room.

To satisfy myself of the correctness of this explanation, I received the shadow
of an object partly upon a sheet of white paper, and partly upon the wall against
which the paper was placed ; upon examining the divided shadow I could discover
no difference in the accidental colour produced under these different circumstances,
except, perhaps, a little more distinctness of colour in that part of the shadow
which fell on the white paper. When the accidental colour is not seen upon first
viewing the shadow, it may generally be discovered by looking at the enlightened
wall and the shadow, in succession.

Probably the vivid appearance of accidental colours, when the eyes are closed
after being impressed, may be attributed to the same cause : viz. the insensibility
of the eyes to colours so suddenly and greatly reduced in intensity.

1835.] Compositionof White Light. 175

It will be seen, upon an inspection of the two images,
that the accidental image is formed by light reflected from
the first surface of the coloured glass, without any admix-
ture of coloured light from the mirror ; this part of the
mirror being invariably occupied with the shadow of the
finger ; the accidental image, therefore, always corresponds
with the shadow of the intercepting object, which, by suf-
fering it to overlap the coloured glass, will be seen conti-
nued upon the mirror in corresponding lines. The coloured
image, on the contrary, is regulated by the position of the
coloured glass, and is evidently formed by the coloured light
reflected by the mirror through that part of the glass, from
the first surface, of which there is no reflection, the direct
light being intercepted by the finger. The accidental
image, then, is formed by the light reflected from the first
surface only ; the coloured image is formed by light trans-
mitted twice through the coloured glass, without any mix-
ture of the light reflected by the first surface ; and the
remainder of the glass derives its colour from a mixture of
both. Hence it is, that the coloured image is much more
brilliant than the general surface, the latter being dieted
with the white light reflected by the first surface. The
coloured image is beautifully transparent, while the other
parts of the surface exhibit a slight degree of opacity, or,
what may be termed, a glassy appearance, arising from the
first reflection, which is the more conspicuous from its being
formed, whatever may be the colour of the reflectors of
white light.

The two images being thus accounted for, we have now
to explain how the one becomes the accidental colour of the
other.

We are not to suppose, because the light reflected by the
first surface is white, that the image formed by it must be
a white, corresponding with the surrounding atmosphere ;
the quantity of light thus reflected is so small, that it ought
to be invisible to an eye impressed with this light ; and
this, in fact, is the case ; the image being frequently seen,
when the eye has been previously occupied with strong
white light, nearly, or quite black ; ''^ as the eye gradually

* Mr. Delaval observed that all coloured liquids appeared black by reflected
light, when there was no reflection from the second surface.

176 P. C. on the Colours that enter into the [Sept.

recovers its power to perceive weaker light, the black image
becomes lighter, and at length assumes a gray appearance,
such as might be expected from a small quantity of white
light reflected from a black ground. The change from
black to gray corresponds in its circumstances with the
gradual appearance of objects in a dark room, after the eyes
have been exposed to strong light.

But, unless the eye be steadily directed to the object,
the image, instead of becoming gray, assumes the appear-
ance of the accidental colour, of the colour by which it is
surrounded. If we look steadily at the image, so as to
preserve the gray appearance of it, the accidental colour
will in a short time be seen upon its margin, from the
involuntary motion of the eyes, precisely as it is observed in
looking at a white object upon a coloured ground ; and, the
slightest motion of the eyes, which, with the exception of
the accidental image, are wholly impressed with the colour
of the ground, extends it until the colour becomes uniform,
which, indeed, it is not easy, for any length of time, to
prevent.

If we look from one image to the other, which we naturally
do when we make the experiment without any particular
caution, the accidental colour is much finer than when the
eye is impressed with the coloured ground only ; the coloured
image being much more vivid than the ground upon which
it is seen.

In order to satisfy myself of the correctness of this ex-
planation, I made such an arrangement that the whole of
the coloured glass, with the exception of the two images of
my finger, which formed the shadow, was covered ; so that,
upon looking at the two images in succession, the accidental
image fell upon a part of the eye which was impressed with
the coloured image, and upon a part of it not thus impressed,
alternately ; in the former case, it assumed the accidental
colour, and in the latter, the gray appearance I have before
described : the result of the experiment was very decided,
as, by a slow motion of the eye, both colours were seen at
the same time. The alternations ought not to be too rapid.

When the coloured glass is tilted considerably, a breadth
of white light is reflected by the mirror to the under side of
the coloured glass, which meets the eye after one transmis-

1835.] Composition of White Light. 177

sion, and which is, consequently, of a lighter colour : the
experiments hefore described, being repeated in this light,
produced the same results.

When the experiment was made with orange-yellow glass,
the accidental colour was violet ; with green glass, the acci-
dental colour was crimson ; and with crimson glass, green :
thus confirming, as far as I have proceeded, by a new and
unexpected method, the results of my former experiments.

The principle upon which this explanation has been
attempted is applicable to a variety of other subjects.

The effect of contrast in heightening colours is well
known ; but, I believe, not satisfactorily accounted for ; at
any rate, the combinations which produce the best effect
are not reduced to any fixed rules ; and as the subject is of
great importance to the artist, and to others who have any
thing to do with the arrangement of colours, I may be
excused, perhaps, if I lengthen this communication, by
shewing in what manner the principle upon which acci-
dental colours are formed is applicable to it.

Objects, though they appear of a particular colour, gene-
rally reflect light of the three primitive colours ; and the
light thus reflected, forms white light until either one or
two of the colours are exhausted ; leaving the colour, or
colours, in excess, diluted with the white light thus formed,
to exhibit the proper colour of the body from which it is
reflected.

If, then, we look, at a coloured body, when the eye has
been previously prepared by looking at its complementary
colour, we not only see the colour which distinguishes it,
with full effect, but we also see the white light which
accompanies it, converted to the same colour ; thus, adding
to the quantity of the coloured light in excess, and, at the
same time, increasing its intensity, by removing the effect
of the white light, by which, when the eye is not rendered
insensible to the complementary colour of the object, the
primary colour is diluted.

On the contrary, if we prepare the eye by looking at the
same colour, instead of the complementary colour, or at
any compound colour of which it forms a part, the colour of
the body is lessened in intensity ; in some cases, so much so
as to be wholly lost, and even converted to its complemen-

VOL. II. N

178 P. C. on the Colours that enter into the [Sept.

tary colour. When, for instance, we look for some time at
the lackered knob of a lock, upon a door, originally white,
but rendered yellow by the usual effect of time, the white
appears to recover its former purity ; and when the eye
directed to it has been too much impressed to stop at this
point, it is converted to violet, its complementary colour ;
or, if we look for a short time at crimson and red, alter-
nately, the former approaches to violet, and the latter
appears of a dull brick colour.

It may be supposed that when two colours are brought
near to each other, as in a picture, for instance, the eye
does not rest long enough upon one of these colours to pro-
duce any effect with regard to the other; or, that the
colours occupy different parts of the eye, and, therefore, do
not interfere with each other ; but the facts are otherwise ;
if the eye rests upon a colour for a few seconds only, or
when the transition from one colour to the other is so rapid
as only to give time to observe the different colours, as
exemplified in the two coloured shadows we have been
treating of, it produces a very decided effect ; and it will be
found that however near the colours are to each other,
there is a slight motion of the eye, when the attention is
turned from one to the other, which brings them in succes-
sion to the same part of it.

These observations are verified by several of the preceding
t experiments ; and by many others which I have not con-
sidered it necessary to insert. It appears, from them, that
to exalt a colour it might be placed near its complementary
colour ; and that to depress it, the eye must be prepared by
the same colour, or a compound colour in which it takes a
part. Nature has given us many examples ; her finest
productions are frequently heightened by contrast ; even
the bloom of the rose derives additional beauty from the
green leaves which surround it.

The phenomena of accidental colours are highly interesting
and instructive ; the colours are produced with a facility
which those who are not familiar with the subject are not
prepared to expect ; and there is no appearance connected
with them, that I am acquainted with, which does not admit
of an easy and simple explanation upon the received theory.
We cannot, however, attribute the appearance of accidental

1835.] Composition of White Light . 179^

colours to insensibility of tRe eye arising from fatigue or
exhaustion ; because the preparation for this formation
commences instantaneously, and two colours, complemen-
tary to each other, as we have seen in a former experiment,
may be both exalted by the most rapid transition.

I have before noticed that the motion of the eye-lids
preserves the power of the eyes to distinguish colours.
From some observations I have since made, I am disposed
to attribute this to the influence of the accidental colours
of the objects in view; formed in the eyes when they are
closed, though, from the rapidity of the motion, they are
not visible. In making some experiments with the green
centre of a hearth-rug, in order to determine the shortest
time in which its accidental colour might be seen, I found
that a beautiful crimson, approaching to scarlet, was pro-
duced, by looking at the rug only time enough to form a
distinct perception of its colour, which occupied less than
a second ; and that if the eyes were closed a little more
deliberately than when it is done by the usual involuntary
motion, the accidental colour was seen, before the eyes were
quite closed. Upon repeatedly opening and closing the
eyes, so as just to give time to form a distinct perception of
the primary and accidental colours in succession, I observed
that the colour of the rug, so far from being lessened in
intensity, was rendered more vivid than when the eyes
were first directed to it.

The accidental colour in this experiment, is not correctly
complementary, in consequence of the more ready admis-
sion of the red than the violet light, through the eye-lids ;
after the accidental image has been some time formed, it
approaches nearer to its proper colour. P. C.

To the Editor of the Records of General Science,
Weston Super Mare, July 16, 1835.

Note hy the Editor. — It is an interesting circumstance, that
while so many of our pages have been devoted to inquiries
into the nature of light and its modifications, the same sub-
ject should be taken up by a foreign contemporary. M.
Plateau, in a very excellent paper published in the Annales
de Chimie et de Physique, Iviii. 337, proposes a theory for
the explanation of accidental colours, after disscugsing at

n2

180 On the Colours that enter into the [Sept

considerable length, those which have been previously pro-
posed. The latter amount to eight.

1. The earliest theory was that of Jurin, detailed in his
Essai sur la Vision JDistincte et Indistincte, inserted in Smith's
Optical Treatise. He considers the phenomena of accidental
colours to depend on this principle : that when we have
been for some time affected with a sensation, immediately
on our ceasing to be affected with it, a contrary one is pro-
duced, sometimes by the act of cessation, and at other times
by causes which on another occasion would scarce produce
the same sensation in any degree ; or, at least, not in the same
intensity. Thus, after looking at a brilliant object, if we fix
the eye upon a wall, an image of the object will be observed,
but it will be the reverse of brilliant. Analogous cases
occur with regard to the other senses. After great and
tedious pain, a pleasurable sensation follows. The intensity
of a cold bath is succeeded by great heat. When we pro-
ceed from a strong light into a dark chamber, we seem to
be enveloped in obscurity, but after remaining for some time
the room appears to be deprived of its darkness.

2. Scherffer published a theory in 1761, [Dissertation sur
les Couleurs Accidentales^ Journal de Physique de Rozier,
xxvi. 1785.) which is of the following import: If a sense
receives a double impression, one of which is strong and
lively, and the other weak, we are not sensible of the latter.
This ought to happen principally when they are of the same
species, or when a strong action of an object upon some
sense is followed by another of the same nature, but much
milder, and less powerful in degree. Thus, if, after looking
attentively at a green object, we direct the eyes upon a
white ground, the eye being fatigued by long attention to
the green colour, and being then suddenly cast upon the
white surface, is not in a condition readily to receive a
weaker impression of green rays. Now, all the modifica-
tions of light are reflected by the white surface, but the
green is less in quantity, compared with what reached the
eye from the green ground. If, then, we fix the eye upon
white paper, those parts of it which had previously re-
ceived a stronger impression of green light than the others,
cannot now appreciate all the effect of this light.

This theory, slightly modified by others who have adopted

1835.] Composition of White Light. 181

it, ascribes the cause of accidental colours to the diminution
in the sensibility of the retina, in consequence of its being
fatigued by a prolonged impression from a particular set of
rays, without the qualification that the second impression
should be more feeble than the first.

3. Another theory proposed by Scherfi(er, considers the
accidental image as the consequence of the prolongation of
the feebler impression, produced by rays different from the
predominant colour of the object.

4. De Godart advanced two theories in 1776, {Journal de
Physique, viii. i.) He endeavours to prove by experiment
that the scale of tones of vision is as follows, beginning with
the highest : Black, blue, green, red, yellow, white. He
supposes that, after looking at a coloured object, if w^e cast
the eye upon a white ground, the continued direct impres-
sion produced by the object, acts upon the sensation from
the white, so as to lower the tone, and, this diminution is in
proportion to the elevation of the original impression. For
example, if we look at a red object, as the red impression
which remains on the eye is raised, according to the scale,
three tones above the black, it will lower the white the
same number of tones, which will reduce it to green, the
accidental colour of red.

5. The second theory of De Godart appears to be a modi-
fication of that of insensibility. It supposes that a fibre,
acted upon by one object, remains incapable of communi-
cating the sensation of another, as long as it preserves the
impression of the first ; and that the different colours being
expressed by portions of the same fibre, which are propor-
tionally short according to the vividness of the tone ; that
part which has not acted, being excited by the white, pro-
duces the accidental colour. That is, if we look at a red
object, and cast the eyes upon a white ground ; then,
according to De Godart, the only portion of the fibre which
has not been acted on, will be excited to vibrate by the
white, and will produce the sensation of green. If the red
impression affects the eye, red and green, that is, white
will be perceived ; or, in other words, no accidental colour
will be seen.

6. Darwin adopted the principle that the retina becomes
insensible, in consequence of fatigue from the action of the

^^ On the Colours that enter into the [Sept.

same set of rays combined the idea of contrary sensations,
advanced by Jurin. Thus, the green image seen when the
eyes are cast upon a white ground, after having been fixed
upon a red object, proceeds from two causes :

1. The retina, fatigued by the red, has become insensible
to the rays' of this colour, and is now only affected by the
complementary green.

2. This part of the retina takes on, spontaneously, an
opposite mode of action, which produces the sensation of
the complementary green colour.

Hence, we see that if the accidental image, (or inverse
spectrum, as Darwin calls it, in opposition to direct spectra,
that is, to the images which preserve the colour of objects),
is observed in a dark place, or on a coloured surface, its
production may be explained by attributing it to the second
cause alone ; for, from the nature of this cause, the acci-
dental colours may be produced without the participation
iof external light.

7. The theory of contrast was developed in the year 13,
by Prieur of Cote d'Or, in a memoir read to the Institute.
(See an analysis of it in Annates de Chimie, vol. liv.) He
employs the word contrast to characterize the effect of the
simultaneous prospect of two differently coloured objects.
In other words, it is a comparison from which results the
perception of some difference, either great or small ; and
further, the new colours developed by contrast, are always
conformable to the shade from which they were obtained,
by extracting from the peculiar colour of the one body, the
rays analogous to the colour of the other body. Thus, in
certain circumstances, a small stripe of orange paper, placed
upon a leaf of red paper, appears yellow, that is, a colour
which may be considered as orange deprived of its red.
Upon yellow paper it appears red.

8. Sir David Brewster (Edinh. JSncyclop.i., Philosophic.
Mag. iv. 354., Letters on Natural Magic, p. 22.) compares
the state of the eye during the contemplation of a coloured
object, to that of the ear during the perception of a sound ;
and admits that the vision of the primary and accidental
colours are simultaneous, in the same manner that the
fundamental and harmonic sounds are perceived by the ear
at the same time. Thus, the green accidental colour which

1835.] Composition of White Light. 188

is produced by the red, exists on the retina while we look
at the red object, and when we cast our eyes upon a white
ground, the green impression, which is then isolated from
its combination with the primary impression, is added to
the white impression. The following are illustrations of
this theory :

1. " The effect of this vision of green is to cause the red
to appear paler, by mixing with it. The red and the green
tend to produce white. But, as the direct red predominates
greatly over the accidental green, the result is always a pale
red."

2. If, after looking at a stick of red wax, long enough to
occasion an intense accidental colour, (still looking at the
wax), we approximate the eye to the flame of a candle,
which is placed in such a manner that the rays proceeding
from the object to the eye pass close to the flame; then
the colour of the wax ceases to act upon the retina, and
appears black ; the stick, at the same time, ajipears covered
with a feeble greenish phosphorescent light. In this in-
stance the accidental image appears to exhibit itself during
the contemplation of the coloured object.

3. In an apartment painted with a bright colour, and
upon which the sun shines, the parts of the furniture upon
which the light does not fall directly, appear tinted with
the complementary colour. Again, when the light of the
sun penetrates through a small aperture, in a coloured
stuff curtain, if the light is received on white paper, its
colour is complementary to that of the curtain.

Plateau objects to the first experiment, because he sup-
poses that Sir David Brewster probably placed the coloured
object upon a white ground, as when we wish to observe
tlie accidental colours. In this case, after looking long at
the object, its colour would be diluted by the white. The
object ought to be insulated and placed on a black surface.
Then the colour, instead of becoming paler, would be darker.
This may be illustrated by placing a piece of red paper on a
black ground. Look at the paper steadily, keeping the eye
upon the same point ; then, without changing the position of
the eye, place by the side of this paper a second piece of the
same coloured paper. It is obvious that the image of the latter
falling upon a different part of the retina, . will serve as a

"Idl On the Colours that enter into the [Sept.

means of comparison, and will enable us to appreciate the
apparent alteration experienced by the colour of the first.
Now, this change is rendered very sensible ; the paper
which has produced a prolonged impression appears darker
than the other. We are also certain, by this means, that
the alteration in the colour of the object is progressive :
that is to say, at first feeble, and, increasing with the length
of time that it is contemplated. In the second experiment.
Plateau conceives that the conclusion drawn is not at all
evident : viz. that the two colours exist at the same time,
since it is obvious, from the wax appearing black, that the
presence of the flame prevents the red rays from being
perceived.

The accidental colours developed in experiments like the
last, (3.) Plateau considers as distinguished by particular
properties, different from those pertaining to colours which
succeed the action of coloured light. For, the intensity of
the latter is proportionally greater as the action of the
coloured light is prolonged. The former, on the contrary,
possess all their intensity in a very short space of time, and,
if we continue to look at them, the colour becomes feebler.
Thus, if we hold between a window and the eye a piece
of semi-transparent red paper, upon which a strip of white
card is applied, the small strip will appear of a green shade;
and, if we continue to look at it, the colour will become less
intense. Hence, he concludes, we should beware of con-
founding the two kinds of accidental colours, and that the
existence of the one set does not necessarily lead us to infer
the co-existence of the other set.

9. Having proved, as he conceives, that accidental colours
do not proceed from a moral cause, but originate from a true
affection of the retina ; and, since they can be developed
without any participation of external light. Plateau con-
cludes, 1. That the accidental image results from a peculiar
modification of the organ, by which a new sensation is spon-
taneously produced : 2. He infers, from experiments, that
*' the accidental image is always preceded by the continued
action of the primary image;" 3. " The mixture of two
real complementary colours produces white, and that of
two corresponding accidental colours forms the opposite of
white or black."

1835.] Composition of White Light. 185

4. " These two accidental colours have reciprocally the
the same tints as the two real colours ; they are also com-
plementary, the one to the other : that is to say, they
have the relation of tints which two real colours ought to
have to produce white." Hence, *' since any two real com-
plementary colours form, together, white, any two accidental
complementary colours produce the opposite of white or
black."

5. "In all the cases, where real colours, by combining,
produce white, the accidental colours of the same tints pro-
duce the opposite, or black."

6. Hence, the " accidental impression is of an opposite
nature to the direct corresponding impression.

7. Combining the previ6us results, (1, 2, and 7), it may
be concluded that when the retina, after having been excited
for some time, by the presence of a coloured object, is sud-
denly withdrawn from this excitement, the impression pro-
duced by the object continues to subsist, during a period
which is generally very short ; after which, the retina ac-
quires, spontaneously, a state opposite to its first condition,
from which the perception of the accidental colour results.

8. Anew property is thus admitted in the retina; for,
' " the retina opposes to the action of light a resistance which

increases with the duration of this action, and from which
there appears to us, when we look at an object for a long
time, a progressive weakening in the brightnessof the object.

9. Plateau sums up the substance of his theory as fol-
lows : When the retina is submitted to the action of the
rays of any colour, it resists their action, and strives to
regain its normal state with an increasing force. If it is
then suddenly withdrawn from the exciting cause, it returns
to the normal state, by an oscillatory movement, propor-
tionally great according to the prolongation of the action,
and by which the impression passes, at first, from a positive
to a negative state, then continues generally to oscillate in
a manner more or less regular, while weakening ; some-
times terminating by disappearing and re-appearing alter-
nately ; at other times passing successively from the nega-
tive to the positive state, and vice versa.

The interval which elapses between the instant when the
retina is withdrawn from the action of the coloured object.

186 Proceedings of the British Association for [Sept.

and that when the impression begins to assume the negative
state, constitutes what is understood by the persistance of
the impressions of the retina, and the negative phases of the
impression, form the phenomenon of accidental colours.

Article III.

Proceedings of the British Association for the
Advancement of Science,

This fine Natural Institution continues to prosper far beyond
anticipation. The Fifth Annual Meeting, which commenced
at Dublin on the 10th and terminated on the 15th of August,
as much surpassed the Edinburgh meeting, both in the
interest of the proceedings and in the numbers of indivi-
duals who flocked to take a share in the daily business, as
the latter meeting exceeded that which preceded it. It
is pleasing to be able to prove this assertion, by a statement
of facts: The receipts in Edinburgh were £1,626, while
those in Dublin were £1,750. The number of subscribers
in Edinburgh was little above a thousand : in Dublin, it
amounted to 1 ,228 ; and, it is quite certain that it would
have been much greater, if it had not been that the arrange-
ments of the Local Committee were either not generally
known, or not attended to in time by many residents, whose
applications could not be received after the commencement
of business, in consequence of the great influx of strangers."^
That the capital of Ireland was chosen as the place of con-

* It is easy to complain and find fault, but while we approve highly of the
general arrangements of the Dublin local committee, we cannot refrain from
submitting for the consideration of the Bristol committee, the importance of adopt-
ing a method of giving out Tickets and receiving subscriptions, which shall dis-
pense with the crowding, and fighting we might almost term it, which is unavoid-
able by the mode at present pursued, and which seems to paralyze those engaged
in the troublesome task. It would be proper also that persons should be employed
in these preliminary arrangements, who are acquainted with the names of those
engaged in prosecuting science. It is ridiculous to hear such a question as, " Have
you written any papers?" addressed to men holding the highest place in science.

A great error committed in Dubhn was, in having the gardens attached to the
Rotunda, open during the evening meetings. One of the most curious and
interesting Lectures delivered during the week, viz. that of Mr. Wheatstone, on
Saturday, was not heard by the greater proportion assembled in the room, in con-
sequence of interruption; from persons going to the gardens and returning to the
worn.

1835.] the Advancement of Science. 187

verition for the meeting of this year, we know was hailed by
our hospitable neighbours with those feelings which we
should have expected from the countrymen of such scientific
lights as Robert Boyle, Kirwan, and Brinkley. But that
the reception given to the Members of the British Associa-
tion could have been equal to what each individual member
found it to be, we are confident none could have most
distantly anticipated. If respect to the delicate feelings of
ibur open-hearted friends did not forbid every one who
shared in the kindness which was so liberally exhibited, to
remove that thin veil which ought always to prevent private
hospitalities from being held up to public gaze ; how could
not each of the twelve hundred and twenty-eight members
of the British Association depict innumerable instances of
traits of character, of friendly actions, and of soundness of
principle which could not be exceeded, go where he might:
and must ever be viewed by the philanthrophist, as most
honourable to human nature. The present meeting has
demonstrated that Science is not asleep in Ireland, but that
it is quietly and modestly cultivated, and is ready to burst
forth whenever due encouragement is administered to fan its
kindling embers. That the causes of dissension which have
so long prevailed in the green island may speedily be dissi-
pated, and that the United kingdom and the Sister island
may in future aspire only to increase each other's prosperity
and greatness, was the public expression of some of the
most distinguished leaders, and w^as ardently responded toby
every member of the Association. Let us hope that Science,
which is not sectarian in its nature, which is of no country,
or climate, but which is universal as the principle of gravity,
may tend to heal all chafing wounds, and serve to unite in
the bonds of friendship, all those who are engaged in inves-
tigating her hidden stores, the wonders of creation.

On Monday the 10th of August tickets of admission were
procured by strangers ; those of residents having previously
been obtained, as required by a public announcement.

In addition to most of the British men of science, several
foreigners joined the lists of the Association. Among these
were M. Agassiz, of Neuchatel, and Dr. Moll, of Utrecht,
who were also present at Edinburgh.

At 10 a.m. the different Committees of the Sections began
to meet.

!•§ Proceedings of the British Assoc tatio7i for [Sept.

The Sections were as formerly, six in number.

A. Mathematics and Physics.

Subsection A. Mechanical Arts. This subdivision was
formed in consequence of the press of matter in the depart-
ment of General Physics.

B. Chemistry and Mineralogy.

C. Geology and Geography.

D. Zoology and Botany.

E. Anatomy and Medicine.

F. Statistics.

Geology and Geography — Monday, lOth August.* President,
Mr. Griffith. Vice-Presidents, Mr. Murchison ; Pro-
fessor Sedgwick. Secretaries, Captain Portlock ;
Mr. ToRRiE.
1. The Chairman exhibited a Geological Map of Ireland,
the construction of which had occupied his attention for
many years ; and, although there might be some errors in
matters of detail, he believed that it was generally correct,
and afforded a faithful outline of the physical structure of
Ireland.

One remarkable peculiarity in the physical structure of
Ireland is, that while the waters are almost every where
fringed with ranges of primary mountains, the interior of
the country is level, or slightly undulated, and hence the
course of most of the Irish rivers ; in fact, the Shannon
affording the only exception to this remark.

Another remarkable circumstance in the physical history
of Ireland, is the frequent occurrence of long ranges of
granite hills, often attaining the height of twenty or thirty
miles, and running parallel to each other. In ancient times
roads were constructed on the tops of these natural mounds.
The usual course of these ridges is E. &: W., but occasion-
sionally they are N. & S.

These heaps of granite give an undulatory aspect to the

* To Professor Powell of Oxford, and Dr. Scouler of Dublin, the Editor is
almost solely indebted for the reports of the proceedings of the Geological and
Physical Sections. He is himself responsible for the details relating to that of
Chemistry ; and for the other reports he is obliged to Mr. King of Dublin and
to other sources.

I

1835.] the Advancement of Science: 189

country ; and, it is to this circumstance that the profusion
of ridges in Ireland is owing ; the depressions between the
the ridges becoming receptacles for water, and being after-
wards obliterated by the formation of peat, the result of the
decay of aquatic plants.

It is, of course, beneath this accumulation of peat, and
in the subjacent marl that the remains of the Irish elk are
found. This marl is, in part at least, produced by the granite
previously described, and sometimes attains a thickness of
forty feet.

The speaker then proceeded to consider the stratified
rocks ; first describing the primary tracts which occur to-
wards the coast, and then the vast and level district of
calcareous rocks which occupies almost the whole of the
interior of the island. The elevation of the strata through-
out Ireland is remarkably uniform, being N. E. and S. W.
in almost every part of the island; to this remark, however,
there are some exceptions, as, in the county of Tyrone,
where the elevation of the strata is from N. to S.

From what has been stated, it is obvious that the primary
rocks generally occur near the coast, constituting the moun-
tainous regions of Down, Donegal, Mayo, Galway, and
Wicklow, &c. These regions containing all the usual primary
masses ; as gneiss, mica-slate, clay-slate, and quartz rock,
present in each locality many interesting appearances,
which we have not sufficient leisure to detail.

Quartz rock, however, occurs at Dunmore Head, under
some interesting modifications. It contains abundance of
globular concentric concretions, differing, in no respect, in
their structure from the fibrous masses found in trap, and,
like them, decomposing in crusts.

In Donegal, beds of primary limestone occur, often
alternated with mica slate, and have, in many cases, been
changed into dolomite.

Mr. G. then remarked that his information concerning
the transition formations was less complete. These rocks
consist of the grey wacke and old red sandstone formations.
In Cove of Cork both these are schists containing fossils.

These transition and schistose rocks are succeeded by the
mountain limestone, which occupies about two-thirds of
the whole surface of Ireland. The organic remains found

JdO Proceedings of the British Association for [Sept.

in these calcareous rocks are, in general, the same as those
found in England.

This limestone is succeeded by the coal formation . The
newer secondary strata only occur in the north of Ireland,
where we have the new red sandstone, with gypsum and
beds of magnesian limestone, and these rocks are succeeded
by lias, oolite, and chalk.

2. Dr. West afterwards read an able paper on the geo-
graphy of South Greenland.

Tuesday, Wth. — 3. The Rev. Archdeacon Verschoyle read
an interesting paper on a series of trap dykes which occur
in the counties of Mayo and Sligo.

These dykes are remarkable for the length and distinct-
ness of their course. Their elevation is E. k W. They
are, consequently, parallel to each other, and one of them
has been traced for a distance of forty-five miles. These
dykes, during this long course, intersect a great variety of
rocks, as slate, sand-stone, limestone, mica, and slate, &c.,
and here produced many curious changes, converting the
sandstone into quartz, and even giving it a columnar form.
It was the opinion of the Reverend gentleman, that these
veins, or a series of them, extended across the island. Mr.
Griffith here remarked, that beween Dundrum and Dun-
da,lk, on the opposite side of the island, a great number of
trap veins had been observed.

4. Professor John Phillips next read a paper on the fossil
Astacidae.

The speaker commenced by making some remarks on the
natural history of the genus Astacus. Of the species which
compose the genus Astacus, as at present existing, some are
found in salt and others in fresh water. There are two
empiric characters by which the marine may be distinguished
from the fluveatile Astaci : In the marine species the lateral
divisions of the tail are transversely divided, while in the
fresh water species the division is longitudinal. The marine
species have also large didactylous claws to the first pair
of feet.

All the fossil species possess those characters which be-
long to the marine division. Proceeding to investigate the
question as to the possibility of identifying strata by means
of their organic remains, it was remarked that the study of

1835.] the Advancement of Science. 191

the fossil species of the present genus did not afford results
very favourable to such a hypothesis. Confining our atten-
tion to the oolite and lias, it was observed that one species
of Astacus was found in every bed, from the lowest of the
lias to the uppermost of the oolite.

One species was confined to the coral rag ; four species
were peculiar to the green sand ; some of the species were
more local, and others appear to have had a wider geogra-
phical distribution, as is the case with the Astaci of the
present day.

Mr. Grifi^ith then resumed the explanation of his Geolo-
gical Map, and described the erupted rocks which have
been observed in Ireland. He divided the unstratified
masses into three portions : 1. Those occurring in transi-
tion and primary rocks : 2. In the older secondary : 3. In
the newer secondary.

It was remarked that the limestone which comes in con-
tact with the erupted rocks of the primary division, is often
changed into dolomite.

Green stones occur among the older secondary rocks in
the county of Limerick. These green stone beds are appar-
ently interstratified with the lime-stone, but fragments of
this latter rock are included in the trap.

The trap veins occurring in the newer secondary for-
mations, as in the chalk of Antrim, are already sufficiently
well known. Mr. G. is of opinion that the porphyry of
Sandy rock is merely a modification of the ochre beds which
are observed at the Giants Causeway, as there is a striking
resemblance between the two rocks, in point of mineral
character, and both contain nodules of mesotype.

Wednesday^ \2th. — Mr. Griffith gave anaccount of amass
of shelly gravel in the county of Wexford : this deposition is
very extensive, stretching along the coast for a distance of
seventy miles, and attaining a breadth of eighteen. The
following is a section of this deposit :

5 feet of clay

7 feet marl clay

7 feet marl

7 feet of sand
11 feet of gravel, containing abundance of marine shells.

5. Mr. Phillips then read a paper on the genus Belemnite.

192 Proceedings of the British Association for [Sept.

He observed that such was the progress which the study of
organic remains had made, that no less than one hundred
species were now known to naturalists ; and of these, about
thirty- four species had been found in England.

Shells of this genus are confined to the chalk, oolite, and
lias, and the results which their study affords, contrast re-
markably with the negative indications deduced from an
examination of the fossil Astaci. One division characterized
by a little swelling at the apex, and possessing a lateral
fissure, was confined to the chalk. The species which were
obtusely mucronate are found in the green sand. The
species with a groove in the back are found in the middle
oolite : Those with a lateral groove, in the lias, and lower
oolite ; and those species which are destitute of a groove
are confined to the lias. From these remarks, it appears
that not only are the species of Belemnite confined to cer-
tain strata, but that even certain natural divisions of the
genus are found together in the same beds, and in no others.
Another curious remark is, that species which are common
in the chalk of the Continent, are rare in the chalk of
England, and vice versa.

These remarks were followed up in an admirable manner
by M. Agassiz, who, from a study of the remains of this
difiicult genus, clearly demonstrated that the shell was an
interior one, analogous to the bone of the cuttle fish, and '
not an exterior shell, as is generally imagined.

6. Lieutenant Denham, R.N. , one of the oflftcers attached
to the Ordnance Survey of Great Britain, exhibited ^ map
illustrative of the estuaries of the Dee and Mersey. He
was one of the first to discover, along with his brother
ofiicers, an important channel in the Mersey, after various
ineffectual and expensive efforts had been made to improve
the navigation of that river, an object of the greatest im-
portance to Liverpool. The channel runs North and South,
at right angles to the tide which washes over it. Lieutenant
Denham called the attention of the Section to the half tide
level, as a means of determining the level of the sea and the
land, the main level, or half tide being always constant, the
high tide being variable from various causes. In illustration
of his views upon this subject, he exhibited a chart of the
estuary of the Dee and Mersey, and a tide table, calculated

1836.] ' the Advancement of Science. 193

so, that the mariner may know any half hour the banks
which might be crossed, thus pointing out what was dan-
gerous, and when it ceased to be so, a matter of great relief
to the mariner. Lieutenant Denham complimented the dock
trustees of Liverpool, for their munificent expenditure, in en-
abling him to prosecute his object, and dwelt with particular
energy on the great liberality of Sir John Tobin. Lieutenant
Denham suggested the utility of establishing a half tide
level at each port, to point out the soundings of banks at
the half tide along the continuous shore. He next alluded
to the error which had been nearly committed, in cutting a
canal fi*om Bridgewater to the sea, when there were tides
from a fifty feet level to eighteen feet. He observed, that
if the distance from the earth's centre to the half tide level
was calculated, it would form a correct base for ascertain-
ing the heights of the land. It would form a matter for
consideration if the influence of the sun and moon on the
tides were withdrawn, whether or not the water would re-
-cede to the half- tide level.

Professor Sedgwick congratulated the town of Liverpool
on the importance of this discovery, and the possession of
such a map and tables.

Sir John Tobin offered a few observations complimentary
to the exertions of Lieutenant Denham.

Mr. Griffith moved the especial thanks of the Section to
Lieutenant Denham.

Mr. Murchison said, this showed the intimate connexion
between geology and geography. If this subject was fol-
lowed up with that spirited enterprize displayed by such
gentlemen as Sir John Tobin, and others, the encroach-
ments of the sea in one place, and the increase of land in
another, and the rate of that increase and decrease might
yet be defined.

The communication of Lieutenant Denham is considered
as one of the most important subjects in physical geography
yet submitted.

Thursday^ August l^th, — 7. M. Agassiz laid before the
Association an additional number of his work on fossil fishes ;
and, in an eloquent address, he gave a summary of the geo-
graphical conclusions to which the study of fossil fishes had

VOL. II. o

194 Proceedings of the British Association for [Sept.

conducted him ; and expressed his conviction that strata
might, in ^,11 cases, be identified by means of the remains
of fishes ; or, in other words, that each geological epoch
was characterized by its peculiar and exclusively appropriate
race of fishes.

During this part of the proceedings Mr. Sedgwick took
the -opportunity of putting M. Agassiz's knowledge to a
severe test. He exhibited a specimen containing impres-
sions of fossil fishes, and M. Agassiz, after explaining the
zoological characters which distinguish the fishes of diffe-
rent geological epochs, at once declared the specimens before
him had been derived from the new red sand-stone.

8. Dr. Trail then read a paper on the Geology of Spain.
He confined his remarks chiefly to the province of Anda-
lusia. In this interesting country we have every variety
of rock, from the oldest primary, up to the tertiary strata.
The mica slate of Andalusia contains many interesting
minerals, as iron,, glance, and lead ore. This last mineral
is so abundant that no less than 35,600 tons were ex-
tracted in one year. The primary rocks are succeeded by
secondary sand-stones, in whose fissures interesting osseous
remains occur. These lime-stones extend to the opposite
coasts of Africa. This lime-stone is followed by new red
sand-stone, and gypsum marl, abounding in salt and saline
springs. Oolite rocks occur near the ancient town of
Cartua; and chalk, with flints, is observed at Labriga.
Tertiary and fresh water lime-stones also occur, as has been
noticed by Colonel Silvertop.

The beds at Valencias vary from 6 to 8 feet in thickness,
and repose on^marl and gypsum.

Friday, \4:th August. — 9. Mr. Phillips gave an account
of a small portion of a tertiary formation which had been
observed in Yorkshire.

10. Messrs. Murchisonand Sedgwick then gave an account
of the rocks anterior to the coal, and posterior to the primary
strata. These rocks, which were formerly distinguished by
the absurd term of transition strata, have been, unaccount-
ably much neglected by geologists ; and, unfortunately, the
use of this term has given rise to much confusion in geolo-
gical writings. Mr. Murchison has, for several years,
devoted his time to the study of the older secondary rocks.

1835.] the Advancement of Science. 195

as they occur in Wales, while Mr. Sedgwick has investigated
those of Cumberland.

According to Mr. Murchison, the older secondary rocks
of Wales, which he, for the sake of convenience, denomi-
nates the Silurian group, may be classed under three divi-
sions, each of them containing its peculiar organic remains,
and consisting of a great variety of rocks.

In the descending series, and departing from the old red
sand-stone, we have the Ludlow rocks, attaining to a thick-
ness of 2,000 feet, consisting of crystalline argillaceous
lime-stones, with flags and shales.

These rocks are followed by the Wenlock group, con-
sisting also of limestones and shales. These are succeeded
by what Mr. Murchison has denominated the Caradoc
group, a series of rocks similar to the preceding, and
attaining to a very great thickness.

These formations, however, appear to be newer than the
Cumbrian rocks which have been investigated by Mr. Sedg-
wick, and which he also divides into three subordinate
groups, all of which are included under the name of Cum-
brian rocks. The first, or upper, is the Plinlimmon group ;
The second, or Snowden group ; and, thirdly, a lower group.
The details on this last series of rocks were rather meagre,
but we have no doubt that ample information will shortly
be laid before the public.

Chemistry and Minei^alogy. — Monday^ \Oth August. Dr.
Thomas Thomson, President. Dr. Dalton, and Dr.
Barker, Vice-Presidents. Dr. Apjohn, and Mr. John-
ston, Secretaries. Committee, — Mr. Davy, Mr. Vernon
Harcourt, Dr. Daubeny, Mr. Graham, Mr. Connell,
Dr. R. D. Thomson, Mr. Kane, Mr. Ferguson, Mr.
ScANLAN, Dr. Geoghegan, &c.

The Secretary presented to the Section printed copies of
tables, exhibiting at a single view, the most important
properties of simple and compound bodies, for defraying the
expenses of the printing of which, £10 had been allocated
at the last Meeting of the Association.

1. A paper was then read by Mr. Davy, upon the subject
of the corrosion of iron by sea water. The observations had
particular reference to the injury sustained by the iron of

o2

196 Proceedings of the British Association for [Sept.

buoys, subjected to the influence of sea water in harbours,
as at Kingstown ; where it has been recently found, that the
rings upon which the safety and utility of the buoys mainly
depend, rapidly corrode and are destroyed. Mr. Davy
turned his attention to the important object of providing a
remedy, and preventing the corrosion of the iron ; and al-
though his experiments had only recently been commenced,
still he considered it proper, to bring the few results he had
procured before the Section, for the purpose of exciting
further inquiry. He found that zinc applied to iron pre-
vented corrosion. Rings of this metal were cast into fore-
locks for the purpose of experiment, and were found to
obviate the waste to which the iron had previously been
subject.

According to Sir Humphry Davy, the cause of the corro-
sion of copper, and metals in contact with sea water, is
attributable to the access of atmospheric air. He con-
sidered that if the air was preserved from coming in contact
with the metal, no decomposition would ensue. Mr. Davy
accordingly found, that copper exposed to the action of sea
water free from the influence of air, was not liable to cor-
rosion, and that the effect was influenced by the depth of
water. Specimens of metals were exhibited, which had been
subjected to the influence of salt water free from air, and
no corrosion had taken place ; other pieces of metal which
were in contact with sea water subject to the influence of
air, were observed to be much injured. Mr. Davy attributed
the cause of the phenomenon to an electrical decomposition.

He stated further, that he had found zinc to preserve tin
plate, both in fresh and salt water.

Some observations were made by members of the Section,
with regard to the action of sea water upon bar and cast
iron. Some attributed the greatest corrosion to the former,
others to the latter.

2. Mr. Ettrick described an improvement which he had
made upon Davy's safety lamp, for the purpose of obviating
accidents which are entirely owing to the carelessness of
workmen. The Davy lamp, he stated, to be perfect in
principle. The workmen are in the habit of enlarging the
apertures in the wire gauze, and applying their tobacco pipes
in order to obtain a light. The modifications recommended

1835.] the Advancement of Science. 197

at present, were the introduction of very strong glass, to
cover the gauze externally. The glass is again guarded
by strong ribs of iron, so that the lamp may be exposed to
considerable shocks without danger of injury. A contri-
vance was also described by which the air was allowed to
enter from below, by means of a gauze tube, but so managed,
that the gauze could not be reached by the workmen.

Various improvements upon the Davy lamp were noticed
by different members.

Mr. Graham stated, that he had been paying consider-
able attention to the subject, and had found that when the
gauze was steeped in an alkaline solution, the flame was pre-
vented from passing so readily, and corrosion was obviated.*
He considered the only adequate provision against accident
to be the employment of a double gauze cover.

3. Mr. Kane read a communication in reference to pyr-
oxylic spirit. The experiments which he had made upon this
substance, corroborate the opinion of its composition enter-
tained by Dumas and Pelligot, who term it methylene, viz.
that it is a compound of an atom of carbydrogen, and 1 atom
water, having for its atomic weight 2. He had examined
the action of sulphuric acid upon the liquid, and had ob-
tained by distillation, an acid capable of forming salts with
bases. The composition of several of these, he had ascer-
tained by determining the proportions of the acid, (or sulpho-
methylic acid) and base, and considering the loss to be me-
thylene. The compound with lime, consisted of 1 atom lime
4- 2 atoms sulphuric acid + 1 methylene.

Some discussion took place in reference to the double
atoms, of which the organic bases are stated to consist,
according to the views of Continental chemists. Consider-
able misunderstanding was exhibited in many of the obser-
vations offered upon this point. But it is unnecessary to
repeat the statement of the various theories, as this has
been already done in the previous number of this journal,

4. Mr. Fox described an experiment which he had made,
with regard to the effect of melted iron upon the magnet.
He found that no action was exerted upon it. Hence, this
is an argument against the idea of a central fire.

* Tliis is agreeable to the results obtained by Dr. Thomas Thomson many
years ago.

198 Proceedings of the British Association for [Sept

5. A letter was read from Dr. Turner, reporting the opi-
nion of the committee appointed at last meeting, to take into
consideration the adoption of a uniform set of chemical
symbols for this country. The opinion of the majority was,
that those used on the continent should be had recourse to.
It was strongly recommended that the abbreviations should
not be carried further than the dots for oxygen ; indeed, it
was suggested by some, that these should be rejected, as
they merely express theory, and consequently vary, accord-
ing to the view that is taken of the composition in this
country and on the continent ; but it is obvious, that if
brevity is not carried any further than this, no bad conse-
quences can follow from a system of notation.

Dr. Thomas Thomson strongly recommended that the
centigrade thermometer should be adopted in this country
for scientific purposes, as being infinitely better adapted for
such purposes than that of Fahrenheit. His suggestion
appeared to coincide exactly with the opinion of the com-
mittee.

Tuesday, Wth August. — 6. Mr. Davy detailed some experi-
ments which he had made upon the preservation of tin plate
by the agency of zinc. When exposed for some days to the
action of water, the plate by itself soon becomes slightly
corroded, but is completely preserved by the zinc, the latter,
at the same time oxidizing. Hence, the plate might be
employed in place of copper for many purposes, where
salt water comes in contact with vessels. Several metals
he had ascertained are not protected.

7. Mr. Graham described the constitution of certain salts
in continuation of the papers which he has published upon
this subject. He views sulphuric acid as a sulphate of water,
and as represented by H S. Sulphuric acid of spec. grav.
1*78 is hydrous sulphate of water, or a hydrate expressed
by H S H, 1 atom being basic and essential to the composi-
tion of the acid, the other being driven off" by heat. Hy-
drated oxalic acid is an oxalate of water H (C + C) H^.

Nitric acid = H N' H^ of spec. grav. 1-42.

Oxalate of magnesia =Mg (C + C) H^.

Nitrate of Copper = Cu N H ^ .

There are three oxalates of potash,

l.K(C + C)H.

1835.] the Advancement of Science. 199

2. K (C +' C) H (C + C) HS or binoxalate ; decomposes
at 300° and loses 2 atoms.

3. K (C + C) H ^ H (C + C) H2

c H (C + C) H2 or quadroxalate, the 2
atoms of water in the binoxalate being replaced by hydrated
oxalic acid.

There are two remarkable salts, which correspond with
each other in composition, viz., oxalate of potash and iron
which is green, although the iron is in the state of per-
oxide, being precipitated red by potash, and the oxalate
of potash and chromium which is dark coloured. The
first is represented by Fe (C + C)^ 3 K (C + C) + H^.

If we substitute chromium for iron, we have the compo-
sition of the chromium salt.

The same law in reference to water, it is probable, is
generally applicable to the composition of the carbonates.
Carbonate of magnesia is represented by Mg CH^. At
212° the water is expelled.

Bicarbonate of potash =K C H Cis a carbonate of potash
and a carbonate of water, because the latter can be readily
driven off. Two additional atoms of water may exist in it.
The bicarbonate of potash and magnesia of Berzelius, has
the same composition as quadroxalate of potash, the symbol

being K C H C f M^- 9 ^"^ ^ + H* making 9 atoms of water

in the salt, and the magnesia occupying the place of the
water in the quadroxalate of potash.

Rose described a class of salts formed by the absorption
of dry ammonia. He considered the ammonia not to act
as a base, but to take the place of water.

Mr. Graham coincides with him in opinion. The compo-
sition of ammonia may be represented byNH^NH^HO,
being analogous to sulphuric ether, which consists of 2 atoms
olefiant gas. The nature of its function maybe observed
in the composition of the common sulphate of copper and
ammoniacal copper, the first is, Cu S H + H^, the second
Cu S H + (N H3) 4 the ammonia taking the place of the
water. There are 2 ammoniurets, 1 containing 4 and the
other 5 atoms of water.

8. Mr. Johnston made some observations on the optical
properties of chabasite, in reference to those made by Sir

200 Proceedings of the British Association for [Sept.

David Brewster at last meeting. Sir David found that this
mineral possesses different refracting povt^ers at different
depths of the crystal, and he concluded, that it consisted
of distinct layers, and that 'if subjected to experiment it
would afford the result of a compound substance. His re-
sults refer to particular species only ; but the composition
of the species vary, and are as represented here
C

+ 3 AS2 + 6 Aq.

where Mr. J. conceives that it is easy to see the cause of
the difference, for the refractive power of chabasite is posi-
tive, and that of quartz negative ; thus accounting for the
double refracting power observed by Brewster.

Dr. Thomson remarked that the observations of Brewster
probably referred to one species of chabasite. But there
are two species, the one containing soda and the other lime
as a base. He, therefore, considered that until both species
were examined, no inference whatever could be drawn.

9. Dr. Daubeny stated, that according to the opinion of
Von Buch, carbonate of magnesia must have been sublimed
in many instances by volcanic action, although as far as
Dr. Daubeny was aware, it was not agreeable to the results
of chemists. A curious fact illustrative of the truth of Von
Buch's opinion, occurred to Dr. Daubeny in Italy. He
visited a locality where there was an upper stratum of lava,
containing cavities. In one of these Colonel Robinson dis-
covered a large quantity of carbonate of magnesia. Dr.
Daubeny found a quantity coating the upper surface of the
lava.

Dr. Dalton observed that there could be no doubt as to
the sublimation of carbonate of magnesia, as Dr. Henry had
informed him that a quantity of this salt was always driven
off whenever the heat was carried beyond a certain height.

10. Dr. Dalton stated the results of his examination of
the spirit distilled from caoutchouc. He found it to depress
the barometer like sulphuric ether. It passes through
water without diminishing its volume, thus differing from
ether. It is absorbed by water like olefiant gas. It con-
sists of 2 olefiant gas. 10 vols, when burned give 40
carbonic acid, and require 60 of oxygen. It appears to
be the same as a substance described by Faraday. It differs

1835.] the Advancement of Science. 201

from coal gas in this, that the latter consists of double
defiant gas.

The observations of Mr. Davy upon this subject corre-
sponded with those of Dr. Dalton.

Wednesday^ August \2th. — 11. Mr. Mallet described the
phenomena presented in lamps, when the holes for the passage
of the gas are made as small as possible, and also the ap-
pearance observed when the direction of the tube is inclined
in different ways, two currents being formed when the tube
is inclined, and the surface of the flame presenting spiral
lines, and considerable retraction of the flame taking place,
none, however, occurring when the tube is not fully in-
serted. The apertures in the lamp were less than the ^J^ of
an inch in diameter.

In the discussion which arose from this communica-
tion, Dr. Dalton observed, that 12 small holes in a lamp
consumed less gas and gave more heat than when the holes
were larger but fewer in number. But the great object in
procuring a proper quantity of heat depends upon the atmos-
pheric air being neither too great nor small in quantity. He
stated, that if we take a cubic inch of pure gas, and another
diluted with half its volume of air, each gives out the same
quantity of heat, but the latter scarcely yields any light.
This is an important fact, and deserves to be known.

12. Mr. Connell read a paper in which it was his object to
point out some chemical facts, by which we maybe enabled
to detect, whether a fossil scale be that of a fish, orsauroid
animal, and illustrated his position by some analyses which
he had made on recent crocodile and fish scales, and upon
the scales found at Burdie House. His inference was,
that chemical analysis completely verified the idea of
Agassiz, that the scales found at Burdie House were those
of fish. He considers the animal matter to be replaced
by a little carbonate of lime and silica.

13. Mr. Kane described two compounds of tin and plati-
num formed by the action of protochloride of tin upon a
solution of platinum. One of these compounds consists of
an atom of each chloride. It deliquesces in the air; is a
dark solid substance when anhydrous, and when allowed to
remain in the air is converted into an olive liquor, which is
resolved into the oxides by the action of water. The author
suggested that tin affords a good test for platinum.

202 Proceedings of the British Association for [Sept.

14. Mr. Snow Harris exhibited an apparatus or modified
electrometer, for performing the experiments of Pouillet,
by which the insulation of the gold leaves is rendered in-
dependent of the glass, by means of two rods, terminating
in gilded balls. To determine whether electricity is deve-
loped during the evaporation of water or any liquid, a
platinum crucible containing the substance to be examined,
is placed upon the cap of the electrometer, having one of
Deluc's small piles communicating with the rods. His re-
sults were contrary to those of Pouillet.

15. Dr. Newbigging made some observations upon an
experiment which he had made with regard to the colour
of arterial blood. He placed some blood in a cup containing
green spots on its surface. The portions opposite to these
spots assumed a vermilion colour, but in no other part was
this change visible.

Thursday, \3th August. — 16. Mr. Hartop made some ob-
servations on the effect of the hot air blast, when applied to
the manufacture of iron. He opposed some of the state-
ments made by Dr. Clark at the last meeting of the Associa-
tion, relative to the increase in the product and the quality
of the iron ; the former having been overrated, and the latter
being decidedly inferior, as far as Yorkshire was concerned.

17. Dr. Apjohn explained a formula for ascertaining the
specific heat of gases ; the expression being
/.//_ /./ ^Sad p
^ "J T~ "" 30
He has found it to correspond almost exactly with experi-
ment. He modifies it to

. (f'-f")e 30
48 (i p

If the air be quite dry, the/" (which expresses the elastic
force of vapour at the dew point) will be unnecessary, and
the formula becomes

48rf ;?
The experiments were made by means of a syphon with
short horizontal arms. Sulphuric acid was introduced into
the legs. Two bladders, the one filled with common air,

* These formulae are elucidated in a paper in the last Volume of the Trans, of
Che Irish Academy.

1835.] the Advancement of Science. 203

and the other with the gas to be experimented on, were
attached to one of the arms, and two thermometers, the
one with a moist bulb, and the other dry, were introduced
into the other leg. The bladder was then pressed, and the
air forced through the acid. It passed over the thermo-
meters, and gave the temperature of the gas at the dew
point. This enabled the value of a to be determined, or the
specific heat. A correction was made for the impurity of
the gas, which was transmitted over mercury and analysed.
Most of the experiments corresponded with those of the
French chemists, except in one or two instances. The
general result obtained was, that under equal weights, the
gases have the same specific heat ; and, under equal vo-
lumes, the specific heat is proportional to the specific gra-
vity, except with hydrogen, which, under equal volumes,
has double the specific heat.

The results are represented in the following table : —

SP. HEAT, VOLUMES.

Air .... . 1-000

SP. GR.

1^000

SP. HEAT,

1-000

Azote .... -961^

0-0694

•9877

Hydrogen . . . ^1315
Carbonic oxide . 1*0508

•9722
•9722

1-8948
1-0808

Carbonic acid . . 1*667

1-5277

1-0916

Nitrous oxide . . 1*5277

1-5277

M652

«=fex

30
P

18. Dr. Dalton introduced the subject of a system of che-
mical symbols, by explaining his ideas respecting the com-
position of the simple compounds, and exhibited the expres-
sions which he proposed many years ago, to give a pictorial
view of the mode in which the atoms are collocated. He
consid'ers the composition of nitrous oxide to be 2atoms azote,
adopted by Berzelius, who has not stated from whom he
obtained it. defiant gas, he considers, is composed of
single atoms of carbon and hydrogen, while the gas which
exists in coal, though commonly termed olefiant gas, is, in
reality, double olefiant gas, and is termed by Dr. Dalton,
bin-olefiant gas. This is proved by its affording twice the
quantity of carbonic acid, and requiring twice the quantity
of oxygen, to burn it, which olefiant gas requires.

Mr. Whewell observed that the atoms might as well be

204 Proceedings of the British Association for [Sept.

supposed to be arranged in lines, as in the mode represented
by Dal ton, which was objected to by the latter, as being a
tottering equilibrium.

Mr. Babbage recommended the publication of tables, re-
presenting the composition of substances by symbols,"^ with
the addition of the different weights which have been
brought forward, but without giving the sanction of the
Association to them. He considered it proper that the
algebraical formulse should be adhered to as far as possible.

19. Mr. Mallet shewed a beautiful white material prepared
from turf, which was declared by a paper-maker to be per-
fectly fitted for the manufacture of paper. The upper
stratum of turf, which covers immense tracts in Ireland,
consists of layers. It is acted on by water to separate the
leaves; then by caustic potash or soda; then by an acid.
It is then bleached by chloride of lime. During the process
a substance is obtained possessing the odour of camphor,
mixed with that of turpentine, which is fluid at 290° F.
The upper stratum of turf may also be employed for mill
boards, after being soaked in glue and pressed by a hydrau-
lic press.

Friday, lAtli August. — 20. Mr. Davy described some ex-
periments which he had made in reference to the relative
values of Virginian and Irish tobacco. He procured nicotine
by simply digesting the leaves in potash, and then distilling.
A liquid possessing uniforiA qualities passed over. The
liquid is acted on by acids, affording salts possessing a
sharp biting taste. The effect of the liquid was tried upon
different animals, and found to be highly narcotic. He
found that 1 lb. of Virginian tobacco was equivalent to 2 J
of Irish tobacco ; the root containing 4 or 5 per cent, of
nicotine. The usual estimate of the relative values, by
dealers, is as 1 to 2.

21. Mr. Scanlan detailed the experiments which he had
made upon what he considered a new fluid, prepared from

* Berzelius is erroneously considered to Lave first introduced the use of letters
to express briefly the composition of bodies. Dr. Thomson adopted this method
in one of the earliest editions of his System of Chemistry, where he classified
minerals according to their chemical composition. In his paper on Oxalic
Acid, published in the Philosophical Transactions for 1807, he employs formulas
of this kind. Berzelius indeed, has owned, that he borrowed the idea from
Dr. Thomson.

1835.] the Advancement of Science, 206

pyroligneous acid by saturation with lime, distillation and
purification by charcoal. He found its boiling point to remain
steady at 130°. The following table exhibits its peculiari-
ties when compared with pyro-acetic and pyroxylic spirits.

Sp. Gr. Boiling Point.
Pyro-acetic. . , -828 150°

Pyroxylic . . . -750 140°

New Fluid . . . -906 130°

Another fluid was obtained likewise which appeared to
be new, exhibiting a strong action with caustic potash. It
was suggested, that the first fluid was acetate of methylene,
the specific gravity of which is '919 and the boiling point
136°. The arguments of Mr. Scanlan were admitted by
the Section to be conclusive, in favour of the substance being
distinct from pyro-acetic, or pyroxylic spirits.

22. Mr. Moor mentioned a curious circumstance in refe-
rence to the corrosion of lead pipes. The worm of a still used
for preparing medicated waters, was exhibited, which was
corroded completely through its substance, at those points
where it had been supported with wood and tied with twine.
At these points a black substance was formed, consisting of
oxide and chloride of lead. It was obvious that the effect
was to be attributed to galvanic action.

23. Dr. Barker described a new mode of separating the
peroxide of iron by means of acetate of potash. The latter
salt, when added to a solution of per-salt of iron, precipitates
the peroxide when the liquid is boiled. This would appear
to afford an elegant method of separating iron from manga-
nese.

He made an observation relative to the precipitation of
magnesia by phosphate and carbonate of ammonia: viz.
that the same precipitation takes place with bi-carbonate of
potash, and other salts.

24. Dr. Geoghehan suggested the advantage of employing
the double salt of iodide of potassium and bicyanide of mer-
cury, for the purpose of detecting muriatic acid in prussic
acid. Sulphuric acid is frequently met with in prussic
acid, but the distinction between these two acids is readily
made, by means of nitrate of barytes. The peroxide of
mercury usually employed for testing the purity of prussic
acid is ambiguous in its action, as it is usually impure. The

206 Proceedings of the British Association for [Sept.

use of this salt is not applicable to the alcoholic prussic
acid.

25. Mr. Johnston made some observations on the iodides
of gold, which he had analyzed. Their composition is similar
to the chlorides. Previous errors, he found, were to be
ascribed to the precipitation of an excess of gold, when
ammonia was employed in the analysis.

There are three compounds, viz. (1.) Au I ; (2.) Au 3 I ;
(3.) Au 3 I 4- K I, the atom of gold being 25.

26. Dr. William Barker made some observations on the
passage of electricity along a platinum wire. Black spots
were observed at regular distances, the rest of the wire
being luminous.

27. Mr. Scanlan exhibited a beautiful specimen of hema-
tine crystallized in the centre of a mass of logwood.

Mathematics and Physics. — Monday, \Oth August. Dr.
Robinson, President; Mr. Baily, Sir T. Brisbane,
Vice-Presidents ; Prof. Wheatstone, Prof. Hamilton,
Secretaries ; Prof. Mosely, Mr. Whewell, Prof. Lloyd,
Dr. Drummond, Dr. Knight, Mr. Murphy, Mr. G.
Rennie, Prof. Stevelly, Mr. Cooper, Mr. Wharton,
Dr. Lloyd, Mr. Maccullagh, Mr. Sadlier, Mr. Fox,
Mr. Snow Harris, Prof. Powell, Dr. Dalton, Lord
Adare, LoRDOxMANTOWN,Capt. Sabine, Prof. Babbage,
Dr. Lardner, Col. Colby, Sir J. Franklin, Capt. James
Ross.

1 . Mr. Whewell read his report on the state of our know-
ledge respecting the application of mathematical and dyna-
mical principles, to magnetism, electricity, heat, &;c.

He observed that Newton's anticipation that all physical
forces are to be explained by some application of the princi-
ples of dynamics, is verified by the subsequent progress of
science, and that the only legitimate theories of heat, elec-
tricity, magnetism, &c., are such as are founded on nume-
rical results, reduced to laws. This has been, in a great
measure, accomplished ; and, therefore, mechanical reason-
ing is applicable.

He then compared the two theories of electricity, notic-
ing the application of the higher analysis by Poisson, Mr.
Snow Harris's valuable numerical results, Barlow's Laws of

1835.] the Advancement of Science. 207

Magnetism, and Bonnycastle's Mathematical Theory, which
agrees with experiment, and with Poisson's theory, applied
to magnetism.

He appeared to consider that theory untenable, which
supposes the existence of one fluid only. He brought for-
ward examples of the distribution of the electric fluid on
the surfaces of solids of different forms, which were readily
accounted for, on the theory which assumes the existence of
two fluids. In connexion with this subject, allusions were
made to some statements and experiments of Mr. Harris,
presented to a former meeting of the Association. Mr. W.
shewed that similar objections were made to that magnetic
theory which required the admission of one fluid only, but
that these were not applicable to a theory founded on the
supposition of two fluids.

Mr. Harris explained, and endeavoured to show that
there is no law for the diffusion of the electric fluid on
surfaces of different forms, or of different sizes. He illus-
trated his position by reference to the loaded Leyden jar,
which receives exactly the same charge, whether it is in
part filled with a metallic body, or is simply coated with a
film of metal on its inside. He also pointed out the fact,
that the quantity, or size, or shape of the metallic rods
outside the jar, has no influence on the charge, which is
found concentrated on that part of its surface which is
nearest the glass. Mr. H. applied the same principles to
explain the nature of the charge on air. Several members
expressed their opinions for and against both views. It was
admitted that Coulomb's theory of diff'usion is true in a
perfectly imaginary case, but that, in practice, it never can
be exactly true, on account of the pressure of surrounding
bodies, all of which exercise a greater or less influence in
concentrating the electric fluid on that portion of the surface
which is opposite to each.

The charge of the intervening plate, it was observed, was
independent of the conductors, and the amount of electricity
in a body cannot be ascertained but by bringing another body
towards it. Hence, the results are uncertain. Mr. Whe-
well replied, that the same results were obtained when the
connecting body was different ; and, therefore, the experi-
ment was not liable to uncertainty.

208 Proceedings of the British Association for [Sept.

2. Mr. S. Harris explained and exhibited to the Section,
a new species of instrument of extreme delicacy for mea-
suring electrical forces. It is of the same kind as the torsion
balance of Coulomb, and similar to it in general appearance,
but the peculiarity is this : instead of a needle suspended
by a single wire or fibre, which fibre undergoes the torsion
against which the antagonist force of the electrical repul-
sion is to act, the needle is here suspended by two parallel
fibres run together, one on each side of its centre ; and the
effect may be most shortly described, by saying, that nei-
ther of the fibres undergoes torsion, but the plane (in which
they both lie when at rest) undergoes torsion, or is twisted
into a surface of double curvature. The degree to which
this is carried, is here counterbalanced by a weight; or
gravity thus constitutes the antagonist force, instead of the
resistance of the fibre to torsion, in Coulomb's construction.
It is difficult to give the contrivance a good descriptive
name, since that of torsion-balance cannot be applied, but
of its extreme sensibility and accuracy, no doubt can be
entertained. There are also several very ingenious improve-
ments in the mode of arranging the indices and reading
off from the scale, but these are independent of the peculiar
and beautiful principle above described, and could not be
rendered intelligible but in detail. It is to be hoped the
author will give such details to the public.

3. Professor Powell read an abstract on certain points
connected with the recent discoveries relative to radiant
heat.

The object of his communication was to state, that the
author felt particular satisfaction in observing, that M.
Melloni, (in his second Memoir) describes a repetition of
the experiment originally made by him, and recorded in the
Phil. Trans, for 1825 with perfect success, by means of his
extremely delicate apparatus. The confirmation is the more
complete, as M. Melloni appears to take up the inquiry
with a different object.

It is thus now established beyond question, that lumi-
nous hot bodies are sending out two distinct sorts of heat,
or two distinct heating agents, at the same time, differing
in their properties and mode of operation.

Hence, the whole series of results of M. Melloni must

1 835.] the Advancement of Science, 209

be interpreted with reference to this distinction; and
possibly the consideration of it may remove some of the
apparent anomalies.

And further, if the distinction which he established in the
case of luminous hot bodies do really continue to exist, (as it
seems it must do unless there be a breach of the law of con-
tinuity) at temperatures below that of visible luminosity,
(itself a very undefined point) then it ought to be rendered
manifest by a careful repetition of the same fundamental
experiment, with very delicate thermoscopes, (either Mel-
loni's or such as that used by Dr. Hudson) by which a
smaller, though probably very minute difference of ratio,
would be found in the effects on a black and white thermo-
scope, with and without a glass screen.

Should this be found to be the case, in all cases of reflec-
tion, polarization, &c., with non-luminous sources, it will
henceforth become necessary to distinguish to which of the
two heating causes they belong ; every analogy would lead
us to suppose they belong essentially to that of the two
heating agents which is so closely associated with the light,
that it seems rather a property of the light than any sepa-
rate agent. The length of the undulations which Professor
Forbes has shewn may by analogy be calculated, would be-
long to this species of radiant heat, and be simply such
undulations in the setherial medium as are too large to
affect our visual organs ; whilst the other portion may
very probably be as Sir J. Leslie conjectured, merely a
conveyance of heat by the air ; this would agree with what
is observed of its rapidly diminishing as the distance in-
creases, and being incapable of permeating screens except
by conduction : this, perhaps, may account for the irregu-
larities found by Sir J. Leslie in the position of the forces
of a reflector for heat. Whereas the other sort is conveyed
unimpaired to the same distances as the light, and only ex-
cited when it is absorbed. A vacuum absolutely perfect, de-
monstrably, can never be formed with the air pump, and the
torrecellian, even if free from air and the vapour of mercury
is not large enough for satisfactory experiments, but even
if it should be contended that the radiation through vacuum
has been proved, we must now say to which sort of he^t it
applies. By this distinction the theories of Leslie, De la

VOL. II p

210' Proceedings of the British Association for [Sept.

Roche and others, may very probably be brought into
accordance, since they were perhaps, not always speaking
of the same thing, when they spoke of radiant heat.

Another question of importance which has occurred to
the author is this : whether, in the polarization apparatus,
supposing one glass, or pile of mica, heated, it will radiate
the same quantity of heat to the other in the two rectangular
positions 1 The question is purely a mathematical one, and
has been in some degree considered at the author's sugges-
tion by Mr. Murphy of Cambridge ; the integration has not
been completed, but Mr. Murphy thinks it clear that there
will be a difference.

4. Dr. H. Hudson read a paper on the phenomena usually
classed under the denomination of radiation of heat.

He exhibited experiments with the reflecting and differen-
tial thermometer, to illustrate the radiating powers of
surfaces, interposing occasionally screens with plain and
coated surfaces. He tried the diathermancy of rock salt,
and shewed several experiments with Melloni's thermo-
multiplier, in which the effects were much smaller than
those of Melloni.

5. Captain Sir John Ross detailed a new theory of the
aurora borealis, founded on seventeen years observation.
He observed, that the aurora was always found near the
earth, and he explained its appearance, by the reflection of
the sun's rays on a mass of polar ice, and from thence on
the clouds. He stated, that he had succeeded in finding
rules for correcting the local attraction of the ship on the
needle.

6. Mr. Robert Mallet on an economic application of electro-
magnetic force to manufacturing purposes. The object in this
proposal is, to accomplish the separation of iron filings
from other materials, such as brass and copper in engine
manufactories, iron foundries, &;c., by means of bars ren-
dered magnetic by electro induc^on, and deprived of it by
breaking the connexion.

Tuesday, Wth August. — A communication was read from
Colonel Colby, respecting the Ordnance Survey, accom-
panied with a specimen.

7. Mr. Whewell continued his report ; he noticed the law
of cooling, the geometrical progression, which is only correct

IBSdiJ the Advancement of Science. 2\\

for low temperatures not for higher ; the comprehensive
formula of Dulong and Petit deduced from exact experi-
ments; the application of Libri to various cases ; the mathe-
matical theory of Fourier ; the exchange of temperature,
their mathematical consequences and application to the
theory of the earth ; he made of all these to bear upon
geological phenomena, internal heat, and the peculiar high
temperature of the earth.

8. Dr. AUman explained his theory of a geometrical con-
nexion between the elementary cells and tubes of plants,
and their more complex organs, illustrating his views by
models. He traced a mathematical arrangement in the
different parts, and proposed some theoretical laws of their
distribution.

9. Mr. Snow Harris on the nature of electrical attraction
with experiments. The author is of opinion, that neither
the theory of one nor of two fluids, explains all the pheno-
mena of electrical attraction and repulsion. He makes
exceptions to the law of the inverse square of the distance,
as much depends upon the state and circumstances of the
bodies as evinced by delicate experiments. He exhibited
his apparatus for measuring the force of attraction between
electrified plates and spheres. Some observations made by
Professor Powell and Mr. Whewell shewed that plates will
attract nearly as the inverse distance of the molecules at-
tract in the inverse square. Mr. S. Harris explained, and
remarked, that it was not his object to refute the theory of
Melloni, or the law of the inverse square of the distance, but
that his views were perfectly consistent with facts, and
enabled him beforehand to estimate the degree of the at-
tractive focus acting on substances of all shapes, at all dis^
tances, by conduced and induced electric action. Professor
Stevelly made some remarks to reconcile theory with ex-
periment.

10. Dr. Reid read a paper on the form and construction of
buildings intended for public assemblies, and on the com-
munication of sound in them ; interruption of the unity of
tone was the great source of confusion or loss of sound in
buildings by reverberation. He illustrated his views of the
propagation of sound, by several facts not generally known,
from which it appeared that the subject is as yet but little

p 2

212 Proceedings of the British Association for [Sept.

understood. He gave one instance of ihe sound of artillery
having been heard at the distance of three hundred miles,
and volcanic explosions at a much greater distance. He
recommends that the floors and walls of all large rooms, like
the house of commons, where it is necessary to preserve the
tone and enunciation of the speaker, should have their walls
concave within, with inclined sides, and as low as possible,
so as to diminish the reflection of sound or echo, and made
as rough as possible, by ornaments or other means. He
stated an example of the benefit of studding walls, and
covering them with canvas. He illustrated his doctrine by
reference to the choir of St. Patrick's Cathedral, in which
the enunciation is extremely clear. The disadvantages of
the Rotunda for public speaking were explained, as well a&
the cause of the sensation felt by a person who endeavours
to speak exactly in the centre of the room. Several obser-
vations were made by different persons illustrative of the
author's views, from all of which it followed, that the lower
and rougher the walls, the less their effect in injuring the
intonation. Hence, the propriety of fluting, or fretting
walls of rooms intended for public meetings ; and, for the
same reason, the floor should be also roughened by car-
peting, or sand, or turf mould, or saw dust, or some such
material, which would, as it were, absorb the sound re-
flected from the ceiling, which would be made to act as a
sounding board, to give " body" to the voice. The air
should be preserved in an equable state and currents avoided;
pillars are not injurious. His views appeared to be very
generally approved of.

Professor Stevelly mentioned a curious echo in Trinity
College, Dublin, from iron palisades. Mr. Addams and
Dr. Reid in reply said, the great principle was to avoid re-
flection in sound. Mr. Addams mentioned cases of the
utility of pilastres and other breaks.

1 1 . Mr. J . Russel gave a short account of his experimental
researches into the laws of the motions of floating bodies.
He detailed experiments on two canals in Scotland. He
shewed that small models are not applicable for exhibiting
the resistance of large vessels, the distinction between the
conditions of a floating and an immersed body, with the dif-
ferences from any theory, and that resistance diminished with

1835.] the Advancement of Science, 213

great velocities. He exhibited a table of results, and de-
duced from it that the difference in different canals accord-
ing to size and depth, is dependent on the velocity of the
wave raised. A member stated that the results are con-
firmed on two canals in Ireland, but gave a somewhat
different explanation. Another member confirmed the
results.

Wednesday, \2th August. — 12. Mr. Pritchard exhibited
some experiments on polarization, this morning before the
meeting; they consisted chiefly of improvements in the
mode of exhibition. The most singular fact shewn was, the
formation of a certain white elliptic ring, by light passing
through calcareous spar.

13. Mr. Snow Harris on the use of the proof plane, and tor-
sion balance of Coulomb and others. He detected consider-
able differences in the distribution of electricity in different
parts of bodies, and obtained results, apparently at variance
with Poisson's theory. He compared various theories, and
exhibited experiments in support of his views. Mr. Whe-
well made some remarks on the experiments of Mr. Harris,
and on the utility of theories to assign causes. He differed
from Mr. Harris as to the inferences from the experiments,
and showed, that many of the supposed exceptions are really
quite accordant with the mathematical theory.

14. Captain Sabine gave an account of Hansteen's re-
searches on terrestrial magnetism, who had collected obser-
vations on the variation of the needle in different parts of
the globe, and demonstrated that there are two magnetic
poles in each hemisphere. He exhibited maps of the varia-
tion at different dates, and shewed that the line of no dip was
not a great circle but inflected. He noticed the excursion
of Hansteen to determine the magnetic poles, and variation
in Siberia, the observations of Captain Ross and others,
and concluded by remarking, the absence of any data for
determining the position of the southern pole.

15. Professor Wheatstone examined with a prism the line
of light formed by the voltaic spark between charcoal
points. The spectrum was complete without interruption,
but marked by certain lines of more intense brightness.

With the electric light from a surface of mercury, a few
very bright lines of definite colour appeared separated by
wide dark intervals.

S&^ Proceedings of the British Association for [Sept.

The same light from different metallic surfaces gave
similarly interrupted spectra ; the divisions being distri-
buted in a peculiar manner in the spectra for each metal.

In alloys and compounds of different metals the lines
pe^culiar to each wire were compounded.

The voltaic light from a surface of mercury, and of other
metals in succession, gave analogous results.

At different points of the connecting wire the light ap-
peared of different colour ; that colour was found marked
with a peculiarly bright line in the corresponding spectrum.

High characteristics afford the means of distinguishing
the different metals, and to determine the origin of the
electric light in different cases.

The light from combustion of metals gave uninterrupted
spectra ; thus shewing, that voltaic light is not related to
combustion.

The light of the electric spark from contact of different
metals, gives similar light and dark spaces to those in the
voltaic.

Mr. W. applies these results to the theories of electric
light, and thinks they point out the volatilization of pon-
derable matter from the conductors as the most probable
hypothesis.

16. The Rev. Mr. M'Gauley exhibited and explained a
new principle, consisting in the application of magnetism
as a moving power. The apparatus consists of two powerful
electro-magnets, so arranged that the contact is alternately
changed from one pole to the other, and the poles of the
magnet thus reversed. This produces an alternate motion
in the bar connecting the poles, which moving a crank turns
a wheel and any machinery connected with it. The inven-
tor has succeeded in thus getting a moving power nearly
equivalent to the lifting power of the magnet.

The main peculiarities may be thus stated :

1. The reversing apparatus easily applied, without almost
sensibly altering its weight, to any number of electro-
magnets.

2nd. The connexion of the reversing apparatus with the
vibrating bar.

3rd. The direct application of the entire, or nearly the
entire lifting power to machinery.

1835.] the Advancement of Science, 216

4th. The action of several electro-magnets without their
interfering with each other.

17. Mr. R. W. Fox on a new dipping needle. The instru-
ment which shews, at once, the dip, intensity, and variation,
was exhibited. It contains graduated circles, moving in
altitude and azimuth, and a vertical index adjusted to meri-
dian, turning in azimuth till the needle is vertical. Hence,
the dip may be deduced, and the intensity, by comparing
the effect of a small magnet introduced.

Professors Stevelly and Lloyd made some remarks.
The accuracy of the instrument was confirmed by the
testimony of Sir John Franklin, who had examined it in
connexion with Messrs. Christie and Barlow, even under
extreme conditions.

18. Professor Hamilton on the theory of Logologues, and
other numbers of higher orders. He discussed the nature of
algebra, and whether it is to be considered a science or only
a language? His leading idea is, that it may be regarded
as the science of pure and abstract time, as geometry is the
science of pure space ; and that the distinction of positive
and negative corresponds to past and future. He regards
imaginary quantities as couples of moments, or couples of
steps : a given moment as having a given position, in regard
to time, as a given point in space : each step has direction
and magnitude. He referred to his paper in the Irish Trans-
actions, which contained his suggestions for certain improve-
ments and simplifications in algebra.

Thursday, 13/A August. — Mr. R. Roberts exhibited an
apparatus by which figures may be seen, or sentences read,
as distinctly, when revolving at a high velocity, as when in
a state of quiescence. It illustrates, also, the duration of
light on the eye.

19. Mr. Baily read his report on the Aberdeen Standard
scale of 3 feet, which was compared with that of the Astro-
nomical Society, by the recommendation of the Association.
He found a small difference, and concluded with some
suggestions for the better construction of such scales.

Sir Thomas Brisbane remarked the necessity of attending
to expansion. Professor Stevelly made some observations
on the same point, to which Mr. Baily replied, by stating
the precautions which had been used.

216 Proceedings of the British Association for [Sept,

.20. Mr. Snow Harris, on Thermometric Observations. He
produced a report of hourly observations, conducted at Ply-
mouth, and illustrated it by diagrams, representing the
mean daily curves of temperature at different periods of the
year. He compared them with similar observations made
at Leith.

21. Mr. G. Jerrard, on the Solution of Algebraic Equations.
An account of these researches was given by Professor
Hamilton.

22. Professor Phillips presented the third report on the
fall of rain, in continuation of his former reports. It fully
confirmed his remarkable results announced last year to
the Association, viz. that less rain falls, in proportion to
the height from the ground ; and extended them so as to
lead to some general theoretical views.

Mr. P. proposed that the Association should either pro-
vide, or recommend members to procure rain-guages, and
have them placed at different places, at different heights
from the ground, not to exceed 150 feet, which he appeared
to think quite sufficient for the collection of data, to enable
calculations to be made to ascertain the quantity of rain
which would fall into a guage at any height. This sug-
gestion led to some discussion in relation to the dew
which would be collected in the guage along with the rain,
and thus would vitiate the result. It was also stated that
radiation from different places had a great influence on
the formation of vapour. Thus, the Sugar-loaf and Howth
mountains are frequently capped with clouds when the
Dublin mountains are quite clear, hence the necessity of
care being taken in placing the guages. It was also stated
that there is a quantity of rain discharged from a variety
of those clouds known by the name of nimbus ^ which
never extends to within a considerable distance of the
ground. These clouds, which do not extend to the ground,
are well known. The rain falls into the lower air, and is
absorbed by it ; the latent heat for the solution being fur-
nished by the lower stratum of air, or by radiation or reflec-
tion from the ground itself. The guages, arranged as pro-
posed, would be no measure whatever of rain of this kind,
and would, consequently, furnish erroneous results for

1835.] the Advancement of Science. 217

calculation. The discussion was discontinued, in conse-
quence of the press of business.

Professor Rigaud made some observations.

23. Colonel Sykes read various details as to the mode of
conducting observations on temperatures, as practised by
himself in India, with a general statement of his results.
His method was to determine the boiling point of water,
at the altitude he wished to fix. In several examples the
error was only 1 6 feet in 4000. The apparatus recommended
was very simple, cheap, and portable.

24. Mr. M'Cullagh, on reflection and refraction of polarized
light at the surfaces of crystals. This communication con-
sisted of the results of a mathematical investigation of cer-
tain questions relative to the polarization of light, which
arise on comparing the theories of Fresnel and Cauchy, and
was full of most important views.

25. Mr. M'Gauley, on Magnetism. This paper was a con-
tinuation of his former communication, in which the author
entered at large into his theory of electro-magnetism, con-
tending that it is merely a state of electric excitation, reject-
ing the theory of currents, and concluding with observations
in favour of free inquiry on philosophical subjects.

Friday, 14M August. — 26. Professor Apjohn, on the Dew
Point. The author propounded a formula of connexion
between the dew point and the indication of the wet bulb
thermometer. His results tended to shew the conformity
of observations and theory.

27. Professor Hamilton read an abstract of Mr. Challis's
results respecting the simultaneous vibrations of a cylindri-
cal tube, and the column of air contained in it.

In the theory of cylindrical tubes, it is necessary to take
into account the vibration of the tube itself, as well as the
air contained. Certain laws have been deduced. It is pro-
bable that the vibrations of the pipes severally affect the
vibrations of the columns of air, and, consequently, the
sound produced.

28. Professor Wheatstone, on Speaking Machines. The
author noticed the attempts made by the Germans to form
pipes which would imitate the vowel sounds, De Kemplin
imitated different sounds with a conical tube, more or less
covered at the mouth. The author observed that the differ-

218 Proceedings of tke British Association for [Sept.

ence of the vowel sounds depended solely on the relative
size of the cavity of the mouth, altered by the tongue and
the opening of the lips. Willis, by a tube, (containing a
reed), altered in capacity by sliding, extended the scale to
other vowel sounds. He proposed a new mode of classifying
the consonant sounds. He exhibited a copy of the machine
of De Kemplin, in which the mouth is imitated by an India
rubber bell, and consonant sounds produced.''^

29. Mr. Whewell on a new Anemometer, The object kept
in view in the construction of this instrument, is to measure
the variation of intensity corresponding to the time. The
instrument was exhibited. It consists of a small vane, with
sails like a windmill, turning to the wind, and round its
axis. Its circular motion is thus converted into a much
slower vertical motion. A pencil is moved which traces a
line on a paper cylinder, shewing the direction and strength
of the wind. Sir John Ross made some remarks on his
own method of judging of the intensity of wind at sea, and
of the means adopted by him, during his last voyage, to regis-
ter the direction of the winds, and their velocity, combined
with the state of the weather, barometer, and thermome-
ter, from observations as accurately made as circumstances
would admit of, every half hour. He expressed his doubts
of the utility of the instrument in the Arctic regions ; but
said that it would have been desirable to have had such an
instrument with him in his last voyage, in order to test its
utility and accuracy.

30. Professor Lloyd detailed his magnetic observations in
Ireland, made in connexion with Captain Sabine, which
were undertaken at the request of the Association. They
consisted of observations of the dip and force. The lines
of equal dip were pointed out, with irregular variations of
intensity, probably depending on atmospheric causes not
yet understood. The lines of equal intensity were in some
measure determined. These have been found not generally
parallel with lines of equal dip, but, in Ireland, they are
not greatly different from parallel. At the south-east point
of the county of Waterford, the least dip was observed ; the
greatest was on the north-west point of Mayo, or Donegal .

* A short account of the same lecture has been given in Records of General
Science, vol. i. p. 469.

1835.] the Advancement of Science] " 219

In Limerick the dip was 71°; in Dublin, it was less. It
increased towards the north-west, in the direction of the
west magnetic pole, 71J°. In Armagh it was about 7ri5J°.
The author remarked the utility of having magnetic ob-
servations made at different stations. An interchange of
needles was made between Captain James Ross and Captain
Sabine, by which their respective observations would be
made to correspond.

31. Mr. Hamilton, 071 the Theory of Varying Orbits, He
explained the general nature of orbits, under the influence
of perturbations, expressed by Lagrange as a varying ellipse.
The author's method is a modification of this, by different
ellipses, founded on a former general method, in a some-
what simplified form.

Mr. M'Cullagh mentioned some investigations of his
own, upon the same subject ; and stated, verbally, a rule
which he had deduced.

Professor Powell stated certain difficulties of calculation
which had occurred in his optical researches, with a view
to elicit any assistance which the members of the Association
might be able to give in the solution of them.

32. Mr. Kane, on the Interference of Sound. He referred
to Herschel's suggestion of the distinction of sound by inter-
ference, as analogous to the absorption of light. In trying
the experiment he found anomalies in certain cases.

Mr. Addams remarked that the anomalies might easily be
explained, by considering the actual conditions of the case.

Mr. Wheatstone made some remarks, and described ex-
periments which seemed to reconcile the anomalies alleged.

Mechanical Science applied to the Arts. — The First Meeting
was held on Thursday, \^th August. Mr. Rennie, Presi-
dent; Dr. Lardner, Vice-President.

1. Mr. Hodgkinson of Manchester detailed some experi-
ments in reference to the collision of beams and piles. This
communication formed the continuation of a former paper
read to the Association. The results were 1 : That when
cast iron beams were brought forcibly in contact with balls
of different kinds of metals of equal weights, the deflection
was the same in distance, whatever the nature of the metals

220 Proceedings of the Biitish Association for [Sept.

was. 2. That the impinging masses rebounded after the
stroke, through the same distance under similar circum-
stances. 3. These effects are not in any way dependent on
elasticity, but are the same as theory would point out to be
the consequence of the collision of bodies destitute of elasti-
city. He mentioned also that wire resisted fracture most
effectually, when it was extended by means of a weight,
equivalent to ^ of the weight required to break it.

2. Mr. Mallet read a paper on the fracture of bars of
cast iron.

3. Mr. Ettrick read an account of a compass which, by
a peculiar contrivance, adjusted the cardinal points so as to
correspond with the true points in the horizon : thus, ob-
viating the necessity of allowing for the variation. This
effect was produced by securing the needle upon the card
by moveable clamps, and adjusting it for the magnetic va-
riation of Greenwich, with a contrivance for altering it in
situations where the local variation was different.

4. Mr. Pritchard shewed an achromatic microscope, in
which the angular aperture of the object glasses exceeds
any that have, hitherto been constructed. It is peculiarly
serviceable in examining flax, cotton, silk, &c.

5. Mr. Russell read a paper on the solids of least resist-
ance, in reference to steam vessels, and related experiments
which tended to prove that the form of prow best suited to
rapid progress through water, was a parabolic one. This
was disputed by Professor Mosely and Dr. Lardner.

6. Mr. John Taylor stated that by calculating from the
duty on steam engines in Cornwall, it appeared, that work
performed by means of 1 bushel of coal, required 10 or 12
years ago 2 bushels ; and, in the time of Bolton and Watt's
patent 4 bushels were necessary, while at the commence-
ment of the use of steam power, the coal required was 16
bushels. The steam engines at present in Cornwall were
equal to 44,000 horse power.

7. Dr. Lardner made some observations on Rail Roads.
He stated that every road offers a sensible resistance to
traction, but this on a rail-road is less, because the surface
is more uniform. The resistance on a rail-road to the
power of traction is always the same, as the resistance pro-
duced by ascending an acclivity, rising 1 foot in 250 ; that

1835.] the Advancement of Science. 221

is, supposing the rail-road to be level. Suppose a rail- road
rising 1 foot in 250, resistance to traction then proceeds
from two causes, the resistance on the level, as already ex-
plained, and the resistance offered from the actual declivity.
The resistance to be overcome on the level is equivalent to
nine pounds per ton, and on the road ascending 1 foot in
250, it vv^ould be eighteen pounds per ton, and thus it is
seen, that in the latter case, the drawing power must exert
twice the force necessary on the level. If the road rose 2
feet in 250, the drawing force would be twenty-seven pounds
to the ton. This view of the subject is confined to ascents,
but it should not be forgotten, that when a rail-road is
worked, the transit is from one end to the other. It is
necessary, in estimating the merits of rail-roads to consider
their action downwards as well as upwards. In coming
down a steep, no force is required to impel an engine, and
the gravity restores that force in going down which it has
robbed from it in the ascent. You have to provide, in an
ascent of 1 foot in 250, for a resistance of eighteen pounds
to a ton, but in descending no force is required. Kit was
desired to strike an average between the ascent and descent,
the road would present a surface which would be equivalent
to a level. This point, respecting ascent and descent, struck
the House of Lords, before which he gave this opinion, as a
paradox, but it was one only in sound and not in reality.
Dr. Lardner remarked, that these observations referred to
ascents not more steep than 1 foot in 250 ; but supposing
the rise to be 3 feet in 250, and where the strain would be.
consequently, thirty-six pounds in each ton, would gravity
give this back in the descent ? It was true, that no power
was required in descending, but while only nine pounds
were gained in the descent, twenty-seven pounds were lost
in the ascent. Beside the loss of power, there was also the
danger resulting from the too great velocity occasioned by
sudden descents. In one of the lines of rail- way, for which
a bill had been applied to the House of Lords, there was a
slope of 1 foot in 106 in a descent of two miles and a-half
long, and the velocity given to an engine on arriving at the
foot of the slope, could not amount to less than 70 miles art
hour. To mitigate defects arising from these abrupt de-
scents, breaks were applied, but not always with success.

222 Proceedings of the British Association for [Sept.

The break is a piece of wood, pressed against the tire of the
wheel by a lever, and if it acts with full effect it ought to
prevent acceleration. He had seen several cases in which
it had totally failed, and one instance, which occurred he
would detail. At one of the slopes between Manchester
and Liverpool, he was descending with a loaded train of
150 tons. The operative engineer, whether through a de-
sire of displaying the engine's movements, or through
neglect, forget to apply the break at the commencement
of the slope ; when half-way down, the velocity became so
great, that he requested the breaks to be applied, but on
doing so, they were instantly burned. The train went down
at a tremendous speed, although the supply of steam had
been cut off. When the train had been stopped it was found
that the wheels of one of the waggons which revolved with
the axis had been broken, and yet notwithstanding this
accidental drag, the speed amounted to at least fifty miles.
It was objectionable to have any slope exceeding 1 in 250,
for when the excessive natural powers of gravitation were
resorted to, control over its movements was impossible.
The conclusion to be arrived at, although it appears para-
doxical is that you may construct two rail-roads, say of 100
miles in length, one level, the other going over mountains,
and yet the two rail- roads may be worked by the same me-
chanical power. Suppose in the one you ascend 1 in 250,
and descend in the same ratio, a pull of eighteen pounds to
the ton is required only fifty miles, and on the other half
you descend by inertion. On the level road a pull of nine
pounds to the ton is required, from the entire distance of
miles, and thus the extent of exertion is equalized. It was
not, however, to be forgotten, that they should have a re-
gard to the power used. If the power to be used was that
of animals, then it might happen that the hilly road would
be better than the level, for nothing was better understood
than that a dead and unvarying pull upon the same set of
muscles, would have the effect of causing the labour to be
more severe, while a varying pull would alternately give
quiescence and exercise to the muscles. If the line was so
disposed as to throw the whole ascent in one pots, the ad-
vantage would be gained of having the rest of the road
nearly level. But the cost of attaining this advantage

1835.] the Advancement of Science. 223

should not be forgotten. Steeps of this description required
an increased power, and the engines capable of working on
the general line of road, would not be capable of exerting
an increased force. There were only two ways of ascending
sudden ascents, one by the agency of an additional engine,
find the other, by having the whole train pulled up by means
of a rope. The additional engine, would occasion much
additional expense, for the supply of them would always be
preserved, and the men should be paid their wages whether
wanting or not. The use of the rope would occasion an
enormous waste of power, and he mentioned the instance
of a place, where an ascent of 1 foot in 106 occurred.
The rope was five miles long, and its weight was 60,000
pounds. Dr. Lardner next referred to one point on
which he seemed to consider that engines generally were
at variance with what was correct. He contended that the
heat of the fire is directly proportional to the quantity of
the steam allowed to escape in a definite time into the flue,
and consequently that half the number of blasts of steam
projected into the chimney in an engine going up a hill,
would have the same effect in exciting the fire as double the
number of blasts of half the condensation, when the engine
was running on a level plane.

Friday^ Sth August, — Mr. Ettrick read an account of cer-
tain improvements on steam engines, and on securing the
seams of boilers, of a machine for drilling boiler plates, and
of an astronomical clock.

9. Mr. Cheverton read a communication on the sculp-
ture of busts by machinery, exhibiting beautiful specimens.

10. Mr. Grubb made some very able and practical obser-
vations on an improved model for mounting an equatorial
instrument, adopted by Edward J. Cooper, M. P., of Mack-
roe Castle, county Sligo.

Mr. Cooper bore testimony to the excellence of the in-
strument, as also to the talent and perseverance of Mr.
Grubb in his scientific improvements and inventions.

11. Lieutenant Denham stated some details in reference,
to the vibratory effects of rail-roads, especially over tunnels.
A discussion then took place between Dr. Lardner and Mr.
Vignolles, on the disadvantages arising from acclivities on
rail -roads, which appeared to the Section as over-rated by
Dr. Lardner.

224 Proceedings of the BHtish Association for [Sept.

12 Mr. Stevelly described a self-registering barometer;
The principle of this instrument is to suspend the mercurial
cistern by a mercurial hydrometer, so that it may move
downwards by arithmetical distances, for equal additions
to its weight, and vice versa. Hence, if a scale be fixed be-
side it, an index carried by the cistern as it falls and rises,
will mark the corresponding positions.*

General Meetings. — The first general meeting was held in the
Rotunda, on Monday, at 8i p.m., at which it is calculated above
2,000 persons were present.

Sir Thomas Brisbane, in resigning the Chair of President of the
Association, referred to the benefits which had already proceeded
from the institution of the Association. He begged to propose, as his
successor. Provost Lloyd, who took the Chair and addressed the meet-
ing at considerable length, in reference to the importance of Science,
and the certainty that the word and works of the Creator would
be found, when duly understood, to correspond with each other.

Professor Hamilton then read the annual address. We regret
that want of space prevents us from inserting the whole of his elo-
quent speech in reference to the published reports of the Association.
He observed, " they belong to our own age ; they are the property
of ourselves as well as of our children. To stimulate the living, not
less than to leave a record to the unborn, was hoped for, and will be
attained, through those novel and important productions. In holding
up to us a view of the existing state of science, and of all that has
been done already, they show us that much is still to be done, and
they rouse our zeal to do it. Can any person look unmoved on the
tablet which they present of the brilliant discoveries of this century,
in any one of the regions of science ? Can he see how much has
been already built up, and is still in process of building, without
feeling himself excited to give his own aid also to the work, and to
be enrolled among the architects, or at least, among the workmen ?
Or can any one have his attention guided to the many wants that re-
main, can he look upon the gaps that are still unfilled, even in the most
rich and costly of those edifices, like the unfinished window that we
read of in the palace of eastern story, without longing to see those
wants supplied, that palace raised to a still more complete perfection,
without burning to draw forth all his own old treasures of thought,
and to elaborate them all into one new and precious offering."

He then took a brief view of the reports in the last volume of
Association Reports, beginning with the paper of Professor Rogers
on the Geology of America.

The object proposed by Professor Rogers was to convey a clear
summary of what had been ascertained concerning the geology of
America, whether the knowledge acquired had been communicated
to the public or not. This is not very difierent from the object con-
templated by other reporters ; but in the execution of the report it

* The reports of the remaining sections will be given in the'su'cceeding number.

1835.] the Advancement of Science. 225

is found that a marked peculiarity arises. For the far greater por-
tion of the report contains the result of Mr Rogers' own reasonings
on data, many of which appear for the first time in his essay. It has
therefore, more the character of a memoir than of an ordinary re-
port. Were any one to adopt this plan in treating of the state of
European geology he might be blamed, because the value of such a
report would consist in the discussion of a vast mass of published
data, and in the comparison of theoretical notions proposed by per-
sons of high reputation. But in treating of America this was not the
case ; because, first, little authentic was known in Europe on the
subject — second, there are few American authors of high repute in
geology. This character of originality is certainly well supported by
the author's own researches, and it is not surprising if his work
contains some errors, still less remarkable that it should have excited
some opposition at home. But the writer of the report has really
taken much pains, has exhibited much patience, and has brought to
his task a competent knowledge of European geology. It has cer-
tainly cleared our notions of the general features of American geo-
logy, and particularly augmented our positive knowledge of the more
recent deposits, as regards organic remains, mineral characters, and
geographical features. It is to be continued.

Another report which is almost entitled to be called a report on
foreign science, is that of the Rev. Mr. Challis on the theory of
capillary attraction, which is a sequel to that presented at Cambridge
on the common theory of fluids, and which the author proposes to
follow up hereafter by another report on the propagation of motion
as affected by the development of heat. Mr. Challis remarks, that
while many questions in physics are to be resolved by unfolding through
deductive reasoning the consequences of facts actually observed, there
is also another class of questions in physical science, in which the
facts that are to be reasoned from are not phenomena ; for example
the fact of universal gravitation for which the evidence is inductive
indeed, but yet essentially mathematical, the fact not coming itself
under the cognizance of any of our senses, although its mathematical
consequences are abundantly attested by observations. Mr. Challis
goes on to say — " The great problem of universal gravitation which
is the only one of this class that can be looked upon as satisfactorily
solved, relates to the large masses of the universe, to the dependence of
their forms on their own gravitation and the motions resulting from
their actions on one another. The progress of science seems to tend
towards the solution of another of a more comprehensive nature,
regarding the elementary constitution of bodies and the forces by
which their constituent elements are arranged and held together —
Various departments of science appear to be connected together by
the relation they have to this problem. The theories of light, heat,
electricity, chemistry, mineralogy, crystallography, all bear upon
it. A review therefore of the solutions that have been proposed of
all such questions as cannot be handled without some hypothesis
respecting the physical condition of the constituent elements of bodies,
would probably conduce by a comparison of the hypotheses, towards
reaching that generalization to which the known connexion of the
sciences seems to point." The author finally remarks, that " Ques-

VOL. II. Q

226 Proceedings of the British Association for [Sept.

tions of this kind have of late largely engaged the attention of some
French mathematicians, and the nature of their theories, and the
results of the calculations founded on them, deserve to be brought as
much as possible into notice." Acting upon these just views, Mr.
Challis has accordingly performed for the British Association and for
the British public, the important office of reviewing and reporting
upon those researches of Laplace, Poisson, and Gauss, respecting the
connexion of molecular attraction, and of the repulsion of heat with
the ascent of fluids in tubes, which give to his report so much of that
foreign character which I have already ventured to ascribe to it ; yet,
it is just to add, and, indeed, Mr. Challis does so, that as Newton
first resolved the mathematical problem of gravitation, in its bearings
on the motion of a planet about the sun, and went far to resolve the
same extensive problem in its details of perturbation also, he likewise
first resolved a problem of molecular forces, and clearly foresaw and
foretold the extensive and almost universal application of such forces
to the mathematical explanation of the more varied classes of phe-
nomena, and that the theory of capillary attraction, in particular, has
received some very valuable illustrations in England from the late
Dr. Thomas Young. I ought to mention that a very interesting re-
port on the foreign mathematical theories of electricity and magnetism,
was read in part this morning to the mathematical and physical sec-
tion, by the Rev. Mr. Whewell. The next report after that of Mr.
Challis in the volume, is the report I already alluded to, by Professor
Lloyd, on the progress and present state of physical optics, respect-
ing which I should have much to say, if I did not fear to offend the
modesty of the author, and were not restrained by the recollection
that he is a member of the same University with myself, and a
countryman and friend of my own. I shall, therefore, simply ex-
press my belief, that no person who shall hereafter set about to form
an opinion of his own on the question between the two theories of
light, will think himself at liberty to dispense with the study of this
report. I may add that it also, as well as that of IVIr. Challis, draws
largely from foreign stores ; but if Huygens was the first inventor,
and Fresnel the finest unfolder, and Cauchy the profoundest mathe-
matical dynamician, of the theory of the propagation of light by waves,
and if the names of Malus, Biot, and Arago, and other eminent
foreigners are familiar words in the annals of physical optics, we also
can refer among our own illustrious dead to names enshrined in
the history of this science, to the names of Newton and Wollaston
and Young, and among our living fellow-countrymen and fellow-
members of this Association, (unhappily not present here), we have
Brewster and Airey to glory of. It should be mentioned that the
author of the report has himself made contributions to the science of
light, more valuable than any one could collect from the statements
in the report itself, and that important communications in that science
are expected to be made during the present week, by Professor Powell
to a general meeting, and by Mr. MacCuUagh to the physical section^
The remaining reports in the new volume are those by Mr.
Rennie on Hydraulics ; by Dr. Henry of Manchester on the laws
of contagion, and Professor Clark of Cambridge on animal physio-
logy, and especially on our knowledge respecting the blood. Mr*

1835.] the Advancement of Science. 227

Bennie's report contains, I believe, new facts from the manuscripts
of his father, and is in other ways a valuable statement, industriously-
drawn up, of the recent improvements in the practice of hydraulics,
to the theory of which science it is to be lamented that so little has
lately been added: and without pretending to judge myself of the
merits of the two other reports, I may mention them as compositions
which I know to have interested persons, with whose professional
and habitual pursuits they have no close connexion, and therefore, as
an instance of the accomplishment of one great end proposed by our
association, that of drawing together different minds, and exciting
intellectual sympathy. The other contents of the volume are accounts
of researches undertaken at the request of the association. Notices
in answer to queries and recommendations of the same body, and
miscellaneous communications. Of these, it is of course impossible
to speak now ; your time would not permit it. Yet, perhaps, I ought
not to pass over the mention of one particular recommendation which
has happened to become the subject of remarks elsewhere — I mean
that recommendation which advised an application to the lords
of the treasury for a grant of money, to be used in the reduction
of certain Greenwich observations, the result of which recommen-
dation is noticed in the volume before us.

' In all that I have hitherto said respecting this Association, I have
spoken almost solely of its internal effects, or those which it produces
on the minds and acts of its own members. But it is manifest that
such a society cannot fail to have also effects which are external, and
that its influence must extend even beyond its own wide circle of mem-
bers. It not only helps to diffuse through the community at large a
respect and interest for the pursuits of scientific men, but ventures even
to approach the throne, and to lay before the King the expression of the
wishes of this his parliament of science, on every subject of national
importance which belongs to science only, and is unconnected with the
predominance in the state of any one political party. It was judged
that the reduction of the astronomical observations on the sun and
moon, and planets, which had been accumulating under the care of
Bradley and his successors, at the Royal and National Observatory of
Greenwich, since the middle of the last century, which, except so far as
foreign astronomers might use them, had lain idle and useless till
now, to the great obstruction of the advance of practical as well as
theoretical science, was a subject of that national importance, and
worthy of such an approach to the highest functionaries of the state.
It happened that I was not present when the propriety of making
this application was discussed, so that I do not know whether the
authority of Bessel was quoted — That authority has not at least been
mentioned to my knowledge, in any printed remarks upon the question,
but as it bears directly and powerful thereon, you will permit me,
perhaps, to occupy a few moments by citing it. Professor Bessel of
Koenigsberg, who, for consummate union of theory and practice,
must be placed in the very foremost rank, may be placed perhaps at
the head of astronomers now living and now working, published not
longago that classical and useful volume, the Tabula Re^iomontanap,
which I now hold in my hand. In the introduction to this volume
of tables, Bessel remarks, that '^ the present knowledge of the solar

q2

228 Proceedings of the British Association for [Sept.

system has not made all the progress which might have been expected
from the great number and goodness of the observations made on the
sun, and moon, and planets, from the time of Bradley down. It may
indeed be said with truth that astronomical tables do not err now by
so much as whole minutes from the heavens ; but if those tables
differ by more than live seconds now, by using- all the present means
of accurate reduction, from a well observed opposition of a planet — for
example, their error is as manifest and certain now as an error ex-
ceeding a minute was, in a former state of astronomy — and the
discrepancies between the present tables and observations are not
uncommonly outside that limit, the case is doubtful. Errors of
observation to such amount they cannot be ; and, therefore, they can
only arise from some wrong method of reduction, or wrong assumed
elliptic elements or masses of the planets, or insufficiently developed
formulae of perturbation, or else they point to some disturbing cause
which still remains obscure, and has not yet been reached by the light
of theory. But it ought surely to be deemed the highest problem of
astronomy, to examine with the utmost diligence into that which has
been often said but not as yet in every case sufficiently established,
whether theory and experience do really always agree. When the
solution of his weighty problem shall have been most studiously made
trial of, in all its parts, then either will the theory of Newton be
perfectly and absolutely confirmed, or else it will be known beyond all
doubt that in certain cases it does not suffice without some little
change, or that besides the known disturbing bodies there exist some
causes of disturbance still obscure. And then after some technical
remarks, less connected with our present subject, Bessel goes on to
say, '* to me considering all these things together, it appears to be of
the highest moment (plurimum valere) towards our future progress
in the knowledge of the solar system, to reduce into catalogues as
diligently as can be done according to one common system of elements,
the places of all the planets observed since 1750, than which labour,
I believe, that no other now will be of greater use to astronomy."
(Quo labors nullum credo nunc majorem utilitatem Astronomice
allaturum esse); such is the opinion of Bessel ; but such is not the
opinion of an anonymous censor, who has written of us in a certain
popular review. To him it seems a matter of little moment that old
observations should be reduced. Nothing good he imagines can
come from the study of those obsolete records. It may be very well
that thousands of pounds should continue to be spent by the nation
year after year in keeping up the observatory of Greenwich, but as
to the spending J, 500 in turning to some scientific profit the accu-
mulated treasures there, that is a waste of public money, and an
instance of misdirected influence on the part of the British Associa-
tion. For you, gentlemen, will rejoice to hear, if any of you have
not already heard it, and those who have heard it already will not
grudge to hear it again, that through the influence of this associa-
tion what Bessel wished, rather than hoped, is now in process of
accomplishment ; and, that, under the care of the man who in
England has done most to show how much may be done with an
observatory, that national disgrace is to be removed of ignorance or
indifference about those scientific treasures which England has

1835.] the Advancement of Science. 229

almost unconsciously been long amassing, and which concern her as
the country of Newton and the maritime nation of the world ; for the
spirit of exactness is diffusive, and so is the spirit of negligence.
The closeness indeed of the existing agreement between the tables
and the observations of astronomers is so great that it cannot easily
be conceived by persons unfamiliar with that scienee. No theory has
ever had so brilliant afortune or ever so outrun experience as the theory
of gravitation has done. But if astronomers ever grow weary, and
faintly turn back from the task which science and nature command,
of constantly continuing to test even this great theory by observation,
if they put any limit to the search, which nature has not put or are
content to leave any difference unaccounted for, between the testimony
of sense and the results of mathematical deduction, then will they
not only become gradually negligent in the discharge of their other
and more practical duties, and their observations themselves and their
nautical almanacks will then degenerate instead of improving, to the
peril of navies and of honour ; but also they will have done what in
them lay, to mutilate outward nature, and to rob the mind of its
heritage. For, be we well assured that no such search as this, were
it only after the smallest of those treasures which wave after wave
may dash up on the shore of the ocean of truth, is ever unrewarded.
And small as those five seconds may appear, which stir the mind of
Bessel, and are to him a phophecy of some knowledge undiscovered,
l^erhaps unimagined by man, we may remember that when Kepler
was " feeling ," as he said," the walls of ignorance ere yet he reached
the brilliant gate of truth," he thus expressed himself respecting
discrepancies which were not larger for the science of his time : —
*' These eight minutes of difference which cannot be attributed to the
errors of so exact an observer as Tycho, are about to give us the means
of reforming the whole of astronomy." We indeed cannot dream
that gravitation shall ere become obsolete ; perhaps it is about to
receive some new and striking confirmation ; but Newton never held
that the law of the inverse square was the only law of the action of
body upon body, and the question is, whether some other law or mode
of action, co-existing with this great and principal one, may not mani-
fest some sensible effect in the heavens to the delicacy of modern
observation, and especially on modern reduction. It was worthy of
the British Association to interest themselves in such a subject: it
was worthy of British rulers to accede promptly to such a request.
I have been drawn into too much length by the consideration of this
instance of the external effects of our association, to be able to do
more than allude to the kindred instance of the publication of the
observations on the tides in the port of Brest, which has, I am informed,
been ordered by the French government, at the request of M. Arago,
and the French board of longitudes, who where stimulated to make
that request by a recommendation of the British Association at Edin-
burgh. Many other topics, also connected with your progress and
prospects, I must pass over, having occupied your time so long ; and
in particular I must waive what, indeed, is properly a subject for your
general committee — the consideration whether anything can be done
or left undone, to increase still more the usefulness of this association,
and the respect and good will with which it is already regarded by

230 Proceedings of the British Association for [Sept.

the other institutions of this and of other countries. As an Irishman,
and a native of Dublin, I may be suffered in conclusion to add my
own to the many voices which welcome this goodly company of Eng-
lish, and Scottish, and foreign visitors to Ireland and to Dublin.
We cannot, indeed, avoid regretting that many eminent persons
whose presence we should much enjoy, arc not in this assembly,
though not, we trust, in any case from want of their good will or
good opinion. Especially we must regret the absence of Sir David
Brewster, who took so active a part in forming this association : but
I am authorised, by a letter from himself, to mention that his ab-
sence proceeds entirely from private causes, and that they form the
only reason why he is not here. Herschel, too, is absent ; he has
borne with him to another hemisphere his father's fame and his
own; perhaps, from numbering the nebulae invisible to northern
eyes, he turns even now away to gaze upon some star which we, too,
can behold, and to be in spirit among us. And other names we miss ;
but great names, too, are here ; enough to give assurance that in
brilliance and useful effect this Dublin Meeting of the Association
will not be inferior to former assemblings, but will realise our hopes
and wishes, and not only to give a new impulse to science, but also
cement the kindly feeling which binds us all together already.

Tuesday, Wth August,— Dr. Lardner, on Steam Carriages.
He commenced, by saying, that at the desire of the British Association,
he would address the meeting upon the application of steam gene-
rally, but more especially as applied to transport over land. After
explaining the properties of steam, and the manner in which water
becomes converted into steam, he illustrated the power of this agent
by the height with which a plug was raised, when water heated
under it became converted into vapour. Thus, every solid inch of
water, when converted into steam, is capable of supporting above a
ton weight. The speed at which carriages were propelled, depended
upon the speed with which steam was applied to the machinery, and
subsequently generated in the boiler. Heat operated with greater
power than some of his hearers conceived, and, as an evidence, he
would mention, that in travelling from Liverpool to Manchester, he
found that new grate-bars put into the furnace at Liverpool, were
fused and destroyed by the action of the fire. In addition to the
present mode of generating steam, there were several other very
ingenious plans suggested. By one plan, water was contained in
parallel plates, and fire passing up between the water, to use a
familiar phrase, became roasted into steam. By another the boiler
was formed of consecutive cylinders, placed one within the other,
until they terminated in the centre. Another plan had been adopted
by Mr. Gurney : great bars formed part of the boiler, and water was
contained in them all. Other bars formed the back and also the roof.
With reference to the use of engines on railroads, it was well known
that no inert body was capable of varying its energies without loss.
It was upon this principle, among others, that railways had been
found more adapted for transit than stone roads. The latter were
variable ; and, from their inequalities, caused a perpetually changing
resistance. Iron railroads were superior, from their uniformity.

1835.] the Advancement of Science. 231

smoothness, and hardness, and from the diminished resistance pre-
sented. It was a common error to suppose that the road on which
one was most easily drawn, was that on which a vehicle could pass
with facility, but, in reality, a carriage on a paved street required
less propelling power than on a macadamized road. It was also sup-
posed that the resistance of a road to a carriage merely depended upon
the nature of the surface, but this was not the truth, for much de-
pended upon the foundation, and if it was bad, the weight of the
wheels forced up the surface into little hills, over which there was
great difficulty in ascending. To constitute a good road, smoothness,
hardness, and evenness were necessary j and if any road could be
constructed perfectly in accordance with this description, no power
of draught would be necessary. Iron rail-roads approached most
nearly to perfection ; but though they possessed hardness they were
not entirely smooth ; and in the Liverpool rail-road, which had been
now used for some period of time, a passenger could tell, from the
inequality, when he was passing from one joint to another. The
force required for propulsion along a level rail-road, was about 9 lbs.
to one ton ; but supposing the rail-road to rise 1 foot in 250, although
the elevation could not, be discovered by the eye, yet a double force
of draught would be required. When the rise was more than 1 in
100, it exceeded the power of the machine, and then it was necessary
to use additional means of transit. The rise from Carlisle Bridge
to the Rotunda was about 1 foot in 500, and from Nassau Street
to Ann Street it was one in 90, and at this elevation no carriage
could go. There ought to be no sudden turns in rail-roads; no
curves perceptible in their bend. A sudden curve on an ordinary
road would be but a trifling objection, but when carriages were
travelling at the rate of forty miles, such an abrupt bend should
be avoided. In the Kingstown railway, there was only one
blemish : the suddenness of the curve near Kingstown ; and if the
rail- way was to be carried further on, as he hoped it would, the effect
would be felt greater, from the additional velocity not now required
at the termination of the line where the defect existed. He under-
stood that casual circumstances obliged the engineer to make the
draught curve of not less than half a mile, while it should have been
at least one mile. It was objected to railways that they were not
as good as common roads, because they did not admit of being made
where there were hills, but this was a silly argument, for illustrating
the subject by reference to a familiar instrument, he would say that
the edge of the razor would be blunted by what might not affect a
carving knife, because the razor approached nearest to perfection.
Dr. Lardner then referred to the mode of cutting tunnels to avoid
ascents ; and stated that on the railway between Birmingham and
London there will be seven tunnels, one of which will be a mile and
a half long, a second a mile long, and a third, at Primrose Hill, half
a mile long. Supposing that the power of steam had obtained its
maximum, when the rail-road from Liverpool to London would be
completed, the journey between the two places would be performed
in less than ten hours. It was not generally known that the weight
of the train considerably retarded the motion. He had travelled 48
miles an hour on the Kingstown rail-road, and upwards of 50 on the

232 Proceedings of the British Association for [Sept.

Liverpool ; and this speed could be accelerated to 60 miles an hour*
At this rate we might reach Liverpool from London in three hours
and a half.

A bill has been obtained to connect London and Southampton, and
another is about to be obtained for a Bristol rail way.

It is pleasant to contemplate the effects of facility in communica-
tion. Formerly, 450 persons passed daily between Liverpool and
Manchester. Now, 1309 persons pass. Between London and
Liverpool 1350 persons pass. When the rail-road is completed the
number will be above 4000.

It is proposed to have a line of road through Ireland, between
Dublin and Valentia, to constitute the high way to America. The
formation of this road, which will conduct all passengers between
Britain and America, through the middle of Ireland, will tend, in
the opinion of Dr. Lardner, to produce tranquillity and peace over
the length and breadth of the island.

In America there are 40 rail-roads completed, and about 100 in
progress. The longest is 50 miles at present. But the Ohio rail-
way, now forming, is above 300 miles in length. '

Wednesday y \2th August. ^

After the reports of the sections had been read by the several
secretaries. Professor Powell proceeded to give a lecture on the
theory of the dispersion of light.

In introducing the subject, he observed, that to many, this subject
might appear dry and cold, but it had a peculiar interest to those who
studied it, for it was prosecuting truth for its own sake. It had,
therefore, a high, sublime and sacred claim to attention. Its pheno-
mena were required to be investigated by refined analysis. The
study was minute, it is true, and to many, therefore, it might appear
trifling. But to such persons, the saying of tlie Honourable Robert
Boyle might be given as an answer. He was an Irishman, and was
the first to reduce into practice the theories of Bacon. When cen-
sured by his friends for engaging in occupations apparently frivolous
and trifling, he replied, ^' There is nothing unworthy of being inves-
tigated which was thought worthy of being created by God,"

The lecturer proceeded to state that Professor Airy had suggested
to him to compare the relation deduced from Cauchy's theory between
the length of a wire and the refractive index for each of the different
standard rays, with the numerical values of those quantities obtained
by experiment for different media. This he accordingly attempted
to do for all the ten media examined by Fraunhofer. The results
will be seen in the Phil. Trans, for the present year : And, it is
conceived the coincidences are such as to justify the conclusion, that
M. Cauchy's theory is established by observation as far as those media
are concerned. The author has since commenced a more extended
series of measurements of the deviations of the definite standard rays
for prisms of various transparent media, by means of a telescope
attached to a graduated circle having two opposite visions. Such a
series of observations is one of the recommendations of the British
Association ; and the author, therefore, hoped that some of its mem-
bers may be willing to co-operate with him should they have oppor-
tunities of procuring for examination some of the less common refrac-

1835.] the Advancement of Science. 233

ting substances in the form of prisms, in such a state of purity and
transparency as to see the lines.

He also mentioned that he had already obtained approximate results
from oil of cassia, which agreed very nearly with theory.

Mr. Whewell made some observations upon the phenomena of the
tides, and referred with great satisfaction to the observations at pre-
sent in progress of determination, along the shores of Great Britain,
upon the tides, and noticed the co-operation of the Dutch government
on this important subject.

Thursdajf, I3th August. — No Lecture.

Friday, 14th August. — The chairmen of the several Sections
gave an account of the various papers read during Thursday's and
Friday's Meetings.

Professor Babbage then proceeded to offer some suggestions as to
the age of peat mosses, &c. He stated that the idea which he
hoped to see followed out, occurred to him as he was sitting under a
beautiful ash tree in the park of a friend with whom he was living.
The age of trees is known by the number of rings in the section of
them, and he remarked that many of those rings were of a large size,
while others were small. In conclusion, he (Professor Babbage) drew
from these variations, that where the rings were large the year was
favourable to vegetation ; while, if they were small, a less supply had
been afforded to the tree. The Professor, from these appearances,
w^as induced to believe, that means were provided, by the inspection
of these rings in flifferent trees, to ascertain different periods of time,
and the fertility or barrenness of the several years.

Professor Sedgwick gave account of the labours of the Geological
Section.

Saturday, IbthAugust. — A General Meeting was held at 2 o'clock,
when the Rev. Mr. Vernon Harcourt, as general secretary, addressed
the meeting. He apologized for the delay which had occurred, but
hoped it would be excused on account of the importance of the sub-
jects which had been discussed before the committee. Invitations
had been sent from Bristol, Liverpool, Birmingham, Manchester and
Newcastle, soliciting the Association to have its next meeting in those
several places, and what decided the selection in favour of Bristol,
was from that city having sent the first decided invitation. Every
kind of accommodation had been offered by the public and corporate
bodies. A difficulty then arose in selecting the officers of the Asso-
ciation in provincial towns, as they might not wish to undergo the
arduous labours and duties necessary to give effect to the proceedings,
but there did not appear to be a probability of any inconvenience
arising in the present instance. Mr. Harcourt then read the several
sums of money recommended by the Sections to be advanced for the
prosecution of scientific objects in various branches. — It had also been
determined to apply to Government to send out an expedition to the
Antartic Regions, for the purpose of discovering the Southern Mag-
netic Poles. He felt much gratification in announcing that the re-
sources of the Association had increased to a greater degree at this
than at any former meeting. He would not waste time in advocat-
ing the propriety of the system adopted by the Association, for that
system was the most efficacious iu imparting knowledge. Mr. Har-

234 Proceedings of the British Association for [Sept.

court observed,that from the occurrences in the Sections, not only were
new subjects remarked, but the spirit in which these discoveries made
was also shewn. The members also derived incitement to new exer-
tions, from the kindness with which they had been treated in every
place, and surely in none more than the metropolis of Ireland. The
Association offered important means for facilitating discoveries in
science, and for awarding the just meed of approbation to the talents
of distinguished philosophers. It was said to Doctor Black, by a
friend, " How do you happen to have made important discoveries,
and then stop short instead of completing those inventions, as
Priestley and Watt have done. " They have not escaped me,"
was the reply, " but I am afraid of the reviewers." The reviewers
might formerly have had the power to depress merit, but they
could not do so any longer. If any man was too modest to give
an account of his scientific proceedings to the Section, another
member would be prepared to act as a deputy, in order to get
that praise awarded to him which he might happen to deserve.
There were numerous other points in which the merits of the
Association could be considered, but time did not allow him to
dilate upon them. Mr. Harcourt read the names of the individuals
appointed as officers for the year. Treasurer, Mr. John Taylor —
General Secretaries, Mr. V. Harcourt and Mr. Baillie — Assistant
General Secretary, Professor Phillips — Secretaries, Dr. Turner and
Mr. Yates. Mr. Taylor, the treasurer, gave a statement of the
funds of the society. On the 30th of July last there was cash in
the treasurer's hands to the amount of <£ 509. — in the stocks £2361.
and unsold copies of works about £ 560. In Dublin the treasurer
had received 1228 subscribers, and £ 1750, together with an addi-
tional sura of £ 94, for books sold, making the total income £5214.
The expenses and sums due by the Association were probably £1000,
leaving a clear property of £4,214. It was gratifying to state that the
receipts of the preceding year in Edinburgh were £ 1,626, while in
Dublin they amounted to £ 1,750. It was also very pleasing to be
able to state that grants for the advancement of science, of £ 1,700
had been placed this year at the disposal of the comtnittee.

This sum was distributed as follows : £ 500 for a duplicate reduc-
tion of the astronomical observations made at L'Ecole Militaire of
Paris ; £ 100 for determining the constant of lunar notation ; £ 100
for observations on the temperature of the tide ; £250 for continuing
tidal observations at Liverpool and the port of London ; £ 100 for
tlie advancement of Meteorology ; £ 30 for the continuation of
Professor Wheatstone's experiments ; £ 30 for reducing to practice
Dr. Jerrard's plan for solving equations of the 5th or higher degrees;
£20 to Mr. Johnston for completing tables of chemical constants;
£ 30 to Mr. Fairburn for experiments on the hot and cold blasts for
iron works; £ 105 for prosecuting researches in British fossil Ich-
thyology ; £ 50 for researches into the absorbents ; £ 50 for exa-
mining the sounds of the heart.

Saturday Evenin<^, \5th August. — Dr, Barry gave an account
of his ascent to Mount Blanc. He mentioned that 20 persons only
have reached the summit of the mountain, and of these 12 were
Englishmen.

1835.] the Advancement of Science. 235

Professor Babbage made some remarks upon a whirlpool observed
at the Island of Cephalonia, through which the sea has poured for 40
years. He had applied to Lord Nugent, the Governor of Corfu, to
know whether he was acquainted with the fact, and that nobleman
gave him a statement upon the subject, which he would endeavour to
report, although perhaps, not with sufficient accuracy, as he had not
taken notes at the time. A hole is seen between two rocks, and an
excavated channel conveys the sea water into a pit, 100 yards
round, and four feet below the surface. The sea that enters rushes
in with considerable velocity. The water rises in the pit through
the sluice, to the height of two feet, and is then discharged
through some means not yet ascertained. Mr. Babbage said that the
waters which disappeared might go into vast hidden receptacles not
yet filled up, or else the volcanic agency supplying heat might, as
the waters descended into the earth, cause eruptions.

Professor Wheatstone showed his speaking machine, and explained
the principles upon which this ingenious machine is invented.

The business of the Meeting concluded, by the thanks of the As-
sociation being given to the Presidents, &c., and to the Public Insti-
tutions in Dublin for the accommodation granted to them, and espe-
cially to Sir John Tobin of Liverpool, who gave one of his fine Steam
Vessels, for the conveyance of members of the Association to and from
Ireland.

This terminated the proceedings of the British Association for 1835.

Article IV.

SCIENTIFIC INTELLIGENCE.

I. — Live Toad found embedded in a Stone. By Andrew
Pollock, Esq. f To Dr. JR. D. Thomson. J

16, Capel Street, Dublin, I9th August, 1835.
My dear Sir,
Mr. Sturge of Birmingham, called on me to-day, in the way of
business, and I took the opportunity of learning from him the parti-
culars concerning the live Toad, which was found embedded in stone,
on the new line of Railway betwixt London and Birmingham, and
an account of which, he gave last week at one of the Sectional Meet-
ings of the British Association.

It appears, that the Toad in question, was found in apiece of free-
stone which had in it no perforations or other possible means for the
animal's respiration ; that, on the Toad being discovered by the acci-
dental breaking of the stone, its skin shewed a bright colour approach-
ing to yellow; that in 15 or 20 minutes afterwards, the colour
changed to dark greyish approaching to black ; that it at first appeared
to breathe with difficulty, but gradually shev\?ed more freedom of
respiration ; that it lived for about four days, and probably, would
have lived longer, had sufficient caution been used in avoiding too
great exposure in its new state of existence.

236 Scientific Intelligence. [Sept.

I leave to our able geologists the elucidation of the extraordinary
causes, which originally placed this unexpected visitor in its narrow
cell, involving, as the question does, phenomena of no small interest,
both in a geological and chronological point of view. My present
object is, to submit for consideration, an idea with which my own
mind is pretty freely impressed, and which, I think, derives consider-
able strength from this unexpected discovery ; and it will afford me
much pleasure if the subject is taken up by some able hand, who may
possess opportunity of collecting facts tending to elucidate the case.

The idea I would throw out for consideration (or rather for scien-
tific investigation) is, whether the Toad in question, was not incased
in its stone mansion before the f ally and consequently, at a period of
the world's history, when the atmosphere it breathed was not im-
pregnated with the seeds of mortality.

We have every reason to believe, that many of the fossils found
embedded in the earth, have been so from a period anterior to the
deluge j and we have no proof that any of the animals which have
been found alive in an embedded state, were so placed at any period,
since the very earliest part of our world's history ; moreover, we have
yet had no positive proof that animals would now really exist if
enclosed in stone, clay, or any close substance for a lengthened period.
We seem thus, to be led to something like the conclusion, that the
Toad now brought to view, and other animals found in somewhat
similar circumstances, were actually so placed or embedded, prior to
the change which came upon the world at the fall of man ; and if
this fact be established by satisfactory evidence, are we not justified
in drawing therefrom, a strong proof of the truth of scripture history.
That inspired record states, in simple, but emphatic language,
" Cursed be the ground for thy sake," now, how could this curse,
involving as it does, liability to sickness and death all who breathe
the tainted atmosphere, be passed on the ground (or earth) so natu-
rally, as through the medium of the atmosphere, thus, rendering it
the instrument of carrying the seeds of dissolution round the surface
of the globe.

If we can arrive at the conclusion, that all animals found in an
embedded state, have been so enclosed from a period interior to the
fall of man, if we also find that animals now similarly encased cannot
exist, we thus arrive at a most important fact, namely, a direct geo-
logical proof of the fall, and consequently of the truth of scripture
history.

The fifteen years experiment now in progress for preserving animal
life in an enclosed or embedded state, will tend much, either to con-
firm or disprove this point.

Meantime, I have only to express my firm persuasion, that science
as it advances, will in its brighter and higher discoveries, lead to the
development of that harmony, which ought ever to appear, and I
doubt not, will be found to subsist betwixt the laws of nature, and
the statement contained in the revelation given us by nature's God.

With best wishes, believe me, my dear Sir, yours very truly,

ANDREW POLLOCK.

1835.] Scientific Intelligence, 237

II. — Scientific Association of Germany.'^'
The Annual Meeting of this body is to be held this year at Bonn,
on the Rhine, from the 17th to the 27th of September, At the
meeting last year at Stuttgart, Dr. Christian Freiderick Harles, Privy
Councillor of Prussia and Professor of Medicine in the University
of Bonn, and Dr. Jacob Noeggerath, one of the Directors in Chief
of the Council of Mines for the Rhenish Provinces of Prussia, were
respectively chosen President and Secretary of the ensuing Meeting.

The Committee appointed to superintend the preliminary arrange-
ments have already received notice of the intended presence of several
of the most eminent men of science in Europe.,

The Geological Society of France meets in the beginning of Septem-
ber at Mezieres, and after examining the country there, and around
Namu, Liege and Aix la Chapelle, joins the German Association
at Bonn. The attraction of such an assemblage will be greatly
heightened by the beauty of the country around the place of Meeting,
and the neighbouring Siebeugebirge, Laacher See, and Cifel will
present especial objects of interest to the Geologist.

There will be sufficient time to go to Bonn after the Meeting of
the British Association in Dublin, and we hope that our own country
will be worthily represented in all the departments of physical and
medical science. Those who mean to go will do well to give notice in
due time ; in order that they may not be disappointed as to accommo-
dations. We know that in the true Spirit of German hospitality the
Committee are anxious to provide comfortable quarters for all strangers ;
but the town is small, and therefore they should get as early notice
as possible. Letters should be addressed to Professor Noeggerath.

III. — Remarks on the Temperature of the Baltic. — Extract of
a Letter from Alexander Humboldt to M. Poggendorff,
(Pogg. Ann. xxxiii. 233.)
Peculiar contingencies of an active life have made me sail over the
Pacific and Caspian seas sooner than the Baltic, which lies so near
my native country. In two little voyages which I made lately, in*
the Russian steam-vessel Ischora, from Stettin to Konigsberg, and
in the Prussian steam-vessel, Frederick William, from Konigsberg
to Dantzic and Stettin, I occupied myself entirely with the variations
of temperature at the surface of the Baltic. The phenomenon of an
extraordinary fall of the thermometer, to a point from 48*2 to 51*8
Fahr. appeared to me very extraordinary. Perhaps other observers
may be more fortunate in discovering the cause of this sudden sinking.
While the air on the 24th of August was between 70" '7 and
76„-28 F. from lO a.m. to 7 P-™.^ I found the sea at Swinemunde,
73 '76, and opposite Treptou, 68"- 54. In the bay south of Swine-
munde it was 64o-76. On the 25th, when we were rounding the
promontory between Leba and Rixhofter, where the coast approaches
nearest to the island of Gotland, the thermometer in the sea fell
suddenly to 52°* 16 and 53°-6, the air being 66°*2. We had remained
at the same distance from the coast, varying from 1 J to three nautical
miles (60 to a degree), and the hours of observation were lOj a.m.
and li p.m. I mention the time of the observation and the tempera-
* We insert this notice by request.

238 Scientific Intelligence. [Sept.

ture of the air, although I believe that they have very little influence
on this variation. On the east side of the promontory of Hela the
temperature of the sea rose again to 74*^*16 at 8 a.m. (The air was
67*°10). This degree of heat the sea retained as far as Pillan and
Konigsberg ; and in Frischen Bay, near Pase, its temperature was
as high as 71 -"24, the air being 68° 90.

The same appearances were observed during the return. The sea,
which near Faluwasser at 8 a.m. in four fathoms water, on the 3rd of
September, had only a tenjperature of 64° 04 ; and at 9 a.m. in the
Gulph of Dantzic, in fifteen fathoms, 63o'5, rose opposite Hela to
70°-52, the depth being seventeen fathoms, and the heat of the air
from 68^ to 69 '8. But when we again approached the promontory
between Rixhofter and Leba, the temperature of the sea sunk gradu-
ally to 59°-72, and then to 51°-08. The air was from 63° 5 to 64°'4,
and the time noon and 3 p.m. The difference in the temperature of
the surface of the sea was thus, in the first voyage 68°*54, 52'^- 16 =
16"38; and in the second, 70"*52 — 51°-08 = 19-°44. As we
approached Stolpen, without any change in the temperature of the
sea or the distance from the shore, the temperature of the water
again rose to 62^*6 and 64^4, although the sea was higher, the west
wind stronger, and the temperature of the air had sunk to 59*^. Over
against Riigenwalrle and Swinemunde the thermometer again rose
as high as 68« and 68° 72.

The cause of the peculiar degree of cold at the promontory between
Leba and Rixhofter, is not currents observable on the surface, nor
shallows ; nor can the increase in the north latitude be considered
the cause ; for, to the east, at the promontory near Pillau, we are
nearly under the same parallel, and yet the water is warmer. The
cause lies probably at a distance, beyond the sound, and in the motions
of the lower layers of water, in an obliquely upward direction, as
diminutions of temperature in the atmosphere often depend upon
similarly descending currents. Now, as Horner's experiments show
that, in mean latitudes, the temperature of the sea sinks scarcely
13°-86 at the depth of 100 fathoms, no one will be inclined to refer
the phenomenon under consideration to local causes, in the basin of
the Baltic, which is only from 15 to 40 fathoms in depth.

The entrance of the Polar waters into the deep water strata of
the Sound, offers us a possible cause ; and the length of the time
required in the communication of heat downwards must also, especi-
ally during this hot summer, be taken into consideration. In the
lake of Geneva, when the surface was at 70° '16, at the depth of 150
feet, the temperature had sunk 27^ and in the lake of Annecy, when
the surface was at 57°'92, the temperature had sunk 15°*84*. It is
evident, from these numbers, that the diminution of temperature
depends upon very intricate causes, as in calm water it is more rapid,
in deeply agitated water slower, unless currents bring from a distance
or push up to the surface colder water.

The remarkable shape of the Baltic, and its stretching towards the
north, influence greatly the relative temperature of the north of
Germany, and give to a basin, to a depression in the land, an impor-
tance which, if it were dry, would, from its little depth, scarcely be
* Pouillet, Elem. de Phys. et de Meteorologie, ii. 676.

1835.] Scientific Intelligence. 239

observed. Rennell says, rightly, in his so little used but excellent
work Investigation of the Currents of the Atlantic Ocean, 1832,
p. 25, that inland seas have a higher temperature than the free ocean
under similar circumstances. Captain Gautier, to whom, along with
Smyth, we are indebted for the excellent examination of the JMedi-
terranean, found on the 3d of August 1819, and the 24th of June
1820, the temperature of the surface of that sea, between lat. 38« 46'
and39» 12' to be between 84°-2 and 85o-l, that is 5°-4 higher than
the mean temperature of the West Indian Ocean,* and only i^'S
lower than that of the sea near the equator, as indicated by accurate
thermometers, t

It will be remarked in my above observations, how powerfully the
great heat of the air during this summer, influenced the summer
temperature of the Baltic.

I found in the open sea in the Baltic during a considerable storm
(not in a calm) the temperature 7l"'9(), and near Swinemunde as high
as 73°'76. Rennell, in his atlas on currents, gives us the August and
September temperature of the Mediterranean, between the coasts of
Oran, Grenada, andMurcia 71°'6, and 74°*84, as the usual maximum
of a year. The usual temperature of the Baltic in free and deep sea,
is in August 59^ to 63"'5 (lO^'-S lower than in August 1834), while
in the Sound of Copenhagen, it amounts to 7l°*6 or 74»'66 and in the
Catlega (under the influence of the Atlantic) it scarcely rises to
61"*16.:J At Dantzic the mean temperature of the whole summer
is 62^*42, at Konigsberg 60°*42, as is determined by 18 to 21 year's
accurate observations. At Dantzic, I tind the mean temperature of
the air in the month of August, during the last 6 years 62^*06. If
this is also, as is very probable, the average maximum temperature of
the Baltic, that is the temperature of the surface in the end of August,
which gives the maximum of the year, we recognise in these numbers
the influence of an inland sea. While the winter temperature of the
Baltic sinks to between 35"*06 and 36^*5, the mean temperature of
the same sea between 54 and 544 N* ^' i^ "^^ under 48°-2. The
acute Kamtz also finds for the Atlantic ocean, in lat. 54'^', by calcula-
tion 48''*92, by actual observation 50*^-90. In the Atlantic ocean, the
difference between the mean annual temperature, and the August
temperature (in the north temperate zone,) is somewhat more than
5°-4. § In the Baltic, this difference appears to be 62^-06 — 48"-56=
13***5. In the Mediterranean, Rennell gives for the south coast of
Spain 42-"30 and 43*^2 for the end of August and the beginning of
September. This is again l4o*4 higher than the mean temperature
of the sea in the same latitude. For the winter temperature of the
air at Naples in lat 40" 51' is 50o*4, and the average of the whole
year is 61 -"84; and Palermo in latitude 38« 6' has a winter tem-
peiature of 54°-34, and a mean annual temperature of 63u-32.

The inland seas have in summer a higher, and in winter a lower
surface temperature than the ocean, and in higher latitudes, as for
instance, in the Baltic, which freezes far from its shores, the sinking
of the winter temperature increases.

* Relat. Hist. § iii. chap 29, p. 518.

t Sxir la bande d'eau a plus chaade. 1. c. chap. 28, p. 498,

X Berghaus, Annal iv. 142.

$ Kantz. Lehrbuch der Meteorolo^e ii. 115, 118.

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RECORDS

OF

GENERAL SCIENCE.

OCTOBER, 1835.

Article I.

On Racemic Acid. By Thomas Thomson, M.D., F.R.S-,

&c., Regius Professor of Chemistry in the University of
Glasgow. ( Continued from p. 172. J

XIII. — RACEMATE OF COBALT.

When solutions of racemate of soda and sulphate of cobalt,
in atomic proportions, are mixed together, no sensible
change takes place at first ; but, by degrees, the sides and
bottom of the vessel become covered with a crust of race-
mate of cobalt.

The colour of this racemate is a fine red, with a slight
shade of blue. When heated so as to drive off the water it
assumes a fine deep violet colour, which is permanent. It
is tasteless, yet leaves a disagreeable impression in the
mouth. Its sp. gr. is 1-769. At 60°, 100 water dissolve
O'llS parts of it. The solution has a red colour, though it
contains only 8-^7*^ P^^* ^^ ^^^ weight of salt. 100 of boiling
water dissolve 0*42 of the salt. The solution has a pretty
deep red colour.

To determine the constituents of this salt, 20 grs. of it,
previously dried in the open air, during dry and warm
weather, were exposed for two hours to the heat of 230°.
The colour became violet, and the weight was reduced to
14*76 grs. The heat being now raised, the salt blackened,
gave out an empyreumatic smoke, and at last took fire and

VOL. II. R

242 Ih\ Thomas Thomson on [Oct.

burnt without flame, like tinder, and left 4*84 grs. of pro-
toxide of cobalt. This oxide was strongly ignited, without
any alteration in its weight.

4-84 oxide of cobalt require for solution 9*395 of racemic
acid. Hence, the 14*76 grs. dried at 230° still retained
0*605 water, or very nearly half an atom. The salt dried in
the open air was composed of

1 atom racemic acid . . . 8*25
1 atom protoxide of cobalt . 4*25
4 J atoms of water .... 5*0625

17*5625
But when the oxide of cobalt thus obtained was digested
in water it gave out 0*25 gr. of carbonate of soda = 0*148
gr. of soda. If this soda, as is probable, existed in the salt
united to racemic acid, it would make 0*453 gr. of racemate
of soda. Deducting this, the original salt was obviously a
compound of

1 atom racemic acid . . . 8*25
1 atom oxide of cobalt . . . 4*25
5 atoms water 5*625

18*125
And the salt dried at 230° retained two-thirds of an atom of
water.

XIV. — RACEMATE OF ZINC.

This salt precipitates in powder when concentrated solu-
tions of racemate of soda and sulphate of zinc, in atomic
proportions, are mixed together. It is a soft white powder,
having a slight shade of buff. The taste of it is not strong,
but decidedly similar to that which characterizes the other
salts of zinc. Its sp. gr. is 1*980. At 60°, 100 water dis-
solve 1*067, and, at the boiling temperature, 2*58 of it.
When the boiling solution is cooled slowly, beautiful silky
crystals are deposited. They are minute, flat, four-sided
prisms, having some resemblance to sublimed benzoic acid.

20 grs. of this salt, exposed for two hours to the tempera-
ture of 350°, lost 2*82 grs. of its weight. The heat being
raised and continued for two hours longer, the loss of weight
was 3*14 grs. In another trial 20 grs. lost 4*43 grs., and
became black when in contact with the glass.

1835.] Racemic Acid. 243

When we burn the dry salt in a crucible the zinc is reduced,
and at least one half of it is volatilized, so that we cannot
determine the composition of this salt by ignition ; nor can
we safely trust the loss of weight when heated, as the mea-
sure of the quantity of water which it contains. I there-
fore precipitated the oxide of zinc from 20 grs. of the salt,
by means of carbonate of soda. The oxide of zinc obtained
weighed, after ignition, 6 grs. Hence, the component parts
of the 20 grs. of salt were

Racemic acid . . 9*428 or 8*25
Oxide of zinc . . 6-000 „ 5-25

Water 4-572 „ 4-00

4 water is almost exactly 3 J atoms. From this we see that
the salt, when dried in the open air, contains 3| atoms of
water.

XV. RACEMATE OF CADMIUM.

This salt precipitates when we mix together solutions of
sulphate of cadmium and racemate of soda in atomic pro-
portions. It is a beautiful white salt, crystallized in small
needles. It is tasteless, or nearly so ; its lustre is saline,
and its specific gravity 2-64. At the temperature of 52°, 100
water dissolve 0-105 of this salt. 100 parts of boiling water
dissolve 0-206 of it.

10 grs. of the salt being exposed for an hour to a heat
about 300°, lost 2*4 grs. of weight. The residue being exposed
to the heat of a spirit lamp; became yellow, then black,
burned like tinder, and gave out a yellow smoke, which con-
tained oxide of cadmium. The oxide of cadmium remaining
weighed 3*2 grs. Its colour was rather darker than usual.

The salt being neutral, if we reckon its composition from
the loss sustained on the sand bath, its constituents will be
1 atom racemic acid . . . 8*25
1 atom oxide of cadmium . 8-00
4 J atoms water 5-0625

21-3125

XVI. RACEMATE OF LEAD.

This salt precipitates when solutions of nitrate of lead
and racemate of soda are mixed together in atomic propor-
tions. When washed and dried it is a white powder, with

r2

244 Dr. Thomas Thomson on [Oct.

shining points interspersed, as if it consisted of minute
crystals. It has no sensible taste. Its sp. gr. is 3*168.

At the temperature of 60°, 100 parts of water dissolve
0-021 of this salt ; and 100 parts of boiling water dissolve
0-088 of it.

From the experiments on this salt, described in the
beginning of this paper, it appears that when it has been
dried in the open air, without artificial heat, it is a com-
pound of 1 atom racemic acid . . . 8*25
1 atom protoxide of lead . . 14-
4f atoms water 5*245

27-495
But the greater part of this water is probably only mecha-
nically mixed ; for, when exposed to a heat not exceeding
100° there only remains IJ atoms water, which, therefore,
I am disposed to consider as the whole chemically combined
water which it contains.

XVII. — RACEMATE OF TIN.

When solutions of chloride of tin and racemate of soda
are mixed in atomic proportions a white curdy precipitate
falls, which may be washed, and dried on a filter. It is a
chalky looking powder, which reddens vegetable blues,
and has a slightly sweetish and acid taste.

Its sp. gr. is 2-197. At the temperature of 100 water
dissolve 0*146 of this salt. The matter dissolved consisted
chiefly of racemic acid, though it contained likewise oxide
of tin. 100 boiling water dissolve 0*83 of the salt; and
this dissolved portion contains a greater excess of racemic
acid than the cold solution does, judging from its taste and
appearance.

20 grs. of the salt being exposed for two hours to a heat
of 350°, were reduced to 15*88 grs. This residue was still
white, though it had a slight shade of buff. Being exposed
in a porcelain crucible to the heat of a spirit lamp, it gra-
dually blackened, without melting, and at last caught fire
and left a black powder, which continued for some time to
glow, till it was converted into peroxide of tin, weighing
12-57 grs. Equivalent to 10-1289 grs. of protoxide. If

1835.] RacemicAcid. 245

15*88 grs. had been deprived of the whole of their water by
the heat of 350°, the anhydrous salt must have been com-
posed of

Protoxide of tin . . 8*25 = 1 atom
Racemic acid . . . 4*684 = J atom + -ji^ atom,
or very nearly a diracemate of tin. From the taste of this
salt, and from the effect of water upon it, there seems no
reason to doubt that when first formed it was neutral, but
that nearly one half of the acid had been washed away while
it was on the filter. If we include the water driven off, the
component parts of the 20 grs. must have been

Racemic acid . . . 5*7511 or 4*684 = J a,tom
Protoxide of tin . . 10*1289 „ 8*25 = 1 atom
Water ..... 4*1200 „ 3 355 = 3 atoms

200000

The preceding results not being very satisfactory, I mixed
together solutions of 151*25 grs. of protochloride of tin
crystals, and 122*5 gr. of racemate of soda. The former of
these salts contained very nearly 72 J grs. of protoxide of
tin, and the latter 82 J grs. of racemic acid. A white chalky
precipitate fell, which being collected on a filter, washed
with three successive portions of hot water, and dried,
weighed 119*21 grs.

The first portion of water being evaporated to dryness,^
left a salt in long needles, agglutinated together. It red-
dened vegetable blues, and had an astringent and bitter
taste. It weighed 107*9 grs.

The second portion left a salt having a saline and slightly
acid taste, weighing 23 grs.

The third portion left 8*1 grs. of a similar salt. All these
salts reddened vegetable blues, as was the case with the
chloride of tin which had been employed.

Thus, from 273*75 grs. of the two salts employed, I ob-
tained, in all, 258*21 grs. of new salt. The difference must
have been partly owing to the new salts having been more
dried than the original salts had been. Accordingly, on
dissolving the 107*9 gr. of the salt obtained from the first
water employed to wash the precipitate, and crystallyzing
afresh, the crystals weighed 114*7grs. The additional 6*8grs.
thus obtained make the weight 265*01 grs. There is still a

246 Dr. Thomas Thomson on [Oct.

loss of 8' 74 grs. proceeding from the salts of the second and
third waters used for washing the precipitates which had
been too strongly heated, and were in part charred.

I shall now relate the experiments made to determine
the nature of these salts :

1. The 119'21 gr. of Precipitate. — This was a chalky
powder, precisely similar to that above described. 20 grs.
of it, kept for 2J hours in the temperature of 340°, lost
1 gr. of weight. We see from this that it had been previ-
ously much better dried than the first racemate of tin
examined. Being more strongly heated, it blackened and
burned like tinder, leaving a yellowish powder, weighing
12-79 grs.

This residue was digested in water, and the liquid being
evaporated to dryness, left 0'166 gr. of common salt. Con-
sequently, 12*624 grs. of the residue was peroxide of tin =
1125 grs. of protoxide. Hence, the 20 grs. examined must
have consisted of

Water 1-000

Protoxide of tin . . . 11-250 or 12-23
Racemic acid . . . 7-584 ,, 8-25
Common salt . . . 0*166

20*000
The oxide of tin exceeds an atom by about one-half.

We might, therefore, consider the salt as a subsesqui-
racemate of tin, not quite freed from common salt. I did
not wash it nearly as much as I had done the first precipi-
tate, from a suspicion that I had washed away a portion of
the racemic acid. Hence, the reason of the small residue
of common salt.

It is obvious that the 119*21 grs. of precipitated salt were
composed of

Water 5*9605

Protoxide of tin . . 67*0557
Racemic acid . . . 45*2044
Common salt . . . 0*9894

119*2100
The whole oxide of tin from the chloride ought to have
amounted to 82*5 grs. and the whole racemic acid to 82*5

1835.] Racetnic Acid, 247

grs. We, therefore, want 15*44 grs. of oxide of tin, and
37-3 grs. of racemic acid. Let us see how far these will be
found in the water employed in washing this precipitate ;
The common salt found should amount to 75 grs., of which
we have found not quite 1 gr. in the precipitated salt.

2. 114-7 grs. of Salt from first Washing. — Of this salt
24*9 grs. were heated over a spirit lamp. It melted,
frothed, and boiled up, and, after ignition, left a white
salt, resembling common salt, and weighing 16*3 grs. Be-
ing digested in water 12*3 grs. of common salt were dis-
solved, and 4*264 grs. of peroxide of tin remained = 3*803
grs. of protoxide of tin.

It is obvious that the whole 114*7 grs. of salt would have
yielded Common salt . , . 5Q'QQ

Protoxide of tin . . 17*52
Racemic acid and water 40*52

114*70

3. 23 grs. of salt from second washing. This salt being
treated in the same way produced 11*14 grs. of common
salt, and 6*069 grs. of protoxide of tin. The racemic acid
and water, therefore, was 5*791 grs.

4. 8*1 gr. of Salt from third Washing. — This portion was
accidentally lost ; but, from its appearance, it could not
differ much from the salt from the second washing. It
must have contained all the common salt washing to make
up the 75 grs. Now, this amounts to 6*21 grs. Hence,
the oxide of tin, racemic acid and water which it contained
could only amount to 1*89 grs.

The protoxide of tin exceeds the true quantity by 8*15
grs. I do not know the reason of this; unless we are to
ascribe the apparent excess to a residue of charcoal in the
residue of the salt from the first washing. I had thrown
this residue away before I was aware of the excess. But
the peroxide of tin from the second portion of the water,
before it was treated with nitric acid, contained rather more
than the fourth part of its weight of charcoal. This correc-
tion, applied to the protoxide of tin in the second salt, would
reduce it to 13*39 grs., and, of course, elevate the racemic
acid and water to 44*65. After this correction is applied
there still remains an excess of 4*02 grs., which can only

248 Dr. Thomas Thomson on [Oct.

be accounted for by admitting its existence in the chloride
of tin employed.

It is obvious that the greater portion of the racemic acid
wanting to make up the quantity introduced existed in the
first washings, or rather, in the liquid which had been sepa-
rated by the filter from the original mixture of the salts.

The racemic acid in the second water was not sufficient
to saturate the protoxide of tin. If we suppose it to contain
subsesqui-racemate of tin, like the chalky precipitate, then
the racemic acid in it will be 4*05 gr. and the water 1-741
grs. This, subtracted from the whole racemic acid which
must have been present in the washings leaves 33-3 grs. for
the quantity in the first liquid, united to 13*39 grs. of pro-
toxide of tin. Now, this is almost exactly in the proportion
of 2 J atoms racemic acid to 1 atom of protoxide of tin.

In what way the common salt, racemic acid, and oxide
of tin are united in this curious salt is not very clear ; but
that they form together a compound salt, is obvious from
this, that you cannot procure a particle of common salt
from it by concentrating its aqueous solution. It always
crystallizes in long needles, bearing a stronger resemblance
to nitre than to any other saline substance.

XVIII. RACEMATED SUB-OXIDE OF MERCURY.

This salt is easily formed, by mixing together solutions
of nitrated sub-oxide of mercury and racemate of soda, in
atomic proportions. The racemated sub-oxide precipitates
in the state of a white powder, having a slight mercurial
taste. Its sp. gr. is 2*525. At the temperature of 195°,
100 parts of water dissolve 0*0296 parts of this salt.

20 grs. of this salt being exposed to the temperature of
380°, became black, and lost 0*3 gr. of its weight. From
this we see that the salt is anhydrous. The heat being raised
to rather more than 400°, mercury sublimed in the metallic
state, and a black matter remained, weighing 2*2 grs. It
was still racemate of mercury, or, at least, contained oxide
of mercury united to an acid. The running mercury col-
lected, by simply covering the sak on the sand bath with
an inverted glass, was 10*35 grs.

To determine the composition of this salt, 20 grs. of it
were digested in caustic-potash, and the black matter re-

1836.] Racemic Acid. 249

maining undissolved, was collected on a filter and washed.
When dried on the filter it weighed 15*14 grs. Hence, the
racemic acid combined with it must have amounted to 4-56
grs. Thus, we have racemated sub-oxide of mercury com-
posed of Racemic acid . . . 8*25

Sub-oxide of mercury 27*39

The oxide of mercury should have weighed only 26 grs.
The excess was owing to the impossibility of drying it suffi-
ciently. On making the attempt it was partly converted
into running mercury.

350 grs. of crystallized nitrated sub-oxide of mercury
were digested with 127 grs. of racemate of soda, containing
82*5 grs of racemic acid. The racemated sub-oxide of mer-
cury which precipitated, weighed 332*6 grs.

The residual liquid being evaporated, left 112 grs. of a
light-yellow salt, from which I extracted 4*1 grs. of a yellow
matter, consisting chiefly of oxide of mercury, though it
was not free from racemic acid. The liquid freed from this
matter gave colourless crystals of nitrate of soda, weighing
107*53 grs. It is obvious that a loss was sustained amount-
ing to rather more than 2 per cent. This loss, doubtless,
was owing to some water contained in the 350 grs. of
nitrated sub-oxide of mercury.

XIX. RACEMATE OF SILVER.

This salt may be formed by mixing together solutions of
nitrate of silver and racemate of soda, in atomic proportions.
A curdy precipitate falls, which, being washed with cold
water, and dried on the filter, constitutes racemate of silver.

When thus formed it is white, but becomes black, (pro-
bably by the partial reduction of the silver) when heated.
Its sp. gr. is 3* 168. At the temperature of 100° Fahrenheit,
100 parts of water dissolve 0*268 parts of this salt. In
consequence of this degree of solubility, small as it is, this
racemate is not tasteless, but may be recognized by that
peculiar impression which characterizes the salts of silver
in general.

To determine the composition of this salt 107*5 grs. (5
atoms) of nitrate of silver were mixed with 61 25 grs. (5
atoms) of racemate of soda. The racemate of silver which
precipitated weiglied 97*2 grs. when dried on the filter ;

250 Dr. Thomas Thomson on [Oct.

but by half an hour's exposure to a heat of 290° it was
reduced to 97*1 grs. It blackened at a low heat, when
heated in contact with water.

The residual liquid being evaporated to dryness and
heated on the sand bath, became black at the bottom, and
weighed 63*6 grs.

It is obvious that the whole racemate of silver did not
precipitate when the saline solutions were mixed. For the
whole of the salt, supposing it was in an anhydrous state,
would have amounted to 115 grs. Thus, there were 17*9
wanting. Had the residual salt contained only nitrate of
soda, its weight would have amounted only to 53*75 grs.
instead of 63-6 grs. and it would not have blackened while
drying. This blackening indicates the pressure both of
racemic acid and oxide of silver.

To form an estimate of the constitution of the racemate
of silver, 20 grs. of it were heated over the lamp in a plati-
num capsule. It fused, blackened, smoked strongly, and
finally left 11*7 grs. of metallic silver. Now, 11*7 metallic
silver are equivalent to 12*55 grs. of oxide of silver. And
this quantity of oxide requires for saturation 7*01 grs. of
racemic acid; making, together, 1956 grs. If we admit
the 0*44 gr. wanting to make out the 20* to be water, the
constituents of the salt will be

Racemic acid . . . 7*01
Oxide of silver . . . 12*55
Water 0*44

20*00
This is equivalent to

1 atom racemic acid . . 8*25

1 atom oxide of silver . . . 14*75
J atom water 0*5625

23*5625
The water actually present amounted only to 0*517. It
is doubtful whether this small quantity was chemically
combined, or only mechanically lodged in the salt.

XX. RACEMATE OF BISMUTH.

I attempted to form this salt by mixing together solutions

1835.] Racemic Acid. 251

of 206-4 (10 atoms) grs. of nitrate of bismuth, and 125 grs.
of racemate of soda. A white precipitate fell, weighing
150*55 grs. ; and the residual liquid being evaporated, left
a residue which blackened while drying, and weighed
128-67 grs. There appears a deficiency of 52-18 grs. But
the nitrate of bismuth employed contained 39-375 grs. of
water ; and the racemate of soda contained 2-5 grs. of water ;
so that the real deficiency was 10-3 grs., which must have
been occasioned by the blackening of the residual salt while
drying.

On examining the precipitated salt, it was found to be
partly sub-nitrate of bismuth. When heated to 290°, 20
grs. of it lost 0-7 gr. of its weight. When heated over a
lamp it took fire, burned with sparks, just as a mixture of
nitrate of bismuth and racemic acid would do. It left a
yellow powder, weighing 12-5 grs. These 12-5 grs. of oxide
must have been united with 6-8 grs. of acid. Hence, 10 grs.
of the oxide would have been united with 5*44 grs. acid.
Now, this agrees nearly with one-third atom of nitric acid
and 2^.^ atoms of racemic acid. So that every atom of oxide
in the precipitated salt seems to have been united with very
nearly two-thirds of an atom of acid.

The residual salt contained but little bismuth, (only 5-91
grs.) but it contained much racemic acid, and likewise a
considerable quantity of nitric acid.

It is plain, from these facts, that we do not succeed in
obtaining pure racemate of bismuth by double decomposition.

XXI. POTASH-RACEMATE OF ANTIMONY.

This salt is easily formed by boiling a mixture of equal
weights of bi-racemate of potash and glass of antimony in
a sufficient quantity of water, till the bi-racemate of potash
is neutralized. A yellow coloured liquid is obtained, which,
when properly concentrated, deposites crystals of potash-
racemate of antimony. They are in four-sided prisms,
white, and having a good deal of the aspect and taste of
tartar-emetic.

Its sp. gr. is 2-589. At the temperature of 48°, 100 parts
of water dissolve 4-11 parts; and at the temperature of 130°
the same quantity of water dissolve 14 parts of this salt.
It is, therefore, rather less soluble in water than the tartar-

262 M. Boussingault's [Oct.

emetic. It was reasonable to expect that this salt would
possess the emetic properties of tartar-emetic ; and, upon
giving it to a patient in the same dose, and in the same way
as tartar-emetic is given, I found that it operated precisely
in the same way as tartar-emetic. Upon substituting it for
tartar-emetic, in the Glasgow Infirmary, no difference what-
ever in its action could be observed. It might, therefore,
be used, if any such substitutions should ever become neces-
sary, in place of tartaric acid, in the preparation of this
useful salt.

When heated over a lamp it blackened and burned like
tinder, giving out a little yellow smoke. On analyzing it
in the usual way, I found its constituents to be,

2 atoms racemic acid .... 16*5

1 atom potash 6*0

2 atoms protoxide of antimony 18*0

3 atoms water 3*375

43-875
The quantity of water which I found in an old analysis of
tartar-emetic, was only two atoms. But Mr. R. Phillips
assures us that he found that salt to contain three atoms of
water. If this be the true constitution of tartar-emetic, it
coincides exactly, in its composition, with potash-racemate
of antimony.

Article II.

Ascent of Chimhorazo on the YQth December, 1831.
By M. BoussiNGAULT. ( Continued from p. 45. J

After resting a few moments we found ourselves refreshed
from fatigue. None of us had experienced any of the acci-
dents which so frequently happen to persons when climbing
high mountains. Three quarters of an hour after our arrival,
my pulse, and that of Colonel Hall, beat 106 pulsations in
a minute. We were thirsty, and were obviously labouring
under slight febrile action, but this state was not painful.
My friend was extremely cheerful ; he continued to say
many agreeable things while he was busily occupied in
slietching what he called the i/e// o/ /ce, which surrounded

1835.] Ascent of Chimbm'azo. 253

us. The intensity of sound appeared to me to be diminished,
in a remarkable manner; the voices of my companions were
so modified, that, in every other condition, it would have
been impossible to have recognized them. The trifling
noise which was produced by striking a hammer with full
force upon the rock, struck us also with wonder.

The rarefaction of the air produces generally upon per-
sons who climb high mountains the most marked effect.
On the top of Mount Blanc, Saussure felt a disposition to
sickness. His guides, who were also inhabitants of Cha-
mouni, experienced the same sensation. This state of un-
easiness was increased by moving, or in observing two
instruments. The first Spaniards who ascended the lofty
mountains of America, were seized, according to Acosta,
with nausea, and pain of the bowels. Bouguer had several
hemorrhagies among the Cordilleras of Quito. The same
accident happened on Mount Rose, to M. Zumstein, and
Humboldt and Bonpland, during their ascent of Chimborazo
on the 23d June 1802, felt an inclination to vomit, and the
blood came from their lips and gums.

Although we had experienced great difficulty in breathing,
and great lassitude while descending, when we rested, these
disagreeable feelings ceased to trouble us, and we felt as if
in our usual state. Perhaps our insensibility to the effects
of the rarified air was to be attributed to our previous resi-
dence in the elevated towns of the Andes. After witnessing
the activity in such elevated towns as Bogota, Micuipampa,
Potoxi, (kc, the strength and prodigious agility of the prize
fighters at a bull-fight at Quito, which is situated at a height
of 3,000 metres (9,840 feet,) or young and delicate women
dancing during the whole night in situations nearly as high
as Mount Blanc, where the celebrated Saussure had scarce
strength to consult his instruments, and where his vigorous
mountaneers fell down from weakness while digging a hole
in the snow; when I add that the celebrated battle of
Pinchinca was fought at a height little inferior to Mount
Rose, it will readily be admitted that man may accustom
himself to breathe the rarified air of the highest mountains.

In all my excursions among the Cordilleras I have always
experienced, at the same height, a sensation infinitely more
painful in passing over a place covered with snow, than in

254 M. Boussingaulf s [Oct.

clambering over a naked rock. We suffered much more in
scaling Cotopaxi than in ascending Chimborazo ; because,
on the former, we were constantly on snow.

The Indians of Antisana also assured u& that they felt a
degree of stifling (ahogo) when they walked for a long time
on a snowy plain ; and, I confess, that on considering the in-
conveniences to which Saussure and his guides were exposed
while bivouacking on Mount Blanc, at the height of 3,888
metres (12,752 feet), I am disposed to attribute it, partly,
at least, to the unknown action of the snow. This point
was not so high as the towns of Calamarca and Potosi.^

On the lofty mountains of Peru, in the Andes of Quito,
travellers, and the mules which carry them, sometimes feel,
on a sudden, a very great difficulty in breathing, and fre-
quently the latter fall nearly into a state of asphyxia. This
occurrence is not constant, and in most cases appears to be
independent of the rarefaction of the air. It occurs princi-
pally when the mountains are deeply covered with snow,
and during the prevalence of a calm. It may be remarked
here, that Saussure was relieved from the disagreeable
feelings which attacked him on Mount Blanc whenever a
south-east wind blew.

In America, this state of the air, which affects the organs
of respiration, is characterized by the name of soroche.
Soroche, in the language of the American miners, signifies
pyrites. Hence, they seem to attribute the cause of this
phenomenon to subterraneous exhalations. This is not
impossible, but the influence of the snow affords an easier
explanation.

The feeling of suffocation which I have often experienced
while travelling over snow upon which the sun was shining,
I have been inclined to consider as induced by the vitiated
air which was disengaged from the snow by the action of
heat.

This idea is supported by an experiment of Saussure, in
which he found that the air disengaged from snow contained
much less oxygen than that of the atmosphere. The air

• According to M. Pentland, Calamarca is elevated 4,141 metres (13,582 feet.)
The highest part of the town of Potosi is 4,166 metres (13,664 feet). (The lieights
of the most elevated points of the Andes are according to the same authority ;
Sorate 25,400 feet ; lUimani 24,350 feet, and Chimborazo, 21 ,400 feet.— Edit.)

1835.] Ascent of Chimborazo. 255

submitted to examination was collected from the interstices
of snow found in a large crevice. The analysis was made by
Sennebier, by means of nitrous gas, and was compared with
one of the air of Geneva. The following are the results,
in the words of Saussure : *' At Geneva, a mixture of equal
parts of atmospheric air and nitrous gas, gave twice 1*00.
The air from the snow, determined in the same way, gave,
by one experiment, 1*85, by another, 1*86. This trial, which
appears to indicate great impurity in this air, would have
required experiments to determine the nature 6f the gas
which occupied the place of the oxygen.''^

I had long wished to repeat the experiment of Sennebier ;
for, supposing that it was correct ; admitting that the air
contained in the snow of the mountains possesses less oxygen
than common air, we can conceive how this impure air,
disengaged by the heat of the sun, may, by expanding in
the atmosphere, occasion inconvenience to those who are
obliged to respire it. It was with this view that I filled a
bottle with snow at the station of Chillapullu.

When we arrived at the farm of Chimborazo the snow
was completely fused. The water which resulted from it,
occupied about an eighth of the capacity of the bottle.
Seven-eighths were, therefore, filled with air, proceeding,
in a great measure, from the snow : I say, in a great mea-
sure, because, in filling the bottle with snow, it was impos-
sible to prevent the introduction of a notable quantity of
common air. I analyzed the air from the snow of Chilla-
pullu, with much care, by means of a phosphorus eudio-
meter : 82 parts left 68 of azote. Thus, 14 parts of oxygen
were absorbed. This air, therefore, contained 16 per cent,
of oxygen.

However, if we consider that the bottle, independently
of the air from the snow, contained also atmospheric air,
we shall be disposed to consider this experiment as a confir-
mation of the result of Saussure. And the diflticulty of
breathing upon the ice, when the sun shines upon it, the
soroche of the high mountains of Peru will be explained to
a certain extent, by admitting that the air which surrounds
a glacier is sensibly less pure in the vicinity of the snaw
than that of the atmosphere. The eudiometrical result

* Saussure Voyage dans les Alps, vii. 472.

256 M, Boussii\gauU s [Oct.

which I obtained is certainly not free from objection ; and
I think that new experiments are necessary, to prove clearly
. that the air which I examined was the same as that which
existed in the interstices of the snow.

In order to procure this air it is necessary to retard
the melting of the snow. The air of the flask is found in
contact with the water resulting from the snow, which con-
tains more or less air. Now, we know that in such circum-
stances the oxygen dissolves more readily in water than
the azote does, and that the air with which the water is
saturated contains always more oxygen than that of the
atmosphere.

The air which remained in the phial, and which was the
portion I examined, might, therefore, contain less oxygen,
although, in reality, the air contained in the snow possessed
the usual composition. Such is the objection which may
be made to the result which I obtained. With regard to
that of Saussure, it would be proper, in fair criticism, to
know how the air examined by Sennebier, was extracted
from the snow.

Philosophers who have ascended lofty mountains agree in
saying, that the blue colour of the sky becomes more intense
in proportion to the height. On Mount Blanc the sky pre-
sented to Saussure a deep Prussian-blue colour ; and during
the night, according to his own description, in one of his
bivouacs on the same mountain, " the moon shone with
great splendour in the midst of a sky black as ebony." On
the neck of the mountain the intensity of the colour of the
sky was still very great. Saussure contrived an instrument
for making comparative experiments upon this subject.
From our sf^tion at Chimborazo, the sky which on our
arrival presented a remarkably clear aspect, did not appear
to possess a deeper colour than that of Quito. However,
as I have had an opportunity of seeing the sky almost
completely black, I shall relate the facts simply as they
occurred: when I was in Tolima the sky appeared of its
ordinary colour ; I was then at an elevation of 4,686 metres
(15,370 feet), and, consequently, a little under the snow.
On the Volcano of Cumbul the sky appeared of an ex-
tremely deep indigo ; I was then surrounded by snow :

* Saussure Voyage, vii. 321.

I835.J Ascent of Chimhorazo. 257

for the summit was crowned by a glacier. I may remark,
that, during the time I was ascending, and until I attained
the snow limit, this blue tint seemed much less deep.

On Antisana, before reaching the snow, the sky possessed
its usual colour, but whenever we reached the great mass
of ice, it appeared to have assumed an inky blackness. This
phenomenon struck the negro who carried my barometer
with consternation. In the evening we were seized with
inflammation of the eyes, which rendered us blind for some
days.

Lastly, when I ascended Cotopaxi, I, as well as my com-
panion, wore coloured spectacles. When we had walked
for five hours, over the snow, we halted at 5,719 metres
(18,758 feet.)

The sky then appeared, to the naked eye, not to possess a
deeper colour than that of the plain ; just as upon Chimhorazo
we recognized the sky of Rio Bambo and Quito. I do not
mean to deny that the colour of the sky is not really more
intense on high mountains than at the level of the sea, as
I had no cyanometer. I am rather disposed to admit the
general results obtained by Saussure by means of this instru-
ment. All that I wish to establish is, that this difference
of tints is only perceptible by comparison, and that the
black colour of the heavens, as seen upon the glaciers, is
occasioned by the weakness of the organs of vision ; per-
haps, also by an effect of contrast easily conceived.

The mountaineers who accompanied Saussure on his
memorable ascent of Mount Blanc, afiirm that they saw the
stars by day light. Saussure, himself, was not a witness of
the phenomenon, his attention was directed to other objects ;
but he has not expressed any doubts with regard to the
assertion of his guides.

On Chimhorazo, I may add, on none of the mountains of
the Andes, upon which I attained. a greater elevation than
ever Saussure did upon the Alps, I could never perceive the
stars in the day-time. Several times, and especially at the
station of Pena Colorada, I was situated most favourably
for observing this phenomenon ; as I was placed in the
shade, and at the bottom of a very high wall of trachyte.

During the time that we were occupied in making our
observations on Chimhorazo, the weather was extremely

VOL. II. s

258 M. Boussingaulfs [Oct.

favourable ; the sun was hot enough to inconvenience us.
About 3 o'clock we observed some clouds forming beneath
in the plain ; thunder was soon heard below our station ;
the sound was not intense, but it was prolonged. We
thought, at first, that it was a bramido, a subterranean
noise. Clouds speedily surrounded the base of the moun-
tain ; they rose towards us slowly. No time was to be lost,
for it was necessary for our safety that we should pass the
difficult portion of our journey before being enveloped in
the cloud . A heavy fall of snow, or a frost, rendering the road
slippery, would have sufficed to prevent our return, and we
should have had no alternative but to remain upon the ice.
The descent was difficult. After proceeding 300 or 400
metres (984 or 1,312 feet) we penetrated into the clouds.
A little lower, sleet began to fall, which cooled the air
considerably ; and when we arrived at the place where the
Indian was who had charge of our mules, the cloud poured
upon us hailstones so large as to produce a very painful
sensation when they struck us on the hands or face. At
three quarters past four I opened my barometer, at Pedron
del Almuerzo, where in the morning at nine o'clock, it
stood at mm

457,6 Therm. 50°- F. Air 42°
458,2 „ 40°-6 „ 39

Difference 6

It is remarkable that, at this height, the diurnal varia-
tion of the barometer is inverse, that is to say, that from 9
o'clock to 4, the barometer has ascended instead of de-
scended, as constantly occurs between the tropics. This ir-
regularity, however, is perhaps owing to some accidental
circumstance. I am more disposed to believe this, because,
at the farm of Antisana, I found that these variations were
less extensive than in the plain ; but I have observed, also,
that they took place in the same way.

In proportion as we descended, sleet was mixed with the
hail. Night overtook us on the road, and it was 8 o'clock
before we reached the farm of Chimborazo.

The observations which I have been able to make on this
excursion tend to confirm the idea which I have expressed
in another publication, for I have seen the same phenomena

1835.] Ascent of Chimhorazo. 269

repeated on Chimborazo which I had previously pointed
out in treating of the equatorial volcanoes. It is obviously
an extinct volcano. Like Cotopaxi, Antisana, Tunguragua,
and the mountains which stand, on the plateaus of the
Andes, the mass of Chimborazo is formed by the accumu-
lation of the debris of trachyte huddled together without
any order. These fragments, often of immense size, have
been upheaved in the solid state ; their angles are always
broken off, and there is no indication of their having been
in a state of fusion, or even softened. There is no appear-
ance in any of the equatorial volcanoes of a current of lava.
Nothing has been discharged from these craters, but impure
substances, elastic fluids, or incandescent blocks of tra-
chyte, more or less scorified, which have been often pro-
pelled to great distances.

The base of Chimborazo is formed of a plateau, which
may be carefully studied in the torrent near the farm. Here
I could distinctly observe that the trachyte was not strati-
fied. This rock has a felspar basis, generally of a gray
colour, containing pyroxene and crystals of semi-vitreous
felspar. The trachyte rises up towards Chimborazo. It
often presents considerable crevices, which are larger and
deeper, in proportion to their propinquity to the mountain.
Chimborazo may be said to have caused the plateau on
which it is placed to rise up when it was formed.

The trachyte which forms the greater portion of the pro-
vince of Quito presents little variety. The heaped up blocks
which form the volcanic cones, are similar, in their minera-
logical characters, to the rocks which constitute their bases.
These cones, and steep mountains, have, undoubtedly,
been raised by elastic fluids, which burst forth where there
was least resistance. The trachyte raised by the elastic
fluids, and broken into an infinite number of fragments,
has fallen on the surface. After the eruption, the fractured
rock necessarily occupied a greater space ; all the fragments
could not be returned to the orifice from whence they were
ejected, and have consequently been heaped up under it.
This is precisely what would happen, if, after having formed
a deep pit in a hard and compact rock, we wished to fill it
with the materials extracted from it ; whenever the excava-
tion was filled, while we continued to heap up the matter

s2

M. Boussingault's [Oct.

upon it in a line with the axis of the pit, a cone would hi
formed above it, which would be more or less elevated, in
proportion to the depth of the pit. It is thus, I conceive,
that Cotopaxi, Tunguragua, Chimborazo, &;c., have been
formed.

The elastic fluids, in opening a passage through the crust
of trachyte, after being broken, have formed a communica-
tion between the surface of the earth and considerable
empty spaces existing at a greater or less depth. We may
conceive, then, that the fragment raised at first have sunk,
and filled up these vacuities. Thus, in place of the cone
being elevated above the point of eruption, a concavity has
been produced at the surface of the earth. It is thus, I
suppose, that the crater of Rucupichincha, and the green
sulphur lake of Tuqueres have been formed.

I consider, then, the appearance of the trachyte cones of
the Cordilleras, to have been posterior to the elevation of
the mass of the Andes. These are not, however, the most
recent elevations which have taken place in these moun-
tains. In the vicinity of the highest peaks, and, I may
cite in illustration, Cayambe, Antisana and Chimborazo,
we observe small hills, composed of fragments, but differing
distinctly from the trachyte. The rock is black porphyry.
Its basis, which encloses crystals of glassy felspar, is coloured
by pyroxene. The felspar crystals are often rare, and then
the rock appears like basalt. I have never, however, seen
peridote. Sometimes, however, this rock is compact and
prismatic; sometimes it is scoriform, and filled with cells.
It might be taken for lava, if it were diffused over sufficient
space; but then, it occurs always in pieces which scarcely
attain the size of the fist. This matter has evidently been
produced at a very recent period.

At Chorrera de Pisque, near Ibarra, a beautiful collonade
maybe observed resting on alluviam. In the farm of Lysco
this rock, in its broken state, during its ejection has opened
a passage through the trachyte. This appearance Hum-
boldt considered on Antisana as a current. I have dis-
cussed, in another place, my reasons for differing, in opinion,
with my illustrious friend.

The extinct volcano of Calphi, placed at the bottom of
Chimborazo, consists of this kind of basalt. We visited it

1835.] Ascent of Chimhorazo. 261

on our return to Rio Bamba. In the midst of the sandy
soil which occupies the whole plain of Rio Bamba, we ob-
serve, near the village of Calpi, an eminence of a deep
colour. It is Jana, Urea, (the Black Mountain.) In the
lower part of this small hill, the trachyte may be observed
passing from under the sand. It is of the same nature as
that which supports Chimhorazo . This trachyte appears to
have been strongly acted on, being full of crevices. The
top of Jana, Urcu, which looks to Calpi, is formed of small
fragments of the black rock. It reminds us of the erup-
tion of Lysco. It would appear, even, that at Jana Urcu,
this eruption took place after the deposition of the sand
which whitens the plain ; for its surface, in the vicinity of
the volcano, is strewed with these black scoriform stones.

Our guides, who were Indians of Calpi, conducted us to
a crevice where we distinctly heard the sound of a subter-
ranean cascade, and, judging by the noise, the mass of water
which produced it must have been considerable. . The barren-
ness of the soil, from Latacunga to Rio Bamba, had several
times astonished me. I asked, how do the glaciers, the
elevated mountains, which overhang this soil, not produce
numerous torrents? The dryness of the plateau is only
superficial. It appears certain that the waters of the moun-
tains, after having penetrated into the ground, circulate at
a greater or less depth in the interior of the earth. The
subterraneous cascade of Jana Urcu is a decided proof; and
in several places, while descending the deep chasms which
furrow the alluvial soil of the plateau, numerous springs of
water may be observed.

Near Latacunga, between that town and Cotopaxi, there
exists a depot of water, which was encountered by digging
some yards deep in the conglomerate pumice-stone. It is
called, by the Indians, Tombo Polio. In fact, it is a stream
of subterranean water ; the water is incessantly renewed,
and a current can be distinctly perceived. I found its tem-
perature 18'°8, (65-°8.) The temperature of Latacunga is
15-°5 C. (60°)

On the 21st December, we were, on our return, at Rio
Bamba, where I still rested some days to complete my
observations. On the 23d, after noon, I left Rio Bamba for
Guayaquil, to embark for the coast of Peru. It was in view

M, Balard on the Nature of the [Oct.

of Chimborazo that I separated from Colonel Hall During
my residence in the province of Quito, I had enjoyed his
confidence and friendship. His perfect knowledge of the
topography was of the greatest utility to me, and I had
found him an excellent and indefatigable travelling com-
panion. Both of us had served for a long time in the cause
of independence. Our farewell was affecting : Something
seemed to tell us that we should never meet again. This
sad presentiment was too well founded. Some months
afterwards my unfortunate friend was assassinated in one
of the streets of Quito.

Article III.

Researches into the Nature of the Decolourizing Combinations
of Chlorine, By A. J. Balard.*

Among the remarkable properties which chlorine possesses,
there is one to which manufactures have been much indebted
ever since its discovery, viz. its powerful action upon co-
louring matter.

Scheele first pointed out this character, but it was Ber-
thollet who introduced it as the foundation of a new art.
It was first employed in the gaseous form, then in an aque-
ous solution ; but in both of these states it was observed to
produce noxious efi'ects upon the workmen employed in the
bleaching operations. Berthollet strove to overcome this
objection, and ascertained that, by the addition of a little
alkali, as quick-lime, and even carbonate of lime, or mag-
nesia, the pungent odour of chlorine might be removed from
its aqueous solution without injuring its bleaching proper-
ties. This important observation led him to recommend a
still more convenient method. He observed that, if, in
place of dissolving the alkali in an aqueous solution of
chlorine, a current of the gas was passed through an alka-
line solution, a much greater quantity would be dissolved,'
and the liquid would also possess a stronger bleaching
power. These new compounds were speedily introduced
into the arts ; and, as the first trials were made in 1789, in

• From the Ann. de Chim. Ivii. '225.

1835.] Decolourizing Combinations of Chlorine, 263

the manufactory of Javelle, the new liquid was termed
Javelle water. But in 1798, Knox, Mackintosh and Ten- .
nant, * of Glasgow, substituted lime for the potash, and
thus introduced a solid substance, which came speedily into
general use, under the name of bleaching powdei'.

In 1822 the employment of chlorine was farther extended
by M. Labarraque, who shewed that these bleaching sub-
stances might also be used for disinfecting purposes.

It might be supposed that the nature of such important
compounds would be well understood by chemists. This is,
however, not the fact. Their elementary composition, and
immediate analysis, it is true, are known ; that is to say,
they consist of chlorine, oxygen, and a metal ; but the
experiments of different chemists have proved that, for two
atoms of the first of these bodies, they contain an atom of
each of the others. The question, then is, how are these
three elements combined ?

1. Opinions respecting the nature of the Bleaching Com-
pounds of Chlorine. — Two hypotheses have been broached
by chemists on this subject. According to one opinion,
these compounds are nothing else than chlorides of oxides.
According to another hypothesis, they are regarded as
mixtures of metallic chlorides, with a salt containing a
chlorine acid, possessing less oxygen, in its composition,
than chloric acid, and, therefore, denominated chlorous
acid. By the first supposition, it is conceived that the
chlorine, in acting upon some metallic oxides, combines
with them without decomposing them, so as produce weak
compounds. The gas being thus feebly retained, acts upon
vegetable colours as if it were free ; that is to say, it destroys
them, either by directly combining with their hydrogen, or
by exciting their oxidation by means of the oxygen of the
water. The chlorine, in combining with the hydrogen,
either from the water or colouring matter itself, is converted
into muriatic acid, and, consequently, into a muriate.

In the second opinion, it is supposed that the chlorine
re-acts upon the metallic oxide employed, so as to decom-
pose a portion of it ; that one part of the chlorine unites
with the metal, to form a chloride, and another to its oxy-

* M. £alard terms the lirm erroneously, Georges, Tennant and Knox. — Edit.

264 M. Balard on the Nature of the [Oct.

gen, to be transformed into chlorous acid ; and that the
latter saturating the undecomposed part of the base, forms
a true chlorite.

By this view the product consists of a mixture of a chloride
and a chlorite. The chlorine, in acting upon the metallic
oxides in contact with the water, is, therefore, supposed to
present analogous phenomena with sulphur, which, in the
same circumstances, produces a mixture of sulphuret and
hypo-sulphite. Further, it is conceived that these chlorites,
when brought in contact with putrid or coloured organic
matter, yield up to them all the oxygen of their acid and
base, and are changed into chlorides ; and that it is only
by their oxidating action that they bleach and disenfect.

If we endeavour to resolve the question a priori from
theoretical considerations, we are inclined to regard the
last supposition as the most plausible. In fact, the com-
binations of simple bodies with compound bodies, are com-
mon, and although the hydrates of chlorine, bromine, and
phosphorus, present us with incontestable examples of the
union of a simple with a compound oxygenated substance,
the compounds of this nature are still very limited. It is,
then, good reasoning only to admit the existence of similar
compounds, when the phenomena which relate to their
production cannot be explained by any view consistently
with facts in general. It appears impossible to suppose
that a body which possesses such a strong affinity for the
metals as chlorine, could unite with these oxides without
decomposing them. Observation holds the same language
as theory, and seems to support the theory of the chlorites.

Chemists, in considering that the compounds which we
are considering, possessed the power of dissenfecting and
bleaching like chlorine itself, were obliged to suppose that
this substance existed in such an ephemeral state of com-
bination as enabled it to exercise the same kind of action as
if it had been free. But we have lately been taught that
chlorine and analogous substances are not the only ones
which possess bleaching powers, the same property being-
characteristic of peroxide of hydrogen, and the hyperman-
ganates. Indeed, all the facts with which we are acquainted
would induce us to conclude, that the oxygenated agents are
as well fitted for bleaching as chlorine. Perhaps the view

1835.] Decolourizing Combinations of Chlorine. 265

of some chemists may be correct, that chlorine, in acting
upon coloured bodies in contact with water, produces its
bleaching effect by an indirect oxidation, induced by its
disposition to unite with hydrogen. Welter made an experi-
ment which appeared to decide the question in favour of
the active agent being a chloride of an oxide. This chemist
found that the bleaching power of chlorine was constant
whether the gas was free or dissolved in water, or whether
it was combined with an oxide.

This remarkable fact could not easily be explained, but
by supposing that the chlorine, in each instance, was in an
analogous state. If, therefore, it were admitted that it was
in a state of solution in the water saturated with chlorine,
it would be necessary to grant that it was united with the
oxide in the bleaching compound; or, if the latter was a
chlorite, it was necessary that the solution of chlorine should
be a mixture of chlorous and muriatic acids. Chemists in
general adopted the first supposition. Berzelius, alone,
preferred the second explanation, although it was less
probable.

The experiments of Soubeiran have since thrown light
upon this subject. They proved that the observation of
Welter was only correct with a solution of indigo in sulphuric
acid ; the latter decomposing the bleaching compound, and
setting at liberty all the chlorine which formed it. But, if
a neutral ink or a coloured vegetable infusion be employed,
the bleaching power is not the same ; and we observe that
its influence is increased by setting free the chlorine con-
tained in a solution of the chlorides by means of an acid.

This property, which the decolourizing chlorides possess,
of allowing the whole of the chlorine which they contain
to be disengaged by the action of the weakest acids, such
as carbonic acid, has been regarded as an argument in
favour of the chlorides of the oxides ; and it must be allowed
that the phenomena of decomposition are much more easily
accounted for on this supposition than by the other. Nothing
is more easily conceived than the action of an acid uniting
to a base, and thus disengaging the simple body with which
it formed a temporary compound. But the disengagement
of the chlorine il also readily explained by the hypothesis
of the chlorites : for we can easily conceive that the chlorous

266 ' M. Balard on the Nature of the [Oct.

acid set at liberty by the acids themselves, produces a double
decomposition, by re-acting upon the metallic chlorides,
with which the chlorites are necessarily mixed, in conse-
quence of the mode in which they are prepared.

From this double decomposition will thus result, on the
one side, the oxidation of the metal of the chloride, which
in this new state would saturate the acid employed, like
the base of the chlorite ; and, on the other, a disengagement
of the chlorine gas, which would proceed from two sources,
the chlorous acid and the metallic chloride.

Although this explanation is more complex than the first,
still it is supported by analogous chemical facts. If we
ignite, for example, a mixture of phosphuret of lime and
phosphate of lime, pure lime is the only residue. Phos-
phorus is disengaged, which led to the idea upheld for a
long time, that this mixture consisted of a phosphuret of
the oxide, which is, however, contrary to the fact.

We owe to Liebig some experiments which appear to
support the hypothesis of the chlorides. This able chemist
observed that chlorine can take the place of carbonic acid,
in acting upon the bi-carbonates, and also acetic acid, so
as to form decolourizing compounds. Now, it is difficult
to conceive that a simple body can thus drive away an acid
from its combination with a base. It is more natural to
suppose that another acid overcame the affinity of the acetic
acid ; and this circumstance appears to justify the supposi-
tion of the existence of chlorous acid.

It may appear astonishing, at first sight, that an acid so
weak as chlorous acid, and which may be expelled from its
combinations by carbonic acid, should be able to take the
place of acetic acid ; but we are acquainted with other facts
equally singular : Acetic acid, for example, decomposes
the carbonates, and yet carbonic acid, in acting upon acetate
of lead, precipitates the carbonate and sets the acetic acid
at liberty, which may be distilled over.

Berzelius investigated this subject, and we owe to him an
experiment which, although it has not solved the question,
has thrown considerable light on it. In passing a current
of chlorine through a solution of carbonate of potash, satu-
rated with chloride of potassium, he observed that, at first,
the liquid acquired a strong bleaching powder, and much

1836.] Decolourizing Comhinations of Chlorine. 267

chloride of potassium was deposited. Now, as no chlorate
was deposited, no deutoxide of hydrogen formed, and no
oxygen disengaged, it is necessary to admit that the oxygen
expelled from the metal by the chlorine, was conveyed to a
portion of this simple body, and formed with it some com-
bination containing less oxygen than chloric acid. It is true
that the fact may be explained by supposing that the presence
of the chloride of an oxide in the saturated solution of chlo-
ride of potassium has diminished, in this case, the dissolving
power of the liquid for this salt, and that the salt which is
obtained is only a portion of that which already existed in the
liquid, and is not produced by the action of the chlorine, as
Berzelius supposes. The first explanation is, however, the
most plausible, and leads us to suppose that the metallic chlo-
rides exist already formed in the decolourizing compounds.

M. Soubeiran has confirmed the fact by an experiment
which appears, at present, the only one not susceptible of
objections.

After determining the intensity of the decolourizing
power of a given quantity of chloride of soda, he evaporated
to dryness in a vacuum. He found that during evaporation
cubic crystals of chloride of sodium were formed, which
could be separated perfectly pure ; and that the solid resi-
duum, when re-dissolved in water, and poured into a neutral
coloured solution, possessed the property of destroying
colour, as powerfully as the original liquid.

As this property was not impaired, we cannot admit that
the chloride of sodium was the product of the decomposition
of the decolourizing compound. The chloride of sodium
must, therefore, have existed in the solution before its eva-
poration. Now, if, in acting upon the alkali, the chlorine
had formed chloride of sodium, without the production of
a corresponding quantity of chlorate, peroxide of hydrogen
or oxygen gas, it is obvious that an acid containing less
oxygen than chloric acid must have been formed.

The crystallization of the chlorate of soda in the vacuum
led Soubeiran to hope that he might separate the chlorous
acid; but the prosecution of his researches, announced
nearly three years ago, have not yet produced any publication.

While the question was in this state, it appeared proper
to make new experiments. I conceive that I have been

268 M. Balard on the Nature of the [Oct.

able to demonstrate that the bleaching compounds are truly
saline compounds of a peculiar acid, formed of chlorine and
oxygen. It is the properties of this acid which I have been
able to separate that form the subject of this paper.

2. Mode of preparing Chlorous Acid. — In projecting a plan
for the separation of this acid, it was obvious that this would
be simple, if we could obtain a metal which would form with
the chlorine a compound soluble in water, and the oxide of
which, at the same time, would form with chlorous acid a com-
pound insoluble in this liquid. The same object might also
be effected if we could find a metal which would form with
the chlorine an insoluble compound, and the oxide of which
would unite with the chlorous acid and form a soluble com-
pound. All the metallic chlorides are, however, soluble
in water, except the chlorides of silver, lead, and proto-
chloride of mercury. It was necessary to chose one of these
three : Economy pointed out lead or mercury. But when
a solution of acetate or nitrate of lead is poured into that
of a decolourizing chloride, a precipitate of chloride of lead
is immediately formed, which is susceptible of being altered
by the chlorite. If the liquid is separated it becomes brown,
by being changed into peroxide, and disengages a strong
odour of chlorine. This is obviously produced by the de-
composition of chlorous acid.

Again, when solutions of chloride of lime or soda are treated
with proto-nitrate of mercury, a great quantity of proto-
chloride of mercury is precipitated, and the supernatant
liquid possesses strong bleaching powers, which soon dis-
appear, and we find in the liquid a notable portion of deuto-
chloride of mercury, and the precipitate soon becomes red
and changes into a chloride of an oxide.

Since neither the salts of lead or mercury would answer
the end in question, it was necessary to have recourse to
those of silver. These also present obstacles which it is
necessary should be pointed out :

If we precipitate by neutral nitrate of silver, a solution of
chloride of lime containing a slight excess of alkali, a great
quantity of chloride of silver falls down, together with some
oxide of silver, which communicates a gray colour to the
precipitate. The supernatant liquor possesses very strong
decolourizing powers, which disappear with effervescence

1835.] Decolourizing Combinations of Chlorine. 269

before we have time to filter it. The gas disengaged is
oxygen. I have ascertained in working directly with the
chlorites and oxide of silver, that chloride of silver is formed
and oxygen disengaged ; the latter proceeding from the
chlorous acid and decomposed oxygen. A portion of the
oxygen, is, however, absorbed by the excess of oxide in the
liquid, and is converted into peroxide. In order to obtain
the chlorites free, it is necessary, therefore, to avoid the
precipitation of the oxide of silver, and to operate with the
decolourizing chlorides without excess of alkali, the neu-
tralization being affected by nitric acid, carefully added,
however ; for, if an excess is used, the precipitate of chloride
of silver is speedily raised by the copious disengagement of
bubbles of chlorine, and the bleaching property disappears
in a great measure. If we attempt to separate the chloride
of silver quickly from the liquid, and press it in linen, a
very intense discharge of heat takes place. Direct experi-
ment has proved that chlorous acid, which in this case is
set at liberty, exercises on the chloride of silver the same
action which it produces on the other chlorides, and the
presence of a small excess of nitric acid increases this decom-
position. Hence, perfect neutrality, it is obvious, is essen-
tial. When this has been attained, the metallic chlorine
and alkaline chlorite are decomposed, the chloride of silver
precipitates, and the liquid possesses strong decolourizing
properties, owing, undoubtedly, to the chloride of silver
which remains in the solution. But this substance is very
easily decomposed, and it is impossible, even with frequent
filtration, to obtain a limpid solution. As chloride of silver
is continually depositing, the liquid diminishes in its bleach-
ing powers, and chlorate of potash remains.

This process having failed, it appeared to promise success
to try the action of the oxide of silver upon chlorine itself.
Accordingly, pure oxide of silver was suspended in distilled
water, and agitated with chlorine. The latter was absorbed,
aud the portion of the oxide in contact with the chlorine
formed a white compound, the other portion assuming a
deep black tint. The first was chloride of silver ; the
second, peroxide of silver. In this experiment heat was
given out, but no perceptible quantity of oxygen. The
liquid, immediately after filtration, was limpid, and strongly

270 M. Balard on the Nature of the [Oct.

decolourized, but it retained these properties only for a
short time ; chloride of silver precipitating, and chlorate
remaining in solution.

Analogous phenomena are observed when any salt of silver
is treated with chlorine, as nitrate, acetate, chlorate, <fec.
Chlorate of silver is formed and the acid of the salts is set
at liberty.

Decomposition having rapidly occurred in this, as well
as in former experiments, a method which appeared capable
of arresting it presented itself, viz., to precipitate the base
of the chlorate of silver by chlorine itself. Chlorine, in
acting upon any salt of silver, separates from it the base,
and these two bodies are converted into chloride of silver
and chlorous acid. This fact was observed while using an
excess of chlorine in one of the operations described. The
liquid which is obtained after the separation of the chloride
of silver, by filtration, is not pure chlorous acid ; for, if the
decolourizing compound has been precipitated by nitrate of
silver, besides chlorous acid it will contain nitrate of silver.
If a salt of silver is decomposed by chlorine, the liquid will
contain the acid which was united to the silver, mixed with
chlorous acid. Lastly, when we agitate chlorine with the
oxide of silver suspended in water, the chlorous acid, which
appears to be pure, is mixed with much chloric acid ; for,
when the chlorine is agitated with the oxide, an operation
which, however rapidly done, cannot be completed compa-
tibly with the complete absorption of the chlorine in less
than one or two minutes, a portion of the chlorite decom-
poses, and is converted into chloride and chlorate, and the
latter is decomposed by the chlorine, producing chloric acid.

Fortunately, however, chlorous acid is very volatile, and
capable of being separated by distillation, when prepared
by either of the methods described.

As a high temperature, however, would decompose it,
and as, at the temperature of boiling water, muriatic or
nitric acid, which may be mixed with it, would pass over,
it is necessary to operate in a vacuum, or under a low pres-
sure, and much below 212°. The first products contain most
chlorous acid ; if these are collected and re-distilled, very
concentrated chlorous acid will be obtained. These methods,
however, afforded very small quantities of acid, and it would

1835.] Decolourizing Combinations of Chlorine. 271

have been necessary to give up the examination of the pro-
perties of this substance if I had not discovered a more
economical and productive process. This was by treating
red oxide of mercury, suspended in water, with chlorine
gas. The action of chlorine upon this compound had been
previously examined by Grouvelle, who concluded that the
product was an oxichloride of mercury, very little soluble
in cold water ; and M. Thenard had observed that the liquid
contained in solution, chloride and chlorate of mercury;
but, I supposed that their appearance had been preceded by
the existence of a chlorate of mercury, as occurred with the
silver salts.

The most favourable conditions for isolating chlorous acid
are four : —

1. The action of chlorine upon a strongly alkaline oxide.

2. That this oxide may form a chlorite possessed of a
certain stability.

3. That the metallic chloride formed, may, from its inso-
lubility, be readily separated from the chlorite. 4. That it
may exercise a feeble action upon the chlorous acid, when
we attempt to separate the latter by distillation. The red
oxide of mercury appeared to possess all these advantages.
Accordingly, a greater quantity of concentrated chlorous acid
was obtained by the use of this oxide. The most convenient
method of producing the acid is to pour into vessels filled
with chlorine, the red oxide of mercury, suspended in about
twelve times its weight of distilled water. The absorption is
so very rapid that the glass vessels are often fractured in
consequence of the vacuum formed. If the quantity of
oxide is insufficient, the powder deposited is white, and
chlorine may be observed in the upper part of the vessel.
If the red oxide is added, in excess, the deposit has a red
colour, and the chlorine completely disappears. It is pre-
ferable to operate with a slight excess of oxide of mercury,
in order to avoid a mixture of the chlorous acid with the
excess of chlorine. When the absorption of the chlorine is
complete, the matter contained in the flask should be thrown
on a filter ; the liquid which passes through, when submitted
to distillation in a vacuum, furnishes weak chlorous acid,
but it may be concentrated by a second operation.

(To he continued.)

272 Gustav Rose on Greenstone and [Oct.

Article IV.

On the Rocks which are distinguished by the names of Green-
stone and Greenstone Porphyry. By Gustav Rose.*

The rocks which in geology are distinguished by the names
of greenstone and greenstone porphyry, possess very various
mineralogical characters. There appear to be five different
species, which may be provisionally termed Diorite, Dioritic
porphyry, Hypersthene rock, Gahhro, and Augite porphyry.
These possess the following characters : —

1 . Diorite, — A granular mixture of albite and hornblende.

The albite, as it occurs in this rock, is generally charac-
terized by two cleavages, (P and M), which cut each other
at an angle of about 93°. The first face of cleavage P
exhibits the resulting angle, which is so characteristic of
albite when compared with felspar ; the edge goes parallel
with the second face of cleavage, and by a twin increase,
the granular increments proceed parallel from the second
cleavage face.-f-

Frequently this combination is repeated ; a third individual
being applied on the second, and a fourth upon the third,
&c., so that the third individual has with the first, the fourth
with the second, and also the alternating individuals, among
each other, a smooth stratification. Where, therefore, as
in such cases commonly happens, the individuals of one
layer predominate, they appear as one individual, which is
applied more or less strongly to the first cleavage face,
parallel with the second. Such groups of individuals occur,
combined with each other in accordance with the manner
in which two crystals unite in the Carlsbad twin felspar.
They are likewise united with a second cleavage face ; but
the first, (here always applied faces) lies upon one group

* From Poggendorff 's Annalen, xxxiv. i. [This paper, which is one of great
value, deserves an attentive consideration from geologists. — Edit.]

t Rose states that albite, although found massive, is always radiated, never in
laminae, which distinguishes it essentially from felspar. The planes of cleavage
are situated on the same side, but in felspar on opposite sides in the two crystals.
Sometimes the crystals are united by their planes M , and, consequently, have their
planes on diiferent sides ; but then, the two crystals are attached by their other
faces, to other crystals, in the usual way. — Gilbert's Ann. der Physik, 1823,
St. 2.— Edit.

1835*] Porphyritic Greenstone Rocks. 273

in front, upon the second group behind. This growth,
which consists of many individuals, is often repeated ; the
applied faces changing frequently before and behind with un-
even fracture, so that, in this manner, a single grain of albite
often consists of a great number of regular united indivi-
duals. But the cleavage faces of albite, in the different
varieties of diorite, are not equally perfect ; on the whole,
they are not so perfect as those of felspar ; but frequently,
the fracture is found extending in other directions, and is
fine splintery.

The albite is white, commonly only translucent, and trans-
lucent on the edges ; frequently it is greenish white, probably
coloured by portions of hornblende, and this especially
occurs when the cleavage faces appear indistinct.

The hornblende is doubly cleavable ; the faces cutting each
other at an angle of 124°. It is greenish black, or blackish
green, and opaque. Before the blow-pipe it melts, without
frothing, into a black glass, which is slightly magnetic.

As accidental constituents, the rock contains : —

Quartz, — in grayish or milk-white grains, with more or
less of a greasy lustre.

Mica, — in greenish, or pinchbeck-brown scales.

Iron Pyrites, — in small single hexahedrons, and in small
fine interspersed portions.

Magnetic Iron Ore, — in small fine interspersed pieces.

The proportions in which the principal constituents occur
are different. It seldom happens that albite and hornblende
are found in equal quantities in diorite; usually one or
other constituent predominates, especially the hornblende ;
in which case the diorite possesses a very black appearance,
and the albite appears greenish-white, and very cleavable.
Quartz, mica, and the other accidental constituents, are met
with in subordinate proportions.

The size of the grains of the constituents varies as much
as their proportions. The mixture is sometimes large
granular, as in the diorite of Konschekowskoy Kamen, near
Bogoslowsk, in Ural, where the crystals of Hornblende are
frequently above an inch in length. Similar large grained
diorite exists in the Royal Mineralogical Museum, which
was obtained by Humboldt, from Italy.

More frequently the diorite consists of moderate sized

VOL. II. T

274 Gustav Rose on Greenstone and [Oct.

grains; and when the hornblende predominates, becomes
often very fine granular, and appears to pass into compact
masses.

In diorite where the albite prevails, the hornblende often
lies in single crystals and grains in the granular albite
(Frolowsche Mine, at Bogoslowsk, in Ural), and likewise
in diorite where the hornblende predominates ; the albite
occurs in individual crystals and grains in the granular
hornblende (Turdojak, at Miask, in Ural.) It sometimes
happens, also, that large crystals of hornblende occur in a
porphyritic manner, in a finely granular mixture of albite
and hornblende, (rolled masses in the neighbourhood of
Berlin.)

The different grains of one and the same constituent, as
well as of different ingredients, are difficult of separation.

A portion of diorite, from Alapajeusk, in Ural, consis'ting
of albite and hornblende, the first predominating, weighed
32*0332 grammes, (495i grs.) and possessed a density of
2-792.

The same variety, when heated in a platinum crucible,
melted into a greenish black, and in thin portions, into a
greenish white transparent glass. A variety, very rich in
hornblende, from Nichne-Isetsk, near Katharinenburg, in
Ural, melted, in a charcoal crucible, into a white mass,
translucent on the edges, possessing a fine splintery frac-
ture. At the bottom, an iron regulus was formed, on the
sides of which were seated other small iron reguli. The
large portion contained small crystals, and pieces of tita-
nium, which were easily recognized, by their copper-red
colour, and their remaining undissolved in the solution of
iron in nitric acid. Hence, we see that titanic acid, when it
occurs in minute quantities in diorite, is probably an acci-
dental constituent of the albite and hornblende, as happens
with mica. It does not exist to an appreciable amount in
the diorite of Mapajewsk.*

The diorite occurs under the greenstone of Ural, pretty

* G. Hose considers that to melt titaniate of iron in a charcoal crucible is an
excellent method of separating the iron from the titanium, as titanium is insoluble
in aqua regia. Titanic acid, when fused with bases, forms crystalline products.
Several titanic acid combinations which occur in nature, crystallized, appear to
assume a different form by melting. Yellow titanite forms a black mass, consisting
of rhombic dodecahedrons. Brovsoi titanite, from Ilmengebirge, forms black,
undefined crystals.

1835.] Porphyritic Greenstone Rocks. 275

frequently. It constitutes, in North Ural, the greater por-
tion of the main ridge, and forms the Konschekowskoy
Kamen, at Bogoslowsk, and the Belaja Gora, at Nischne
Tagilsk. Very distinct varieties occur at Alapajeusk, and
in the neighbourhood of Miask.

In other countries, distinct mixtures form the diorite of
Rothenburg am KifFhauser, in Thiiringia, which is fre-
quently large grained ; of Ebersbach, and of the gigantic
pillars in Odenwald ; of Ehrenberge, at Ilmenau, which
contains, also, quartz and mica; of Hodritsch, near Schem-
nity, where pinchbeck-brown mica and flesh-red felspar oc-
cur, and where the considerable silver mine is worked; of
Guambacho, in Peru, of which an excellent specimen exists,
in the collection of Baron Humboldt. Distinct varieties
occur among the refuse of the mines, and among the rolled
masses, at Berlin, which contain milk-quartz as an accidental
constituent.

Diorite, with hornblende predominating, occurs likewise
frequently in Ural, especially in the vicinity of Nischne,
and Werch-Isetsk, near Katharinenburg. It is also ob-
served in the Hartz at Rosstrappe ; at Mahnberg, on the
Ocker ; at Mitweida, in the Erzgebirge, and in many other
places which it is unnecessary to enumerate.

2. Dioritic Porphyry consists of a mass containing albite
and crystals of hornblende enclosed.

The main mass has, in the different varieties, partly a
greenish or blackish gray, partly a greenish or blackish
white, but dull colour ; anun even, fine, splintery fracture,
and is so hard, that it can with difficulty, or not at all, be
scratched with the knife. Before the blow-pipe it melts
into a black ish^green glass .'^

The albite occurs in white, shining, distinctly cleavable,
twin crystals, which exhibit distinctly the angles of perfect
cleavage faces. In some cases the crystals touch each other
sharply ; they are of a greenish or grayish colour, and have
a faint splintery fracture. In other instances they protrude
so slightly out of the basis, that they are only visible when
the mass is moistened.

* Hose has made no trials to determine the nature of the basis of this and' the
following porphyry, but he supposes that it may consist of the substances which
are found crystallized in it.

T 2

^6 Gustav Rose on Greenstone and [Oct.

The hornblende is grayish-black, and has a very perfect
and splendent cleavage. The crystals are long pillars, often
of considerable thickness, more or less strongly united with
the basis. They separate completely from it, and leave
their impression on the surface of its fracture, from which
their form can be determined. Before the blow-pipe small
portions fuse upon charcoal, with great frothing, into a
black bead, which, when not too large, is attracted by the
magnet.

Similar accidental constituents are met with, asindiorite,
viz. quartz, mica, iron pyrites, and magnetic iron ore. Of
these the quartz occurs most frequently, and, in many
instances, in considerable quantity. It is then crystallized
in hexagonal dodecahedrons, with rounded edges, grayish-
white, transparent, and a fatty, splendent lustre.

Albite and hornblende are frequently found enclosed in
equal quantities in the basis, and then, generally in such a
quantity, that the crystals occupy nearly as much space as
the basis. In other varieties the albite or hornblende dis-
appear. Where the albite is present, in small quantity, it
is commonly indistinct.

The sp. gr. of a piece of dioritic porphyry, weighing
32*5866 grms. (501-8 grs.), from Pitatelewsky, near Bogos-
lowsk, where the gold is washed, containing perfect horn-
blende and indistinct crystals of albite, was 2*884.

This porphyry melted in a charcoal crucible into a gray
glass, at the bottom of which iron regulus was formed,
containing, interspersed through it, some titanium, of a
copper-red colour.

Dioritic porphyry occurs in Ural, frequently containing
albite and hornblende in nearly equal proportions, at the
foot of Auschkuls, at the Berkutskaya Gora, near Miask,
and at the gold washing station of Pitatelewsky, at Bogos-
lowsk ; at the last place, with much dodecahedral quartz ;
with distinct hornblende and subordinate albite, at Polo-
kowsky, near Miask, in the Frolowschen copper mine at
Bogoslowsk, and especially at the gold washing station of
Pitatelewsky; with albite, free from hornblende, in the
neighbourhood of Nischne Turinsk. Many American dio-
ritic porphyries, corresponding with those of Pitatelewsky
and the Frolowschen mine, exist in the collections of Hum-

1835.] Porphyritic Greenstone Rocks, 111

boldt, Deppe, Meyen, and Sellow, from St. Felipe, in the
province of Jean de Bracamoros ; from Cuesta Grande de
Misantha, in Mexico ; from the crest of Monte Impossible,
province of St. Fernando, in Chili ; from the neighbourhood
of Gabriel Maxado, and Serpe, in Monte Video. The
splendid dioritic porphyry of Humboldt's collection from
Pisoje, near Popayan, is characterized by the large size and
beauty of the crystals of albite, and the smallness of the
hornblende crystals. Dioritic porphyry, with a gray basis,
large white albite, and small black crystals of hornblende,
(granito amandola) is found in Italy, and at Verospatak,
in Siebenbiirgen, forming the rock in which the gold mine
is worked. The albite is somewhat earthy; the rock con-
tains dodecahedral quartz of a large size, rounded on the
edges.

The dioritic porphyry of Schemnitz, in which the silver
mine is worked, is similar. As accidental constituents,
green talc is met with in regular six-sided tables, and iron
pyrites ; it is mixed with fine calcareous spar, and effer-
vesces with acids, in all parts, as Beudant pointed out.

3. Hypersthene Rock, — a granular mixture of labradorite
and hypersthene.

The grains of labradorite have two cleavages, which cut
each other at the same angle, as in albite. The same com-
binations also occur among them, especially in the large
granular varieties of hypersthene rock, (as at Paul's Island,
coast of Labrador), where the variegated appearance upon
the perfect cleavage faces is a common occurrence. In
these large granular varieties it is grayish-white, very trans-
lucent, and mostly of the well known variety of colour which
appears on the second face of cleavage (M.) In the smaller,
large granular varieties, it is snow-white, strongly translu-
cent on the edges, and without the variety of colouring.
The faces of cleavage are, in this case, imperfect ; the frac-
ture small splintery. In these varieties it is difficult to
distinguish it from similar crystals of albite ; its capacity
of melting i)efore the blow-pipe is equally small ; it does
not change the colour of nickel and borax when it is
fused with these substances before the blow-pipe. Its sp.
gr. is higher, being to albite as 27 to 26. Yet, in the finely
granular varieties of hypersthene rock, this is difficult to

278 ' Gustav Rose on Greenstone and [Oct.

distinguish. Its solubility in concentrated muriatic acid is
greater than that of albite, but the difference is too small to
serve as a distinction.

It does not occur, as far as has been hitherto observed,
either with hornblende or augite ; but, if it vras found along
with these minerals, it would be very easily distinguished.

Hypersthene has two faces of cleavage, which cut each
other at an angle of about 88°, and a third, which forms
with the other angles an angle of 134°; and the blunt faces
shew four-sided prisms. The first faces of cleavage are
generally imperfect ; the last are often complete ; but fre-
quently, in this direction splendent faces occur, which are
not cleavage, but compound faces. These perfect faces, in
reference to the structure, form the distinction between
hypersthene and augite, in which the faces of cleavage are
parallel with the faces of the four-sided prisms.

Sometimes the most complete faces of cleavage of the
hypersthene possess rectilinear boundaries, as in the hypers-
thene rock of Monzon, in Tyrol. They form, then, symme-
trical hexagonals, with two angles of 118°, and four angles
of 121° ; the same angles which occur in augite (r of figure
93 in the 67 copper-plate of Haiiy's Atlas).

The colour of hypersthene is blackish brown, blackish
green to greenish black; in some brown varieties (from
Paul's Island, and from Penig, in Saxony), it is copper-red,
on the most complete faces of cleavage, and the lustre of the
same, metallic, and like that of mother-of-pearl, while, on
the other faces, the lustre is fatty. In other brown varieties
(from Neurode in Sil6sia, Elfdalen in Sweden), the distinc-
tion of the colour is very inconsiderable, and disappears, as
happens with the green varieties (Island of Skye, in Scot-
land), where the lustre of the most perfect cleavage faces is
stronger, and more pearly.

The fusibility of hypersthene, before the blow-pipe, is
small ; minute fragments held on the platinum forceps, fuse
more or less into a greenish black glass, which is attracted
by the magnet, in which state it also is before fusion ; many
varieties are almost infusible.

The granular compound fragments of hypersthene are
frequently on the edges near the labradorite, or on the
verge of small fissures which run through the hypersthene,

1835.] Porphyritic Greenstone Rocks. 279

united with greenish-black hornblende, which has two
faces of cleavage cutting each other at an angle of 124 .
The union of this hornblende with the hypersthene is, how-
ever, regular; because, the main axes of the four-sided
prisms, which the cleavage faces of the hornblende and
hypersthene form, as well as that through the sharp edges
of the hornblende prisms, and that through the blunt edges
of the hypersthene prisms, are parallel. Such is the case
in the hypersthene of Penig, and in many rolled masses at
Berlin, yet not so distinct as in the diallage of gabbro, or
the augite of the augite porphyry, yet to be described, but
is probably of the same origin, and apparently not original,
but proceeds from an incipient alteration of the hypersthene
described. Besides the usual constituents, we meet with

Olivine, which occurs in large grains, of an olive-green
colour (Elfdalen in Sweden). It is distinguished from
hypersthene, by the almost total absence of faces of cleav-
age, its infusibility before the blow-pipe, and its colour.

Mica, in pinchbeck-brown scales.

Apatite, in thin, long, white, six-sided prisms, which are
distributed among the other ingredients.

Titaniate of Iron, in iron— black, metallic, splendent,
magnetic grains, which are distinguished from magnetic
iron ore by the red colour which they impart to salt of
phosphorus when fused before the blow-pipe.

Iron pyrites, intermixed, generally in small quantities.

The hypersthene rock occurs in greater or smaller grains ;
sometimes the diameter of a compound grain exceeds several
inches ; at other times, it is so finely granular as to appear
almost homogeneous. In general, the mixture of labrado-
rite, predominates over the hypersthene. Olivine and iron
pyrites, where these ingredients occur, are present only in
very small quantity. Titaniate of iron, on the contrary, is
found in many varieties of hypersthene, so abundantly as
to present the appearance of being an essential constituent
(Elfdalen, and rolled masses, in the vicinity of Berlin).
In other varieties, it is entirely absent (Paul's Island).

The hypersthene rock of Elfdalen, which contains much
titaniate of iron interspersed through it, melts in a charcoal
crucible into a grayish black mass, on the bottom of wliich

280 Gustav Rose on Greenstone and [Oct.

is a large portion of iron regulus, with many perfect crystals
of titanium interspersed through it. Small iron reguli,
with titanium, appear on the surface and sides.

Hypersthene rock occurs in Ural, in scarcely distinct
varieties, and also in rolled masses, in the platinum sand
of Nischne Tagilsk. To the known, coarse granular
varieties, the hypersthene rock of Paul's Island on the
coast of Labrador, belongs ; from which locality, both the
constituents of the rocks were first made known. The
hypersthene found there is characterized by its metallic,
almost copper- red, pearly lustre ; the labradorite is grayish-
white, very translucent, and has a frequent display of co-
lours. This hypersthene rock contains no accidental
constituents.

The hypersthene rock of Penig, in Saxony, is also coarsely
granular ; the labradorite is transparent ; the hypersthene
has a metallic, pearly lustre, and frequently is bordered by
hornblende. Somewhat less coarsely granular is the hy-
persthene rock of Buchau, at Neurode, in Silesia, the labra-
dorite being frequently very translucent, and the hypers-
thene brown. The hypersthene rock of Elfdalen consists
of similarly equal sized grains ; the labradorite is white,
and slightly translucent ; the hypersthene blackish brown.
It contains much titaniate of iron, and besides, some olivine
and fine needles of apatite.

At Elfdalen it is worked into vases, often of considerable
size, and other ornaments. For the fine polish of which
this stone is susceptible, and the contrast of the colours of
its constituents, it is scarcely surpassed by any known sub-
stance. Many varieties of hypersthene rocks, among the
rolled masses, near Berlin, are similar to the Elfdalen rock ;
the labradorite is, however, more translucent and some-
what greenish coloured ; the hypersthene, slightly dark,
but very splendent. It contains titaniate of iron as well as
olivine. Other varieties have blacker hypersthene, and
are frequently bordered by hornblende.

The hypersthene rock of Mongon, at Fassa, in Tyrol,
occurs frequently in coarsely granular varieties. It consists
of white, slightly translucent labradorite, and brown hy-
persthene ; the first is predominant, and the hypersthene

1835.] Porphyritic G^reenstone Rocks. 281

lies often in single, regularly defined crystals in the labra-
dorite.

The hypersthene rock of the Isle of Skye, is well
characterized. The Royal collection contains excellent
specimens, procured by H. H. Dechen and Oeynhausen.
The rock is very coarsely granular ; the quantity of hypers-
thene almost predominates, which has never the common
brown, but a blackish-green colour; the labradorite is
greenish-white, and translucent. Titaniate of iron occurs
in it, but in small quantity.

In the Hartz the hypersthene rock is very frequent, and
forms the greatest portion of the greenstone which occurs
there : Yet the different varieties can be scarcely discrimi-
nated, even in the most distinct specimens ; the labradorite
is opaque and greenish-white; the hypersthene brown.
Larger crystals of labradorite lie frequently in the small
granular mass, which also contains titaniate of iron and iron
pyrites. To these distinct varieties belong the hypersthene
rock of the Petersklippe, in the vicinity of Buchenberg,
near Wernigerod ; of Heinrichsburg, near M'agdesprung,
in Selkethale; of Huththale, near Clausthal ; and of KoUie,
near Braunlahe (Nos. 63 and 64 of Lasius' Collection of
Hartz Minerals). These species of rocks resemble those of
Krotenmiihle, near Steben, in the Fichtelgebirge.
CTo be continued. J

Article V.

On the Phenomena of Accidental Colours. By M. Plateau.
C Abridged from the Annales de Chimie et de Physique,
tome. 53, p. 386. By Charles Tomlinson, Esq.)^'^

[1 .] *' We must regard, as entirely unsatisfactory, the theory
of accidental colours most generally admitted, namely, that

* Although the Editor, in the last Number of this Journal, has given an epitome
of this theory sufficient to convey a general idea of its nature, yet, when a theory
is to be discussed and examined, it is necessary the Author should be heard. But,
lest it may be thought by some, that too many pages in the present Number are
devoted to this subject, I have been induced to divide the translation of this paper
into two parts. The first part, now inserted, is a necessary accompaniment to my
own paper. The second part will be published next month, when Ihope to be
able, time and health permitting, to continue the investigation*— C. T.

282 M. Plateau on the Phenomena of [Oct.

the portion of the retina which has, for a certain time,
received the impression of a certain colour, has become less
sensible to the rays of that colour, and that its sensibility
becomes relatively greater to the rays which form the com-
plementary tint.

[2.] *' It is necessary for me to cite here, in favour of my
opinion, only one single fact, stated long ago, but totally
forgotten, that accidental colours may be seen in perfect
darkness, when, consequently there exist no luminous rays
which can produce the sensation of the complementary tint.
[3.] " Accidental colours result from an opposite state
which the retina spontaneously assumes after the cessation
of direct impressions.

[4.] " Accidental colours may be seen independently of
the immediate action of light : that is, that they result from
a spontaneous modification of the retina, and that such is
the case the following are proofs : 1st, This opposition is
evident, as in the case of Mack, which follows the contem-
plation of a white object ; and secondly,

[5.] " That the accidental colours of impressions destroy
direct corresponding impressions. If we observe for a suf-
ficient time, a small piece of red paper on a black ground,
and afterwards direct the eyes to a large piece of red paper,
the space occupied by the image of the small piece of red
paper will appear somewhat Mack, (noiratre), without any
mixture of red: Thus, the direct impression, rec?, is here
destroyed by the accidental impression, green,

[6.] " In cases where the combination of real colours
produces white, the combination of accidental colours pro-
duces the opposite of white, namely. Mack. For example,
while two real complementary colours produce, together,
white, two accidental complementary colours produce, to-
gether. Mack. This may be proved by experiment. By
placing, on a black ground, two square pieces of coloured
paper, the colours being complementary to each other, such
as a red and a green, the centre of each piece being marked
with a black dot. Then, if the eyes be directed from one
of these dots to the other, and so on alternately, for a suffi-
cient time, the result upon the retina (le fond de I'oeil) will
be the formation of an image, by the superposition of the
accidental green, produced by the red square; and of the

1835.]

Accidental Colours.

283

accidental red produced by the green square ; or, in other
words, by the superposition of two accidental colours com-
plementary to each other. If, then, the eyes be suddenly
and completely covered, by means of a handkerchief, this
image will appear perfectly black, having on its right a red
image, and on its left, a green image, (supposing that the
red and green squares are placed as in the figure) :

Fig. 1.

Red. Green.

[7.] Thus, accidental colours do not result from a simple
diminution in the sensibility of the retina, but they are new
sensations, of an opposite nature to the direct corresponding
sensations.

In order to designate more clearly the two kinds of oppo-
site impressions, I shall generally call accidental colours or
impressions, negative impressions, and real colours, or direct
impressions, 1 shall call positive impressions, or colours.
{To be continued. J

Article VI.

On the Theory of Accidental and Complementary Colours, with
Additional ^Experiments and Observations, By Charles
ToMLiNSON, Esq.

1. In two papers already published in this Journal, (vol. i.
p. 439, and vol. ii. p. 21), on Accidental and Complementary
Colours, I stated that my experiments were at variance with
the existing theories of this interesting branch of optics ;
and that I was aware of the existence of a new theory, by
Monsieur Plateau, which I had not seen. Recently, how-
ever, through the kindness of the Editor of this Journal,
I have perused M.. Plateau's paper, which it is my present

284 Mr. Tomlinson on the Theory of [Oct.

intention to consider; and, as I am not aware that it has
yet appeared in any English dress, except the short epitome
of it given by the Editor in the last Number, and taken
from a subsequent paper of the Berlin Professor, I have
inserted it above, in a somewhat abridged form, retaining,
nevertheless, M. Plateau's own language ; and I have taken
the liberty to number, in square brackets, the paragraphs
of his paper, for the sake of convenient reference ; and, as
this paper will form the subject of several papers of my
own, as also of one by my friend Mr. George Dodd, I thought
it important to insert the preceding paper as our text, and,
whenever we employ a figure enclosed by square brackets,
we must be understood to refer to a corresponding para-
graph in M. Plateau's paper, the references to subsequent
parts of our own papers being indicated in the usual manner,
by circular brackets.

2. There cannot, I think, be much hesitation in conclud-
ing with M. Plateau [1.] that the generally admitted theory
of accidental colours is unsatisfactory ; but, in rejecting
this theory, he has not, as I shall endeavour to shew,
offered a better. It is true that his theory is simple, but it
is also unsatisfactory, and my objections may, perhaps, be
included in this one, namely, that accidental and comple-
mentary colours can and ought to be seen together with the
primitive or fundamental colour ; or, to use his own words,
with the direct impression. Still, as any speculations
coming from so ingenious a philosopher as M. Plateau
ought not to be rejected, except on good and sufficient
ground, I have had no hesitation to offer for insertion in
this Journal a translation of every important part of his
paper, and shall, to the best of my ability, consider the
various conclusions he has drawn from his experiments ;
always premising that, as my object in following Nature is
to admire not less her beauty than her truth, I am sure
that M. Plateau is too excellent a philosopher not to pardon
me if I should endeavour to shew that he, in the pursuit of
Truth, has encountered the encouraging smile of Fancy.
It is also important that this theory should be carefully
examined, because, M. Plateau states that, upon it depends
a number of subsequent results obtained by him on the

I

1835.] Accidental and Complementary Colours. 285

persistance of the impressions of the retina, on irradiation,
juxta-position of colours, &c.''^

3. No theory can, I conceive, be accepted which is founded
on a few isolated facts, and which neither agrees with varia-
tions of those facts, nor embraces other facts, in the same
branch of science, requiring classification. It too often
happens, and I may, perhaps, share in the blame now
bestowed on others, that a theory is framed from a few
observations of phenomena which may be consistent with
the theory, as far as it goes, but when other, and it may be,
less gifted observers, vary previous experiments, or multiply
facts which are in opposition to the theory, there is but one
resource to the philosophic mind, which is to modify or
reject it, and, in the latter case, to seek another ; and
although it may be said, as, indeed, I feel in the present
case, how much easier it is to point out discrepancies in one
theory, than to offer another which shall be free from fault,
still, as theory can only be supported by facts, so facts alone
can disturb or destroy it ; and if, after careful examination,
doubts still exist in my mind as to the truth of M. Plateau's
theory, if I have obtained his principal results as stated in
the preceding paper, by far different and simpler means,
and if these results have not led me altogether to the same
conclusions, my object has been, and is, to prove the non-
existence of oscillations in viewing these colours ; that posi-
tive and negative states do not exist ; and that, consequently,
the analogies upon which he relies with so much confidence,
are misapplied. My purpose, also is to consider the view
taken by P.C. of these colours, and, as he and M. Plateau
somewhat coincide, I must, consequently, state objections
which apply to both. I shall also state, hereafter, a theory
of my own, and shall endeavour to support it by the only
legitimate aid that ought, in the first instance, to be brought
to bear, i. e., direct experiment ; because, I repudiate all
abstract speculations unsupported by facts, conceiving that
they alone ought to support theory, and not, as, unfortu-
nately for science, it sometimes happens, that a theory
should precede observations and facts.

4. My principal objection to the existing theories of acci-

* " Je commencerai par exposer mes id^es sur la nature des couleurs acciden-
telles, parceque de la depend I'intelligence de ce qui doit suivre,"

286 Mr, Tomlinson on the Theory of [Oct.

dental and complementary colours is, that they only apply
to those cases where the retina being impressed in a some-
what fatiguing manner by the primitive colour seeks relief,
as they say, in the accidental or complementary tint. Thus,
it is stated, by way of illustration, that when the eye is fixed
for some time on a coloured object, a red wafer, for instance,
" the part of the retina on which the red rays fall is strongly
excited by their continued action. Its sensibility to red
light must, therefore, be diminished, in the same manner
as the palate, when long accustomed to a particular taste,
ceases to feel its impression."* I cannot admit this reason-
ing ; for, I have already, in my two previous papers on this
subject, shewn, by a variety of experiments, that the primi-
tive and complementary colours may be seen at once, readily
and distinctly, by means of the coloured solutions on mer-
cury, as also by means of the perichromascope.f I shall,
hereafter, state other modes of observation by which these
colours may be instantaneously seen ; and I must now state,
most distinctly, my impression, that in order to observe an
accidental or complementary colour, it is not necessary
previously to prepare or excite the eye, whether in respect
of time or determinate space, by a previous distinct observance
of the primitive colour.

5. Here let me distinguish, and the distinction, is not, I
believe, generally adopted or at all attended to, between the
terms accidental and complementary: By an accidental colour
I mean an impression of a colour, less intense than that pro-
duced by the direct impression, and which may or may not
be seen when carelessly or inattentively viewing the funda-
mental tint ; as, for example, when a red wafer is put into
a letter the accidental green is unlooked for, and therefore,
generally unseen. But when the red wafer is stedfastly
viewed for a sufficient time, a faint green ring begins, and
continues to play around the wafer while the eye remains
excited. I believe, however, that the mind has great influ-
ence in the observance of these ocular spectra,^ as also the

* Library of Useful Knowledge, Optics, p. 47.

t Messrs. W. & S. Jones of Holborn, from whom I hare at various times ob-
tained much excellent apparatus, inform me that they have prepared this instru-
ment for sale.

X See third note to (6.)

1835.] Accidental and Complementary Colours. 287

state of bodily health. In the one case, by practice, and
from a knowledge of an invariable result, I find that I can
get a distinct and complete view of the accidental tint almost
immediately after regarding the fundamental colour, whereas
I have employed unpractised persons, whom I shall arrange
into four classes, to look for accidental tints, and the results
of my observations I may be allowed to state thus : —

1. Persons with acute perception of colour.

2. Those with an indifferent, that is, not acute perception

of colour.

3. Those with a positively bad perception of colour.

4. Where the perception of colour is absent.

The persons in the first class are two artists in oil colours,
(one eminent in his profession, but whose name I do not
feel myself at liberty to mention), and amateur artists con-
sisting of several ladies and gentlemen who have obligingly
made observations for me. In all these instances the per-
ception of the accidental tint was more or less ready, though
not so ready as that obtained by the eye employed in the
almost daily observance of these phenomena.

The second class includes persons not engaged in the
practical observance of colour, and hence I term their per-
ception indifferent. They have generally required a longer
time than persons in the first class to obtain a sight of the
accidental tint.

In the third class the observers have obtained the
accidental tint with great difficulty, and sometimes not
at all.

In the fourth class I have been able to make but one
observation. It is the case of a gentleman in a scientific
institution in London, with whom I passed a few pleasant
hours last July. On beginning to converse with him on
the subjects of sound and colour, he desired me to omit the
latter ; and from him I ascertained, for the first time, his
utter incapability to distinguish any colour except deep
black, and blue, and he often mistook the one for the other,
and bright white. On offering him a disk of green glass
he said it seemed to him to resemble grass ; but the disk
was by no means of that shade ; and on holding up light
blues and reds, &c., he declared his inability to name any

288 Mr. Tomlinson on the Theory of [Oct.

one, without incurring the risk of being laughed at, which
he by no means desired.*

In the case of bodily health and affections of the eye, I
have found that, with headache, or slight fever, and some-
times with catarrh, or from too long sitting to books or
writing, from stooping, in short, from any causes which
distend the minute vessels of the retina, &c., with blood, I
have seen the accidental tint on once gazing on the primi-
tive colour, when my mind has even been engaged on very
different subjects. Hence, I presume, the term accidental
to arise, from the circumstance of a colour being seen by
accident, during the observance of the fundamental tint, or
from the colours being supposed accidentally to accompany
the fundamental tint.

6. By a complementary colour, I intend the second colour
produced by various peculiar means, generally differing
from those employed to obtain accidental colours, and differ-
ing from these latter in one distinct point, namely, intensity;
for, while the accidental tints are comparatively faint and
shadowy, the complementary tints are equal in intensity to
the fundamental colour whence they are derived. Both
accidental and complementary colours are obtained by the
observance of a fundamental colour ; but there is, again,
this difference, that accidental tints may be observed when
the eye is in total darkness, which I do not believe to be
the case with complementary tints. (7), [4.] Thus, nearly
all the second colours mentioned in my former papers f are
complementary colours, 2i\though I have carelessly confounded
the two terms, which shews the necessity of accurately
stating the difference between the two, which difference is
founded on my own views of this subject, which may be
thought by some to be peculiar. Nevertheless, I believe
that the distinction I have drawn is strictly correct, inde-
pendent of this inquiry. Another important difference,
which I shall discuss hereafter, is stated to exist, namely,

* It may be interesting to phrenologists to notice that, in the first class, the
organ of colour was prominent ; in the second, good, but not full ; in the third
bad, but not wanting ; and in the last instance it was absent.

t See the tabular list at page 23 of this volume, where the second, or comple*
pentary colours are termed " Ocular Spectra/'

1835.] Accidental and Complementary Colours. 289

that if a fundamental colour, be combined with a colour
complementary to it, that is, an accidental colour equal in
intensity to the fundamental, white will result ; whereas,
if a similar combination be made between two accidental
impressions resulting from two fundamental , colours, the
result will be black. I need scarcely remark that the term
complementary is derived from the Latin compleo, the com-
plementary ^/Zzw^ up that which is wanting in the primitive
tint to produce white. So that two colours are said to be
complementary to each other which, by actual combination,
produce white. (12.)

7. There is no doubt that, under circumstances in which
the eye may be employed, that organ can, to a certain extent,
exercise its function in total darkness. I cannot agree that
the fact has been, as M. Plateau states, either overlooked
or forgotten. The various experiments on the persistance
of the impressions of the retina, on the pressure of the eye-
ball, and many cases of disease of the organ, prove to the
contrary ; and the fact itself is certainly as old as Newton,''*'
that the image of a highly luminous object has been, from
time to time, revived on the retina, days, months, and even
years after the direct impression, even when the eye has
been in total darkness. In the case of pressure of the eye-
ball, colours may be observed in perfect obscurity ; and the
fact is not new, that on gazing on a primitive colour, and
then immediately covering up the eye, or placing it in dark-
ness, the accidental colour is seen. And even more than
this, the case has frequently occurred to myself, where an
accidental impression has been produced on the retina a
considerable time after the cessation of, or rather, after the
removal of the object producing the first impression. Of
these cases, I need only detail one of recent occurrence :

* " Though I looked upon the sun with my right eye only, and not with the
left, yet my fancy began to make an impression on my left eye as well as upon my
right ; for, if I shut my right eye, or looked upon a book, or the clouds with my
left eye, I could see the spectrum of the sun almost as plain as with my right
eye." * * * * " Yot some months after, the spectrum of the sun
began to return as often as I began to meditate upon the phenomena, even tliough
I lay in bed at midnight with my curtains drawn." — Newton's Letter to Locke,
quoted in Brewster's Life of Newton, page 315. The whole of this interesting
letter applies to my present subject, and is peculiarly valuable, in a philosophical
point of view ; it is only to be regretted that Newton should have been so laconic,
and not have particularized the colours of the first, as well as of the subsequent
impressions, if any such there were.

VOL. II. U

290 Mr. Tornlinson on the Theory of [Oct.

I was engaged a portion of one evening a few weeks
since, on experiments on colour, after which I delivered a
lecture on combustion", wherein I had to exhibit the red fire
of the theatres, which burned vividly and brilliantly ; and,
after the lecture, I retired to bed somewhat fatigued, my
thoughts being occupied with the subjects that had engaged
them previous to the lecture, in mentally contriving various
forms and shades of the favourite green colour, for the next
evening's investigation. I had been in darkness above an
hour, and was probably just falling asleep, when I was
aroused by a vivid impression of the forms I had just before
determined in my mind, but the colours were not green,
but red, wearing a cloudy phosphorescent hue, and standing
out, a foot or two, apparently, from my eyes. As I am not
aware of any disordered action of my eyes, except an imper-
fect vision as to distant objects, generally large pupils, and
a sligl^t affection of amaurosis in the left eye, I can only
explain the above phenomenon on the assumption that the
♦active impression of green in the mind, re-produced on the
retina the accidental impression of the fundamental tint. The
eyes, too, might have been, and probably were, fatigued by
the lecture, and the influence of the impression of the red
fire, combined with the employment of the eye previous to
to the lecture, must not be forgotten ; but, being very often
(once or twice a week) engaged in delivering chemical lec-
tures, I generally bestow but little attention on the effect
of brilliant experiments on my eyes. As I do not admit the
necessity of the oscillations of the retina, insisted on by M.
Plateau, in viewing these colours, I only admit his "impres-
sion according to time," with considerable modifications.

8. In employing the red fire^ in my lectures, it has been

* By a curious coincidence, the materials for the production of red fire are,
when properly mixed, a dark-green 9olour. I am not at piesent aware that any
importance is to he attached to this remark, hut a numher of analogous facts will
crowd upon the mind of the chemist, such as the alkalized oxide of manganese,,
wliich is of an opaque green colour, and when thrown into water produces a dark
transparent green, which speedily changes to red ; and I may mention, generally
the red and green hues, as in this case, indicative of the presence of manganic and
permanganic acid. The chemical compounds of oxygen and nitrogen, and the
interesting changes of colour produced hy saturating nitric acid with the binoxide ;
the action of nitric acid on copper ; the oxidation of steel, of silver leaf, &c., &c.,
are all familiar instances which suggest themselves to my mind while writing this
note. It will be out of place here to entimerate them further.

1835.] Accidental and Completnentary Colours. 291

remarked to me that although the fire was certainly red
enough, it always left an impression of green. This remark
has been elicited from persons of good general perception
of colour, and I have endeavoured to ascertain, from, them,
whether the green impression has ever been succeeded by
red, and I have always received a negative answer. With
this view I have repeated the experiment alone, and in
company, and the general result of my inquiries has been
unfavourable to M. Plateau's system of oscillations.

9. In considering M. Plateau's next proposition, [3.] we
must carefully bear in mind the difference already stated to
exist between the two species of colour (5 and 6). As I
have already shewn that complementary colours may be
seen together with the fundamental colours, they surely do
not so much differ in their nature as that accidental colours
can onli/ be seen by a previous preparation of the eye. This
preparation, however, it is admitted by P. C. (page 179),
need only be the act of " less than a second ;" and I have
before stated cases (5.) where the accidental tint has been
seen immediately on observing the primitive colour, and, it
seems to me that '* less than a second," as stated by P. C,
and " immediately," as stated by myself, are synonymous
terms. The difference, however, between the two colours,
as stated by Brewster, is that, " if the primitive colour, or
that which impresses the eye, is reduced to the same degree
of intensity as the accidental colour, we shall find that the
one is the complement of the other, or what the other wants
to make it white light ; that is, the primitive and the acci-
dental colours will, when reduced to the same degree of
intensity which they have in the spectrum, and when mixed
together, make white light. On this account accidental
colours have been called complementary colours." Optics,
page 305, and at pages 308 and 309, he seems to employ
both terms somewhat indiscriminately. P.C., also, in his
last paper, (page 172, ante.), does not seem to distinguish
between the two colours. In his notice at the com-
mencement of his paper, of my two papers, he has omitted
the word " complementary," although it forms part of the
title of my second paper,^ and he does not apply either term

• See page 21 of this vol. In the 9th line from bottom, for ** the same," read
«' an."

u2

292 Mr. Tomlinson on the Theory of [Oct.

until we arrive at the note, (page 174), when he twice
employs the term complementary, and twice the term acci-
dental. He then proceeds, (page 175), employing the term
accidental only, and speaks of one image as the accidental
colour of the other ; and does not loose his hold of the term
until he quits the subject of my two papers, and proceeds to
speak of the effect of contrast, &;c. (page 177), when he again
employs the term " complementary," and only towards the
end of his paper does he adopt both terms in such a manner
as to shew that he understands their distinction ; but, ap-
parently, not having quite satisfied himself as to where he
should fix the boundary line, he has, in many instances,
avoided the use of either term, and, in other cases, seems
to have hesitated which to apply .'^ Now, granting for a
moment that M. Plateau would admit (and the admission
is not likely to proceed from himf) that the coloured solu-
tions on mercury, &c., are accidental, and not complementary
colours, his proposition [3.] would be immediately disproved ;
for then, as we have already seen, the primitive and the
accidental tint if such it be ,can be seen together, the moment
the observation is begun to be made, and for a time, how-
ever long or short. The difficulty then is, to distinguish
the accidental from the complementary tint. It seems to
me to rest principally upon the question of equal or unequal
intensity ; and, the above extract from Brewster renders the
difference very small. I believe, however, that there is a
difference between the intensity of the two spectra, when
the plain mirror and green coloured disk are so inclined as
to form a very acute angle, as recommended by P. C.,J

* I am thus tiresome, because I feel the distinction between the terms is, I
should be sorry to say not seen, but I will say, unattended to by many writers.
It is a remarkable fact, that Barlow, in his Treatise on Optics, and Herschel, in
his Treatise on Light, both inserted in the Encyc. Metropol. (Mixed Sciences,
vol. i. & ii.) have omitted mention of accidental and complementary colours,
except in Herschel's admirable exposition of the Laws regulating Polarization,
where these colours are referred to only as they incidentally occur in the pheno-
mena of polarization. Biot, also, is not altogether free from this sin of omission.

t But it will be observed that M. Plateau makes free, and, at first sight, indis-
criminate use of the two terms, accidental and complementary.

X I may state that this modification was not neglected by me, for, in addition
to other results, I obtained some very amusing ones, to be discussed hereafter, in
June last, and which I afterwards had the pleasure of producing to the Editor of
this Journal, in company with Dr. Thomas Thomson, when I was in London the

1835.] Accidental and Complementary Colours. 293

although I do not think the difference is such as to autho-
rize me to employ the term accidental to the second image,
and besides, white is produced where the two images overlap.
But granting, for a moment, that such is the case, and
the apparatus being arranged as just mentioned, let the face
be regarded, its prominent parts, and the red and green are
so distributed as to give the visage, or rather, visages, for
there are two reflections, a most hideous appearance. But
this experiment, as also that with the finger, is not a fair
one, on account of the flesh colour ; let us then hold a nar-
row strip of white paper before the glasses, and, of the two
reflections, the green is certainly the more intense. It must >
not, however, be asserted that the eye is insensible to the
two colours at the same moment, for, indeed, I find, that
from the moment the strip is properly raised, until the end
of the observation, the two colours are seen under the same
precise circumstances. If to this it should again be objected,
that the preparation of the eye is the act of " less than a
second,*' I answer that the objection embraces a point of
time so minute, that it amounts to nothing ; that I have so
arranged the glasses and strip of paper as to make the
observation at any time, and when my eye has been long
disengaged from the contemplation of objects of a green
hue, as would in any way render the accuracy of the expe-
riment questionable, and the results never vary. I have
very much to say on this subject, but having already carried
this paper to no small length, and being anxious to make a
few observations on the other propositions, I must dismiss
the one now under discussion, by stating that, if the red
reflection of the narrow strip of paper, as mentioned above,
be admitted by M. Plateau, to be an accidental colour, and
and that the two reflections can be seen at the same moment,
(and, admitting one, he must admit the other), then his
third proposition is disproved.

10. The consideration of the -opposition spoken of by
M. Plateau, [4.] of black resulting from the contemplation
of white, will, at present, lead me too far, but I shall here-
after consider this point particularly, and need only state

beginning of July. I also beg to take this opportunity of thanking P. C. for his
kind mention of me ; and, though I may object to many of his conclusions, still I
hope that nothing will interfere to prevent the prosecution of his interesting in-
quiry, or to disturb that harmony of feeling so necessary to scientific inquirers,
even though they differ.

294 Mr. Tomlinson on the Theory of [Oct.

here my admission of the fact that black does result from the
contemplation of white ; that while philosophers have been
so long engaged, and so profitably, in the investigation of
the phenomena of light, an immense field of research remains
still, comparatively unexplored, i. e., the immediate consider-
ation of the living eye, the knowledge of the phenomena of
which, compared with that of its rival in utility and beauty,
the ear, is but small. I object to the theory explanative of
M. Plateau's fourth proposition, conceiving that, as the
involuntary adjustment of a healthy eye, the function of
which is not abused by the individual exercising it, depends
upon the harmony subsisting between the retina, the pupil,
and the ciliary nerves ; so by the abuse of the function,
such as the rigid fixation of the eye upon white objects,
whereby a constrained voluntary adjustment is continually
resulting, the organ is overwrought, or overacted on, and
amaurotic affections result, as in my case, (7.) and if per-
sisted in, the power to exercise the function ceases, eventu-
ally, to exist. The manner in which this reasoning applies
to other cases, such as white resulting from the contempla-
tion of black, &c., together with M. Plateau's proposition,
[5.] I propose to consider in another paper.

11. It affords me very sincere pleasure to state that I
consider the next proposition, [6.] tenable, although I think
M. Plateau has made the experiment in support of it some-
what complicated. I do not find it by any means necessary
** to cover the eyes with a handkerchief," after the observa-
tion, or, indeed, with any thing ; nor do I find it necessary
to '* insulate" the coloured squares by employing a black
ground.*

12. Although I agree, to a great extent, with this propo-
sition, yet I have found it necessary to modify it, and, as
the consideration of its various features will lead me to a
greater length than time will now allow of, I think it better
to offer the whole of my experiments and observations in a
separate paper, next month, if possible, than to leave them
imperfect now. I will, therefore, conclude with an account
of two recent experiments which I think interesting, and
upon which I shall enlarge hereafter.

♦ The colours of the grounds employed with the same, and various comple-
mentary doublets of squares, &c., have formed the subject of an extensive series
of observations by Mr. Dodd, which will be published hereafter.

1835.] Accidental and Complementary Colours. 295

1 . Let two semi-circles of coloured paper, a red and a
green, for instance, be pasted upon one surface of a disk of
pasteboard, of about five inches in diameter, and by com-
municating a rapid rotating motion to the disk,* the result
will be white, by the combination of the two tints from direct
impression.

2. Between the green disk and the plane reflector of the
perichromascope, place a portion of sesqui-oxide of lead,
the green disk being really complementary to the colour of
powder, and the red powder will appear black, as black as
lamp-black ; the combination of the two tints being effected
by superposition.

(To be continued.)
Salisbury, Sth September 1835.

Article VII.

On Mali. By Robert D. Thomson, M.D.
C Continued from vol. i. p. 449 .J

I. The first step of the process consists in placing the malt
in the steep, a square chamber, which is lined with stone and
lime, and is usually sunk below the level of the barn floor,
having been previously filled to the proper height with
water .f The malt is allowed to remain here for not less
than 40 hours, by legal regulations. The light seeds which
swim on the surface are skimmed off, and the mass of grain
is levelled, for the purpose of being gauged. The time
during which the malt is allowed to remain in the steep
varies, according to the will of the malster. But the usual
test of its fitness for being removed is the capability of its
extremities being squeezed together between the fingers.

* The accidental iintsofihese fundamental colours may be revived during rapid
rotation. I have considered this, and analogous facts, sufficiently important to
devote a paper to the subject, especially as the fact is easily explained on existing
principles. This paper will appear shortly.

t Professor Lavini finds the composition of wheat as follows: 1. Ripe com
contains 75 per cent, of starch ; unripfe com only 60 per cent. 2. Unripe com
contains ^ of its weight of mucous extractive matter. 3. In unripe com there is
about -g^Qth of gluten ; in ripe com 25 per cent. 4. The albumen is the same in
both. 5. In unripe corn there is a green resin, amounting to about ^^^th, which
is probably converted into gluten and gum as vegetation advances. 6. Both contain
oxides of copper, iron, and manganese. — Meniorie della Realc Accadem dele Scien.
di Torino, xxxvii.

296 Br. R, D. Thomson [Oct.

New barley requires a longer period before it acquires this
property than old does ; and higg attains this consistence
in a shorter period than barley. By this preliminary step
the grain undergoes a partial germination. It absorbs water
and swells ; English barley increasing \ in bulk, Scotch
barely J-, and bigg \.

In less than 24 hours after the grain has been introduced
into the steep, the water begins to acquire a brown colour,
and a peculiar odour. If this water is evaporated to dryness
a blackish-brown residue possessing a disagreeable taste
remains, which consists of extractive and nitrate of soda,
amounting in weight, to ^V^^'xiiy of that of the grain em-
ployed. About -3 oVtt^^ ^^ its weight of carbonic acid is like-
wise emitted, which remains dissolved in the water, and con-
tinues to be disengaged after the grain has been taken out
of the steep. And hence it is, that in ten days the grain not
only looses all its additional weight, but gradually becomes
lighter than at first. Thus, 100 grains of barley become, by
steeping, 135. Exposed to the air for ten days they become
93-8. After a month they weigh 96*4, and after two months
100*8. Edwards, Colin, and Becquerel, have found that by
causing grain to vegetate in water, acetic acid, sugar, and
fermenting matter were secreted. The circumstance of the
it forms of carbonic acid, in this first stage, shews us that
evolution the preliminary step to germination.

The grain, after remaining in the steep, as has been said,
for a period of not less than 40 hours, is drained. It is then
cast, or removed, from the steep to the floor, where it is
spread out in a rectangular form, to the depth of 16 inches,
for the purpose of being gauged ; in this state it remains for
26 hours. The barley in the couch always occupies a greater
space than in the cistern, from the absence of the pressure
of superincumbent grain. This increase, which is very great
in small quantities, diminishes proportionally to the increase
of the quantity of grain. Thus, if 3 cubic inches of barley
are placed in a cylindrical glass jar, graduated to tenths of
an inch, and are covered with water, in 96 hours the swell
will be 0-3 inch, or -^^ of the whole ; but, upon inverting
the vessel so as to shake the grain to the other end, it will
occupy a bulk of 4*2 inches, indicating a swell of more
than ^. ,

1835.] on Malt. 297

On the other hand, when the quantity of grain is very
considerable, it is found that sometimes its bulk in the steep
exceeds that in the couch, but this maybe, in some measure,
owing to errors in gauging. Considering the bulk of grain
in the steep to be expressed by 100, then the greatest bulk
in the couch is 138, the least 110*6, the average 121*6.
The officer of excise takes what is called the best guage,
both in the couch and steep, or he takes the measurement
of the grain when it has acquired its greatest bulk. One-
fifth is subtracted from the bulk thus obtained, and the
number obtained is considered as equal to the quantity of
clean malt produced. The duty is charged accordingly;
whether correctly or not seems doubtful.

During the time that the grain is in the couch, moisture
is exhaled, and a considerable quantity of heat is evolved.
In the course of the 26 hours when it lies untouched the
heat is seldom more than 2° or 3° above that of the barn,
but is considerably influenced in regard to the rapidity of
its developement, by the temperature of the apartment.
When the heat is evolved, oxygen is absorbed, and carbonic
acid given out.

But the absorption of the former soon ceases, if the atmos-
phere over the grain is allowed to remain impregnated with
the carbonic acid, for vegetation cannot proceed under such
circumstances. To prevent the temperature from increasing
with too much rapidity, and for the sake of exposing the
grain to the action of the atmosphere, it is turned upon the
floor, an operation termed flooring^ the depth of the heap
being gradually diminished to three or four inches. In this
way it is turned three or four times a day, for a period of
ten days or a fortnight. During these operations a series
of interesting phenomena occur. When first placed on the
couch the grain is quite dry, but in 96 hours the tempera-
ture increases 10 degrees, and the surface of the husks be-
comes so moist that if we thrust the hand into a heap of malt
in this state it will be wetted, and possess the smell of
apples. This extrication of moisture, or sweating, as it is
termed, continues for a day or two. If the malt be distilled
at this period some spirits are obtained. When the sweating
has commenced, if the grain is not turned frequently the
temperature attains a great height, sometimes rising as high

298 Dr. R. D. Thomson [Oct.

as 80° At the time when the sweating occurs, the roots
begin to make their appearance, each, at first, in the form
of a small white prominence, at the bottom of the seed,
which soon divides into three rootlets, and afterwards into
four, fixe, or seven. Bear and bigg are said to send out
from three to six roots, and barley from four to seven.
When the three roots appear, the apple like odour goes off,
and is succeeded by a smell resembling that of the common
rush when newly pulled. The roots of the malt, as of grain
on a poor soil, in consequence of the absence of resistance,
have a tendency to grow to a great length, not less than
two or three inches.

The great object in malting is to check this disposition,
and prevent them from becoming longer than ^ths of an
inch, which is effected by frequently turning the malt, and
thus preserving a uniform temperature, and an equal exha-
lation of moisture.

Some practical men recommend moistening the grain
on the third or fourth day ; but, according to the present
statutes, such an application is illegal, although it would
appear to be almost indispensable, when we consider that
the process consists in promoting vegetation.

On the fourth or fifth day after the grain has been re-
moved from the steep, and a day after the appearance of
the roots, the plumula, or future stem, termed acrospire, or
anchorspire, by the malsters, shews itself, issuing from the
same extremity with the root, and advancing under the
husk until it reaches the end of the seed, where it pene-
trates through the husk, and assumes the form of a green
bladed grass. The growth of the plumula is at first rapid,
as it reaches on the eighth day rather more than half the
length of the grain. Then it advances with less rapidity,
for a week or more often elapses before it has nearly reached
the extremity of the seed, which is the criterion by which
the completion of the process is guided.

If the internal part of the grain is now examined it will
be found to have undergone a considerable change. 1. It
has become whiter, and the consistence so trifling, that it
readily crumbles to powder when pressed between the
fingers. 2. Although the period during which it lies on
the floor does not exceed twenty days for ale, and ten days

1835.] on Malt. 299

for spirit, yet, the grain on the first day loses 43^ per cent.
8th day 42 per cent., last day 40 per cent. ; or, considering
the weight on the first day to be 1000, on the eighth day it
will be 926, and on the last day 914. The loss during each
day may be estimated at about 3 or 4000th parts. If the
plumula is allowed to advance beyond the extremity of the
seed the loss of weight is still greater, and hence the pro-
priety of checking vegetation at this point.

Bigg is apt to undergo a greater loss towards the end of
flooring than barley, because the plumula vegetates more
rapidly in the former than in the latter.

Much attention is requisite in order to produce an equable
loss of weight, by preserving an equal temperature, and by
turning at the time when the heat appears to be increasing. -
The best malt seems to be made at a temperature of 56°, or
at least between 52° and 60°.

II. The first part of the operation has now been com-
pleted; germination has been induced, and carried to a
certain extent. The next object is to put an effectual ter-
mination to it. The malt is therefore transferred to the
kiln for the purpose of being exposed to a high degree of
heat. The kiln consists of an apartment lined with plates,
full of minute holes, or with wire or hair-cloth. The malt
is spread upon this surface to the depth of from three to six
inches, and a moderate charcoal fire is placed in the cham-
ber below it. The heated air passes up through the malt,
and escapes, carrying with it moisture, and escapes by the
roof of the kiln, where there is a chimney of well-known
structure adapted for its exit.

For some time the temperature is kept as low as that of
the human body, but as the drying advances it is gradually
raised to 140°, or even higher, according as the intention is
to give a pale or a dark colour to the liquor to be procured
from the malt. If the liquor is to be pale the malt is dried
at a low heat, but if brown, like porter, the temperature is
augmented.

Pale malt may have been exposed to a heat of 170°,
according to the experiments of 1803, and when carefully
dried does not lose the power of vegetating. This result
does not agree with the experiments already stated, of
Edwards and Colin, who found that immersion in hot water

300 Br. R. D. Thomson [Oct.

of 167°, and exposure to hot air of the same temperature,
was sufficient to destroy the power of germination. When
the malt has remained from forty to eighty hours in the
kiln, according to the temperature and quantity of malt
employed it is cleaned, while still warm it is trodden upon
by the workmen, in order to break off the radicles or
commings. The malt is then passed through the fanners, or
the rootlets are separated by means of an instrument called
the harp. The malt thus purified weighs ^ less than the
raw grain. In Ireland the loss of weight is estimated at -J.

The real loss may be estimated at 22 per cent. Of this,
14 parts consist of moisture, and are not peculiar to malt ;
so that, in reality, a loss of only 8 per cent, is sustained, of
which 1| disappear in the steep, 3 on the floor, and 3 by the
commings, the waste being J. The bulk of the malt is gene-
rally greater than that of the raw grain ; the average of
English barley being 105 bushels of malt for 100 grain, and
that of the bigg 99. The weight, however, of the malt, is
in the proportion of 75 bushels malt for 100 grain.

We are now prepared to attend to the change which has
taken place during the process of malting. The alteration
which occurs in its chemical composition will be best under-
stood by a comparison of its analysis before and after
malting, by Proust.

RAW

GRAIN.

MALT.

Yellow resin

.

1

1

Gum . . . .

4

15

Sugar . .

.

5

15

Gluten . . .

.

3

1

Starch . .

,

32

6Q

Hordein . .

, ,

55

12

Here we observe that the gum has increased 11 per cent,
and the sugar 10 per cent., thus affording 21 per cent, of
additional fermentable matter. The gluten has diminished
2 per cent. I have little doubt that the original quantity
of starch ought to have been estimated at 8 per cent., and
that hordein consistsmerely of starch, whose properties are
obscured by the presence of gluten. The additional gum
is produced at the expense of the starch, and the sugar
proceeds first from the starch in the form of gum, and then
is transformed into sugar. The mode in which this change

1835.] on Malt. 301

is operated will be readily understood by a comparison of
the constitution of these substances :

STARCH.

atoms.

GUM. atoms.

SUGAR, atoms

Oxygen .

. 49-68*

- 6

- 53-34=6

- 49-38=5

Carbon .

. 43-55

- 7

- 40 6

- 44-44 6

Hydrogen

. 6-77

- Q'5

- Q-m 6

- 6-18 5

From this table we can readily see reason for the facility
with which starch is converted into gum and sugar ; for,
if we mix 1 part of malt, coarsely ground, with 2 parts
of starch and 4 of water, adding 14 of boiling water, and
place the mixture so as to prevent too rapid cooling, the
liquid tastes very sweet in the course of an hour.

The alterations which are produced in the atmosphere
surrounding the grain during these operations are impor-
tant, and are well illustrated by the late experiments of
Saussure.f He observed, in all his results, that, in ger-
mination, azote is uniformly absorbed. Hence, the reason
is obvious why plants do not vegetate so rapidly in water as
in the open air, after having been steeped in that fluid.
324 grains of wheat, previously steeped for 24 hours in rain
water, were placed in atmospheric air in a close vessel :
They began to germinate in 17 hours, and, in 21 hours, an
examination of the air gave the following results : —

be;fore experiment. after experiment.
Azote . . 9-079 cubic inches. Azote . . 9-047 cub. in.
Oxygen . 2-431 „ Oxygen . . 2-283 „
Carbonic acid 0-150

11-510

11-480
In this experiment -032 azot6 appears to have been ab-
sorbed, and -143 oxygen has been removed. Now, the
carbonic acid produced consists of 109 oxygen, +-041 car-
bon. Hence, '034 oxygen must have been absorbed. In
other cases, however, it was found that the carbonic acid
exceeded the quantity of oxygen consumed. Germination
takes place more rapidly in oxygen than in common air, as
is proved by the following experiment of Saussure : four peas,

* Brunner has lately analyzed starch, and found its composition, oxygen 49*428,
carbon 44-095, hydrogen 6-477. 100 parts of starch, boiled with sulphuric acid
and water, were converted into 107-01 parts of dry sugar. — Pogg. i4-«n. xxiv. 328.

t Ann. des Sciences Nat. for Nov. 1834.

302 Br. R. D. Thomson [Oct.

after steeping, weighed 15-43 grs. troy ; they were placed
in oxygen gas. Four other peas of the same weight were
dissolved in an equal quantity of common air. In 18 hours
the radicles in the oxygen were -078 inches in length, while
those in the common air were only beginning to appear.
15*43 grs. of wheat placed in oxygen for 48 hours possessed
radicles of -78 inches in length, consumed 15*6 parts of
oxygen and produced 14*7 carbonic acid ; while in common
air the radicles were '62 inches long, and, during their
growth, 12 parts of oxygen and 0-3 azote were consumed,
and 12*2 carbonic acid generated. From these results it
may be inferred, 1st, That grain absorbs oxygen in germi-
nating, whether in pure oxygen or in air, but this absorp-
tion cannot always be observed in air, because it is concealed
by the oxygen contained in the carbonic acid, which the
azote of the air causes it to develope.

2. That, in germination, azote is absorbed.

II. DUTY ON MALT.

A tax on malt appears to have been first imposed in the
reign of Charles I., but was irregularly exacted. In 1697
a duty of 6d. per bushel was imposed, for two years and a
half, at a time. Subsequently it was only granted from year
to year, and hence, was called the annual malt tax. In
Scotland an attempt was made to establish a similar duty,
previous to the revolution, which was attended with great
unpopularity. Malt liquor was, therefore, substituted as a
subject of taxation. It is a remarkable circumstance in the
history of the Union, and is one of peculiar interest at the
present time, that no article in the treaty produced so much
discussion as that relative to the malt question. De Foe
tells us, indeed, that the attempt to extend this tax to
Scotland formed an almost insuperable barrier to the union
of the two kingdoms. By the employment of smooth words,
without any decided stipulation against the imposition of
the duty, however, this objection was overruled. The malt
tax being considered in the light of a war tax in England,
was not extended to Scotland till 1713, after the conclusion
of the peace of Utrecht, when, notwithstanding the exer-
tions of the Scotch members to obtain justice for their
country, and in face of the fact which has since been so

1835.] on Malt. 303

clearly developed, that the grain of Scotland was inferior to
that of England, the same duty, it was enacted, after the
24th of June, should be charged in the two kingdoms.
The determined resolution of the inhabitants, however, ren-
dered this attempt at unequal taxation completely abortive ;
for not only were the officers of excise refused admission to
survey and charge the duty, but even the justices of the
peace in all the counties refused to act.

Matters continued in this state, with injury to the inha-
bitants, and a dead loss to the revenue, for 12 years. But in
1725 an act was passed, fixing the Scotch duty at 3d. per
bushel, or half of that imposed in England ; and the same
proportion was observed till 1802. The state of the tax
stands thus from 1760, when a permanent one was esta-
blished in addition to the annual one : —

England Scotland
1760. Additional permanent duty 3d. IJ

1779. Additionall5percent. of ditto - \ -f^ /^

1780. Additional permanent duty 6J ^ 3 -f^

1787. By the Consolidation Act the

perpetual tax became - - - 9| ^i \%

Annual malt tax 6 3

Total before 1802. Is. 3| 7| \%

In 1802 this tax was increased, and in 1803 a still higher
charge was laid on, for the maintenance of war.
The duties then were :

s. D.
English barley malt - - - - 4 4

Scotch barley malt 3 8-|-

„ bigg malt 3 0^

The consequence of the attention to the proper propor-
tioning of the malt duty in the two kingdoms, was that,
instead of the trifling proceeds of 1725, the average of the
malt made annually in Scotland in the 10 years preceding
1803, was 1,924,746 bushels, affording a revenue of about
£137,868.

It is unnecessary to recapitulate the various modifications
which the law subsequently underwent. It is proper, how-
ever to state, that in 1826, an enactment was introduced,

304 Analyses of Books. [Oct.

by which malted barley became chargeable with a duty of
2s. 7d., and malted bear and bigg of 2s. per bushel.

The following table gives the quantity of spirit produced
from grain and malt, and the quantity of grain consumed,
from October 1833, to 1834.

GRAIN. MALT.

England - - . - 4,807,328 gals.

Scotland 3,183,750 — 6,002,422 gals.

Ireland 8,749,794 65,703

Total grain spirits 16,740,872 6,068,125 gals.

Total malt „ 6,068,125

Total to 10th Oct. 1834. 22,808,997 gals.

6,696,344 bushels of grain are consumed in the produc-
tion of spirits in the three kingdoms, and 2,427,248 bushels
of malt.

Article VIII.

ANALYSES OF BOOKS.

The Transactions of the Linnean Society of London,
vol. xvii. part 2d, 1835.

Thb contents of this portion of the Transactions are :

11. A commentary on the fourth part of the Hortus Malabaricus.
By (the late) Francis Hamilton, M.D. &c.

12. Memoir on the degree of selection exercised by plants^ with
regard to the earthy constituents presented to their absorbing surfaces.
By Charles Daubeny, M.D. &c.

13. Review of the order of Hydrophylleae. By George Bentham,
Esq. &c.

14. On Diopsis, a genus of Dypterous Insects, with descriptions of
twenty-one species. By J. O. Westwood^ Esq. &c.

The fact that about two-thirds of the half volume now before us
are occupied with the fourth part of Dr. Hamilton's Commentary,
which, however valuable, has already obtained its full share of the
pages of the Linnean Transactions, must excite regret in those who
are desirous for the prosperity of this very respectable Society, that
its moderate funds should be thus drained, when a contribution from
the ample means which it is well known the author possessed, could
have so readily dispensed with this burden.

The object of the commentary is to remove the discordances in the
nomenclature of Indian botany, particularly with regard to the adap-

1835.] Transactiovs of the Linnean Society of London. 305

tation of the native to the scientific names. The difficulties attending
such an attempt are very numerous and complicated; because the
native names are often indiscriminately applied to various species,
wrhen the latter approach each other in character or quality ; and, in
the east, where the vegetable kingdom is ransacked in all departments
for the purpose of supplying a materia medica to the native physicians,
these obstacles become more multifarious and perplexing than in
more civilized parts of the earth, where, however, it may be alleged
that the physical properties of plants are undervalued. Dr. Hamilton
is inclined to consider the native names properly applied as exhibited
in the following columns, which we have drawn up for the benefit of
our friends in India, where our Journal is already perused :

Manga domestica

Mango Mao, or Mau

Catappa sylvestris

Ada maram

IMyristica Malabarica

Panem palka

Barringtonia racemosa

Samstravadi

Stravadium acutangulum

Tsjeria Samstravadi

Holigarna longifolia

Katou Tsjerou

Myrobalanus S

Tani

Rumphia tilioefolia

Tsjem Tani

Limonia monophylla ?

Mai naregam

Randia virosa

Catu naregam

Limonia acidissima

Tsjerou Catou naregam

Vateria Indica

Paenoe, Paenu

Lansium ?

Nyalel

Alangium decapetalum

Angolam, or Alangi

Hamiltonia ?

Idou Moulli

Sapindus emarginatus

Poerinsii

Duabanga Sonneratoides

Duyabanga Adamboe }

Lagerstroemia hirsuta

Catou Adamboe ?

Eleocarpus perincara

Perin Cara

Mimusops hexandra ?

Manil Cara

Alangium tomentosum

Dhela

Theka ternifolia

Theka

Webera corymbosa

Katou Theka

Clerodendrum serratum

Tsjerou Theka

Cynometra ramiflora

Irlpa

Rhus Odina

Kalesjam

Garuga pinnata.

Catu Calesjam

Schinus Saheria ?

Ben Calesjam

„ Niara

Niyar

Papyrius,or ? j^^egrifolia
Broussonetia ^ ^

Ponga

Vitex leucoxylon

Karil

Cordia ?

Vidi maram

Calophyllum inophyllum ?

Ponna

„ Calaba .''

Tsjerou ponna

Celtis orien talis

Mallam Toddali

„ Amboiensis

Tilayi

VOL. II.

X

306

Analyses of Books.

[Oct.

Acata

Perim Toddali

Kadali

Katou Kadali

Oepata

Rava Pou

Kanjiala, Anavinga

Konijal

Lohajang

Corondi

Bengiri, Hurmayi

Ana Bepou

Bepu

Ban Kongeha

Kari Vetti

Pee Vetti

Sugunda

Noeli Tali

Amri

Poutaletsje

Modagam

Taccada

Bella ?

Ramena Pua or
Pou Maram?

Celtis Acata
Zizyphus Mauri tiana
Melastoma aspera

„ Malabathrica ?
Avicennia Oepata
Guettarda ?

Samyda Canziala

„ piscicida

„ glabra

?

Sapium Indicum
Melia integerrima
Camunium Bengeleuse
Bergera integerrima
Olea dioica

Agyneja multilocularis
Physalis Sugunda
Antidesma Zeylanica

„ paniculata

Callicarpa ?

Azalea ?

Scaevola taccada

,, lobelia }

„ Modagam \
Sterculia guttata
„ Balanghas

According to Hamilton, the Valeria Indica produces the gum
anime which Dr. Roxburgh says is termed in commerce. East
Indian Copal. Schindler tells us that there are three kinds of Copal :

1. The East Indian, or African Copal, is the brightest and softest,
and affords the best varnish. It is sometimes called ball copal.

2. The second variety is called West Indian or American Copal,
being derived from the Antilles, Mexico, and North America, and is
procured, according to Martins and Hayne, from different species of
Hymenea, Track ylobium, and Vouapa. It is termed stone copal,
and is yellower than the preceding kind. It comes to us in hard,
flat pieces, weighing about three ounces. It is less easily melted than
the preceding variety, and seldom contains insects. 3. The third
variety is also termed West Indian copal, but might be mistaken for
the lirst species, as it occurs in the form of convexo-concave pieces,
eight ounces in weight. Taste aromatic. Melting point between
that of the two preceding. Fresh oil of rosemary dissolves the first
in any proportion. Fresh oil of turpentine dissolves the first variety
completely, but only dissolves a small portion of the other two, after
long digestion. The action of alcohol is similar. Schindler terms
the last species, for the sake of distinction, insect copal.

These facts I consider it proper to bring forward, because Dr. Ha-
milton denies that copal comes from India. Now, this opinion is at
variance with the statement of Retzius, who called it Etaeocarpus

* Pharm. Centralblatt and Erdm^n und Schweigger — Seidel's Journ. iv. 149.

1835.] Transactions of the Luinean Society of London. 307

copalliferusy because it afforded the gum copal. Dr. Roxburgh alleges
also that the resin of the Paenoe is called East India copal. Mr.
Turnbull of Mirzapour informed Dr. Hamilton that some which he
sent home for trial would not sell for copal, although it was allowed
to be anime, /* The real copal and anime," he adds, " are American
productions." The resin of the Paenoe, or Dupa (Vatena Indica)
was probably used by the Brahmans of Malabar as an incense. The
Paenoe is one of the finest ornamental trees in India ; and in the
province of Canara it is usually planted in rows by the sides of
highways, making remarkably fine avenues. The statement of Mr.
Turnbull is not conclusive, because he does not state that its rejection
was the consequence of chemical examination.

The paper of Dr. Daubeny, who is professor of both the very
extensive sciences of chemistry and botany, is devoted to an account
of some researches carried on in prosecution of the curious facts
pointed out by Schrader and others, who found that there was some
reason to conclude that plants, in their assimilating processes, pro-
duced silica.

Their method of proceeding was first to burn the seeds and ascer-
tain the quantity and nature of the residual earthy matter ; then to
sow a given portion of similar seeds in sulphur : and then to ascertain
the nature of the earths contained in the ashes of the plant. Dr.
Daubeny employed different soils, and instituted a comparison be-
tween the effects of each. The materials of the soils were sulphate
of strontian, Carara marble, sea sand, and mould. The results do not
appear to lead to any new inference. The author, however, con-
cludes '' that the roots of plants do, to a certain extent at least, pos-
sess a power of selection, and that the earthy constituents which form
the basis of their solid parts, are determined as to quality by some
primary law of nature, although their amount may depend upon the
more or less abundant supply of the principles presented to them
from without."

The order Hydrophylleae was first pointed out by Mr. Brown,
in his Prodromus Flor. Nov. Holl. under which he included the
genera Hydrophyllum, Phacelia et Elluia, and afterwards added
Nemophila and Eutoca. Mr. Bentham, in the present paper, describes
forty species belonging to these five genera, and a new one which he
terms Emmenanthe, They all differ from their nearest allies, the
Borragineae, in the capsular point, and copious albumen, and the
structure of the ovaium. In the Hydrophyllum^ Nemophila, and
Ellisia, the placentae are broad, fleshy, line the whole ovarium, ad-
here at the top and basis only, being free from the parietes, and bear
on their inner surface, each of them, from two to sixteen ovulae,
placed in two vertical rows, one on each side of the central line.

In Eutoca, Phacelia and Emmenanthe the placentae are linear,
or slightly dilated, and adhere more or less to the parietes along, their
central line, bearing on their inner surface from two to fifty or sixty
ovulae.

x2

308 Analyses of Books. , [Oct.

I. Htidrophifllum comprehends the species, 1. Appendiculatum,
from tlie Alleghanies ; 2. Canadense ; 3. Virginicum ; 4. Macro-
phffUum, near the Columbia.

IT. Ellisia. 1. Ntjctelea, Potowmac and Missouri ; 2. Ambigua,
Missouri ; 3. Membranacea California ; 4. Crtjs ant hemif alia
California ; 5. Microcalyx ; 6. Ranunculacca.

III. Nemophila. 1. Paviflora Columbia ; 2. Pedunculata
Columbia; 3. Pkaceloides ; 4. ^wri to California; 5. Insignis
California; 6. Menziezii.

IV. Eutoca. 1. Douglasii California; 2. Cumingii Chili;
3. Brachyloba Califorma; 4. Mexicana; 5. Parvijlora Fensjl-
vania; 6. Loasatfolia California; 7- Franklinii ; 8. Menziezii
California; 9. Sericea ; 10. Grandijlora California; 11. Divari-
cala California ; 12. Phaceloides California.

V. Phacelia. 1. Malvaefolia California ; 2. Brachyantia Chili ;
3. Circinata Columbia ; 4. Integrifolia Platte ; 5. Ciliata Cali-
fornia; Q. Ramosissima California; ^, TanacetifoliaCAiioxmo.;
8. BipinnitiJidaA]leghainies; 9. Fimbriata Kentucky; 10. Hir-
suta; 11. Glabra.

VI. Emmenanthe Pendulijlora California.

Of these species 19 were sent from the western parts of North
America, by the indefatigable Mr. Douglas, who, unfortunately, lost
his life in the Sandwich Islands, during the prosecution of his bota-
nical researches.

The chief interest of the genus Diopsis arises from the extraordi-
nary elongation of the sides of the head into two cylindrical horns,
which, in some instances, are as long as the whole body, and at the
extremity of which, the eyes, of a semi-globular form, are placed.
The antennae, also, are inserted near the extremity of these protu-
berances, at a short distance before the eyes. These horns, at first
sight, might be mistaken for antennae, but they are inarticulated at
the base, as well as along the surface ; they have, therefore, no inde-
pendent motion, their movements being, necessarily, accompanied by
those of the whole head. When, however, we recollect that they
contain not only the infinity of nerves of the compound eyes at their
extremities, but also those producing the sensation, of which the an-
tennae are the seat, we can easily imagine how necessary it is that
the means of communication with the remainder of the head should
be unbroken by articulation. Mr. Westwood describes 21 species:
1 . Ichneumonea Guinea. 2. Collaris Senegal. 3. Pallida. 4.
Nis:ra Sierra Leone. 5. ApicaliH Sierra Leone. 6. Tenvipes
Senegal. 7* Indica Bengal. 8. Afisimilis. 9. Abdominalis.
10. Furmpennis. Senegal. I \. Pur. ctiger Went Africa. 12. Sig-
nata Sierra Leone. 13. Fascia fa. 14. Concolor- West Africa.
]/). Macrophfhalma Sierra Leone. 16. Thoracica West Africa.
17. Ohftcnra Sierra Leone. 18. Confusa Congo, Sumatra. 19.
Dalmanni Java. 20. Sykesii East Indies. 21. Brevicornis
Pennsylvania.

This paper is illustrated by engravings of twenty figures.

1835.] Scientific Intellicjcnce. 309

Article IX.

SCIENTIFIC INTELLIGENCE.

I. — British Association. — Continued from page 224,
Anatomy and Medicine.

Monday, August \Oth. — Dr Graves read a paper on the employ-
ment of chloride of soda* in fever. This preparation was first em-
ployed internally in 1827, by Dr. Read. The author began to use
it in 1832, and has found it a powerful remedy. It is most advise-
able in collapse following re-action, to the extent of 15 or 20 drops
of the saturated solution in an ounce of camphor mixture, and re-
peated every 4th hour. Its use is to be avoided in re-action, and
when any symptom of local inflammation is present. The beneficial
effects are evident in its warding off inflammation of the tympanum,
restoring the secretions, especially of the skin, mucous membranes
and liver. A letter was read from Dr. Stokes, in which this remedial
agent was highly approved of.

2. Dr. Houston explained the provisions in the structure of diving
animals, by which they are enabled to undergo emersion in water.
He argued that no state in which animals can be placed is so inju-
rious as that where respiration is suspended, and that whales which
can remain 20 minutes under water, as well as all diving animals,
have a temporary provision established by means of the great size
and complexity of the veinous system, especially in the right cavi-
ties of the heart, venae cavae, hepatic veins, and those of the abdomen
and spinal canal. The observations were illustrated by preparations.

Tuesday^ August \\th. — Mv. Harrison read the report of the
Dublin Committee on the motions and sounds of the heart. It con-
sisted of three divisions. The first detailed a number of experiments,
which were made for the purpose of elucidating the motions of the
heart. The second part was devoted to the results of an experimen-
tal inquiry into the causes of the sounds of the heart ; and the third
consisted of inferences deduced during the examination of the various
phenomena. The experiments were instituted on calves. On re-
moving the sternum the heart was observed to beat with a vibratory
motion on longitudinal axis, 80 pulsations in a minute, the apex of
ventricles becoming elevated on their contraction ; the auricles swelled
up, then subsided, and the ventricles contracted. The prolonged
and dull sound of the heart began and terminated with the contrac-
tion of the ventricles, and was instantly succeeded by the second sound
sharp and quick. When the heart was laid on a table the first sound
was distinct, the second absent. When the semilunar valves were
confined in close apposition with the walls of the vessels, the second
sound was lost. The first sound, it was concluded, arose from the
flow of the blood over the rough surfaces of the sides of the ventricles,
increased by the muscular contraction. The second sound was attri-
buted to the elasticity of the coats of the arteries, in connexion with
the heart, and depends upon the semilunar valves.

* From the experiments of JJalard we may infer, that this compound consists of
chlorite of soda, and chloride of sodium. — Edit.

310 Scientific Intelligence. [Oct.

Dr. Williams gave an account of similar experiments. His deduc-
tions were coincident.

Wednesdaij, 12//i August. — 4. Dr. ]Mc.Donnell read a paper on
the pulse and breathing. He affirmed, that the number of pulsations
varies with the posture. This he terms the differential pulse.
When it is absent, it may be concluded that diseased action is present.
The pulse of the foetus is very slow, and is doubled at birth. He
concludes, that as little inconvenience is experienced by considerable
fluctuations in the quantity of carbonic acid exhaled from the lungs
that the decarbonization of the blood is the least important part of
respiration.

5. Dr. Harrison read a paper on '* Bones in the heart of Rumi-
nantia." He exhibited specimens of bones obtained from the heart
of the common ox, and shewed that they were not accidental ossifica-
tions, but are constantly present. They exist also in the calf. They
have not been detected either in the horse or the stag. Their prin-
cipal uses appear to be to preserve the patency of the aorta, to serve
as a fixed point of action to the muscular fibres, to prevent the ven-
tricles from being totally closed, and to protect the large sinuses from
the powerful resiliance of the aorta.

6. Mr. Houston described the habits of the Cistocircus tenui-
cotlis, a hydatid found in living animals, but especially in the omen-
tum of the deer. They are enclosed in cysts to which they do not
adhere. The specimen exhibited, possessed a head with a long nar-
row neck and caudal vesicle. The author considers that the opinion
which asserts that the antazoa are the consequence of disease is un-
supported by any facts.

Dr. Harrison stated that he had found these animals pervading
the muscles of voluntary motion, each animalcula being coiled upon
itself in about two whorls, and enveloped in a white capsule. A spe-
cimen of the biceps muscle was exhibited which was completely studded
with them. Muscles in which these exist are invariably wasted.

7. Dr. Jacob read a paper on the mammary glands in cetacese, in
which he controverted the opinions of St. Hilaire, and proved that the
process of suction can be performed under water. Hence, it is un-
necessary to suppose that the subcuticular muscle assists by pressing
on the gland.

8. Dr. Collins read a report of the Lying-in-Hospital.

9. Sir James Murray read a paper on atmospheric pressure as a
remedial agent.

Thursday I3lh. — 10. A report was read from Dr. Roupell on
■the effects of poisons upon the stomach.

1 1. Dr. Alison read a paper on the state of the arteries in inflam-
mation. He deduced from his experiments that the arteries in the
seat of inflammation are weakened and dilated, while those in the
immediate neighbourhood are in a state of increased action.

12. Mr. Walton described an operation practised by him for the
cure of caries in the bones of the foot — consisting in a removal of
the lateral half of the foot.

13. Dr. Stokes read a paper on the diagnosis between accumula-
tions in the chest of fluids and of air, in which he pointed out a new
ground of distinction arising from paralysis of the respiratory mus-
cles, in consequence of the inflammation existing near them.

1835.] Scientific Intelligence. 311

14. Dr. Kennedy on purulent opthalmia.

15. Dr. Perry on the analogy between typhus ever and scarlatina.

16. Mr. L'Estrange exhibited an improvement on the calculo-
fractor for lithotrity.

17. Dr. Corrigan read a paper on the nature of the bellows sound
of the heart and arteries — he attributes its production to the changes
occasioned by disease, on the velocity and mode in which the blood
flows through the vessels.

Friday l4. — 18. Dr. O'Beirne on his views of the functions of
the bowels.

19. Dr. Osborne made some observations on the effect of cold on
the human body, contending that this influence has been too muck
overlooked. He described an instrument by which the relative tem-
peratures of air and water in different states of motion and rest may
be tested, and their effects shewn in such states upon human health.

20. Mr. Hutton described a case of disease of the brain attended
with idiocy and congenital dislocation of the hip joint.

21. Mr. Adams on aneurism by anastomosis.

22. Mr. Snow Harris exhibited the bones of the hip joint of the
celebrated commedian, Charles Matthews, who was supposed to have
sustained a fracture of the neck of the thigh bone by a fall from a
gig many years ago ; he walked after the accident, but subsequently
after long confinement in bed, the limb became shortened. Con-
siderable difference of opinion existed with regard to the nature of
the disease, but it appeared to be most generally admitted that it
was disease of the joint. A committee was appointed to examine
into the nature of the case.

23. Dr. Handyside gave an abstract of experiments made to de-
termine the respective powers of the lymphatics, lacteals and veins
in carrying on absorption from the integral surfaces of the body.

Botany and Zoolos^y, — Monday, \Olh August. — Mr. Niven
explained a natural arrangement of plants. Mr. Ball exhibited
specimens of the Penticranus Europaeus and Beroe ovatus, Mr.
Babington stated that he had found a new species of Scirpus abun-
dantly near Holyhead. This plant Dr. Graham mentioned he had
found in Galloway. Dr. Graham found also the Orchis Pyramidalis
in Galloway ; and Dr. Knapp observed it in Fife. Mr. Babington
stated that in general three species of Ranunculus, viz., aquatilis,
palustris, and circinatus, were confounded with aquatitis; and that
Reichenbach made three species out of Orchis bifolia, two of which
were natives of Great Britain, and were distinguished by the form
of the anthers, the one being round, the other longitudinal.

Dr. Drummond observed that the common Gordias was vivipa-
rous ; when placed in water with a common newt, it twined itself
round the animal and killed it.

A letter from Mr. Hamilton of Mexico was read, describing some
new plants.

Dr. Coulter mentioned that he had seen a species of Veratrum,
not the sabadilla, called by the natives the Indian's root, prove suc-
cessful in dyspepsia.

Tuesday, IMh. — Mr. Mackay exhibited several specimens of bog
timber, consisting of Scotch fir, which was found eighteen feet under

312 Scientific Intelligence. [Oct.

the surface, and some portions which seemed to have been charred
when they fell.

Dr. Jacob read a paper on the infra-orbital cavities existing in the
deer and antelope.

Wednesdaifj \2th, — Mr. Nicol read a communication on the
structure of the horizon al branches of the coniferae.

Dr. Neil described some facts in relation to a landrail in Orkney,
which appear to favour the idea of hybernation ; when exposed to
the heat of a fire it was restored, but soon afterwards died.

Dr. Daubeny made some observations on the exhalation of mois-
ture from the leaves of plants ; on the combined influence of heat
and light ; and on the effect of heat without light.

Mr. Marshal read a communication on the Zoology of Rathlin.

Professor AUman described a natural arrangements of plants.

Thursdat/, \3th. — Mr Sturge detailed the discovery of a toad
in a fragment of sandstone at Park-gardens, Coventry, (see Records,
vol. ii. p. 235.) Mr. Mackay stated that the toad existed at Killar-
ney, in the county of Kerry.

Dr. Barry gave an account of some observations on the apparent
colours of the sky.

Mr. Mackay noticed the great age of the yew, and produced a
section, which proved that the tree from whence it was taken was
above five hundred years old. The variety called Flourincourt, he
stated, is a native of Ireland. He read a list of plants peculiar to
Ireland, amounting to about thirty in number.

A method was mentioned by a member, of preserving the spines of
the echinus, viz., by immersion in a solution of muriate of lime.

Statistics. — Monday, lOth Aus;ust. — Dr. Maunsell read a paper
on the Foundling Hospital of Dublin. The number of children
received between 1798 and 1831 was 51,523; of these 700 were
immediately restored to their parents, and 12,153 died on being
taken into the nursery, whose deaths must be attributed to expo-
sure; of the remaining 38,670, there died before reaching their
ninth year 16,976, but 8,278 were lost sight of between their 1st
and 14th year ; 1050 were retained from affection by their nurses.
The total number alive at the 9th year was 12,832. In 1822 the
restrictions placed on the admission of foundlings were very favoura-
^ ble to life ; of 2,339, 14 were claimed by their parents, and 131
retained from affection by their nurses; the deaths were 1030, and
the survivors at the 9th year 1295.

Tuesday, Mth. — Mr. Langton read a report on the state of
education at Manchester. The number of scholars in that borough
is 43,304: of whom 10,108 attend day and evening schools only ;
10,011 attend both day and Sunday schools; 23,185 attend Sunday
schools only. The population of the town is above 200,000 : hence
the number receiving instruction is 21*65 per cent., and of those
attending day and evening schools about 10 per cent. The whole
number of children between 5 and 15 years is 55,000 (5 of the
whole population). Now, 43,000 are receiving instruction, but
10,000 of these may be above 15 and below 5 ; therefore there are
only 33,000 out of 50,000 receiving instruction. He stated that
the parliamentary returns were very inaccurate, and he gave a most

1 835 .] Scientific InteUUjence . -3 1 -3

melancholy picture of the state of the schools in the town, especially
of the ignorance of the teachers.

The Rev. Mr. Stanley stated that he had lately made a tour in the
west of Ireland, and had found the quantity and quality of instruc-
tion, above the common average of England. He could not forbear
mentioning that he had been much pleased with the sound and scrip-
tural answers received from the boys, in a school exclusively Catholic.

]Mr. Gregg read a report on the social statistics of the Netherlands.

Dr. Cleland's paper on the Glasgow Bridewell was then read.
During the year there have been (exclusive of 356 that remained
2d August, 1833) 1967 persons committed, and 2030 liberated,
leaving 293 confined on Id August, 1834. Besides £ 116 5s. 3d.
paid to inmates, the produce of the work performed during the year
maintained all the prisoners, with a surplus of 401/. 14s. lid.,
which goes to lessen the expenses of wages, &c. A deficiency of
590/. \0s, divided by 1697, shews that the net expense to the public
for every committal is 6.9., the average period of residence being
59i days. The prisoners work twelve hours daily ; one-half sleep
in hammocks in their cells ; the other half have separate sleeping
places. Dr. Cleland is of opinion that solitary confinement is much
superior to a silent system.

Wednesday^ 12^/^.— Colonel Sykes read a paper on the compara-
tive state of the Deccan under the Peishwa and the company, shew-
ing that under the latter, the condition of the people had been much
ameliorated.

Dr. Maunsell read a paper on the Dublin Foundling Hospital.

Mr. Babbage read a communication on the effect of co-operative
shops. The workmen of Mr. Strutt of Derby, formed a joint-stock
shop for the sale of necessaries among themselves, and continued the
practice from 1818 to 1832, when it failed. The sale was greatest
during the fourth year, and the profit greatest at first. The cause
of failure was attributed to ignorance of mercantile affairs, and bribery
on the part of the wholesale dealers.

Thursday^ \'dth. — Colonel Sykes read a paper on the state of
education in the Deccan, from which it appeared that the Hindoos
were more anxious to profit by European instruction than the
Mahometans.

The Rev. Mr. Stanley read a paper on the religious attendance
and state of education in his own parish, that of Alderly in Cheshire.
He stated that J^^ of the whole population attend Sunday schools,
^ day schools, i morning, -^ evening service, and J- communicate.
There are no dissenters in the parish.

Dr. Reid detailed a plan for the early instruction of children in
physics.

Friday^ I4th. — Mr. Babbage read an abstract of the ordnance
survey of the parish of Templemore and city of Londonderry. He
considered it a perfect model for a statistical report.

Dr. Jones read a paper on the condition of the Irish Lunatic
Asylum.

Mr. Fox read a paper on the punishment of death in Norway and
Belgium, from which it was inferred that violent crimes diminish in
proportion to the rarity of executions.

314 Scientific Intelligence. [Oct,

II. — Anatase, Naphthaline, Bi-Calcareo Carbonate of
Barytes, Chemical Symbols.

The following' remarks are from a very intelligent correspondent
Bath, dated September 19th : —

" Sir, — Permit me to thank you for having presented the scientific
public with the Records of General Science. I am glad so much
attention is paid in the work to the progress of chemistry and mine-
ralogy, sciences which, in my humble opinion, have been much ne-
glected in the other periodicals. As a very humble labourer in the
field, I have to communicate a little information on one or two
points, of which you are at liberty to make what use you please.

1. The accompanying specimen (of which I beg your acceptance)
was sold to me some years ago, by Mr. Kennard, the mineral dealer,
who called it anatase, and said that its locality was the neighbourhood
of Dartmoor. Some time afterwards a friend brought me another spe-
cimen, labelled Titanium, Virtuous Lady, Tavistock. Its external^
characters correspond with those of anatase, as mentioned by Phillips
in his mineralogy, 3rd edition, 1823. He mentions that ^' the Comte
de Bourn on cites a crystal on granite from Cornwall, as being in his
own collection." The matrix of the present specimen is chlorite,
and in another specimen it is accompanied by spathose iron and cop-
per pyrites. If it be anatase, it is well worth while to notice it as
a new and English locality of that rare mineral.

2. I have also sent a mass presented to me by Mr. Lake, the intel-
ligent superintendant of our Coal Gas Works, and which proves that
napthaline is the product, sometimes of a Coal Gas work, as well as
of an Oil Gas one. (Mr. Connell has mentioned an instance of the
latter in No. 26 of Jameson's Philosophical Journal). It was found
in the principal main to a distance of between two and three hun-
dred yards from the station On exposing it to a slight heat, the
crystals of naphthaline are sublimed, and may be collected in a glass
bell, beautifully white. My attention was first attracted to the
matter by observing the wires which had been introduced into the
main to remove the obstructions existing in them, covered with a
white shining substance resembling flakes of spermaceti, and soiled
with a brown fluid, containing (I suppose) some of the substances
described by Runge in your first number. There was a considerable
quantity of it in the main, and much trouble was occasioned in get-
ting rid of it, as boiling water would scarcely touch it.

3. I would put the following query. Is not the new form of
baryto-calcite described by Mr. Johnston in the January number of
the Philosophical Magazine for this year, identical with the bical-
careo-carbonate of barytes of Dr. T. Thomson ? I have a specimen
of the latter, and am in hopes of obtaining one of the former. The
external form appears to me to be the same, and it is possible Mr.
J. may have made a mistake in the exact determination of the con-
stituents. As the dimorphism of baryto-calcite rests upon the de-
termination of this point, I thought it not amiss to throw it out for
consideration."

Note. — 1. I have examined the mineral specimen which ray corre-
pondent has been so very obliging as to send me, and find it to possess
all the characters of anatase.

1835.] Scientific Intelligcitce. 315

2. The occurrence of napthaline in a coal gas work is not new^ as
it was first obtained from that source.

3. The suggestion of my correspondent in reference to the iden-
tity of bicalcareo carbonate of barytes, and the new form of baryto-
calcite described by Mr. Johnston, I consider to be quite correct. A
similar remark was made to me immediately after the publication of
the paper in the " Records." I am glad to have an opportunity of
noticing the circumstance, because I observe that Mr. Johnston's
paper, in which he draws inferences in support of a peculiar theory,
has been translated into the German journals. An opportunity is
thus suggested to him of repeating his analysis, and corroborating
his first result, or correcting his error.

I may take this opportunity of remarking upon the observations of
another correspondent who has been so good as to favour me with
some useful hints, that the object in employing italics to represent
the oxides of iron in the cases referred to, was merely to draw a dis-
tinction between that base when united with acids and when united
with sulphur. Again, when only one compound of a base and
oxygen is found in the mineral kingdom, it seems unnecessary to
characterize it, as far as mineralogy is concerned, further than as being
in union with oxygen. ,

The propriety of adopting Berzelius's symbols, by which I under-
stand the points for oxygen, the commas for sulphur, &c. appears at
present problematical, as they open the way for a kind of practical
alchemy, are only used by his own pupils, and a few others, and will
be of no service except in inorganic chemistry. Is not SO^ for sul-
phuric acid, and Fe S for sulphuret of iron much more intelligible,

and less liable to be mistaken by the printer or reader than S or Fe.
This plan of attaching a new signification to the instruments of
punctuation may lead, and has led to great abuses, while the mere
employment of initial letters and figures is not likely to do so. I
should be glad to hear the arguments of those who are interested in
the question, in reference to these two kind of symbols. It is only
by a public discussion that any chance of settling the point can be
anticipated. Let this be done concisely, and it will be readily dis-
covered upon which side the strength of argument lies; we shall then
be able to present our readers with a useful set of tables.

III. — Blue Velvet Copper.
( To the Editor of the Records of General Science.

Sir, — Kupfersamniterz, the blue velvet copper, is quoted by Mr.
Allan (Manual, p. 84) as " principally from Moldawa on the Ban-
nat." " From its extreme rarity, the characters of the species have
not yet been accurately ascertained." When this shall have been
done, it will probably be found not entitled to rank as a distinct spe-
cies. It is occasionally raised in Cornwall, and one or more Cornish
specimens is placed in every respectable collection in that county,
amongst the arseniates of copper, though it may not, perhaps, have
been correctly analyzed. But in the Scorrier collection is a good suite of
this species, appearing to connect it with Strahlertz, the oblique pris-
matic arseniate. The suite runs from a fine smalt-blue velvety tu-

316 Scientific Intelligence. [Oct.

bercular coating, up to crystals, 0,25 in length, and 0,01 diameter,
with distinct brilliant faces, and a rich Berlin blue colour. The
connecting specimens of Strahlertz are in fibrous radiating tubercles,
the fibres not much inferior in dimensions to the last-mentioned ; of
similar hue within, and almost black on the convex tubercular sur-
face : the series passing on from this gradually through the other
varieties of Strahlertz. If the measurements shall be found to agree
with those of Strahlertz, it would be enough to settle the question,
without sacrificing any of this rare substance for analysis. P.

IV. — Para-morphine and Pseudo-morphine.

These two substances were obtained by Pelletier in treating opium
with lime and ammonia. The first is white, soluble with difficulty
in water, very soluble in ether and alcohol, even without heat, pos-
sessing an acrid and styptic taste. By evaporation it crystallizes in
needles ; weak acids dissolve it ; alkalies precipitate it from its solu-
tions. An excess of alkali does not re-dissolve the precipitate ; its
solution in acids never affords crystals ; yellow plates are procured on
evaporation. It freezes at ISO^ (302oF.) and does not volatilize at
a higher temperature, but decomposes, giving out azotic products.
It differs from morphine, in not reddening concentrated nitric acid,
in not forming crystallizable salts with the acids, and in not pro-
ducing a blue colour with the salts of iron. It approaches codeine
in its solubility in alcohol and ether, and by its alkaline nature, but
it differs in not crystallizing in large crystals, in not forming crys-
tallizable salts, and in being always precipitated from its acid solu-
tions by ammonia. It has no analogy with meconine and narceine.
It resembles in some degree narcotine, but the taste, fusibility, and
solubility in alcohol are sufficient to distinguish them.

Pseudo-morphine is almost insoluble in water, alcohol,*? and
ether, yet alcohol of sp. gr. '837 dissolves a little of it ; potash and
soda dissolve it in great quantity. By saturating the alkalies with
an acid, the matter precipitates. Concentrated sulphuric acid ren-
ders it brown, and decomposes it. Concentrated nitric acid acts upon
it as upon morphine, converting it into oxalic acid. A very intense
blue colour is produced when it is brought in contact with the salts
of iron, especially the muriated peroxide, which disappears with an
excess of acid. The same salt dissolves it in considerabble quantity,
forming a fine blue solution, which becomes green by the application
of heat ; ammonia produces a slight precipitation in this solution,
and gives it a red colour. When heated in the fire it softens and
decomposes. Distilled in a retort it gives oil and acidulous water,
from which potash disengages ammonia, and leaves charcoal. The
constituents of the two substances compared with morphine are,

Para-morphine. Pseudo-morphine Morphine.

Carbon .... 71-310

Oxygen .... 17992

Hydrogen . . . 6-290

Azote .... 4.408

(Journ. de Chim. Medic. I 449. 2nd Scries.)

52-74

72-340

3737 ■

16 299

5-81

6-366

4-08

4-995

183.5.] Scientific Intelligence. 317

V. — Massy Iridium, by Gustav Rose.
In the ix. vol. s. 1. and s. 96, of Schweigger's Jahrbuch fur
Chcmie and Phijsik, Breithaupt describes grains which were dis-
tinguished in the Uralian Platinum, and possess the highest specific
gravity of any known substance.

The grains are round and full of small cavities, and sometimes
assume the appearance of crystallization. Breithaupt considers them
fragments of octahedrons. Their cleavages are in three directions.

The grains possess a strong metallic lustre ; externally their colour
is silvery white, which passes into yellow ; internally they are silver
white, passing into platinum gray.

Their hardness is between that of felspar and glassy. They po-
lish the best file, and are consequently harder than all known metals
and metallic compounds. They are but slightly ductile. The
specific gravity of several grains which weighed together 01035
drachms, Breithaupt found to be 23*646. The density of two single
grains which weighed 0*03875 and 0-0404 drachms (about 0-14
and 0*136 grms or 2*167 and 2*098 E. grains,) he found to be
21-527 and 22*494.

Breithaupt and Lampadius found by examination that these grains
consisted of iridium, with very little osmium, from which circum-
stance the new mineral was termed massy iridium.

Last summer Professor Schiiler came from Freiberg to Berlin,
and brought with him a grain which Breithaupt stated to agree with
those described. Schiiler allowed Gustav Rose to take the specific
gravity. He found it 21*85, the temperature of the water being
12' R. (590 Y.); its absolute weight was 0284 grms. (4.082 grs.)
It resembled in appearance another grain which Rose had found
among a portion of osmium-iridium from Newiansk in Ural. He
took the specific gravity of this also. Its absolute weight was 0*2622
grms; its specific gravity 22-800 at 59'' F.

The grain was originally larger, but Rose had broken oflP a portion
to ascertain whether it possessed the cleavage of osmium-iridium, for
which mineral he had mistaken it previous to the arrival of Professor
Schiiler.

The fragment when examined before the blowpipe, as with the
common osmium-iridium, yielded no smell of osmium and underwent
no change.

These grains agreed in colour with a crystal which Rose brought
from Nischne Tagilsk, resembling what he had described as lead-
gray plates of osmium-indium. It was a combination of the
hexahedron with the octahedron, the faces of the latter predomi-
nating ; the faces of the hexahedron were about one line broad.
Rose did not examine it further until Breithaupt, when at Berlin,
saw it, and from its white colour suggested that it might be the same
as his massy iridium. The determination of its specific gravity con-
firmed this suspicion. Its density was 22*65 at 53|o ; its absolute
weight -188 grms (2*9 grs.)

Rose sent a portion to Berzelius for analysis. It was examined

318 Scientific Intelligence. [Oct.

by Lieutenant Svanberg, a pupil of the Swedish chemist. No osmium
was detected, but it contained : —

Iridium, 76*85
Platinum, 19-64
PaUadium 089
Copper, 1*78 besides a trace of a substance

supposed to be titanium.

99-16 (Pog^. Ann. xxxiv. 377.)

VI. — Remarkable Flight of a Bird.

Madox, in his Excursions in the Holy Land, mentions that, in
the course of June 1825, a hawk was killed at Damascus, with a piece
of wood attached to its neck, upon which were the words Lands-
berg in Preussen, 1822. The interest of the fact induced Professor
Ehrenberg to insert a notice of it in PoggendoriF's Ann. xxxi.
576. It attracted attention, and by the exertion of his Excellency
President Hr. Schbn, two documents were forwarded to Professor
Ehrenberg, which establish the fact of the flight of the bird from
Landsberg. The first is from Hr. Kob, a clergyman of Landsberg,
the second from an old beadle in the town, Deukel, by name. From
these it appears that Counsellor Ribbentrop (since dead) formerly a
neighbour of Hr. Kob, placed in his garden, in the year 1822, a golden
eagle and two goshawks, which had been caught young. Labels,
bearing the words above mentioned, were attached to their necks.
They were allowed to go at liberty, and were fed daily by Dunkel.
After they grew up, they successively took flight, about 1823 and
1824. These documents are now in the possession of Professor
Ehrenb e. (Pogg. Ann, xxxiv. 183.)

VII. — Black Mud from Common Sewers.

At the time when cholera was prevalent in the south of France, it
was deemed expedient to cleanse the common sewers of the town of
Nancy. Braconnot took advantage of the opportunity to examine
the mud derived from them. With dilute muriatic acid, a lively
effervescence was produced, and carbonic acid and sulphuretted hydro-
gen were disengaged. The supernatant liquor contained iron and
lime in solution. Hence, the colouring matter of the mud appears
to have been sulphuret of iron, the composition of which seems pro-
portional to the peroxide of the metal. The sulphuret of iron, which
forms the colouring matter, is obviously derived from the contact of
sulphuretted hydrogen, produced by the decomposition of organic
substances, with the peroxide of iron contained in the earth ; most
substances, it should be observed, which were extracted from the
sewer, such as bones, wood, calcareous stones, were penetrated by the
sulphuret of iron, which gave them a deep black colour. No crys-
tallized pyrites was, however, observed. He conceives that the wood
found in marshes, ditches, &c., possessing a dark colour, owes this
tinge to the action of sulphuret of iron.

The mud of sewers, when boiled with water, scarcely colours it ;
and, by the evaporation of the filtered liquid, a small quantity of
animal matter remains, which is yellow, inodorous, easily soluble
in a little cold water, from which it is precipitated white, by the in-
fusion of nut-galls, and by nitrate of silvej ; and, after combustion,
affords some traces of muriate of soda.

1835.]

Scientific Intelligence.

319

The thin portion of the mud afforded no ammonia Ly caustic
potash. The filtered liquid was brown. A drop of it placed on
silver produced a black mark of sulphuret of silver. An acid
dropped into this liquid occasioned the disengagement of sulphur-
retted hydrogen, and a yellow fl.ocky precipitation of animal matter.
When well washed it acted on turnsol paper, and saturated alkalies.

Caustic ammonia takes up a brown matter, soluble in cold water,
and reddening turnsol. The] same substance, precipitated from its
alkaline solution by an acid, is scarcely soluble in cold water, although
it communicates to it a brownish colour.

By distillation much empyreumatic oil is obtained, as well as am-
monia and sulphur, while charcoal remains, which, after combustion,
leaves a quantity of oxide of iron. — Ann, de Chim. 1. 213.

Ylll.— Gums.

Herberger has obtained different results from Guerin. He finds that

1. Gum arable is not quite identical with gum Senegal, neither
with regard to its chemical or physical properties. »

2. Gum Senegal differs from gum arable in its external appear-
ance, in having a higher sp. gr. Gum Senegal forms, with water, a
jelly, more sensible to the salts of oxide of iron than gum arable.

200 grs. of each of these gums were exposed to a temperature of
34o R. (108 J F.) until they ceased to lose weight.
Gum arable lost in half an Gum Senegal lost in half an

hour - - - 11 grs. hour - - - 11 grs.

The second half hour 2 5

The third - - 2 4

The fourth - - 2 ... 1

17 21

100 grs. exposed to a temperature of -\- 80 R. lost — Gum arable
17i; gum Senegal 19| ; but underwent a slight decomposition.
The specific gravity in three experiments was —

Gum arable. Gum Senegal.

1st. 1-5256 1-6510

2d. 1-4606 1-6511

3d. 1-5103 1-5686

Solubility. It is difficult to determine this point. Herberger
fixes upon that state in which it can just be poured in drops.

Gum Arabic. Gum Senegal.

A 4- l2oR(59°F ) equal parts of dried 72 parts dried gum at 34o R in

gum and distilled water.
A -f 80« R (2120F) 108 parts of gum
in 100 parts of watei;.
The capacity of gum arable in enveloping the oils is to that of
gum Senegal as 382 to 964, or as 19 to 32.
Chemical Reaction,

100 parts distilled water.
96 gum in 108 parts water.

R-eagents.

Paper of blue turnsol.
Protonitrate & pernitrate

of mercury.
Subacetate of lead.
Solution of iodine.
Silicate of potash.
Subborate of soda.
Salts of oxide of iron.
(Jourde Pharm. xx.
40

1 ^um arahic in
20 water

Red

Whitish muddiness
White chesey precp.

White flocky precp

Red colour produced
after slight mud-
diness

I 1 part frum Sene-
gal in 20 water.

Red

The same

The same

Immediate pro-
duction of an
ochre jelly

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RECORDS

OF

GENERAL SCIENCE,

NOVEMBER, 1835.

Article I.

Life of the Rev. John Flamsteed, First Astronomer- Roy aL
Written hy himself^

God suffers not man to be idle, although he swim in the
midst of delights ; for when He had placed His own image
(Adam) in a paradise so replenished (of his goodness) with
varieties of all things, conducing as well to his pleasure as
sustenance, that the earth produced of itself things conve-
nient for both, — He yet (to keep him out of idleness) com-
mands him to till, prune, and dress his pleasant verdant
habitation ; and to add (if it might be) some lustre, grace,
or conveniency to that place which, as well as he, derived
its original from his Creator. We may suppose man, in his
innocency, did strictly prosecute the just injunctions of his
Divine Creator ; and Scripture shows us that he did retain
the pleasure of this gorgeous habitation, till, striving to
equal his Creator in knowledge, he lost the pleasure of his
paradise, together with the presential knowledge of his

* This auto-biography is extracted from an unpublished work entitled, " An
Account of the Rev. John Flamsteed, the First Astronomer Royal, compiled from
his own Manuscripts, and other authentic Documents, never before published,
to which is added, his British Catalogue of Stars, corrected and enlarged. By
Francis Baily, Esq." &c., 4to. 1835. " Printed by order of the Lords Commis-
sioners of the Admiralty." The Editor observes that the whole of the text is
printed verbatim and literatim from Flamsteed's Manuscripts, except as to the
orthograpyh.

VOL. II. Y

322 Life of the Rev. John Flamsteed, [Nov.

Creator. Man's active soul had acted now too far to gain
by a recession what his over-active inquisitiveness had in-
duced on him ; for he ejected from his pleasant habitation
his children, made heirs of the fruits of his fall; and the
earth (which formerly produced, of its own accord, sufficient
for human necessity) is cursed for his sake, that he might
earn his bread forth of his labour, and keep himself from
worse employment by his necessary action : for we, who are
Adam's heirs by birth, observe that those are generally
worst employed who have least to do ; and idleness is the
prodrome of other evils.

To keep myself from idleness, and to recreate myself, I
have intended here to give some account of my life, in my
youth, before the actions thereof, and the providences of
God therein, be too far passed out of memory ; and to observe
the accidents of all my years, and inclinations of my mind,
that whosoever may light upon these papers may see I was
not so wholly taken up, either with my father's business or
my mathematics, but that I both admitted and found time
for other as weighty considerations.

I was born at Denby, in Derbyshire, in the year 1646, on
the 19th day of August, at 7^- 16™- after noon. My father,
named Stephen, was the third son of Mr. William Flam-
steed, of Little Hallam ; my mother, Mary, was the daughter
of Mr. John Spateman, of Derby, ironmonger. From these
two I derived my beginning, whose parents were of known
integrity, honesty, and fortune, as they [were] of equal
extraction and ingenuity ; betwixt whom I [was] tenderly
educated (by reason of my natural weakness, which required
more thau an ordinary care) till I was aged three years and
a fortnight ; when my mother departed, leaving my father
a daughter, then not a month old, with me, then weak, to
his fatherly care and provision. She died on September 7,
1649.

It was three years after my own mother's death, that my
father could so well digest as to accept a second marriage ;
which then he did, and married Elizabeth Bates, who, after
she had lived with him an year and ten months, brought
him my sister Katherine : after which, just on that day
two years after my father brought her home, she died,
(November 1, 1654). And now my father had me, my sisters

1835,] First Astronomer-Royal. 323

Elizabeth and Katherine, left to his care and protection,
when I was aged eight years and two months.

My first ten years were spent in such employments as
children use to pass away their time with ; affording little
observable in them. But afterwards my practices began to
show my inclination more plain : for when, by my father's
care, I had gotten at school so much Latin as might make
me understand an elegant English [author], I began to affect
the volubility and ranting stories of romances; and, at
twelve years of age, I first left off the wild ones, and betook
myself to read the better sort of them, which, though they
were not probable, yet carried no seeming impossibility in
the fiction. Afterwards, as my reason increased, I gathered
other real histories ; and by the time I was fifteen years
old, I had read, of the ancients, Plutarch's Lives, Appian's
and Tacitus's Roman Histories, Holingshed's History of
the Kings of England, Davie's Life of Queen Elizabeth,
Sanderson's of King Charles the First, Heyling's Geography,
and many other of the moderns ; besides a company of ro-
mances and other stories, of which I scarce remember a
tenth at present.

But now the providences of God became more observable
upon me, and unto me ; for in the latter end of the year
1660, and the beginning of 1661, it pleased God to inflict a
weakness in my knees and joints upon me. What natural
cause might give it an occasion I know not ; but in [the]
summer preceding, being bathing myself, together with
some boys, my companions, (we might, out of a general
consent, enter those baths which Lord Aston had erected
on the side of the river), whence returning I found no
hurt ; but when I arose the next morning, my body, thighs,
and legs were all so swelled, that they would not admit me
to get my usual clothes upon them ; which swelling (being
laid by rubbing my body and legs with vinegar and clay,
but its original being not evacuated) might, I suppose, fall
into my joints, and thence cause my present impending
weakness. This was, as near as I can remember, the first
beginning of my distemper : what other natural cause God
made use of in inflicting it upon me I am ignorant. In the
year 1662 it increased upon me, and had brought me so weak,

y2

324 Life of the Rev. John Flamsteed, [Nov.

that I was hardly able to go to school. When I left it^ my
master at that time motioned my going to the Universities,
of which my father (fearing, I suppose, my desire of going
thither) told me not till afterwards. Other reasons perhaps
he might have ; as, knowing the negligence of servants,
he might suppose that my presence at home might bridle,
if not remove, those disorders which they were prone unto.
Because I was now of more years and discretion than to be
anywise obliged (either by menaces or intreaties, by care-
lessness or fear) to connive at those faults which my sister,
although discreet, or rather witty, enough for her time, had
not the judgment, care, or knowledge either to discover or
prevent : she hardly then beginning to leave off her chil-
dren's sports and trifles. My natural weakness might be
another moving cause for his retaining me at home : hard
study he perceiving already to distemper my body, argued
that, where my studies would be my constant labour, my
disease would be so much the more violent ; and that if a
day's short reading caused so violent a headache, a week's,
or constant, study would make my disease intolerable. But
I suppose that colds did oftener cause this disease than read-
ing ; and yet, if reading should promote it, yet moderation
and reason might have prevented it : and he is not a man,
or not himself, that cannot use his studies with moderation.
Besides, the Universities might have afforded me so many
advices and helps from the ablest physicians the world
affords, and physic as light [and] cheap, anywhere for my
disease, as no other place could yield me. But since that
God hath otherwise disposed of me, I shall say no more
of it, but only this, — that my desires have been always of
learning and divinity : and though I have been acciden-
tally put from it by God's providence, yet I have always
thought myself more qualified for it than for any other
employment ; because my bodily weakness will not permit
me action, and my mind hath always been fitted for con-
templation of God and his works.

Being thus withdrawn from school, I, within a month or
two after, had Sacrobosco's Spheres, in Latin, lent me, which

• Tuesday before, or Whitsuntide. I cannot well remember whether it was
Tuesday before : Whitsuntide being the I3tli of May, 1662.

1835.] First Astronomer- Royal. 325

I set myself to read without any director in it, but not un-
successfully. For here I laid the ground of my mathemati-
cal knowledge ; and in that winter, before Christmas, my
father taught me my arithmetic, with the doctrine of frac-
tions, and the Golden Rule of Three, direct and converse,
which I learned sufficiently promptly. At Christmas, or a
little after, I went to Uttoxeter, whether my father sent me
for my health's sake, and took with me Fale's Art of Dial-
ling ; and having seen a quadrant formerly, whose fabric,
it was told me, was laid down in that book, I set myself
presently to calculate a table of the sun's altitudes, at all
hours, in the equator, tropic, and some intermediate parallel
in the latitude of 53°, by his tables of natural Sines; which
I did (in Lent that year) without any help, and before that
I heard of any artificial tables ; and accordingly framed
myself a quadrant, of which I was not meanly joyful.

This winter I was weak, and my disease held on with me
till the summer, when it mended a little. This summer,
(1663) I prosecuted my studies; for, returning home, I was
brought into company with Elias Grice, who told me of the
artificial tables, and showed me (as I remember) Wingate's
Canon. I likewise now got Mr. Stirrup's Art of Dialling.,
which I read this summer, and some other authors on ma-
thematical subjects, — as Mr. Gunter's Sector and Canon;
and soon after I acquired Oughtred's Canon of mine own.
In all which I read some parts cursorily, not abiding a
tedious prelection of any throughout, without the help or
directions of any one ; not being permitted (because they
were scarce to be met with) the help of any one so much as
to expound a term unto me.

My studies were discountenanced by my father as much
in the beginning as they have been since ; but my natural
inclination forced me to prosecute them through all im-
pending occurrences. And, indeed, I think this mathe-
matical quality no other than innate unto me ; my father,
in his younger years, having been as much affected with
arithmetic as I at present with geometry and astronomy.

Having gotten the artificial Canon, I calculated several
both general and particular tables, fitting the particular ones
to the latitude of (Derby, my residence) 53° 0', which will
be found amongst my papers. I had some violent pains

326 Life of the Rev, John Flamsteed, [Nov.

and a shortness of breath afflicting me ; which, by God's
mercy, and the means applied by my uncle, John Spateman,
were removed : but my weakness held as ill as at first, and
neither amended nor impaired this year.

I collected a calculative method of dialling from Mr.
Gunter's Sector, and transcribed it (with a method for the
construction of the quadrant, and tables fitted thereto,
calculated by my own hand) in a small paper book ; in
which task, and perusing some other authors of various
subjects, I spent my vacant time this year and the beginning
of the following.

The winter came on and my father thought it fit that I
should undergo a course of physic, to try if thereby my
weakness (which, according to its usual course, began to
increase with the year upon me) might either be diverted or
decreased. But it being thought too far in the year, it was
remitted to the spring (1664); when Mr. Cromwell was
cried up for cures by the Nonconformist party, to whom my
father sent me, to be his patient, under whom I passed a
course of purges and cordials : after all which I found my-
self no better than formerly, and so was by him left off to
the mercy of God. My disease was indeed, inscrutable by
the physicians : its cause (for aught I perceived) being not
understood by any of them. However, I am bound to
acknowledge the mercy of God in that he hath removed
my pains, and left me only under my weakness ; whilst
others, smaller offenders, suffer both weakness, intolerable
pains, and other incommodities all together. And further,
I am bound to bless and praise Him, for that he hath
afforded my father a competent means and fortune to main-
tain me ; whilst to a meaner man I might have been a
burthen — nay (without a mighty providence), an undoing.

This year I also became acquainted with my friends Mr.
George Linacre and William Litchford. I affected the
friendship of the former because of his knowledge of the
fixed stars (few of which were unknown unto him, and by
whom I learned those few I know) ; of the latter, for his
knowledge of the erratic, and judgments on them. Some-
while it was ere that he would admit me that knowledge of
his studies after our first acquaintance ; but that day when
he confessed it unto me, he also told me (amongst several

1835. First Astronomer- Royal. 327

answers he made my inquisitiveness) that he had calculated
(and could promptly do it) the places of the planets to a
given time by the tables in Mr. Gadbury's works. (Horrox's
Tables, published by Mr. Shakerly, but perfected and re-
duced to current account by Mr. Gadbuiy . I was desirous to
essay all sorts of mathematical knowledge ; and therefore
(because I would not be seen with Mr. Gadbury's book, lest
I should be suspected astrological) I bought Mr. Street's
Caroline Tables, intending, when I had time convenient,
not only to learn to calculate the places of planets, but
also to study their motions, and understand their difficult
theory ; but, being someways hindered, T did nothing in it
till the year was over.

I had now completed eighteen years, when the winter
came on, and thrust me again into the chimney ; whence
the heat and the dryness of the preceding summer had happily
once before withdrawn me. But, it not being a fit season
for physic, it was thought fit to let me alone this winter,
and try the skill of another physician on me in the spring.

The year was newly entered, when, on the first day thereof
(viz. the 1st of January, 1665) I, having some vacant time,
set myself to calculate the true places of planets to a given
time, by my formerly mentioned tables : and accordingly
effected it, though not so exactly as by my former calcula-
tions, yet so auspiciously, as gave me a further encourage-
ment to prosecute these endeavours ; in which I observe it
was my fault to err more through want of care than know-
ledge, which, since, I animadverted it, I have striven with
double care to prevent. I busied myself afterwards in
writing an Almanac Burlesque for the year 1666, but never
offered it to the press.

The spring now approached ; and on the 8th day of April,
about half an hour past two in the afternoon, I applied
myself to that no less honest than able physician, Mr. Wil-
loughby, who (not willing to weaken nature, that was low
enough already, before he strengthened it) prescribed a
cordial yet cleansing drink, which I used for some time;
but without any apparent recruit of strength to my legs at
this time. I had, in the summer of the preceding year,
calculated several new tables, and digested some of them
into a convenient book ; and this year I added some more

328 Life of the Rev. John Flamsteed, [Nov.

unto it, though I had not time, nor ever shall have, I fear,
to conclude and finish it. I also busied myself very much
in calculating the nativities of several of my friends and
acquaintance, which I have since corrected, and shall tran-
scribe on a convenient paper.

The former part of this year had been famous for the
appearance of the comet ; and this was much celebrated by
the report of the cures done in Ireland by Mr. Valentine
Greatrackes, by the stroke of his hands, without the appli-
cation of any medicine. At first, we supposed this to be
only a fiction ; but when the report was cbnfirmed by a
particular relation of several strange cures effected, my
father (who intended not to pretermit any occasion of [my]
recovering in strength) resolved to send me over into Ire-
land, to try if I might, by God*s blessing, receive my strength
again. But, upon some occasion, this journey was put off
till the 26th of August following; when, in the interim,
having some small time, I set myself to write the construc-
tion and uses of a quadrant, with necessary tables for the
framing of the same, as also of a ruler, which I had drawn
with my own hand, fitting both for the latitude of 53°. I
performed it for my loving friend, William Litchford,
beginning it on the 8th of August, and finishing it on the
24th day of the same month. I called it my Mathematical
Essay ^ it being the first piece that ever I wrote for any one ;
and it is still to be found in his hands, for aught I know to
the contrary.

And now, on August the 26th, 1665, being aged nineteen
years and six days, (19^"-, 6^^^% 11^"), I set forth for Ire-
land, with Clement Spicer with me : and on Tuesday, about
noon, we came to Liverpool; where we stayed till Friday
the 1st of September, when the wind turned east. We
embarked in a vessel, called the Supply, about noon : and
on Saturday night came within sight of Dublin ; but by
reason that we wanted water, could not cross the bar that
night. In the mid night we thought to have gotten in with
the tide, but had like to have run upon the Lambay: so
that we cast anchor again, and lay still that night ; and on
the next day, at noon, we put in, but could not be suffered
to land, by reason that the sickness being very hot at that
time in London, all passengers were examined whence they

1835.] First Astronomer- Royal. 329

came, and we not unstrictly. At last, our master went
forth to fetch our tickets, or a licence rather, but returned
not; so that we paid the master's friend, and several slung
down the ropes : till at last a ladder was set, down which
I and the rest of our company descended, and framed our
course on the sands towards the King's End. And here I
have cause to remember the providence of God, who pre-
served me when I had like to have been led a wrong way
by my aged guide, had not those who came behind us
happily turned our course to the right place ; and so we
came to the King's End.

It was night, the doors were shut : and we ran from door
to door to inquire for entertainment ; which at last we got
at a paltry inn, where was no meat I could eat, but brown
bread and ale ; of which I made a hearty meal, and lodged
that night in a straw bed, with a sheet and a half; and yet,
God be praised, I both fed and slept very w^ell. Next day
we got to Dublin, where we stayed at the Ship, in Dame
Street, till Thursday following, when (Sept. 6) we set [out]
on our journey towards the Assaune. We dined at the Naas,
a town accounted handsome amongst them, twelve miles
from Dublin ; and lodged that night at a small town called
Tomalins, paying for our meals sixpence a piece, and yet no
great accomodation. We thought to have lodged at Kill-
cullen, a town six miles from Naas ; but finding that we
had time, we came forward to this town, some four miles
farther.

We travelled, with the mountains on our left hand, on a
fair champaign, free from all difficulties of passage or bogs :
the way being sometimes gravelly, sometimes pasture, or
beaten road, and one of the greatest in the kingdom, not
easy to be missed, except by a traveller that will mislead
himself. It leads from Dublin to Kilkeny, Clonmel, and
Cork. Few hedges to divide the lands or enclosures, but
only banks of about a yard high ; seldom with ditches to
supply their office, which are easily passable by a traveller
(or, indeed, almost anything) anywhere. And in this day's
journey I saw but one wood, besides the Park at Dublin,
which is not accounted any : a thing I thought observable
in a country reported to be so full of them.

The house we lodged at, at our coming in, was strewed
over with gorse, (the usual fuel of the country in that part,

330 Lifeof the Rev. John Flainsteed. [Nov.

where coals are not to be had, except [at] too large rates),
and a barefoot boy was called in to bait a fire, which made
me fear such an entertainment as might be afforded from an
Irish house : but we were brought afterwards into a back
room, indifferently handsome, where we had a table neatly
spread with as fair and fine linen as ordinarily in England,
and accommodation better than I expected.

In the morning (Sept. 8) we rose early to be going on our
journey, and by noon we reached to Carlow, some fourteen
miles from Killcullen, where we baited at a handsome inn ;
and this town is one of the fairest I saw on our journey.
It stands by the side of a river, of an indifferent depth, and
seemed to be indifferent large to me, who had not leisure to
perambulate it, or any other we passed through.

We went forward to Laugh ton Bridge, five miles farther ;
a little town standing upon a large river, passable only, as
I was informed, at the bridge, on which stood a large stone
house, builded, I suppose, for a fort to command that place.
Here we stayed not, but went forward to Goaren, five miles
beyond it. Here we thought to have lodged : but having
time to go farther, we resolved to proceed, and so came to
Bennit's Bridge ; a little town, where, at that time, was
held a fair, composed, for aught I saw, of nothing but sheep,
kine and oxen, of the Irish sort. A company of bouzes
were raised, covered all over with blankets, sheets, rugs,
and linen cloth, fashioned like those in our fairs in England,
but that they were scarce so handsome. They were covered
on every side, so that you could not see into them, except
they were opened, as one of them was by chance as I passed
by it, in which I could perceive nothing but a company of
people set round about the sides of [it] : and whether they
were eating and drinking by turns, as they use to do, I could
not, without too much boldness, attain to perceive. This place
is three miles from Goaren, and stands upon a large river.
Here we thought to have lodged ; but supposing that because
of the fair we could neither have quiet rest nor good accom-
modation, we were persuaded, by a Nottinghamshire man,
seated there, to pass forward to Barneschurch, three miles
farther, a little town, standing partly on a hill ; whither we
went with the people from the fair, and lodged at one Shar-
man's house, where we had indifferent good accommodation.
In this day's journey, as I remember, we saw no woods at

1835.] First Astronomer- Royal. 331

all. When we were at Bennit's Bridge we were but three
miles distant from Kilkenny, the second place in the king-
dom : and hitherto we had a fair road, not easy to be
missed ; but now, having lost it, we had much ado to direct
us in the following part of our journey, which we rose
indifferent early in the morning (Sept. 9) to prosecute.
Leaving Barneschurch, we passed by Newton and Billato-
ben, two towns of Irish built houses; the first two, the
second three, miles distant from Barneschurch ; and so
forward to Nine-Mile House, distant some seven miles from
Barneschurch : thence to Clonmel, nine miles farther, where
we baited, having passed by some small, poor places by the
way, whose names I know not. Here we crossed the moun-
tains, which before were on our left hand ; and here only,
in our going, we lost our way, yet were we never far out of
it. It was after four o'clock in the afternoon when we left
Clonmel ; so that we reached that night no farther than
Castleton, called commonly Four-Mile Waters. And were
advised by a woman, with whom we rode in company, to
cross the waters that night, because the least plash of rain
would cause an extraordinary flood, by reason that the
waters running from off all the adjacent mountains conjoin-
ing, constitute this river.

Our landlord came from Uttoxeter, in Staffordshire, and
was acquainted with my grandfather, Spateman : so that
we were, in all things, very well accommodated for our
acquaintance. On Sabbath morning (Sept. 10), I inquir-
ed where they went to church ; but was -answered that
their minister lived twelve miles off, and that they had no
sermon amongst them , except when he came to receive the
tithes, which was but once a year. And the woman with
whom we came hither told me, in a complaining manner,
that they had plenty enough of every thing necessary except the
word of God; and therewith told me that their minister
lived twelve miles off, at the old Assaune, and came but
once a year at them, as I told you afore. Considering
which, I thought it better to prosecute our journey on the
Sabbath day than to lie in the alehouse ; and so we dis-
charged ourselves, and went to Cappoquin, eight miles
farther, whither we got by noon ; and now we had fixed our
feet at the utmost extent of our journey forward. This is

332 Life of the Rev. John Flamsteed, [Nov.

a small town, and lies upon the river Blackwater, eight
miles up it from Younghall. It had formerly a bridge to
pass over the river; but now hath nothing but a boat for
passengers.

We heard that Mr. Greatrackes used to cure on the
.Lord's-day, Tuesday, Thursday, and Saturday, of course ;
and that the people who lodged at that place when we
alighted were gone, expecting to be touched after sermon.
Therefore, having refreshed ourselves, we went on foot to
the Assaune, about a mile or more distant from Cappoquin,
and entering into his house, we saw him touch several ;
some whereof were nearly cured, others on the mending
hand, and some on whom his strokes had no effect, — of
whom I might have said more, but that he hath been since
in England; and so both his person, cures, and carriage
are well enough known amongst us. And though some
seem to asperse him each way, for my part I think his gift
was of God ; and for the course of his cures, I dare fully
acquiesce with what Dr. Stubbs hath written of him. For
though I am an eye-witness of several of his cures, yet am
not able to remember or fitted to write them out as I saw
them.

I was touched by him on my legs this afternoon (Sept.
11), but found not my disease to stir. Next morning I
came again towards his house, and found him in his own
yard, looking at his cattle. He had a kind of majestical,
yet affable presence, a lusty body, and a composed carriage.
I desired the privilege of his touch, and was granted it pre-
sently ; and saying to him I w^ould not have been so hasty,
had not our horse (which was a gentleman's courtesy to us)
been on so bad a pasture, he very freely bade me bring
him down to his house — he should have good feeding, and
I should pay no more than I was to pay to my former
host. I did so, and saw him put into a good pasture. And
now I was stroked by him all over my body; but found, as
yet, no amends in anything but what I had before I came
to Cappoquin.

This Tuesday morning (Sept. 12) I went down to the
Assaune, and was by him the third time touched ; but not
finding any amends, I determined to depart, and therefore
went to Mr. Greatrackes, purposely to pay him for my

1835.] First Astronomer- Royal. 333

horse's grass, and give him thanks for his courtesies. But
he would not take anything of me : and when I urged him,
saying I had not deserved this civility from him, he answered
me I was a stranger, and he must be so to strangers. So
we came back to Cappoquin, discharged our host, [and]
departed to Clonmel that night, where we lodged at a stately
inn, whose master came out of Derbyshire, our county.
This town is one of the seats of justice in this kingdom, and
here all law businesses may be transacted, as at Dublin.
It is built after the English manner, well fortified with a
strong wall of limestone or marble ; which I have observed
in several of their demolished small castles, to be made of
small pieces, about as- thick again as slates, laid thick in
lime, which will dump any bullet. We entered over a
drawbridge, at which a soldier stood centinel ; a part of
that river, (as I remember) running under it, upon whose
banks it is seated. This river is both deep and broad,
so that the town is almost every way impregnable ; and, in
my mind, it is exceedingly pleasantly seated. From Cap-
poquin hither it is just twelve miles, but long ones.

We departed from Clonmel (Sept. 13), and by that time
we had gotten some eight miles, we perceived that our horse
had lost a shoe. We called at Nine-Mile House, but could
not get a shoe. At one place (I think it was Grangymi-
cleare) we found a smith, to whose shop, when we came,
we saw nothing resembling his trade bat the hearth, bel-
lows, and anvil ; neither iron nor shoes ready-made to be
seen, so poor was the place and the people ; amongst whose
houses, as I remember, I saw but one with a chimney at it —
a certain sign there were no more English inhabitants at
this place.

We travelled nine miles farther to Bennit's Bridge with-
out a shoe, where we baited, hoping assuredly not to miss
of one here ; but the smith was not at home : and because
it was four of the clock, we resolved to go forward to
Goaren, three miles forward, that night. We rode on
hence thither ; where, because it was late when we entered
our inn, we had not time to get him shod this night.

At our entrance we met with some gentlemen going into
the inn, whom we followed ; and being alighted, and a little
refreshed, we met with Mr. Toplady, (whose faj;her was of

334 Life of the Rev, John Flamsteed, [Nov.

Nottingham, and whose brother I had known,) who travelled
towards Dublin to gather his master's debts, who was [a]
trademan in London. He hearing me accidentally name
the place whence I came, inquired several things of Derby.
I asked his name ; but he civilly declined an answer, telling
me he would let me know more next morning (Sept. 14),
when [we] were on our journey to Dublin, whither we
agreed to travel together: with which answer I rested
satisfied.

Goaren is a town consisting of houses built but slenderly,
many after the Irish manner ; only our inns were capacious,
and carried a handsome aspect with them. Hence, having
with some trouble got our horse shod, we departed ; and
when we were on our journey, I renewed our former demand
to Mr. Toplady ; who told me his name, and that he was
servant to Mr. Jekell, of London, and on his business to
travel to the north of Ireland. And as we were inquiring
of his forepassed journey, he told us that the preceding
day, coming over the mountains, and being out of his way,
he met with an Irishman ; of whom inquiring the road to
Goaren, he could get no answer in English, which he sup-
posing to proceed rather from the man's knavery than
ignorance, threatened him, and struck him with [his] whip :
which nothing availing, he laid his hands to the hilt of his
hanger, and threateningly told him — *' Now, sirrah, if you
answer not presently in English, here will [I] make an end
of your days ; at which words the fellow spoke English
presently, and directed him his way very readily. Since
which, he would say. as he travelled with us, he carried his
tobacco by his side. For he used afore to give the Irish
tobacco (of which they are very desirous) to show him his
way ; but now he relinquished that custom, and resolved
to make them do it perforce, and yet not to trust their
perfidiousness.

This morning we got our horse shod with some trouble,
and then discharging our host, departed. We came first
to Laughton Bridge, a very commodious pass, upon a broad
and deep river. Here was a fair kept when [we] passed by ;
in which I saw nothing but Irish beasts, and booths after
their manner : it is five miles from Goaren, and hath some
English-built houses in it. Here we stayed not, but passed

1835.] First Astronomei'- Royal. 335

on to Carlow, where we drank. It is five miles forth from
Laughton Bridge : it is a very handsome place, and one of
the fairest towns we passed through. But it being too soon
to bait, we passed on three miles farther to Castle-Derman,
where we baited at a pleasant inn ; and afterwards passed
on to Kilcullen Bridge, eleven miles farther, where we
lodged that night, well accommodated in an inn that pro-
mised not much at first sight.

Hence next morning (Sept. 15) we hasted indifferent early
for Dublin. At Kilcullen there was nothing observable,
but that it consisted most of Irish houses and buildings.
The bridge is a long mile nearer Dublin than the town, and
is better accommodated with inns, by reason (I suppose)
the river is only passable at that place. From Kilcullen to
Racoole (the next place we came to of note, and where we
baited) is twelve miles : we alighted at the sign of the Post-
boy, and had good accommodation for the time we stayed ;
and after dinner we passed from it. It is a small town ;
the buildings seem ancient ; here many Irish inhabit, and
it is a dirty place. But leaving it at that time, we came to
Dublin, six miles farther, soon enough to make an ill market
afore bed- time; which, for the tediousness of the story, I
shall not relate.

We lodged at our former inn, and stayed here from Friday
night, Sept. 15, till Tuesday the 19th of Sept. When, in
the morning about nine o'clock, we went down to King's
End to take shipping, in the Martin, of Liverpool, to re-
turn ; and quickly came aboard our vessel, which was none
of the best, and we had a sufiicient number of our company.
But before we left the city, we had returned Mr. Mabbot
his horse, which he lent us, with thanks for so obliging a
courtesy, which we could not have merited or expected
from any one. He lent us 40^. at our departure, which we
returned him by Mr. Arthur Bulkeley, who was the occa-
sion of our bad bargain ; and criminal, I fear too, other-
ways towards us, by whom he made his own markets : but
I shall forbear him, because time may afford me satisfaction
from him.

Tuesday, in the afternoon, near three o'clock, we set sail;
but because we had delayed time too much, we were forced
to borrow help to haul over the bar. We sailed that night.

336 Life of the Rev. John Flamsteed, [Nov.

and the next day came before Chester bar about noon ; but
stayed so long in expectation of the high water, that the
tide began to turn before we could get over ; yet we came
to harbour at Liverpool soon after sunset, and landing,
betook ourselves to our former host for entertainment.
We had fair weather and quick speed in our travels and
passage over sea, the winds, standing fair for us, both as we
went and came ; for which providence I have cause to
praise God continually.

We heard this night that there was a carrier in town, on
whose horses we might travel homeward as far as Holmes-
chapel. We met and agreed with him; and the next day,
being Thursday, Sept. the 21st, about noon, we left Liver-
pool, and came that night to Zanchy Bridges, where we
lodged that night. And the next day, being Friday, the
22nd day, we passed from thence to Warrington, and so,
by the Cock to Budworth, to Holmeschapel ; where the
carrier set us down, and would not be persuaded to carry
us any farther. We saw nobody on the way to Congleton
that might carry us thither : till at last a carrier passed by
with three horses, whom, with much ado, after he was
passed by, we got to come back. With him we bargained;
and, discharging the other, set forward for Congleton,
whither we came at night, and where I alighted at Mr.
Hunford's. But intending to lodge at Mr. Mottershead's,
my father's host, I was told by him that he durst not afford
me lodging, because the sickness (which was then rife, and
raged much in several places) was reported to be in Liver-
pool, whence we came, and his neighbours would asperse
him for it if he should admit us. So that I was forced to
change my intended lodging, and lie at Mat. Lowneses's,
who was one of my father's customers ; where I was in-
differently well accommodated. Next day, being Saturday,
the 23rd of Sept., we parted from Congleton, and rode to
Longshaw, by Leek (where w^e had left a horse of our own)
and paid for the horses which had brought us thither. It
was before noon that we got to Longshaw, where we stayed
not long, but passed on for Ashbourne ; and at night, when
we came to Brailsford, our horse stumbled and overthrew
us both, but (I thank God) without hurt. And so we sped
safe to Derby at night, after daylight was ended, which we

1835.] First Astronomer- Royal. 337

had left on that day month before. For God's providences
in this journey His name be praised. Amen, Amen.

Being returned I was visited by my friends, I being so
discomposed by my journey that I was not very fit to appear
at court that day, yet had I not been so ill but that riding
on a dull horse (who trotted hard) betwixt Holmeschapel
and Congleton, I was a little galled. For I would not use
that practice, which an Irish gentleman reported who had
his horse's back galled always when he was ridden by one
of his boys ; at which wondering, he by chance meets his
said boy, who was a natural Irishman, riding upon his galled
horse with his breeches hanging buttoned upon his neck ;
of which inquiring of him the reason, he answered it was
because the horse should not gall him, but by that means
the rider escapes and the horse is galled himself. This
story I could not omit, because such passages are not usual
among the English, to whom this scarce was known.

Not long after my return I added an appendix to my
Mathematical Essays, which I had left in the hands of my
friend W. Litchford, and intended for him, and I gave it
him when I had finished it. I added to it the projection of
an universal dial, and a catalogue of seventy of the fixed
stars, with their right ascensions, declinations, longitudes
and latitudes, to the year 1701 ; which I had composed by
the Tychonic places, and allowing the annual procession of
the fixed stars 50".

I also proceeded to perfect the calculation of the solar
eclipse, which should happen June 22d, 1666, in the morning,
according to the Caroline Tables, in which I noted some
incongruities and difficulties of calculation I now remember
not ; only I found by his tables at Derby,

In the eclipse of the sun June 21st 1666 or 22d, mane

Initium eclipsis .

. . 17^-

b^^

• 7»-

Hora conjunctionis .

. . 18

43

36

Maxima observatio .

. . 18

48

37

Finis

. . 19

48

46

Duratio tota . . .

. . 1

55

39

Digiti eclip. 7° 28' ad Aust.
In the winter following I was indifferent hearty and my
disease was not so violent as it used to be at that time for-
merly. But whether through God's mercy I received this

VOL. II. z

338 Life of the Rev. John Flamsteed, [Nov.

from Mr. Greatrackes's touch, or my journey and vomiting
at sea, I am uncertain ; but by some circumstances I guess
that I received a benefit from both.

February 12, 1665-6, 1 went to Worcester where Mr. Great-
rackes, who was then come to England, was, and was once
stroked by him, but with no better effect than formerly,
though several then were cured.

At Lenten assizes, 1666, on the Sabbath after the evening
prayers I was visited by Mr. Imanuel Halton, of Wingfield
Manor. I had heard of him and he of me, formerly, by my
cousin Wilson. We being strangers to each other and not
having seen one the other formerly, to our knowledge,
talked somewhat reservedly at first, after more openly.
Amongst other of my papers I showed him my calculation
of the aforesaid solar eclipse which he accounted of more
than any other and desired a transcript of it. I likewise
showed him a small canon of natural and artificial versed
signs which he much commended and of which I afterwards
sent him a copy. So we parted at that time with mutual
promises of a future acquaintance. Not long after he came
to town and we met again ; when he promised me a sight
of the Richleian Tables (which soon after he sent me) com-
posed by Natalis Durret, a Frenchman, more laborious in
my opinion, than ingenious — if at least those tables be his
which he exposes in that name ; for I suppose they are
rather the Rudolphine reduced and enlarged by him. But
the prescript to the tables (which is full of various faults
not to be excused by the press) I suppose may be wholly
his ; for the ingenious Kepler could hardly be thought
guilty of such oversight or rather errors. However, because
the introduction was filled with some things I had not seen
before I translated it for my own use into English, and it
will be found amongst my papers. However, that I might
not seem to find a fault and leave it as I found it, I corrected
the piece in the margin ; and so returned [it] to its master
with thanks for the obliging courtesy.

Soon after having occasion to write to him again to desire
him to observe the solar eclipse I had calculated, I intimated
in my letters that I wanted some solar observations — which
when he understood he sent me the first tome of Riccioli's
new Almagest in Latin ; which I joyfully received because

1835.] First Astronoinej:- Royal. 339

it showed a method of finding the sun's true parallax (by
observations of the moon's dichotomy) which I was very
desirous of investigating at that time. But more of this
hereafter. I spent some part of my time in astrological
studies, but so as my labours were rather astronomical.
Amongst others I spent some time on Mr. Linacre's and
another great person's schemes ; yet could I not anyways
satisfy myself in the arcs of directions for the measuring of
time, nor am I yet perfectly satisfied. Yet I think Kepler's
measures most rational and best grounded ; though in the
great person's nativity which I directed I used Naboyd's
measure, which is most in use amongst astrologers. In
fine, I found astrology to give generally strong conjectural
hints not perfect declarations.

Healthful, and in these studies, I spent the summer [of]
1^66. And now, August 19th, 1666, 1 was aged just twenty
years, whence I begin a perfecter account of myself. After I
had received Riccioli's^Zwzo^e^^ I set myself to read him when
an intermission from my father's business happened ; which
usually did at night in winter ; and I took much pleasure
in him. I found he differed from Tycho in the places and
distances of the fixed stars sometimes 4'. His obliquity
of the ecliptic, Riccioli confirms by his own observations :
to which and the sun's parallax deposed by him I shall say
more in my astronomical works.

Thus I held on till December the 6th, when I found my-
self much pained with the headache and some other dis-
tempers ; which after a while reduced me to my usual win-
ter weakness and left me as ill as formerly. I continued
afflicted with a small pain and some grudgings of the head-
ache for a month after, so that I ended the year 1666 and
began 1666-7 with it.

I transcribed some things from Riccioli, and taking occa-
sion to peruse his method of finding the sun's distance by
the moon's dichotomy, 1 could not but observe how he
introduced an arc for correcting the apparent dichotomy
and reducing it to the true which cannot be admitted. For
he supposes the moon's parallax to cause her to appear
hollow at the dichotomy next succeeding the new moon,
and more than half full at [the] dichotomy preceding the
change ; which I shall note to be so in my astronomical

z2

340 Life of the Rev. John Flamsteed, [Nov,

works. In the mean time whoever will but read what he
hath written (page 733, the third problem) will find how
groundlessly he introduceth it, if they but seriously consider
that the difference of the parallax of the moon's centre and
her superior horn is equal to the difference of the parallax
of her centre and her inferior horn; with a very small
difference which will scarce ever arise to half a second were
her diameter double the breadth it is.

Some considerations, likewise, of the different equations
of time used by several astronomers, though well demon-
strated by none, caused me to strive for a demonstrable
equation. I studied hard in this, and at first was of opinion
that the natural days were always equal, and that there
needed no equation of time. Whilst striving to demonstrate
this I proved the contrary : first that the excentricity of the
earth's orbit from the sun's centre caused an inequality ;
and afterwards that the ecliptic's obliquity caused another
inequality of the apparent day, which two causes applied
together would make the absolute equation of time. But
because I have elsewhere said enough of this already in a
letter of three sheets to Mr. Halton, I shall say no more of
it in this place. I likewise endeavoured something in the
obliquity of the ecliptic ; the sun's true distance from the
earth, and the mean length of the tropical year; in all
which I have laboured with much difficulty this last April.
And now I have brought my sheets up to my age, and have
finished this the 8th day of May 1667. Deo gloria.

[Here this portion of the M.S. terminates. But Flam-
steed has added a kind of postscript thereto, which being
short, the Editor transcribes.]

Afterwards I followed my mathematical studies closer,
but kept no special account of my proficiency. I met with
new authors, read something of Euclid and employed myself
in several readings till the latter end of the year 1669, when
I wrote an Almanac for the following year, not after the
usual manner but much more accurately; inserting an
eclipse of the sun that might have been observable, but was
omitted in the Ephemerides, and five appulses of the moon
to fixed stars.

But this being rejected as beyond the capacity of the
vulgar, and returned to me, I excerpted the eclipse and

1835.] First Astronomer- Royal. 341

appulses, and addressed them with some astronomical
speculations to the Royal Society, suppressing my name
under my anagram. My little labour was better accepted
than I expected — I received a letter of thanks from Mr.
Oldenburg the Secretary of the Society. My papers I sent
to Mr Stansby : he delivered them to Mr. Ashmole the
great lover of curiosities ; and he presented them to the
Royal Society.

They procured me a letter from Mr. Collins also, with
an account of several new authors, and a promise of a good
correspondence, which he maintained very ingeniously
afterwards, procuring me many things I wanted. The
second letter I had from him was dated Feb. 3, 1669-70.
My first from Oldenburg was dated Jan. 14, 1669-70.

After Easter Term, I made a voyage to see London :
visited Mr. Oldenburg [and] Mr. Collins. And was by the
last carried to see the Tower, and Sir Jonas Moore who
presented me with Mr. Townley's micrometer, and under-
took to procure me glasses for a telescope to fit it, for
which I left three guineas in Mr. Collins' hand, but got
not the glasses (being a twelve foot tube) till Sept. 18th,
following. This was the beginning of my acquaintance*''^*
[The MS. here ends abruptly.]
( To be continued, J

Article II.

Researches into the Nature of the Decolourizing Combinations

of Chlorine, By A. J. Balard.

{Continued from p. 271.)

3. Properties of the Aqueous Solution of Chloi'ous Acid. —
Chlorous acid, when diluted with water, is a transparent
liquid, slightly coloured yellow when in a concentrated
state. Its smell is distinct from that of chlorine and deu-
toxide of chlorine of Davy, but approaches the first more
nearly than the second. Its taste is stronger, but not acid.
It attacks the epidermis with greater energy than nitric
acid, producing a reddish-brown spot.

It partially decomposes at common temperatures, and, in
summer, can only be preserved in ice, except when dilute

342 M. Balard on the Nature of the [Nov.

and kept from the light. At 212° it is only partially de-
composed.

By the action of a strong light it is converted into chlo-
rine and chloric acid, and sometimes, also, deutoxide of
chlorine is formed. When exposed to the voltaic action,
oxygen is disengaged at the positive pole, but the bleaching
power remains, and no chlorine appears at the positive pole.
In this experiment the chlorous acid and water are decom-
posed, and muriatic acid is formed. This idea is confirmed
by the fact, that after sometime, the oxygen collected is
mixed with chlorine.

Chlorine has no action on the aqueous solution of chlo-
rous acid.

Bromine, when a drop of it is brought in contact with
chlorous acid, expels the chlorine and forms first a chloride
of bromine, which changes into bromic acid.

Iodine presents the same action, but with more energy.
Heat is disengaged, and chloride of bromine and iodic acid
are formed. The acid produces, with nitrate of silver, a white
precipitate of iodate of silver soluble in ammonia; it is
not, therefore, hyperiodic acid, as stated by Magnus and
Ammermutter.

Hydrogen, Azote, and Carbon, have no action upon chlo-
rous acid ; but phosphorus, sulphur, selenium, and arsenic,
act upon it with great energy, giving origin to sulphuric,
selenic, phosphoric, and arsenic acids, a disengagement of
chlorine, and the formation of chlorides of phosphorus, <fec.,
which undergo a double decomposition in contact with
water, the products being water and phosphoric acid, &c.

Potassium forms with chlorous acid, chloride of potassium
and chlorate of potash.

Iron filings decompose the acid instantly. Heat is emitted
and perchloride of iron formed, mixed with chlorate.

Zinc, lead, tin, and bismuth, have no action unless another
acid be present, when the metal decomposes the acid and
sets chlorine at liberty, and not hydrogen, which would
happen if water were decomposed.

With copper, chlorine is disengaged, mixed with some
oxygen, chloride of copper being formed. With mercury
a similar action occurs, but with silver no chlorine is dis-
charged, chloride of silver being formed. Chlorous acid

1835.] Decolourizing Combinations of Chlorine. 343

appears to be, therefore, superior to nitric acid, and even,
in a certain measure, to peroxide of hydrogen, for the
purposes of communicating oxygen to substances ; but still
it may be proper to rank it under nitric acid, as its oxy-
dating properties depend upon its disposition to form a
nitrate, soluble in acid.

The different chlorides and bromides of carbon are but
slowly acted on by chlorous acid ; but the periodide of carbon
is attacked with great energy by chlorine, carbonic acid
and carbonic oxide being disengaged, and iodine precipi-
tated, while iodic and muriatic acids remain in solution.

Cyanogen precipitates an oily liquid, which appears to be
a mixture of chlorides of cyanogen and azote ; muriatic and
cyanic acids being dissolved, and a mixture of chlorine,
azote, carbonic acid, and a little chloride of cyanogen, pre-
senting themselves in an elastic state.

Sulphur et of Phosphorus and Sulphur et of Carbon are con-
verted, respectively, into sulphuric, phosphoric and muriatic
acids, and into sulphuric and muriatic acids, with some
chloride of sulphur, and the disengagement of chlorine and
carbonic acid.

defiant gas and chlorous acid give origin to chloride of
carbon and chlorine.

Ammonia and chlorous acid act differently according to
circumstances. When ammonia is poured into the acid,
azote is disengaged, and probably chlorite of ammonia is
formed. Chloride of azote may be formed by suspending a
portion of an ammoniacal salt in dilute chlorous acid.

Phosphuretted and arsenietted hydrogen are converted into
phosphoric, arsenic, and muriatic acids, and sulphuretted
hydrogen undergoes a similar change, but without the
emission of light, although the heat disengaged is very
considerable.

The hydrogen acids present, with chlorous acid, similar
phenomena. In operating with hydriodic acid gas, water,
iodic acid and chlorine are formed, and much heat is dis-
engaged.

With anhydrous hydrocyanic acid chlorine is produced ;
and the liquid, besides muriatic and cyanic acid, contains a
great quantity of chloride of cyanogen.

The metallic sulphur ets treated with liquid chlorous acid

344 M. Balard on the Nature of the [Nov.

are changed into sulphates. Heat and chlorine are dis-
engaged, and sometimes the odour of chloride of sulphur is
perceptible. Analogous results are obtained with phos-
phuret of lime.

In the action of chlorous acid upon compound combus-
tibles, its two elements combine with the two constitu-
ents of the latter, the oxygen separating and leaving to the
chlorine the most electro-negative of the two, as in the
action of olefiant gas and ammonia. In other cases the
chlorine combines with a portion of the electro-negative
element, but there is disengaged a quantity of gas propor-
tional to the elevation of temperature. When it is raised
to incandescence, the two elements of the compound com-
bustible are almost entirely consumed by the oxygen, as if
the affinity of the latter for bodies increased with the tem-
perature, in a proportion greater than that of chlorine itself.

It might be supposed that the composition of the chlorous
acid is such, that the electro-negative element of the com-
pound combustible being saturated with chlorine, an excess
of this gas would remain, but this is not the case. In com-
paring its composition with that of phosphuretted hydrogen,
we find tWt^ even in admitting that all the hydrogen was
consumed by the oxygen, the quantity of chlorine is insuffi-
cient to combing with the phosphorus. However, in this
decomposition, a great proportion of this gas is set at liberty,
which renders it probable that, in this case as well as in
many others, the elements of the compound combustible are
both combined with the oxygen of the chlorous acid.

It is easy to perceive, from this, what will happen when
chlorous acid is brought in contact with combinations which
are not saturated with oxygen. These compounds are almost
always peroxidized, and chlorine gas is set free.

There are some oxides, such as carbonic oxide, which do
not appear to be altered by chlorous acid, but with oxalic
acid the most energetic action takes place. If a portion of
this acid is projected into chlorous acid, much heat is extri-
cated, and a violent effervesence originates, from the disen-
gagement of carbonic acid and chlorine. Protoxide of azote
is not changed by chlorous acid, but all the other combina-
tions of azote give rise to the production of nitric acid and
chlorine.

1835.] Decolourizing Combinations of Chlorine. 345

Hyposulphuric acid is not changed, while sulphurous
acid, either gaseous or liquid, is converted into sulphuric
acid. Hence, this may afford an argument to chemists who
consider the first acid as a compound of sulphuric and sul-
phurous acid.

All the compounds of oxygen and phosphorus are imme-
diately changed into phosphoric acid. The same happens
with arsenious acid and selenious acid, which are converted
into arsenic and selenic acids, with the disengagement of
heat and chlorine.

The metallic oxides are peroxidized, as the protoxides of
iron, tin, manganese, nickel, cobalt, and lead. Protoxide
of chromium is changed into chromic acid. Chlorous acid
has no action, however, upon oxide of bismuth and per-
oxide of manganese. Although, in some instances, chlorous
acid may contribute oxygen to the alkaline oxides, it com-
monly simply combines with them, and sometimes it de-
composes the peroxides, discharges oxygen and forms chlo-
rites. It acts thus with peroxide of barium, with peroxide
of lead and the two oxides of silver, metals which form in-
soluble compounds with chlorine ; chlorides, and not chlo-
rites are formed, oxygen being disengaged, mixed with
chlorine. The metallic chlorides are decomposed by chlo-
rous acid. This decomposition is always accompanied with
a copious disengagement of chlorine, and the metal is oxi-
dized. The product depends evidently on the manner in
which this oxide acts, both with chlorine and chlorous
acid. Thus, the chlorides of the alkaline metals form mix-
tures of chlorides and chlorites. Those of manganese, iron,
nickel, cobalt, lead and tin, give origin to chlorine and
peroxides. That of copper forms chlorine and muriate of
copper. The protochloride of mercury is changed without
disengaging gas, into a red powder, which is undoubtedly
a muriate mixed with the oxide (oxido-chlorure). The
deuto-chloride of mercury and the chloride of silver are
also attacked by chlorous acid, but very slowly. Chlorine,
with some oxygen, is disengaged. It is not easy to account
for the presence of the latter.

The bromides of potassium, mercury, and silver, in con-
tact with chlorous acid form chlorine, bromine, chloride of
bromine, and a bromate and metallic chloride.

346 M. Balard on the Nature of the [Nov.

The iodides of potassium, mercury, and silver, produce
similar phenomena.

With saline compounds the action is various. With
carbonates of soda and lime the acid is driven off and chlo-
rites are formed. Chlorous acid partly displaces acetic acid
from the acetates, the smell of acetic acid being distinct,
and a chlorate is formed.

Bromic acid is displaced from its combinations by chlorous
acid, in a similar manner as in the case of the acetates.

With regard to the action of chlorous acid upon salts, as
an oxydating agent, the explanation is simple.

It acts as if these acids were free ; that is to say, without
acting upon the salts whose acids are saturated with oxygen ;
it converts to this state those which are not so. Thus, the
oxalates are changed into carbonates, the sulphites into
sulphates ; these decompositions being attended with the
extrication of chlorine and heat, without any alteration
being produced in the neutrality of the salt. The iodites
and chlorates are not, however, changed into hyper-iodates
and hyperchlorates. The same anomaly occurs here as was
noticed in the action of chlorous acid upon the free acids.
The hyposulphate of barytes, which nitric acid converts into
sulphate, undergoes no change from chlorous acid.

Chlorous acid changes the protoxides into peroxides, pro-
vided that the latter are capable of neutralizing acids.
Thus, the salts of the protoxides of iron, copper, and tin,
are immediately transformed into peroxide salts ; but those
of nickel, cobalt, and lead, undergo no alteration ; the base,
in these cases, if peroxidized, would cease to saturate the
acids, and the action of the chlorous acid would be to destroy
a combination already existing, in place of contributing to
form more neutral and fixed compounds, as when it changes
ite into ate salts.

However, the salts of protoxide of manganese, treated by
chlorous acid, deposit peroxide, and the liquid becomes
acid ; but the action is so slow, that it may be attributed to
the disengagement of chlorine, which always accompanies
the spontaneous decomposition of chlorous acid, and not
to this acid itself. Organic substances, as might be
expected, are powerfully acted on by chlorous acid, the
reaction being generally accompanied with the disengage-

1835.] Decolourizing Combinations of Chlorine. 347

ment of chlorine, mixed with variable proportions of car-
bonic acid gas. When the substance contains azote, the
latter is disengaged in the form of chloride of azote. This
happens with urea, uric acid, and the vegetable alkalies
which do not appear susceptible of forming chlorites. In
some cases the quantity of carbonic acid represents the
oxygen which enters into the composition of chlorous acid.
This occurs with indigo, which chlorous acid transforms
into a bitter yellow matter, soluble in alcohol. In most
cases little carbonic acid is obtained, a notable portion of
the oxygen disappearing, and contributing to form more
oxidized compounds. Thus, the products of its action upon
sugar, gum, and starch, &c., are strongly acid. Sometimes,
however, the decomposition is latent, and the two elements
of the chlorous acid are absorbed at the time by the organic
matter. This is what happens with alcohol. By its mix-
ture with chlorous acid this liquid is changed into acetic
acid, and, at the same time, a certain quantity of oily liquid
is formed, the product of the action of chlorine upon alcohol.

These observations are sufficient to prove that, in its
action upon organic matter, chlorous acid acts principally
by the oxygen which it contains. Hence, it is natural to
infer that our knowledge of chlorous acid may, in an indi-
rect manner, contribute to the progress of organic chemistry.

4. Of Chlorous Acid Gas. — I had observed, in several
trials, that the aqueous solution of chlorous acid, when
exposed to the contact of air, lost, in a short time, its
colour, and a great portion of its smell. These changes
made me suppose that it was very volatile, and might admit
of its readily being obtained in the gaseous state.

I tried, at first, the action of heat upon concentrated
liquid chlorous acid. At a temperature a little below that
of ebullition, a small quantity of a yellow coloured gas was
discharged through the mercury in small bubbles, was
absorbed, and left a residue of oxygen. The liquid pre-
served even after exposure to a temperature near that of
ebullition, the power of acting upon combustibles with the
same activity as before.

Hence, I concluded that chlorous acid had a great affinity
for water, and that, by the action of a substance possessing
a strong disposition for water, the chlorous acid might be

348 M. Balard on the Nature of the [Nov.

obtained in a gaseous state. Sulphuric acid was used for
this purpose ; a gas was procured, but, instead of being
of the deep yellow colour, and having the smell of liquid
chlorous acid, it rather resembled deutoxide of chlorine.
The acid was changed into deutoxide of chlorine, chlorine,
and oxygen.

I had nearly concluded that chlorous acid, like nitric,
chloric, and bromic acids, could not exist without water ;
but, before being satisfied with"^this idea, I considered it pro-
per to try the effect of an agent, which, though possessing
an affinity for water, was less powerful than sulphuric acid.
Nitrate of lime was adopted. When a mixture is made of
equal parts of liquid chlorous acid, and dry nitrate of lime,
a lively effervescence takes place ; a gas is disengaged, which
re-dissolves in the water, and possesses all the properties
of liquid chlorous acid. The same result was obtained by
using phosphoric acid (not prepared from the phosphate of
ammonia, because, the ammonia which the acid, in this
case, always contains, would produce chloride of azote, and
consequently explosions). If the gas is collected in a mer-
curial trough, in the usual way, it acts upon the metal, and
nothing remains but oxygen. The following method was,
therefore, adopted ;

After having introduced into the upper part of a vessel
filled with mercury, about yV ^^ its volume of concentrated
chlorous acid, fragments of dry nitrate of lime were gradu-
ally passed up. The gas was disengaged in the effervescence,
and, as it did not touch the mercury, from which it was
separated by the solution of the nitrate, it was preserved in
the jar for a long time. It may be transferred from one
vessel to another, when the manipulation is performed
rapidly, because it is not decomposed by the metal when it
passes through it rapidly, and in large bubbles.

Chlorous acid gas possesses a yellow colour, which is
somewhat darker than that of chlorine, with which it
is apt to be confounded. Its odour resembles that of the
liquid acid. It is completely absorbed by mercury, which
is converted into muriate and oxide (oxido-chlorure). Water
absorbs a hundred times its volume of the gas. A some-
what elevated temperature suffices to separate the elements
with an explosion, much heat and light being disengaged.

1835.] Decolourizing Combinations of Chlorine. 349

Although it is more difficult of decomposition than the
oxides of chlorine, I have seen it detonate while conveying
it from one vessel to another. It is proper to add the nitrate
of lime cautiously, in order that the heat developed during
the solution of the salt be moderate. I have seen the gas
detonate from this cause.

Exposure to a weak light for some hours did not affect it,
but the solar light decomposes it in a few minutes, without
detonation.

Oxygen and chlorine have no action upon chlorous acid
gas. Hydrogen does not act upon it at common tempera-
tures, but if a lighted candle is brought in contact with a
mixture of these gases, a strong detonation is produced, and
white vapours of muriatic acid gas appear.

I have not tried the effect of boron and silicon upon it,
but I have determined the action of bromine and iodine,
which form with it chloric and bromic acids, and chlorides
of bromine and iodine, without detonation.

Sulphur, selenium, phosphorus, and arsenic, have the same
action, but are decomposed violently with much light, and
give rise to sulphurous, selenious, or selenic, phosphoric
and arsenic acids, with some free chlorine. When we
operate with charcoal there is a detonation, but the gas
produced is a mixture of oxygen and chlorine, and contains
very little carbonic acid. This decomposition appears to be
produced by the absorption of the gas in the pores of the
charcoal.

The metals act differently with chlorous acid gas, according
to the circumstances in which they are brought in contact.
If fragments of different metals, enveloped in varnished
paper, be introduced into a narrow vessel containing a
small quantity of chlorous acid, complete absorption takes
place in the course of a few minutes, without detonation.
An oxide and chloride are formed at the same time. But,
if the quantity of chlorous acid amounts to some cubic inches,
the absorption, which begins very gently, terminates by a
detonation with disengagement of light, and in the upper
part of the vessel we find a mixture of chlorine and oxygen.
It is probable that the heat developed in this case by the
chemical action, produces the decomposition of that portion
of the gas which has not yet been absorbed. Silver leaf
acts also in a certain time upon chlorous acid. The metal

350 M, Balard on the Nature of the [Nov.

is partially converted into chloride, and oxygen is disen-
gaged ; but the heat developed by this reaction decomposes
part of the gas, and chlorine remains, mixed with oxygen.

The chlorous acid is equally decomposed by most of the
compound combustibles.

Cyanogen and chlorous acid gas act mildly upon each
other. In a short time, however, we find in the vessel
chlorine, carbonic acid, and azote ; and the gaseous mixture
exhales the odour of chloride of cyanogen.

Carburetted hydrogen does not act upon chlorous acid,
but this acid and defiant gas are decomposed without dis-
engagement of heat and light, water and chloride of carbon
remaining

Phosphuretted, arsenietted, and sulphuretted hydrogen
gases, on the other hand, detonate, and chlorine mixed
with a little oxygen, remains. The combination of sulphu-
retted hydrogen is accompanied with a blue flame similar to
that exhibited when sulphur burns in the open air. The
detonation which ammonia produces is also very lively, and
in this case, as in the preceding, much chlorine is set at
liberty. The sulphuret of carbon produces also an explosion,
after which we find in the vessel sulphurous and carbonic
acid. The smell of the gas indicates that a little chloride
of sulphur is formed at the same time.

The decomposition of chlorous by muriatic acid is accom-
panied with the extrication of heat without disengagement
of light. The same happens when we operate with hydri-
odic acid.

The phosphuret of lime decomposes chlorous acid with a
brisk detonation, and the gaseous residue contains much
chlorine.

Most of the sulphurets, as those of barium, tin, mercury,
antimony, &c., speedily produce the same effect.

When the gas is small in quantity, the absorption may
take place without detonation supervening. In the last
case the smell indicatestheformationof chloride of sulphur.

Oxalic acid also decomposes chlorous acid without pro-
ducing an explosion.

Carbonic acid decomposes, slowly, chlorous acid gas. In
a short time the colour of the mixture disappears, and the
gas possesses the pungent odour of chloro -carbonic acid gas.

Protoxide of azote does not appear to undergo any altera-

1835.] Decolourizing Comhinations of Chlorine, 351

tion from the action of chlorous acid, but with the deutoxide
a violent detonation takes place. This is accompanied with
the production of nitrous gas, which new bubbles of chlo-
rous acid may transform into nitric acid. Dry sulphurous
acid gas is freely acted on by chlorous acid. In a few hours,
however, the gaseous mixture placed over the mercury has
disappeared, and the sulphurous acid is changed into sul-
phuric acid.

When blotting paper is brought in contact with chlorous
acid gas a detonation takes place, and in the vessel are found
oxygen and chlorine, nearly in the proportion to form chlo-
rous acid, which shews that the gas has detonated princi-
pally by the heat disengaged in its action upon the paper.

Indigo decomposes chlorous acid without detonation, and
forms a yellow coloured compound. A volume of carbonic
acid is formed, much inferior to that of the oxygen which
the acid employed contained ; and the chlorine extricated,
is partly absorbed by the mercury and partly retained in
the pores of the vegetable matter, in consequence of which
acid vapours are disengaged when heat is applied.

The facts detailed prove that chlorous acid, in the gaseous
state, acts nearly as when liquid. It might at first be
thought, that the free chlorine found in the vessel, proceeds
from the decomposition of a portion of the gas, induced by
the rise of temperature, which is produced by the action of
the compound combustible ; but only a portion of the chlo-
rine can be ascribed to this source. Because the quantity
of oxygen with which it is mixed, is almost always inferior
to that which in chlorous acid is united with the volume of
chlorine which is obtained. Hence, it is probable, that in
these cases the two combustible elements of the compound
are principally combined with the oxygen.
(To he continued.)

Article III.

On the number and character of the Colours that enter into
the Composition of White Light. By P. C.

( Continued from p. 179. J

If we suffer the direct light of the sun to fall on a prism,
and receive the spectrum upon a screen in the usual manner,

352 P. C. on the Colours that enter into the [Nov.

by varying the distance of the screen it may be observed in
different stages of its developement. If we look at the
spectrum thus formed, through an orange-yellow glass,
which we have already stated is nearly opaque to violet
light, we shall find that the violet part of the spectrum will
disappear, and that the blue which is found in it previous
to its full developement, will invariably be converted to a
green. If the spectrum be completely developed, the violet
only will disappear, leaving the red and green very little
altered in their appearance by the interposition of the
coloured glass.

Now, if blue be a simple colour, upon what principle is
this conversion made 1 The yellow glass may refuse trans-
mission to one of the constituents of a compound colour,
but it cannot add to a simple colour ; it may weaken it, but
it cannot change its character.

If we look through the yellow glass at the spectrum in
an early stage of its developement, before the white centre
has entirely disappeared, this white will be converted to a
yellow : the violet will disappear, and the blue be changed
to green, as usual.

The yellow centre, then, is evidently white light from
which the violet has been withdrawn, or the complement of
violet light : it follows, that if green be a compound of blue
and yellow, it must enter into the composition of one of its
own constituents ; for green is transmitted by the coloured
glass, and, of course, must form part of the yellow centre.

We may vary the experiment, by placing the coloured
glass which refuses transmission to the violet light, either
before or behind the prism ; and we shall then have a spec-
trum formed of only two of the primitive colours ; which,
in its early stages, will exhibit red, the least refrangible of
these colours, on one side; and green, the most refrangible,
on the other ; separated by a yellow, formed by their super-
position .

This experiment alone would decide the question at issue;
the spectrum which is formed by it never exhibits more
than three colours, red, yellow, and green ; one of which,
the central yellow, is evidently, from its disappearance in
proportion as they are developed, a compound of the other
two.

It is probable that the communication of this orange-

1835.] Composition of White Light. 363

yellow colour to one of the glasses of a telescope, would, in
many cases, be attended with advantage. The opacity of
colouring matter used in giving this tint to glass, is so de-
cided to violet light, that a piece of it in my possession, the
colour of which is confined to one surface of the glass, upon
which it forms a mere film, appears to exclude it almost
entirely; while it freely transmits the green and red. No
other colour can be so completely excluded, by any means
with which I am acquainted, without a considerable depth
of the medium, and a consequent loss of the two colours
which it is the object to preserve.

Sir David Brewster, in his treatise on Optics,* suggested
such an improvement under an impression that yellow is a
simple colour, and, consequently, that it would render the
telescope monochromatic ; but although I do not consider
this opinion correct, I think the advantages anticipated by
Sir David Brewster will not be lessened by it ; as it appears
two, instead of one, of the most luminous colours will be
admitted ; and the images formed by them, it is probable,
may be corrected with greater ease and precision than when,
as at present, we have three colours to contend with.

One of the great defects of the telescope, it is well known,
arises from the want of perfect coincidence in the indepen-
dent images formed by the light of different colours. The
colours which surround the collected images are not the
cause af this defect, but one of its consequences, and, there-
fore, an indication of its existence ; but their removal,
supposing the colourless part to remain unaltered, would
not produce the slightest advantage.

Let us suppose that we have three pictures so precisely
alike that if they were placed upon each other the different
objects represented in them would exactly correspond; let
us further suppose these pictures to be transparent, and
that white objects are represented on one picture red, on
another green, and on the other violet. Now, it is evident
that if it were possible to form such an arrangement, and
that the light transmitted to the eye from the three pictures

* If we could obtain a solid or a fluid which would absorb all the other rays of
the spectrum but the yellow, with as little loss as there is in red glasses, a telescope
of the preceding construction would answer for day objects, and for all the pur-
poses of astronomy. — Treatise on Optics, Lardner's Cyclopedia p. 368.
VOL. II. 2 A

354 P. C on the Colours that enter into the [Nov.

were in the proportion which forms white light, all these
objects would be white, without the least appearance of
colour. This is precisely what we should have in the field
of view with a perfect telescope.

But if, instead of being of the same dimensions, we sup-
pose the pictures, preserving their correspondence in every
other respect, to be drawn upon different scales, the violet
picture, for instance, a little larger than the green, and the
green a little larger than the red, it is obvious that when
they are placed upon each other, the want of correspondence
will be found throughout the whole ; and though the defect
will gradually increase from the centre as we proceed to
the circumference, there will not be a single object the
three images of which will perfectly coincide. It will be
no remedy for this defect in the telescope, therefore, to
absorb the violet which extends at the edges beyond the
green; and the blue, formed by the green and violet,
which is seen beyond the red, where all the colours meet
and form white ; unless we extend the operation to every
part of every object in the field of view, and thus render
the whole monochromatic : any thing short of this might
still leave the head of one animal in red light upon the
shoulders of another in violet light, and, by other trans-
fers, upon the same principle, produce such confusion as
would, at least, preclude the possibility of a distinct percep-
tion of minute objects : it would be like cutting the edges
of the pictures we have been speaking of, so as to reduce
them to the same dimensions, leaving minute objects, re-
presented upon them, mixed together in endless confusion,
and the different parts of larger objects in the same disjointed
state, though they would in some degree preserve their pro-
per colours by a system of mutual compensations.

This defect is lessened, but not cured, in the achromatic
telescope. Sir D. Brewster informs us that " all achromatic
telescopes whatever, when made of crown and flint glass,
exhibit the secondary colours, viz. the wine-coloured s.nd the
green fringes." (p. 369.) The wine-coloured fringes are
formed of red and violet, of which green is the complemen-
tary colour ; the former are seen upon one edge of white
objects, and the latter upon the opposite edge, from the
want of exact coincidence between the differently coloured
images ; and they cannot be entirely removed but by either

1835.] Composkion of White Light, 356

bringing the images into a position in which they exactly
correspond, or absorbing the whole of the colour, or colours,
of which they are formed.

If we direct a common telescope to an uniform surface of
white light, the field of view will be surrounded with blue
and violet fringes ; the complementary fringes, red and
yellow, being gradually lost in the white centre by a system
of mutual compensations. But if the field of view be broken
by the interposition of different objects, this mutual com-
pensation will be interrupted, and every interruption will
be marked w*ith complementary colours, which will be most
distinctly seen upon the edges of white objects ; where they
will be violet and blue on one side, and yellow and red on
the other.

These fringes are a necessary consequence of the diff'erent
refrangibility of light : the violet rays converge at a greater
angle than the green, and the green at a greater angle than
the red; of course, they arrive at a focus, so as to form
correct images, at different distances from the object glass.
Now, if it were possible to view these images through the
glass by which they are formed, or through any other similar
to it, and in the same direction, the images, notwithstanding
their different distances, would fall upon the retina together,
and form one correct picture, because these distances are
precisely what are required for this purpose ; the effect of
refraction, when the images fall on the eye, being in every
respect the reverse of what it is when they fall on a screen.
But when we view these images, as we necessarily do, in
an opposite direction, the eye glass, instead of correcting,
doubles the defect; the violet image, which, to produce
distinct vision of the whole, should be the nearest, is the
most distant ; and the red, which requires to be kept at a
greater distance to form a corresponding image with the
violet, is the nearest ; of course, the violet, which, after
passing the focus, is not only the most divergent, but de-
verges through a greater space, forms the largest image ;
the green, the next in size ; and the red, the smallest ; and
when these images are superposed, the different appear-
ances, as already described, are what our theory prepares us
to expect.

It appears, then, from these considerations, that the re-

2 A 2

356 P. C. on the Colours that enter into the [Nov.

medy for this evil may be applied either to the object glass,
or to the eye glass ; the images may be brought by the
former to positions which will enable us to view them dis-
tinctly with the latter ; or the latter may be so modified as
to enable us to see the images distinctly without this change
in their position ; and, of course, such remedies may be
applied to operate jointly.

Hitherto the attention of opticians has been chiefly
directed to the former remedy ; and it appears they have so
far succeeded, that the violet and the red images are united
in our present achromatic telescopes ; and as these two
colours form imaiges upon the retina which with the com-
mon telescope differ most in size, we may hope that, when
the attention of the artist is directed to a known object, the
apparently lesser difficulty presented by the green image
will not be long an obstacle to our bringing this noble
instrument to perfection. It appears, indeed, that this
desirable object has been already attained, by the ingenious
combination of a fluid with a solid to form the object lens ;
but, from the changeable character of fluids, a correction
by means of glasses only, is still a desideratum.

I have devoted considerable time and attention to the
class of coloured fringes connected with this subject, of
which I have not met with an explanation in any optical
work I have had an opportunity of consulting ; and as it is
desirable to form correct views of the principle upon which
they make their appearance, not only as it relates to the
subject we have adverted to, but, also, as it regards others
of almost equal importance, it is my intention to enter more
fully into their explanation than would be required to obtain
from them the evidence they furnish in support of my prin-
cipal object. I feel the more confident that a correct expla-
nation has not yet been given of these fringes ; because, it
necessarily implies a knowledge of the division of the spec-
trum, such as is here set forth ; for no other arrangement
will account, satisfactorily, for the different appearances
they present.

Newton has shewn that white light may be re-composed
by viewing the spectrum formed by a prism, through another
prism similar to it, and held at the same distance from the
spectrum, with its refracting angle in the same position.

1835.] Composition of White Light. 357

If the light be admitted through a small aperture to the first
prism, it is seen through the second prism in the position
which it would have occupied, and in every other respect
the same as if the light had passed directly from the aperture
to the screen, without the intervention of the two prisms.

The effect, therefore, of the interposition of a prism when
the light is suffered to fall directly upon the eye, is precisely
the reverse of what it is when the light falls upon a screen ;
for the violet light, which is the most elevated in the latter
case, is the most depressed in the former ; and, consequently,
the light, or the aperture by which it is admitted, being
viewed through a prism placed at the same distance from it
as the screen, will present a spectrum depressed instead of
elevated, and with the colours reversed : we see the light
in the direction in which it appears to come, which, of
course, is the reverse of that in which it is going.

If we increase the size of the aperture by which the white
light is admitted, the distance of the prism we view it with
must be increased in the same proportion, in order to pro-
duce the complete developement of its different colours ;
for each colour is seen under a certain angle of deviation
from the proper position of the aperture ; and it is the dif-
ference of these angles, which is constant with the same
prism, that causes the developement, or separation, of the
different images : the fringes, therefore, increase in breadth
by increasing the distance of the prism, until they are equal
to the breadth of the aperture ; when the images of it, and,
consequently, the colours, are seen completely developed.

Any objects which reflect white light may be substituted
for the apertures we have been speaking of; narrow strips
of white polished metal, when viewed with a prism, form
very distinct spectra : and when the metal does not exceed
the tenth of an inch in breadth, the three images of it may
be seen at a distance, which one hand can conveniently reach,
while the other supports the prism. The interposition of
the yellow glass reduces the colours of this spectrum to
green and red.

There can be no question with regard to spectra thus dis-
tinctly formed ; but when the colours of two or more of
these spectra run into each other, previous to their complete
developement, it requires some attention to form clear con-
ceptions of the different combinations produced by it.

358 P, C. on the Colours tliut enter into the [Nov.

If we direct a prism to a window, with the refracting
angle downward, the horizontal bars which separate the
panes of glass are seen fringed with colours; when the
prism is brought within a few inches of the window, the
colours above the bar are blue and violet, and below the bar
red and yellow ; the violet, though it appears upon the bar,
is seen, at this distance, separated from the red ; but upon
increasing the distance of the prism from the window, it
runs rapidly towards the red below the bar, and, by the
intersection of the two colours, forms a crimson. The
colours are now reduced to blue, crimson, and yellow, upon
the different bars of the window ; and between them the
white light appears to be admitted as usual.

But the white light thus admitted has very different pro-
perties to ordinary light, and corresponds in every respect
with the white light seen upon the screen, between the
fringes of colours, in an early stage of the developement of
the spectrum, when it is formed by the direct light of the
sun in the usual manner.

The shadows of all objects placed in this light, whether
before or behind the prism, are seen fringed with colours,
which increase in breadth with increase of distance, and
correspond exactly with the fringes seen upon the bars of
the window. This white light is refracted light : it pre-
serves its colour when uninterrupted, because the three
primitive coloui's intersect each other in the proportion
required to form white light ; but the rays of the three
colours have three different directions, or diverge at three
different angles, and the slightest interruption to the mutual
and successive compensation, which one image supplies to
the other, produces the appearance of colours.

If an object be placed in white light formed of parallel
rays,* its shadow makes its progress to a distant screen,
bounded by lines parallel to these rays ; and when it falls
upon the screen it forms an undivided shadow, without any
appearance of colours ; but refracted white light, being
formed by the intersection of three surfaces of parallel

• We are here speaking in general terms ; we know tliat it is impossible to
produce a surface of light formed of parallel rays ; every point of every object,
when illuminated with the direct light of the sun, receives rays from every part of
it : and the light reflected by the clouds must have still less pretension to this
character.

1835.] Composition of White Light. 359

rays,* of as many different colours making their progress
in three different directions, must ultimately produce, when
any part of it is intercepted, a distinct shadow of the inter-
cepting object in each colour : during its progress, how-
ever, and previous to the complete developement of the
different colours, the three shadows will remain united, and
exhibit, with a continually increasing breadth, a variety of
coloured fringes ; some of them simple, and others formed
by the intersection of two colours.

The action of the edges of the interposed bodies has
nothing to do with the production of this class of coloured
fringes : these edges act merely as boundaries, that allow
certain rays to pass, which, by their intersection at this
point, form white light ; hut which, in their further pro-
gress, require for this purpose a succession of other similar
rays ; and these being intercepted by the obstructing body,
they make their appearance in their proper colours, and in
their own independent direction. The fringes in refracted
white light, while they continue distinct, are violet and blue
on one side of the shadow, and yellow and red on the other ;
and by observing their progress, whatever may be their
breadth, we shall find that the two sides ar-e complementary
to each other ; so that if one were moved towards the other,
exactly the space occupied by the intercepting object, the
violet would fall upon the yellow, and the blue upon the
red, and again produce an uniform surface of white light.

The following simple experiment will prove this : Place
two white cards upon a black surface, with their edges
parallel, and about an inch from each other : upon viewing
the cards thus arranged, through a prism, with the refract-
ing angle downward, and held at a short distance from them,
the fringes upon the upper card will be blue and violet, and
upon thfe lower, red and yellow ; the distance of the prism
may be easily regulated so as to bring the violet of the
upper card close to the red of the under card, but without
interfering with it : if we now fix the prism in this position,
and with a pair of compasses, opened to the distance of the
cards from each other, measure the space from the centre
of the blue to the centre of the red, and from the centre of
the violet to the centre of the yellow, we shall find that the

\ See note p. 358.

360 P. C. on the Colours that enter into the [Nov

points of the compasses fall respectively on these centres ;
80 that, supposing the fringes to be fixed, and the cards
brought together, the complementary colours would be
superposed. That this superposition, or intersection, actu-
ally takes place, we may prove by bringing the two cards
so much nearer to each other as to cause a superposition of
the red and violet fringes ; this will reduce the separation
of the cards to about half their former distance : if we now
view the cards through the prism, we shall find that this
superposition has produced crimson, the colour formed by
violet and red, and that these two colours have disappeared.
If, pursuing the experiment, we gradually bring the cards
closer, as the blue covers the red, the violet will intersect
the yellow, and the whole of the colours will become weaker,
until, upon the meeting of the edges, they disappear.

In the closing part of this experiment, we separate the
violet from the red, and carry it forward to the yellow ;
while, with the same change in the position of the cards,
the blue is made to overlap the red, and the whole surface
becomes white. But, although in this experiment white
light is formed by the intersection of the usual complemen-
tary colours, it is worthy of remark, that the superposition
of the three compound colours which are here collected
together, viz. blue, yellow, and crimson, would also pro-
duce white light ; and it is desirable to notice it, not only
as a circumstance curious in itself, but, also, to prevent its
misleading those, who being disposed to consider blue, yel-
low, and red, the primitive colours, may suppose they have
formed white light by their superposition, simply by mis-
taking crimson for red ; a mistake which, as we have before
observed, may easily be made.

If we now confine our attention to one of these cards, we
may observe that the fringes upon the upper edge have the
same complementary character to the fringes upon the lower
edge ; and that, in fact, the whole of these fringes arise
from the want of a correct superposition of the three images
of the card upon the retina, produced by the unequal re-
fraction of the prism : we see the fringes upon the edges
only, because, upon every other part of the card white light
is formed by a system of mutual compensations.

If, instead of bringing the cards nearer to each other, we

]835.] Composition of White Light. 361

withdraw the prism to a greater distance from them, the
violet fringe will intersect the red fringe, producing by the
mixture the same crimson colour ; and after passing through
the red it will reach the yellow, its place in the red being
supplied by the blue, and the whole of the colours will gra-
dually disappear as before. If we recollect that the violet
light is turned out of its course more than the green, and
the green more than the red, we shall perceive that the
most refrangible colours must necessarily overtake, and
then intersect, the less refrangible ; and thus, not only fill
up the interval produced by the dark ground, but, also,
when the distance of the prism is sufficiently increased,
cause the disappearance of the complementary colours upon
its boundaries by their intersection.

It is thus that the crimson fringes are formed upon the
bars of a window when received through a prism ; and it
is upon this principle that these bars, and the fringes upon
them, disappear when the prism is withdrawn to a sufficient
distance.* The only difference in the two experiments is,
that when we look at the cards we see two distinct surfaces
of reflected light ; and when we look at the window we see
distinct surfaces of direct light : it is the intersection of the
spectra, formed by these distinct surfaces, which produce
the phenomena we have been investigating.

It is not necessary, in order to produce colours in white
refracted light, that the light of any part of the surface
should be entirely removed, the slightest inequality being
sufficient for this purpose ; for, to preserve an uniformly
white surface in refracted light, it is required that the rays
of any colour removed from one part, should be exactly re-
placed by rays of the same colour, and of the same intensity,
from another part ; which, in like manner, must be com-
pensated from another throughout the whole, in succession ;
but if the compensating rays, though of the same colour,
be of greater or less intensity, the colour in excess, in one
case, and the complementary colour in the other, will ap-
pear with an intensity proportioned to the difference. Per-
haps the description will be rendered more intelligible by

* By viewing a window (an open casement) at a distance of twenty or thirty
yards, the horizontal divisions are rendered invisible through an equi-angulai
prism.

362 P. C. on the Colours that enter into the [Nov,

stating, that the three surfaces of colours upon a white body
in their unrefracted state, are every wherein the proportion
which forms white light ; and though the quantity of light
may vary on different parts of the body, producing a diffe-
rence of intensity, every part has the essential properties of
white light ; but when the images are shifted by the action
of the prism, any difference in the intensity of the white
unrefracted surface must produce colours ; because the parts
of the images now intersect each other in different positions,
without any regard to the just proportion of the colours
which previously existed ; and as the whole of the colours
taken together are in the proportion which forms white
light, any excess in one part must be marked with a corre-
sponding deficiency in another. Hence, shadows, clouds,
and, in short, all obstructions, whether in reflected or direct
light, which produce inequalities in the light that falls
on the surface of the prism, are bounded with complemen-
tary colours.

The explanation of these fringes, which is here attempted,
introduces no new point of theory ; it is simply the applica-
tion of the Newtonian theory of refraction to particular cir-
cumstances ; the phenomena of which, though at first view
they appear to be out of its usual order, are, in fact, such
necessary consequences of it, that if the appearances were
not exactly as we find them, the theory, as delivered to us
by its illustrious author, could not be supported.

In a paper which I some time since addressed to the Royal
Society, I have extended the explanation to the fringes seen
in diffracted light; and, by showing the connexion be-
tween this light and refracted light, the most important, if
not the whole of the phenomena exhibited by the former,
are reduced to the most simple principles.

Having, thens, explained as well as I can, in so concise a
form, the nature and character of these fringes, with refe-
rence to the theory of three primitive colours, I will now
endeavour to draw from them more direct evidence in sup-
port of this theory.

If we look through a prism at the bars of a window, as
before directed ; at some little distance from the window,
the horizontal bar which divided the panes of glass will
appear to be fringed with three colours, blue, crimson and

1835.] Composition of White Light. 363

yellow ; if we then interpose the yellow glass, before spoken
of, between the eye and the prism, we shall find that the
crimson will be re-converted to red, and that the blue will
be changed to green. Now, having previously ascertained,
by a variety of experiments, that this crimson is formed by
the intersection of the violet and red fringes, we here per-
ceive that the very same action of the coloured glass which
restores the colour of the red, converts the blue to green.
The inference which must be drawn from this experiment,
that blue is a compound colour, does not admit of a doubt.

If the two surfaces of white light be separated by an object
of greater breadth than the window bars, the violet light
will be more distinctly seen before it intersects the red ;
and if in this state of the fringes we interpose the yellow
glass, the violet will disappear, and the blue will be con-
verted to green as before : it is therefore evident, from both
these experiments, that blue is a compound of green and
violet. By looking at distant objects, such as houses, trees,
&c., this sudden conversion, upon the interposition of the
yellow glass, is rendered very striking and beautiful.

The orange tint is given to yellow glass by its absorption,
in addition to nearly the whole of the violet, of a larger
proportion of the green than of the red light ; and, upon
this principle, by increasing the number of glasses, we may
convert the yellow fringes, together with the whole of the
white light, to a red. This experiment is not so striking
as the former ; because the absorbing power of the glass is
not so decided for green as for violet light ; but the prin-
ciple is the same, and it proves very clearly, that the same
action of the coloured glass which removes the green
fringes, converts the yellow to red.

With crimson glasses, the yellow fringes are converted
to a beautiful scarlet. The white light between the fringes,
when seen through this glass is crimson, or red and violet ;
but there being no violet in the yellow fringes, the red only
is admitted. The blue fringes are changed by crimson
glasses to violet, by the absorption of the green.

The experiments with these coloured fringes might be
varied so as to produce a body of evidence, which if it stood
alone would be sufficient to decide the question ; but in this,
as in other instances, I have produced such experiments

364 P. C. on the Colours that enter into the [Nov.

only as are necessary to explain the principles upon which
they are made, and applied ; leaving it to the judgment of
your readers to supply the deficiency, either to confirm or
to refute what I have advanced, as they may consider most
conducive to the discovery and support of truth, the great
objects of philosophical investigation.

I have found it very convenient, as well as instructive,
in many cases, to admit light through an aperture in a card,
of about a tenth of an inch in breadth, and about an inch in
length ; before which such coloured glasses may be placed
as are known to transmit only certain colours ; or other
glasses, the absorbing power of which it maybe desirable to
ascertain ; in order that the light transmitted by them may
be analyzed by the prism.

If we place an orange-yellow glass, of a tint just suffi-
ciently dark to prevent the transmission of any violet light,
between the window and the aperture in the card, the light
admitted by it will, of course, be yellow; but if a prism be
interposed between the aperture and the eye, the yellow
will Ibe divided into green and red, which, if the glass be
not of too dark a colour, will be nearly equal in breadth.
If we vary the experiment, by covering only a part of the
length of the aperture with the coloured glass, we shall
have a complete and simple analysis of white and yellow
light at one view.

I have formed another class of experiments, by causing
the prismatic fringes from a white card to fall upon a
coloured ground, and thus produce either white, or some
other compound colour. Upon a red ground, for instance,
such as scarlet moreen, when the reflection from the two
sources reach the eye in the proper proportions, the ground
becomes white where the blue fringes fall, and crimson with
the violet fringes.

The following simple experiment, upon this principle, is
very conclusive. I have a hearth rug the border of which
is formed of stripes of different colours, of about an inch in
breadth ; consisting of a black, a red, a light blue, a light
green, and a yellow, in the order in which they are named,
upon directing the prism to this border, the red retains its
proper colour ; the blue becomes green : and the green is
converted to blue ; the exchange of these colours is so com-

1835.] Composition of White Light. 365

plete that it can be observed only by their change of position :
when the violet fringe is extended to the yellow, by with-
drawing the prism, it converts it to white. In this experi-
ment there are no fringes from the black to interfere with
the red ; and the red being less refrangible than any part of
the blue, does not overtake it ; but the violet being more
refrangible than the green, with which it is combined to
form the blue, leaves it to form a union with the unmixd
green adjoining ; and, when still further extended, with
the yellow beyond it. By directing the prism across the
stripes diagonally, the breadth of the fringes may be regu-
lated without altering the distance of the prism.

In the multitude of experiments from which these have
been selected, I have never observed any thing which gave
me the least reason to doubt the correctness of the theory
by which I have attempted to explain them. The colours
which are considered compound have submitted to decompo-
sition, with the results which might have been expected,
whenever the proper methods for the purpose have been
adopted ; while the simple colours, red, green, and violet
have withstood every test which has been applied to them :
these colours may be weakened, or they may be wholly re-
moved in the course of our experiments, but they are never
changed. It is necessary to observe that we are here speak-
ing of the primary colours in a state of purity ; when they
are diluted with white light, the decomposition of this light
by coloured media, produces the appearance of modifications,
which however, are readily removed by such methods as
leave no doubt as to their cause.

P. C.
Weston Super Mare, August 31 st, 1835.
To the Editor of the Records of General Science,

Article IV.

The action of Saline Solutions on Fibrin. By Harry Rainy,
M.D., Lecturer on the Theory of Physic in the University
of Glasgow.

( To the Editor of the Records of General Science. J
Sir,

You will oblige me by giving the following remarks a
place in your Records of General Science. They were partly

366 Dr. Rainy on the Action of [Nov.

suggested by Professor Miiller's valuable paper on the Blood,
which appeared in one of your late Numbers.

I am, Sir,

Your Obedient Servant,

Harry Rainy.
Glasgow, \^th October, 1835.

Though it has been generally admitted that fibrin agrees
in its chemical properties with coagulated albumen, it has
been stated explicitly by Tiedeman and Gmelin, and more
recently by Miiller, that fibrin is distinguished by the pro-
perty of dissolving readily in a solution of muriate of am-
monia. Such authorities would seem to leave no doubt with
regard to the fact ; yet, on repeating the experiment fre-
quently some months ago, I did not observe any solution ;
and I have since noticed that Berzelius had been equally
unsuccessful. From these discrepancies it was obvious that
there must be some peculiarity either in the state of the
fibrin itself, or in the manner of conducting the process,
that materially influences the result.

My attention has recently been recalled to this subject by
accidentally observing that some fibrin prepared from
human blood, dissolved almost entirely in a solution o^ com-
mon salt, into which it had been put for the purpose of
preserving it in a moist state. I was led, by this circum-
stance, to perform the following experiments : —

1 . A portion of moist fibrin, recently prepared from human
blood, and very carefully washed, was put into a diluted
solution of common salt, at the ordinary temperature. It
gradually swelled, assumed a gelatinous appearance, and in
the course of twenty-four hours, dissolved in the liquid,
with the exception of a weak portion of a mucous-like sub-
stance, which formed a thin stratum at the bottom of the
phial, and which did not dissolve by adding fresh solution.

2. The solution of fibrin (1 .) was clear, and frothed readily
on agitation. When heated, it became opaque, and deposited
copious white coagula. This took place at 130° Fahren-
heit ; consequently, rather at a lower temperature than that
at which ordinary albumen coagulates. The precipitate did
not re-dissolve on cooling, and seemed, in every respect, to
agree in its properties with coagulated albumen.

3. It was natural to suspect, from the last experiment,

1835. Saline Solutions on Fibrin. S&f

that the fibrin would not dissolve in any solution of salt
heated to 130° or upwards. This conjecture was fully con-
firmed on trial. Fibrin put into solution of salt at any
temperature above 130°, did not dissolve, and could not
afterwards be dissolved, even at the ordinary temperature.
It is, therefore, evident that exposure to heat produces
some change on fibrin, which prevents its dissolving in solu-
tion of salt, exactly as heat renders ordinary albumen inso-
luble in water. This accounts for the failure of my first
trials with muriate of ammonia, for I had heated the solu-
tion with the view of accelerating the process ; and Berze-
lius appears to have operated in the same manner.

4. The portion of fibrin which dissolves bears a striking
analogy to soluble albumen. This led me to suspect that
its coagulation might be owing to some serum still adhering
to the fibrin ; but the same results were obtained however
carefully the fibrin was washed. And, on the other hand,
the fibrin, when kept in pure water, underwent no percep-
tible change, and the water did not extract from it any albu-
minous matter, for it remained perfectly transparent when
boiled. The presence of the salt, therefore, is necessary to
resolve the fibrin into the albuminous matter.

5. Some of the solution (1) was mixed with an aqueous
solution of corrosive sublimate. No precipitate was pro-
duced. I at first supposed that this indicated a decided
difference between soluble albumen and the substance which
the saline solution extracts from fibrin ; but, on making the
trial, I found that 'a solution of white of egg, mixed with
common salt, is not precipitated by corrosive sublimate.
This fact I now find had been previously noticed.

6. Some of the same fibrin, prepared from human blood,
carefully dried at the ordinary temperature, and which had
been kept in the dry state for several weeks, was acted on
by the solution of salt almost exactly as the recent moist
fibrin. It swelled, became white, then transparent and
gelatinous, and in a few hours dissolved, leaving a minute
quantity of whitish matter, which did not cohere like the
mucus left by the recent fibrin. The solution yielded copi-
ous coagula when heated, exactly like the solution of the
recent fibrin.

7. The solution of common salt employed in the above

368 Dr, Rainy on the Action of [Nov,

experiments was dilute. A saturated solution does not ap-
pear to have any effect in dissolving fibrin : but a mixture
of equal parts of saturated solution and water acts distinctly ;
and when the saturated solution is diluted with four or five
times its bulk of water, it acts still more rapidly. I have
not ascertained what degree of dilution produces the most
effective solutions, but a solution diluted with five times
its bulk of water, acts more powerfully than a stronger
solution.

8. From some trials I am inclined to think that by far
the greater part of the fibrin dissolved is coagulated and
precipitated by heat. When this is deposited the solution
still retains a minute portion of animal matter, apparently
similar to that which is extracted from fibrin by boiling it
in water.

9 . Solutions of muriate of ammonia, muriate of lime, muriate
ofharytes, nitrate of potash, sulphate of soda, tartrate of potash
and soda, and acetate of soda, have exactly the same effect
on the fibrin of human blood, that solution of muriate of
soda has. They dissolve by far the greater part of the
fibrin, leaving a slight residuum which is either of a mucous
consistence, or whitish, and without cohesion. The solution
coagulates about 130° Fahr., depositing white flocculi. In
like manner fibrin, if once heated to 130°, is not affected
by any of these solutions. It is very probable that many
of the salts which I have not tried produce similar effects.
Solutions of hydriodate of potash, and of subborate of soda,
dissolve the fibrin, but do not coagulate when heated. I
believe they prevent the coagulation of ordinary albumen.

10. The above experiments were made, as I have stated,
on fibrin of human blood. The experiments which I have
made on the fibrin oi ox blood, and sheep blood, have given
different results. Fibrin from these sources does, indeed,
yield some albuminous matter to the saline solutions, but it
is in small quantity. The fibrin retains its cohesion, and
the liquid only yields a slight muddiness, or, at most, a very
few flocculi when boiled. The solutions of muriate of am-
monia, common salt, nitre, and sulphate of soda, appear to
be the most effective.

11. I have made some experiments on the action of some
of these solutions, on muscular fibre, freed as much as pos-

1835.] Saline Solutions on Fibrin.

sible from cellular membrane, and carefully washed. In no
case was the muscular fibre completely dissolved, or even
so much changed as to destroy its fibrous appearance, when
viewed with the microscope ; but, in general, the muscular
matter was softened, and the liquid gave more or less albu-
minous precipitate when boiled. These effects were most
distinct with human muscle, less so with the muscle of
haddock, very slight with the muscle of ox, and scarcely
perceptible with the muscle of sheep.

12. It follows, from these facts, that fibrin, diff'ers mate-
rially in its properties, according to the source from which
it is derived ; that in general it yields to saline solutions,
at the ordinary temperature^ a substance resembling soluble
albumen ; that the proportion of this substance yielded by
fibrin varies materially ; that it is greatest in the fibrin of
human blood ; that fibrin cannot dissolve in solutions of
muriate of ammonia if heated above 130°; and that several
kinds of fibrin are very slightly acted on by that solution at
any temperature.

Article V.

On the Sesquisulphate of Manganese. By Thomas Thomson,
M.D., F.R.S., (fee, Regius Professor of Chemistry in the
University of Glasgow.

When neutral solutions of sulphate of zinc and chloride of
manganese are mixed together, no sensible change takes
place. But if the mixture be concentrated it gradually
deposits yellowish-white coloured crusts, which constitute
a hitherto undescribed salt of manganese.

This salt dissolves readily in water, but I could not suc-
ceed in obtaining it in crystals. Its taste is sweetish and
astringent, and slightly acid.

16'26 grs. of it, rendered as dry as possible by pressure
between the folds of bloating paper, and subsequent expo-
sure to a gentle heat, ^^ ere dissolved in water and mixed
with a great excess of carbonate of ammonia. The mixture
was left for twenty-four hours, and during that time was
frequently agitated. It was then thrown on a filter, to
collect the white precipitate which had fallen. This preci-

VOL. II. 2 B

3^6 Dr. Thomas Thomsoji on the [Nov.

pitate became brown by exposure to the air, and by ignition
acquired a reddish tint. In this state it was red oxide of
manganese. It weighed 5*78 grs. = 5-38 gr. of protoxide
of manganese.

The ammoniacal liquid which passed through the filter
being evaporated to dryness, and the residue re-dissolved
in water, left a small quantity of matter, which became red
by ignition, and was also red oxide of manganese. It
weighed 0*07 gr. = 0*065 gr. of protoxide. So that the
whole protoxide of manganese contained in 16*26 grs. of
the salt amounts to 5*445 gr.

The liquid thus freed from base was treated with nitrate
of silver. The chloride of silver obtained, weighed after
ignition, 0*5 gr. = 0*12 gr. of chlorine.

The excess of silver being removed by the addition of a
little common salt, the liquid was precipitated by muriate
of barytes. The sulphate of barytes obtained being collected,
washed and ignited, weighed 24*06 grs. = 8*5 gr. sulphuric
acid.

What is wanting to complete the 16*26 grs. must be water.
For no other constituent could be obtained.
Thus, it appears that the salt is composed of,

Sulphuric acid 8*5

Chlorine 0*12

Protoxide of manganese . . 5*445
Water 2*195

16*26
The chlorine was doubtless combined with manganese,
probably in the state of tris-chloride. We must, therefore,
subtract 0*36 from the protoxide of manganese. The re-
mainder, 5*085, is the quantity of manganese in combina-
tion with the sulphuric acid. Now, 5*1 is to 8*5 as 4*5 to
7*5. So that the salt is composed very nearly of

IJ atom sulphuric acid . . 7*5

1 atom protoxide of manganese 4*5

2 atoms water 2*25

14*25
The water was rather less than two atoms. Probably a
little had been driven off in the attempt to dry the salt by
heat.

1835. Sesquisulphata of Manganese. 371

To what the yellow colour is owing, which this salt pos-
sesses I do not know. The solution of it in water is colour-
less, so that none of the manganese can be in the state of
red oxide. I could detect no oxide of zinc in the oxide of
manganese, and none could be extracted by digesting the
newly precipitated oxide in caustic potash.

Article VI.

Animal Heat.

Becquerel and Breschet are at present engaged in a series
of experiments upon this subject. Their mode of deter-
mining the temperature of different parts of animal bodies
is by means of a thermo-electric multiplier, with needles
and probes formed of two different metals, soldered in cer-
tain^ points only.

The needles are of two kinds, the most simple being com-
posed of two other needles, the one of platinum, or copper,
the other of steel, soldered at one of their extremities in
the direction of their lengths, each of them being about half
a millimetre (0*0196 inch) in diameter, and a decimetre
(3*93 inches) in length. One of these needles is introduced
into that part of the body whose temperature is to be deter-
mined, the soldered part being placed in the same medium.
The two free ends are then made to communicate with the
wires of the multiplier. The points of junction, platinum
and copper, steel and copper, if the platinum and steel needle
is employed, or the points of junction of steel and copper,
if the steel and copper needle is employed, are placed in
melting ice, in order that the temperature may remain con-
stant. The magnetic needle then deviates, in consequence
of the difference of temperature which exists between the
point examined and zero. Experience shows that the maxi-
mum effect is found between 0° & 25° ; therefore, before
commencing the experiment, the multiplier may be so
adjusted that the needle shall stand between 20° &: 25°, in
order that the most minute deviations may be noted. When
the magnetic needle has acquired a fixed equilibrium, the
probe is withdrawn from the part examined, and the corre-
sponding soldered part is plunged into a water-bath, of
which the temperature is raised until a deviation is pro-

2 B 2

372

Animal Heat.

[Nov.

duced, considerably, above that which was previously ob-
tained. The water is allowed to cool, and the temperature
corresponding to this deviation is marked by an excellent
thermometer. By this method of procedure the following
temperatures were obtained. A &: B distinguish two per-
sons aged 20 years ; C, a person aged 55 years : —

First series of Experiments. — Temperature of the Air 53°- 6

NAME OF THE PART.

TEMPERATURE.

Brachial biceps of A

. 97°75F.

Adjacent cellular tissue

94-46

Mouth .....

. 98-24

Brachial biceps of B .

98-29

Abjacent cellular tissue

. 95-81

Mouth

98-06

Biceps of B' . ...

. 98-18

Cellular tissue ...

95-59

Mouth

. 98-6

Black Dog.

Flexor Muscle of the thigh

. 101-12

Cellular tissue of the neck .

. 98-6

Abdomen . . ,

. 101-3

Chest

. 101-12

Another Dog.

Muscle of the thigh

. 100-4

Chest

. 98-6

Abdomen ....

. 100-58

Second series of Experiments, — Temperature of the Air 53*6

Biceps of B .

. 98-29

Cellular tissue

9604

Calf of the leg.

. 98-42

Mouth

98-6

Biceps of C .

. 98-42

Cellular tissue

95-59

Third Experiment. — Black Dog already submitted to

Experiment,

Muscle of the thigh . . . 101-48

1835.]

Animal Heat.

37;

Third series of Experiments.

NAME OF THE PART.

TEMPERATURE.

Mouth of B .

. 98°-33

Mouth of A

98-51

Mouth of B by thermometer

. 98-6

Second Experiment,

Biceps of B .

. 98-78

Cellular tissue ....

95-86

Third Experiment. — Carp (Cyprinus Carpio.)

Different parts 56*3

Water 554

Fourth series of Experiments. — Made with probes with two
branches, termed needles of the second kind.

Biceps of B . . . 1-181 inch deep 98*15

Muscles of the calf . 1*572 „ 98*15

Adjacentcellular tissue 0*393 ,, 94*1

Pectoralis major . . 1-572 ,, 98*15

Adjacent cellular tissue 0*393 ,, 94*1

Second Experiment, — A young Griffin of medium size.

Pectoralis major . . 1*572 inch deep 100*85
Cellular tissue . . . 0*393 „ 99*5

Third Experiment upon B.

Biceps at .... 1*18 inch deep 97*7
Cellular tissue . . 94* 1

Fourth Experiment y — Upon a Dog.

Muscle of the thigh . . . 101-3

Cellular tissue of the thigh . . , 100-31

The lung 101*3

Abdomen 101 3

Fifth series of Experiments, with two Multipliers. — A Dog.
Muscle of the thigh . • . 100*85

Chest 101*9

Brain (The two ends of the probe
were admitted by trepanning a
small portion.) . . . 100*85

374 Pyroxylic Spirit audits Compounds. [Nov.

From these experiments it appears that, 1 . In man the
temperature of the muscles exceeds that of the cellular
tissue by 4° & 2°i. 2. The mean temperature of the muscles
of three young persons, aged 20 years, was found to be
98°* 186. With the common thermometer. Dr. Davy esti-
mated the heat of the human body at 98° ; and Despretz
found the mean temperature of nine men, aged 30 years,
98°-85; of four men, aged 68, 98°-83 ; of four men, aged
18 years, 98*58. While John Hunter found the tempera-
ture of the rectum of a healthy man between 97° k 98°.

3. The mean temperature of the muscles of several dogs
is 100*94 ; while Despretz makes it 103°*06. This difference
may be attributed to accidental circumstances. It is to be
observed, also, that the state of the health has an effect
upon the temperature. The temperature of the brain was
100*85 : this temperature was suddenly reduced some de-
grees, and in a few minutes the animal died.

4. The temperature of the common carp was only about
^■Q of a degree above that of water.

5. The contraction of the muscles augments the tempera-
ture, while the compression of an artery diminishes the
temperature. Agitation, motion, and in general every
thing which determines a flow of blood, tends to elevate the
temperature. Whether the nervous system has any share
in producing a rise of temperature remains to be deter-
mined.*

Article VII.

Pyroxylic Spirit and its Compounds.

Dumas and Peligot have published an elaborate examination
of pyroxylic spirit, (Ann. de Chim. Iviii. 1.) which will be
found interesting to British chemists, as this substance is
becoming a very important article in the laboratory. It
was discovered by Philip Taylor, in 1812, who termed it
pyroligneous ether, from the mode in which it is prepared.
The lowest sp. gr. to which, as far as we are aware, it has

• Ann. deChim. et de Phys. lix. 113. (It is to be regretted that the authors
do not mention the season of the year when these experiments were made ; for, as
has been remarked to me, by a distinguished comparative anatomist, the relative
temperatures of fishes, and the medium in which they are placed, vary according
to the season. — Edit.)

1835.] Pyroxylic Spirit and its Compounds, 376

been brought in this country, is -812. Dumas, however,
states that its density at the temperature of 68° is '798, and
that of its vapour 1*120. Its boiling point, according to the
same authority, is 151°|,at a pressure of 30 inches.

1 . Pyroxylic Spirit, or Hydrate of Carhydroyen. — For the
purpose of analysis, the pyroxylic spirit was rectified with
lime newly burned, and lastly distilled with mercury in a
retort supplied with a thermometer which indicated the
temperature 151°, from the beginning to the end of the
process. Its composition was found to be, carbon, 37*7;
hydrogen, 12*5 ; oxygen, 49- 8. This agrees very nearly,
taking into consideration the sp. gr., with

1 vol carbon . . . = '4166 = 1 atom . . . -75

2 vols, hydrogen . -1388 2 atoms . . -25
\ vol oxygen . . . '5555 1 atom ... 1*

Mill 200

Hence, this substance is a hydrate of carbydrogen, CH -f
HO. Dumas has, unnecessarily, coined a new name to
distinguish this base, viz. Methylene, (from ^Sv wine, and
v\y] wood). What advantage is gained by this innovation it is
difficult even to guess at. The disadvantages of designating
simple compounds by arbitrary names (since this compound
turns out to be one of the simplest organic compounds with
which we are acquainted) are sufficiently obvious, and we
trust that this name will not be adopted by British chemists.
The existence of this simple compound of hydrogen and
carbon in pyroxylic spirit was demonstrated in 1826 by Dr.
Thomson. (Edin. Trans, xi. 15. Inorganic Chemistry, i.
194, ii. 294.) It is difficult to allow ourselves to suspect
that Dumas should have been ignorant of this fact, which
has been published for nine years, but in consequence of
the absence of any allusion to it, it is impossible, in charity,
to avoid drawing such a conclusion. Dr. Thomson ob-
tained the compound of 1 atom carbon + 1 atom hydrogen
the basis of pyroxylic spirit, according to Dumas, by mixing
3 parts of muriatic acid, 1 part nitric acid, and 1 of pyroxylic
spirit, applying heat, and receiving the gas disengaged over
mercury. The product was, a mixture of a new inflammable
gas 29 parts, deutoxide of azote 63, azote 8.

The new gas was composed of 1 vol. carbon, 1 vol.

376 Pyi'oxylic Spirit and its Compounds. [Nov.

hydrogen, and IJ chlorine, containing half an atom more
chlorine than the chlorhydrate of methylene of Dumas,
tvhich was prepared by heating a mixture of 2 parts of
common salt, 1 part of pyroxylic spirit, and 3 parts of con-
centrated sulphuric acid.

2. Dihydrate of Carhydrogen. — If 1 part of pyroxylic
spirit be distilled with 4 parts of sulphuric acid, a similar
appearance is presented as when alcohol and concentrated
sulphuric acid are distilled. During the whole process
much gas passes over, containing sulphurous and carbonic
acids, which may be removed by caustic-potash. A gas then
remains, which is absorbed by water, possesses an ethereal
odour, and burns with a flame like that of alcohol. It is a
dihydrate of carhydrogen, or the hydrate of methylene of
Dumas, and bears the same relation to pyroxylic spirit that
ether does to alcohol. It required 3 vols, oxygen to burn
it. Its density, by experiment, was 1*617, which corre-
sponds nearly with,

2 vols, carbon . . . . = -8332 = 2 atoms . . 1*5
2 vols, hydrogen . . . -1389 2 atoms . . -25
1 vol. vapour of water . '6250 1 atom . . 1*125

1*5972 2*875

Hence, its composition is exactly the same as alcohol, in
so far as regards the proportions of the elements ; but it is
obvious, from the difference in their properties, that the
elements are differently arranged, the dihydrate of carhy-
drogen being 2 C H + HO.

The dihydrate is a colourless gas, with an ethereal smell,
and does not liquify when cooled to — 16° (3°i F.) Water
dissolves about 37 times its volume at the temperature of
18'^(64°J), and acquires a smell of ether, and a taste of
pepper. Alcohol dissolves it in greater quantity. Sulphuric
acid dissolves much of it, and abandons it when diluted
with water. It is but justice to state that Macaire and
Marcet discovered this gas. It is always a subject of regret
to see one man undervaluing the labours of another. Dumas
and Peligot have, in the present and preceding instances,
by omitting to state the experiments of their predecessors,
Ijiid themselves open to this charge. We are willing to
believe that it is a fault of omisssion, rather than of com-

1835.] Pyroxylic Spirits and its Compounds. 377

mission, proceeding from their ignorance of the experiments
referred to.

3. Hydro-chlorate of Carbydrogen, or of methylene, ac-
cording to Dumas, is prepared by heating a mixture of 2
parts of common sali^ 1 part of pyroxylic spirt, and 3 parts
of concentrated sulphuric acid. A gas comes over which
may be collected over water. It is a neutral body. It
is colourless, smells of ether, with a sweet taste ; burns with
a white flame, having green edges. Water absorbs 2*8
times its volume at the temperature of 61°. It does not
liquify at zero. Its density is 1*736. Hence, its composi-
tion is, 1 atom carbydrogen . . '4860 '875
1 atom hydrochloric acid 1*2847 4*625

1*7707 5-500
Its formula is therefore CH, + Ch H. This gas is de-
composed into hydrochloric acid and carbydrogen by a red
heat.

4. Hydriodate of Carbydrogen^ is formed by distilling 1
part of phosphorus, 8 parts of iodine, and 12 or 15 pyroxylic
spirit. The iodine is to be dissolved in the pyroxylic spirit,
the solution placed in a retort, and the phosphorus added
gradually; a lively action ensues. When it has subsided the
rest of the phosphorus is added, and the mixture distilled.
An ether passes over, consisting of pyroxylic spirit and
hydriodate of carbydrogen. The latter is separated by the
addition of water, which immediately precipitates it. This
hydriodate is still impure, and requires to be distilled over
an excess of chloride of calcium and massicot, in a water-
bath. When pure it is colourless; slightly combustible,
sp. gr. 2*237 at 71 J°. Boils at 104° or 122°. The density
of its vapour is 4*883 by experiment. Hence, it consists of
1 vol. hydriodic acid . . 4*4097
1 ,, carbydrogen . . . '4860

4*8957
5. Sulphate of Carbydrogen, an oily substance produced
by distilling 1 part of pyroxylic spirit with 8 or 10 parts of
concentrated sulphuric acid. It is separated by decantation
from the liquid with which it is mixed. It is then agitated
with a little water, to separate sulphuric acid, then with
chloride of calcium, to remove the water, and is afterwards

378 Pyroxy lie Spirit and its Compounds » [Nov.

rectified with caustic-barytes, to get rid of sulphurous acid.
Lastly, it is kept for some time in a vacuum with concen-
trated sulphuric acid and potash. It possesses a smell of
garlic. Sp. gr. 1-324. Boiling point 71° J. The density
of its vapour is 4*565. It consists of CH -f SO^ +H O.
Its atomic weight is, therefore, 7*

6. Nitrate of Carbydrogen, may be obtained by distilling
50 parts of nitrate of potash, 50 of pyroxylic spirit, and 100
sulphuric acid. A thick and colourless ether remains at
the bottom, which must be separated from that which swims
over it, by decantation and distillation several times, with a
mixture of massicot and chloride of calcium. Even yet it
is not pure, for a portion of it boils at 140°. When the
temperature rises to 150° the remainder is nitrate of carby-
drogen. It burns with a yellow flame. Sp. gr. 1-182.
When heated in a tube it detonates violently, which renders
it difficult to analyze it. It is easy to see the cause of
this, because it contains nitric acid, hydrogen, and carbon,
like gunpowder. The density of its vapour is 2-640. Its
composition is probably Az O^ 4- CH.

7. Oxalate of Carhydrogen is obtained by distilling equal
parts of sulphuric acid, oxalic acid, and pyroxylic spirit.
A liquid is procured which, in the air, crystallizes in rhom-
boidal plates. When the distillation has terminated, the
retort is cooled, and 1 part of pyroxylic spirit is added, and
distillation performed again with the same results. The
crystals are laid on filtering paper, purified by fusion in an
oil bath, and distilled over massicot, to deprive them of
oxalic acid. They fuse at 124°. Oxalate of carhydrogen
dissolves in cold water. It dissolves in alcohol and py-
roxylic spirit. Ammonia changes it into oxamide. It con-
sists of CH 4- C2 03 + Aq.

8. Acetate of Carhydrogen, may be readily procured by
distilling 2 parts of pyroxylic spirit with 1 part of crystal-
lizable acetic acid, and 1 part of common sulphuric acid.
The product is agitated with chloride of calcium which
separates an ether containing much acetate of carhydrogen.
A little sulphurous acid and pyroxylic spirit remain, which
may be removed by agitation with caustic lime, and digestion
for 24 hours with chloride of calcium. The density of its
vapour is 2-563. It consists of C H -|- C* H^ O^ -f H O.
It boils at 136^i. Its density is -919.

1835.] Pyroxylic Spirit and its Compounds. 379

9. Formate of Carhydrogen, — This ether was prepared by
distilling a mixture of equal weights of sulphate of carby-
drogen and formate of soda. The product is distilled over
a new portion of formate of soda, and lastly, in a retort from
a water-bath. Its formula is C H + C^ H O^ + HO. The
density of its vapour is 2*4.

10. Benzoate of Carhydrogen is formed by the distillation
oi 2 parts benzoic acid, 2 sulphuric acid, and 1 part py-
roxylic spirit, and precipitating the product by water. By re-
distilling the residue of the first operation with new portions
of pyroxylic spirit, more benzoate of carhydrogen passes over.
The product, after precipitation by water, should be agitated
with chloride of calcium, decanted and distilled over dry
massicot. It is then to be boiled till the temperature
remains fixed about 388°. It is oily, colourless. Sp. gr,
1*10. The density of the vapour is 4*717. It consists of
C H + Ci5 H6 03 + H O, or 1 atom of each of the
ingredients.

11. Chloro-carhonate of Carhydrogen, When pyroxylic
spirit is admitted into a vessel containing chloro-carbonic
acid, muriatic acid and chloro-carbonate of carhydrogen are
formed. The latter separates in the form of a heavy oil.
Its precipitation is secured by the addition of water. It is
then decanted, rectified with a great excess of chloride of
calcium and massicot. It is a colourless liquid, very vola-
tile, with a penetrating odour. It burns with a green flame.
It consists of 1 atom of acid and 1 of base.

12. Sulpho-carbydrogic Acid can be formed by the action
of sulphuric acid and pyroxylic spirit, but more readily by
dissolving the double sulphate of carhydrogen in water,
precipitating the barytes by sulphuric acid, and crystallizing
the liquid in a vacuum. The crystals are white needles.
It is strongly acid, and forms salts with all the bases.

Sulpho-carhydrogate of Barytes is prepared by adding
gradually 1 part of pyroxylic spirit to 2 parts concentrated
sulphuric acid ; much heat is extricated. The liquid, after
the cessation of action, is diluted with water, and super-
saturated slightly with barytes.

The liquid is then submitted to the action of carbonic acid,
and again filtered. Sulpho-carbydrogate of barytes remains
in a pure and neutral state. By careful evaporation it is
obtained in the form of beautiful square plates. The salt is

380 Analysis of Opium. [Nov.

colourless, and effloresces in the air. When strongly heated
it is decomposed, and sulphate of barytes remains.

The salt of lime is deliquescent. That of potash cry-
stallizes in pearly plates.

13. Ammonia Sulphate of Carhydrogen, or sulpho-methy-
lene of Dumas is formed by passing a current of dry am-
monia over sulphate of carbydrogen. A soft crystalline
mass is formed. It may be also procured by th« action of
liquid ammonia upon sulphate of carbydrogen. The liquid
which remains after the re-action, when evaporated in
vacuo, furnishes beautiful crystals, whose composition is
exactly represented by an atom of anhydrous sulphate of
carbydrogen, united to an atom of anhydrous sulphate of
ammonia.

14. Ammonia with Oxalate of Carbydrogen, or Oxamethy-
lane of Dumas, is produced when a current of dry ammo-
niacal gas is passed over oxalate of carbydrogen. A white
crystalline mass is formed, when dissolved in alcohol ; cubic
crystals are obtained by evaporation. In order to under-
stand its composition, we have only to admit that pyroxylic
spirit is produced during the action, 2 atoms oxalate of
carbydrogen, and 1 ammonia being converted into an atom
of oxamethylane, and 1 of pyroxylic spirit.

15. Urethylane is the name given to the product of the
action of chloro-carbonate of carbydrogen with ammonia ;
much sal-ammoniac is formed, and a deliquescent sub-
stance crystallizing in needles.

In remarking upon these compounds, Dumas observes,
that di-hydrate of carbydrogen is isomeric with alcohol ;
Bicarbonate of carbydrogen with citric or malic acid;
Oxalate of carbydrogen with succinic acid ; Formate of
carbydrogen with acetic acid ; Acetate of carbydrogen with
formic ether ; Citrate of carbydrogen with anhydrous
sugar.

Article VIIL
Analysis of Opium.*

CouERBE gives the following method for analyzing this
complicated substance, as proposed by Gregory :

• Ana. de Chimie, lix. 151.

1836.] Analysis of Opium. 381

The opium is first taken up by cold water, and then con-
centrated, chloride of calcium is added to the solution, in
the proportion of 2 ounces to the pound of opium. It is
then boiled and allowed to crystallize. When the whole
has become solid, the crj^stals are submitted to pressure.
The crystals contain Codeine and Morphine united to muri-
atic acid.

The liquid portion which possesses a very black colour,
with the consistence of syrup, contains, Bimeconate of Zzwe,
pure Morphine, Narceine, Thehaine, Meconine, pure Narco-
tine. In order to separate these substances, the liquid is
brought to the consistence of molasses, and in order to free
it from an immense quantity of a peculiar black substance,
which is improperly termed fat, it is diluted with water
acidulated with muriatic acid. The addition of the acid
causes this matter to swim on the surface ; it is then
skimmed off; it contains much ulmine. Ammonia is next
poured into the purified liquid, by which means. Morphine
and Thebaine are precipitated. This deposit is dried, pul-
verized and treated with boiling ether. The Thebaine
though little soluble in this liquid, dissolves. The ethereal
solution is distilled when the Thebaine remains behind in
the form of small reddish crystals. These are purified by
dissolving them in alcohol, and by animal charcoal ; lastly,
in order to have it perfectly pure, it should be dissolved in
ether and evaporated spontaneously.

The ammoniacal liquid is concentrated to the consistence
of liquid honey, and agitated strongly with ether. This
liquid dissolves the Meconine. By distilling the ether this
substance remains ; it is purified by solution in water and
charcoal, and when the aqueous solution is evaporated,
white crystals of long prismatic needles make their appear-
ance.

When we wish to obtain the other substances, all these
processes are not necessary, it is sufficient after having
precipitated the infusion of opium by muriate of lime, to
concentrate the liquid and treat it directly with ether. By
this means, rather more meconine is obtained. When the
ether has ceased to act, the black liquid thus taken up is
decanted and exposed in a cool place where it assumes a
crystalline form ; it is then expressed and treated with

382 Analysis of Opium. [Nov.

boiling alcohol. The product dissolved in this case is
Narceine. But it is proper to state, that as this substance
is not soluble in ether, and as the black substances which
accompany it are soluble in alcohol, there are some diffi-
culties accompanying the process for obtaining it; it is
always procured pure by employing boiling water. No
notice is here taken of meconic acid, which combines with
the lime, and forms bimeconate of lime, because Robiquethas
sufficiently explained the method of obtaining it.

With regard to the double muriate of morphine and
codeine, it is dissolved several times in boiling water,
passing it through charcoal in order to decolourize it, or
decomposing it by ammonia, which precipitates almost all
the morphine, and leaves in the solution the codeine, with a
little morphine combined with the muriatic acid, consti-
tuting the salt of Gregory. The morphine is purified by
the usual means.

The solution of the triple salt is evaporated until it appears
about to crystallize ; then caustic potash is added in excess,
which precipitates the codeine and retains the morphine in
solution ; the solution is then heated slightly, and allowed
to stand for a day. The codeine, which at first appeared
as an oil, crystallizes. It may be purified by solution in
ether or alcohol. The former is preferable; because, if it
contains morphine, this will be a direct method of sepa-
rating it. From 40 lbs. of opium Couerbe obtained by this
process,

1 oz. of meconine
IJ ,, codeine
f ,, narceine
1 ,, thebaine
50 ,, morphine
He did not extract narcotine, which exists in the refuse of
opium and is well known. These substances present the
following appearances when agitated with sulphuric acid
containing a little nitric acid. Morphine gives a brownish
colour. Codeine, a green colour. Thebaine a yellow rose-
colour. Narcotine, a blood-red colour. Meconine, a tur-
meric yellow, then a red colour. Narceine, a chocolate
colour.

Thebaine crystallizes from an ethereal solution, in flat

1835.] Analyses of Books. 383

rhomboidal prisms, with a fine lustre, and white colour.
It is strongly alkaline.

When exposed to the temperature of 266° it fuses, and
becomes solid at 230°. Narcotine fuses at 338°, and solidi-
fies at 266°. Codeine fuses at 302, and meconine at 194°.

The strong acids convert thebaine into resin, and when
diluted form crystallizable salts. The following results
were obtained by Couerbe : —

Carbon. Oxygen.
Narceine . . 56-818 - 31-900
Thebaine . . 71-976 - 15-279
Codeine . . 72-846 - 14-775

The paramorphine of Pelletier was obtained by Thibou-
mery by treating the infusion of opium with slacked lime.
He obtained by this means a clear liquid, and a precipitate
containing much lime, which was treated with alcohol, and
the solution gave, instead of morphine, this new substance,
which appears the same as the thebaine of Couerbe.

The proportion of morphine in opium, Couerbe states may
be determined in the course of two hours, by boiling the
infusion of opium with an excess of lime, and passing the
solution through a filter. If an acid be added, taking care
not to add it in excess, the morphine precipitates.

Hydrogen.

Azote.

- 6-626 -

4-656

- 6-460 -

6-385

- 7-148 -

5-231

Article IX.

ANALYSES OF BOOKS.

I. — Poggendorff's Annalen der Physik und Chemie,
Band, xxxiv. 1835.

Description of a Barometer, by C. Brunner of Bern.

The author observes that the atmospherical pressure may be
measured in two different ways, either by observing the height of a
hquid column contained in a tube, the upper part of which is deprived
of air, and the lower extremity is exposed to the excess of the atmos-i
phere, as in the common barometer, or by the volume which a gas
occupies in a closed vessel, when the latter is completely elastic, or
the act of enclosing the gas in the vessel is effected without percep-
tible resistance.

The apparatus of Varignon, described in 1705 ; the sympiesometer
of Adie the baroskope of Prechtl, and the differential barometer
of August, are examples of the latter. He then proceeds to describe

384 Analyses of Boohs. [Nov.

an instrument which he has constructed upon similar principles, and
which may be termed the volume barometer. The peculiarities of
his contrivance depend upon having the surface of the liquid in the
tube, and that surrounding it, on a level : that the liquid shall be of
such a nature as to have no perceptible tension at common tempera-
tures : that it shall not perceptibly adhere to the glass, lest a portion
remain hanging in the tube, and the enclosed volume of air be under-
valued : that all the observations be taken at the same temperature,
or that the influence of the temperature upon the enclosed air be
taken into account.

He recommends it as being very convenient for making the neces-
sary reductions for gas mixtures.

On altitude barometers of the most complete construction, by
George Breithaupt, of Cassel.

The writer states that he has devoted much time to the perfecting
of these important instruments. He describes his precautions for
purifying the mercury, which he prepares from cinnabar, by distilla-
tion with lime. It is then strained through card paper many times,
heated nearly to the boiling point, and filtered into the tube. The
nonius scale he forms of the most delicate kind, extending to j^
millimetre and ^^ line and adjusts a microscope to it.

Description of an apparatus for assaying silver, in the wet
wa'jy by E. Jordan, of Cassel. This is somewhat similar to the
apparatus described by Gay Lussac, in his work upon the assay of
silver. It differs in this respect, however, that by the proceeding of
Jordan the contents of an alloy are determined in the direct way.

Observations on the declination and daily variation of the
needle at Pekin, 6y Hr Kowanko, member of the Imperial Rus-
sian Mission at Pekin, communicated by A. T. Kupffer. The
observations were made with Gambey's declination compass. The
westerly declination was found to be for March 1832, 2" 15' 42".
The westerly progress of the needle from December 1831 to March
1832, was 12'. At Petersburgh, during the same time, the easterly
deviation was 3', where the total deviation was on the 22d and
23d December,' 60 27' 5", and on the 20th and 2 1st March, 6^ 23'
58". Hrn. G. Fuss, who preceded Kowanko at Pekin, found the
declination there in December 1830, 1° 38' W, in May 1831, 1° 55' W,
and in June 1831, !« 48' W.

The needle reached its easterly variation on 21 st December at 9 a.m.
On 22d December at 10 a.m. On 20th March at 9 a.m. , and on 21st
March at 9 a.m. While its westerly daily variation was as follows :
21st December, 2 p.m. var'=:4' 10' 22d December 2 p.m. var. =2'
20th March . 2 p.m. var. =5' 41" 21st March . 2 p.m. var. =6'

Magnetical Observations at Nertschinsk, communicated by
A. T. Kupffer. — Cancrin found the inclination of the needle at this
place, on the 5th August 1832, at 10 a.m. GQ'* 33 4'. The declina-
tion on 5th August, 2 to 4 p.m., was 4° 14 15" W. 22d September
4o7 43 W.

On the Magnetism of the Earth, by Prof. L. Moser, of Konigs-
berg. lu a previous paper, Moser endeavoured to prove, from vari-

1835.] Poggendorff^s Annalen dei" Physik, ^c.

385

ous data, that the magnetic intensity of the earth is situated on its
surface. He follows up the subject in the present paper. He con-
siders as demonstrated, that the magnetic distribution over the earth
is proportional to the line of its breadth, and calculates the inclination
and intensity. He also discusses the theoretical grounds from which
the temperature of the earth has been calculated Ipy mathematicians.
He calculates the intensity to be in 54o 42' 50 ' N. L., 1 -6937, and
the inclination ']\o 8' 20 . The mean temperature of the northern
hemisphere he finds 15° R. (nr)«|) in the 30th" of latitude. That of
the southern hemisphere is 63o*34.

Mas:netic iiijluence produced by the Electrical Machine. — M.
Llambias, of Port Mahon, in a communication to the Academy of
Paris, observes that magnetism can be developed in this way. The
two electrical currents in a metallic conductor discharged from a
Leyden jar, may be separated, at least, in part, by having the con-
ductor adjusted so as to separate into two or more arms, and by
having an interruption in one of these arms, which gives origin to a
spark in any arc or part of the same, where the two currents unite in
passing through ; it is in general the positive stream (that proceeding
from the positive to the negative pole) which contracts the power of
communicating the magnetic influence.

List of earthquakes^ volcanic erruptions, and remarkable
meteoric appearances since the year 1821, by K. E. A. v. Hoff,
9th part. — This forms the concluding portion of an important list of
meteoric phenomena, registered with considerable minuteness. It
terminates with a summary exhibited in the following tables, com-
prehending 10 years, from 1821 to 1830: —

January .
February .
March

April
May
June

July . .
August .
September

October .
November
December

Total

VOL. II.

KARTIJQUAKFS.

VOLCANIC ERUPTIONS, (

NORTH

SOUTH

NORTH

SOUTH

HEMISPHERE

HEMISPHERF

HEMISPHERE

HEMISPHERE

31

2

1

0

36

0

2

1

31

1

2

0

98

3

5

1

29

1

1

2

33

3

0

0

33

1

1

0

95

5

2

2

20

3

2

1

31

2

1

0

24

3

0

0

75

8

3

1

41

2

1

2

26

1

1

1

34

1

4

1

101

4

6

4

369

20

16

8

2

c

886

Analyses of Books,

[Nov.

From this table it appears that the occurrence of earthquakes in
the different seasons was as follows : —

NORTH HEMISPHERE

e three harvest i
„ winter
„ spring
„ summer

ER

B.

SOUTH HFMISPHERE.

1th

S = 101

In the three harvest months =5

»y

98

winter „ 8

a

95

spring „ 4

n

76

„ summer „ 3

In reference to the hours at which they took place during the
same period, we have the following data for earthquakes : —

A.M.

P.M.

Prom 12 to 1 o'clock.

= 15

6

it 1 3? 2 „

11

7

„ J J, O 3f

12

10

>t 3 3> 4 „

14

13

V 4 ,, 5 „

16

8

« 5 „ o „

11

6

79

50

„ 6 „ 7 „

= 6

5

,, 7 „ 8 „

8

13

i> 8 „ 9 „

7

11

„ 9 „ 10 „

8

10

„ 10 „ 11 „

18

8

,, 11„12 „

5

6

52

53

Total

^Ts" 1

103

Earthquakes at Basle. — According to Professor Merian, the
earthquakes at Basle are correctly estimated as follow : —

In the 11th century, 3
„ 14th „ 4
„ 15th „ 5
„ 16th „ 23

In the 17th century, 59
„ 18th „ 24
,. 19th „ 4

118 occurred in the different months, as follows :-

122

January. .

12

April . .

5

July ... 7

October . . 11

F'cbruary .

14

May . . .

11

August. . 8

November . 14

JVIarch . .

6

June. . .

3

September 12

December . 15

The most severe earthquakes were on the 18th October 1356,
when 300 persons lost their lives; on the 2 1st July 14 16, 7th Sep-
tember 1601, and 17th November 1650.

Compounds of Ferro-cyanodides and Ammonia , by Dr. Bunsen,
of Gottingen.

1. Ammonia Ferro-cyanodide of Copper. — When a salt of copper
is precipitated by ammonia, and an excess of the latter added, so as
to re-dissolve the precipitate, if ferro-cyanodide of potassium be brought
in contact with the solution, a precipitate is not immediately pro-

1835. J Poggendm-ff's Annalen der Physik, ^c. 387

duced, but after standing for some time, or by boiling, a brown cry-
stalline substance falls in fine scales. After drying, the substance
forms a brownish yellow mass, which is soluble in ammonia, but not
in water or alcohol. When heated in a glass tube it becomes first '
blue, then purple-red, and assumes a dark colour, but gives out no
water. By caustic alkalies it is resolved into hydrate of copper, and
ferro-cyanodide of ammonia ; and by acids into ferro-cyanodide of
copper, and ammoniacal salt.

Dr. Bunsen found its comix)sition to be, iron 13*20, copper 30*33,
cyanogen 33*08, ammonia 16-14, water 2*25 =2, 4, 6, 4, 1, atoms
respectively. This composition may be expressed, considering the
ammonia as occupying the place of water, by 2 Pe Cy -f 2 Cu Cy -f
4 N H-i -f HO = 76- 125 the atomic weight.

2. Ammonia Ferro-cyanodide of Zinc is prepared in the same
way as the preceding. It is a white crystalline powder. Analysis
afforded for its composition, iron 13*15, zinc 32*27, cyanogen 39'04.
ammonia 11-.50, water4*0=2FeCy + 2 Zn Cy + 3 NHa + 2 HO.

3. Ammonia Ferro-cyanodide of Mercury. — The preparation of
this salt is attended with some difficulty ; because, ammonia nitrate
of mercury dissolves in nitrate of ammonia when excess of alkali is
present. When Ferro-cyanodide of potash is added to this solution,
a yellowish precipitate subsides, which, when the solution attains its
proper degree of dilution, settles on the sides of the glass, in the form
of small, transparent, shining, wine-yellow, four-sided prisms. But, in
order to obtain them, several precautions are necessary. The solution
must contain as little water as possible. The solution must not be too
much concentrated, nor must the precipitation be conducted by heat,
because part of the mercury will be reduced, and the product will
have a gray colour. It is best to discover the necessary degree of
concentration by some preliminary trials, — to precipitate the com-
pound in a vessel surrounded by ice, and then to agitate the solution.
A yellowish precipitate subsides, from which the supernatant liquor
is to be removed, and a quantity of concentrated ammonia poured
over it. As long as the salt is impregnated with ammonia it retains
a fine citron-yellow colour, and crystalline structure. By drying in
the open air it undergoes partial decomposition. When treated with
water it becomes red. It consists of iron 8*58, mercury 59*09, cyano-
gen 23*74, ammonia 5*19, water 3*40: expressed by Fe Cy -j- 2 Hg
Cy + NH3 4- HO.

4. Ammonia Ferro-cyanodide of Magnesium is procured by
adding to a solution of a magnesia salt, ammonia, till no further pre-
cipitation takes place, and then pouring in a solution of ferro-cyano-
dide of potassium. After standing or boiling, a white powder falls.
It consists of iron 18*86, magnesium 10*72, ammonia 10*75, cyano-
gen 56*27, water 3*40 = 7 (Fe Cy + 2 Mg Cy) + 5 (Fe Cy + 2
NH3 Cy) + 6 HO.

Another compound was formed by using ferro-cyanodide of calcium
instead of the salt of potash. The constituents were, iron 18*24,
magnesium 8*93, ammonia 11*43, cyanogen 53*91, water 7'49,
abstracting the lime which was found in it. This is equivalent to
(Fe Cy + 2 Mg Cy) + Fe Cy + NH^) _^- 2 HO.

2c2

388 Analyses of Books. / [Nov.

II. — Philosophical Transactions of the Royal Society of
London, for 1835. Part i.

Geology.

1. The Bakerian Lecture. On the proofs of a gradual risin»; of
the Land in certain parts of Sweden. By Charles Lyell, jun., Esq.

It may be known to our readers that Mr. Lyell advocates the
opinion first stated and ably supported by the celebrated John Ray,
in his admirable Physico Theological Discourses, that the changes
which we observe on the earth's surface can be satisfactorily explained
as the effect of causes still in operation. The present paper is devoted
to the investigation of some important facts which contribute to sup-
port his position.

It was remarked by Celsius, Play fair, and Von Buch, that a con-
siderable alteration in the relative levels of the land and sea was
observable on the coasts of Sweden ; and subsequent observation had
tended to confirm this affirmation. Still the fact had only been
noticed in a limited number of places, and, therefore, it did not
appear to what extent these changes extended. IMr. Lyell, in the
summer of 1834, visited Sweden for the purpose of examining into
the question. He proceeded first to Calmar, in lat. 56''-41, whose
castle, he inferred from the appearances which he observed, was
originally founded under water, and that a projecting rim of dressed
stone may have formed the visible base of the building which now
rises to the height of 25 feet above. The true base is now situated
2 feet above the present level of the Baltic. Proceeding to Stock-
holm, he found ridges of sand 30 feet above the level of the sea at
Solna, about a mile to the north-west of the city, and part of which
traverses the city, containing, in pits in their neighbourhood, Car^
dium edule, Tellina Baltica, Mytilus edulis, Littorina crassior,
Littornia littorea, and a Palludina, perhaps ulva. Similar ridges
exist about three miles to the south of Stockholm, at Brankyrka, where
Neritina fluviatitis exists, a fresh water shell which lives abun-
dantly in the brackish water of the Baltic. Bulimus luhricus was
also found. The height of the latter shells is 70 feet. At Soder-
telge, lb' miles south of the city, a similar deposit occurs at a height of
90 feet. In cutting a canal at this place several buried vessels of
great antiquity were found, besides a small wooden house, at a depth
of 64 feet.

In examining the country about 45 miles north-west from this
point, between the towns of Torshalla and Arboga, the author found
Tellina Ballica, in an unctuous clay. This locality is 7^ miles
from Stockholm, and 89 from the general coast line.

Some marks in the suburbs of Stockholm are then brought forward
which serve to prove that the elevation of the land during the last three
or four centuries must have been very limited. In the neighbour-
hood of Upsala ridges occur, containing shells at an height of 100 feet
above the river which flows at their base ; and in a meadow to the
south of the town, the Glaux mnritima and Tri'^lochin mariti-
mufi, plants which flourish in salt marshes near the sea, (although
they have been found in Germany and France, near saline springs),
are met with. The ridges consist of thin layers of sand, loam and

1836.] Philosophical Transactions, ^c. 389

gravel, and marl deposited in gneiss and granite. The shells were
found in the marl, and consisted of Tellina B allien, Cardium edule,
Mijtilis edulis, Litlorina liltorea, Litlorina rudis, L. crassior,
Palkidina ulva? Rissoa parva, Neritina Jliiviatilis, Bulimus
luhricus.

At Oregrund, a horizontal line which was formed on a rock in
1820, to note the standard level of the sea, was found to be .5^ inches
above its surface. Several rocks were also pointed out which the
inhabitants remembered to have been barely covered with water
about forty years ago, but which now rise one and two feet above the
water.

At Gefle, the author came to a large tract of stiff blue clay, like
that near Upsala, covered with sand six or eight feet deep, and con-
taining Mytilus edulis and Tellina Baltica. Low pastures one
to three miles inland, were pointed out where the older inhabiants
remembered that boats and ships had sailed. It was reported that a
vessel and anchor were found at Uggelby, 16 miles from the sea. In
the island of Lofgrund, a mark cut at the level of the sea in 1 73 1 ,
was found to be 2 feet (J inches above its present level. By a mark
at St. Olof's Stone, in Edsko Sund, the difference of the level
between 1820 and 1834 was 3*58 inches.

According to the account of Mr. Dickson, resident at Lundswall,
the difference in the level during the last fourteen years is six or
eight inches.

Near Uddervalla, on the west coast of Sweden, there is a narrow
valley in the gneiss which is filled up with shells, sand, and clay,
which rise 206 feet above the sea; and at two miles north from this
place, and two miles from the sea, barnacles were found, round the
boundary of gneiss, at its contact with a bed of shells, and also small
zoophytes {Cellepora? Lam.) The shells found in this deposit were
Pliolas crispata, Mya truncata, Anatina myalis, Saxicava
rus;osa, Tellina triangularis, T. Baltica, Astarte, Cardium
edule, Mijtilus edulis, Modiola barhata, Pecten Islandicus,
Terebratula, Patella testudinaria ? Patella noachina, Mar-
garita striata, Litlorina littorea. Litlorina ? Turritella ? Na-
tica, Velutina, Fusus, Fusus corneus, Buecinum undatum,
Balanus sulcatus, Balamis tulipa. Echinus. In the small island
Gulholmen, in addition to these species, he obtained Oslrea edulis
and ceritliium reticulalum, in a similar deposit. A rock on the
coast of this island was found to have been raised 16 inches above
the water within the last forty years. A similar observation was made
in the island of Marstrand. On the banks of the river at Gothen-
burg, the author observed a deposit of blue clay filled with a great
variety of shells ; amo^ig others, Lutraria compressn , Mactra
suhtruncata, very abundant ; Tellina solidula, Donax trunculus,
Cifprnna Islandica, Venus gallina, Cardium edule, Litlorina,
littorea, Turritella terehra, Rostellaria pes pelicani, and Bur-
cinum reticulalum. This part of the estuary is now filled with
fresh water.

The author concludes, from his observations in Sweden, 1st, That
the tract of country which separated the Baltic from the Cattegut
was much narrower at a comparatively modern period ; for shells

390 Analyses of Books. [Nov.

like those of Udilevalla have been found as far inland as Lake Rog-
varpen, in Dalsland, on the west of Lake Wener, at a height of
about 200 feet. Lake Maeler has obviously been an arm of the sea ;
while the distance between Lake Maeler and Wener is only 70 miles.
2nd, He conceives that it is the land which is rising, and not the sea
which is sinking, that causes the alteration in their relative levels.
3rd, The rate of alteration of the relative levels is different in diffe-
rent places.

The first and last of these conclusions appear to be indisputable ;
but the second might, perhaps, be questioned. Tf Sweden were the
only country where this remarkable phenomenon occurred, then the
conclusion might readily be granted ; but the fact that similar changes
are in progress in Scotland and Ireland, throws an obstacle in the way
of this explanation. The discovery of a deposit of marine shells, similar
to those in Sweden, at a distance of nine or ten miles from Glasgow,
and nearly as many from the sea, (Records, i. 131.) demonstrates an
alteration in the relative level of the ocean, analogous to the appear-
ances described by Mr. Lyell ; while the observations of Dr. Thomas
Thomson have rendered it certain that this change is not confined to
one spot, but is very strikingly exhibited at Oban, in Argylshire. At
Falkirk, in the neighbourhood of the Frith of Forth, I may notice,
that deposits corresponding with that on the Clyde, have been ob-
served containing shells ; and caves have been described in Ireland
which are now elevated very considerably above the level of the sea.
It is but justice to add, however, that on the east coast of Scotland,
the sea is making daily encroachment.

Some account of the eruption of Vesuvius, which occurred in
the month of August, 1834, 8fc. By Charles Daubeny, M.D.

The first part of this paper (of which some account is given in
"Records" vol. ii. 145.) contains an account of the eruption of
Vesuvius, extracted from the manuscript notes of Monticelli. Dr.
Daubeny found the various vapours issuing from parts of the surface
of the crater to consist of steam and muriatic acid, with a slight trace
of a sulphur acid. No sulphuretted hydrogen nor azote were detected .
The steam from the lava afforded besides muriate of ammonia.
CTo be continued. J

III. — Manual of Pathology, containing the Symptoms, IMag-
nosis, and Morbid Characters of Diseases, Sfc. By L.
Martinet, D. M. P., translated by Jones Quain, M. D.,
4th Edit. London, 1835, Simpkin and Marshall.

This little work comprehends a great quantity of very useful infor-
mation. It is divided into two parts ; the first portion being devoted
to an excellent detail of the proper modes of examining the body,
as distributed under the great divisions, of the head, chest, abdo-
men and primary tissues ; and the second part, comprehending the
diagnosis and pathology of disease, under the titles of the brain and
its appendages : the spinal marrow and its membranes ; air tube.

1835.] Scientific Intelligence, 391

lungs and heart with its membranes ; digestive organs and their con-
nexions ; urinary organs ; organs of generation ; cellular tissue ;
membranous textures ; vascular and nervous tissues j constitutional
diseases ; cutaneous disorders ; fevers ; poisons.

This arrangement, although perhaps, equal to any of its contem-
poraries, is certainly very exceptionable. Thus, w^e have inflamma-
tions of the same membranes placed in different divisions ; oesopha-
gitis, pharyngitis, inflammations of mucous membranes, are classed
along w\i\\ worms, and peritonitis or inflammation of a serous mem-
brane ; and apart from cystitis, gonorrhea, coryza or inflammations of
mucous membranes. Until diseases are considered in connexion with
the structures in which they exist, attempts to form true views of
their essential nature will be vain. Bichat by his proposal to classify
disease, according to the anatomical, or rather we might say, chemical
nature of the structures of the body, paved the way for the true basis
of a science. His successors have not, it is to be regretted, followed
up his views, or if they have done so, they have not extended them
to the present state of our knowledge. The case before us fully
illustrates this position ; still the book is a valuable one, and has lost
nothing by its translation. For the Editor's labours have not been
confined to mere " doing it into English." He has added a concise
compend of cutaneous diseases, and throughout the work has sup-
plied numerous useful observations.

Article X.

SCIENTIFIC INTELLIGENCE.

I. — Excise Committee of the Royal Society.

Report on the Hydrometer.— 'The report states, that with regard
to the substance alcohol, upon which the Excise duty is to be levied,
there appears to be no reason why it should be considered as absolute.
A definite mixture of alcohol and water being as invariable as alco-
hol itself, and can more readily, and with equal accuracy be identified
by that only condition to which recourse can be had in practice, viz.,
specific gravity. The committee proposes, that standard spirit shall
have a specific gravity of 0*92 at the temperature of 62" Fahr.,
water being unity at that same temperature, or in other words, that
at 62^, it shall weigh iVoth, or f f th of an equal bulk of water.
The temperature of 62° is adopted, because it is that at which water
was taken in adjusting the weights and measures, and the spec. gr.
092 is recommended in preference to 0*918633, the present specific
gravity of proof spirit at 62^, on account of the more simple nature
of the fraction. By this alteration, the new standard will be weaker
then the old proof spirit, in the proportion of nearly 1 * I gallon of
the present proof spirit per cent. The specific gravity of absolute
alcohol has been differently stated by chemists. Saussure makes it
•7910 at 60°. Berzelius .7947 at 59 \ Gay Lussac -79235 at 64°.

d^

Scientific IntcUiyence,

[Nov.

Chaussier '7980, but assuming the mean, the proposed standard
would contain nearly one-half by weight of absolute alcohol.

The committee considers the hydrometer the best instrument in
the hands of the excise officer for ascertaining the specific gravity.
Bate's hydrometer, by means of a scale of 50 parts and 18 weights
or poises, has a range of 900 divisions, ajid expresses specific gravities
at the temperature 62", while Sike's instrument has a scale of 500
divisions only, and yet these are smaller than on Mr. Bate's instru-
ment. " Hence, the facility of reading the more extensive scale on
Bate's instrument, is greater than with the more limited scale of
Sike." Mr. Bate has constructed the weights (which in this instru-
ment are immersed in the fluid) of different specific gravities, so that
each successive weight should have an increase of bulk over the pre-
ceding weight, equal to that part of the stem occupied by the scale,
and an increase of weight sufficient to take the whole of the scale
and no more down into the liquid. This arrangement requires great
accuracy of workmanship, and enhances the price of the instrument.
As it can only however, ascertain specific gravities at the tempera-
ture of 62o, it would be inexpedient to use the term specific gravities
for the numbers it would show ; the term indication, being that
already in use, would be much better, and involve no risk of ferror.
The committee recommends attention to the accuracy of the thermo-
meters employed.* It advises the construction of three tables for
practical purposes. The first, which shall indicate the same strength
of spirit at every temperature ; not however, expressing the quality
of the spirit by any number over or under proof, but marking at once
the number of gallons of standard spirit, contained in, or equivalent
to 100 gallons of the spirit under examination. Thus, instead of saying
23 over proof, it is proposed to insert 123, and in place of 35-4 under
proof, to insert 64 6, as is illustrated in the following table: —

Tempera

ture 60°.

INDICATION.

STRENGTH.

INDICATION.

STRENGTH

9001

114-5

9565 .

. 63-7

3

114-3

6.

. 63-4

5

114-2

8.

. 631

7

114 0

70.

. 62-9

9

113-9

72.

. 62-6

9011

113.7

9574.

. 62-4

3

113-6

6.

• 62-1

5

113-4

8-

. 61-9

7

113 3

9580.

. 61-6

9

1131

2.

. 61-4

The second \

table

is intended

to show the bulk of

spirit of

strength, at any temperature, relative to a standard bulk of 100

* That thennometers are liable to become inc. rrect in the course of time, has
been much insisted on, since the publication of the observations made at Geneva
on this subject. Dr. Thomson has, liowever, shown that tliis does not hold good
with regard to the accurately constructed thermometers of Crichton of Glasgow,
even after a lapse of forty years. See on Heat and Eleclricily, [J. 40. — Edit.

1835.]

Scientific Intelligence,

393

gallons at 62^. In this table, a spirit which had diminished in
volume at any given temperature, 0*7 per cent, for example, would
be expressed by 1)9*3. These two tables, therefore, will give first the
proportion of standard spirit at the observed temperature, and next
the change of bulk of such spirit, from what it would be at the
standard temperature. Thus, at 51'', with 8240 indication, 100
gallons of spirit under examination, would be equal by the first table
to 164-8 gallons of standard spirit at that temperature 3 and by the
second table, 99*3 gallons of the same spirit would become 100 at 62",
or in reality, contain the 164*8 gallons of spirit in that state in which
only it is to be taxed. But as neither of these tables can alone be
used for charging the duty, for neither can express the actual quan-
tity of spirit of a specific gravity of 0*92 at 62^ in 100 gallons of
stronger or weaker spirit, at temperatures above or below 62°, a third
table is essential, combining the two former, where the quantities
should be set down in the actual number of gallons of standard spirit,
at 62^ = 100 of the spirit under examination, and the column of
quantities may be expressed by the term value. Thus,

Temijeratare 45°.

INDICATION. STRENGTH. VALUE.

9074

7
9

81
3
5
6
9

90
3

114.5
114 3
114*2
114*0
113-9
113*7
113-6
113*4
113-3
1131

Temperature 75°.

INDICATION. STRENGTH. VALUE.

8941
4
5
8
9
52
3
6
7
9

114-5
114*3
114-2
114*0
113 9
113*7
113*6
113*4
113 3
113*1

Although this is the only table necessary to be used by the Excise,
the committee recommended printing the other two, because they
must be constructed, and it would be matter of regret, that they
should not be rendered permanent.

II. — Passage of Electricity through Liquids,^

The apparatus employed by Sr. Matteucci in determining the con-
ductibility of electricity through liquids, consisted of a small table
with four legs, pierced with three circular holes, of which two are
destined to hold small glass vessels, and the third, situated between
the others, contains a porcelain vessel pierced in the centre. The
two extreme vessels contain a layer of mercury ; in the middle one is
placed the liquid to be examined. A communication is established
between the three vessels by means of two platinum wires, in the
form of a horse shoe, and retained by a bit of gum lac in the proper

* Bibliotheque Universelle, February, 1835.

394 Scientific Intelligence. [Nov.

position. Two copper urires which are soldered each by one of their
extremities to a plate of platinum, have these extremities in contact
with the mercury, while the other two extremities are united, the
one to the galvanometer and the other to a copper plate. The second
extremity of the galvanometer is soldered to a zinc plate. The cop-
per and zinc plates possess the same dimensions, — the side being a
decimetre (3*93 inches) in length. The galvanometer is provided
with two needles, and the copper wire which forms the circumvolu-
tions consists of live wires, united and soldered at their extremities.
The heat of the finger alone, applied to an iron w^ire wound round
the extremity of the galvanometer developes a thermo-electric current,
producing a deviation of 60».

While endeavouring to obtain a constant current he found that

1. The loss of electro-magnetic power is very rapid immediately
after the circuit is completed, the eflfect being greater in proportion
to the intensity.

2. This power continues to diminish during a greater or less time
after the communication between the two poles has been established.
The motion at last ceases, and the power remains the same during a
very considerable time.

3. The time required to arrive at this point is proportional to the
original electrical power.

4. When the same liquid is in contact with all the pairs of a pile
the electro-magnetic power reaches its maximum of intensity, with a
rapidity proportional to the number of the pairs of plates.

5. Piles previously charged, but without completing the circle,
attain more rapidly the point at which their electro-magnetic power
becomes constant.

6. A pile, when it has arrived at the point where its effect is per-
manent, recovers a portion of the electro-magnetic power when the
circuit is interrupted which had been completed for some time. In
again establishing the communication the power returns to the point
at which it left off. This trial may be repeated several times with
the same effect.

7. The electro-magnetic power is rapidly developed at the instant
when the circuit is interrupted.

8. When the electro-magnetic power, proceeding from a pile of
four or eight pairs, is revived, the liquid employed being well-water,
or water slightly saline, the power is never equal to the original
intensity.

He had recourse to two methods for the purpose of obtaining a
constant current. The shortest method was to allow the needle to
acquire a fixed deviation, then having interrupted the circuit, to close
it at the end of five minutes, for an instant, which is sufficient to
obtain a complete deviation ; he observed the number of degrees
which the needle indicated. The deviation remained the same, in
repeating the operation every five minutes during a long time. The
following are the results obtained for the conductibility of different
solutions, the quantity of water being 1000 to 10 parts of the dissolved
substance : —

1835.]

Scientific Intelligence.

395

Distilled water ut 38- J F. 2 '
Potash sulphate of alumina 4°30
Chloride of lime .
Chloride of potassium
Sulphate of magnesia
Sulphate of iron . .
Chloride of sodium .
Nitrate of potash . .
Muriate of ammonia
Chloride of barium .
Acetate of lead . .

Binoxalate of potash . .14
Sulphate of copper . . 20
Nitrate of mercury . . 35
Nitrate of silver ... 45

Oxalic acid 14

Tartaric acid ..... 10
Muriatic acid . , . .10
Sulphuric acid ... 8
Nitric acid ..... 8

Potash 15

Ammonia 8

He found the opinion of Faraday correct, that the conductibility
which non-conducting solids acquire by fusion, proceeds from the
same source as the conductibility which these bodies communicate to
water by their solution in the latter. This is strikingly exemplified
in the cases of sugar and iodide of sulphur.

He found the conductibility of phosphate and pyro-phosphate the
same ; which proves that heat does not alter the conductibility of
this substance, although it produces a powerful alteration in its che-
mical properties.

II. With regard to the effect of quantity of dissolved matter upon
the effect, he found that, with chloride of potassium, there was the
same deviation with 40 grs. to the thousand of water as with 100, —
the deviation being 40° ; and when a great quantity of salt was added
the effect was not increased.

With 10, 20, and 40 grs. of chloride of sodium the deviation was
^^. With 80 grs. 4°, and at the point of saturation it was also 4^.

When acetate of lead was employed the deviation with 10 grs. was
8''-30 , 20 grs. 9«, 40 grs. 9'"30, 80 grs. 9°. At the point of satura-
tion 6<^ to 7^". With nitrate of silver, when \ gr. was dissolved the
deviation was 3^ 1 gr. 10% 5 grs. 14«, 10 grs. 18°, 20 grs. 22^, 25 grs.
22°, 30 grs. 22°, 40 grs. 21°. Hence, the supposition is confirmed
that the increase of conductibility, which results from a greater pro-
portion of salt dissolved, remains longer when the solution, though
very feeble, possesses great conductibility.

The author ascertained a remarkable fact, which may be compared
to the known property which liquids possess, of evaporating in a
vacuum already saturated with vapour proceeding from another
liquid. We know that, in this case, while the second liquid cannot
form any more vapour, the first can evaporate in the same space, as
if this space had not been saturated with any other vapour. When
a solution has acquired the highest degree of conductibility, in such
a manner that the addition of a new dose of the salt only diminishes
it, if we dissolve in the liquid another salt, without decomposition,
the conductibility increases, as if the substance already dissolved did
not exist. The phenomenon disappears if in the mixture a decom-
position takes place, giving rise to the precipitation of an insoluble
salt. The conductibility, on the contrary, is diminished The chlo-
ride of iodine, proto-iodide of tin, chloride of copper, when added in
convenient quantities, to a solution of chloride of sodiup exhibit a
conductibility almost metallic.

396

Scientific Intelliyence.

Nov.

III. The effect of heat upon the conductibility of liquids was de-
termined by heating the intermediate porcelain vessel with a spirit
lamp. The following table contains the results : —

Distilled
Water.

50° F. 4«

77 7

1064 10

131 14

155| 17

185 21

212 27

Well
Water.

I44"i 4«

68 8

99J 13

I55j 27

1891 35

212" 41

Water saturated
with Chloride of
Sodium at 41oF.

Distilled Water,

holding in solution

_J_ of Nitrate of

Silver.

4P 7 8loi 73«

8 88i 75

1101 22 99J 77

1601 30 11 Of 82

1894 33 133i 89

"12 34 r The needU de-

223J 35 155 j> 3"^^^''"'

t at 13°,

^, ^ r It proceeds

212 ? yo** a"'^ 1

i mains at 22«.

The deviation of the needle, which expresses the conducting power
of the liquid at different temperatures, is the product of the inital
deviation by a certain co-efficient. The latter is easily obtained by
means of a co-efficient which may be expressed by ^ Calculating
the numbers contained in the preceding table, we obtain the follow-
ing deductions : —

1 . The co-efficient is not a constant number for any of the liquids
examined ; the increase of conductibility does not proceed uniformly
with the increase of temperature.

2. When the temperature is raised at first the co-efficient does not
vary much for the different liquids; the number is greater in pro-
portion to the original conducting power.

3. The number increases to the middle of the thermometric scale
most rapidly for good conductors.

4. The increase of deviation or conductibility, corresponding to a
degree of elevation of temperature, is, at the commencement of the
heating, 15' for the first liquid, 22 for the second, 17' for the third,
and 40 for the fourth. When the middle of the thermometric scale
is obtained, the mean value of the increase of conductibility corre-
sponding to a degree of heat is 19 for the second liquid, 23' for the
third, 54' for the fourth. At 212o this value is 30 for No. 1, 36' for
No. 2, and 6' for No. 3. The same value for the nitrate of silver
shews a tendency to diminish at 133"j.

IV. Marianini demonstrated that the electro-magnetic action of
simple electro- motive apparatus, is directly proportional to the surface
of these elements. And our author has found that the relation which
exists between the conducting powers of different liquids is steady,
whatever be the absolute electro-magnetic power of the current.

V. Matteucci substituted a vessel of wood for the porcelain one, of
the same size and form. It was varnished internally, and divided
into two equal parts by a thin membrane. Having filled the two
compartments with well-water, a deviation of 5** was obtained, by

1835.] Scientific Intelligence. 397

forcing a ^iven current through the liquid. The direction of the
current was changed, and the deviation continued the same. Some
drops of chloride of iodine were added to the division into which the
current penetrated ; the deviation was still 5o, and the addition of
more chloride of iodine produced no eflfect. The vessel was then
turned so that the compartment in which the water was contained,
was on the same side as the chloride had been before in the other
experiments; the deviation was then 48°. Upon turning it half
round, and consequently restoring it to its first position, the deviation
was 8o; on turning it half round again, it was 47° 30' ; and on restor-
ing it again, it was 7° 30 . Another experiment gave 6° and 32". A
third trial afforded 2o and 12°.

From these experiments we observe the great difference which a
medium possesses which is composed of two heterogeneous liquids,
according as the current penetrates by the best conducting liquid or
otherwise, the proportions being in these trials as 1 to 6.

The chemical decomposition which takes place in the pile when
the metal and liquid are brought in contact, produces on the metallic
surfaces liquid layers of different kinds and of various conductibility.
When the circuit is open the liquid becomes chemically homogeneous,
the oxides and acids which have been separated re-combine, and the
diversity of conductibility in the liquid ceases. Matteucci observes,
that by taking advantage of this fact, and by studying the relative
conductibility of liquids, resulting from the decomposition between
the plates, it might be possible to explain the loss of electro-magnetic
force by the fact of the completion of the circuit.

III. — Wichtine.

This mineral comes from Wichty in Finland. Colour, black ; frac-
ture, feebly conchoidal ; cleavages, two ; crystal, rhomboidal prism,
nearly rectangular. Scratches glass ; fuses into a black enamel ;
with borax forms a green bead. Magnetic. Sp. gr. 3*03.
According to Ravergie it consists of,

SiHca. .... 56-3

Alumina . . . 13*3

Peroxide of iron . 4*0

^ Protoxide of iron . 13*0

Lime 6*0

Magnesia ... 3.0
Soda 3-5

991

The formula is (So Al Fe.) + S, (N C Mg./.)— ilwn de Chim.
lix. 107.

IV. — Taraxacum Officinale .

The T. Officinale and palustre have generally been considered as
distinct species. Roch seems, however, to have proved the contrary.

398 Scientific Intelligence. [Nov.

for he sowed, in the garden of Erlangen, seeds of the T. officinale,
and obtained 1 T. palustrey 2 T. erectum Hoppe. T. leptoccpha-
lum Reich. ; 3 T. nigricans Rit. ; 4 T. corniculatum Rit. ; T.
officinale. — (Arm, de Scien. Nat, Aug. 1834.)

V. — Plants of Arabia, Palestine and Egypt.

M. Bor6 (Ann. des Scien, Nat, i. 1,) formed a considerable her-
barium during his travels in these countries, amounting to 233 species,
and belonging to 45 families. Several of these are natives of Britain,
as, Sargassuni vulgare ; Adiantum Capillis veneris Mount
Sinai ; Dactylis glomerata ; Avena Sativa Desert of Sinai ; Poa
littoralis El Tor; Care^ j^amcea Mount Sinai ; Char a Vulgaris
Bethlehem ; Typha angustifolia, El Tor and Mount Sinai ; Ana-
gallis arvensis Mount Sinai ; Veronica anagallis Do ; Cuscuta
eptfthimum Do ; Tragopogon major, Sonchus oleraceus Desert
of Sinai.

VI. — Chloride of Gold as a Caustic,

M. Recamibr has employed this substance dissolved in aqua regia,
in the proportion of 1 ounce of the latter to 6 grains of the chloride,
with great success in cancerous affections. A little lint is dipped in the
solution, and the diseased part is then to be rubbed with it ; and the
effect carried to a considerable depth, so as to produce an eschar which
separates in the course of three or four days. The application is to
be repeated six or eight times, according to the extent of the ulcerated
surface. Little pain accompanies its use. A case of cancer of the
neck of the uterus was successfully treated with this caustic, in the
Hotel Dieu. — (Journ. de Chim, Medic, i. 533.)

VII. — Ink permanent in the Air.

M. Braconnot, of Nancy, has published a recipe for ink, which he
says answers extremely well in Botanic gardens, and open or wet
situations, where names are required to be preserved permanently.
Take of Verdigris 1 part

Sal ammoniac 1 part

Soot i part

Water 10 parts

Mix the powders in a glass or porcelain mortar, adding at first one
part of water, in order to mix them well, then add the remainder of the
water. Shake the ink well from time to time. When it is to be
used, we must write with it upon a plate of zinc, and after some days,
it becomes hard, and cannot be obliterated by atmospherical influence
or by rubbing. The ink may be tinged with any colour, by substi-
tuting for the soot some mineral colouring matter. — (Ann. de Chim,
i, 319.)

HORARY OBSERVATIONS OF THE BAROMETER, THERMOMETER, &c.

(Made at the Manse of the Parish of Abbey St. Bathan's, Berwickshire, Lat. 55° 52' N. Long. 2o 23' W. at

I the height of about 450 feet above the sea, for the commencement of each hour per clock, beginning at 6

o'clock in the morning of Monday the 21st September, and ending at 6 o'clock in the evening of Tuesday

22d, thus extending over 36 hours, according to the suggestion of Sir John Herschel.) By the Rev.

John Wallace.

A.M.

Noon,
P.M.

47i

49

5lf
53i

55i

57

58

5n

56i

552

53^
5lf
50

8 49

Noon.
P.M.

9

48^

10

47i

11

46

12

4^

. 1

44|

2

43

3

44

4

44i

5

43f

6

46

7

48f

8

50

9

50^

10

51^

11

52f

12

54

1

54f

2

56f

3

58|

4

58^

5

55

6

52^

29-079
29-108

29-142

29-163
29-171

29-187

29-190

29-202
29-199
29-199

29-200

29-205

29-225
29-221

29-232

29-232

29-226

29-226

29-220
29-210

29-191

29-180

29-163
29-146

29-132

29-112
29-063
29-025
28-965
28-894
28-849
28-764
28-730

28-685

28-668

^28-710
28-734

W.N.W

S. E.

s.w.

Remarks.

Shifting.
E. S. E.

S.W.

E.

S.WbyW

S.W.

S. S. E.
S.W.

W.S.W

E. S. E.

•Calm, cloudless, except a bed of cirrostratus in SWn. horizon.
Calm so that wind cannot be noted ; cirrostratus gradually forming,
chiefly in southeastern qr. ; dark patches of cirrpstratus ; light hazy
clouds floating below from the southward.
Gentle breeze ; one or two fine plumous cirri in S.Wn. qr.; the bed
of cirrostratus in S.E. qr. advancing towards the zenith ; the sky
from the zenith to the horizon N.Wd. clear, except patches of cir.
— Gentle breeze ; cirrostratus increasing, in dark masses below.
Gentle breeze ; cirrostratus gradually disappearing ; some fine cirri
near the zenith, from S. S.W. to NNE; rocky cumuli in SW hor.
< Breeze increasing ; cirrostratus continuing to dissipate ; the rocky
l cumuli on S W hor. passing over to NE, cirri from SW to NE.
i Breeze decreasing ; cirrostratus in SE, cirri in NPj ; cumulostratus
\ forming in SW and pass over to NE with the wind ; light rain.
C Moderate breeze ; cirrostratus now veils the whole sky except Wn.

< qr.; towards the zenith assuming a cirrocumulative aspect ; cumu-
C. lostratus disappearing ; large rocky cumuli in SE and N Wm hors.
C Moderate breeze ; cirrostratus rather denser, in some places passing

< into cirrocumulus ; the same portion of N W qr. clear ; cumulo-
C. strati again forming in S.W. and passing over with the wind.

C Moderate breeze ; cirostratus spread over the whole sky, possessing

< a curdy cirrocvunulative form, and shewing appearances of polar-
C. ization SW to NE, cumulostrati disappeared, cumli still forming
C Gentle breeze ; cirrostratus still possesses the whole sky, and has

< descended in the atmosphere ; a few rocky cumuli still in the
C. N W ; those in the SE have dissappeared.

S Gentle breeze ; cirrostratus still lower in the atmosphere, and the
i^ curdy cirrocumulative nebiculae larger, rocky cumuli disappeared
— Almost calm ; the general character of formation same as last hour.
( Light air ; cirostratus rapidly dissipating ; S & S W portions of the
( heavens quite clear ; streaks of cirrostratus in N W & SE.
^ Light air ; portions of darkish clouds resembling cirrostratus passing
^ from S Wd.; the original stratum of cirrostratus has disappeared,

< Light air ; same kind of clouds continue to pass over the sky from
\ SWd. Several caudate meteors observed.

— So calm that the wind cannot be noted ; most of sky cloudless.
5 Very light breeze ; a few cirrostrative clouds passing over NWm.
t hor.; a light haze spread over the sky ; a few caudate meteors.
— Very light breeze ; a quantity of large black clouds passing from S W
— Light air ; a few long streaks of cirrostratus in NWm. horizon.
Light air ; cirrostratus spread over the whole sky ; dark cloud rising

rapidly from ESE, and stretching towards the zenith.
Quite calm ; dark cirrostratus veiling the whole sky except a portion

of the SErn horizon, which is clear of clouds.
Still quite calm ; cirrostratus rapidly dispersing, especially in the
NErn. quarter ; the SErn. horizon again overcast.
— Light air ; cirrostratus still veils the sky, except in NWn. qr.
C Quite calm below, but all along there has been a breeze above, which
? is now much increased ; the cirrostratus has condensed, and covers
i_ the hills with a thick fog ; passing into the nimbus with light rain.
— Light breeze, a thin sheet of nimbus veils the sky, with some rain.

-Brisk wind ; nimbus increasing ; a good deal of rain falling.
— Breeze freshening ; dense nimbus over whole sky, with much rain.
Strong and encreasing wind ; nimbus continues, with heavy rain.
Strong breeze ; dense fog on the surrounding hills ; almost fair.
Strong breeze, with dense wet fog.
— The same as last hour.
—Strong breeze ; fog gradually diminishing in density and dissipating.

< Strong breeze ; nimbus breaking up rapidly, and changing into cir-
l rostratus, having near the zenith a cirrocumulative tendency.

— Strong breeze ; cumulostrative clouds from SE passing over.

C Moderate breeze ; a large nimbus has just passed from Sd. ; several

•J large cirro-edged masses floating rapidly across the sky ; upper

(_ stratum cirrostratus ; a fine rainbow visible.
( Moderate breeze ; large masses of cumulostrative cloud psissingfrom
\ S. ; upper stratum of cirrostratus has nearly dis-appeared.

s

:3
o

CO
bJD

e?5

*!:? *^ pq fjQ

I

1^ _

OS t>

QO O

<3

Oh

03

CO
US

Pi

Very calm, cirri and cirrocumuli prevalent, in the evening deposition.

Very calm, sunshine with the sky occasionally of a thunderous appearance.

Very calm, cirri and cirrocumuli prevalent, evening overcast, slight showers.

Very calm, A.M. rain, P.M. calm, but very cloudy.

A.M. gentle wind, with cumuli floating on a blue sky, P.M. very calm, cirri

Calm, A.M. cloudy, P.M. cloudless, deposition in the evening. [abundant.

Calm, cumuli floating on a blue sky, tendency io cirrocumulus in the evening.

Gentle wind with rain, evening fair, but copious deposition.

Gentle wind, A.M. cirrostratus, P.M. cirri and cumuli, evening cloudless.

Gentle wind, A.M. heavy rain, P.iM. frequent showers, evening cloudy.

Gentle wind, frequent showers, aurora borealis in the evening.

A.M. brisk wind with frequent showers, P.M. calm, with heavy rain, cloudy.

Calm, with frequent showers, evening sky overspread with soft hazy clouds.

Brisk wind, cirrostratus prevalent, P.M. cymoid formation, 6 P.M. rain, calm.

Calm, cloudy, with tendency to rain, evening foggy.

Gentle wind, A.M. cirri with floating cumuli, P.^I. showers, distant thunder.

A.M. gentle wind, cirri and cumuli prevailing. P.M. cloudy, distant thunder.

Calm, A.M. cirri abundant, P.M. sky veiled with thundery clouds, evg. rain.

Brisk wind, A.M. floating cumuli, P.M. cloudy, evg. sudden heavy showers.

Brisk wind, sky overspread with heavy masses of clouds, frequent showers.

Gentle wind, sky generally veiled with cirrostratus, evening calm.

Strong wind A.M. heavy rain, P.M. fair, evening partially clear.

Strong wind, with abundance of cumuli floating over a blue sky.

Brisk wind with cumuli, evening calm.

Brisk wind, cirrostratus abundant, evening rainy. [evening clear.

Gentle wind, A.M. floating cumuli, P.M. a bed of cirrostratus in the west.

Calm, A.M. sky overspread with cirri, P.M. heavy clouds, wind S. Eastward,

Brisk wind, large masses of hazy clouds with showers, evening rainy.

Strong wind, A.M. partially clear, P.M. heavy clouds, evening wind gentle

Light wind, A.M. overcast, rain, P.M. foggy. [with rain'

: s

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4

1

1 1.

RECORDS

OF

GENERAL SCIENCE,

DECEMBER, 1835.

Article I.

Life of the Rev. John Flamsteed, First Astronomer- Royal.

Written by himself.

( Continued from ;^. 341.)

Finding that the edition of my works is stopt, and not
likely to proceed very speedily ; that, in the mean time, my
distempers increase, whereby I shall be disabled from carry-
ing them on as I intended ; and that, after all the pains I
have been at, and the expenses I have borne, it has been
suggested sometimes that I had little to publish, at others
that I was averse to the publishing of them : — to clear my-
self from these calumnies and aspersions, I intend (with
the assistance of that Good Providence, which I must ever
acknowledge to have directed all my endeavours) to give an
account of all my labours and studies, their beginning and
progress, with the helps and assistance I have either re-
ceived from others, or afforded them for carrying on of
theirs, that those who come after me may honestly and
sincerely prosecute these studies, depending on the favour
of God, and giving Him only all the praise. And if I begin
a little higher than I need, I hope it will not displease my
reader : for ingenious men are much delighted to know
both the beginnings and progresses of their studies, and the

VOL. II. 2 D

402 Life of the Rev. John Flamsteed. [Dec.

circumstances of their lives whom God has made eminent
in their times.

I was born at Denby [5 miles from Derby] in Derbyshire^
August 19, 1646, at a ^ of an hour past 7 at night : as I find
in some old notes of my father's, who was the third and
youngest son of Mr. William Flamsteed, of Little Hallam,
in Derbyshire. My mother Mary, was the daughter of
Mr. John Spateman of Derby. In my infancy, sickly. I
was educated [at the free-school] at Derby, where my father
lived, [till 16 years old. My father removed his family to
Denby, because the sickness was then in Derby.] At 14
years of age, when I was nearly arrived to be the head of
the free-school, visited with a fit of sickness, that was
followed with a consumption, and other distempers ; which
yet did not so much hinder me in my learning but that I
still kept my station till the form broke up, and some of my
fellows went to the Universities : for which, though I was
designed, my father thought it not adviseable to send me,
by reason of my distemper. [Recovered by God's blessing :
went a journey to Ireland in the months of August and
September, 1665.] Wrote De cBquatione diemm, and made
the tables for it, 1665.

Languishing then at home, I had Sacrobosco De Sphcera
put into my hands, I had read a great deal of history, civil
and ecclesiastical, before. This was a new subject to me;
and having turned so much as I thought necessary for my
use into English, I proceeded to make dials by the direction
of ordinary books: and having changed a piece of Astrology
I found amongst my father's books, for Street's Caroline
Tables, set myself to calculate the planets' places by them,
and thus enquire the reasons of them : in which I found
small satisfaction ; that author being very concise and
short, and leaving the reasons of his processes to be learnt
from others.

Having calculated an eclipse of the Sun, by these tables,
that was to happen, June 22, 1666, I imparted it to a
relation of mine, who showed it to Mr. Immanuel Halton,
of Wingfield Manor ; who, coming soon after to see me,
and finding I was not acquainted with the astronomical
performances of others, sent me Riccioli's Almagest, and
Kepler's Rudolphine Tables, with some other mathematical

1835.] First Astrommer- Royal. 403

books, to which I was, till then, a stranger. He was a
person of great humanity and judgment, a good Algebraist,
and endeavoured to draw me into the study of Algebra, by
proposing little problems to me : which, having not long
before made myself acquainted with Euclid, I gave him
geometrical resolutions to ; and never troubled myself with
Algebra till I came to London, where I found every small
pretender to mathematics set up for an Algebraist.

This eclipse I observed afterwards : but, not being fur-
nished with proper instruments, nor yet acquainted with
the best way of observing, I cannot think the observations
exact enough to be published.

Another eclipse of the Sun, happening two years after,
on the 25th of October, 1668, I calculated the times of the
appearance from the Caroline Tables; and afterwards ob-
served it. But, not being yet furnished with convenient
instruments for measuring and correcting the times, I could
not believe it accurate enough to be published : though I
found by it that the tables differed very much from the
heavens.

The French Observatory was built this year, and Signor
Cassini called from Italy to direct it : who now published
his Tables for finding the Eclipses and Configurations of
Jupiter's Satellites. These fell into my hands some three
or four years after ; and were of good use to me, however
faulty when I began to observe them.

In the following years, 1669 and 1670, 1 compared Jupiter
and Mars with some fixed stars, near which they passed :
but, the observations (being made with short glasses of two
feet, and only by estimation of the planets' distances from
them, and comparing them with the small distances of fixed
stars derived from Tycho's places) were not to be relied on.
Only, I learnt by them that those distances were faulty :
and the planets' places much different from those given in
the ephemerides.

Mr. Street's equation of natural days being very much
different from that used by Tycho Bullialdus, and Wing, I
had spent many thoughts upon it, at the same time as I
remember I was calculating the solar eclipse : and at last
found that supposing the earth's revolution to be equable
about her axis, it could be no other than the difference of

2d2

404 Life of the Rev. John FlamsteecL [Dec.

her mean and true right ascension ; and consequently that
the equation of the earth's orbit turned into time must
make one of the ingredients or parts of it, and the difference
of her longitude and right ascension the other. Whereupon
I wrote a small tract about the inequalities and aquations
of natural days; which, having turned into Latin, I showed
to Mr. Halton, who approved of it : and six years afterwards
it was printed with Mr. Horrox's posthumous works, and
put an end to all that controversy.

The following years, till 1669, 1 employed my spare hours
in calculating the places of the planets, observed by Heve-
lius, and related in his Mercurius sub sole visus, from the
Caroline Tables : whereby I found they agreed not so well
with the heavens as I presumed they had ; and that further
observations were requisite to correct them.

I could not think of any more proper than those of the
moon's and planets' appulses to fixed stars, or transits by
them : considering that they required but a slender appara-
tus of instruments, and might be taken by a single observer
with ordinary assistance. I collected some remarkable
eclipses of fixed stars by the moon, that would happen in
the year 1670; calculated them from the Caroline Tables;
directed them to the Lord Viscount Brouncker, then Presi-
dent of the Royal Society, and conveyed them into his
[hands]. This labour was well accepted both by him and
them, and brought me letters of thanks both from their
Secretary Mr. Oldenburg, and Mr. Collins one of their
members, with whom I had a faithful friendship and inge-
nious correspondence afterwards, so long as they lived. My
letter was dated November 4th, 1669 : Mr. Collins and Mr.
Oldenburg, in January following.

From this time I began to have accounts sent me of all
the mathematical books that were published either at home
or abroad. In June 1670, my father, taking notice of my
correspondence with them and some other ingenious men
whom I had never seen, would needs have me take a journey
up to London, that I might be personally acquainted with
them : that being the time of the year when his affairs would
allow me liberty. I embraced the offer gladly, and there
became first acquainted with Sir Jonas Moore [His Majesty's
Surveyor of the Ordnance], who presented me with Mr.

1835.] First Astronomer- Royal. 406

Townley's micrometer, and undertook to furnish me with
telescope glasses at moderate rates. I left monies in Mr.
Collin's hands to pay for them : and in my return visited
Dr. Barrow, and Mr. Newton, the Lucasian Professor of
Mathematics at Cambridge; and Dr. Wroe, then a fellow
of Jesus College there, with whom I corresponded frequently
the four following years. Entered myself at Cambridge in
Jesus College.

About this time Mr. Newton was engaged in experiments
about Light and Colours, and the improvement of tele-
scopes ; of which I had some account sent me by Mr. Collins :
though his theory and the description of his new contrived
telescope came not out till February 1671-2; when it was
published [in the Transactions^ No. 80.

I could not at first yield to this theory : but, upon trial,
found all the experiments succeeded as he related them ;
which kept me silent and in suspense. For, I could never
think that whiteness was a compound of all the different
sorts of rays of light mixed ; because I found always that
what he called whiteness was only sun-light, or solar rays : .
and that when the rays, which he called whiteness, were
mixed with the blue, they formed a green ; which showed
they were of the nature of yellow.

My first telescope glasses were not procured me till about
Michaelmas, 1670 : but the eye-glasses suited not with
them. And both Mr. Jonas Moore and Mr. Collins having
employments that kept them continually in business, I
could not procure such eye-glasses for them till the next
autumn, 1671. [Here the description of Mr. Townley's
micrometer is to be inserted ; with the tables for turning
the revolves and parts, into minutes and seconds : as also
the figures and descriptions of my own, with the like
tables.]

In the mean time, some affairs of my father's requiring
it, in the month of June this year, I made a journey into
Lancashire, and called at Townley, to visit Mr. Christopher
Townley, who happened to be then in London. But, one
of his domestics kindly received me, and showed me his
instruments, and how his micrometer was fitted to his
tubes : and from this time forward we often conferred by
letters. I procured Mr. Gascoigne's and Crabtree's papers

406 Life of the Rev. John llamsteed. [Dec.

from him ; and Mr. Horrox's theory of the moon, to which
he had begun to fit some numbers; but perfected none that
I remember.

About this time, Mr. Horrox's remains and observations
having been collected by Dr. Wallis, were in the press. [I
found his theory (of which a correct copy had fallen into
my hands) agree much better with my observations than
any other. Hereupon- 1 fitted numbers to it, which with
an explanation of it, were printed with his works.] Mr.
Collins advised me to print my discourse concerning the
Equation of natural days with them : which I consented to
do ; and sent it up to him for that purpose, translated into
Latin.

[In March, 1671, setup a pole to raise my glasses, at
Derby.] It was October, 1671, before I could get my
tubes and micrometers in good order for observations. I
had no pendulum movement to measure time with : they
being not common in the country at that time. But, I took
the heights of the stars, for finding the true time of my
observations, by a wood quadrant about eighteen inches
radius, fixed to the side of my seven foot telescope ; which
I found performed well enough for my purpose.

For, I had before resolved not to attempt anything that
lay out of my power, or for which I had not made such pro-
vision as might probably afford me success : and therefore
I resolved to confine myself to such observations as required
no very accurate knowledge of the times. Such were the
diameters of the luminaries ; small distances of the fixed
stars; the greatest elongations of Jupiter's satellites, &;c. ;
which might be of use to me in the further progress of my
astronomical studies. To such as these I confined myself
at first : and that Good Providence, that had designed greater
things to be afterwards done by me, gave me success beyond
my hopes or expectations. Having determined the diame-
ters of the sun, in his apogee and perigee, I saw the eccen-
tricity of the earth's orb was bisected. And observing the
moon's diameters in her appulse to the Pleiades, November
6th, 1671, when she was near the opposition of the sun,
and again February 23rd, 1672, when she was not far from
her quartile, I found that whereas the visible diameter ought,
according to the lunar theories of Bullialdus, Wing, and

1835.] First Astronomer- Royal, 407

Street, to have been greater at the quartile, or latter time,
by about 45" than at the opposition in November, on the
contrary it was less by about 1'. 20'. Which showed that,
from the opposition to the quartile, she removed from the
earth : whereas their theories made her approach nearer to
it, making her diameters bigger at the quartile than at the
opposition by 1'. 30"; and that they erred also very sensibly
in her visible place.

But, enquiring her visible place and diameters, by the
tables I had fitted to Mr. Horrox's lunar theory, I found
her place agree nearly ; and her diameter at the full moon
bigger than at the quadrature by about 50' : which convinced
me that Bullialdus's, Wing's, and Street's theories were
erroneous ; and Horrox's near the truth. I did not then
think the theory perfectly agreeable ; for I found a dissent in
my observations from it, by reason I had not yet attained the
the knowledge of a further necessary diminution of her dia-
meters depending on her distance from the sun, with which
Mr. Newton's corrections and emendations of that theory
have furnished me since. These observations I imparted to
Mr. Oldenburg, with the same remarks upon them ; which
occasioned their joint desires that, now Mr. Horrox's re-
mains were in the press, I would add the tables I had fitted
to his theory, with an explication of the theory itself, and
directions to calculate the moon's places, &;c., by the tables :
which I willingly did, fitting the radixes of my mean mo-
tions to the meridians both of London and Derby, where I
then thought my abode fixed, and hoped to carry on my
observations to greater accuracy : for which, in my
thoughts, I was frequently forecasting.

In the spring of the year, 1672, I excerpted several ob-
servations from Mr. Gascoigne's and Crabtree's letters,
that had not yet been made public ; which I had turned
into Latin, and resolved to publish in the first volume of
Celestial Observations taken at the Observatory. Amongst
Mr. Gascoigne's letters I found some wherein he showed
how the images of remote objects were formed in the dis-
tinct base of a convex object glass. From these I got my
dioptrics in few hours ; having read Descartes' Dioptrics
before, but learnt little by them because he discourses not
of this subject : his main business being to show how by

408 Life of the Rev. John Flamsteed, [Dec.

elliptical or hyperbolical glasses all the rays of light that
fall on the object parallel to the axes may be collected into
one point of the image in the distinct base, supposing all
the rays of light of the same species and liable to the same
law of refraction ; which yet Mr. Newton demonstrated
they were not, by many experiments published in this year's
Transactions : and this is the only thing that I can perceive
for which Descartes' Dioptrics have been so celebrated. I
finished my transcript of Mr. Gascoigne's papers May 12th,
176*2. The spare hours of the remaining part of the year
were employed in my observations, as the weather suffered
me; in preparing advertisements of the Appulses of the
moon and planets to fixed stars for the following year;
which were printed by Mr. Oldenburg in his Transactions,
with some observations of the planets I imparted to him.

Whilst I was enquiring for the planets' appulses to the
fixed stars by the help of Hecker's ephemerides, I found
that in September, 1672, the planet Mars, then newly past
his perihelion and opposition to the sun, would pass amongst
three contiguous fixed stars in the water of Aquarius : and
that, by reason he was then very near the earth, this would
be the most convenient opportunity, that would be afforded
of many years, for determining his, and consequently the
sun's horizontal parallax. I drew up a monitum of this
appearance, and sent it with a letter to Mr. Oldenburg,
who printed it in his Transactions, No. 86, August 19th,
1672: having before sent my admonition into France, where
the gentlemen of their Accademy took care to have it ob-
served in several places. My father's affairs caused me to
take a journey into Lancashire, the very day I had designed
to begin my observations : but God's Providence so ordered
it that they gave me an opportunity to visit Townley, where
I was kindly received and entertained by Mr. Townley, with
whose instruments I saw Mars near the middlemost of the
three adjacent fixed stars. My stay in Lancashire was short :
at my return from thence, I took his distances from two of
them at distant times of the night. Whence I determined
his parallax then 25 ", equal to his visible diameter ; which
therefore must be its constant measure; and consequently
the sun's horizontal parallax not more than 10". This I
gave notice of in the Transactions, No. 96 : and the French,

1835.] First Astroiwmer-RoyuL 409

soon after, declared that from their observations they had
found the same. Whether they will give such exactness, I
leave to those who are skilful in these things to determine.

It was this year that the French sent Monsieur Richer to
observe the southern fixed stars at Cayenne ; where he also
observed this transit of Mars amongst the three fixed stars
in the water of Aquarius. His observations are printed i^n
the Voyages Astronomiques ; from whence I have transcribed
them to be printed after my own in the end of this Preface.
I have altered the method in which they are published, pur-
posely to bring them into less room and better order for
the service of those that have occasion to make use of them.

In the same Transactions are printed some observations
of the greatest elongations of Jupiter's satellites from him ;
whereby the diameters of their orbits were determined in
such parts as Jupiter's is one. These I found larger than
Signor Cassini had determined them, in his Satellite Tables,
1668 : but I suspect them less than the real truth, by reason
that the diameter of the planet appears bigger than it is, by
reason of the breadth of the pupil of the eye.

In the month of March of the following year, 1673, from
the observations of Jupiter's distances from the 9th of Virgo,
or the last of the four in the left wing, I determined the
greatest inclination of the orbit of Jupiter to be less than
the latitude of this star, by 26' 40'. Its latitude in my new
catalogue, is 1° 46' 10" south : whence the greatest inclina-
tion of his orbit will be 1° 19' 30". These observations,
with the process whereby it was determined, were printed
by Mr. Oldenburg in his Transactions, No. 94, for May 19,
1673.

It was this year also, as I remember, I wrote a small
tract in English, concerning the true diameters of all the
planets, and their visible, when at their nearest distance
from our earth, or their greatest remove from it ; which I
sent to Mr. Newton in the year 1685, who has made use
of it in the 4th book of his Principia.

From some observations of the eclipses of Jupiter's Satel-
lites made this year, their mean motions were corrected by
me: those of M. Cassini published in the year 1668, and
imparted to me by Mr. Townley, having showed themselves
very faulty.

410 Life of the Rev. John Flamsteed, [Dec.

Sir Jonas Moore sometimes wrote to me ; and, in his
letters, testified the pleasure he took in the success of my
endeavours, and in what I imparted to Mr. Oldenburg, and
was printed by him in the Philosophical Transactions.

By Mr. Oldenburg's means I changed some letters with
M. Cassini. Having no longer glasses yet than of thirteen
feet, I had not taken notice that the body of Jupiter was
not perfectly round ; and in one of my letters affirmed that,
to me, he appeared always round, which he took notice of;
and which caused me to consider him more attentively.
And, in my view afterwards in the same glass of thirteen
feet, I saw I had reason to suspect my heedless assertion ;
and, when I came to employ longer glasses, that he was
(as Cassini had asserted) oval.

Besides the observations I imparted to Mr. Oldenburg,
I took others that might be of use to me afterwards : though,
because the times were not so accurate as I thought was
requisite, I did not publish them.

In 1673, besides my usual task, I wrote an Ephemeris,
wherein I showed the falsity of Astrology, and the ignorance
of those who pretended to it : wherein I gave a table of the
moon's risings and settings, carefully calculated ; together
with the eclipses and appulses of the moon and planets to
fixed stars. This fell into the hands of Sir Jonas Moore,
for whom (at his request) I made a table of the moon's true
southings for that year. From which, and Mr. Phillip's
theory of the tides, the high-water being made, he found
they showed the times of the turn of the tides very near :
whereas the ordinary seamens coarse rules would err some-
times two or three hours. It was the summer of the follow-
ing year, 1674, that I came to London, in my way to Cam-
bridge ; whither Sir Jonas Moore (hearing of my intent)
invited me, and where he received me very kindly : told
me how acceptable a true account of the Tides would be to
his then Majesty King Charles II. ; off*ered me the help of
his servant to make this table or any other work of the like
nature. We resolved together to compose a small ephe-
meris for his Majesty's use : which was set upon, and in
good part finished, before Midsummer ; but not completed
till near Christmas after, by reason that I returned to Derby
about Michaelmas.

1835.] First Astronomer- Royal. 411

[* Flamsteed states that Sir Jonas was acquainted with the
attention which he had paid to the barometer, as an indica-
tor of the state of the weather, as well as to the thermometer
filled with tinged spirit, of both of which he had kept a
register three times a-day, at Derby, and requested him to
set up a pair of these glasses for his use. This Flamsteed
did, and gained the favour of the King and the Duke of
York through the candour of Sir Jonas.

Having taken his degree of A.M. at Cambridge, he de-
signed to take orders and settle in a small living near
Derby, in the gift of a friend; but his intention having
reached Sir Jonas Moore, he was prevailed on to return to
the house of the latter, February 2, 1674-75, where he met
with a kind reception. In consequence of a disagreement
with the son of Sir Jonas, in whose favour the latter had
resigned his place, Flamsteed persisted in his resolution to
take Orders. Sir Jonas, on the 4th March, brought him a
warrant designing him the King's Astronomer, " with the
allowance of only £100. per annum, payable by the Office
of Ordnance." On the Easter following he took Orders,
at Ely House, at the hands of Bishop Gunning.]

Betwixt my coming up to London, and Easter, an acci-
dent happened that hastened, if it did not occasion the
building of the Observatory. A Frenchman that called
himself Le Sieur de St. Pierre, having some small skill in
astronomy, and made an interest with a French lady, then
in favour at Court, proposed no less than the discovery of
the Longitude : and had procured a kind of Commission
from the King, to the Lord Brouncker, Dr. Ward (Bishop
of Salisbury), Sir Christopher Wren, Sir Charles Scar-
borough, Sir Jonas Moore, Col. Titus, Dr. Pell, Sir Robert
Murray, Mr. Hook, and some other ingenious gentlemen
about the town and Court, to receive his proposals ; with
power to elect, and to receive into their number, any other
skilful persons : and, having heard them, to give the King
an account of them, with their opinion whether or no they
were practicable, and would show what he pretended. Sir
Jonas Moore carried me with him to one of their meetings,
where I was chosen into their number; and, after, the
Frenchman's proposals were read : which were

* The portions enclosed by brackets are abridged. — Edit.

412 Life of the Rev, John Flamsteed, [Dec.

1°. To have the year and day of the observations :

2°. The height of two stars, and on vrhich side of the
meridian they appeared :

3°. The height of the moon's two limbs :

4°. The height of the pole : — All to degrees and minutes.

It was easy to perceive, from these demands, that the
Sieur understood not that the best lunar tables differed from
the heavens ; and that therefore his demands were not suf-
ficient for determining the longitude of the place, where
such observations were, or should be, made, from that to
which the lunar tables were fitted : which I represented
immediately to the company. But they, considering the
interest of his patroness at Court, desired to have him fur-
nished according to his demands. I undertook it ; and
having gained the moon's true place, by observations made
at Derby, Feb. 23, 1672, and Nov. 12, 1673, gave him
observations such as he demanded. The half-skilled man
did not think they could have been given him ; but cun-
ningly answered they were feigned. I delivered them to
Dr. Pell, Feb. 19, 1674-5 ; who returning me his answer
some time after, I wrote a letter in English to the Com-
missioners, and another in Latin to the Sieur, to assure him
they were not feigned ; and to show them that, if they had
been, yet if we had astronomical tables that would give us
the two places of the fixed stars and the moon's true places,
both in longitude and latitude, nearer than to half a minute,
we might hope to find the longitude of places by lunar
observations, but not by such as he demanded. But, that
we were so far from having the places of the fixed stars
true, that the Tychonic catalogues often erred ten minutes
or more : that they were uncertain to three or four minutes,
by reason that Tycho assumed a faulty obliquity of the
ecliptic, and had employed only plain sights in his observa-
tions : and that the best lunar tables differ one-quarter, if
not one- third, of a degree from the heavens : and lastly that
he might have learnt better methods than he proposed, from
his countryman Morinus, whom he had best consult before
he made any more demands of this nature. I heard no more
of the Frenchman after this ; but was told that, my letters
being shown King Charles, he startled at the assertion of
the fixed stars' places being false in the catalogue ; said, with

1835.] First Astronomer- Royal. 413

some vehemence, *' He must have them anew observed,
examined and corrected, for the use of his seamen ; " and
further, (when it was urged to him how necessary it was to
have a good stock of observations taken for correcting the
motions of the moon and planets), with the same earnest-
ness ** he must have it done." And when he was asked
Who could, or who should, do it? '* The person (says he)
that informs you of them." Whereupon I was appointed to
it, with the incompetent allowance aforementioned : but
with assurances, at the same time, of such further additions
as thereafter should be found requisite for carrying on the
work.

[For the site of the Observatory, Hyde Park and'Chelsea
College were proposed, but, at the suggestion of Sir Chris-
topher Wren, Greenwich Hill was chosen. The King
allowed £500, with bricks from Tilbury Fort, where there
was a spare stock, and some wood, iron, and lead from a
gatehouse which had been demolished in the Tower. In
July, he removed to Greenwich to look after the workmen.
The foundation of the building was laid 10th August, 1675,
and the roof was finished by Christmas.

While living with Sir Jonas Moore, he contrived the
large sextant of 6 feet 9 inches radius ; and Sir Jonas had
it constructed of wood at his own expense, by the Tower
smiths. The frame of the sextant was soon finished with
the axis and semicircle ; the brass limb being fitted on it
with the telescopes, and the limb screwed to carry the
moveable index gently upon the limb, by Mr. Tompion.
This was the first instrument of such a size.

Mr. Hook claims to be the inventor of the mode of
screwing the limbs of instruments ; but according to Flam-
steed, this contrivance is due to the Emperor Ferdinand.
Flamsteed now determined how many revolutions and
parts of the screw would answer to any number of degrees,
minutes and seconds. He erected a frame parallel to the
plane of the terrace at the bottom of the Hill. On this
frame the instrument was placed, and from its centre, 8762
inches were measured off towards the other end of the walk,
where a strong flat rail was placed. " Having computed
how many feet answered to a degree, he marked them off
on this rule which was made so long, as to subtend an

4lil Life of the Rev. John Flamsteed, [Dec.

angle of 5 degrees. Then br^inging the threads in the fixed
telescope to the beginning of the divisions, and forming it
close, he moved the screw, and carrying the moveable
index along the limb, noted what revolutions and parts
were marked by it, when the threads covered the divisions
of the 5 next degrees.

During the building of the Observatory, the instruments
were kept at the Queen's house, where he observed the
appulses of the moon to the planets and fixed stars. In
July and August, he took the elevation of the Observatory
from two stations in Friar's Road, and found it 182 feet
above the Thames. He was anxious for a mural arc, but
the sextant having cost more than was expected, a 10 feet
quadrant was fitted up by Mr. Hook, at the instance of Sir
Jonas Moore, but no dependence could ever be placed
on it.

When he went to reside at Greenwich, the only instru-
ments provided for him, were a sextant and two clocks.
The sextant was of iron, the limb covered with brass half
an inch thick ; its fiducial edge, by a peculiar contrivance
received a male screw fixed on the end of the moveable
index, which by the help of a crown wheel and handle it
easily turned round, and thereby carried the index gently
along the limb, and held it immoveable in any place. The
revolutions of the screw were numbered on the face of the
limb, and were readily turned into degrees and parts of a
circle, by means of a table made for that purpose, by trial at
land angles, before it was mounted on its axis and semi-
circles, in September, 1676.

In December, 1677, he took the sextant down and
divided the limb into degrees and minutes, in the mode
adopted by Hevelius and Tycho. His pendulum clocks
were made by Mr. Tompion, the pendulums 13 feet long
made one vibration in two seconds, and their weights re-
quired to be drawn up only once in twelve months. He
had a quadrant to rectify these, with which he could
take the sun or a star's height so exactly, as to be within
10" of the clock. This quadrant he used till June, 1678,
when Sir Jonas Moore procured him one from the Royal
Society, which he employed till October, 1679, " when the
ill nature of Mr. Hook forced it out of his hands." This

1835.] First Astronomer-Royal. 415

obliged him to construct one of his own, of 50 inches radius,
and capable of greater precision.

Besides this, he procured at his own expense, tubes and
telescope glasses of 16 and 8 feet long, to which he applied
his micrometer for observing the moon's transits, by and
over fixed stars. A large wall quadrant was at this time
made by Mr. Hook, but so clumsily, that it was of no use.
This vexed him, but he fortunately found a way of fixing
his sextant in the meridian, so as to take the greatest
heights of some stars that passed near the vertex, and
thereby ascertaining the error of the instrument, and next
took the greatest and least heights of the pole-stars. Thus,
in December, 1676, he found the simple latitude of the
Observatory, 51° 28' 50", but correct by refraction, 51°
28' 10".

In 1678, although ill, he made many observations to cor-
rect the earth's motion, (without the true knowledge either
of the obliquity of the ecliptic, or the exact places of the
fixed stars) by determining " the Sun's distances from Ve-
nus, hers from fixed stars and their meridional distances
from the vertex." The tables he had made from Tycho and
Cassini's observations, gave the greatest equation of her
orbit 8' less than Kepler's. To settle the question, in 1679,
he took the longitude of the bright star of Aries, from
Tycho's catalogue, and reduced it to that year, by allowing
50" for the annual precession ; the latitude vras corrected
by the meridional height taken with the sextant. The
places of other stars required were corrected from these
data. The tables were finished in the Spring. On the 27th
August, 1679, Sir Jonas Moore died at Godalming, in Surrey,
with whom fell all Flamsteed's hopes for having any allow-
ance granted for increasing the number of his instruments.
Sir Jonas left a book in the press for the use of Christ
Church Hospital, which was finished by Perkins and Flam-
steed ; the former of whom wrote in it the Navigation, and
the latter the Doctrine of the Sphere. This labour being over,
in 1681 he prosecuted his observations for rectifying the
places of the fixed stars and planets motions, but he found
that he could not determine the true longitude of the equi-
noctial points, from the fixed stars, without a fixed instru-
ment for determining their distances from the pole of the

416 Life of the Rev. John Flamsteed, [Dec.

world. He, therefore, (desparing of any assistance from
the King) resolved to make a large mural arc, at his own
expense, notwithstanding the " narrowness of his salary."
The instrument was completed in the course of the year ;
yet, from the coarseness of the workmanship, it lay by him
for the next year ; but, on the following, he brought it very
near the pole ; fixed it there, and divided the limb beyond
the pole. This was an arc of 140°, so contrived that all the
stars which are visible in our horizon might be observed on
it with the same index. The fault of the instrument was,
that in many parts of the limb the index did not apply
closely to it, in consequence of its warping; but he con-
ceives that this would not prejudice his observations to any
extent. Desirous of continuing his researches, he observes,
*' May the Author of the Universe, the all wise disposer of
the Heavenly bodies, assist me in the undertaking. May
He grant me health and leisure to accomplish it, and render
my ideas of his works agreeable to the Prototype, that man-
kind may have the use, and He the glory of my labours."

In 1683 he contrived and built a mural arc of so many
degrees that it might take in all the stars that passed be-
tween the pole and the south intersection of the meridian
and horizon, and likewise the pole star itself under the pole,
(that is of about 130° in the limb) and fixed it on a wall.
With this instrument he took the distances of the sun and
planets from the vertex, till the autumn of 1686.

After the death of Sir Jonas Moore, in 1679, and the
King, in 1684, he lost all hope of any allowance for instru-
ments, and was made uneasy by persons desiring to have
his observations published.

In 1687 he completed his Catalogue of 130 fixed stars.
Then his father died, and left him some property. The
first use he made of this increase to his estate was to build
a strong mural arc, as he had long before designed.

He communicated his intention to Lord Dartmouth,
Master of the Ordnance, who kindly assured him that
what he had laid out would be re-paid by the Office. His
servant, Staff'ord, who had the care of the work, died in
1688, and was succeeded by A. Sharp, an excellent geome-
trician, ready calculator, and a most expert and curious
mechanic. In autumn, Sharp set to work on the arc,

1835.] First Astronomer- Royal. 317

screwed the edge of the limb ; prepared the index ; fas-
tened the arc on the wall ; planed it anew, which cost three
months labour, and then it was rectified, divided and en-
graved by his hand. It was finished in October, 1689, after
fourteen months work, and a personal expense to Flam-
steed of £100. He found his observations greatly facili-
tated by the possession of this arc, as it required only one
assistant; whereas, with the sextant, two were scarcely
sufficient. With the sextant, in the open air, he could not
see some small stars of the 6th light ; while, with the arc,
through a slit 1| foot wide, he could see stars of the 7th
light plainly with the naked eye. His synopses of the places
of the moon were communicated to Newton.

In January 1694, having collected all his observations of
the pole star into one synopsis, he was surprised to find
that its distances from the pole were always bigger in
March, April, July, August, and September, than in De-
cember. He attributed it to the parallax of the earth's
orb being sensible in the pole star. While investigating
the inequalities of the earth's orbit, and the place of the
aphelion, he determined the right ascensions of about forty
fixed stars.

In 1676 Sir Jonas Moore gave him the sextant, some
books and glasses, with charge to dispose of them by his
will. All the other instruments and tables were provided
at his own expense.

In December 12th, 1680, he first observed .the great
comet, and noticed it till February 5, 1680-1. In 1681 he
imparted his observations on the comet to Sir Isaac Newton,
as a friend ; and in 1685, or 86, gave him the diameters of
the planets in all portions of the earth, and then in their
orbits, and got them back again with much difliculty, after
two years detention. Newton disputed against the comets of
November and December being the same, in two long letters
in February and March 1681 ; but in 1685 owned they
might be as Flamsteed asserted, and " slightly men-
tioned me as disputing for their being the same in the 4th
book of his Principia : Whereas, I affirmed it and himself
disputed against it." 1688, the Principia published. Little
notice taken of the Queen's Observatory. 1687. He built
a strong mural arc for £120, by which the places of 3000

VOL. 11, 2 E

418 Life of the Rev. John Flamsteed, [Dec.

stars were calculated; and, besides, 1000 places of the
moon, and 1000 places of the planets. " 1689. Began obser-
vations of the stars' distances from our vertex with it, — got
the clock removed."]

1694, Saturday September 1st. Mr Newton came to visit
me. Esteeming him an obliged friend, I showed him about
150 places of the moon, derived from my observations and
tables by myself, and servants hired at my own expense ;
with the differences or errors, in three synopses written on
large sheets of paper, in order to correct the theory of her
motions. On his earnest request I lent them to him, and
allowed him to take copies of them (as I did not doubt but
that by their help he would be able to correct the lunar
theory), upon these two conditions however : 1°. That he
should not impart or communicate them to anybody with-
out my consent : for the places of the moon deduced from
the observations (I told him) were got with the help of a
small catalogue of fixed stars made from observations taken
with the sextant only, and rectified to the beginning of the
year 1686 ; whereby I found their places were not so correct
as they ought to be ; and that when the stars were rectified
by the new instrument, I would calculate the moon's places
anew, and then should be ready to impart them both to him
and to the public. 2°. That he should not in the first
instance impart the result of what he derived from them
to anybody but myself: for, since I saved him all the labor
of calculating the moon's place both from the observations
and tables, it was not just that he should give the result of
my pains (the correction of the theory I had furnished with
numbers) to any other but myself. All this he approved ;
and by a letter of his dated confessed. Nevertheless

he imparted what he derived from them, both to Dr.
Gregory and Mr. Halley, contra datam Jidem. The first of
these conditions I was not much concerned whether he
kept or not : but he has, I believe, kept it. The latter
(which was the most material) he has forgot or broke ;
through the insinuation, I fear, of some persons that were
little his friends, till they saw what friends he had in the
Government ; and I presume will be less so, when they see
them laid aside.

I had thus hoped to have gained leisure to begin my

1835.] First Astronomer- Royal, ^

Catalogue of the fixed stars; for which I was now furnished
with a stock of observations, sufficient for a beginning. In
order to which the following year I made new tables for
finding the sun's true place. But I found myself soon
deceived : for instead of saving me labour, this brought
more upon me. Mr. Newton frequently called upon me
for new observations of the moon : whilst some of his crea-
tures in town cried up his success in correcting the lunar
theory ; but said not one word of his obligations or debt to
the Royal Observatory. And one of them publicly gave
out that all my pains would be well employed to so serve
him. When I demanded therefore the performance of his
promise, I was put off with excuses and delays, and some-
times even with injuries. Nevertheless, I continued to
supply his demands, as my other employment of observing
(that I might enlarge my stock for carrying on my Cata-
logue) would permit: for, at the same time, I had the resti-
tution of the sun's motions, besides my night-work, on my
hands.

This request of Mr. Newton for more observations, caused
an intercourse of letters between us, wherein I imparted to
him about 100 more of the moon's places ; which was more
than he could reasonably expect from one in my circum-
stances of constant business and ill health. The year
following (1695) I was ill all the year with a periodical
head-ache : which was carried off in September by a violent
fit of my dreadful distemper, the stone. In the mean time,
frequent letters passed between me and Mr. Newton, who
ceased not to importune me (though he was informed of my
illness) for more observations ; and with that earnestness
that looked as if he had a right to demand them ; and had
about 50 more imparted to him. But I did not think my-
self obliged to employ my pains to serve a person that was
so inconsiderate as to presume he had a right to that which
was only a courtesy. And I therefore went on with my
business of the fixed stars ; leaving Mr. Newton to examine
the lunar observations over again : which had he done, he
had found that he needed not be so importunate for new,—
the old would have been sufficient for the purpose and de-
sign for which I had imparted them to him. I was there-
fore forced to leave off my correspondence with him at that

2 B 2

420 Life of the Rev. John Flamsteed, [Dec.

time ; having found that his correction of my numbers still
gave the moon's places 8 or 9 minutes erroneous : though
Dr. Gregory and Dr. Halley had boasted they would agree
within 2 or 3 minutes.

1695, or 1696. Sir Isaac Newton, being made an officer
of the Mint, came to London. I sometimes visited there,
or at his own house in Jermyn Street. We continued civil :
but he was not so friendly as formerly, because I could not
[confirm] Mr. Halley's and Dr. Gregory's assertions con-
cerning his corrections of the Horroxian lunar theory.

[1696. Flamsteed corresponded with Mr. Bossley, apo-
thecary at Bakewell, and Mr. Luke Leigh, a poor kinsman
of Mr. Halley's. He hired Mr. Leigh to calculate ih.^ places
of the fixed stars, from their right ascensions and distances
from the north pole, determined by himself. He hired
other persons for the same purpose, and obtained a third
likewise. He employed Mr. Weston to draw charts of his
constellations. In 1696 he obtained from Mr. Leigh the
places of the stars in Gemini Cancer and Leo ; and till 1701
and 1708, the places of many others : his servants, Hodgson,
Wooferman, and I. Crosthwait assisting in the calculations,
as well as Mr. Ryley, in addition to those mentioned. In
the mean time, as often as he met Sir Isaae Newton, the
latter was very inquisitive how the Catalogue went on : — •
** I answered as it stood ; and when he came here commonly
shewed him how it stood in the books, not suspecting any
design, but hoping he might serve me as kindly as I had
assisted him freely with my pains when he desired me."

In 1698 the Czar of Muscovy visited the Observatory four
times. By 1703 he had finished all but the constellation of
Hercules ; the Great Bear, and such as lay within 30° of
the north pole.]

1704, Tuesday, April 11th. Mr. Newton came to the
Observatory ; dined with me ; saw the volume of observa-
tions ; so much of the catalogue as was then finished ; with
the charts of the constellations, both T. W.'s and those
copied by Vansommec ; desired to have the recommending
of them to the Prince. I knew his temper; that he would
be my friend no further than to serve his own ends : and
that he was spiteful, and swayed by those that were worse
than himself. This made me refuse him. However, when

1835.] First Astronomer- Royal. 421

he went away he promised he would recommed them; though
he never intended me any good by it, but to get me under
him, that I might be obliged to cry him up as E. H[alley]
has done hitherto.

1704, November 8th. Wrote the estimate, which was
read without my knowledge at the Royal Society. The
members thought it ought to be recommended to the Prince :
the President joined with them : a committee was appointed
to attend his Royal Highness : done without acquainting
me with it : an estimate of the charge drawn up without my
knowledge: the Prince allows £1200: Mr. Newton says
£1100. He concludes me now in his power; does all he
can to hinder the work, or spoil it, by encouraging the
printer to commit faults. We must print the observations ;
though I had showed in my printed estimate that, for very
good reasons, the charts of the constellations ought first to
be set upon.

Mr. Newton told me he hoped I would give a note, under
my hand, of security for the Prince's money. This I know
was to oblige me to be his slave. I answered that I had
(God be thanked) some estate of my own, which I hoped
to leave, for my wife's support, to her during her life, to
my own relations afterwards : that therefore I would not
cumber my own estate with impress or security: but if
they would please to take his Royal Highness's money into
their hands, I would sign the workmen's bills to them,
whereby they would see if they were reasonable at the same
time. I was told, I should have all the printed copies, save
what his Royal Highness should have to present to the
Universities. And Mr. Newton granted that, since I re-
fused to handle any of his Royal Highness's money, there
was no need of security or articles : nevertheless . .

[Here this MS ends abruptly.]

Whilst Mr. Flamsteed was busied in the laborious work
of the Catalogue of the fixed stars, and forced often to
watch and labour by night, to fetch the materials for it from
the heavens, that were to be employed by day, he often, on
Sir Isaac Newton's instances, furnished him with observa-
tions of the moon's places, in order to carry on his correc-
tion of the lunar theory. A civil correspondence was
carried on between them : only Mr. Flamsteed could not

422 Life of the Rev. John Flamsteed, [Dec.

but take notice, that as Sir Isaac was advanced in place, so
he raised himself in his conversation, and became more
magisterial. At last, finding that Mr. Flamsteed had ad-
vanced far in his designed Catalogue, by the help of his
country calculators, that he had made new lunar tables, and
was daily advancing on the other planets, Sir Isaac Newton
came to see him (Tuesday, April 11, 1704); and desiring,
after dinner, to be shown in what forwardness his work was,
had so much of the catalogue of the fixed stars laid open be-
fore him as was then finished ; together with the maps of the
constellations ; both those drawn by T. Weston and P. Van
Sommer, as also his collation of the observed places of
Saturn and Jupiter with the Rudolphine numbers. Having
viewed them well, he told Mr. Flamsteed he would (i. e. he
was desirous to) recommend them to the Prince privately .
Mr. Flamsteed (who had long been sensible of his partiality,
and heard how his two flatterers cried Sir Isaac's perform-
ances up, was sensible of the snare in the word privately)
answered that would not do : and (upon Sir Isaac's demand-
ing ** why not ?") that then the Prince's attendants would
tell him these were but curiosities of no great use, and
persuade him to save that expense, that there might be the
more for them to beg of him : and that the recommendation
must be made publicly to prevent any such suggestions.
Sir Isaac apprehended right, that he was understood, and
his design defeated : and so took his leave not well satisfied
with the refusal.

It was November following ere Mr. Flamsteed heard
from him any more : when, considering with himself that
what he had done was not well understood, he set himself
to examine how many folio pages his work when printed
would fill ; and found upon an easy computation that they
would at least take up 1400. Being amazed at this, he set
himself to consider them more seriously ; drew up an es-
timate of them : and to obviate the misrepresentations of
Dr. S [loane] and some others, who had given out that
what he had was inconsiderable, he delivered a copy of the
estimate to Mr. Hodgson, then lately chosen a Member of
the Royal Society, with directions to deliver it to a friend,
who he knew would do him justice ; and, on this fair ac-
count, obviate those unjust reports which had been studi-

1835.] First Astronomer-Royal 423

ously spread to his prejudice. It happened soon after, Mr.
Hodgson being at a meeting spied this person there, at
the other side of the room ; and therefore gave the paper
to one, that stood in some company betwixt them, to be
handed to him. But the gentleman, mistaking his request,
handed it to the Secretary [Dr. Sloane] who, being a Physi-
cian, and not acquainted with astronomical terms, did not
read it readily. Whereupon another in the company took
it out of his hands; and, having read it distinctly, desired
that the works therein mentioned might be recommended
to the Prince : the charge of printing them being too great
either for the author or the Royal Society. Sir Isaac closed
in with this.

[Here ends the document from which the above portion
of the history is taken.]

I had been acquainted with Mr. Newton ever since the
year 1674; had given him the diameters of the planets
observed by me at Derby in the years 1671, 72, and 73 ; as
also the greatest elongations of Jupiter's satellites ( of both
which he made use in his Principia) ; and, since I came to
London, the line of the great comet of the years 1680 and
81 ; affirming that the comet which was seen in November
before was the same with that I observed in the following
December : which he would not then grant, but contended
earnestly that they were two different ones, as appears by a
couple of very long letters of his to me, dated Feb. 28,
1680-1, and April 16, 1681. In which opinion he persisted
till September 1685 ; when, in a letter dated the 19th of
that month, he writes, " I have not yet computed the orbit
of a comet, but am now going about it, and taking that of
1680 into fresh consideration. It seems very probable that
those of November and December were the same comet.'*
This is what he before contended against with some viru-
lency, but he had no mind to remember it, and at that time
I took no great notice of it, till I found when his Principia
were published in 1687, and therein a draught of the comet's
orbit, he was pleased to acknowledge that I had disputed
that the comets seen in November and December were one
and the same ; and that I had given him the line of its way
not much different from his parabolical one there described.
Whereas himself had disputed against their being one, and

424 Life of the Rev. John Flamsteed, [Dec.

consequently against that one describing any parabolic line
as he now asserted, and will appear by his own foremen-
tioned letters to me. From this time till the year 1695, we
corresponded civilly ; especially about the years 1694 and
1695, when, on his repeated requests, I imparted to him
about 150 places of the moon deduced from observations
made with the mural arch, and compared with my own
tables, fitted to Mr. Horrocks's theory; but covenanted at
the same time that he should not impart them to anybody
without my consent. For, I told him (and he knew it very
well) that I had made use of an old catalogue of the fixed
stars, made to the beginning of the year 1686, from obser-
vations taken with the sextant : that I was busy now with a
better and more convenient instrument ; and that, as soon
as I had got the new catalogue, I intended, perfected, all
those places of the moon should be calculated over again,
and imparted to him : but the hopes he had of making that
theory his own, and the glory of restoring the moon's mo-
tions, would not suj9fer him to stay so long for.

It was not a full year after but I was told that he had
perfected the lunar theory : and Dr. Gregory gave out
that there was no need for further observations ; for his
aumber would answer all my observations within two
or three minutes, or less. I had covenanted with him
to have his emendations first imparted to me, because
I imparted to him the observations from which they
were derived. But, his promise was overlooked or for-
got : at last it came to my hands. I found the solar
numbers were the same I had freely given him : and the
lunar but little altered ; save that he had added a parcel of
very small equations which, whether the heavens would
bear or not, was only to be found by comparing his numbers
with good observations. I therefore made new lunar tables
exactly agreeable to his sentiment : but when I compared
the moon's places, calculated from them, with her places
deduced from the observations, I found that those numbers
which were said to agree with the observations within two
or three minutes, would very seldom come so near, but
often differed 7, 9, or 10 minutes; which I did not admire
then at all, being very sensible that the persons who so
loudly on all occasions cried up his performances in amend-

1835.] First Astronomer- Roy aL 425

ing the lunar theory and tables, did it to oblige his friend-
ship, who had then a great interest in a great courtier :
and considering also that [they] were persons of very ordi-
nary skill in that part of mathematics which was concerned
with the heavens and the lunar theory.
( To he continued.)

Article II.

Mesearches into the Nature of the Decolourizing Combinations

of Chlorine. By A. J. Balard.

C Concluded from p. 35 1. J

Composition of Chlorous Acid.
The experiments which have been detailed prove that
chlorous acid consists of chlorine and oxygen, but they do
not determine the proportions in which these elements are
united. Further researches were necessary for this purpose.
Several methods of analyzing chlorous acid diluted with
water present themselves. It may, for example, be decom-
posed by a combustible, which will liberate the chlorine ;
when the proportion of this gas and the oxygen combined
with it may be determined ; or the acid may be treated by
metallic silver, and the products of oxygen and chloride of
silver collected. But, by each of these methods, only one
of the elements of the acid is procured in a gaseous state.
It is necessary to determine the volume of the other by
weighing and calculation which renders the analytical pro-
cess very tedious. It was necessary, therefore, to endeavour
to fall upon a method by which the elements would be
obtained in the form of a gaseous mixture. The action
which chlorous acid exercises upon oxalic acid appeared to
present an easy process. We know that oxalic acid, when
decomposed, is resolved into carbonic acid and carbonic
oxide, and that this last compound requires the half of its
volume of oxygen to change it into a volume of carbonic
acid equal to its own. Hence, it results that when oxalic
acid is converted into carbonic acid gas, the fourth of the
gas obtained represents that of the additional oxygen which
was required to produce this change.
The analysis of chlorous acid is thus resolved into the

426 M. Balard on the Nature of the [Dec.

separation of chlorine and carbonic acid, which is easily
accomplished by means of mercury. Various trials were
made in this way, which, although all indicating that the
volume of the chlorine was almost double that of the oxygen,
differed, however, too much from this result, which was so
various as to diminish my confidence in it.

Convinced, however, that it was not owing to errors in
experiments that these different results were obtained ; the
liquid being tested with nitrate of silver, after a decomposi-
tion of this kind, it was proved that some of the chlorine
was retained in the liquid. It was clear that the quantity
retained increased in proportion as the acid was more
diluted. It is not certain in what state the chlorine exists
in the liquid ; perhaps it may be in the form of chloroxalic
acid, which Dumas formed by exposing acetic acid and
chlorine to the action of the solar rays. Perhaps, also, it
may be in the state of muriatic acid, which might be formed
by the decomposition of the acid, carbonic acid being dis-
engaged. Inaccurate as this method is, it appears to prove
that chlorous acid is composed of two volumes chlorine
and one of oxygen. But its action with muriatic acid dissi-
pates any doubt on this head. Chlorous and muriatic acids
produce, by double decomposition, as has been already
stated, water and chlorine. Now, if upon a given quantity
of muriatic acid, an excess of chlorous acid is allowed to act,
the proportion between the volumes of the acid gas decom-
posed, and of the chlorine obtained, may enable us to deduce
the composition of the chlorous acid from that of the muri-
atic itself.

This decomposition was attempted, either by passing
muriatic acid gas over mercury, in a graduated tube, con-
taining at its upper part, a small portion of very concen-
trated chlorous acid,"*^' or by introducing chlorous acid into
a tube already containing some muriatic acid gas. But the
decomposition in both cases was very imperfect. The fol-
lowing method, however, succeeded well : —

Having filled, over a mercurial trough, a flask ground
with emery, with dry muriatic acid gas, a small glass globe

• For the complete decomposition of these two acids, it is necessary that the
chlorous acid be very concentrated, because they may co-exist without decom-
posing each other when they are in a certain state of dilution.

1835.] Decolourizing Combinations of Chlorine. 427

filled with chlorous acid, and hermetically sealed, was in-
troduced into it. The flask was closed, and then agitated
so as to break the globe. When the chlorous and muriatic
acid came in contact, the decomposition took place with dis-
engagement of heat, and the interior of the flask assumed
a yellow colour. When the latter was preserved at the
temperature of the atmosphere, it was opened over mercury,
without a single drop of the liquid entering, or a bubble of
the gas escaping. The gas which filled it was completely
absorbed by the mercury. Muriatic acid, in its decomposi-
tion by chlorous acid, is transformed into a volume of chlo-
rine exactly equal to itself. Now, in this volume of muri-
atic acid, there was half a volume of hydrogen ; the chlo-
rous acid which had changed this hydrogen, into water,
had, therefore, yielded a fourth of its volume of oxygen.
On the other hand, the decomposed muriatic acid could
only give half a volume of chlorine, and as a whole volume
had been produced, the other half volume must have been
furnished by the chlorous acid. The latter was, therefore,
obviously, composed of two volumes of chlorine and one
volume of oxygen.

It was possible, however, that this method of analysis,
which appears as simple as it is elegant, might have been
vitiated by a single circumstance, viz. that the heat deve-
loped might have disengaged, in the gaseous form, a portion
of chlorous acid, which would be completely absorbed by
the mercury. The gas disengaged would not, therefore,
be equal to that of the muriatic acid employed.

It had been noticed that concentrated sulphuric acid, in
acting upon liquid chlorous acid, disengaged, besides pure
chlorous acid, gaseous products. It was considered proper
to determine in what proportion chlorine and oxygen were
disengaged. For this purpose, 50 parts, by volume, of this
gas, were submitted to the action of heat,in order to produce
detonation ; 72 parts were the result, which, on being
treated by an alkaline solution, were reduced to 25 parts
oxygen gas.

If allowance is made for the mode of experiment in which
a small portion of the chlorine is necessarily absorbed by
the mercury, the loss sustained is easily accounted for :

428 M, Balard on the Nature of the [Dec.

and we may conclude, from this as well as the preceding
experiments, that chlorous acid is composed of two volumes
of chlorine and one of oxygen. In another experiment, by
detonation, from 45 parts of the gas, 69 parts of a gaseous
mixture were obtained, which were reduced to 23 parts on
being agitated with an alkaline solution. This result not
only justifies the correctness of the other experiments, but it
enables us to appreciate the condensation which the chlo-
rine and oxygen undergo when they unite to form chlorous
acid.

We see that this condensation is one-third of the whole
volume, and equal to that of the oxygen which enters into
its composition.

The analysis of chlorous acid proves its composition to be
the same as the gas obtained by the chlorate of potash and
muriatic acid, which chemists have long considered as the
protoxide of chlorine. If it should be demonstrated that
this product is really distinct, as it differs much from chlo-
rous acid, which has been described, these two bodies will
afford a new example of isomerism. But the researches of
Soubeiran have rendered it probable that the protoxide is a
mixture of chlorine and deutoxide of chlorine. The com-
position of chlorous acid, as before deduced, differs much
from that assigned to it by chemists. Liebig, in determin-
ing the action of the decolourizing compounds of chlorine
upon the sulphurets of barium, lead, &c., has found them
immediately, changed into sulphurets, without disengage-
ment of chlorine or precipitation of sulphur.

Now, in order to change one atom of these sulphurets
into a sulphate, four atoms of oxygen are necessary, three
to form the acid and one to form the base. Liebig supposed
that this effect was produced by one atom of chlorite ; and,
as the base of this chlorite could have only yielded one
atom, he concluded that the three were furnished by the
chlorous acid. On the other hand, the atom of the metallic
base exists in the liquid in the state of muriate ; two atoms
of chlorine are therefore required to form this compound.

Chlorous acid would appear, therefore, to consist of two
atoms chlorine and three of oxygen. But we have only to
suppose that two atoms of this acid were required to convert

1835.] Decolourizing Combinations of Chlorine, 429

one atom of the sulphuret into a sulphate, and the observa-
tions detailed here, and those of Liebig will be found to
agree. Of the four atoms of oxygen required, two will be
furnished by the two atoms of acid, and the other two by
the two atoms of the base ; and the four atoms of chlorine
combining with two atoms of the metal, two atoms of chlo-
ride will be formed.

M. Soubeiran has arrived at the same results as Liebig,
by the following considerations : —

If chlorous acid possesses the composition which chemists
suppose it has, it is necessary that, in its production, three
atoms of metallic oxide be decomposed in order to furnish
the three atoms of oxygen which enter into its composition.
Hence, three atoms of metallic chloride are formed, and
the decolourizing compounds of chlorine ought to consist of
three atoms of chloride and one atom chlorite.

To verify this supposition, Soubeiran converted a solution
containing four atoms of soda into a decolourizing chloride.
This solution was evaporated in a vacuum, and the residue
treated with a saturated solution of common salt, so as to
dissolve the chlorite and leave the chloride. He found the
chloride of sodium equivalent to 2*1 atoms of soda; and,
with rather too great an allowance, he concluded that this
2*1 atoms were equivalent to three; and, therefore, that
chlorous acid is probably composed of two atoms chlorine
+ three oxygen.

If we consider that, in a similar mode of operating, the
quantity of metallic chloride obtained was rather greater
than inferred, to that which was first formed by the re-action
of the chloride upon the soda, we can scarcely doubt that
the 2*1 atoms ought rather to be considered two atoms,
which would establish an exact agreement between the
results detailed in this paper and those of Soubeiran.

M. Morin, in his Memoir upon the Decolourizing Chlo-
rides, has proved that in their decomposition, whether spon-
taneous or excited by heat, these compounds are converted
into seventeen atoms of chloride for one of chlorate, and
that there is disengaged at the same time twelve atoms of
oxygen .

Now, supposing that chlorous acid is formed of two atoms
chlorine + three oxygen, we have,

430 M, Balard on the Nature of the [Dec.

Atoms Employed.

in,. 'J i 9 atoms metal

o » ^^ '. ) 9 atoms oxide = J

9 atoms cMonte = ^ • , - M^ chlorine

( 9 ,. acid - ^ 2^

Atoms Produced.

r r 24 atoms oxygen

1 2 atoms oxide = ? 2 ,, metal
2 atoms chlorate =< C 2

^2 .. acid = J ^

7 atoms chloride = J

oxygen

chlorine

oxygen

metal

chlorine

^10

7
14

If we join to these 7 atoms of chloride the 27 which were
mixed with the 9 atoms of chlorite in the decolourizing com-
pound, we should then have 34 chloride for 2 chlorate, or
17tol.

But the supposition that chlorous acid is formed of 2
atoms chlorine + 2 oxygen, agrees also with these results.
The atomic composition may, therefore, be expressed as
follows : —

Atoms Employed.

f 9 atoms acid =ri^^t°°^«^^^^"°«
9 atoms chlorite< J I " oxygen

) 9 ,. base=5 I " "^^*^^
V. C 9 „ oxygen.

Atoms Produced.

It „ oxygen

f latomacid=^ l " ^^^^^^^^

latomcUorate< \ J " ^^^^f"

) 1 „ base=5 \ " "^^^^

V. ( 1 ,. oxygen

8 „ metal

16 ,, chlorine

8 atoms chloride = I ^ " "'^^^

The 8 atoms of chloride formed, and the 9 with which
they were mixed, (admitting that the chlorous acid pos-
sesses the composition pointed out) make up the 17 of
chloride for 1 of chlorate observed by M. Morin.

Previous experiments proved that, in the decolourizing
liquids which chlorine forms with the alkaline oxides, the
proportion of the elements is 1 atom oxygen + 2 chlorine ;
and in the hypothesis which considered the chlorine com-
bined with an oxide, the composition was expressed by

It is evident that the same relation ought always to sub-

1835.] Decolourizing Comhinations of Chlorine. 431

sist, and the number of atoms to be expressed by an entire
number. By multiplying the first formula by the entire
numbers, and arranging the atoms obtained so as to form
metallic chlorides and salts, with an oxide of chlorine, we
have the following results: —

R

+ 0 +

2 CI

X 2 =

RC12 +

Cl^ R

R

+ 0 +

2 CI

X 3 =

2RC12

+ C12

R'

R

+ 0 +

2 CI

X 4 =

: 3 R C12

+ ci^

^R

R

+ 0 +

2 CI

X 5 =

: 4 R C12

■h cv

^ R

Of these

different formulae

the third

i has

been

pre-

ferred

by i

chemists

, and

1 chlorous acid

has

been

con-

sidered similar in its composition to nitrous and sulphurous
acid. But why not admit the second, which is the most
simple, and consider chlorous acid similar to hypo-sulphur-
ous acid. Considered abstractly from all experiment, this
supposition is the most natural one, for the circumstances
in which chlorous acid is formed do not resemble those
under which phosphorous, nitrous acids, &c., are produced,
while they are identical with those which accompany the
formation of hypo-sulphurous acid. We know, indeed, that
it is in treating the alkaline oxides by sulphur, with the
access of water, that we obtain mixtures of one atom hypo-
sulphite, and one atom of hypo-sulphuret. If in this re-
action we substitute chlorine for the sulphur, we have one
atom chlorite and one atom of chloride. The only difference
between the two cases is that the number which expresses
the chemical equivalent of chlorine is double that which
expresses its atom, while, in sulphur, these two numbers
are equal. The formula of chlorous acid is Cl^, while that
of hypo-sulphurous acid is S.

It is only since Soubeiran shewed the probability that the
protoxide of chlorine of Davy is only a mixture of protoxide
and deutoxide, that we could infer apriori the true composi-
tion of chlorous acid.

What name ought to be given to this compound ? It is
evident that the term chlorous acid cannot be preserved.
It is better, therefore, to call it hypo-chlorous acid, which will
shew its analogy with hypo-sulphurous, hypo-phosphorous
acids, &c., composed of one atom of each element. The
name chlorous acid will thus be reserved for a compound
yet unknown, of 2 volumes chlorine -h 3 oxygen ; and that

432 M. Balard on the Nature of the [Dec.

of hypochloric acid, as Thenard has suggested, to the com-
pound termed at present deutoxide of chlorine.

HypO'Chlorites. — It is probable that the hypo-chlorites con-
tain chlorides mixed with them. But, as it might have
happened that the hypo-chlorous acid was formed by decom-
position, and was not present in the bodies from which it
was extracted, it was necessary to study its combinations
with the bases, and to show that they are similar to those
which exist in the decolourizing compounds.

The hypo-chlorites may be obtained pure, by direct means,
or by double decomposition.

Its direct combination with the bases is accompanied with
intense heat, which, when excessive, converts the hypo-
chlorite into chlorate and chloride. The presence of an
excess of base, however, prevents this change, while it is
very readily produced when the chlorous acid is in excess.
It is proper, therefore, to pour -upon the alkaline substance
acid insufficient for saturation, and to agitate the mixture
in a flask immersed in cold water.

With these precautions hypo-chlorite of potash may be
formed ; if they are neglected, chlorate precipitates, and
oxygen is disengaged, mixed with chlorine if the heat is
intense. The latter appearance is easily explained, because
M. Morin has proved that the decolourizing compounds of
chlorine lose oxygen when they are changed into chlorates ;
and, it has been already stated, that the metallic chlorides,
when in contact with chlorous acid, undergo a decomposi-
tion in which chlorine is given out. Now, the formation
of chlorate is always accompanied with a corresponding
production of chloride.

When the hypo-chlorites of barytes and lime have been
prepared, other salts may be formed by double decom-
position.

Potash, soda, lithia, strontia, barytes, lime, and mag-
nesia, unite with it.

M. Grouvelle had previously observed that the protoxide
of iron, oxygen of copper, and zinc, absorb this gas, and
form decolourizing compounds which are transformed by
heat into chlorine and oxides.

Hypo-chlorous acid does not dissolve the slightest quantity
of peroxide of iron, when made to act on it, as in the decom-

1835. Decolourizing Compounds of Chlorine. 433

position of hypo-chlorite of lime, by persulphate of iron,
sulphate of lime and peroxide precipitated. Chlorine is
slowly absorbed, as Grouvelle states, by hydrate of iron,
and the liquor, after ebullition for a quarter of an hour, pos-
sesses strong decolourizing properties. During the ebulli-
tion, chlorine and chlorous acid are disengaged. The liquid,
before boiling, contained a salt of peroxide of iron, but
during the distillation almost the whole of this peroxide was
deposited in a state of purity. Hence, it appears that in
the action of peroxide of iron upon chlorine, peroxide of iron
and chlorous acid are formed, compounds which may co-
exist on account of the state of dilution in which they may
both be. The intervention of heat destroys what was formed
in the cold, and induces an inverse re-action, from which
peroxide of iron and chlorine result, and some chlorous acid
escapes.

Solutions of sulphates of zinc and copper are decomposed
by hypo-sulphate of lime, while sulphate of lime, and
metallic oxide precipitate.

If the chlorate of lime is in excess, no metal remains in
solution, and hypo-chlorous acid is obtained by distillation.

When the hydrates of zinc and copper are treated by
hypo-chlorous acid, a certain quantity is dissolved, and the
liquid possesses decolourizing properties. Now, since free
chlorous acid dissolves these oxides, and these compounds
are precipitated in solutions of alkaline chlorites which
contain an excess of chlorous acid, it is natural to think
that in this case the chlorous acid does not exist free. It
is then probable that some alkaline oxides, as of lime, for
example, are capable of forming bihypo-chlorites, which de-
compose by evaporation in a vacuum, into neutral hypo-
chlorites, and hypo-chlorous acid. The hypo-chlorites of
zinc and copper are easily decomposed ; when distilled,
hypo-chlorous acid and a little oxygen pass over, and they
are changed into chlorides of oxides. The chloride of the
oxide of copper is a beautiful green; that of zinc, white.
The latter decomposes into chloride and chlorate, with dis-
engagement of oxygen, mixed with a little chlorine. These
chlorites, mixed with chlorides, may be obtained by agi-
tating with chlorine one or other of these hydrates diluted
iwith water. The gas is rapidly absorbed, especially by the

VOL. II. 2 F

-434 Jf. Balard on the Nature of the [Dec.

zinc. The distilled liquid deposits this chloride of the oxide,
and contains a metallic chloride in solution. When per-
oxide of mercury cannot be had, these oxides will serve for
preparing the acid. The hypo-chloritesof the strong bases
present the following properties : Their odour and colour
are identically the same as those of the corresponding de-
colourizing compounds of chlorine, from which it is impos-
sible to distinguish them by their physical qualities. Slight
elevation of temperature, and the influence oC solar lights
transform them into chlorates and chlorides. The propor-
tions of these salts formed were not ascertained. Sometimes
only oxygen is disengaged during the decomposition, and,,
therefore, it cannot be taken as affording a measure of the
salts formed.

The salts, with a base of potash, soda, lime, barytes, and
strontian, may be obtained in a dry state by evaporation in
vacuo, but a great excess of alkali must be added. The
hypo-chlorites are easily decomposed by acids, although
hypo-chlorous acid drives away carbonic acid from its
combinations, — it is displaced, in its turn, by a current of
carbonic acid. The hypo-chlorites readily convert sulphur,
iodine, phosphorus, and arsenic into their corresponding
acids in ic. When fragments of arsenic, blackened on their
surface by a little protoxide, are placed in a solution of
these salts they resume their metallic lustre.

Gold and platinum are not altered by the hypo-chlorites.
Silver is slowly changed into chloride, with disengagement
of oxygen. Iron oxidates very rapidly. Tin and copper
become speedily muriates. Mercury is changed into red
muriate by coming in contact with hypo-chlorite of lime.
The sulphurets are converted into sulphates by hypo-chlo-
rites; and these salts and hypo-chlorous acid may, like
peroxide of hydrogen, be employed for restoring paintings,
in which the white colour produced by carbonate of lead
has become black and been converted into a sulphuret.
The metallic protoxides are changed into peroxides, and
the salts in ite into salts in ate. Deutoxide of azote becomes
nitric acid.

The action of the pure hypo-chlorites upon ligneous mat-
ter is great. When brought in contact with filtering paper
much heat is disengaged, chloride and chlorate formed, and

1835.] Decolourizing Compounds of Chlorine. 435

the paper becomes friable, but is not charred, while oxygen
is disengaged.

The experiments of Soubeiran and Liebig shewed that
alcohol is converted by the decolourizing chlorides into a
peculiar chloride of carbon. The hypo-chlorites possess
the same property. The facts already stated justify the
following conclusions : 1. The hypo-chlorites enjoy a great
number of properties which characterize free hypo-chlorous
acid. 2. These properties are identically the same as those
which have been observed in the decolourizing chlorides,
which should be considered as consisting of 1 atom chlo-
ride 4-1 atom hypo-chlorite. 3. The presence of a metallic
chloride in the decolourizing chlorides does not alter the
properties of the hypo-chlorite itself.

It may be asked, how do these compounds decolourize
and disinfect 1 The answer is easy. — When an acid is added
to them chlorine is disengaged, and it is this chlorine which
disinfects and decolourizes, by a mode of action not yet
understood, but which is generally considered to be an
oxidation produced in an indirect manner, at the expense
of the elements of water. If they act without the aid of
acids, it is only by the oxygen of the acid and of the base
of the hypo-chlorite that they can decolourize and disinfect,
and which transforms the latter into a chloride.

A corresponding compound of bromine and oxygen, hypo-
hromous acid may be obtained by a similar proceeding.

Article III.

On Bleaching Powder.* By Thomas Thomson, M.D.,
F.R.S., L. & E., Regius Professor of Chemistry in the
University of Glasgow.

Bleaching powder has been in common use among the
bleachers and calico-printers of Great Britain for the
greatest part of the present century. The gradual diminu-

* The experiments contained in this paper were made several years ago. I
puhlish them at present, because they serve to confirm the results of M. Balard's
analysis of chlorous acid, contained in the preceding memoir.

2f2

436 Dr, Thomas Thomson, on [Dec.

tion which has taken place in its price, together with the
great improvement in its quality, has contributed very much,
indeed, to its almost universal employment. It is suffici-
ently known, that the mode of making this important article
of commerce is to expose slacked lime, in the state of a dry
powder, to an atmosphere of chlorine gas, till it ceases to
absorb it. Unslacked lime does not possess the property of
absorbing this gas.

When Mr. Dalton published his experiments on bleaching
powder, in 1813, (Annals of Philosophy, ii. 6.) he found it
a compound of 1 atom chlorine and 2 atoms lime. And
this seems to have been its usual strength about that period.
When such a powder is digested in water, only half the
the lime dissolves in combination with the chlorine ; the
other half, (abstracting the small quantity of quick lime
soluble in water) remains undissolved. But, of late years,
the strength of the powder has been so much increased that
it is nearly all soluble in water. Such powder contains one
atom of chlorine to every atom of lime in the compound.
The best bleaching powder manufactured in Glasgow is of
this quality ; and I have analyzed it from Belfast equally
strong.

It is well known that bleaching powder is white and
pulverulent. Its taste is hot, bitter, and astringent, and it
has a peculiar smell. When digested in water it always
leaves behind a little carbonate of lime, mixed with some
silica and a very little sand. These things I consider as im-
purity from the lime employed, which is never absolutely
free from foreign matter.

When bleaching powder, dissolved in water, or mixed
with water in such proportion as to be in the state of a paste,
comes in contact with sal-ammoniac, nitrate of ammonia,
oxalate of ammonia, or probably any ammoniacal salt, a
violent effervescence takes place, and azotic gas is evolved
in abundance. This evolution is occasioned by the decom-
position of the ammonia, the hydrogen of which unites with
the chlorine, (and, doubtless, also with the oxygen), con-
verting it into muriatic acid and water, while the azotic gas
is disengaged. For every atom of ammonia decomposed,
three atoms of chlorine are converted into muriatic acid.
When the solutions are too dilute, very little azotic gas is

1835.] Bleaching Powder, 437

evolved. I found the best proportion to be, to mix 100 grs.
of bleaching powder with one cubic inch of water, and then
to add the ammoniacal salt in a solid state. When the
bleaching powder is as strong as possible, 107 grs. of it are
capable of decomposing the ammonia in 100 grs. of nitrate
of ammonia. The azotic gas disengaged amounts to about
31*5 cubic inches.

As it was suspected by some foreign chemists of emi-
nence, that the chlorine in bleaching powder is not in the
state of simple chlorine, but united with oxygen, so as to
form an acid, I was anxious to put this opinion to the
test of experiment, — the only way in which chemical theo-
ries can be verified. I shall here relate, as shortly as pos-
sible, the results which I obtained : The bleaching powder
which I used was recently made, and it. was of the strongest
and best kind, manufactured by Charles Tennant & Co.,
Glasgow, the original contrivers, and still the most exten-
sive manufacturers of this article.

My method of proceeding was this : Into a small Berlin
porcelain retort, (previously weighed), 200 grs. of the
bleaching powder were put. To the beak of this retort
was luted a glass tube, about 14 inches in length, and about
an inch in internal diameter. This tube was filled with
fragments of fused chloride of calcium, which were kept in
their places by small quantities of asbestus, inserted into
each end of the tube. To the extremity of this glass tube
another bent glass tube was luted, by means of a ribbon of
caoutchouc. This tube passed to the bottom of a Wolfe's
bottle containing a solution of nitrate of silver, which very
nearly filled it. From the other mouth of the Wolfe's bottle
a glass tube passed into a pneumatic trough, to collect any
gas which might be evolved during the experiment. Heat
was now applied to the belly of the porcelain retort which
contained the bleaching powder, and was gradually raised
till the retort was red hot, and it was kept in this state till
all emission of gas was at an end. The apparatus was then
allowed to cool, and the different parts of it were detached
from each other.

The loss of weight sustained by the retort gave the whole
matter that had been driven off by the heat. The increase
of weight of the tube filled with chloride of calcium, gave

438 Dr, Thomas Thomson, on [Dec.

the quantity of water disengaged . The precipitated chloride
of silver in the Wolfe's bottle being washed, dried and fused,
gave the quantity of chlorine driven off. Finally, the vo-
lume of gas extricated was determined. It was always oxy-
gen gas.

The matter in the retort was washed out as far as possible
with water, and what the water would not dissolve was dis-
solved by nitric acid. The portion dissolved by the water
was found to be pure chloride of calcium. What was dis-
solved by the nitric acid was lime, silica, alumina, kc, for
the porcelain retort was always acted upon, and usually lost
from 12 to 13 grs. of its weight.

The experiments made were numerous, because I wished
to try the nature of bleaching powders of different strengths
and of different ages. The following are the general results :

1. The water from 200 grs. of the strongest bleaching
powder was 41*55 grs., or 20*77 per cent. When the
strength of the bleaching powder was inferior, the quantity
of water diminished. I tried some very weak powder, con-
taining more than half its lime uncombined ; the quantity
of water which it contained was only 13*35 per cent.

2. When the bleaching powder was newly made, and of
the strongest quality, the oxygen disengaged bore a constant
ratio to the chlorine. This chlorine had partly escaped in
the form of gas, and continued partly united to calcium in
the residue in the retort. For every atom of chlorine con-
tained in the powder, a corresponding atom of oxygen was
disengaged.

This result was verified by numerous repetitions. It
proves sufficiently that if the bleaching powder contains a
combination of oxygen and chlorine, it can only consist of
a combination of one atom of chlorine and one atom of
oxygen. The simplest explanation would be to consider
bleaching powder as a compound of one atom lime and one
atom chlorine. When heat is applied the chlorine displaces
the oxygen of the lime, and forms chloride of calcium.
But the researches of Balard demonstrate that there really
exists a compound of one atom chlorine and one atom oxy-
gen. It is clear, therefore, that bleaching powder is in
reality a mixture of chloride of calcium, and chlorite of
lime.

1^35.] Bleaching Powder.

I shall state the analysis of 100 grs. of a very pure bleach-
ing powder, upon which the most numerous experiments
were made : —

Matter insoluble in water 10'55 atoms.

Chlorine 38-63= 8-5 or 1-

Lime 30-05 = 8-5 „ 1-

Water ...... 20-77 = 18-4 „ 2-16

100-00
Now, the lime consisted of an atom of calcium united to
an atom of oxygen. We may, therefore, state the ultimate
constituents of bleaching powder as follows : —

1 atom chlorine , . . 4*5
1 atom oxygen . . . 1-

1 atom calcium . . . 2-5

2 atoms water . . . 2-25

10-25

But the calcium united to the chlorous acid must have
been in the state of lime. And it is quite evident (if we
suppose the bleaching powder perfectly pure) that during
the process one half of the chlorine decomposes one half of
the lime^ converting it into chloride of calcium. The oxy-
gen thus disengaged unites to the other half of the chlorine,
converting it into chlorous acid ; and this acid combines
with the other half of the lime. Hence, bleaching powder
(when as strong as possible) is composed of,

1 atom chloride of calcium . 7-
1 atom chlorite of lime . . 9-
4 atoms water 4-5

20-5
The presence of the water is essential to the formation of
the salt. Hence, it is probable that it is in combination
with the chlorite of lime.

3. When the bleaching powder is very weak -no chlorine
whatever passes over into the Wolfe's bottle. When the
powder was of the best quality the quantity which came
over was 7*3 grs. from 200 grs. of the bleaching powder.

4. When the bleaching powder was old, the quantity of
oxygen extricated, compared with that of the chlorine, was

440 An Easy Met hod of [Dec.

less than in recently made powder. For example, in a speci-
men analyzed, the atoms of chlorine in the powder were to
the atoms of oxygen, disengaged very nearly as 6 to 5. And
in other and older specimens, the chlorine bore a still higher
ratio to the oxygen. This must be owing, I conceive, to a
tendency which chlorous acid must have to part with its
oxygen, and the chlorine thus left at liberty gradually con-
verts the lime, with which it is combined, into calcium.
And, were the powder kept long enough, it would doubt-
less be completely changed into chloride of calcium by
length of time. When such a change has taken place the
bleaching properties of the powder are, of course, at an
end. Many years ago, when I lived in London, I met with
specimens of bleaching powder on sale in some of the che-
mists shops very nearly effete. In these specimens almost
the whole combined lime had been converted into calcium,
and, of course, the salt into chloride of calcium.

In the preceding analysis I have not noticed a small quan-
tity of manganesic acid which bleaching powder always con-
tains. If you raise a solution of bleaching powder to the
boiling temperature, it assumes the beautiful red, or rather,
purple colour which characterizes solutions of manganesic
acid, and some of its salts. If the liquid be exposed to the
light of the sun it gradually loses its colour, while, at the
same time, a slight deposite of a black powder, obviously
oxide of manganese, takes place. The quantity of this acid
present in bleaching powder is small ; but, so far as my
observations extend, it is never absent.

Article IV.

An Easy Method of Filling Barometers. By a
Correspondent.

An accurate barometer is essential in gaseous investigations ;
but as boiling the mercury in the tube is rather hazardous,
and the fitting it on to an air-pump, a work of time and
attention; such an instrument is troublesome to make, or
expensive to purchase. Advantage may, however, be taken
of the vacuum produced in the barometer itself, and a cor-

1835.] 'Filling Barometers. s 441

rect instrument thus placed within the reach of every
practical chemist. The detail may be as follows :

Provide 1. A clean barometer tube, not less than -J inch
bore at the closed end, but which may run away to ^th at
the lower end, to save mercury, and not less than 33 inches
long.

2. A tube 8 or 9 inches long, -^ or f bore, open at both
ends, one end being drawn out to a fine aperture ; for pour-
ing in the mercury.

3. Four or five pounds of mercury, (8 or 10 lbs. would
be more convenient) which has been standing three or four
weeks under weak nitric acid, (1 acid to 10 water) ; or
distilled mercury if to be had.

4. An iron ladle, and a disc of sheet iron which will not
quite cover the mercury, when in the ladle.

5. A small wedgewood mortar, which the mercury will
i or I fill.

6. A turned wood box and lid, (such as are used for tooth
powder), not less than 1^^ inch internal diameter and depth;
which must have a hole through the lid large enough to
slide up and down the tube, and be varnished inside and
out, for the cistern.

The tube should be dried over a lamp or before a fire,
with the open end up, and covered with a bit of muslin to
keep out dust. In the mean while the mercury may be
placed in the ladle, with the iron disc floating upon it ; and
set on the fire till it boils, when it is to be instantly removed
and placed in the cold. Whilst it is cooling, a horse hair
must be passed quite down the tube to the closed end, or if
one is not long enough, two may be bound together with a
fibre of silk. A knot makes a difficulty in passing them
down. A fine silked thread, waxed to give it stiffness will
do, but the tube must then be cold first.*

As soon as the mercury is cold enough to handle, it is to
be poured into the wedgewood mortar, and the pouring
tube (2) having its point dipped below the surface to ex-
clude dust, is to be filled to about an inch by suction applied

• Wire does not answer, the tubes being very subject to snap after it, even
when silked.

442 An Easy Method of [Dec.

at the other end. This quantity will remain in, if the tuhe
is held at but slight declivity. The wide end being now
closed with the finger, the pouring tube is to be removed
to the barometer tube, which should be held mouth up, at
an inclination of about 45°. The point of the pouring tube
being entered into the mouth, the finger is to be withdrawn,
and the mercury poured in, by increasing the declivity of
the pouring tube. Thus the mercury runs down to the
closed end, and the air passed up by the horse hair, leaving
few or no bubbles. When it contains 3 inches of mercury,
however, it should be carefully examined all round, and if
any bubbles appear, they should be brought to the hair, by
gently tapping the tube, held almost horizontal with a bit
of wood, at the same time turning it slowly a little back-
ward and forward upon its axis, the hair being never
allowed to go below. This should be done at every 3 or 4
inches, to have a smooth column of mercury as the filling
proceeds. When the tube is thus full, the hair is to be
withdrawn, leaving an end of it in the vacancy left by its
removal, until that also is filled. The hair being now
withdrawn altogether, the tube is to be overfilled, so that
the mercury presents a convex face above the glass.

The open end is now to be stopped with a finger, just
moistened to give it closeness; which squeezing out the
superfluous mercury will effectually prevent all access of
air. The tube is now to be inserted in the mortar of quick-
silver, and brought to a vertical position, when a vacuum
will be produced by the descent of the mercury.

The lower end is now to be again tightly closed with the
finger, the tube lifted out of the mortar and brought gently
to a horizontal position. The finger must be kept tight
against the open end, to maintain the vacuum ; when a
minute portion of air will make a visible bubble in any part
of the column. By lowering the head a very little, the
mercury may be made to flow gently to that end, and leave
the vacuum next to the finger. By a short jerking motion
in the direction of its length, the tube and mercury are
kept in a sort of vibration, the mercury striking smartly
against the closed end, like the water hammer, and this
vibration brings together and carries upward toward the
finger, any bubbles which may be present in the column.

1835.]^ Filling Barometers. . 443

A very slight inclination is sufficient for this purpose, and
of course, any increase thereof tends to diminish the lowest
bubbles by compression : but a little change from less to
greater, and vice versa, puts in motion the stationary ones,
vehen there are such. If the tube is not clean, little
bubbles will fix themselves to any dusty part, and cannot
sometimes be moved unless by washing them away : pour-
ing the mercury gently from the head of the tube to the
finger, and back again three or four times.

When the mercury lies smooth for its whole length, the
finger is to be withdrawn, the hair put in and the 3 or 4
inches vacant carefully re-filled. The tube is then to be
stopped and inverted in the quicksilver with the same pre-
cautions as before, against the entry of a bubble under the
finger. When brought to the perpendicular position, it
should be turned round and examined on all sides, to see
that the column is perfectly smooth and bright ; and when
quickly inclined, so as to allow the mercury to reach the
head, it should return a smart rap. If both these conditions
are found, the tube is well filled ; but as a repetition of the
levelling and vibratory process for drawing off" the bubbles,
is a work but of little time and trouble, it is better per-
formed for the sake of security.

The tube thus twice purified from air, and replaced in the
mortar of quicksilver, wants only its cistern (6). The lid is
first to be plunged beneath the surface, and there slid up
over the tube, say three or four inches, where it is to be
fixed by a slight wedge, or slip of paper. The box is next
to be filled, plunged also under the quicksilver, and its
edge passed under the tube, which must rest in it, not quite
upright, so that it may be full to the head. The box and
tube, in this position, both full of mercury, are to be taken
out of the mortar and set on a saucer or plate ; when the
tube being brought upright, mercury will descend, and flow
over the sides of the box ; more is also to be withdrawn from
the box, by suction with the pouring tube, until about \ inch
deep is left above the bottom of the tube : a little more or
less, according to the state of the barometer, at the time,
above or below the average ; but if below, the average can
be attained by inclining the tube.

A slip of wood, say | inch square, but cut away at each

444 Gustav Rose, on Greenstone [Dec.

end to an edge, and exactly 29J inches long, must now be
placed in contact with the surface of mercury in the cistern,
and a mark made on the tube at its upper end : A scratch
is sometimes hazardous ; a little paint on a camels' hair
pencil is safer. The lid is now to be slipped down on the box,
and the whole removed from the plate, on to a piece of thin
chamois leather ; which being brought up over the box, is to
be tied tight round the tube ; and it may then be set on the case,
the box being supported beneath, to the proper height. If
the barometer stood at 29 J, or being below, was brought to
that height by inclination, the mark is a standard : if above,
it must be corrected for the depression of the surface in the
cistern. The scale must also be corrected, for the counter-
elevation and depression in the cistern ; which is conveni-
ently ascertained by previously filling 3 inches of the tube,
and measuring the height it occupies in the box with the
tube immersed ; allowance being made for its conical form,
if it be such. But this may be done by different methods,
generally known.

Such an instrument may be prepared by any practical
chemist, and may be trusted for common laboratory pur-
poses. For investigations of extreme delicacy, of course,
every possible precaution and perfection are required.

P.

Article V.

On the Rocks which are distinguished hy the names of Green-
stone and Greenstone Porphyry, By Gustav Rose.

( Concluded from p. 281. J

4. Gahhro a granular mixture of labradorite and diallage.
The labradorite is similar to that of the hypersthene rock,
still it is not so completely cleavable, and has more fre-
quently a thick splintery fracture, in which case the trans-
lucency is less, and the colour greenish-white or greenish-
gray.

The Diallage may be considered as an augite, which has
lost the faces of cleavage parallel to the front faces of a
rhomboidal prism of 88°. The first faces of cleavage are
very perfect, possess the metallic pearly lustre and streak ;
the edges run parallel with the second faces of cleavage ;

1835i] and Porphyritic Greenstone Rocks, 445

the last are much more imperfect and have a fatty lustre.
On account of the existence of the second faces of cleavage,
the diallage in the coarse granular varieties of gabbro
seldom splits in large pieces, but in plates, which are
not elastic, and are thus distinguishable from mica ; they
are frequently irregular and curved. Often the grains of
diallage exhibit a regular outline, and form symmetrical
hexagons with the same angles as in the most perfect faces
of cleavage of hypersthene. The colour is a dirty green
passing into gray, brown and black, often greenish and
grayish-white ; the complete faces of cleavage have a
metallic, pearly lustre, the others are faint, or have a fatty
lustre. The fusibility of diallage before the blow-pipe is
very small ; it melts on the platinum forceps in thin splinters
on the edges into a blackish-gray splendent glass.* The
fragments of diallage in Gabbro are more frequent and
more distinct than in the hypersthene of the hypersthene
rock, being surrounded with a deeper rind of hornblende.
This circumstance occurs in the diallage from Baste, in the
Hartz as described by Kohler. It is also observed, but
more characteristic, in the diallage of Gabbro, from the
village of Prese, between Bornio and Tirano in the Valte-
line. There the smaller portions consist wholly of horn-
blende, and the larger of diallage with a border of horn-
blende ; the latter is splendent and brown, and resembles
much the hypersthene in colour. It melts on charcoal
into a greenish-black bead.

Pinchbeck mica, iron pyrites, and titaniate of iron occur
as accidental constitu tents, but in small quantity ; frequently
serpentine occurs in some varieties. The cross fracture of
diallage has great similarity with that of serpentine.
Hence, we are apt to overlook the coarse mixture of the
former, which distinguishes it from the latter. Serpentine
has been considered by some as fine grained gabbro,-
but chemical analysis overturns this supposition. Gabbro
is very frequently coarsely granular. In this case the
labradorite predominates, but from the manner in which

• These characters are not the same as those given by Berzelius, in his work
on rhe Blow-pipe. Rose, therefore, supposes that ihe former has not examined
the right minerals, notwithstanding tli* observation, that the specimens were re-
ceived from Haiiy.

446 Gustav Rose on Greenstove [Dec.

the stone is fractured, the diallage appears to be present
in greatest quantity, although it is very thin.

In Ural a peculiar kind of gabbro occurs. A very large
grained variety is found at Neurode in Silesia, consisting
of grayish-white translucent labradorite, and olive-green
diallage, also at Baste in the Hartz, and near the Village of
Prese in the Valteline. A very fine variety exists in the
American collection of Humboldt, from Ayavaca in Peru,
consisting of much greenish-gray diallage, and some
greenish-white translucent labradorite ; gabbro mixed with
serpentine is found at Florence and Brian^on.

5. Augite porphyry consists of a basis with inclosed horn-
blende and crystals of augite. The basis has usually a dull
green and gray colour, like that of dioritic porphyry, but
is darker and more like basalt. Its hardness is about equal
to that of the basis of dioritic porphyry ; its fusibility is
smaller. It melts before the blow-pipe in the platinum
forceps, commonly on the edges into a blackish green glass;
muriatic acid when digested on it in a pulverized state
takes up alumina, oxide of iron, and much lime ; magnesia
and an alkali are probably also present.

The crystals of labradorite are much like felspar, being re-
gular six-sided prisms which usually by the extension of the
faces, (M) corresponding with the second faces of cleavage
become so broad, that in the mass, they appear from their
transverse fracture to be thin stripes. They are, however,
like the combined pieces, twin crystals ; and the most perfect
face of cleavage, (P) of the apparently single crystal pos-
sesses the resulting angle described ; still the faces of
cleavage are rare, and are only seen in the crystals as pure
and translucent as the albite of dioritic porphyry. The
crystals are mostly, scarce translucent, and the fracture
indistinct and splintery. The colour is partly snow-white,
and partly by mixture with the basis greenish and grayish-
white. Their size varies ; the largest. Rose found in the
augite porphyry of Ajatskaja, 130 versts (86 miles) to the
north of Katharinenburg in Ural, where their length, with
a considerable breadth, is more than an inch ; frequently,
however, they are small. In this case, they protrude very
little out of the basis which is then light coloured, and
scarcely darker than the crystals of labradorite. The large

1835.] and Porphyritic Greenstone Rocks. 447

crystals of labradorite from Ajatskaja, are more easily
detached from their basis than usually happens. Their
specific gravity, Rose found, 2*730. When reduced to
powder they were decomposed with great difiiculty by
muriatic acid. When fused with barytes, Rose found in
these crystals, as in the other specimens of labradorite,
silica, alumina, some portions of iron, lime, and soda.

The crystals of augite have the same form as when they
grow together ; they form four-sided vertical prisms of 88°,
with blunt and sharp lateral edges which have their extre-
mities terminated with an oblique four-sided prism of 120°.
They are cleavable in the direction of the faces of the
vertical prisms, and the truncatures of the lateral edges.

The faces of cleavage are more distinct than those of the
combined augite crystals in basalt, but more indistinct than
in the crystals of hornblende. They are on the upper sur-
face partly smooth and splendent, partly indistinct and
vertically, streaked faintly. In the first case they are
strongly, in the last case feebly united with the basis, from
whence they fall out when the rock is fractured, and leave
behind an impression, from which the form of the crystals
can be distinguished.

Their colour varies from grass-green to blackish-green ;
usually they are translucent. Before the blow-pipe small
fragments fuse on the edges with difficulty and frothing
into a green glass. In many instances, the crystals in the
combined augite porphyry have the form of augite, but
also two faces of cleavage which appear as sharp faces of
the sharp lateral edges of four-sided vertical prisms mea-
suring 88°, and cutting each other at an angle of 124° as
in hornblende. These are the crystals which Rose has
described under the name of uralite as occurring in UraL
He considers them as augite crystals, which retaining their
external form, have been converted into masses of horn-
blende. They possess a blackish-green colour ; the faces
of cleavage are faintly streaked vertically ; the surface of
the crystal is more strongly streaked and indistinct. Thin
fragments in the platinum forceps fuse before the blow-
pipe into a blackish-green glass, and more readily than
augite. They exist very distinctly in the augite porphyry
of Mostawaja, 35 versts to the north of Katharinenburg,

448 Gustav Rose on Greenstone [Dec.

and at the gold- washing station of Cavellinski near
Miask.

Frequently the crystals ofuralite have a nucleus of augite
possessing a grass-green colour, and whose cleavage faces
are parallel with the outer faces of the crystals of uralite.
The substitution of the mass of hornblende for the augite
is similar to the above described substitution of the horn-
blende masses for hypersthene and diallage. Hence, it is
probable that the hornblende which occurs in union with
this last substance, is also uralite. The union of augite and
uralite is found very distinct in the augite porphyry of Mul-
dakajeusk, near Miask, in Ural. But also other distinct
crystals of augite, as in the augite porphyry of Nicolajeusk,
are combined on the upper face with small prisms of horn-
blende, or if it be admitted, they have been changed into
the latter. Iron pyrites occurs interspersed through the
augite porphyry. Quartz, in crystals and grains, as well as
hornblende, with its peculiar form, and without combina-
tion with agite, appears, as in the hypersthene rock and
gabbro.

With regard to the proportion of the constituents, the
augite and labradorite of the augite porphyry are similar to
the albite and hornblende of the dioritic porphyry. Augite
porphyry occurs, which contains both constituents in nearly
equal quantity, but more frequently either the labradorite
or augite is present in the greater proportion. The crystals
in the augite porphyry lie generally irregularly ; in the
labradorite porphyry the crystals are arranged in a some-
what regular manner, having their broad lateral faces, or
at least, their main axes, parallel, (needle porphyry of South
Norway). The crystals appear needle-form, when the frac-
ture cuts the axes at right angles, and broad splintery, when
it goes parallel with the broad lateral faces of the crystals.

The principal masses of augite phorphyry are frequently
amygdaloid, when quartz is met with, never occurring both
in crystals and grains (Holmestrand, in South Norway, and
green labrador porphyry ; zeolite and calcspar also some-
times occur, (Tyrol) and Pistazite (Tyrol and Tscharysch in
Altai). Some varieties of augite porphyry occur, which it
is not easy to fracture, and it is usually difficult to obtain
from them portions of the size of a common book. Such

1 835.] and Porphyritic Greenstone Rocks. 449

examples occur at Muldakajewsk, near Miask, in Ural, wliich
contains crystals of Uralite with a nucleus of augite. There
are other varieties which assume a fine lustre and colour by
polishing. These are distinguished from ve^'de antique by
the large crystals of labradorite, which they contain, and
by the colour of the base. The following are the the spe-
cific gravities of some augite porphyries : —

Absolute
wt. in grs. Sp. gr.

1. Augite porphyry from Nicolajewsk,

near Miask, in Ural 464'47 - 3*002

2. Uralite porphyry from Maldaka-

jewsk, near Miask 681*23 - 3*100

3. Uralite porphyry, from Cavellinski,

near Miask 416*88 - 3*030

4. Uralite porphyry, from Mostowaja,

near Katharinenburg, in Ural . 369*54 - 2*993

5. Labrador porphyry, resembling ver-

de antique . : 373*06 - 2*923

6. Labrador porphyry, from Tscharisch 331*76 - 2*878
From this it is obvious that the Labrador porphyry pos-
sesses a less density than augite porphyry, which is to be
expected, considering that labradorite is lighter than augite.

Crystals of uralite were taken out of the basis of the au-
gite porphyry of Mustowaja, and the crystals and basis
weighed separately.

The sp. gr. of the uralite was found to be 3*150; that of
the basis, 2*991. This result is, however, not quite satis-
factory, as it was not possible to separate the crystals com-
pletely from the basis, and the base, when broken in small
portions, still contained uralite.

The augite porphyry of Muldakajewsk melts in a platinum
crucible, in a strong heat, into a blackish-green translucent
glass. In a charcoal crucible, the augite porphyry of Mota-
waja, Cavellinski, and Nicolajewsk, fuses into an opaque
mass of a yellowish-white, or grayish colour. At the lower
part iron is collected, containing copper- red titanium. In
fusing verde antique a similar deposit is observed, with tita-
nium inclosed.

Augite porphyry is found among all the rocks which are
usually termed greenstone ; but, in particular it occurs in

VOL. II. 2 G

468 Gustav Rose, on Greenstone [Dec.

great abundance in Ural. The presence of oxide of iron,
which accompanies it in this locality, communicates a pecu-
liar interest to it. Some large magnetic mountains, as
Blagodat, near Kuschwa, Wisckaja Gora near Nischne
Tagilsk, Katschkanar near Nischne Turinsk, are surrounded
by augite porphyry, and appear to pass through this rock.
The greater part of these porphyries is augite or uralite.
Those containing labradorite are more rare in Ural. The
last are encountered, however, at the village of Ajatskaja,
to the north of Katharinenburg ; the basis is grayish or
yellowish ; the size of the labradorite varies.

Other beautiful varieties come from Altai, and particu-
larly from the river Tscharysch. They surpass those of
Ural in beauty, possessing white labradorite and blueish-
green augite, with a variegated basis. Among the most
remarkable labradorite porphyries of other countries the
verde antique may be noticed. The basis is beautiful
green ; the crystals of labradorite are very large, but always
coloured greenish- white. Iron pyrites, pistagite, and quartz
occur in it.

The finest varieties in Germany are found in the Hartz,
as between Elbingerode and Rubeland, between Blanken-
burg and Huttenrode. The Miihlthal, between RUbeland
and Elbingerode, contains also a number of rolled frag-
ments of this porphyry. The basis is blackish-green, and
sometimes reddish-brown, produced by incipient decomposi-
tion. The crystals are white, or greenish-white. Small
round pieces of carbonate of lime are found disseminated
through the basis.

Porphyry containing equal parts of labradorite and augite
occurs at Blagodat, near Kuschwa, in Ural, and near Dil-
lenburg (Nassau). There the basis is blackish-gray; the
crystals of labradorite grayish white, and scarcely translu-
cent; the crystals of augite are blackish-green, with a con-
choidal fracture. The acicular porphyry of South Norway
belongs to this variety ; it has been described by Von
Buch« Porphyry, containing augite as its principal ele-
ment, is met with at Nicolajewsk, near Miask, and Nischne
Tagilsk.

There the augite is large, and grass-green ; the crystals are
easily removed from the basis, and leave their impression.

1835.] and Porphyritic Greenstone RocJiS. 4S1

The augite porphyry of Tisenz, in Tyrol, resembles closely
that of Nicolajewsk. Those of Steben, in the Fichtelgebirge,
and Holmestrand (South Norway), have a deeper basis ;
the crystals in the Fichtelgebirge are of a pistachio green
colour, and small in number; in Holmestrand they are
greenish-black, very abundant, and give to the mass the
appearance of basalt. The uralite porphyry is more abun-
dant than the augite porphyry. Among the most remark-
able varieties are those at Cavellinski and Mostowaja.
The basis of the first is greenish-gray, and hard, without
labradorite. The crystals of uralite are abundant, and
firmly fixed. lorn pyrites occurs in it. The basis of the
second is more clear ; the uralite is less firmly fixed. La-
bradorite may be observed, but not until the rock is pounded.
This porphyry resembles that of Lake Baltyn, which Her-
mann has termed Baltynite. The uralite porphyry appears to
be more rare in other chains of mountains ; but it occurs in
Tyrol; in Mysore (India), at Newstadt; the basis is blackish-
green ; the crystals of uralite are small, but distinct.

Such are the great divisions into which the greenstones
may be separated. They are mostly found in primitive or
transition slates, and particularly in talc slate, chlorite slate,
and clay slate, as in the Uralian mountains, or in clay slate
and greywacke, as in the Hartz, and Fichtelgebirge. They
resemble some of the primitive rocks. Thus, diorite is an-
alogous to syenite ; but syenite is a mixture of grains of fel-
spar and amphibole, generally black, or albite is seldom
found. It is further distinguished from diorite, by being
generally found with granite, or red porphyry.

Hypersthene rock resembles dolerite, which is a mixture
of grains of labradorite and black augite, and accompanies
basalt. Augite porphyry approaches basalt. Amphibole is,
however, rare in basalt ; olivine never occurs in augite por-
phyry ; the basis of basalt is deeper coloured, and contains
augite equally black, and, besides, olivine and amphibole ;
the colour of the augite basis is often very deep in many
augite porphyries, and reciprocally, many true basalts are
met with containing olivine and augite of a fine green
colour. Recent lavas closely resemble augite porphyry,
such as those of Vesuvius, which contain green augite, and

2g2

452 On Madder, and [Dec.

those of Etna, possessing augite, and labradorite. Whether
these are all true species, future researches must determine.

Article VI.

On Madder, and Madder Dyeing.*

Species of Madder . — The species of madder mentioned in
this paper are : 1. Spires' madder, sold at 28 rixdollars the
hundred-weight (centner) ; 2. Munjeet, at 28 rixdollars ;
3. Avignon madder, 27J rixdollars ; 4. Secondary quality,
from the same place, 20 rixdollars ; 5. Alsace madder, 25
rixdollars; 6. Dutch madder, 25 rixdollars ; 7. Alizari, or
Levant madder-root, 22 rixdollars; 8. Autumn-red (^erJs^-
rothe) 18 rixdollars; 9. Red bud {Keimrothe) 12 rixdollars.
All these varieties absorb different quantities of moisture
when exposed to the air ; so that it is necessary to dry them
at the temperature of 212° F. before weighing them.

Cotton Mordants. — For testing and examining Aiadder
chemically, the aluminous cotton mordant {Thonhexz-kattun)
is of great importance. The process consists in impregnat-
ing the cloth with acetate of alumina ; by immersing it in
a solution consisting of 30 parts of alum, 30 parts acetate of
lead, and 80 parts of water, pressing it between cylinders,
and drying it rapidly. It is then allowed to hang up for
eight days, washed in a stream of water, afterwards boiled,
and lastly, for the purpose of experiment, passed through
distilled w^ater.

The iron mordant for cotton, mentioned in this paper, is
formed by impregnating the cloth with a solution of iron
and alum (1 in 120 water) and washing it. A black mor-
dant enables the qualities of the colouring matter to be
more readily distinguished. This mode of proceeding is
analogous to the re-action, ascertained by testing dilute
solutions.

• Tins paper constitutes an excellent sequel to those which were published in
the first volume of this Journal ; as its object is to present a more minute descrip-
tion of the formation of several of the colours attached to these papers. It is taken
{rova. Erdmann und Schweigger SeideVs Journal, far Praklische Ckemie, v. 362;
into which periodical it has been extracted, from the " Chernische technische
Monographic des Krapps oder vergleichende untersuchunguti der Krappfarbestoff
und der verschiedenen Krappsorten : Alizari, Krapp, Munjeet und Rothe in ihrem
verhalten xur geheizlen Baumicollenfasser , von Dr. F. Y. Runge."

1835.] Madder DyeAn^. 46^

Tin mordant is formed in the same way as the iron mor-
dant, by means of a solution of 1 part salt of tin in 50 parts
of pure water.

Lead mordant, with a solution of sugar of lead, 1 part
sugar of lead in 30 parts of water. The cloth should be
rinsed after impregnation. It takes up, in these circum-
stances, a sufficient quantity of oxide of lead.

Copper mordant is formed by a similar proceeding with
ammoniuret of copper. By dipping and washing the cloth
in this solution, the cotton fibre absorbs as much oxide of
copper as is sufficient to produce the requisite dark colour.

Testing the Colour. The cotton which has received the
mordant may be submitted, in the hands of the chemist, to
a double test, so that its qualities may be determined both
qualitatively and quantitatively. The peculiar shades which
the colouring matter produces, in combination with the
cotton, may be termed the goodness, and the degree, or
the depth of shade, the value of the colour. By proper
treatment, both of these properties, as well as the peculia-
rities of the cloth, may be determined by one process.

A small quantity of the colouring matter is weighed out,
and heated with pure water, in a porcelain dish, over a
sprit-of-wine flame ; equal portions of the cotton, impreg-
nated with the mordants, are placed in it, and coloured in
succession, the solution being gradually raised to the boiling
point. When the first portion of cotton appears to absorb
no more colour, it should be removed, rinsed in a little
water, and its absorption again urged. The same trials are
to be made with the second, third, and fourth portions,
until that point is attained where the absorption of colour-
ing matter terminates, and where, consequently, the cotton
receives no additional colour.

After being dried, the pieces of cotton which have been
equally saturated, are to be weighed, and the power of the
cloth to receive colour ascertained. In this way, I have
ascertained the saturating power of the three madder pig-
ments treated of in the subsequent part of this paper. When
a colouring substance contains a mixture of several colour-
ing matters, by this successive dyeing, a partial separation
can be produced. We obtain, at the beginning and end of
the process, quite different shades, (Runges Farhenchemie,
174 J. As in this case, and in many others, the first portions

454 On Madder, and [Dec.

of cotton dyed, are equally, as it were, supersaturated with
colouring matter, and possess a shade whiqh the dyer does
not intend, as is the case with the saturated combination
of madder purple with the alum mordant ; it is necessary to
determine the proportions in which the colouring matter
must be added to the cotton, in order to produce a definite
shade. This is done (after the proportion is determined in
which the cloth can take up the greatest quantity of colour-
ing matter) by using the same weight of colouring matter,
but different weights of cotton, perhaps the double, triple,
or quadruple quantity, making many trials of the colouring
power, and placing the pieces, not successively, but at once,
in the solution. By this method of proceeding I have ar-
rived at the result that 1 part of madder-purple, with 80 of
cotton, produces a saturated red.

To determine, chemically, the difference of one colouring
matter from another, it is necessary to apply an excess of the
colouring matter to the cloth. In this way I have found that
madder-red is most completely distinguished from madder-
purple. (Rungeuses for these purposes a dyeing apparatus
consisting of a steam and dye boiler, with a worm and
refrigatory. The temperature reaches from 207°J to 209°-|).

Constituents of Madder. — The root of madder, in reference
to its chemical composition, is very remarkable. It con-
tains seven different substances, six of which are peculiar
coloured compounds, and three of the latter true dyes. By
the following process these may be distinguished from each
other. Their names are derived from their properties : —

1 . Madder-purple ^ is an orange-coloured crystalline pow-
der. It imparts to the cotton which has received the mor-
dant a deep reddish-brown purple colour, when it is em-
ployed in excess. If, on the contrary, the cotton is in
excess, the colour is a bright red. A boiling solution of
alum forms with the madder-purple a cherry-red solution,
which is not altered on cooling, if not in excess. Caustic
potash forms with it a fine cherry-red colour. Solution of
carbonate of soda forms a cherry-red solution, which is not
altered by potash. Sulphuric acid produces a bright red
colour.

2. Madder-red^: is a yellowish-brown crystalline powder.

* Records of General Science, vol. i. p. 15. t Ibid. 14.

1835.] Madder Dyeing. 466

It imparts to the cotton which has received the mordant a
dark-red colour, when in excess ; but when the cotton is in
excess a brick-red colour is produced. Boiling solution of
alum does not dissolve the madder-red. When this happens
it proceeds from madder-purple or madder-orange being
mixed with it. Caustic potash forms a fine violet-purple
solution. Solution of carbonate of soda forms a red liquid
which becomes blue by the addition of potash. Sulphuric
acid forms a brick-red solution.

3. Madder-orange^ a yellow crystalline powder. It im-
parts to the mordanted cotton a bright orange colour when
in excess, but paler when the cotton is in excess. Boiling
solution of alum forms with the madder-orange an orange-
yellow solution, which, on cooling, deposits a little colour-
ing matter. Caustic potash produces a dark rose-colour.
Solution of carbonate of soda affords an orange-coloured
liquid. Sulphuric acid produces an orange-yellow colour.

4. Madder-yellota, a yellow gummy mass ; communicates
to the mordanted cotton a pale nankin colour, and is not a
true dye.

5. Madder-brown, a brownish-black dry mass ; communi-
cates no colour to cotton ; neither is it soluble in water nor
in spirit-of-wine.

6. Madderic acid (Krapfsaure) is a colourless acid.

7. Ruhiacic acid is also a colourless acid ; by heating with
muriatic acid, it is converted into a matter which forms a
clear blue colour, but cannot be fixed upon cotton.

The three first of these alone deserve an attentive con-
sideration, in so far as manufacturers are concerned.
i Madder purple. — The separation of madder purple in a
state of purity is attended with considerable difficulty. It
is effected by the following operations : 1 . Washing the
madder with water of the temperature bQ^^ to 70° F. 2.
Boiling the washed madder with a strong solution of alum.
3. Precipitating the madder purple from the alum solution
by means of sulphuric acid. 4. Edulcorating and boiling
the precipitated madder purple with water, and then with
dilute muriatic acid. 5. Taking up the boiled madder
purple with spirit of wine of 90°. 6. Evaporating the spirit
of wine solution to the point of crystallization. 7. Dissolv-
ing again the crystallized madder purple in hot spirit of
wine, and re-crystallizing. The madder purple obtained

456 On Madder, and [Dec

in this way is a light crystalline powder, of a beautiful
orange yellow colour.

The operation of washing ground madder is important,
and accompanied with loss. The Levant madder is easily
washed, and should, therefore, be employed for the separa-
tion of madder purple. It contains, however, of all the
varieties, the greatest quantity of colourless matter soluble
in w^ater, and must, therefore, be macerated and washed
with fresh w^ater six times for 12 hours, when cut up into
considerable pieces. In order to save time and water, six
vessels may be made use of, which communicate with each
other. Each of them is to be filled half full of Levant
madder (Alizari); the first vessel is to be filled up with water.
After 12 hours, the water should be drawn off" and digested
on the madder in vessel No. 2. Then the first vessel
should be again filled up with fresh water. After the lapse
of 12 hours, the water in No. 2 is to be transferred to the
vessel No. 3, while that in the first takes its place, and the
first is again filled up with fresh water. This operation is
repeated until fresh water has been introduced six times
into the first vessel. The madder of this vessel is now suffi-
ciently washed, and is fitted for the separation of the mad-
der purple. 4 lbs. of Alizari in large pieces, after being
w^ashed six times, weigh in the moist state 15J lbs. It is
then very soft and is readily reduced to pulp. To separate
the madder purple from the washed Alizari, take \6\ lbs.
of moist Alizari, 12 lbs. alum and 70 lbs. water, boil for an
hour, and filter the red solution, which is a combination of
madder purple with solution of alum. Then the residual
root is boiled with 6 lbs. alum and 70 lbs. water for half
an hour, the filtered solution mixed with the portion of
fluid formerly, withdrawn, and allowed to remain at rest for
four hours, in order to clarify. The boiled roots should
again be boiled with 70 lbs. of water, and the solution em-
ployed for digestion with fresh madder. When the alum
solution containing the madder-purple has become com-
pletely clear, and acquired a dark rose colour, it should be
drawn olF from the sediment, which is principally madder-
red, mixed, and well stirred, with a solution of 8 lbs. sul-
phuric acid and 9 lbs. water. In the course of a few days
the liquid becomes of a yellow colour, and reddish-yellow
flocks separate. These should be collected on a filter and

1835.] Madder Dyeing. 457

edulcorated with pure water. When dried, this precipitate
amounts to ^ of an ounce, (IJ loth) and consists of impure
madder-purple containing madder-yellow, madder orange,
and alumina ; it is somewhat soluble in hot water ; more
soluble in spirit.

In order to separate the madder-purple from all foreign
matter, the precipitate should be boiled with much water,
and then with dilute muriatic acid, several times, then edul-
corated, dried, and boiled with spirit of 85 to 90, and fil-
tered while hot. A dark-red solution is thus obtained,
which, after evaporation, deposits, on cooling, the madder-
purple in the form of an orange-coloured crystalline sub-
stance. This is separated by the filter, and is further iso-
lated from the mother liquor by solution in spirit, and a
second crystallization. Lastly, it should be dissolved in
ether, which leaves a brown matter.

These operations, as may be readily observed, are not
intended to be practised by the manufacturer, but they must
be attended to in order to obtain the colouring matter in
its purest state.

The great quantity of alum required for the separation
of the madder-purple from the madder-root, may be again
obtained by evaporating, in lead vessels, the alum solution
mixed with sulphuric acid, out of which the madder-purple
is precipitated and separated, when the alum separates in
crystals. The mother liquor then consists of a solution of
alum and sulphuric acid, which will answer again for the
precipitation of the madder-purple ; and the alum by cry-
stallization, freed from sulphuric acid, may be again em-
ployed to take up the madder-purple. By this process the
madder-purple is refined.

( To he continued.)

Article VII.

An account of the process of making Spirits, in
Great Britain and Ireland.^

In giving an account of the processes followed by the dis-
tiller in making spirits, it may be necessary to enumerate
the vessels and utensils employed in these processes : These
are, the mill, mash-tun, coppers, under-backs, coolers,

* I am indebted for this article to a gentleman of great experience in the
manufacture of Spirits. — Edit.

458 On the Process of making Spirits^ in [Dec.

wash backs, fermenting tuns, charging backs, stills, low
wines receivers, low wines chargers, feints receivers, and
spirit receivers.

Of these vessels no distiller can, under the Excise regu-
lations, have more than one wash charger, and one spirit
receiver ; nor more than two low wines, or feints receivers,
and two low wine and feints chargers ; but the number of
his other vessels is not limited.

1. A mill for grinding the malt and grain. — In England
and Ireland, where little or no spirits are made entirely
from malt, the grain is ground with stones : but in Scot-
land, where malt spirits are chiefly made, the malt, though
sometimes ground with stones, is often bruised between two
metal rollers, and in some instances, where the works are
not extensive, another kind of mill is employed, somewhat
resembling a coffee-mill, both in appearances and construc-
tion, and called a hand-mill, from its being turned by one
or more men. The powers employed to drive the other
kinds of mills, are water, steam, or horses, according to
circumstances.

2. The Coppers. — These are large boilers, usually made
of copper, from which circumstance they derive their
names. Their use is to heat the water, &c., employed in
the process of mashing, as hereafter to be described.

3. The Mash-tun is a large and generally a circular vessel,
made of wood or cast iron. It is usually furnished with a
plate called a *' false bottom," which is perforated with a
great number of small holes, and lies within an inch or two
of the real bottom. This plate, which is moveable, to faci-
litate the clearing of the mash-tun, is laid down in its place
previous to the commencement of each brewing ; and the
ground malt or grain to be operated upon (technically
called grist) is then put into the tun, after which water is
let in under the false bottom, at a temperature about 175°,
(but the temperature varies with circumstances, malt re-
quiring hotter liquid than mixed grain), and the whole
stirred up, either by means of machinery, or with oars
weilded by workmen, until the mash, as it is called, has
been thoroughly mixed ; the whole is then covered up, and
allowed to remain for some time, till the water has absorbed
as much of the saccharine matter from the grain as possible,
when, by means of cocks fixed in the mash- tun, the liquor

1835.] Great Britain and Ireland. 459

is drawn off into the under-back, which is a vessel adjusted
for thus receiving the wort. More hot water is added, and
the mashing process repeated, until the grain has been
wholly deprived of its saccharine matter, which is generally
accomplished by three, or at the most, four mashings, when
nothing remains in the mash-tun but the husks, or dratf,
which are used as food for cattle.

4. The Under-hack is a vessel placed under the mash-tun;
its use is simply to receive the liquor from the mash-tun,
which has become sweet tasted, and is then called worts,
possessing a specific gravity exceeding that of water, varying
according to the quantity of saccharine matter it holds in
solution ; all these worts are in rotation pumped up from
the under-back, and the first, or sometimes first and second
worts, that is, the worts obtained from the first and second
mashings are pumped into the coolers, from whence, when
sufficiently reduced in temperature, they are conveyed into
the fermenting tun. The subsequent, or weaker worts,
produced by the third or fourth mashings, are pumped into
the coppers, where, being brought to the proper tempera-
ture they are used as liquor in the succeeding operation.
Sometimes, instead of being so used, they are boiled down,
till, by evaporating a portion of the water, the remainder
has been raised to the required strength, or specific gravity
which fits it for being sent to the fermenting tuns. The
gravity is ascertained by means of an instrument called a
saccharometer.

The first accurate instrument of this kind was invented
by Dr. Thomson of Glasgow, about thirty years ago, and
constructed by Mr. Allan, of Edinburgh, whose name it
bears. It consists of a brass, egg-shaped ball, poised un-
derneath, with a stem rising above, which is furnished
with a line of numbers, indicating the specific gravity of
the sample under examination, at the temperature of 60°;
a scale of difference accompanies it, for making corrections,
according as the temperature varies, either under or over
60°. Its application for revenue purposes in Scotland has
been legalized by several acts of Parliament. The saccha-
rometer used for revenue purposes in England, is known
by the maker's name. Bate. It differs from Allan's, in hav-
ing its weights, or poises, under the liquor ; the weights

460 On the Process of making Spirits in [Dec.

of Allan's being applied above the liquor ; but both instru-
ments indicate specific gravity, — that is to say, the weight
of a given bulk of the worts, supposing the same bulk of
distilled water to weigh 1000.

The strength or value of worts is estimated according to
their specific gravity, which, on reference to tables con-
structed for the purpose, shews the quantity of saccharine
matter, or solid extract contained in a gallon of any given
degree of specific gravity.

The following is a specimen, extracted from Bate's Sac-
charometer Tables : —

Sp. gr. lbs. per gal.

1-030 -752

1-035 -904

1-040 1-033

1-045 ...... 1-163

1-050 1-293

1-055 1-422

1-060 1-552

1-065 1-682

1-070 1-882

1-075 ...... 1-941

1-080 2-071

1-085 2-201

1-090 2-332

The saccharometer is of vast importance to the practical
distiller, and its invention forms an era in his art, for, by it
he is enabled to estimate, with considerable precision, the
quantity of spirits to be expected from worts of any gravity,
as will be shewn hereafter ; by it he also estimates the
value of the grain employed, and, of course, the quantity
of worts at any required specific gravity to be obtained
from any given quantity of grain employed. For example,
supposing, (which is near the truth, where large proportions
of oats are used), that one hundred-weight of mixed grain
will yield 70 lbs. of saccharine matter in the mash-tun,
and that such grain weighs 42 lbs. per bushel, then, as
112 : 70 :: 42 : 26-2, the saccharine matter which each
bushel will produce. Now, if it is wished to be known how
many gallons of worts at any given specific gravity will be
obtained from a bushel of such grain, we have only to divide

1835.] Gnat Britain and Ireland, 461

26*2 as above, found by the pounds per gallon shewn in the
above table, and the quotient will shew the number of gal-
lons to be obtained.

These quantities, however, are not to be taken as abso-
lute, inasmuch as the quality of the grain, and the skill of
the mash-man are not equal in every case, but in practice,
they will be found to approximate very near the truth.

5. Coolers. — There are various kinds of coolers, and their
object is simply to reduce the temperature of the worts as
speedily as possible, to a temperature, at which yeast can
safely be added for inducing fermentation. If worts are
not cooled rapidly, they are apt to run into acidity, which
diminishes their susceptibility of the vinous fermentation,
and consequent developement of the spirits therein. The
coolers in general use, are large oblong shallow vessels,
and the worts are laid on them to the depth of from one to
three or four inches only, a large surface is thus exposed
to the atmosphere which absorbs their heat, and soon
brings them to the temperature required.

Besides the shallow coolers which we have just described,
and which are the utensils most generally used by distillers
for cooling their worts, various contrivances have been
resorted to for accomplishing this object, by means of
pipes, through which the hot worts are made to pass, while
a current of cold water flows along their external surface,
and sometimes the reverse is practised, viz., the cold water
is made to pass through the pipes, the hot wort being
applied to their external surface. We have lately seen in
Scotland, a very compact form of cooling pipes, the object
of which is, not merely to cool the wort with rapidity, but
also to economize fuel, by saving the heat abstracted from
the worts, and applying it to the subsequent processes.
This apparatus consists of a great number of small pipes,
about one inch diameter and six or seven feet long, standing
perpendicularly beside each other and very close. The
lower end of each pipe is inserted into the top of a shallow
close chamber, and the upper end into the bottom of a
shallow open vessel ; each pipe being thus open and ac-
cessible, so as to be cleaned when necessary, even while
the process of cooling is going on. There is a cock in the
close chamber below, for carrying off the cooled worts, and

462 On the Process of making Spirits in [Dec.

the whole apparatus is immersed in a cistern of water, just
large enough to hold it. The hot wort is allowed to flow
into the pipes hy the open vessel at top, while an equal
quantity of water enters the cistern at bottom, and flows
off at top to the coppers, carrying with it all the heat ab-
stracted from the worts. Supposing the worts to be thus
cooled down from 150° to 70°, the water will by this pro-
cess acquire 80° of heat, and will reach the coppers at a
temperature of 120° or 130°, instead of 40° or 50°. This
arrangement of cooling pipes which seems well adapted to
its intention, is the invention of Mr. Coffey, a distiller of
Dublin, who is also the patentee of a distilling apparatus,
of which we shall have occasion to speak hereafter.

6. Wash-hacks, or fermenting tuns. — After the worts have
been cooled down to the proper temperature, which is
determined by their strength, the season of the year, or
rather by the temperature of the weather, and the bulk of
worts to be collected and fermented in one vessel, they are
collected into vessels called wash-backs, or fermenting
backs.

These vessels are sometimes made" in the form of a cone,
standing on its larger base, and either round or oval, some-
times they are square ; some are constructed of wood, and
others are made of iron ; each material has its advantages
and its disadvantages, iron being a better conductor of
heat, has this advantage that either hot or cold water may
be applied in an outside case, to regulate the temperature
of the wash contained in the back, which is a point much
to be attended to by the distiller, for if the temperature
get too high, which it is apt to do, fermentation is checked,
after which, it can with difficulty be again induced ; and if
the temperature get too low, somewhat similar effects are
produced, until means are taken to raise the temperature.
Fermentation is one of the most important, as well as the
most difficult processes to regulate, of all the distiller's
operations, and requires much of his skill and attention to
conduct it to a proper termination.

It was formerly the practice to add brewer's yeast only
to the worts, for the purpose of inducing fermentation, but
the expense of that article, and the difficulty of obtaining
it fresh and good, in remote situations, has lately induced

1835.] Great Britain and Ireland, 463

distillers to employ a substitute, which is technically called
bub, and is prepared thus : a quantity of warm worts and
water is put into a vessel, with a quantity of meal or
flour, together with some yeast, the whole is well mixed
together and closely covered up ; a violent fermentation
almost immediately ensues, and in that state it is added to
the worts in the wash-backs, and excites the whole mass
to ferment; but should the fermentation, after some time,
be found to lag, some yeast is added, but for revenue
purposes, the whole quantity of bub and yeast added, is
restricted to the proportion of not more than five per cent,
on the quantity of worts previously collected ; in general,
however, that allowance is found more than sufficient.
Soon after yeast or bub has been added to the worts, fer-
mentation commences ; its first efi'ects are indicated round
the sides of the back, by the appearance of a scummy
looking matter on the surface of the worts, and the emis-
sion of small bubbles, which contain carbonic acid gas ;
the temperature increases as fermentation advances, its
progress is rather slow at first, but gradually increases,
and after some time proceeds with prodigious rapidity;
large bubbles of carbonic acid gas escaping set the whole
in motion, as if in a state of violent ebullition ; a large
quantity of froth collects on the surface of the liquor,
(which is now called wash) which often accumulates with
such rapidity, that several men are required to beat it down
with oars to prevent its spilling over the top ; indeed, on
some occasions, the beating on the top has been found in-
effectual, and the distiller forced to pump a portion of the
wash up to the coolers to lower its temperature, and then
return it, after which the process j^roceeded at a moderate
rate ; and, in all cases towards its close, the rate of fermen-
tation gradually diminishes and the temperature decreases,
till at last the wash acquires the temperature of the tun
room and remains quiescent.

The object of the distiller is to carry fermentation to the
greatest possible extent, because his produce in spirits w411
be according thereto; and, indeed, the extent of the at-
tenuated gravity (that is, the difference of the specific gra-
vities before and after fermentation) is a pretty exact, per-
haps an absolute measure of the proportion of spirits con-
tained in the wash ; it is therefore adopted by the revenue

464 On the Process of making Spirits in [Dec.

as a prescriptive charge upon the distiller. But the mat-
ter will appear more obvious, by giving' a brief explanation
of the principles on which the theory is founded : viz., that
by the saccharometer can be inferred the quantity of sac-
charine matter contained in worts of any specific gravity,
and that every pound weight of such matter decomposed by
fermentation, produces -905 parts of a pound of proof spirits
at the specific gravity of 920, water being 1000 at the tem-
perature of 60.

To give an example, suppose 100 gallons of worts were
made at the specific gravity of 1*060, and attenuated by fer-
mentation of the sp. gr. of 1*001. Here, however, it may
be necessary to notice, that the one degree, which is called
the lowest attenuated gravity, is not the real gravity of the
wash were it deprived of the spirits contained therein, it
must first be boiled till all the spirits are dissipated, and
pure water added to make up the original bulk, and it will
then be found, that instead of 1*001, the specific gravity
will have become 1*011, (the difference which is 10, is due
to the operation of the spirits in the wash before boiling).

Having thus explained, we find from the tables before
adverted to, that 100 gallons worts at the gravity of 1*060
contain,

155*2 lbs. saccharine.
100 gals. 1*011 = 28*4

126*8
*905

6340
114120

920) 114*7540 ( 12*47 gallons proof.
920

2275
1840

4354
3680

6740
6440

300

1835.] Great Britain and Ireland. 465

Thus, we see that 114*75 lbs. saccharine matter had been
decomposed, and -965 parts of an equal weight of proof
spirits formed in its stead, and as a gallon of proof spirits
weighs 9*20 lbs., we find that 1247 gallons of such spirits
would have been formed, being at the rate of one gallon of
such spirits in respect to every 100 gallons of wash, for
every 4*7 degrees of attenuated gravity nearly.
(To he continued.)

Article VIII.
Analyses of Books.
I. — Philosophical Transactions of the Boyal Society of
London, for 1835. Part i.

( Concluded from p. 390.^

Physics.
Note on the Electrical Relations of certain Metals and Metalliferous
Minerals. By R. W. Fox. The author states that the crystallized
gray oxide of manganese holds the highest place in the electro-
negative scale of any substance examined, when it is immersed in
various acid and alkaline solutions ; and the other metals and minerals
rank after it in the following order : manganese, rhodium, loadstone,
platinum, arsenical pyrites, plumbago, iron pyrites, arsenical cobalt,
copper pyrites, purple copper, galena, standard-^old, vitreous copper,
silver, copper, pan brass, sheet iron. When employed in voltaic
combination he found that on being so arranged as to act in opposition
to one another, the direction of the resultant of their action, as indi-
cated by the deflection of the magnetic needle, did not coincide with
the mean of the direction of the needle when under the separate in-
fluence of each. He concludes, therefore, that the needle does not
indicate the whole of the electricity transmitted, and that electro-
magnetic action does not depend upon a continuous electric current,
but is better explained on the hypothesis of pulsations, formerly
advanced by him.

Experimental Researches on Electricity, Ninth Series. By
Michael Faraday, D.C.L. &c. '

The inquiry which produced the developement of the facts con-
tained in this paper arose from the observation of Mr. Jenkin, that,
if an ordinary short wire be employed to form a communication be-
tween the two plates of an electrometer consisting of a single pair of
metals, it is impossible to procure an electric shock, but if the wire
which surrounds an electro-magnet be used, a shock is experienced
whenever the contact with the electrometer ceases, if the extremities
of the wires are held in the hand, while a briUiant spark appears at
the point of disjunction. In the prosecution of his researches the
author employed the conducting wire in four different modified forms :
1 St, as the helix of an electro- magnet, consisting of a cylindrical bar
of soft iron, 25 inches long and 1 J inch in diameter, bent into a ring,

VOL. n. 2 H

4^ Analyses of BooJis. [Dec.

which was soldered to a copper rod which served as a conducting
continuation of the wire : 2nd, as an ordinary helix formed of a
copper wire coiled round a pasteboard tube, the convolutions being
separated by a string, and the superposed helices prevented from touch-
ing by intervening calico : 3rd, as a long extended wire, and 4th, as a
short wire. Of all these forms, the brightest spark and most powerful
shock are procured by inserting a cylinder of soft iron within the helix,
so as to form an electro-magnet. He found, also, that if a current
be established in a wire, and another wire forming a complete current
be placed parallel to the first, at the moment the current in the first
is stopped, it induces a current in the same direction in the second,
the first exhibiting then but a feeble spark ; but, if the second wire
be removed, a current is induced in the first wire in the same direction,
and a spark elicited when the contact is broken. The strong spark
in the single long wire or helix, is therefore, the equivalent of the
current which is induced in a second wire placed parallel and in
connexion with the first wire. From the facility of transference to
neighbouring wires, and from effects generally, he considers the
inductive forces to be lateral, i. e. excited in a direction perpendicular
to the direction of the originating and produced current, and they
also appear to be accurately represented by the magnetic curves, and
closely related to, if not identical with magnetic forces. All experi-
ments tend to shew that the elements of the currents do not act upon
themselves, but excite currents in conducting matter which is lateral
to them. On using a voltaic battery with fifty pairs of plates the
effects were exactly similar to those with a single pair. The author
concludes with remarking upon the advantages presented by electro-
magnetic machines, in which the current is permitted to move in a
complete metallic circuit of great length during the first instant of its
formation, by which means great intensity is given by induction to
the electricity which at that moment passes.

On the Determination of the Terms in the Disturbing Function,
of the Fourth Order, as regards the Eccentricities and Inclinations
which give rise to Secular Inequalities. By J. W. Lubbock.

In the theory of the secular inequalities, the terms in the disturbing
function of the fourth order, as regards the inclinations, have hitherto
been neglected. As the magnitude of these terms depends, in a great
measure, upon certain numerical co-efficients, it is impossible to form
any precise notion, a priori, with respect to their amount, and as to
the error which may arise from neglecting them. The author has,
therefore, considered it desirable to ascertain their analytical expres-
sions. The details of this calculation form the subject of this paper.

On the Results of Tide Observations made in June 1834, at the
Coast Guard Stations in Great Britain and Ireland. By the Rev.
W. Whewell.

This paper consists of a statement of certain deductions which the
author draws from such of the registered tidal observations as have
been reduced ; by correcting the times, as far as the methods em-
ployed would allow, and subtracting from each time of tide, tlie

1835.] Philosophical Transactions. 467

time of the previous transit of the moon, in order to obtain the
interval. He infers that the tide is not affected by distant and
general irregularities, but that it is irregular only so far as it is
influenced by causes which operate in the neighbourhood ; as, for
example, the effect of the wind in connexion with the form of the
land. By obtaining means for different localities, the effect of the
disturbing causes may be estimated.

An examination of the results of the time of high water, conducted
by erecting a series of equi-distant ordinates to represent the intervals
of the moon's transit and high water, and drawing a continuous line
through the extremities of these ordinates, shews that the curves
present, in general, the form of that deduced by Mr. Lubbock, from
the London observations ; and, in most instances, the tides of a single
place present the features of agreement with the theory which Mr.
Lubbock has shewn to obtain with such remarkable exactness in the
London tides : that is, the ordinate of the curve has, in the course of
the fortnight, a minimum and a maximum magnitude, so that the
curve assumes the form a>. The amount of flexure is not, however,
the same at all places, as appears from comparing the observations at
Brest, Plymouth, and London. Hence the fallacy of attempting to
deduce the mass of the moon from the phenomenon of tides, as advo-
cated by Laplace.

The force of the moon determines only the amount of the semi-
menstrual inequality. This inequality has a common form, though
differing in amount at each place. If, therefore, we introduce a
local serai-menstrual inequality, in addition to the general one ; the
discrepancies of the curve might be reconciled. These curves appear
flatter at promontaries, and become more so as the tide wave pro-
ceeds. Another cause, viz. the meeting of the tides may, however,
possess some influence in producing this shape. The tide waves must
meet at some indeterminate point : as, for instance, on the coast of
Kent, and at this point the tide is later than it is if we proceed along
the coast, either east and north, or south and west. Still the meeting
of the tides is not a single point, but, in reality, takes place along
the whole coast, from the Isle of Wight to the Downs, and perhaps
to the coast of Suffolk.

The diurnal difference of the height of the tides ranges from two
or three inches to one foot. This difference may be traced as far as
Portland Bill, but from this point the tides are not affected by it.
The tide hour varies very rapidly on rounding the main promon-
tories of the coast, and where the cotidal lines drawn to correspond
with such conditions, are brought near together, the place of high
water moves slowly, so that it is high water at one point while at a
neighbouring point the water is considerably below its greatest height,
which will produce a difference of level and a rapid stream tide.

On certain peculiarities in the double Refraction, and Absorption
of Light, exhibited in the oxalate of chromium and potash. By Sir
David Brewster.

This salt occurs in flat irregular six-sided prisms, the two broadest
faces being inclined to each other like the faces of a wedge, whose

2 H 2

468 Analyses of Books. [Dec.

sharp edge is the summit of the crystal. The broad faces are inclined
upon the adjacent faces at an angle of 64". The crystal is terminated
by four minute planes, equally inclined to the broad face and the axis
of the prism, but two of the faces often disappear. The crystals are
generally opaque, and at thicknesses not much above the 2V th of an
inch ; they are quite impervious to the sun's rays. Their colour by
reflected light is then nearly black ; but their powder, in daylight,
is green, and French ^ray by candle light. In the smaller crystals
te colour is blue, both by reflected and transmitted light. The
refractive index is about 1*605 and 1*506. At a certain small thick-
ness the least refracted image is bright blue, and the most refracted
image bright green in daylight, or bright pink in candle light.
The blue, when analyzed, consists of a mixture of green, and the
green an admixture of red.

At greater thicknesses the blue becomes purer and fainter, and the
green passes into red ; and at a certain thickness the least refracted
blue image disappears altogether, and the most refracted image is_
olive-green. At still greater thicknesses this image disappears also,
and absolute opacity ensues. With polarized light, when the axis
of the crystal is in the plane of polarization, the transmitted light is
green, but when perpendicular it is blue. In solution the double
refraction disappears, but the other appearances are observed as in
the solid state. The crystal excites a specific action on the red ray
between A & B of Fraunhofer ; a sharp and narrow black band being
formed, which constitutes a fixed line in all artificial lights. The
relations of this salt to common and polarized light, may be examined
by placing upon a plate of glass a few drops of a saturated solution
of it in water. If the crystals are slowly formed they will be found
of various thicknesses, each thickness exhibiting a different colour,
varying from perfect transparency through all shades oi pale -yellow,
green, and blue^ in daylight, and through all shades of pale-yellow,
pale-orange, red, and blue in candle-light.

Second Essay on a General Method in Dynamics. By W. R.
Hamilton.

In his First Essay, the author observed, that many eliminations
required by this method, in its first conception, might be avoided by
a general transformation, introducing the time explicitly into a part
S of the whole characteristic function V. In the present Essay he
fixes his attention chiefly on this part S, and to call it the Principal
function. Its properties are more fully developed, especially in
application to questions of perturbation, in which it enables us to
express accurately the disturbed configuration of a system by the
rules of undisturbed motion, if only the mutual components of velo-
cities be changed in a suitable manner.

Continuation of a paper on the twenty-five feet Zenith Telescope,
lately erected at the Royal Observatory. By John Pond.

1835.] Philosophical Transactions, 469

The observations made by means of this instrument have confirmed
the accuracy of the results obtained in determining the place of any
star passing the meridian near the zenith.

We have now three methods of observing this : 1st, By the mural
circles : 2nd, By the zenith telescope, used alternately east and west,
and 3rd, by means of a small subsidiary star.

Geometrical Investigation concerning the Phenomena of Terrestrial
Magnetism. By T. S. Da vies.

The present series of papers is chiefly intended to deduce the ma-
thematical consequences of the theory of two poles situated arbitrarily
within the earth, and especially to investigate the singular points
and lines which result from the intersection of the earth's surface
with other surfaces related to the magnetic poles, especially the points
at which the needle is vertical, the lines of equal dip, the Halleyan
lines, the isodynamic lines and the Hansteen poles. He investigates
at length the hypothesis of the duality of the terrestrial magnetic
poles, and shews that the question cannot be determined definitely
until the dipping needle is brought to a greater state of perfection
and the influence of geological and meteorological sources of distur-
bance can be accurately appreciated.

Researches towards establishing a theory of the Dispersion of
Light. By the Rev. Baden Powell.

For an abstract of this paper vide p. 147 of the present volume of
the " Records."

Meteorology.

On the Atmospheric Tides and Meteorology of Dukhun, (Deccan),
East Indies. By Lieut. -Colonel W. H. Sykes.

This is a paper of great interest, as it contains a mass of facts
accumulated with great labour and care, in a portion of the world
where science, with the exception of botany, has hitherto been almost
unknown. The author, in the first instance, proceeds to describe
his instruments and his mode of proceeding to observation. These
are important points, and deserve an attentive consideration. The
proper mode of mounting meteorological instruments for observations
in tropical climates is particularly adverted to. Ivory scales and
reservoirs are proved to be useless ; the substitution of metals being
absolutely necessary. The conclusions to which the observations
lead are principally as follow : In the Dukhun four atmospheric
tides exist in the 24 hours ; two diurnal and two nocturnal, each
consisting of a maximum and minimum tide. These, as compared
with observations at the Royal Society, are

Diurnal maximum fallinr^
tide from 9 — 10 a.m. to 4 — 5

P.M.

Nocturnal falling minimum
tide from 10 — 11 p.m to 4 — 5

A.M.

Poonah . . — -0181
Royal Society —'0162

Poonah . . — -1166
Royal Society — '0289

470

Analyses of Boohs.

[Dec.

Diurnal 7'ising tide from
4—5 A.M. to 9 — 10 A.M.

Poonah . . + '0445
Royal Society -j- -0185

Nocturnal maximum rising
tide from 4—5 p.m. to 10 — 1 1

P.M.

Poonah . . + -0884
Royal Society + *0272

These tides occur within the same limited hours as in America
and Europe, the greatest mean diurnal oscillations taking place in
the coldest months, and the smallest tides in the damp months of
the monsoon ; while at Madras the smallest oscillations are in the
hottest months, and in Europe it is supposed the smallest oscillations
are in the coldest months. The diurnal and nocturnal tides are
regular whatever the thermometric or hygrometric indications may
be, or w^hatever the state of the weather ; storms and hurricanes
only modifying them. The mean diurnal oscillations at Poonah,
1,823 feet high, are greater than at Madras. At a higher level than
Poonah, the diurnal tides were less, while the nocturnal tides were
greater. The maximum mean pressure of the atmosphere is greatest
in December or January, then gradually diminishing until July or
August, and subsequently increasing to the^ coldest months. The
annual range of the thermometer is less in Dukhun than in Europe,
but the diurnal range is much greater. The annual mean dew point
is higher at 9*^ 30' than at sunrise or 4 p.m. The highest dew points
occur in the monsoon, the lowest in the cold months. The rain in
Dukhun is only 28 per cent, of the rain in Bombay (Records, vol. i.
p. 29J..) ninety or a hundred miles to the east. Fogs are rare, and
are always dissipated by 9 — 10 a.m. Circular and white rain-
bows occur ; solar radiation is very great; the atmosphere is very
opaque in hot weather, and the mirage is distinct.

II. — JVew Works.

1. Lehrbuch der Geologie und Geognosie, von Dr. R. C. von Leon-
hard. V. Lieferung. Stuttgart, 1834.

This work has especial reference to the vicinity of Stuttgard.
The preceding part treats of the general proportions of terrestrial
bodies ; the heat of the earth, with its density and magnetism. The
fifth number comprises the formation of hills and mountains and
vallies, mountain-passes, plains, and the bottom of the sea. The
sixth part will contain an account of air and water, under the divi-
sions of oceans, atmospheric vapour and dew, wells, rivers, seas, ice,
snow, &c. The seventh portion will be occupied with the changes
produced on the earth's surface by the chemical action of water,— the
encroachments of the sea, and action of the atmosphere upon rocks.

2. Lehrbuch der Botanik, von Dr. G. M. BischofF. II. Band.

This volume begins with the anatomical structure of plants; their
vessels, roots, stem, bark, fruit, seed ; and terminates with an account
of their chemical com^iosition.

1835.] Scientific Intelligence. All

3. Resolutio Problematis de circuli Quadratura juxta calculum quern
coUigere potuit Joaquimus Antonius de Oleveira Leitad Presbyter
secularis, 8^c. London 1835.

The author, in this pamphlet, attempts to solve a problem which
has long been given up as incapable of solution, after having en-
gaged the attention of the first mathematicians of every age. Unlike,
however, the Sieur Mathulon, who offered a sum of money, with the
greatest arrogance, to any one who should prove his pretended quad-
rature false, (it consisted in dividing a circle into two quadrants, and
turning these outward so as to form a square), our author tells us
that if he is made sensible by solid reasons that his opinion is erro-
neous, he will willingly submit to the voice of truth. He observes :
" In order that we may the more easily reduce any circle whatever
into a square, we will do it in the following manner : Let us divide
the diameter of the circle into 5 equal parts ; we will take four of
these parts, which will be equal to one side of the square, and which
is equal to the circle in the periphery but not in the space. Let us
then seek a middle proportional line between the diameter of the
circle and that of the square ; and behold the side of another square
perfectly equal to the circle in space."

He very candidly subjoins two refutations by mathematicians of
his solution ; one is, " The square has been divided into 8 equal parts,
and the arc of the quadrant surpasses its cord by i th part. The
radius of the circle is equal to 5 ; but if the square of the cord is
equal to double the square of the radius, it follows, that 7 squares
are equal to the double of 5 ; that is to say, 49=50." This does not
convince our author, but he exclaims : " Ecce nobilis et prseclari
geometrice eruditi, ecce sententia mea quam honorifice censurae ves-
trae submitto ; enim desidero inexhaustum veritatis thesaurum magis
magisque hominibus patefieri; ad quod aliquoties audaces fortuna
juvat.

Article IX.

SCIENTIFIC INTELLIGENCE.

I. — Nature of the Combinations of Alkalies with
Carbonic Acid.^'

POTASH AND CARBONIC ACID.

1. To determine the nature of this compound, Henry Rose placed
4*001 grms. (61*73 grs.) of the crystals of bi-carbonate of potash in a
vacuum over sulphuric acid, for 20 hours. They lost '002 grms.
(•03 grs.) ; 1*427 (22 grs.) of the pounded salt lost, in the same time,
•003 grms. (-046 grs.) The first loss being equivalent to -05, and
the second to '21 per cent.

2. 1905 grms. (29*33 grs.) of the same salt, finely pounded, when
placed under a bell glass on a plate upon which a quantity of caustic

* Poggendorff's Ann. xxxiv. 149.

472 Scientific Intelligence. [Dec.

potash was deposited, lost in 16 hours -009 grnis. {'138 grs.) or 7*25
grs. per cent, and in the succeeding 16 hours -001 grm. ('015 grs.)

3. 0-944 grms. (1453 grs.) of bi-carbonate of potash were dis-
solved in 1 loth ('469 troy ounce) of cold water, and evaporated to
dryness at a temperature of about 60", over sulphuric acid ; the loss
of carbonic acid and water sustained in some days was '06 grms.
(•926 grs.) or 636 per cent.

4. 1-617 grms. (24*9 grs.) of bi-carbonate were dissolved in '939
ounces of cold water, the solution was evaporated in a vacuum over
caustic potash and sulphuric acid. After evaporation the residue was
again dissolved in '46 ounces of cold water, 14 days were occupied
in the process, and the salt was still moist ; the salt was therefore dis-
solved in water, the solution replaced by one of chloride of calcium,
to which some ammonia was added ; the resulting carbonate of lime
was filtered ; it weighed '951 grms. (14*64 grs.) and eontained 6-391
grs. carbonic acid. In 100 parts of the bi-carbonate this amounted
to 25*7 per cent. ; so that, as the carbonic acid in the bi-carbonate
amounts to 43*95 per cent., 1825 per cent, of carbonic acid was dis-
charged. There remains, therefore, some more acid than is necessary
to form a simple carbonate.

5. 2*451 grms. (37'75 grs.) of bi-carbonate were dissolved in 3*75
ounces of cold water ; the solution was placed in a vacuum for 24
hours. The solution treated with chloride of calcium and ammonia
gave 2-211 grms. (34*049 grs.) carbonate of lime, which contained
14-87 grs. carbonic acid. Therefore, 39*43 per cent, of the 43*95
per cent, carbonic acid contained in the bi-carbonate remained in the
solution, and 4*52 were discharged.

6. By repeated evaporation and solution in vacuo, in other trials,
as much as 10*62 per cent, of carbonic acid were given off. He
found that much more carbonic acid was given off when a substance
was placed under a receiver which could absorb the carbonic acid,
than when sulphuric acid alone was used.

7- ,100 parts of bi-carbonate, when boiled at the usual atmospheric
pressure, gave off 11-85 per cent, of carbonic acid, while 32*10 re-
mained combined with the potash.

8. 1*143 grms. (17*6 grs.) dissolved in 21^ ounces of water were
boiled down to 4*69 ounces ; the solution being treated with muriate
of lime gave 24*51 per cent, carbonate of lime.

9. 1*056 grms. (16*17 grs.) bi-carbonate were dissolved in 3*6
ounces of water, and boiled in a retort, to the neck of which a tube
was adapted, and conveyed under mercury, whose height was some-
what more than an inch ; 8*95 per cent, of carbonic acid were dis-
charged. By increasing the pressure the quantity discharged was
smaller.

It follows, from the first and second experiments, that the whole
of the carbonic acid and water of crystallization is so intimately
combined with the potash in bi-carbonate of potash, that the removal
of the atmospheric pressure, either by means of sulphuric acid or
caustic potash, has no influence in decomposing the salt, which, how-
ever, is the case with a solution of the salt in cold water. From the
fifth experiment, we learn that the removal of the atmospheric pres-

1835.] Scientific Intelligence, 473

sure is sufficient to extract carbonic acid from a solution of the salt
at the usual temperature. The way in which sesqui-carbonate of
potash is formed is explained by the sixth and seventh experiments.

Rose has often evaporated a solution of bi-carbonate of potash
in vacuo over sulphuric acid, to obtain sesqui-carbonate of potash as
recommended by Berth ollet. He obtained a mass, of which a part
deliquesced in moist air, while, in the dry portion, crystals of bi-car-
bonate could be detected. The deliquescent mass afforded a precipi-
tate in the cold with sulphate of magnesia. Hence, it contained
simple carbonate. It is, therefore, proper to determine whether an
alkaline carbonate is a simple or double salt by this means.

SODA AND CARBONIC ACID.

10. 1-9705 grms. (30*338 grs.) of bi-carbonate of soda were dis-
solved in 8'442 ounces of water, and evaporated to dryness in vacuo
over sulphuric acid. The discharged carbonic acid was occasionally
removed by the action of the pump. In the solution remained 38*28 per
cent, of carbonic acid, nearly the quantity to form a sesqui-carbonate.

11. The 8th experiment was repeated by boiling 1*26*4 grms.
(19*465 grs.) of bi-carbonate of soda dissolved in water. The solu-
tion contained 31*74 per cent, of carbonic acid. This is a larger
quantity than is contained in the carbonate, and less than is necessary
to form a sesqui-carbonate — the former requiring 26-10, and the
latter 39*15 per cent, of carbonic acid. It appears from this result
and others which Rose obtained, that if the solution were boiled lono-
enough, especially in an open vessel, the bi-carbonate would be com-
pletely changed into carbonate. Soltmann, a large manufacturer,
prepares sesqui-carbonate by evaporating a solution of bi-carbonate,
but never by mixing the bi-carbonate with carbonate. These crystals
are small, and possess the exact shape of trona or native sesqui-car-
bonate ; they are, however, mixed with some carbonate.

12. 0*821 grms. (12*64 grs.) bi-carbonate of soda were dissolved
in '469 ounces of cold water, and at the usual temperature and pres-
sure evaporated over sulphuric acid, the solution being surrounded
with caustic potash; the dried mass weighed 0*666 (1025 grs.) : it
was again dissolved in the same quantity of water and again evapo-
rated. It now weighed -643 grms. (9902 grs.). The solution of
this residue in water gave *564grms. (8*684 grs.) carbonate of lime =
*2465 grms. (3*78 grs.) carbonic acid. The mass consisted of *3043
grms. (4-68 grs.) soda, '2465 grms. (3*78 grs.) carbonic acid, and
•0922 grms. (1 *41 grs.) water. The usual method of determining the
quantity of carbonic acid in mineral waters, it is obvious from these
experiments, cannot be correct. To obtain the true quantity, the
water should be precipitated with chloride of calcium, or rather
chloride of barium, the solution of one of these salts should be added
to the water, along with a quantity of ammonia, and the precipitate
allowed to subside in a well corked flask. The precipitate contains
sulphate and phosphates, should the water contain these acids. Hav-
ing weighed them, after ignition, the sulphate is treated with an

474 Scientific Intelligence. [Dec.

acid, and the phosphoric acid in solution determined. When the
mineral water contains earths and oxide of iron dissolved in carbonic
acid, these will be precipitated by the ammonia. It is, therefore,
best to boil a portion of the water, and to subtract the weight of the
precipitate of earthy and iron carbonates thus precipitated from the
weight of the product which is produced by the ammonia, added to
the solution of the barytes or lime precipitant. Carbonates of lime
and barytes, as must be observed, are not wholly insoluble in water,
and, therefore, the quantities in solution should be appreciated.

II . — Pharmaceutical Preparations.

1. Thb Ballota lanata (Leonurus lanatus, Pers Panzer a mul-
tifidtty Monch), grows in Siberia and China. In Siberia it is used,
according to Pallas, in headache and ascites. Professor Brera re-
commends it especially in ascites proceeding from gout and rheuma-
tism. The best form for administering it is the decoction. This is
formed by boiling half an ounce of the root for a quarter of an hour
with eight ounces of water ; half of this should be taken morning
and evening. — Gazetta eclettica di Farrnacia, Anno iii. 189.

2. The Carragaheen or Irish Moss, (Chondrus crispus) has
been strangely overlooked in this country. On the Continent f/owr/i.
de Chim. Medic j i. 184) it is extensively employed, and forms an
excellent mucilage j in the proportion of 1 oz. carragaheen to 3 lbs.
water. The mixture is to be boiled for 15 or 20 minutes in a basin
over a slow fire, and then withdrawn and passed rapidly through
linen. Although it contains only 1 in 30 parts of the sea- weed, yet
it possesses as much consistence as the mucilage of gum arabic, with
ten times as much gum. It is not precipitated by alcohol, which is
the case with gum-arabic and Iceland moss. Irish moss is an analeptic,
and is used in pthisis, general debility, as well as in dysentery
and chronic diarrhea, either in the form of decoction or jelly.
The jelly is formed by mixing .5 ounces of the mucilage with 4
ounces of lump-sugar, and boiling down to 8 ounces. When cooled
it forms a jelly of fine consistence. The analeptic milk of Thodunter
is made of 24 ounces of cow's milk, 4 scruples of Irish moss, white
sugar an ounce, bruised cannella 1 scruple. Boil for 10 minutes, and
express. When cooled this jelly may be used at table, and eaten
with cream.

The Chondrus crispus grows plentifully on our coasts, especially
in Ireland and Scotland; and is used as a jelly in the former country.
The frond is dichotomous, plain ; margin, entire ; segments spread-
ing, linear, with bifid apices ; capsules, subhemispherical, imbedded in
the disk of the frond. It grows in tufts, from two to four inches
high. — {Johnston's Flora of Berwick).

3. In some Pharmacopeias, instructions are given to rectify spirt-
tus etheris nitrici over calcined magnesia. Rottscher, apothecary
at Wiedenbriick, prefers caustic potash, in the proportion of 80 ounces
of spirit to 4 ounces of solution of caustic potash. The distillation

1835.] Scientific Intelligence. 476

goes on quietly, and no prussic acid is formed. — Brande's Pharm.
Zeit, 16, 251. 1835.

4. According to the plan recommended by the Pharmacopeia
Belgica, when the muriate of iron is dissolved in water a consider-
able residue remains. Kop adopts a method of preparing this salt
which renders it completely soluble. He dissolves the oxide of iron
in muriatic acid, evaporates the solution in a glass flask upon the
sand-bath, till it acquires such a consistence as to solidify when drop-
ped upon a cold body from a glass rod. The flask is then taken from
the sand-bath and allowed to cool. The mass is completely soluble
in water ; the solution possesses a blackish colour. — Mulder's Na-
tuur en Scheikund, Arch. i. 287.

5. Aqua Binelli. — Numerous trials have been made in Germany
by Dr. Kosch to determine the hemorrhages in which this styptic is
peculiarly efficacious. The conclusions come to are, that it answers
well in parenchymatous bleedings, and for hemorrhages during opera-
tions, especially of tumors where a number of vessels are opened ; a
piece of lint dipped in the preparation is to be introduced into the
wound. It is also very useful in bleedings from the diseased vessels
of old persons, or cachechtic individuals, and where the bleeding
vessels are so deeply situated that they cannot be isolated. — Grdfe
and Walther's Journ. fur Chir, und Augenheilkunde, xx. 586.

III. — Statistics of Geneva.*

According to M. E. Mallet, the plague, or at least a disease bearing
that name, in the Genevese Annals, appeared first at Geneva in 1012,
where it is said to have carried off" 4,000 persons. In 1349 it pre-
vailed over almost the whole known world ; — 6,000 persons died of
it in Geneva. It shewed itself likewise in 1473—90—92, 150-3 — 04
— 05, & — 29. Indeed, it appears to have scarcely left the city for
many years about this time. In 1530 it was suspected that a man of
the name of Caddoy extended the disease by dipping rags in the
matter of the boils and throwing them in the street. He was put to
death on this account. It appeared again in 1542, — 43, — 45, — 68,
—69,— 70,— 72. In 1596 it carried off" 4 persons; 1597, 14; 1598,
178; 1599, 77- In 16 15 it began in July and ceased in January
following, and destroyed 1,648 persons. In 1628 19 people died of
plague; 1629. 158 persons; 1630, 117; and 1631, 15 people.
The last plague began in 1636, when 575 people died; in 1637,
178; 1638,347; 1639, 221; 1640, 122. Since 1640 the plague
has not re-appeared at Geneva.

If we take the whole population at 15,000, from 1630 to 1640,
the mortality from the plague is 1 in 52 persons. The mean of the
deaths from the same disease above the usual mortality is 34-6 per
cent. With regard to the ages of the persons who died, the mor-

• Bibliotheque Universelle, January 1835.

476 Scientific Intelligence. . [Dec.

tality at 9 years of age was more than double the usual mortality at
the same age; from 10 to 25, more than triple the ordinary mor-
tality ; from 40 to 50, not half greater ; while at 60 it is less, and at
70 it is more than half less than the usual mortality ; and at 80 infi-
nitely less. Hence, the plague appears not to be a dangerous disease
in advanced life. This is exactly the reverse of the mortality in
cholera. While typhus is most common between the years of 20 &

40 ; it rarely occurs above 40. From 1 year of age to 80 the deaths
from cholera are to those from plague as 1 to 7 ; from 30 to 80 the
proportion is reversed; — the mortality from plague being to that
from cholera as 1 to 8.

In 1834, according to the census, the population of Geneva con-
sisted of 12,573 males, 14,604 females = 27,177 total. In February
1828 the population was 11,978 males, 14,143 females = 26,121
total. Shewing an increase of ^- in six years.

1. The births in 1834 were : males, (legitimate, 281 ; natural,
17,) 321; females, (legitimate, 304 ; natural, 23,) 304. Total,
625. The proportion of births to the population is 1 to 43*48. The
illegitimate children amount to 6*4 per cent. There were six cases
of twins, viz. 2 with 2 boys, 1 with 2 girls, and 3 with a boy and
a girl.

2. Still horn : Males (legitimate, 27 ; natural, 2,) 29 ; females,
(legitimate, 10; natural, 3,) 13, or -J^th of the births.

3. Marriages: Between previously unmarried persons, 187
young men and widows, 7 ; divorced men, and young women, 2
widowers and young women, 24 ; widowers and widows, 7 = 227
or 1 marriage for every 120 persons.

4. Divorces = 3 ; 2 from assigned causes, and 1 by mutual
consent.

5. Deaths: ikfaZe^, young men, 168; married, 103; widowers,
49 = 320 = 11920, eight years together. Females: young
women, 146; married, 86; widows, 81 = 313 =: 13,043, four
years. Total of both sexes, 633.

Of these 92 or i died in the hospital (60 males, or ^, and 32
females, or ^.) The proportion of deaths to the population is
1 to 42-93.

The mean term of life for men is 37 years 3 months ; for women,

4 1 years 8 months 2 days ; both sexes, 39 years 5 months 7 days ;
and the probable term of life for men is 38 years ; for women, 45
years 3 months; both sexes, 41 years 4 months 15 days. The num-
ber of suicides investigated are T, viz. 2 men by means of cutting
instruments, 1 man by fire-arms, 3 women by throwing themselves
from a height, and 1 man by drowning. No person died from
small pox. There were 264 vaccinations ascertained.

6. Proportion of deaths to births. — Males, births, 321;
deaths, 320 = + 1 excess of males. Females, births, 304 ; deaths,
313 = — 9 = excess of deaths. Total births = 625 ; deaths, 633,
leaving 8 for the decrease in the population.

1835.] Scientific Intelligence. 477

IV. — On Chemical Symbols.

In answer to the observations made upon chemical symbols, at p.
315 of this volume, two communications have been received, one from
a correspondent, whose name I should have wished to have accom-
panied the publication of his observations, and the other from Mr.
Hiley.

1. My correspondent P proceeds,

" Nothing having appeared in your Number just come out, in
accordance with your invitation to discuss some points relating to
symbols : a subscriber sends in the following summary, by way of
commencement, with a view of expediting the tables you promise us.

" The general advantages of chemical symbols may be these. They
exhibit to the eye an atomic analysis of every compound, at once
concise and distinct ; and ultimate, except where organic acids or
bases enter into the composition. This is convenient for tabulating
bodies for comparison ; for exemplifying the changes which take
place in the re-action of compound bodies ; and, which is of more
consequence, obviates the need of circumlocution in our nomenclature,
a difficulty continually increasing with discoveries among the more
complex atomic combinations.

" Their significations are theoretical, and consequently liable to
change, until the true integer atoms shall have been determined; a
consummation of which there is little hope at present, whilst the
thermic atoms of simple bodies come out J, J, or even Jth of those
deduced from analysis (Avogadro Records of General Scieiice,\\. 34.)
and another class of them gives the gaseous volume J of the analytical
atom as compared with oxygen, {ist Prin. ii. 478; and Dumas
Chim. app. aux arts, passim). Whether M. Ampere's distinction
into atoms, molecules, &c., [Ann. de Chim. et de Physique, April
1835), may eventually help to clear the subject, time will show. In
the mean while, it is for us to be content, to have our symbols keep
pace with our atomic knowledge, and that with the progress of
analysis. Our symbols and our terms must change together, and the
objection applies equally to both.

" Conciseness is an object, as far as may be consistent with distinct-
ness ; not only on account of occupying less room, but as more
promptly entering the eye and the mind. And this condition is well
fulfilled by taking the mere initials of the names ; preferring the
Latin, as a common language.

" This gives us, O, oxygenium ; H, hydrogenium ; C, carbon ; S,
sulphur ; but chlorine would again come to C. To distinguish here,
another letter must be affixed ; and CI, for chlorine ; Cu, for copper,
(Cuprum) ; Co, cobaltum ; Ca, calcium ; Ce, cerium ; Cr, chro-
mium, &c. ; adding but little to their length, makes them all clear.

" So far chemists seem now almost agreed ; the doubts expressed
by you, apply to the super-imposed dots; for the atoms of oxygen K O
is not much less concise, and certainly clearer than K ; but K O S O^
is rather confused, and K O + S O 3 a longer formula than K S ;
and when to K O + S O^ + 3 Al O + 3 S 03 + 24 H O is
superadded^ the formula becomes rather formidable compared with

478 Scien tific In telligence . [ D e^ .

* .
k S + 3 Al S + 24 H. The latter has the advantage in distinct-
ness, as well as brevity j the sign + being interposed between the
compounds of the second order (or those and water) not between the
combinations of acid and base ; whilst the common negative element
is placed in circumstances of particular facility of computation, where
the eye perceives its proportions, in the different ingredients, with
hardly an effort of the mind. The law to which this last commenda-
tion applies, Professor Thomson has been at some pains to invalidate ;
but as it holds good in salts containing bases of (M2 O^) as well as
of M (M O) and in the sulpha-salts, and compounds of chlorine, &Co
as well as in the oxy-salts, it seems fairly entitled to the character of
a general law, notwithstanding a few exceptions.

" A little more care, on the part of the printer, the points may
require, thus applied out of their usual place and signification. But
if this objection is intended to hold further than with the printer, it
is anticipated by the mathematicians, in the alternative of the letters
and exponents. K O they say, signifies K multiplied into O ; and
S 03, S multiplied into O cube; and they ought not to be used by
chemists in any other sense . They have, however, already practi-
cally repelled, not only your objections, by using the point equally
out of place, as a fluxivoal sign : but their own, by continually
employing the alphabetic characters, both italic and Greek, without
regard to their proper signification. It remains to be shown why
the chemist should be more restricted.

" These are the chief reasons that occur to the writer for the use
of symbols, and of the particular ones in question. It is needless to
fill your pages with anticipations of objections which may be better
answered if they arise. P."

2. Mr. Hiley urges the mathematical objection against the use of
S 03 preferring S -f 3 O (the type of the numeral exceeding in size
those of the symbols of the elements), and recommending the inter-
position of the positive sign in all cases, as Ba + O for Barytes, and
(Ba + O) -f (C -F 2 0)for carbonate of barytes; N + 50for
nitric acid ; 2 Cu + CI, for dichloride of copper, &c. ; or to those
who " would prefer sacrificing explicitness to brevity," the symbol
(Ba -f C) for carbonate of barytes, might be more acceptable. With
regard to points and commas, his " decided opinion is, that they ought
to be laid aside." They bear no similarity, he continues, " to the
other symbolical expressions with which we are acquainted. They
are like nothing in algebra or other parts of mathematics, or at all
events, wherever signs of this nature have been used, their applica-
tion is entirely different, and moreover, their positions vary. The
dot when employed in algebra, is placed alongside the symbol, as a.
b. c, and indicates multiplication. Whereas, when chemically ap-
plied, its situation is over the symbol, and is indicative of addition.
As in algebra the vinculum in the shape of a parenthesis is preferred
to the long line drawn over each of the compound factors : so in the
case of symbols, initial letters and figures are more eligible than points
and commas."

* This symbol for alumina accords with Thomson's atomic system, not that of
Berzelius. 1 do not t-ive it as the true one.

1835.]

Scientific Intelligence,

479

V. — Weather at Madras.

Mean height of the Thermometer and Barometer during the North-
East and South West Monsoons, between vl 796 and 1821 ;

NORTH-EAST MONSOON BETWEEN 1796 & 1821.

Months.

Thermometer.

Barometer.

Ruin in inches

from
1803 to 1825

October

November ....
December ....
January ....
February ....
March

81-858
78-672
75-843
75-168
77157
79 920

29-942
29-956
30-074
30085
30076
30-041

12-273

13-937

7-522

0-737

0-099
0-469

78-103

30-029

NORTH-WEST MONSOON BETWEEN 1796 & 1821.

Months.

Thermometer.

Barometer.

Rain in inches

from
1803 to 1825.

April

May

June

July

August

September. . . .

Difference .

82-471
86-918
88-159
85-645
84-732
83-825

29-955
29 851
29 861
29-867
29-879
29-908

0333
1-354
0-854
2-945
3883
4-359

85-283
78.013

29-887
30-029

48-755

7180

0142

Mean height of the Thermometer from 1796 to 1821, 8r-700

„ Barometer „ 29-964 in.

The hottest day, by the mean of observations made during twenty-
one years, is the l5th of June, when the mean heat of the thermo-
meter w^as 89^-19 ; the mercury varying from 95 -1 to 81^*6

The greatest heat was 104 i; the minimum heat 64"^. The
hottest part of the day is about j hour past noon ; the coolest period
is about half after 4 in the morning ; and the mean temperature at
7 in the evening and 9 in the morning. — Trans, Royal Asiatic
Society y vol. iii. 17.

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A.M. wind gusty, P.M. calm, with rain.

A.M. brisk wincl, cirri and cirrostratus prevalent, P.M. overcast and calm.

Calm, sky overspread witli clouds of the cirrostratus and the cirrocumulus

Strong wind, with continual rain. [formation.

Calm, cloudy, and for the most part lowering.

Calm, A.M. rain, P.M, lowering, with occasional showers, evening cloudy.

Calm, A.M. heavy clouds with showers, P.M. gradually clearing, ev. cloudless.

Calm, cloudy with occasional showers, evening rainy. [copious deposition.

Calm, occasionally cloudy, tendency to rain, cirri and cirrostratus prevalent.

Brisk wind, cirri and cirrostratus prevalent, sky often assumes a stormy aspect.

Brisk wind, A.M. lowering, P.M. large masses of cloud floating over hazy sky .

Brisk wind, 8 A.M. light rain, cirrostratus prevalent, evening calm.

Brisk wind, interrupted by calms, cirrostratus with tendency to cymoid forma-

Calm, same general character as yesterday. [tion, evening clear.

Very calm, cloudy, with tendency to rain.

Very calm, cloudy, occasionally lowering.

Very calm, cloudy, occasionally lowering.

A.M. gentle wind, sky overspread with soft hazy clouds, P.M. calm, lowering.

Gentle wind, cirri and cirrostratus, with tendency to cirrocumulus, evg. clear.

Calm, cloudy, cirrostratus prevalent, evening raiia.

Calm, A.M. overcast with tendency to rain, P.M. partially clear, deposition.

Brisk wind A.M. cirri and cirrostratus, P.M. hazy clouds, evening rainy.

Gentle wind, nearly cloudless ; evening, the winci rising and rain.

A.M. brisk wind, P.M. calm, heavy masses of cloud on a blue sky, evg. clear.

Hoar frost, very gentle breeze, overcast and lowering, evening rainy.

Boisterous wind, with very heavy rain, P.M. wind less boisterous, evg. clear.

Calm, cirri abundant, with beds of thin cirrostratus, evening clear.

Very calm, cirri and cirrostratus, and in the afternoon polarized from N. to S.

Brisk wind, cirrostratus and cirrocumulus prevalent, evening calm and clear.

Very calm, cirrostratus tendency to cymoid formation, polarized from E to W.

Very calm, A.M. foggy (stratus) P.M. hazy clouds floating, evg. deposition.

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Direction
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at
X. A.M.

S.E.byE.

S. W.

W.N.W.

N.

W. N.W.

N. E.

N. by E.

SW.byW

W.N.W.

W.N.W.

NWbyW

W. N.W.

W.

W.

W.

S. E.

S. E.

SW.byW

S. S. E.

W.N.W.

W.N.W.

S. E.

W. S. W.

W.byS.

S. W.

NWbyW

NWbyW

S.

s. w.

s. w.

W.byS.

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in
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Weekly.

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y 0-312

y 0-396

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INDEX

PAGE

Aberdeen, Standard scale of . .215
Accidental colours, on . 21, 179, 283
Acrospire . . . . 298
Agassiz, M. on fossil fishes . .193
Alcohol, action of electricity on,

&c. .... 143, 144
Aldeide .... 155

Alkalies, combinations of carbonic

acid with . . . .471

Allan's Saccharometer . . 459
Almagest of Riccioli . . . 339
Alumina, racemate of . .168

sulphate of and iron . 55

America, severity of winter in . 76

patents . . .74

Ammonia muriate of, action of on

sulphates .... 152
Anemometer, on a new . , 218
Anatase, new locality for . . 314
Animalcules, natural history of 143
Animal heat . . . .371
Antimony, potash racemate of . 251
Apjohn, Dr. his formula for speci-
fic heats 202

Aqua Binelli . . . .475
Arabia, plants of . . . 398

Arabic gum, properties of . 319
Arkansas, Flora of the . . 74

Arsenic, in English sulphuric acid 73
Ashmolean Society of Oxford, pro-
ceedings of . . . , 145
Atomic weights, relation of speci-
fic heats to . . . . 34
Association, British, proceedings of 186
Avogadro, M. on specific heats . ib.

Babbage, Mr. on a whirlpool at

Cephalonia .... 235
Backs, under, for distillation . 459

wash, for do. . . , 462

Bakerian, lecture by Mr. Lyell . 388
Balard, A. J. on the decolourizing
combinations of chlorine 262, 341,
425.
Ballota Lanata, used in medicine 474
Baltic Sea, temperature of . 237

Baltynite 451

Barometers, altitude . , 384

• description of . . 383

■ easy method of filling 440

horary observations of 399

Barytes, bi-calcareo carbonate of . 314
■" racemate of . .163

tartrate of . . . ib.

Bells, tones of . . .130

Bentham, Mr. on hydrophylleae . 307
Biography of Gillet de Laumont 75

Baron Dupuytren . 81

Rev. J. Flamsteed 321

Bird, remarkable flight of a . . 318
Bleaching powder, composition of 435
Blood, action of galvanism on . 20

examination of . . 15

Blue, velvet copper . . 315

Botany, introduction to . 64, 470
Botanical Section of British Asso-
ciation .... 311
Boussingault, M. ascent of Chim-

borazo . . . .45, 252
Brewster, Sir David, theory of Ac-
dental Colours . . .182
■ — on optical properties of
potash oxalate of chromium . 467
Bridewell, Glasgow, state of . 313
British Association, proceedings of 186
Brockeden, Mr. on Alpine storms 72
BufFy coat of blood . . .18
Burdiehouse, fresh water lime-
stone of 68

Bunsen, Dr. on ferro-cyanodides 386

Cadmium, racemate of . . 242
Capnomore . . . ,79
Carragaheen, or Irish moss, an ana-
leptic 474

Carbon, specific heat of . . 37
Carbonic acid, combinations of with

alkalies 471

Carbydrogen, or pyroxylic spirit 374
Carnages, steam on . . 230
Castleton, state of religion in , 331
Chabasite, optical properties of 200
Charae, evaporation of . . 155
Chemistry, section of . . 195
Chimborazo, ascent of . , ,45
Chlorides, specific heat of . 42
Chlorine, decolourizing combina-
tions of 262

Chlorous acid gas . . . 347
' aqueous solution of . 341

preparation of . . 268

composition of . , 425

Chondrus crispus . . , 474
Chromium, potash oxalate of . 467
Chyle, examination of . . 20
Circle, on the quadrature of ,471
Cistocircus tenuicoUis a hydatid 310
Cobalt, racemate of . . .241

Codeine 382

Coins, value of ancient ., . 146

482

INDEX.

PAGE

Collision of beams, on . . 219
Combustion, spontaneous, cases of 119

Comet noticed by Flamsteed . 137

Complementary colours, on 179, 283

Coolers, for distillation . .461

Copal, different kinds of . . 306

Copper, blue velvet . . . 315

Coppers, in distillation . . 458

Dalton, Dr. on spirit from caout-
chouc 200

on chemical sjnnbols 203

• on combustion in lamps 201

Darwin, Dr. theory of accidental

colours 181

Daubeny, Dr. on Vesuvius . 390

on the absorption of

plants 149

on sublimation of

ma^esia .... 200

Davy, Mr. E.on corrosion of iron

by sea-water . . .195

on nicotine . 204

Decandolle, introduction to botany 64

on the larch . . 72

De Godart's theory of accidental

colours 183

Denham, Lieut, on the estuaries of

the Dee and Mersey . . 192
Diopsis, a genus of insects . . 308

Diorite 272

Dioritic porphyry . , . 275
Donne, Dr. on secretions . 156

D'Orbigny, description of a new

animal by . . . .76
Dublin, arrival of Flamsteed at 329

Foundling hospital . .312

meeting of British Associa-
tion at 186

Dupuytren, Baron, biography of 81
Dye, new yellow, for wool . . 158
Dynamics, general method in . 468

Earthquakes since 1821, list of
at Basle

385
386

Eclipse of the sun in 1666 . . 3S7
Electricity, Dr. Faraday on . 465

■ passage of, through

liquids 393

Electrical relations of metals . 465
Ether, theory of . . . . 144
Ettrick, Mr. on an improved safe-
ty lamp 196

Esculic acid .... 158
Excise Committee of the Royal
Society 391

Fairy stones, description of . . 1

Faraday, Dr. on electricity . 465

on sound . .71

Fat, goat, composition of . . 156

Ferro-cyanodides and ammonia 386 ,

PAGE

Fibrin, action of saline solutions on 365

in blood . . .16

Flamsteed, Rev. John, life of . 321
Floating bodies, on . . 212, 401
Flooring, malt, process of . . 297
Fox, Mr. on a dipping needle . 2l5
on electrical relations . . 465

Gabbro . . ' . . .444
Geneva, statistics of . . 475
Geological Section of British As-
sociation .... 188
Germany, Scientific Association of 237
Goat fat, composition of . . 156
Gold, chloride of, a caustic . 398

iodides of . . . . 206

Graham, Mr. on water as a consti-
tuent of salts . . . .198
Greatrackes, Mr. a quack, account

of 328

Greenstone rocks, species of . 272
Griffiths, Mr. Geological map by 188
Gums, nature of . . . .319

Hall, Colonel, ascends Chimborazo 47
Halley's comet, Mr. Browne on 148
Hamilton, Dr. his commentary . 304

Mr. on Dynamics . 468

theory of logologues 215

annual address by 224

Harris, Mr. on an electrometer . 202

on electrical attraction fill

— on laws of diffusion . 207

on thermometers . 216

on torsion balance . 213

Heat, on . . 150, 208, 210, 211

animal, on . . . .371

Heart, sounds of the . . 309
Herculaneum, date of its destruction 146
Hibbert, Dr. on fresh water lime-
stone 68

Hodgkinson, Mr. on collision of

beams 219

Humboldt, Baron, letter from . 237
Hydrometer, report on . . 391
Hydrophylleae, natural order of, . 307
Hypersthene rock . . . 277
Hypochlorous acid . . . 431
Hypochlorites . . . 432

Inia boliviensis, new animal . 76
Ink permanent in air . . . 398
Iodide of potassium and bicyanide
of mercury, a test for munatic in
prussic acid .... 205
Iodine with palladium and iridium 77

specific heat of . .39

Ireland, geological map of . 188
Iridium, massy .... 317
Irish gentleman, an anecdote of 337
Iron, racemate of . . . 169
■— ■— hot air used in smelting . 151

INDEX.

483

PAGE

Iron peroxide of, separated by
acetate of potash . . . 205

Johnson's, Mr,, optical investiga-
tions 142

King's, Mr. notes on the life of
Dupuytren .... 82

Larch, diseases of the . . .72
Laumont, Gillet de, biography of 75
Lardner, Dr. on railroads . 220

r- steam carriages . 230

Lead pipes corroded by electrical

agency .... 205

Light white, composition of

27, 351, 108,. 172

voltaic on . . . . 213

Lime, racemate of , . . 105

acetate of . . . .134

Linnean Society, transactions of 304
Lloyd Professor, magnetic obser-
vations by . . * . 218

Logologues, theory of . .215
Lyell, Mr. his Bakerian lecture . 388
Lymph, nature of . . . 15

Madder, dyeing .... 452

purple . , , 454

Madras, weather at . . . 479
Magnesia, carbonate sublimation of 201

medicated liquid . 74

j-acemate of. , .167

Magnetism terrestrial . 213, 384

as amoving power 214, 469

Magnetic lieedle, variation of at

Berlin 384

influence by electricity . 385

observations in Ireland 218

Manganese sesqui-sulphate of . 369

racemate of . . 171

Malt, on .... 295

Malabaricus hortus.. commentary

on 305

Margarine . . . . 156
Manchester, education at . .312
Martinet's pathology . . 390
Mash-tun, description of . . 458
Mathematics, section of . . 206
Matthews, Charles, his thigh-bone 311

Meconine 382

Megalychthys Hibberti . . 69
MeUoni, M., his experiments on

heat . . . . . 150
Mercury, racemated sub-oxide of. 248
ammonia ferro-cyanodide

of 387

Metals, dilatation of, by heat . 154
Mill for grinding malt . . 458
Minerals, specific heat of . .44
Mordants cotton . . . 452
Morphine ..... 382
Miiller, Dr., on the blood . 15

Murchison, Mr., on old strata

PAGE

. 194

Naphthaline, on . . . 314

Narceine 382

Narcotine . . . . ib.
Needle dipping, on, a new one . 215
Newton, Sir Isaac, extraordinary

conduct to Flamsteed . 419, 423
Nickel, racemate of . . . 171
Nuttall's flora of the Arkansas . 74

Opium, analysis of

. 380

Optical investigations

. 142

Orbits, varying theory of .

. 219

Oxides, specific heat of .

40

Paper, making, from turf .

. 204

Papyri, Mr. Twiss, on .

. 150

Paramorphine

. 316

Pathology, manual of

. 390

Pectic acid

. 153

Perichromascope, a new instrument 25
Pharmaceutical preparations . 474
Phillips, Mr., on the fall of rain . 216

fossil astacidae 190

Plants, absorption of . . 307

of Arabia . . . 398

new method of drying . 74

Changes in the inferior

order of 62

Plateau, M,, on accidental colours 281
Plumula, on the . . . 298
Poisoning, cases of, in France . 154
Potash and soda, separation of 11, 398

with carbonic acid . 471

Powell, Mr., on dispersion of light 232

Cauchy's theory . 147

two kinds of heat 150

Prieur, M., theory of accidental

colours .... 182
Prinsep, Mr., on dilatation of

metals ..... 154
Pritchard, Mr. A., on measuring

prismatic spectra . . .122
coloured impressions

of engravings .... 143
Priickner, M., on pyroligneous

acid 133

Pseudomorphine . . ,316

Pulse, experiments on . . 310
Pyroligneous acid, preparation of. 133
Pyroxylic spirit, composition of 374

Quain, Dr., edition of Martinet's

pathology .... 390
Quinine, phosphate of . . 153

Racemic acid, on . 97, 241, 164
Railroads, Dr. Lardner on . 220
Rain, fall of . . . . 216
Rainy, Dr., on the action of saline
solutions on fibrin . 365

484

INDEX.

PAGE

Richleian tables . . . .358
Riccioli's Almagest . . 339

Rio Bamba, beautiful scenery of . 46
Rose, G., on greenstone rocks 272, 444
Ross, Sir John, on the aurora

borealis . . . .210
Royal institution, lectures at .71
Rumminanta, bones in the heart of 310
Russell, Mr., on floating bodies . 212

Saccharometer of Dr. Thomson

Salts, specific heat of

ScherfFer's theory of accidental
colours .....

Scanlan, Mr., on spontaneous com-
bustion ....

Scott, Sir Walter, quotation from .

Secretions, chemical nature of .

Senegal, gum ....

Serous secretions, nature of

Serum, of blood . . . .

Shells, recent marine, found in
Sweden ....

Silver, racemate of .

Soda and potash, separation of .

tartrate of .

racemate of . . .

chloride of, use in fever

with carbonic acid .

Sound, interference of

Spain, geology of .

Spectra, on measuring .

Spectrum ....

Specific heat of gases .

Spirits, process of making

Starch

Standard measure . . .

Stones, fairy, on .

Stockholm, deposit of shells at .

Strontian, racemate of .

■ — tartrate of

553
43

180

119
1
156
319
157
18

388

249

11

162

161

309

473

219

194

122

33

202

457

301

215

1

388

164

ib.

Sulphuric acid a sulphate of water 198

English, arsenic in 73

Sulpho-methylic acid . . . 197
Sulphurets, specific heat of . 42
Sweden, rising of land in . .388
Symbols, chemical, on . 203, 315, 476

Taraxacum officinale . . 397
Telescope zenith, on the . . 468
Thebaine . . . .381

Thomson, Dr. R. D., examination
of hair salt . . . .55

PAGE

Thomson, Dr. R. D. compo-
sition of white light, note on 179

on malt 295

Dr. Thomas, on urine . 3

racemic

acid ... 97, 161, 241

sulphate of manganese

399

bleach-

ing powder .... 435
Tide observations, on the results of 466
Tides, atmospheric, in Dukhun 469
Tin, racemate of . . . 244
Toad, live, imbedded in stone . 235
Tobacco, Virginian . . . 204
Tonjliuson, Mr. C, on visible vi-
bration 124

accidental

colours .... 21,283
Trap dykes, on . . .190
Trail, Dr., on Spain . . .194
Tuns, fermenting . . . 462
Turner, Dr., on atomic symbols . 198

Uralian district, iron works in . 79

Uralite 451

Urea, quantity in urine . , 8

Urine, analysis of . . .3

Verschoyle, Archdeacon, on trap

dykes 190

Vesuvius, eruption of . . . 390
Vogel, on arsenic in sulphuric acid 73
Volcanic eruptions, list of . 385
Volvox globator . . ,78

Wallace, Rev. J., meteorological

journal 80, 160, 240, 320, 400, 480
horary obser-
vations . . . 1i60, 399
Water as a constituent of salts . 198

specific heat of . . 39

Westwood, Mr., on the genus

Diopsis 308

Wheat, composition of . . 295
Wlieatstone, Mr., on voltaic light 213
Whewell, Mr., on our knowledge
of electricity .... 206

on the tides . 466

Wichtine, a new mineral . . 397

Zinc preserves iron from sea water 196

tin plate ib.

racemate of . . . 242

ERRATA.

Tp 13, / 12, for 23-41, read 234*1. p 33, bottom, insert after screen, placed at i /
*<rhen the spectrum is received upon a screen, p 34, / 13 from bottom, andthrough-
,^ut/or Avogrado read Avogadro. p 203, / 20, for 0-0694, read -9722, and vice
[versa, p 205, / 6, for pyroacetic, substitute pyroxylic, and vice versa, p 242 I 4,
for solution, read saturation, p 24"3, / 19, for saline, read silky, p 247, I 24, for
washing, r«arf wanting. |> 250, / 14, /or pressure, rcarf presence, p 296, I 23,
for the last sentence, read " The circumstance of the evolution of carbonic acid in
this first stage, shews us that it forms the preliminary step to germination." p 316
for freezes, read fuses.

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