S.iA^^

JOURNAL .

OF

NATURAL PHILOSOPHY,
CHEMISTRY,

AND

THE ARTS.

• VOL. XXIX.

3ltlusttateD initfj (iBngraiaingiS.

BY WILLIAM NICHOLSON.

LONDON:

FnnrrEO BY \v. stratford, crowh coimr. templs ulri for

W. NICHOLSON,

No. IS, BLOOMSBURY SQUARE;

AND SOLD BY

J. STRATFORD, No. 112, Holboun Hill.

181L

PREFACE.

iHE Authors of Original Papers and Communications in the
_ present Volume are Mrs. Agnes Ibbetson ; J. J), Maycock,
Esq. ; Mr. G J. Singer ; Mr. E. Lydiatt ; Mr. John Davy ; W. Crane,
Esq. F. R. M. S. Ed. ; Mr. R. Lyall, M. R. P. S. E. &e.; R. L.
Edgeworth, Esq. F. R. S. M. R. I. A. ; L. O. C ; T. A. Knight,
Esq. F. R. S. &c. ; Mr. J. Dalton ; the Rev. J. Blanchard ; J. Clarke,
M. D.; Mr. J. T. Price; Mr. St. Amand; T. Forster, Esq.; Mr.
J. Murray ; Marshall Hall, Esq. ; W. Moore, Esq. ; Mathema-
ticus ; Mr. B. Cook ; W, N. ; Zeno.

Of Foreign Works, Messrs. Gay-Lussac and Thenard; M.
Begnier ; M. Van Meerten ; M. Stratingh ; M. Cagniard Latour ;
M. delaChabeaussiere ;Mr.G. B, Sage ;M.Bucholz ; M.Daubuisson ;
M. Cordier; Dr. B. H. Tarry; M. C, Dumeril; M. L. Cordier;
M. Hassenfratz.

And of British Memoirs abridged or extracted, T. Thomson,
M. D. F. R. S, E. &c. ; the Rev. J. Bremner ; T. A. Knight, Esq.
F. R. S. &c. ; H. Davy, Esq. LL. D. Sec. R. S. Prof. Chem. R. I.
F. R. S. E. ; Mr. E. Smith; Mr. J. Hutton, junr, ; H. P. Lee, Esq. ;
the Rev. J. Hall; Mr. T. Balls; Mr. J. Bkker; Mr. W. Jeffery ;
Mr. J. Davis; Mr. W. Moult; Mr. B. Smith; Mr. J, Taylor; B.
C. Brodie, Esq. F. R. S.

The Engravings consist of 1. Dissections of Plants, illustrating
the Growth of the Bud, by Mrs. A. Ibbetson. 2 Crystals of Al-
lanite, by Dr. T. Thompson. 3. Instruments for measuring the
Velocity of Rivers, by Mr. Regnier. 4. Method of covering a
Roof wfth Flagstones, by R. L. Edgeworth, Esq. F. R. S. M. R. I. A.
5. A Ship's ordinary Boats converted into Lifeboats, by the Rev.
J. Bremner. 6. A Barometer with an adjusting Scale, and 7.
An Airpump for producing a perfect Vacuum, by a Correspon-
dent. 8. Section of a Grapehouse, by T. A. Knight, Esq. F. R.
(.. and H. SS. 9. Figures to illustrate the Formation of the Leaves
of Firs, and their Fructification, and the Motion of the Flower
of the Barberry ; delineated by Mrs. Agnes Ibbetson. 10. A Dia-
gram illustrating the Radiation of Cold, by Marshall Hall, Esq.
U- Diagrams illustrative of the Motion of Rockets, by W. Moore,
Esq. 12. A new Thrashing Machine, invented by H. P. Lee,
Esq. 13. A Screw adjusting Plough, by Mr. Thomas Balls. 14.
An improved Implement for extirpating Docks and Thistles, by
Mr. J. Baker. 15. A pair of expanding Harrows, by Mr. Wm.
Jeffery. 16. Mr. J. Davis's Fire-escape. 17. Mr. W. Moult's
Filtering Apparatus. 18. Mr. B. Smith's Method of Relieving a
Horfe, that has fallen in the Shafts of a loaded Cart. 19. Mr. J.
1 aylor's Extractor of ^oul Air from Mines, &c.

TABLE

TABLE OF CONTENTS

TO THIS TWENTY-NINTH VOLUME.

MAY, J811.

Engravings of the following Subjects: 1. Dissections of Plant?, illustrating the
Growth of the Bud, by Mrs. A. Ibbetson. 2. Crystals of AUanite, by Dr.
T. Thompson. 3. Instruments for measuring the Velocity of Rivers, by Mr.
B^egnier.

I, On the Interior of Plants. Letter II. By Mrs. Agnes Ibbetson I

n. Observations on the Hypothesis, which refers chemical Affinity to the elec-
trical Energies of the Particles of Matter. By J. D. Maycock, Esq. Com-
municated by the Author - - - - 12

III. Observations on the igniting, or Wire-melting Power of the Voltaic Bat-
tery, as proportioned to llie Number of Plates, employed ; with an Account
of some Experiments on this Subject, made in Conjunction with Mr. John
Cuthbertson; by Mr. John Singer, Lecturer on Chemistry and Natural PhU
losophy. Communicated by Mr. Singer - - 29

rV. On the different Forces with which Tubes, Bars, and Cylinders adhere to
a Magnet. In a Letter from Mr. E. Lydiatt - - 34

V. An Answer to Mr. Murray's Observations on the Nature of Potassium and
Sodium: by Mr. John Davy - - - , 35

VI. On the Nature of Oximuriatic Gas, in reply to Mr. Murray. By Mr.
John Davy ----- 39

VII. An Attempt to answer the Queries proposed by F. D. in ihe Journal for
April last: b) William Crane, Esq. F. 11. M. S. Edinburgh - 44

Vin. Experiments on AUanite, a new Mineral from Greenland; by Thomas
'ihomson, M. D. F. R. S. E. Fellow of the Imperial Chirurgo-Medical'
Academy of Petersburgh - - - - 47

IX. Observations on Three Papers of Mr. Davy. By Messrs. Gay-Lussac and
Thenard - - - - - -- 59

X. Observations respecting the Sensible Perspiration of the Dictamnus Albus^^
or Fraxinella: by Mr. Robert Lyall, Surgeon, M, R. P. S. E., &.c. com-
municated by the Author - - - ' -^ 67

XI. Description and Use of a Kheumameter, to estimate and compare the Ve-
locity of the Current of Rivers: by Mr. Regnier, Conservator o<^he ctntral
Museum of Arulirry - . - - ^ 68

Scientific N^ws - - -* - - 72

Meteorological Journal - .- ^ - • - 80

JUNE,

CONTENTS. V

JUNE, 1811.

Enoravings of the following Subjects: 1. Methwl of coveriirg a Roof wU|^
Flagstones by E. L. Edgevvorth, Esq. F. K. S. M. R. I. A. 2. A Ship's
ordinary Boats converted unto Lifeboats, by the Rev. J. Bremner. 3. A
Barometer with an adjusting Scale, and 4. An Airpump for producing a
perfect Vacuum, by a Correspondent. 5. Sections of a Grapehouse, by
T. A. Knight, Esq. F. R. L. and H. SS.

I. Description of a Method of Roofing Buildings securely with Flagstones. By'
Richard Lovell Edgeworth, Esq. F. R. S. M. R. I. A. - 81

II. Method of making any Ship's Boat a Lifeboat, to preserve the Lives of the
Crew in imminent danger; by the Rev. James Bremner, Minister of Walls
and Flota, Orkney Islands - » - - 86

III. On the Scale of the Barometer, and the Construction of an Airpump for
procuring a perfect Vacuum. In a Letter from a Correspondent 105

IV. A Description of a Forcing House for Grapes; with Observations on the
best Method of constructing them for other truits. By T. A. Knight, Esq.
F. R. S. &c. - ... . 100

V. On some of Uie Combinations of Oximuriatic Gas and Oxigen, and on the
Chemical Relations of these Principles to Intiaminable Bodies. By Hum-
phrey Davy, Esq. LL. D. Sec. R. S. Prof. Chem. R. 1. F. R. S- E. 1 12

VI. Farther Account of a Mulfe Animal between the Male Ass and Female Ze-
bra. In a Letter from Thomas Andrew^Knight, Esq. F. R. S. &c. 12T

VII. Remarks on Potassium, Sodium, &c. ; in Reply to the Commvmications
of Justus. ByJohnDalton - - - ^ 129

VIII. Table of the Rain that fell in various Places in the Year 1810, by the
Rev. J. Blanchard, of Nottingham; with a Meteorological Table for the
same Year, by Dr. Clarke, of that Town - - 134

IX. On the Use of Iron Pipes for conveying Water, and Mode of securing
their Joints. In a Letter trom Mr. Joseph '['. Price - 136

X. On the Invention of the Economical Process for Evaporation ascribed to
Montgolfier. In a Letter from Mr. St. Amaud - - 138

XI. On the Combustion of Ether, and of Metals, in Oximuriatic Gas: by Mr.
Van Meerten, and Mr. Stratingh - - - 140

Xn. Observations in Illustration of Mr. Howard's Theory of Rain. In a
Letter from ' 1 homas Forster, Esq. - _ ♦ - 142

XITI. Observations on Dr. Bostock's Review of the Atomic Principles of Che-
mistry. ByJohnDalton - - - - 143

Scientific News - - .■--. - 151

Meteorological Journal - * - • HO

JULY,

vi CONTENTS.

JULY, 1811.

Enm-avings of the following; Subjects : 1 . Figures to illustrate the Formation of
the Leaves of P'irs, and their Fnicttfication, and the Motion of the Flower of
the Barberry ; delineated by Mr^. Agnes Ibbetson. 2. A Diagram, HKistratr
ing the Raciialion of Cold, by Marshall Hail, Escj.

r. On the manufacturing of Thread, and Articles; reseinbKng Flax, Hemp,
Tow, and Cotton, from the Fribres of the common Nettle. By Mr. Edward
Smith, of Brentwood, Essex r r r • *• •» 161

IT. Description of an improved Reapinghook for Corn. By Mr. Joseph Hutton,
Jun. of llidgway, near Sheffield - - - HI

m. Report of Messrs. De Prony, Charles Montgolfier, and Carnot, to Xhe

French Institute, on the Invention of a new Engine, by Mr. Cagniard-
. LatouF, formerly Pupil at the Polytechnic School - 175

JV. Description of an Instrument for facilitating the Reductiori of Plans ; by
Mr. de la Chabeaussiere - r - - - • •• - - 179

y. On Mortars and Cements ; Experiments that show the Cohesion which
Lime contracts with Mineral, Vegetable, or Animal Substances ; extracted
from a Paper read to the French Institute the 17th of October, 1808, by
B. G. Sage - - - - . ... . - 181

VI. Observations on the Alkaline Metalloids ; by M. Bucholz r 183

VII. Farther Observations and Ii^xperiments op Oximuriatie Acid, by J. Mur-
ray, Lecturer on Chemistry, Edinburgh , - - 187

yill. Description of Firs, illustrated by Dissections. By Mrs. Agnes Ibbet-
son - - - - ■ - 203

IX. On the MotioivoHJie Flower of the Barberry. In a Lettei* from Mrs.
Agnes Ibbetson tV^^ - . - - . ..- 213

X. An improved Method of cultivating the Alpine Strawberry. By Thomas
Andrew Knight, Esq. F. R. ^., ^p. - - 214

' XL: On, the JSlature of ,Heat. By Marshall Hall, Esq. In a Letter from the
.. Author - - 213

XII. On some of the Combinations of Oximuriatic Gas and Oxigen, and on
tiie Chemical Relations of these Principles to inflammable Bodies. By
Humphry Daw, Esq. LL. D. Sec. U.S. Prof. C hem. R. L F. K. S. E,

222

Scientific News. - . - - - - 2J«

AUGUST,

C O N:iriE/K(T S. Tii

AUGUST, 1811.

EngraTingsof the following Subjects: 1. Diagrams illustrative Of the Motion
of Rockets, by W. Moore, Esq. 2. A new Thrashing Machine, invented,
by H. P. Lee, Esq. 3. A screw adjusting Plough, by Mr. Thomas Balls.
4. An improved Implement for extirpating Docks and Thistles, by Mr.
J. Baker. 5. A Pair of expanding Harrows, by Mr. Wm. Jeffery.

i. On the Motion of Rockets both in Nonresisting and Resisting Medians.
By W, Moore, Esq. - - - - - - - - 241

II. On the Defective Algorithm of Imaginary Quantities. In a Letter from a
Correspondent ----- -- - - 2i*

IIL On the Nature of Heat By Marshall Hall, Esq. In a Letter from the
Author - - - - - - - - - - V - 257

IV- On a Combination of Oximuriatic Gas and Qxigen Gas. l By Humpiiry
Davy, Esq. LL. D. Sec. R. S. Prof. Ciiem. R. L - - 260

V. Description of a new Thrasliing Machine, invented by H. P. Lee, Esq. <^

Maidenhead Thicket . - . ^ ~ - . . 274

VL Account of a Substitute for Hemp, prepared from Bean Stalks. By the "
Rev.Jamcs Hall, of Chesnut -Walk, Walthamstow - 27*

VII. A Chemical Analysis of Sodalite, a new Mineral from Greenland. By-
Thomas Thomson, M. D. F. R. S. E. Fellow of the Imperial Chimr^o-
Medical Academy of Petersburgh - - - 235

VIIL Account of a primitive Gypsum. By Mr. Daubuisson, Mine Engineer 292

IX. Farther Observations on the Fructification of the Firs. In a Letter from
Mrs. Agnes Itoetson - - - - - - - 295

X. Description of a Screw adjusting Plough, invented by Mr. Thomas Balls,
of Saxfingham, near Holt, Norfolk - - - 2j&*

XL An improved Implement for extirpating Docks and Thistles : by Mr. J.
Baker, of West Cober, near Yeovil, in Somersetshire - .,^ 3t)l

XII. Descriptionofa Pair of Expanding Harrows, applicable both for clean-
ing foul Land, and harrowing in Seeds. By Mr. William Jeffery, of ,Cotton
End, Northampton - - - - 502

XIII. Observations on an occasional Increase and Decrease of Bulk in the Hjut
of the Head. In a Letter from Thomas Forster, Esq. - - 503

XIV. On the Prevention of Damage by Lightning. In a Letter from Mr. B,
Cook - - - - . 505

XV. Extract of a Letter from Mr. Cordier, Mine Engineer, on Mount-
Mezia ----- _ 310

Scientiiic News - . - . . 312

SUPPLEMENT

fiii OTO*36r^E N T S.

SUPPLEMENT TO VOL. XXIX.

Engravings of the following Subjects: 1. Mr. Davis's Fire-escape. 2, Mr.
VV. Moult'ij FilteriivG: Apparatus. 3. Mr. B. Smith's Mctliod of relieving
a Horse, that has lallea in tiie Shafts of a loaded Cart. 4. Mr. J. Taylor's
Extractor of foul Air from Mines, &c.

L Method of assistiug the Escape of Persons, and the Removal of Property
from Houses Oil Fire : by Mr. John Davis, No. 7, John Street, Spitalfieids 321

IL New Method of applying the Filtering St04ie for purifying Water: by Mr.
William Moult, No. 37, Bedford Square - - - 324

nr. Method of raising a loaded Cart, when the Horse in the Shafts has fallen :
by Mr. Benjamin Smith, No. 11, Turnham place, Curtain road. Shore-
ditch .---.--- 326

IV. Method of Ventilating Mines, or Hospitals, by extracting the foul Air from
them : by Mr. John Taylor, of Holwell, near I'avistock - 330

V» On the Processes employed to cause Writing to disappear from Paper, to
detect the Writing that has been substituted, and to revive that which has been
made to disappear; Improvement of common Ink; a Notice (rf a new Ink,
that resists the Action of chemical Agents : by B. H. Tarry, M. D. 339

VL On the Senje of Smell in Fishes ;• by Mr. C. Dum^ri! - 344

Vir. On the Alum Mines of Aubin, in the Depaii:ment of the Aveyron : by
Mr. L. Cordier, Engineer in Chief, &c. - - . 352

Vni. The Croonian Lecture, on some Physiological Researches respecting the
Influence of the Brain on the Action of the Heart, and on the Generation of
animal Heat. By Mr. B. C. Brodie, F. R. S. - - - 359

FX. Notes by Mr. J. H. Hasaenfratz on the Disoxidation of Oxide of Iron by
Uidrogen Gas. - - - - - 370

X. Determination of the Quantity of Hidrogen and of Ammonia contained
in the Amalgam of Ammonia: by Messrs. Gay-Lussac and Thenard. 380

XT. On the Decomposition of some vegetable or animal Substances subjected to
the Action of H^at: by Mr. Gay-Lussac. - s 382

XII. Renjark on Mr. Moore*s Paper on the Motion of Rockets, In a Letter
from a Correspondent. - - - - 384

Index ---*.- 3&5

JOURNAL

OF

Natural philosophy, chemistry,

ANX>

THE ARTS,

t

MAY, 1811.

ARTICLfi I.

On the Interior of Plants, Letter II. J5y Mrs, AGNfiS
Ibbetson.

To Mr. NICHOLSON.
SIR,

JL Shall now give a r&gular history of buds, and their man-
ner of throwing, as it has been hinted to me, that the sketch
1 gave in iny last was not sufficiently explanatory and ample,
considering the importance of the subject to botany, its
novelty, and how little the real formation 6f the interior of
plants is understood. It is certain, that the diligence of
gardeners has far exceeded the labour of physiologists ia
this respect, and established first from accident, and thea
from practical experience, many rules, which should have
been suggested and taught by the philosophers of botany;
but 1 believe the Bcientific p«!lrt of this science seldom travels
as fust ad the practical, and that it is usually left for the
former to account for the reason why the process is good or
bad, after it has been thoroughly established. But this
may not always be the<:ase; when once we have a thorough
knowledge of th.? " interior formation of plants'*, the sci-
VoL. XXIX, N«. 13 1.— M4T, lill. M «fttiSc

4f^ ON THB iNTERrOK OF PLANTS.

entifvc may in its tarn precede, and enforce rules for gar-
dening.

There are three sorts of buds ; flower buds, leaf and

flower buds, and leaf buds oply. The leaf bud I shall pass

over for the present, as it differs so essentially ftom the rest,

while the other two are so closely approximated to each other,

ffnd the alteration so triflin°^, that I shall consider them as

. , one, and show at the end of this letter how they differ.

Putting therefore the former distinction out of the question,

we will establish atiother difference of buds, to make their

history the more intelligible; dividing them into four parts.

The difference 1^^» '^^^ buds of trees, shrubs, and some shrubs that are

of kttdsi perennial; which plants have the line of life running into

every part next the pith, and equally shooting; the bud ou

that line, whether in the middle stem, the branch, or the

twig; and forming the bud by a knot, as soon as the plant

has done seeding.

^Zdf The root buds, or those the buds of which reshoot
from the root each year, as in all annuals or herbaceouf
plants, where the stem dies down.

3d, Palmate buds, that is, buds of palms, grasses, arums,
&c<, which shoot their buds just before flowering, and give
therefore (preceding that time) no proof of possessing any
buds, having no principle or middle stem.

4th, The buds which grow in bulbous roots, which shoot
up when near the time of flowering, exactly like the last,
except that they have a stem,
l^ormation of '^^ return to the explanation of the first species; I
the buds of have mentioned, that in all trees and plants of this kind,
tiees, Ac. ^^^^ j-^^^ ^^ jip^ invariably follows one course in every part
of the plant; the difliculties buds have to encounter arc
therefore exactly proportioned to the situation in //hich
they are found, they Irave hardly any wood to pass ia
fresh twigs; in the shoots of the preceding years, they
have more; and in older branches still a larger propor-
tion of wood to travel tlirough ; but in the trunk of the
tree it becomes a very beautiful and amusing spectacle t»
behold the ease with which nature has arranged all for the
perfect accomplishment of her work. Trees and shrubs
"prefer shooting their buds just op^iosite the leaf, that it may
protefct and support it in itt eradle. In most treei the buds

be<£im

Oir TVS INTERIOR OP PLANT9& ^

b(*j»irt to shoot as soon as the seed is perfected ; it then forth*
« knot ou the line of life, breaking the two ends nearest the
wood, each of these ends generally becomes a separate bud,
and generates albumen all round it, while the old wood (aft
I have before shown) forms a vaulted passajre fur th€ budt
to travel on to their different cradles in the bark.

The bud itself consists of the knot ; a little albumen ; two
or three leaves, which may well be denominated cotyledons,
as they are literally what cotyledons are in the seed, un-
formed leaves, covering the new and tender shoot, themselves
distorted and hurt by confinement, and, if long retained bjr
bad weather in the bud, the seminal leaves will increase as
in the seed. Over these is a scale; and this is all I have
ever been able to find in the bud of a tree, or shrub, before
it arrives at its intended destination ; afterward it gets leavea
from the bark, and more scales from the rind to protect it
from the cold.

The second sort of bud is that found in herbaceous and i^ wrt pf bui»
annual plants, as all sorts of culinary vegetables, &c. Here
the line of life runs withm the pith, and is not so easily-
traced ; in many plants it crosses at every new shoot, and
stops the pith; in others, it meanders within the pith ia
different branches, running up.with each bud: but in all the
knot for the bud is formed within the boundary of the pith:
in some a number of buds follow in a string, in othersj little
bunches of buds shoot together. In the ranunculus^ poten-*
tilla, tormeniilla, &c., the contrivance is admirable; instead
of generating a quantity of albumen to each bud, a large
row of new wood is formed at the edge of the pith, in whieh
all the buds are inflated, and then they can hardly be said
to have any resting place or cradlet since they almost com-
plete their form as they are pushing on to the exterior, and
the wood being slight and made with divisions, which favour
the exit of the buds, which are but formed in the root, till
the growth of the branches transfers the line of life to a
higher points they then proceed from that part as in all
<Sther plants.

The third are the palmate buds. This tribe of plants, 3d sort tf bu^,
from having no stem, naturally adopts another mode of
growth ; but it is simple and admirably accords with the
^ B !3 other*.

•theri. The whole plant is formed of leaves, till floweHnj^
time, except the root, (which in every respect agrees with
•ther plants, having^ the same divisions between the root
and leaves, as I discovered between that toot and stem in
•ther piantSj and whi^h I called the grand obstruction) : but
when the time arrives for the plants to become prolific, there
runs np from the root a slender thread, at first like pack-
thread, within the axil of the leaf, and under the cuticle.
This by degrees increases. It is composed of many little par-
cels of the germe of buds, in each of which is the knot of the
line of life. As they rise, they enlarge, till, too much swelled
fttr confinement, they burst forth into flowers; appearing to
grow from the leaf: but they have in reality no connexion
with it, except that of borrowing from it the spiral and nou-
rishing vessels, which run into the corolla. I have traced the
palm when just going to flower : for though frbin the want of
air in the hothouse, it had never flowered, yet the buds were

* within. 1 found more in the root just ready to run up, and

9ome halfway; it is exactly made like the grasses, and like
the arums, and every plant of that kind which has no stem ;
but in palms it is impossible to know all this without dissect-
ing one. This order of plants flowers in various ways, but
generally, at the top of the plant. The grasses carry up
their diminutive buds through the flower stalk, one by one,
with the Ihie of life. In the arums it is very easy to trace
the buds, but they increase more and in a quicker manner
than in most of this class.

4tb sort of bud. My fourth sort of bud is confined within a bulbous root*
This explains itself; it begins at the root, and completes its
form, more than is usual in any other plants except those of
the ranunculus tribe. Before it leaves the root all its parts
'4Lre generally designed; they only enlarge, and the peduncle
grows and raises them to view, having the bud at the top,
hence the histories of the flowers to be found within the
bulb. There are many however, that by no means resemble
what they are to be, any more than many germes,when first
concealed in the bud; because the parts are yet seldons
proportioned to each other. The tulip and hyacinth are
peculiarly perfect in the bulb.

1 have now given a simple account, sufficient to make al]

understand

©1? THE INTERTQR OP PLANTS* J|

wnderstand the nature and progress of buds in^ll pUintg/
except the cryptojj^amia and water-pUnts. These I am deeply
studying; and I flatter myself it will not be long before I
shall be able to complete ray sketch in this respect. — I sball New practlcei
now endeavour to account for the cause of the succeeding ^^ gardening,
of various means lately adopted in gardening, and show the
reason that success attends such practices. All that For- Why For-
syth did to old trees, was to take from them the rotten ^J^^^*^'^'^^^'^®*
part, which wholly checked the growth of the albumen,
by soaking vip the juices, which should have produced it ;
but the sap once returned to its usual office, forming the
»ew wood, or albumen, gave an increased vigour to the lir^e
of life, which, when the rotten pi^rt w^s cut away, had room
to shoot afresh, and by a quicker circulation of the sap re-
newed the vigour of every part of the plant. Scarcely haa
the year power to run its ususal circle, before a tree so reani*
mated will begin to shoot at the yery heart; the little pith ,^

to be found in so old a tree can hardly raise moisture
enough for the innumerable buds, which form in every part,
onthe line of life; beginning at the dilapidated part, and sooQ
communicating to all the rest. It is astonishing what good may
be done, by thus now and then paring away a part, that ap-f
pears to be beginning to decay : but then it must be cut with
great c^re. And covered with the plaster ordered by Forsyth,
which is excellent ; and not left to contract the rot. The The presert;!'
dried stump of a tree, or the remains of a broken limb, tive to th*
may in a very few years (by this management) be the source
©f new shoots, more than equal to those before lost; and
though I believe with that philosophic observer Mr. Knight,
that there is a term of life and vigour, beyond which a tree
cannot pass : yet it is certain, that it is a very ancient time,
»nd that almost all our trees die from careless inattention,
«nd probably at half their proper age.

There is a strange idea universally spread among physio* Sap ina trte
logists, arising (I must think) from our ignorance of the in* "*'^"' ■**K''
terior formation of plants, but universally received as a
truth; that as wood grows old, it contracts in form, till all
the passages of the fluids are stopped, and it remains ina
kind of torpid state, till it dies. This idea appears to me
Id be so contradicted by all | have seen in nature, by mv

^9UFljr

• - •N THE. INTKRIOE Or FLlKTi.

hourly itudy of the disorders in plants, and by th» consider*
a^ion of that sort of life which plants possess, that I am
very anxious to show the fallacy of it. Wood once reduced
r ' - to thib*tate (it stands to reason) could never aj^ain recover;
i^ could never throw out buds, it could never again be re-
stored to a regular rising oi the gap; for the vessels are so
•mail, that, once choked, it would require a miracle indeed
to 0{>en them ; and yet it is well known, that a tree may
be restored to almost pristine vigour, by a little cutting and
care: and then, so far from being in a fixed sstate, every ves-
sel of the wood must be moved out ot its phice, must bend
in one way or other for the exit oi the buds, the juices must
be so plentiful (the sap in pHrticular) as to form albumen to
engender and accompany all those buds. Where then i^ its
Parts between torpidity ? It is true, that, the older wood grows, the more

t^« Tcssels j^ jg compressed ; but it is the middle part between the ves-
compre8s«d by , , V . , . . , ^ , . «

health. sels, that is reduced. A very simple proof may be giren of

this, by cutting the oldest piece of wood, that can be found
in a liviisgtree, and placing it in the fire: the quantity of
sap, which runs frona each separate vessel, bubbling and
spouting out a* soon as the heat acts, will quickly show
how full of sap the oldest vessels are. But this very com-
pression only more strongly proves the health and strength
of the tree; it quickens the circulation of the juices by

#-, pressing the bastard pipes agajnsj ihe sap vessels, and thus

gives increased vigour i<) the tree. I will be bound to say,
that the passagjP of the vessels was qt^ver suspended in a plant,
without causing the gangrene directly, apd very soor>
death*. To prove, that 1 am not too hasty in this assertion,
I will simply show the general manner of thp death of trees,

peathofa when they die natupally, and without accident. The first
appearance of sickness is the hanging down of the hranche%
and leaves: this is followed by a sweetness pervad ng all the
different juices of the plant, attracting everv species of insect,
-which soon cover and spoil the leaves with their filth: then
littlediv'sonnof the wood (orrown weaker than the rest) burst
their vessels, and begin a sor^ of rot, which increases dai'yt
fhespiral^wires, which attach the leaves to the stem, begin

tree.

^w

•This is so peculiarly the case, that almost all the disorders of trees'
se from a stoppage of the circulation in different parts. *

ON TH« INTF.ftlOR OF PtANTi. f

t<9;fijrew brittle, and their cases to crack: the nourishing ves* •
wels round them decay, and the first wind> of course, takes
off the leaves, and the next circuixistanee is g-enerally the
death of the line of hfe; which, when once it begins to be
affected, soon hiirsts, turns black and dies: this spreads an
increased sweetness over the plant, by the juices of the line;
wjiich^ thoui^ii often bitter, are luscious, and tempt the
Hffi^m., From this time nothiug can save the tree, though
the bark and rind may still show soijie green; nay, 1 have
known a ftne day burst the leuf-buds, so little has the leaf to
do with the plant, but they are soou gone; and the remain'*
d^r sinks to torpidity and death, I have watched many "^ ?

trees from the first to the last in this way, and -taken down \

their symptoms as they increased, by cutting branches, and J

thus judging of the progress of the evil; but if at the first
appearance of it, care h^d been taken, the tree had been dug
round, and a little dressing thrown with frpsh earth; and if
the disorder pontinijed, jind showed in any particular spot;
bad this been cut away, ajid managed as mentioned above
for to excite to fresh action is every thing in a plant, and air To excite to
and light if possible let to it by cutting down any rubbish that h^JaUh^o a*
impeded it, njany trees might be saved, and much wood r&- plme.
illoredto the country. Light is certainly the most necessary
desideratum to pliints. It is painful to see how trees will
twist their branches kn search of it, and perhnps be disap-
pointed at last. A tree is therefore so far froqi dying by
too much compression, that this is always a sign of health ;
^s the spreading out and growing irregular in the branches
is a sign of sickness. !But I must dwell on this subject no
lopirer, ,1

I mentioned, that when a bud is protruded, a knot is The breaking*
fbrmed on the line of life, which is broken, and the two ends of me line of
form bqds. AH that is necessary therefore to form a bud is, ^ *'
to divide the line of Wftt ; this gardeners have learned to do,
by cutting a gash in the place they mean to make prolific,
Xhey th^n not only divide the line, but they also separate
^he wood, which hastens the bud, as it has not to prepare the
>vood for its exit from the plant. This very much quick^r-ns
the business ; but then there is evident danger in the doing
^t. In the first place many buds may be destroyed in theij^

% aijr TEE XNWRXOB OF Pt4IfT9.

wty: the finger should therefore be pressed all up the part*

formtbuds. *** ^^ ^^'' assured that there is no branch on the point of

shootina:; the bud will be felt us soon as the bark and find

have made a socket or bed for its reception, which is don#>

before the bud is half way on its journey: then a plaster

fshould be prepared to cover the gush, without pressing it

too close, but taking care to guard it well from the air, lest

any should get in and cause a rot, more easily gained than

cured. I have often (bund a bit of bladder, placed under

the plaster, a better preservative than any thing el^e, if per-

fe6^1y clean, and free from all grease.

Difference of j promised at the conclusion of this letter to show the

the flower bud ,.->, „ , _

and mixed difference ot the flower bud, and the leaf and flower bud,

bud. wh'ch is very trifling. They both come from the same

place— the line of life — and both in the same manner. In
the mixed bud, when arrived at its cradle, the rudiment of
the flower stops while the leaf is weaving. The first has
a:1so some few leaves to complete, and many scales. The
fcinale or pistil of both was a rude mass containing the
seeds, but nc»w begins to take its proper form; while the
xnales, all joined together, and proceeding from the wood,''
are completely fashioned. The scales in the mean time are'
growing to coyer it thoroughly, and roost buds have a quan-
tity of their juices (that is the blood of the plant) lying be-
tween the several covers as a sort of resin, to ^^rptect it fron^
the air and cold, of which it is now very susceptible. In the
mixed bud, the leaves always are finished ?jt the top, before
the flower, even where the flower comes out first, to prevent

Various juic'i the matter of the leaf, or mixing with the juices of theflower;

"f *^^ t^^ ^ ^^^^ ^^ ^^ ^® peculiarly evinced throughout the whole for-

Mparat*. mation of plants; and which it is wonderful to me physio-

logists have not observed, since their whole make is founded
on this principle— the keeping all their juices perfectly se-
parate. For this reason alt the vegetable world is formed
cylinder within cylinder; and, when there are holes, they
are so contrived, that nothing but air can enter them. I
shall soon exemplify this by delineations of the passage
between the stem and the peduncle; which plainly showr
how strongly this principle is maintained in every instance,
and hjow little therefore we can judge of the effect of th^

juices

jmces'^when we mix them all together. As to the! leaf bud,

I have in my last letter said, it is begun and finished in the

bark* It is indeed a history in itaeU", and one ojf the most

wonderful I know. There is so much pressinj^, rolhno:,an<l

weav-ng;, that | have constantly viewea it with fresh astonish*

roent; tor after being woven with all its parts loose and Formatiortu of

open, and all the ends hanging to it, like a piece of cloth ^*^e 1^*^ *>ud.

fresh from the loom, it is folded anew, rolled in a particular

manner, and laid in a liquid; then unrolled, and again

folded in another manner, and pressed in the bud; and this

19 repeated several times, till by degrees losing alf its ends, it

is prepared i'or making the edges, which is the most curious

part of all. I have already detailed this in my first letter,

and shall not therefore repeat it, but only say, that the leaf

buds of those plants, which have no stem, are formed within

the bosom of the othe^ leaves, joined to one end of the cu- ' ,

ti( le, not in the root. 1 have much to say on this subject,

bot it must be in another letter, and one which is restrained

to leaves alone.

I must now say a f?w words on a subject I have long de- WhetTicrthMe
ferred touching upon, but which I have i.ot the less studied ; ^^slg^s7o"r^"he
indeed I hardly know one that has lately engrossed so much sap or not?
of my thoughts; 1 mean, *' whether there is, pr is not, nrir^
culation of sap through plants." After tht'most mature in-
quiry, the most exact resebrch, 1 cannot dife<*over the slightest
reason for believing, that it taVes place even in trees; on the
contrary, the most potent arguments, drawn from the very
nature of the vegetable tribe, militate against it. That there
IB a regular passage upwards for the rise of thesap, no one de-
pies; but returning vt-ssels from the head of the plant to the
Toot 1 must think a fallacy; arising from that unfortunate
comparison established between the animal and vegetable
world, which was well enough in the first birth (jf both, but
has been carried in my opinion to a false and blatnable ex-
tent. Can any thing be more unlike Hnimal' life, than the
shooting of the buds? Thife will, I think, mbtfe plainly ap-
pear, in drnwing a comparison betweeii the functions of both
— in an animal constant motion is neressnry to circulate the Sap too much

blood; its juices, formed in the body itself, from the dif- ^'^^^"'^"^ ?^

•^ , r 1 • ^^^ various, for-

ferent secretions I believe, (bqt I do not understand ana- tnation*.

tomy,)

JO #y,THE mTBRlM OF PLANTS

toroy,) and constantly added to by food as solid as the ^esk
it creates, and a& the blood it; j loducfs. There is no yearly
extension of body, except a trifling in(:rease at first, that
could require the absorption of such a fund of matter as tl)C
whole blood of the animal to produce it : but in a tree each
year creates almost a fifth qf jthe weight^.upless tj?B tree is
very large, in fruit, flowers, leaves, fresh branches, new rar
dicles, and seeds. Whence then could the returning jiiices
flow, exhausted as they must be? 1 haye weighed the yearly
increase in a small tree, and it far exceeded this calculation.
Besides in an animal the blood is form d in it, whereas in a
tree the sap is the juices of the earth. Nature would not
therefore draw up more than is necessary for its various pro-
ductione, merely to carry it down again. In animals the circu-
lation, increased by exercise, occasions a constant dissipatio,ii
of the several parts, which enter into its composition, and i^
therefore, I understand, productive of a thousand goodcons^f
quences, without which the animal might become torpidapd
insensible, from the efle^ls produced on the brair) ; but in ^
tree I see no end it can answer; nor cpuld I ever find any re-
turning vepsels that would carry coloured juices the contrary
way, though I have sought them in every part of the pl^nt,
As to the reason given, " that, if a deep piece of wood was
cut o^t,of a tree, a large portion of matter grew in the upper
- . part of the woupd, and none in tjie lower," it is easily to he

ficcounted for. The momenta tree grows unhealthy, it gets
full of these bunches; but such a cut must at once produce
them. The ficst efifect of such a dilapidation is tq arrest thp
vigorous flow' of the sap: much of this is therefore stopped^
and often breaks some of the wood vessels: this forms little
pools, which occasion the rot, while the other vessels, filled
>vith air, are inflated and increased: in the mean time the
line of life, which has been divided by the deep cut, shoots
put many new germes, and forms new wood to engender
jlhem ; and when you take off the lump so made, it is a mass
of loose wood, of rotten albumen, find new shoots half alive,
jmd half dead ; while the under part, losing its sap by ble^d-
jng, which the other could not do, as the vessels could not
discharge themselres backwards, ip only dried up; and the
{>W(}s, opt being able to form for want of the «ap, decay in the^r

ftrst

ON THE INTERIOR OF PI A NTS. H

first shooting, and of course the lower pftft of the wound i's
not at all incrensed in size. This appears to me perfectly
the truth, I have dissected many pieces jjrown in this way, »

and they have at ways proved such as 1 have described abore;
it is therefore a proof which militates against the return of
the sap vessels, rather than for it. The manner of the forming
of the bud is also much against it, and I know not a sin-
g-le reason for it. Perfectly to understand the formation
of the ju.ces and to be able to separate their differ-
ent parts and analyze them as they should be, is at present
my roost anxious wish. There are in all plahts four different Your different
torts of juices, which should with the greatest care be 4ept sorts ofjuic«
asunder; I have some curious details in this respect, though '"^ P'*"'**
scarcely yet worth\ to belaid before the public; but I hope
my next experiments will be more exact, however I pro-
cured some ve»-y curious crystals of a peculiar shape, by
means of subjecting the juices of the line of life to a very
strong heat, and afterwards cooling it very gently ; but I
hope to procure bettfer information; for 1 am but an indif-
ferent chemist, though often dabbling in the science.

Though 1 have not in my last two letters taken notice of
the foundation on which my studies rest, that for which I
principally undertook to give the dissection of the interior
of plants, that which appears to me to be the fundamental
and systematic part gf bptany, "the natural affinity of plants

to each other," yet 1 have not forgotten it. 1 continue to N**""'«fl«-

. , , . . ■ n>tj of pUntt,

pursue it with the most exact care, noticmg with attention

each copnejiion; and strong lines indeed does the formation

of buds draw between plant and plant, as 1 shall soon show;

^iicpuraging my hopes of finding something like a plafl, on

which a system may be discovered, without expanding into

rules too dirfuse to serve such a purpose. That the great-

^t, t\)e pfiost scientific l^otaoist will e_v€r,^?e able to make

one generally useful, and to supercede all artificial methods,

I much doubt, when such a master as Jnssicu has failed,

tutthutone of morehumb'e pretensions may be found ; 1 am

ftill most sanguine in ray hopes, since the more I disftfti

the more proofs of that system 1 find in nature.

I am. Sir, your obliged humble servant,

AGNES IBBEISON.

- * JExplanoHon,

w

'^t^TH CHEMICAL ArriNlTY-

Explanation of the Plate,

, Plate I, fig. 1, A horizontal cutting of the re<^ cabbage; t#
show the difference between the leaf bud and flower bud in
annuals: the flower bud proceeding from the line of life,
flowing within the pith, asatctf; thf le^f bud generated
within the rest of the leaves, as at bb h»

Fig. 2, The interior of the leaf bud, where many flowery
grow in a bunch ; the scales taken off. cee new flower buds
just generated on the line of life.

Fig. 3, A leaf bud, where no line of life is to be found.

Fig. 4, Mixed bud, of the apricot, in which the flowei*
is completely separated frona the leaf. <f, the female ; e^
males ; f, the line of life.

- Fig. 5, The manner in which the leaf buds grow in the
palmate buds. Each spiral turn makes a separate bud.

Fig. 6, A cutting of the potentilla; showing the circular
line of albumen, in which the buds are formed. I have-
sioce found a vast number of annuals fprmed in this man<^*
ncr; that is, having the circular line of albumen within th^
]i»eof the pith, in which the buds are very much formed.
' Fig. 7, A sort of screws formed at the end of many new
shoots, which are cradles for buds.

Observations on the Hypothesis, which refers chemical Affi,-.
idty to the electrical Energies of the Particles of Matter^
By J. D. Maycock, Msq» Communicated by the Aur
thor*.

Mr. DaTy's 5'ccf. I. J? ROM the consideration of an important, anij
kjpothesis of interesting series of phenonienaf, Mr. Davy has throwij^

* TBts Essay, in very nearly its present form, -was read to the Royal
Medical Society of Edinburgh, on the 13th of March, in answer to a
4|utstion proposed by the Society, and gained the gold medal. Th«t

question

• t Phd- Trans. 1807 : or Journ. vol. XVIII, p. 321, XjX, p. 37.

ON bilEMECAL AFFINITY., |J

liut a conjecture, that chemical affinity and electrical at- ch«mical affi-
traction are identical forces ; and haa very ingeniously en- "^^y*
deavoured to point out the general application of the prin-
ciple. This hypothesis, proposed by its author in the form
of a question, has been too hastily admitted by some as
an established doctrine; and speculations have been founded
On it, which lead to the most extensive and unexpect^
conclusions.

The precipitate adoption of this hypothesis seems to have Electrical stat^

arisen principally from the imperfect and confused notions ^^^ electiical

, •,• • I • , I energy the

commonly prevailing m respect to electrical phenomena, same.

I therefore deem it necessary^ before proceeding to discuss
the question proposed by Mr* Davy^ to state such of the
principal phenomena of electricity, as may unequivocally
define in what sense we are to understand the terms electri-
cal state, and electrical energy— terms which will often oc-
cur in the following pages; and which are t6 be festeemed
aynonimous ; both being employed to denote a certain state
•f existence of bodies, in which peculiar phenomena ar^
tvinced.

Bodies are said to be in different electrical statfcs, or to £)ifferent an<i _
have dissimilar electrical energies, wken they attract each ^*^"*'^**^^*^v
•ther: their electrical states or energies are said to be si* *

milar, when they repel each other. But we are to keep in
mind, that these electrical attractions and repulsions arfej in
their effects, distinct from the attractions and repulsions,
which bodies ordinarily evince. Two cork balls, suspended Actions pro-
by silk lines, will indicate attraction or repulsion, accord- ^"^^'^ ^^ '^**'"
ingly as they may be sn different or siniilar electrical states;
and in either case, the motions arising in the balls will be
in direct opposition to such as take place in consequence
<if the law of gravitation : — they will be diametrically con*
trary to those which appear in the action of the pendu-
lum.

i

Question was : " Whether are the phenoriiena produced in the deconi-
position of bodies by galvanism capable of bein^' explained on the usual
principles of chemical atlraciion; or do they seem to establish the
theory, that chemical phenomena depend entirely on thf electrical ener-
gies ©f the parlicl«s of matter ?'* •■ .'.f

Whe»

14 Olft CHEMICAL AFFIN!Tr»

Whew bodies are attracted, in consequence of a differerte#».
in their electrical states, and come into contact, or within a
certain degree of proximity, each of them acquires a nev*'
tlectrical state, and the new electrical states are found to
he similar: for between the bodies there is now exerted a
repellent force. The operation, by which difference of
electrical state is destroyed, is very frequently attended by
the emission of light, a crackling noise, a peculiar smell,
&c. The property, by which a body is broiit^ht to the
same electrical state as that of surrounding bodies, is termed
the condi'Cting power, and is very various in different sub-
stances. Metals have the greatest, sealing wax and glass
the least conducting force.
Vary in their Bodies may, on account of their electrical states, attract
*»€•• or repel each other with various degrees of force ; we there-

fore conclude, that various degrees of difference in the
electrical states of attracting bodies exist; and that the
electrical fitates of repellent bodies vary in different degrcep.
fronri the electrical state of surrounding: bodies, >

The game ope- When two dissimilar bodies are subjected to the san»«
ration produces operation, the electrical state produced in the one is more
uic^aTSects!' ^** ^^^* different from that excited in the other The same
operation, indeed, not unfrequently appears to be the cause
of diametrically opposite effects, when applied to dissimilar
bodies. If a glass rod, and a rod of sealing wax, be excited
by friction, and their electrical btates be communicated to
two insulated balls, which may be represented by the signf
A and B: both these balls will exert an attractive force on
the surrounding bodies; but A will more powerfully attract
those bodies, which have been in contact with B ; and vice
versa B those, which have been in contact with A, than
those which remain in their natural state. From this fact
vie learn, that the sealing wax and the glass differ less froiW
surrounding bodies, in their electrical states, than tliey do,
in this respect, from one another ; and consequently, that
the friction had produced opposite effects on them. Iif
?I«»andn3inu« the theory of Dr. Franklin, an electric fluid is supposed
•lectricity. ^^ ^^ accumulated in the glass, and dissipated in the seal-
ing wax. Admitting the existence of an electric fluid, it
trottld seem to follow, that, if it be accumulated in the

glass*

«K CtfSMfCAt AFFINITY. \S

5r ^.

glass, it must be dissipated in the sealing wax : but as far

as my knowledge goes, it has never been determined, that
it is in the glass, and not in the sealing wax, that the accu-
mulation takes place. 1 mention so much of the theory of
Dr. Franklin, not with an intention of entering into a de-
fence or refutation of its principles, but rather to point out
the origin of the terms positive and negative, plus and
minus, as applied to the electrical states of bodies. I con-
tinue to employ these expressions, as it would be difficult
at present to inveat others freer than they are from hypo-
ihesis. ^

It is important to remark, that the phenomena, which a body, to

have been enumerated, do not occur in every electrified ^^'°^ ''S"' of
, J m, p , • • 1 • 1 • • • ,1 electncity,

body. 1 hat signs ot electricity be evinced, it is essentially should be near

requisite, that the electrified body be in a state of proximity »»other in a
with other bodies electritied in a different manner. — 1 insu-
lated one of Beunet's electrometers*, and, by a bent wire,
connected the foot and the plate of the instrument. When
1 electrified this wire, a momentary and extremely trifling
effect was produced on the gold leaves; but they returned
to their natural position, although the whole apparatus was
kept by one experiment in a state highly positive, by ano-
ther in a state highly negative. The repulsion, when duly
established, appeared to be equal between the gold leaves,
and between the gold leaves and the tin foil. Had either
the gold leaves or the tin foil been alone electrified, the
effect, as is well known, would have been a separation of
the gold leaves. Fr«;n this experiment it also appears, that
<fUr Earth may possibly be very highly positive, or very
highly negative, in relation to any other of the planets,
without our instruments indicating such state; our Eartli
bearing the same relation to the bodies of the universe, that
an insulated electrometer does to the various other bodies
of our Earth. That the various bodies of our Earth do The various
naturally possess the quality we denominate electrical, is bodies ©f cur

. • .. 1 I I t !• 1 • I Earth naturallf

an opinion, not only probable trom many general consider- p^g^^^, decui

ations, but one vvhic:h admits of proof from the following ^^ty.

~ *
* I use the eI«ctromet«r improTed by Mr. Cuthbertsoa,' but' without ."ij^'j-* 1**^!-
the condtwi»er, • •* ^ "' " ' ' * "^

statemeot

«

ON CSCMtCAL AFFINITY.

Statement of fact. If two metallic balls, A and B, be
placed near to eath other, and to a small cork ball, sus^
pended by silk, and positively or nei^atively electrified,
-which may be called C ; and if A be connected with the
Earth, and B be positively or negatively electrified in a
greater degree than Ci A and B will both attract C: but
A will attract C w'lth greater fprcfe after it has been in con-
tact witii B, than before; and the contact of C with A wilt
augment the attraction between C and B. The eflrect is
precisely the same as would have arisen, had A and B been
both insulated, and differently electrified, and C connected
with the^ Earth.
Circumstances It is also to be remarked, that, although two bodies, ia

xnay pteirent j^iffej-eat electrical states, be near td each other, it is very
the appearance >,^;. ; .' .... ^

•fattractwn. possible, that they may not mdicate attraction. If, fof

instance, two fixed and insulated metallic bklls be electri-
fied, the one positively, the other negatively, and a email
\y\t of cork, suspended by eilk, be brought between them,
the attraction of the cork for one metallic ball may be juJ^
sufficient to counteracl its attraction for the other.

The preceding observations are Unconnected with any
Jiypothesis concerning the remote caUse of electrical phe-
nomena; and aie, iiideed, nbthing more than a general
Statement of facts, established by experiment. Electricity
is therefore a science, which his for its object phenomena
produced in consequetifce of a difference in the electncal
state of bodies, so situate, as to be within the sphere of
action of each other ; among which phenomena are certain
modifications of the attractive and repulsiVe forces, that
bodies ordinarily evince. £lectrical state, or electncal
energy, is the (Quality, to which such phenomena are re-
ferred. These conclusions are obv ously deduced fiom the
X artificial electrical states; but, if they do not equally apply

to tlie natural electrical states of bodies, I confess I have
no idea of what is meant by this expression.
^itdifferencto ^^^^' ^^' ^^^^ *^ Consideration of electrical phenomena
of electrical jn general, but more part cularly of those which occur
r^^^-wiih^he- during decomposition by galvanism, Mr. Davy thinks it
meal affinity probable, that difference of electrical state is identical
te<iui{ei pro«f. ^-^^ chemical affinity, and an essential property ©f mat-
ter.

on CBEMICXL APPIMITT.' |7

ter*. ■ Tbe irnportaot effect* that »uch a pnncipl<», if

adopted, would have on our chemical and physical reasoning,

<;crtaialy require, that it ahould be established by the most -s

•tttisfactory evidence. How far it is ho will appear from the •

following ob<erfation» and experiment*. ^

Gravitation and cheuiictl union are operations apparently Connexion wf
dlssimiluri and it is by no means surprising, that ^hey ^^-^jj^'l^^^j]^^'*
should have been, for a considerable time, referred to the tion,
agency of diiferent powert. At present we cannot but per-
ceive, that gravitation is intimately connected with chemi-*
cal action, by the various intermediate effects of the at- *
traction of cohesion, of capillary attraction, and of hygro-
Bietiic affinity. It has never, indeed, been demonstrated,
that clieinieiil affinity it identical with the attraction of gra-
svitation; nor do I consider the opinion as admitting of such
proof. Philosophy has in this instance done enough, and
perhaps its utmost, in removing all objections to a general
doctrine, which is reoommended by strong and insuperable
analogies. Now those who admit, that gravitation and che-
Hiicat aOiiiity depend on the same principle, cannot for a
moment maintain, that chemical attraction and electrical which Is not

attraction are identical : for it can be demoostratcd, that tlte ^^"^ ^^"^^ ^"^

electrical air

attraction of gravitation is not identical with electrical at» tiactiun,

tractioB.

In the first place, if gravitation depend on difference of for bodies in

electrical state, there must be some body at the centre of **'.^^f^"\*^^^
. . t n cal states d»

the Earth having an electncol state different from that of not gravitate

every body at the surface, since every body at the surface tl»ff«^f*^'«ly ^»

. II o li • 1- thecentrei

tt apparently attracted to the centre, nut as all bodies at

the surface are su{)posed to have different electrical states,
in respect to one another, there cannot exist the same dt^
gree of difference between tlie electrical state of any two
diititimilar bodies, and that of the body at the centre, and
consequently dissimilar bodies should be attracted to the
ceutre with unequal d«*gree« of force : a conclusion per-
fectly inconsistent with ihe principle* established by Sir
Isaac Newtocf^s beautiful experiments with th« pendu-

» PbiUs. Tran^ 1807, p 29: at Jjur. toI. XIX, p. 50.
V«i.. XXIX-.May» Uil. g lum,

lum*, and on wiiich is founded the wholfe »y8tem of nataml
philasophy.
»nd «]ectrical In the second place th«l force of electrical attraction is,
attraction is catetis paributy jJroportionate to the extent of the surfaces
the surface, of the attracting bodies; gravitation, on the contrary, 10
f^uatwm 10 proportionate to the quantity of matter reciprocally at-
tracting, and has no dependance on the extent of surface.
This essential difference between the two powers is pecu-
liarly stijikin^'— A bit of gold leaf, of tin foil, or of sheet
lead, will acquire a rapid motion through the air, when
acted ion by ah excited electric, which would not sensibly
affect an e^ual qu:uitity of either of these metals in a
globular form ; and yfet the gold leaf, the tin foil, or the
sheet lea4 trill have to ov«»cotne considerably tnorc resist-
ance In passing through the air, than will a globule of gold,
of till, or of lead. On the contrary a given quantity of
gold, of tin, or of lead, will gravitate more rapidly, in the
tnediura of our atmosphere, when in a globular form,
than when beaten out into gold leaf, tin foil, or sheet lead ;
not that the force of attraction is diminished by the exten-
sion of the metals, but because in an extended form they
hivt to overcome a greater degree of resistance from the
clastic medium, through which they are to pass. ..

Thus, I conceive, it is demonstratively proved, thitt the
attraction c^f gravitation is not identical with electrical at-
tKaction. Qur views, therefore, of the phenomena of na^
ture would not be reiwlered more simple by admitting, th^t
* chemical attraction and electrical attraction are identical ;

tA this woukl draw a line of distinction between the prin-
ciple of chemical attraction, and the principle of gravita-
tion. Every one must determine for himself whether the
hypothesis, proposed by Mr. Davy, be supported by argu-
ments more plausible, than those, which can be adduced in
favour of the identity of chemical attraction, and the attrac-
tion of gravitation.
Attraction Pliilosophei's of the present day most commonly speak of

«o«*idered as attraction as an ultimate property of matter ; not that they

• Newlont PhJi. Miat» Frlocip* Math. L. Ill, Prop. VI, Theor. VI.

y0 ■ conceive

09 CHEMICAL AFFINITY., « l£|||

tonceirc it to be really so, bat that they are unwilling to an ultimate
add to the many vain speculations, which have bejBiji pro- ^^^{ter.
posed to account for it. What indeed has been denomi-
nated electrical attraction, of which Mr, Davy consjidera
chemical affinity to be a modification, is yet very generally
referred to the agency of a subtile, and essentially fluid
bbdy. Repulsion is almost universally attribntcd to th^
action of such fluids. It is however to be remarked, that
we have no direct evidence of the existence of these fluids,
aa they have never been the objects of sense. They are
agents erected entirely by human ingenuity, for the purpose
of explaining phenomena, which in the pride of speculation
vre are ilnwilling to admit are inexplicable. The whole of
the modern doctrines, respecting light, caloric, and the
electric fluid, are hypothetical, and allow only of such indi*
rect evidence, as is derived from their capability of explain-
ing the chiss of phenomena, on account of which they were
assumed. That they do so to a certain extent cannot be
questioned. It must, however, be admitted by every one
who patiently investigates the subject, that there are pheno-
mena, connected with the temperature and electrical state
of bodies, which cannot satisfactorily be accounted for on
the generally received opinions : and although there is, at pre-
sent, no positive objection to the supposition, that light is
tl material substance; such may possibly arise in the pro*
gress of discovery. The hypothesis, therefore, which refe'rs
repulsion, or any modification of attraction, to subtile fluids,
although it need not altogether be rejected, should be re-
ceived with caution, and never made the basis of our general ,
principles.

In the present state of our knowledge, it would, perhaps. Attraction and
be most prudent to abstain from all speculations, concerning repuL'ion,
the cause of attraction and repulsion, and to consider them
both as properties of matter, prevailing under different cir-
cumstances. It is at least certain, that we have as unques-
tionable ^perrence of the partides of ponderable matter
repelling, as of their attracting each other. Now it can- Modified by
not be doubted, that attraction and repulsion are very much causes affect-
modified and affected, among other causes, by those which
modify Jk6d aifect tl>e electrical iiat< of bcdi«s. Indeed
C 2 bUtth

^P •V CHlMtCAL IFffNlTY.

8U(?h mifttlificatlons of attraction and repulsion are am«ns^

the tnostobvioiw pbenoinena of electricity, and thn!«e t))nt

first p:ave,ori<i;in to this science. But after what has been

said, it must appear impossibl»i to consider difference of

electrical state a» identical with the principle of attraction.

Neither do I think it could be seriously contended, that

ficnilarity of eU'ctrical state is identical with the principle of

repulsion; as this would, at least, involve the opinion, that

similarity of electrical state, whether positive, or negative,

is identical with the canse of increased temperature; au

opinion I, by no uieims, feel ujyself called upon to confute.

Supposition of Possibly, however, it was never meant, that difference of

minute d I fftr. electrical state is identical with the principle of chemical
enctj in the . . . . .

elettrica! »tate ^f "^*-'tion ; but tliat there exist m:nute djfterences m the

of dissimilar electrical states of the particles of dissimilar kinds of mat-
' ^ ' ter,-— that ^nch differences are not destroyed by contact, —

and .that, althougli they are not sufficient sensibly to af-
fect tbe vibrations of the pendulurw. they rnay yet so mo-
dify the principle of attraction, as to give rise to the pheno-
mena which favour the idea of elective affinity. This is
certainly the least objectionable form tht- hypothesis can
assume. The supposition, however, that dissimilar bodies
preserve different electrical states, i» in opposition to ana-
logy ; since we invariably [)erceive a tendency in bodies to
acquire similar electrical btates, as far, at least, as our most
cteiicate instrumeUtti inform iis; and as this law holds t9
e»ery measurable difference, it would surely be unphiloso-
phical not to consider it as absolute, and without exception,
P.irtiel«j miRhi Were we to adopt the th»*ory of Dr. Franklin, it mij^ht
hiATe different appear t^ follow from many facts, tlmt dissimilar bodiea
eteclridty* ^**ve different capacities for the electric fluid ; but tlvis
would surely atford no stronger argument in favour of the
pt>inion, that bodies exist in different electrical states, than
might be drawn from their having different capacities for
caloric, in nupport of au opinion, that they have naturally
different temperatures. The hypothesis proposed by Mr.
Davy cannot, therefore, be admitted,' until it shall have
been proved, that it is capable of explaining, in the most
satisfactory manner, the phenomena on accotint of which it
wan astumed; and that these phenoD.ena are inex) Liable oa

any

^llCllEtorCAt AFFINITY. f/ft

any known, nncl ]*»ss exceptionable principle. I shall en»
deavoiir to determine how far Mr. Duy\ 's proposition briiij^«
with it these recouiiueuchitions; and would her« observe,
that tlrt following ar<:^un)ents will equally apply, whether it
be held, that the principle of clieinical attraction is iden*
Xical with dilference of electrical state, or, ihat the principle
of chemical attraction is moditied by dilfereijce of electricdl
•tate. ; . . r

Mr, Davy '^ gpecujation rests entirely on the correct neei Certain sub-
«f hia position, relative to the •* changes and transitions by ^e au*racred bv
., electricity." He states, not as an hyjxnijesis, but as a gene- posUivt,other«
,^ jal exprestiion of fa6t, that ** hidrogeii, the alkaline tub* ^^ '^'fcU ^*
litaiiCes, the metaU, and certain metallic oxidcpi, are attracted
by negatively clcctriticd nitttallic surfaces; and repelled by
positively electritied metallic gurfacci; and contrariwise,
that oxiw^eu and acid substances are attracted by positively
electritied metallic surfaces, and repelled by negatively , ^

electrified metal'ic surface**; and that these attractive aa4 *'^*"^'* '*^*^^
repulbive forces are aulHciently energetic, to destroy or tui»#
pend the visual operation of elective affinity*.

To determine, whether Mr, Davy's statement be correct, but this not,
I selected one, from each of the classes of substances enu- ^^^^J* ^^
merated in the preceding p&rtigraph : viz. borucic a^^id,
barytes, and gold-leaf^ and 1 found, that the metal and
the earth were attracted us powerfully by an insulated
metallic ball> electrified by glass, ag by the same ball, elec- *f

tpified by fiealing-wux. I also satisfied myself by experi*
ment, that Xhe acid is indifferently attracted by a positively
©r a negatively electrified metallic surface. It iis itnpossible ^

♦o operate on oxigen and hidrogen in their uncombineti j

state, and tt>us to determine the truth of Mr. Davy's state-
wicnt, as it relatf%t» ihese substances, 'i his circumstance is,
however, the less to be regretted, a*, when analogies are 90
forcible, and so obviouf^, as in the present, instance, the
conclusions, which are drawn from them, arc received by tht
mind with a degree of certainty, little inferior to that, which
is derived from deiaonstratioii.

Simple as these experiments may appear, they are de- jhese fticts
•idedly adverse to Mr. Davy's hypothesis, the essential and

« Phil. Tf«w, 18©7, y. 3S i Journa), toI. XIX, p. 4i. ' ,

itdispcnsiblQ

•dvme to the Jn^ispeWJiVe principle of which is, that particular puJastane^

bjpothes:!. j^^^^ cwtaiu natural preferences and aversions to positively

and to negatively electrified metallic surfaces; a^ they

prove, that. noBUch preferences and aversions are evident,

while the eub.sti^nces acted on by the eltjctritied surfaces

rea)»ii3 ip ithetr aatural electrical state. We cannot, indeed*

by any rpeanB, inf^r from the reijult of ihesse experiments,

that bouieti do not exist in dift'erent states of electricity ; but

l^jq must feel saiisfifd, that an acid is not repelled by a

' pegativejy electrified metallic surface, or an earth or metal

t^' by a |X)»itively electrified metallic surface;— positions which

form a very principal part of Mr. Davy's hypothesis,

Fcculiaritiw -A sjipposition, that dissimilar bodies exist naturally in

of chemical different eUctrical states, may possibly enable us to account
action may be . _ , i- •,• p i • i i t

accounted for for n?any oi the peculiarities ot chemical action ; but I arn

by the hypo- inclined to think, fhat these peculiarities are explicable

equally on wUhout the supposition, aod t]iat the philosophical labours

other grounds, of BerthoHet have pointed out, with sufficient accuracy, the

ciccjunjstan.ces, which modify the principle of aUractio«,when

excited on tb,e i^inute particlee of matter. The question, a^

; ^ , p^esepc under consideration, did not, however, originate ia

^' the phj^iiomena of chemical afi^nity, but w^s rather sugj-

" gesUd to Mr. Davy, by thie: eltctro-motive property of hqr

ditis, and tl^e truly vMludbleidi^coveriea which have lately

beei> eigfe^'ted by me.^us of g^lvani$m.

lloHies beinr ^^» ^*^'^'' ^^ contact aud subsequent separation of two disy

indiff rent similg-r bo^iies, they are found to ;be .in di^erent electrical

afterTepari^" ^tat,f8yip r^spect tQ one another, ijnd to surrounding bodies,

tionno procf, to what tfiey were ii» before thecpptact, c,an we infer from

that f hey were j^jjg ^^.^^^ they iliu^t necessarily h^ve exititfd in difieipnt
sp beJore. •* y -

^ectricdl 6tatL-t>, ii* rt-speqt to one aaother, pre\joub|y to th«?

e^pe/imeu^- Surely not. 'Ihe electric»i«%tates, they now

j^pssefeSj have evideptly been prod up^d by coiitatt, ov ^phser

qjueiit beparatioht It may, indeed, be difficult to perceive

^(B coun^xiop lietween the ^fiect and its cause; but this

^sa^i^ot^«K^.ra t u-^ i suppO!>ii»g, ttial bodiesiijfiin dift'erent

elecnicul sta es, w> c cur most dei.cate ini^siunients assure

, us, ihat they are in sim lar tlectr ca! btaies. W a*- ii, indeed,

granted to us, that dissimilar bodies have naturally different

clectfAcal states, we could not, on this principlp, cpp^isiently

explaim

ON OHlMlCwBL AFFINITW j|5

tVplalrt tll^r'^^Ctro-motive property ; since x^e sk^ilrt ^iVK
«u|)posiin>;','tf/it they retain tlibir particular eleetrit*aF^iWu!ti*8i'
dthougH' coiitiijtrolis with cbndndtors. ' "^

Let ii'd tioir^ tufti^'Olit attention t6 iKfe |ihenonieha pro- I*^enomena o^
tJuCed during 3k.'ompo8ltioh by gatviinism; and in the first fomposiuoa,
place let usinquire, whethpr the^ caii be' accouiiteti for on the
prrnci pie6 ^jopds^d bV" Mr. 'DaVy ^^i tht^'^tcohfd (ilae* vt ife^
ther they carth'ot'be' aC^^oiinfed'fbi' cJii'jjl^iicipli* li^^rfoiyjt?^
tionable;- " ' ^^ " '^* ' "' ^''"^'-^ ^ '' '^ '^ ''"^' ' -'-^
Mad it been' proved, in the most unrxopptionable mariiief^'
tliat the pafticfes of disaimihir" kinds of mutter have differeiit?
electrical stiites,*' and that the constituents of a compound'
fetainthelr pecHiliar states while in coriiposition; the rationale,
Mr. Davy has offered of the [jHcnomena of dccompouition
by galvanism, would yet be' very far from being; satisfactory.'

If w^e take water, i^star omnium^ and consider it as a com- Water taken
pound 'of oxlgeri and hidtogen,' and these substances as^**"*'^"'^**^'
having, in respect to one another, tlie negative' arid positiYe*
states: it will by no means follow, that' oxigeh must be n^
gative, or hidrogeu positive, tor every ether body, Tn like
manner, although the' two' wires of a galvanic battery be,'
respectively, the one positive, 'the otheV negative; ^et th^^
negative wive will be positive to a body more negative than
itself, and the positive wire will be negative to a body rriore**
positive than itself, Now as far as w'c know from experiehcei *
repellent force'is not excited betwet^n electrified bodit*9,unles4
they be in precisely the same electricaV state. If therefore the
electrical' state of oxigeii and of hidrogeii remain stationary,
there \vill be only one poinf of'^o^itive electtiei'15', at'iwhitih-
ijiepositivevvire v^ilJ repel hidrogteri, and only out point of ne-
gative electricity, at which thciif gative w ire wil> repel oxigen :
and at all dtl-er'iioilits of exciffcitieht, th^ pbsitive'-wire will'
attract hidrogfeii, aiid the iiega'tive wire w^ 11 attract oxigen, " " "

Mence, as w'ater is decdrnpOBcd by the action df the twa
wires, when frbm' the circiimstiailcesundtfr which they aire i«iw»!^a-a
made to act, and from their'effects oiVour instrumVtitsi we
know, that they are in different degreed df positive and »e«J
gative eliectricity, it become*' itDpos^ibll'td consider the re<-
pulsions, IMr. Davy speaks of; as cs»ehtiul' to the decompo*
silion, sucIj rtpulsionsbeing v^J-y raVelj', if'eV^r, esieJrted': bttt*

the

f4 •'' CHFMICAL Atfiitirr,

this wliolc decomposition must be referred to the iiiie<qiiM at*
tractions of the two wires; tor each wire will aitruct hoth
<»xii;en and hidroi^en, bitt with unequal degrees of force;
.•c '. and these attractions will be modified aqd counteracted by

tjie attractions of tlie 0|>posite wire. If, for example, thi^
positive wire attract oxi^en with a force equal to 20, and
bidrggeu with a force equal to 10; and vice terstt, if the ne»
gative wire attract hidroj^en with a force equal to 20, apd
oxii^en with & force equal to 10; the efficient attraction
bttween the positive y:'}i'.e ^d oxigen would be equal to 10,
and that b^etween the negative \vire and hidro^en would be
equal to JX), and .con^equje^Uly the power, tending to sepa-
rate the, oxij^en and hidrogen, would be equal to 20. If,
tjiereibre, we ikeep in mind, that th,e effect of the two wires
increases with the di.fferepce iu their electrical state; we
must, 96 might be shpwn hy numerical calculation, 8ui)pose,
that hidrogejn is .more positive than the positive wire, and
oxigen more negative than the negative wire. On this »uj>-
|)ositiori, ^udpn no o.ther, Jt \yill appear, that, as the excite-
ment ^f the tjjrp vyires is augmented, their action on >yatj;r
should be more powerful : for the nearer the electrical state
of the positive wire cpmes to ths^t of hi.drogen, and the elep*
t^ical state of the negative wire to ifiut of oxigen, the stronger
ahould be the efficieu)t attraction of the positive wire fpr oxi^
gen, and of the oegatiye wire for hidrpgen. The. saiiie rear
«pnii'ig must apply to the decomposition pf all bodies, and
the coustituents of every bo;dy, decomposed by ^alxwhm,
ipast he x:on8 dered as huving electrical «;tates more v;idely
different, than ^re those of the pQsitive and n^gatiye wireg of
the galvanic battery. But this is shown tp be irppossible
by Sir Isaac Newtpn's experiment with the pendulum, .aud
\^y ev«fy kind of experimeot with the electrometef.
Whyifpotde- ^^d.m.ittipg, for a .{.oaeiit, th it the attractive and r.epulr
iff!^^tr/bTa ^^^ for^estQf the ro^ '^te .^^^rticles of rni^tter, aiVd the action
fcinglewire? ofgalvaitic ^jvires pn compound bodies,' are r.e;jl|y ppch as
Mr. Davy supposes, '}t would, I think, be difficult to exr*
plain, wiiy decoii). osi'io. e *r ^voJj c<"^< by j single

wire, \wvie;yf^r pon^rful may bet)ic t^atterj', with which it is
counectec); why ,de<pm position \% never effected, either by
«y^:nou or j^alvauic citcuiciry, except when Itco conduc-
. . tors.

Olf.CilEMlCAl ArFINfTr* 1ML

i-f>Tt^ itt^tfferent elrctric'ml stateii, are made to act «n !fc«t4i
«tlier.

•S^idf. Ilf ». It 13 an established fact, that ftx>in the contact Fxperimentt*
Hid s*^fiaration of dissimiUr and iosulattd metals there *^^„^^*^J^
i» pT<H^J rd such a change in the electrical state of each pnxiiiced hff
toetaJt that, after the teparatiou the cue is found to t)e po- <^«"i"t <" #»•
mtive^ the otiier negative in relutiou to fturronndui*^ nouies;
but it appeared to me, (not havinj;^ in mind tlie exf^erinients •"»'^

of W ilke and CEpious,) a matter of some doubt, whether the
alteration in electrical state is the effect of contact, or of
•eparation. To delerniine this point, in plac^ of the small
plate which usnully remains on my electrometer, I adapted a
copper plate about 5 inches in diameter. It is evident, tliut '

when this apparatus is placed on a common table, the coj)-
per plate will be connected with the wire and <;old leaves,
Lut wiJi in every other respect be perfectly insulated ; and,
jconseipiently, ihat, whenever ii state, different from that of
surrounding h>odies, is produced in the copper plate, it will
be indicated by a divergence of the gold leaves.

The apparatus, above descril)ed, being so circumstancedj
that the tin foil of the electrometer was connected with th^
Xilarth, while the copper plate, the wire, and the gold leave*
were insulated, ) brought^ by means of an insulating handle^
a z\uc plate, also about ,5 inches in diameter, into .contact
with the copper plate on the electrometer ; but although,
they remaint'd some time in contact; there was no visible
divergence of the gold leaves. Un sp^)arating the metal*;, ,wl

the gold leaves immediately diverged;; on again bringing
them .into contact, if the charge of the zinc plate !iad not
been removed, the leaves returned to their natural position;
on Jignin separating the plates the divergence took place b«,
before, and similar phenotnena ap|>eared, a^ often as the ex-
periment wab repeated. If the charge of the i^inc j)late had * ,
been removed atter the separation, the succeeding contact
did not reduce the gpld leaves to their natural state; but
left^ slight divergence in them; and when the plates were
•gain separated they diverged in a greater degree, than after
the preceding separation. Ihus, by repeating the ejcperi-
ment, and discharging the zinp plflite afiiereach.6eparation»
the divergence wa« considerably increased; not however be-

X^cio

jowi

■:-rt e^.» ?.-.$: i ?u .i»

f9n4 certain limit*, which apparently varied ucdordfinf t»
the btate of ine atmobphere as lo moi&iure: and it is
^ worthy oi reiiMirk, thai tiie oaanoer in wtnch the pla'cies are se-

parated mattimuy etiecti* the re^ulc o.^' thfe> »epa,ratioo. If
on«t be blid iilcmg the oih«r, iieith«r will evTuc* sign* ©f
'• electricity. The contact and separation ot tkvo' copper

plates produced qo feens^ble t^tii^ct on the ^oid leaves. From

I)ectitc«i these, and the experimentj ol Wilktt and (Epiuusi, I feel
5»te» of bodies ' /. , i

Tet^dered ci\U myseli warranted m coneluding, that tiie ^lectncal 6tate»

fereot by their ^ disbimilar metals, and other dissimilar bodies, a're
Thto.apj)iica- ^^ rendered different by the contact of theat: Ijodies witli
Wetorabiute q^^ another, but by their separation after contact*. I
'^ would also, from analogy, extend my conclusion tJo the aai-

l»iite p*rticle» of dissimilar Wrid's^of matter ; aud woB^d^say,
that irhen in contact, as in composition, they possess thei^r
natural, or, as I have endeavoured to show, in similar elec»
trical states ; but that on their separation, as in deijom po-
sition, thej^ acquire electrical states different from whljt'they
bad while incontact, and cortseqliently different from theii*
natural electrical stales ; and that from snch change in the
electrical states of the constituents of a compound, in don-
sequence of separation, analogous to what takes' |)ldcfe in
fcspect to the voltaic plates, the one set of particlies'b<?comes
relatively to the Earth and surrounding bodies positive, thi
other set negative.
Stt position '^^^ experiments, to which I have jnst alluded, appear to

•hattbemctal* me perfectly sufficient to point out the fallacy of the' ex-
inthegavYaaiCpjj^j^j-^^^^y^^^.|^ j^^,^^.^ generally received, of the excitfemeti^
ibreKt states, of the galvanic pile; the whole of which rests on theassump-
c*ioB€ftB&f tion, that dissimilar metals, while in contact, aro'in different
electrical states, the one being relatively positive, th*- othe^
negative; which has been shown to be perfectly untenable.
The following also 1 consider as additional and weighty ob-
jections to the hypothesis. 1: The voltaic pUitesdnly net
when applied to each other by esttensive surfaces.' Ih the
present roost improved galvanic troughs, the mi^talaha^e'c^Wi
nected together by comparatively few^ points, an<^*the cbh4
trivance has not only rendered the apparatils more conve*
}ik\ ent for U8e> but also' morei powerf u 1 . 2, Volti'fc plates at^

..'•.■ . / ,,■. •' . • ^ . •'- -nft

• An account of the experiments of Wi'ke and of CKpinus will be found
Mi Dr. Priestley's Histiwry of .jfcleciriclty,

only

ON CHEMICAL AFFINITY. fj

only when the polish of their surface is preserve<l ; the cop*

^r and ziuc plutes pf a galvanic battery are always very

much tornished. a. The j^alranic apparatus can only be

excited by a decomposable fluid, and this fluid is always r

decomposed, when the upp'<*'tttus is excited. From thcs^

confiidevatiqns, I am iucliued to conclude, that the princi^

pies, on which decomposable fluids act in producing their

peculiar elfe6^8 on the galvanic battery, li^ve u.ot y^t be.ea

accuriiteiy determined, 5->fH iij,- ^m^-tta -m* t3 •*•?•

It will be a general, and I think perfectly correct statf*

ment of tive facts, reUitive to the decomposition of bodies by The difference

ifalvanisai, to sa\, tliat hidroi>:<in, the alkali^, the metals, ?'^ ^'^^'; " <»^'
1 ,,• • 1 . ^■ ^ r ^ ■ Jng to deconv-

and certain metalhc oxides are, immediately utter their se- poition haT-

partition by galvanism frpi?^ oxigep, and from acids, found '"S ^^^^

qt the negative wire; and that oxigen and acids, after their

sepfiration from the first claw of snbgtanccis, appear at the

positive wire. I trust, however, that the experiments and

r^easoAiings, which I have adduced, a»e sufficient to prove>

th4t th<i partic«es of dissimilar kinds of matter do not e^iist

in ditJetent electrical S'tateiS while in composition, but th^l

they acquire a difference of, electrical state in the act of

deconxposition : this difference of electrical atate is, there-

fhre, not the cause, but the effect of decomposition.

It yet remains to be determined, on wiiiit. principle the
<4)posite wires of a galvanic battery act, . when, their aclioa* How is decom-
oGcasions the sep.iration of the constituents of compound ^^^"^^"J^^''
bodiiei^. To do this, I by uo means conceive it necessary tO'ism?
eater i'nio an investigation of the remote cause of electrical
pfaeK^mena; on the contrary, I think the question may be
decided by a reference to well known and undoubted facts.

If two conductinj^ b/)dies, in different electrical states,:
be brought near to each other, the djfferenoe will h«^y * ''spuUve
destroyed; and if the difference between the <^^e<^'<^'ical gou* to that of
states of the conducting bodies be considerable, while the caloric.
operation is going on by which it is removed, the con?*
ducting bodies will frequently be fused. Thi» happens not
only to bodies easily fused, but also to very refractory sub-
stances; as the alkalis, thp eartha, the metals. 'Ihe fact di-
vested of hU hypothesis is, that the action* of differently
eWctrified conductors •ccasions a repulsive force to be ex^i^

erte4

erteH between i]ie pririicles of the conductors, iitid tji, in ih'tt
TC»\iecU precisely analo<j[OU« to thai power, winch in th«
]anij«e<Te of mod«»rn chemistry is Heuominatecl caloric.
MckI* in which ^* ^'^i^ ^*^^" ^"'^K known, that caloric, aided hy the affinity
♦kis i« «fFected dif a sobstance for one of the eleaaeuta of a cunuiound, i»
in the case of _ . cr i ^ • /• i . i

eal(4ric> sufficient to etrect the decompo«iiioii of tlie componn<l* ana

this fact is particularly ohRervuble in thi» rediiction of me-
t iilic oxides, by heating then> with iniiammabiek, or metals.
By these means the French chenniiits have lately •ucceedcd
in their attempts to decompose the i\xed alkalis, and have
»; • obtained, in an uncumbined ^tate, tlicir constituent ele-

ments, whleh appear to be oxic;evi, and a metallic base. The
rationale of these decompositions is snfiiciently obvWus.
The repulsive force of caloric separates the constituent par-
t»c)efi of the compound; at the same time, by diminibhin}*
the cohesion of the inflammable, or uncombined metal, itJ
renders its attraction for oxi<»en efficient ; and hence the
separation f^f o^xi«:jea from the oxide, and its combinatiort
with the \inc(^inbined metal, or with the inflammable, The^
<>xigen, enterir)g into a new combination, is removed froiiii
the sphere of chemical action, and thus its reunion with the'
metal, from whicb it had been separated, iii preyented. '»

ana >n that of The decompositions by galvanism will, I think, admit oR
j5«tT»Bisa. explanation on similar principles, The action of the two
•riretofthe j^alvanic l>attery occasions such a repulsion, at »>
certain number of points, as separates the constituents ofo
the compound, which is made a part of the circuit, and?
which must possess a degree of conductiuj4 power. The se-#
psration of the particles of dissimilar kinds of matter, whicht
had been in c^ontact, produces different electrical states inf-
tbera: the one ?et of particles is, consequently, attracted
with greatest force by the poMtive wire, tlie other set of par-?
, tides is attracted with j^reatest force by the uegative wire ;•

the separated particles are thus placed beyond the sphere/
6f chemical action, and their reunion does not take place.

Hrtvinj;, then, considered at some length the question pro-..
posed by Mr. Davy, 1 am salisfted, that we cannot admit thet.
Kypothetiis, which refers chemical phenomena to the elec-*-.
trical energi%r« of the particles of mailer. 1 am willing to
ifclWsy, thatitishi^ldy ingtniaus, and tbac at^rtt sight it U^s

really

ok THE tOLTAIC BATTKRT. ^

really tfie appearance of a simple generalization of farts:
but I think it has been shown, that the assumption on which
ii rests is contrary to experiment and analogy ; that th^ as-
sumption is incapable of explaining the phenomena on ac-
count of wliich it was taken up ; and that the?.e phenomena
can be explained on iniiiciples unconnected with any hypo-
thesis, and which are the result of etperiaient^ahd bbservs*
tion.

Hi. :«•:

ObsfirraNons on the l^nitivg, or Wire-melting Power of the
Voltaic Battery, as proportioned to the /lumber of Plates
tmp!oi/ed; with an Account of some Experiments on this
Subject y made in conjunction with Mr. John CvTiiBEB/rsoN ;
bi/ Mr. Gkorge John Singer, Lecturer on Chemistry
and Natural Philosophy. Communicated by Mr, Singeiu

AN a lecture recently delivered at the Royal Institution, Inquiry coa-
Dr. Davy detailed some experiments of the French Phijo- ce""»JJ '^» ^'
sophers, made with the mtention or ascertHinin<^ the pro- gr of igniting
portion, in which water is decomposed by different Voltaic ^^"*'' "» ^^':
combinations, the number of plates beinjj subjected to va- nUna by Mr,
ritttion. After some observations on the probable source of i>a^y«
inaccuracy in these experiments, he proceeded nearly as
follows: ** There is still another very interesting subject of
** inquiry, which has not yet bten touched on ; 1 mean the *

** proportion the igniting power of the battery bears to the
*• number of plates employed." The Dr. then proceeded
to exhibit some experiments on this subject; they were ^

made with a new apparntns fitted U[) in trouo^hs of Wed«}^-
wood ware; the size of the plates 11 inches, by 4f inches. •*-"'t>

The result of these experiments was very equivocal, two KuomiVifsxn^
batteries ienited four times the lensjlh of wire ignited bv ' ^ *^^^'^^''
077<? battery ; init six batteries ignited little more tfmn twice
the length that three could ij^nite. Dr. Duvy supposed,
that the rate of im»itiou mi^ht vary in hij^her numbers,
•bt^yiui^- a diflvrent law to that vvhich obtanis wben^a few

plates^

J^ ON THB VOLTAIC BATTER V#.

plates only arc employed. "Every practical electrician wonld.
however, I am convinced, refer the anomalous results of
these experiments to some inaccuracy in the apparatus, or
to a difference in the density of the fluid with which the
batteries were charged ; as the irregularities obtained were
by far too considerable, to have been produced by a differ-
ence so trivial os that existing between the number of plates
employed on this occasion. The authority of a philoso**
pher, so highly and so justly celebrated as Dr. Davy, may
give extensive and respectable circulation to even palpabU?
errours; it is therefore the imperative duty of every genuine
friend of science, to exuminfe Assertions flowing from such
a source, and to give to the public any facts he may be
acquainted with, that militate against, or contradict them.
Experiments As early as the y^ar 1904, dirCct experiments were made

on the subject ^^ ascertain the duantity of wirei ignited by different iium-

made some . 7^ \- t Vv -r^

years ago. d^*"^ of pmteS. Of tnts! I presume Dr. Davy v^as not aware,

when hd stated, that ** the inquiry hdd not yet been touched
cnf* he may not have read the 18th tolurae of the Philo-
•ophical Magazine, or the 7th and 8th volume of Mr,
Nicholson's Journal, or Cuthbertson's Practical Electricity,
■where an account of these experiments is published. lit
the 7tlj volume of this Journal, page 207, a series of expe-
riments with large batteries of plates of 4 inches, and of
Thepow^^of 8 inches square, is detailed by Dr. Wilkinson : the results
J"'*^^" *.^ ^^ of these experiments prove, that the power of ignition in"
the places. creases in direct proportion to the number of plates employed;
and this law «f increase is uniform, whatever be the size of
the plates. If a battery of any given size melt any deter-
minate length of wire, two such batteries will melt twice
the length, three iuch batteries will treble the effect, and
by four it will be quadrupled^ provided the acid with which
they are charged is of equal strength.
Other experi- In the 8th volume of this Journal, pnges 97 and 205, »
meats gave si* yg,.„ accurate series of experiments is given bv Mr. Cuth-
«ilar result*, ^ _ n-,i ii.,7

bertson. By a variety ot trials he proves, that double the

quantity of plates burns twice the length of wire; and he
points this out as a distinction between the action of com-
mon and Voltaic electricity, but concludes, that the dif-
i#rtnc<i arises from the imperfection »f the Voltaic appara-
tus ;

ON TH« YOLTAIC BATTERY, 3I

t««; ^.on one occafeion be obtained a ditferent result by with oi?€«.
employing very larg^e plates arranged as a pile. In «ubse- ^
quent volumes of this Journal are several other papei-s on
the »fi(ihe sobject ; but enough has been quoted to show,
that the inquiry has not any claim to originality. The con-
clusions of the first experimenters are however at varianice \
with those of Dr. Davy, Dr. Wilkinson and Mr. Cuth-
bertson suppose, that the igniting power of a battery com-
posed of plates of any given sire increases in direct propor-
tion to the number of plates. Dr. Davy infers from his
experiments, that, when a few plates are increased, the in- ir
crease is as the square of the numbers ; but iu combinations
of greater extent the effect does not increase so rapidly.
The apparatus employed by Dr. Davy differs in structure As the appanc-
from that of the earlier experimenters; and as this miffht *"'^*f '^V*f
occasion some slight difference in the results, I did not con-
sider it justifiable to decide on the accuracy of either, with-
out new trials. With the assistance of Mr. Cuthbertsoa the experi*
the following experiments were made ; their results furnish rnects were
toine useful practical }nf<>rmation in addition to the ascer-
tainmeut of the object, for which they were expressly insti-*
tuted.--.;;; '-, • . ■ 4, .. .'•

The acid mixture employed to charge the batteries was The add rm-
of the same strength in oil the experiments, (beiog pre- P^®/^*
viously mixed in a large vessel for this purpose). It con*
iisted of 10 gallons of water, 5 lbs. of strong nitrous acid.
And half a lb. of muriatic acid. A mixture of this kind
being the most effectual wire-melting charge. Ten bat- The apparatus,
teries, each containing 10 pairs of four inch plates, fitted .c r .

up in troughs of W^edgwood ware ; and one batten-, of 50
pairs of plates of the same size, titled up in a wooden
trough, with glass partitions, constituted the api>aratus '> cr I

employed. The plates in the troughs of Wedgwood ware
were new, but the glass partitioned battevy bad beeo fre*
qtaently employed before. »

Two of the Wedgwood batteries render^:, nine inches of Exp, I,
iroii wire, ^^ of an inch diameter, faintly red hot, when .?lwwpff -kr*^
the contact was first made. This effect continued but n ....

very short time. When it had wholly ceased, an interval of
ooe toinutp was; aufBered tq eUpser and. &t %h^ end q£ tbb

m:n0Kii time

flf Of« TUS VOLTAIC SATTiar.

time the contact wtt» a^in made. Three Hvcher^ th#
oaint* wire were now rfticlered red hot with the »anie ap-
ptrtifance a? the niae irichef* in the (ir*>t expf^rimcnt.

»my. f. Four Wedj^wood batteries were iHXt employed. At the

firit contnct lb luches of the same wire became aliglitlj r<«i
UQ$rl and the coutact was preterved^ till the effect of i^ui*
Mpn eutireiy terminated. One minute was suffered to
elapse, when, on removinj^ the ceutaet, 6 incites of wire
were ignited in the same degree as in the preceding eNperi*
aicuts.

Hh^S; An interval of three tninntes was suffered to pass with*

•ut contact; >\l the end of this time, two batterit-s rendered
MX inches* of the Kanie wire red hot, and four batteries pro«
duced asimihir effect on li inches.

ftevtrkt. Theunif»im result of the-e experiments, in which the

rjnitiiij* power increases in the same proportion, however
rariuble the action of the battery, renders it hi<;;hly prol?a-
ble, that in Dr. L)avy*«» experiments the biiiterics were ac»
eidentally char^trd with acid mixtures of variable strength,
the increase in his first experiment being as the square of
the numbers.

|[^^4, To ascertain whether the ratio of increase continued the

same when a larger combination is employed^ ten bat-
teries were charged with fresh acid, of the same stren}^th«
Five of these ignited at the first contact Itt inches of the
same wire as that employcHl in the former experimeotb ; and
on repeating the experiment with ten batteries, an eifedb
pn^cisely similar was produced on 36 inches.

Exp. 5. A short interval was suffered to elapse, when five batteries

ignited 15 inclies of wire; and the same effect was produced
on 30 inches by tea batteries.

Exp. 6. Platina vrtre, rVtr^h of an inch diameter, was taken. Tew

batteries (^a a diminished state of action) maintained a wliit^i
heat in 5 inches of this wire. On repeating the experiment
with five batteries a similar effec-t was produced on 2^ inchtt
of the flame wire.

Th« power in These experiments indicate, thnt the conclusions of Dr.

ciiract propor. t^jn^^n^Qj, ^n^l Mr. Cuthliertson are legitimate j and ther

tlOO to tnO ,

•umber, prove al*o, that the iirnitinff poictr not only %nr.rea$es m exact

proportion to the number of plates j but that tbi«r.itioof

iocrease

ON THE TOLTAIC BATTRRY* Q

increaie i« uniform, however variable the action of the bat-
teries may be.

The trottfi^ fof Wedgwood ware have the partitiotif, The contlnu-
which form their cells, at u j^reater distuncc from each other, acUon depends
thmi thut of the gUss partitions in the wooden trough ; they more on the
ofcourHe require uiorL* ucid to exeite a ^^iven H"''"*'*y ®^ Jiie ofVhe *
plates; and it has been Haid, that this circumstance promotes celli.
the contiiiuaucf of their Hctioii. The results of my experi-
ments Hpeak u different language. The continuance of
the action i» influeirccd much more by the nature and
fltrenglh of the acid mixture ; and 1 have not obnerved, thut
in any case the separation >of the partitiong to a greater dig-
tance than ^ths of an inch is attended with any advantage
in this rcMpcct.

At the commencement of the preceding experiments, a Glatt pnrtUU
glass partitioned battery, of 50 pairs of four-inch plates, **"*^ **"*'^3'-
was iilU'd with the Hanie acid mixture as that employed in
the troughs of W«'d^wood ware. Its action was greatly
inferior, in consequence of the oxidatid state of the plates
from forujer operations; but the continutince of its action
appeared precisely similar, and ut the conclusion of the ex-
periments the eftects were so nearly alike, os to admit of no
perceptible distinction* At tl>e iirst contact 9 inches <»(
wire were ignited, and by allowing an interval of live mi-
nutes a Kinular ettcct was produced by u second contact; a f^attrrie* r©»
circumstance which proves, that the voltaic battery requires, *!"''« ^^"»« w
like the electrical machine, time to ptoduce its full effect, fJn^fSct'.
This fact, OH indicated by the sensation produced on the
animal organs by a Beries of 6oO small plates, >va» noticed
many ye«r» ago by Dr. Wilkinson.

The preceding arc part only of a series of inquiries on
this subject, which have long occupied my attention, and
which 1 purpobc to dctud in future numbers of the Journal;
anxious only, that iu experimental science assertions be sup-
ported by accurate experiments; and that, in the progress,
of pliilohophical dibcovery, the merit of the iirst lalK>urerf
be not fofgotten amidst (he ^chieveinents of their successors*

Wo. 3, Princes Street^ Cuviudish Sauure,

54 EFFECT or MAGNETISM OTJ TUBES.

On the different Forces tcith which Tubes, Bars, and GyJin^
ders, adhere to a Magnet, In a Letter from Mr, E.
Lydiatt.

To Mr. NICHOLSON.
SIR,

Jl HROUGH the medium of your scientific Journal I
am anxious to obtain information on some magnetic pheno-
mena, which 1 have lately noticed to ]\ave taken pU\ce on
applying? difierenl shaped conductors to connect the poles
of a horseshoe mat^net.

In preparing the introductory course of lectures on the

Ar iron tube philosophy of the mechanic arts, which I have delivered this

connecting the ic--/«i-- tii

poles of a season at the ocientinc Institution, 1 had occasion to make a

horseshoe f^^y experiments on the magnetic property of iron and steel ;
hered with ^" ^^^ course of which I happened to place a piece of iron
freatforce. tube in contact with the two poles of a horseshoe magnet
composed of thin bars; and found to my surprise, when I
attempted to remove it, that a considerably greater force
was required, than that necessary to seuaiate the conductor
which belongs to the magnet, which, as usual, was a square
piece of iron with a ring attached, ai.d presenting a flat sur-
face equal to the combined polar surfaces of the three bars
cortiposing the magnet. This striking singularity induced
me to ascertain the relative force required, to overcome the
different degree of attraction.

I firsf applied the conductor belonging to the magnet.
Its adhesion to and, by suspending weights from the ring, found, that it
23l^ll^''''" kparated with 5lb. I then supplied its place with the tube,
which was a piece of gun-barrel about two inches in length,
attached longitudinally from one pole to the other ; and by
passing a wire through it, and twisting the two extremities
into a hook, I suspended the weights, and found that 1 li|b
were requisite to separate it from the magnet. From this
experiment it will be evident, that the relative degree of
attractive force, exerted by the magnet on these two differ-
ent conductors, is as 10 to 23. 1 repeated the experiment
get eral times, awl the results were invariably the 9ame.

The

n#:>

ON THE NATURE OP POTASSIUM AND SODIUM. JJ

" The line of contact of the tube, when the weights were Change of p».
first suspended, traversed the poles of the centre bar of the duc^d no*"l-
niagnet only; but while they remained attached, I turned terationinthe
the tube till it stood in a diagonal direction with the extreme *ff«ct.
angles of the outside bars; but no difference of attraction
was indicated, as it would not sustain more, or separate
with less weight, than in its first position;

I then increased the width of the line of contact in the On increasinf
tube, with a file, to about ,V of an inch, and found that it »he contact by
separated with nearly a pound less weight: I increased its facef the at- '
width still more, and the attraction was proportionably less, traction dimf- *

This led me to suppose, that the extraordmary degree of
attractive force, by which the tube was held to the magnet Under^ adhered
in the first instance, depended entirely on the minuteness '"°'6^'^«^ly
of the line of contact; and of course, that a solid piece ^* * ^*
of sound iron of the same diameter, would be similarly
attracted. To prove this however, I procured a solid cylin- '
der of iron the same length and diametier as the tube; but
upon applying the weights, 1 was surprised to find it sepa^
rate with less than half what was necessary to displace the
conductor belonging to the magnet.

These hitherto unexplained, and probably unobserved,
phenomena, are submitted for explanation to such of your
philosophic readers, as may have paid more attention to
this subject, than I have had an opportunity of doing;
in hopes of being gratified with some communications,
which will not fail to be interesting, while they elicit a more
extensive inquiry into that mysterious and neglected princi- "'^

pie of nature, magnetism.

Yours, &c.
London, April the 10/A, 1811. E. LYDIATT.

V.

•An Answer to Mr, Murray's Observations on the Nature of
Potassium and Sodium: by Mr, John Davy,

To Mr. NICHOLSON.
SIR,

;

♦»&*!

R. Berthollet has estimated the proportion of water in Quantity of
common fused potash at 13*9 per cent ; and Mr. Davy, from water in pot-

Ds „""•

9fi

Mr. Dtry»«

ffundard pot'
ash.

eoiabiii«d

-with bo rack'
•cid without
•Tolution of
water.

Common pot.
ash does not.

Combustion of
potassium in
oximuriatic
gai.

DiffiererT'e be
tween the
pure alkalis
andiheirhi-
tfrates.

Fercxides of
potash and
•«da.

OV THB NATCR* Of POTASSrUM AND SOpIUM.

an etperiment on the action of silex on this hidrate^has con-
cluded in his Bakerian lecture for 1809, that it contains,
taking the potash formed by the combustion of potassium as
a standard, about l6 or 17 per cent.

In the same lecture he has shown from the quantity of
fused muriate, produced from a j^iven weipjht of potassium
in muriatic acid gas, that his standard potash has a much
greater saturating power, than the hidrate of potash ; that
XOO of the former wiil neutralize the same quantity of acid
»s 120 of the latter.

He has since ascertained, that, when potassium and
powdered boracic acid glass are heated together in a tube of
plat'ma, both with and without red oxide of mercury, no
water or inflammable gas is produced; and that the result
is the same, when potash formed by the combustion of po-
tassium is combined with boracic acid.

On the contrary, substituting the hidrate, or common
fused potash, he has in one experiment actually collected
about 15 per cent of water; and the loss of weight after the
combination of the acid and alkali, in other similar experi-
raents, indicated from 15 to 20 per cent.

He haa found too, that the only product of the combus-
tion of potassium in oximuriatic gas is fused muriate of pot-
ash ; that the same salt is fotraed ; and oxigen gas evolved,*
without the least appearance of water, when potash from the
combustion of potassium is used ; and that water as well as
oxigen is separated when hidrate of potash is employed.

In addition to these circumstances, which are stated in Mr.
Dary*slast Bakerian lecture, a copy of which he has allowed
me to peruse, there are physical properties also pointed out,
distinguishing potash and soda from the hidrates; the former
for instance, require a much higher temperature for fusion
than the latter, and possess greater hardness and apparently
greater specific gravity.

It is Weil known to those who have attendefl to the l^te
progress of chemical discovery, that potash and soda are only
to be procured by the rapid combustion of the alkaline
metals, or by the after application of a red-heat; and that per-
oxides are formed whe^ the combustion is feeble either in
«xigen gas or common air. Messrs. Gay-Lussac and The-
. . ' nard

ON THE NATURE OP POTASSIUM AND SODIUM. Sf

nard first distinctly pointed out the nature of these per«

o^ide8,,aiid described their properties. According to thejt

litatement, the peroxide of potassium contains three times

the quantity of oxigen that exists in potash, and the per« ,,.-f ....

oxide of sodium half as much more as exists in soda** These

oxides have also been examined by Mr. Davy, and the

general results of his experiments are conformable to those

tf the French chemists.

Messrs. Gay-Lussac and Thenard, using the same tesf Trials of the
■8 Mr. Davy had before applied to their hypothesis, making !fJ^e*^Qnii» '
comparative trials of the saturating powers of the alkalis alkalw.
formed from the metals and of the common hidrates, were
convinced, that potassium and sodium are not hidrurets; t^tf

and consequently they adopted Mr. Davy's opinion, that
they are simple bodiesf .

Mr. Murray controverts this opinion in his paper, published
in the last number of your Journal : rinding that potash v»i»rfW6il5|t
from the combustion of potassium, has much the same sa«»
turating power as hidrate of potash, he infers, that th^
metals of the fixed alkalis are compounds of unknown ba^et
and hidrogen. As this gentleman does not describe tbt , ^ ^^:.. .,^^^.
manner in which he formed his potash; there is every rea* 'yci

son to conclude it must have been by combustion in th« ^'* '

atmosphere, in which case, it would have been principally
peroxide; and an equal weight of it ought to have less satu«
rating power than an equal weight of common puta«h. SincCj,
thereibre, Mr. Murray's hypothesis appears to be un»
founded, since it is contradicted by the ample statement oC *^ *^^ '^ -
clear and decisive facts already made, I shall conclude ^'w i

without examining the speculations comiteted with it. ' . 7 [.^

I am, Sir, with great reject.

Your huxnbk servant,

London, March Uth^ J. J>AVT.

1811.

* Moniteur, July 5, I8i0.
-f At the end of this paper will be fouad a notice of these gentlemen^c
«xperiaient6^ it is part of a Report of th« Inttitute, publiibed in the Mo>

Bitenr already referred to.

Extract

ss

KXTBACT FROM T0& MONITEUK.

Extract from the Moniteur qfJuIi/ the 5t/i, 1810, referred fi
in the preceding paper- Translated from the Frmch hy
T. O.C.

y efoxidcs of
the alkalis
treated with
acids.

Inferences,

Quantity of
■water in the
alkalis exa-
mined.

Jl H^^E oxide»^ [the peroxides] present with some acid
gasses ph'.iiomeiia worthy of attention. Messrs. Gay-
Lussac and T henard observed, that with carbonic acid gas
the result"^ were, an alkaline carbonate and an evolution of
oxij^en gas: that with sulphurous gas and oxide of potas-
giura a sulphate and oxi gen were obtained; and that with
this gas and oxide of sodium the produce was only a great
deal of sulphate and a little sulphuret : that not the slight-r-
est trace of moisture was given out in any case; and that the
weight of the products obtained corresponded precisely to
those of the oxide employed and the acid absorbed: Now
as in the combustion of potassium and of sodium nothing if
evolved, or no volatile product formed ; we perceive, that, if
these metals be hvdrurets, it is a necessary consequence,
that the sulphates and carbonates of potash and soda, and
no doubt all the salts that have these alcalis for their base,
•ontain as much water, as the hidrogen of these hidrurets
ean torm by combining with oxigeu, and that they retain it
at a very high temperature; which is possible, but which
nothing has hitherto proved. If it were so, a farther conse-
quence would be, that potash and soda contain much more
water, than Messrs. d'Arcet and Berthollet admit in them :
for these alkaliw would contain not only the water which is
extricated on combining them with acids, but likewife that
which the fait formed is capable of retaining. It was of
fome use to determine directly the first of these two quan-
tities of water; and this Messrs. Gay-Lussac and Thenard
have ^one» For this purpose they qqnvertjed into alkali,
gradually and by means of humid air, feveial grammes of
potassium and sodium, and saturated them with sulphuric
acid diluted with water. On the other hand, having em-
ployed the same acid to saturate pure potash and soda that
Jiad been heated red hot; and having taken an account, in
all the saturations, of the acid employed, as well as of the

m«till

ON THE NATURE OF OXIMURIATIC GAS. 59

metal or alkali employed also; it was easy for them to de-
duce the consequence they sought. Thus they found, that
100 parta of potash contain 20 of water, arid that 100 of soda,
contain 24, supposing potassium and sodium to be simple
substances. They have even veritied this quantity of water
with respect to soda, by treating over mercury in a curved
jar a given quantity with a quantity, also given, of dry
carbonic acid gas. The soda was placed on a small plate of
platina, and gave oat so much water the nioment the tem-
perature was raised, that this water trickled in abundance
down the sides of the jar. We can even by these mean?, or
by sulphurous acid gas, render the water sensible in 2 mil-
lig. [0'03 of a grain] of soda or of potash."

VI.

On the Nature of Oximnriatic Gas, in reply to Mr. Mueray.
By Mr. John Davy.

f To Mr. NICHOLSON.

SIR,

R. Murray, in his answer to the remarks which I ven- Mr, Murray
tured to make on his former paper, appears principally de- ^''"^'^1^'"^ ^''

- r .' Davy s theory

sirous of showing, that what my brother, Mr. Davy, has as hypothe-
advanced as a theory respecting oximnriatic gas, is strictly '•'^^'*
an hypothesis. The conclusiveness therefore of Mr. Mur-
ray's answer depends on his success in proving Mr. Davy's
views hypothetical ; if he fails in this respect, he fails alto-
gether, and the old hypothesis loses its asserted claims to
attention.

Mr. Murray first affirms, that Mr. Davy's theory is not ^j^j^. ...
a simple expression of facts, as I have represented it ; that fact.
it is not a fact, that muriatic acid gas is a compound of ,0

oximuriatic gas and hidrogen, but an inference; and that
the compositions of all the oximuriates are similar infer-
ences. This I cannot admit. In the formation of muriatic
acid gas, no substances, but those just mentioned, are con-
cerned; the weight of the compound is the exact weighjk

4d OS THE NATORZ OF OXIMURIATIC QAS*

of the two gasses era ployed — nothing ponderable escapes ;
muriatic acid gas consequently is not inferred, but is im-
mediately perceived to be, a compound of oximuriatic gas
and hidrogen, and all other cases are analogous.
Mr. Murray's Mr. Murray, to convince me of the errour of which he
from 'the°com- conceived me guilty, respecting the nature of Mr. Davy's
bination of ox- theory, has recourse to particular instances to illustrate his

ind mmlatk'' •'■•^"™^"^- ^^"^ ^^^^ * " ^ combine oxide of mercury and
acid, muriatic acid, and form calomel, I conclude therefore, that

calomel is a compound of oxide of mercury and muriatic
apid. I combine muriatic acid and potash, and by dissi-i'
pation of the water I obtain a solid product, which I con-
sider as a compound of the muriatic acid and potash, and
I perceive in these conclusions no supposition, but a simple
expression of facts." If Mr. Murray can combine oxide
of mercury and muriatic acid, and form calomel, I havg
no objection to his conclusions; if the above is a simple
expression of facts, the theory which expresses thofse facts
noqst be ^correct. But 1 have not been able to witness such
facts. I have found, that, when muriatic acid gas is ad-
mitted into a., exhausted retort, containing red precipitate,
cprrpsive sublimate, and not calomel, is formed ; that water
in plenty is simultaneously produced ; and that much heat
is generated, sufficient indeed, when the experiment it
made on a pretty Itirge scale, to revive some mercury by
the expulsipu of jts oxigen. Mr. Murray, not attending to
all the phenomena, has formed a false theory. Stahl, tinding
sulphur produced by heating charqoal wjth sulphuric acid,
asserted, that sulphur is a compound of sulphuric acid and
phlogiston ; and Mr. Murray, Jtnowing that different me-
tallic compounds may be procured by treating different
oxides with mpriaiic acid, a^sfsrts, that these compounds
consist of muriatic ^cid and metallic oxides. In Stahl's
famous experiment, carbonip acid gas, not being then dis-
covered, escaped his notice; but the same cannot be said
<of water, which Mr. Murray has thus neglected. The
preceding illustration of Mr. Miirray at pncp demonstrates
Ihe real difference between Mr. Davy's theory and the ol4
byppthjesis; and tl^at the former is^ as 1 have represented it,

a simply

•ON TriK NATURE OF OXIMURIATIC CAS. 41

a simple expression of facts, and the latter a series of sup-
, positions.

I shall studiously avoid discussion in the remaining part
of this paper: it is my intention to confine myself to facts,
which speak for themselves, and are the only legitimate
l5upport8 of a theory.

Mr. Murray asserts, that Mr. Davy is obliged to sup- Water pro-
.posCf that water is produced in the common mode of mak- oxide of man-
, liijy oximuriatic gas from muriatic acid, by means of the ganese is heat-
black oxide of manganese. Mr. Davy has ascertained the acid gaT.""*'^*^
fact, that oximuriatic gas and water are produced, when ^

black oxide of manganese is heated in muriatic acid gas.

Mr. Murray imagines a great intricacy in some parts of Mr. Dayy's
Mr. Davy's theory, which does not really belong to it; for gf^^'i^^J'*
theory, being an expression of facts, must be as simple as Mr. Munay
/the facts themselves. Mr. Murray, for instance, conceives, supposes.
/|bat, in the solution of muriate of potash in water, water
is decomposed ; and that it is recomposed at the moment
of its expulsion by heat. These are conjectures. In Mr.
pavy's theory, fused muriate of potash, I conceive, is a
compound of oximuriatic acid and potassium ; and the so-
lution of muriate of potash is a compound of oximuriatic \
acid, potassium, oxigen, and hidrogen. The mutual de«
composition of nitrate of mercury and common salt is ano^
ther supposed complicated instance pointed out by Mr.
Murray. It is this gentleman who imagines the changes
complicated. The facts are merely these : sodium surren-
ders its oximuriatic acid to the mercury, and receives in
return its oxigen and nitric acid, and thus calomel and ni-
trate of soda are very simply formed.

Mr. Murray seems to consider every thing anomalous. Tilings not a«-
that is not accounted for; thus the want of action between always anoma-
charcoal and oximuriatic gas is in his opinion an anomaly lous.
in Mr. Davy's theory. Can Mr. Murray account for the
want of action between charcoal and nitrogen, and between
the metals and nitrogen ? and, if he cannot, does he conse-r
quently consider these facts anomalous .-*

Mr. Murray doubts what I have alleged to be fact ; viz. Mercury de-

that the composition of muriatic acid cas is uniformly the c°"?Pose'5 mu-
-, , /. , -M^ riatic acid ga$

game. 1 do not pretend to accoimt for the results of Dr. and forms ca.

Henry's ^^*^-

A4^ OS THE NATURE OF OXIMtJRUTIC GAS.

Henry's experiments, on which he rests his doubts. I have
observed, that, when muriatic acid gas is left in a jar over
mercury, the acid will slowly disappear, calomel will be
formed, and at length nothing but hidrogeu will remain.
Carbuwtted ^ h^v® stated in my first paper the general re.-ult, that

hidrogen and carbonic acid is not formed, when dried carburetted hidro-
donot form 8*^" IS detoixated over recently boiled me c ry with an ex-
cwrbonic aoid. cess of oximuriatic gas. Mr. Murray wishes to know how
1 ascertained this fact. — I considered the precipitation of
charcoal, and no cloudiness being produced on passing the
residual gas through lime-water, sufficient evidences of
this.
I>«iQo»tion of ^*'* Murray objects to the mode in which his experiment
hklroget), oxi- OQ the detonation of a mixture of hidrogen gas, oximuriatic
aind'^^rb<Mvic g^^» ^"^ carbonic oxide, was repeated, and is not satisfied
Oi^ude. with the results which are in opposition to his own, I have

assisted my brother in again making this experiment ; Mr.
Hatchett and Mr. Brande were prehcnt. A mixture, con-
sisting of 14*6 measures of oximuriatic gas, of 4 measures
of hidrogen gas, and of 10 measures of gaseous oxide of
carbon, was inflamed by an electric spark over recently
boiled mercury; a condensation of half a measure only was
produced by the explosion. Pure ammoniacal gas was
added in excess, and, after the admission of water, there
remained 13 measures of uuabsorbable gas. Eight mea^
sures of oxigen being introduced, the mixture was inflamed;
-there was a diminution equal to 4 measures, and 8 mea-
sures of the residue were absorbed by a stropg solution of
potash*.

Now the 8 measures of carbonic acid gas formed indicate
8 measures of residual carbonic oxide ; aud, when the com-
mon air present is taken into account, with the difligulty

♦ The oximuriatic gas nas procured from a mixture of commcp
talt, black oxide of manganese, and diluted sulphuric acid; t^e 14
measures employed were found by a comparative trial to be contami-
nated by 3 measures of common air. The other two gasses had been
previously dried by potash- ITS measures of the carbonic oxide,
detanated with l65 of oxigen, were immediately diminished to 19 j
aud by ai»itatioa with a strong solution of potash, there was a farther
diipinutiou produced equal to 11 measures.

ef

ON THE MATURE OF OXIMUHATIO CAf. 43

t>f effecting the entire exclusion of moisture, no result

more satisfactorily conclusive, that no carbonic acid was

formed, could be expected : and we obtamed a similar re-

iult ill anotlier experiment, in which we employed a strong

solution of potash instead of ammoniacal gas, for absorbing

the acid ^as formed,

1 mentioned in a note to my former paper the discovery Compound of
ii-«rT> p * J c ' • L- oxiniuriatic

made by Mr Bavy of a graseous compound of oxmiuriatic gas and oxije*,

gas and oxigen. I stated the method of procuring it, and
the property which it has of converting carboni* oxide into
carbonic acid. Mr. Murray appears to think very lightly
of this compound. But I can assure this gentleman,
** notwithstanding it is pro'ured (as he justly remarks)
from the same materials as oxi muriatic gas, and by a pro-
cess apparently not much different from that which is
usually employed,'* that Mr. Davy has found it to possess its sin^lar
very different properties. Copper leaf, arsenic, and the iropertics.
common metals, for instance, which instantlj^ in0ame in
oximuiiatic gas, remain untarnished in this gas. And,
what is extraordinary, it is oxigen in union which prevents
the combustion of the metals from taking place; for when
the combination Jsjbroken by nitrous gas, or a gentle heat,
the oxi muriatic gas, set fr^e, acts as usual. The decompo<^
sition too of this gas by heat is so rapid, that it produces a
loud explosion ; and, if the quantity it> Mrge, a dangerous
one: and it is a v/gry singular circumstance, that it is at-
tended with the evolution of heat, and even of light, not-
withstanding there is a very considerable increase of volume.
Mr. Murray may have remarked tiie difference of colour
between common oximuriatic gas and the gas fioin oxirau-
riate of potash; it is owing to an admixture of the newly
discovered gas. When this gentleman learns, that the pure
gas contams about half its volu! e of oxigen, he will pro-^
bably no longer doubt, that it may bp able to convert car-
bonic oxjde into carbonic acid ; and sincp oxigen united to
oximuriatic gas deprives the latter of all those properties,
which it w.is supposed to owe to loosely combined oxigen, gj^^^f, j^^^k
he will probably adopt the new idea, that oximuriatic gas r

is a simple body. But if on the contrary he should still
prefer the old hypothe»ib---the consequence is inevitable—.

44 O^ THI HTfEltOXIMrRIATE OF POTABlli

he must account for mariatic acid being a supporter of
combustion when combined with a stng/e proportion of
oxigen, and a nonsupporter when combined with a double
proportion, and for a variety of oth€r aworaalie*, which it
is needless to mention.

1 am> Sir, with great respect.

Your humble servant,

J. DAW.
London, March the 15/A, 1811.

Til.

An Attempt to answer the Queries proposed by F. D. in
the Journal for April last : />y William Crane, JSjj.
F. R, M. 5. Edinburgh

To Mr. T^ICHOLSON.
SIR,

Ouejtionscn jt\. Correspondent, in your Journal for April, has in a

o/h p€KaU*° P^P^'^ *>" ^^^ production of hyperoxiaiuriate of potash &c,

muriate of pointed out some errours, into which Mr. Davy has fallen,

potash. jjj accounting for the formation of muriate and hyperoxi-

moriate of potash ; also respecting the formation of muriate

of ammonia and oxide of tin, on the addition of water and

ammonia to the fuming liquor of Libavius.

He observes, that, " when the oximuriatic acid comes
into contact with the oxide of potassium, we must suppose,
that part of it from superior affinity displaces part of the
oxigen, and combines with the potassium'*. He then pro-
poses the following questions :— " How shall we in the first
place account for this partial action? If a superior affinity
exist between part of the oximuriatic acid and part of the
potassium; how is it, that it does not subsist between the
whole? How is it, that the whole oxigen of the potash i»
not set free, and the combination consist of muriate of potash
Partial r^ecom- «nly ?" In answer to these question*; it may be observed,
positions take that there are many phenomena in chemistry, where a partial
aikirf? *^ *' decoipposition only takes place, as has been noticed and
explained by Bertholiet in his Chemical Statics.

His

0» THE HYPBaOXiMURIATB OF POTASB*^ ^

HU next questions are :— «" But what becomes of that per- Farther ques-

tion of oxigen which is liberated? Does it unite with the**®"^*

remainder of the oximuriatic acid, and so united, do they

combine with the remaining oxide of potassium ? or, is it

attracted by the already saturated oxide, and that too in the

face of a superior affinity ?" According to the explanation Answer oa the

which has been given by Mr. Davy, these objections cer- supposjuoa

. that poiassiun

tainly present themselves; but if we agree with Mr. Mur- ,3 united with

ray*, that potassium is the basis of the alkali united with ^'v^ogen,
hidrogen, a circumstance which I think that able chemist
has proved from the experiments he has made, and from those
of Gay-Lussac and Thenard, they are in a great measure re-
moved. When hidrogen unites by combubtion with oxigeo,
the product which is obtained is invariably water, which
Mr. Davy supposes to be the union ot these gasses in k neu-
tralized state. Hence as the union of potassium with oxi-
gen is always attended with combustion, there is great pro-
ba)>ility, that the hidrogen of the potassium unites with
oxigen and forms water, and we obtain, instead of an oxide
of potassium, as has bee • supposed, a hydrate; or pure
alkali is the unknown base combined with water. That *

thiols the case is also probable, from the very strong at-
traction alkali has for its water of crystallization, from
which both Mr. Davy and Mr. Berthollet say it cannot be
entirely freed at a very high temperature : after it has beeii
freed from the water it holds in superabundance, I would
suppose, it then requires the aid of a chemical agent, pow-
erful enough to decompose the water it still retains, thus
liberating the oxigen, whilst the hidrogen remains united to '

the unknown base, forming potassium. Agiiu, as oximuri-
atic acid can unite with water, it requires no twisting of
theory to suppose, that the hyperoximuriate of potash is a'
triple compound consisting of oximuriatic acid, water, and
the unknown base, having, perhaps, by the combined affinity
of the water and this base an excess of oximuriatic acrd^
and of course no evolution of gas would take place. This
opinion might be extended a little farther, and .we may
account for the disengagement of oxigen from the liyper^

• See Mr. Murray*s paper, Number for Apiil.

oximurlafc

40

OW TBB HYPEtOXtMtJRIATE OF POTASIt.

tvro acids com
ing over,

oXimiiriate of potash upon the application of heat, by the
combined affinity of the unknown base and oximuriaticacid
for hidn^gcnbein}^ enabled to overcome, by the aid of heat,
the affinity of the oxiijjen for the hidrogen, which neither of'
them can etfect separately,
Ctomposttion His next observation is, that, as muriate of potash is a
fflur'uter^ compound of muriatic acid and potash. " We must now
suppose, that, when the oximuriatic acid first enters the
solution of potash, part of it attracts from the water of the
solution, a portion of hidroj^en ; and, being thus clianged
to muriatic acid, combines with the pot'ish to form muriate
of potash. The oxigen thus liberated unites to the other
portion of the oximuriatic acid and the hyperoximuriate of
potash is formed," which, he says, is a direct contradiction
to the theory advanced to account for the liberation^f oxi-
muriatic acid in the retort,
o^lngtothe To account for the formation of the muriate of potash,
there can be no occasion to have recourse to the decomposi-
tion of the water; for, as murintic acid is extremely volatile,
and as the action of the oxide of manganese isnot instanta-
neous; it is evident, that part of the muriatic acid will rise
and pass over with the oximuriatic acid, particularly in the
first stages of the process, and hence we find both the mu-
riate and oxi muriate of potash.
Decomposi- Mr. Davy, in accounting for the production of \fater

fimin^ li^^uor ^^'^^'" muriatic acid is parsed over litharge, says, it arises
Qf LibiTius. f\-om the superior affinity, which exists between the oxi-
muriatic acid and the lead, and the subsequent union of
the hidrogen of the one and the oxigen of the other. Next,
be accounts for the oxide of tin and muriate of ammouia,
obtained by ammonia upon the addition of water to the
fuming liquor of Libavius, as owing to the superior affi-
nity between the oximuriatic acid and the hidrogen. Now
your correspondent justly observes, that, *' in the first place,
water is composed because the affinity of oximuriatic acid
for a metal is greater than the quiescent affinities, taken to**
gether, of oximuriatic acid for hidrogen and the metal for
oxigen ; and, in the second, water is decomposed because the
affinity of oximuriatic acid for a metal is less than the now
.divellent affinities of oximuriatic acid for hidrogen and the

metal

EXPERIMENTS ON ALLAN ITE. 47

tnetal for oxigen". Supposing the compositions of the wa-
ter in the iirsst instance to take place according to Mr.
Davy*s views, then, in the second, the oxirauriatic acid
is attracted from the tin by the ammonia, at the same time
it attracts, in its turn, the hidrogen of the water; and as by
the attraction of the ammonia the affinity between the oxi-
muriatic acid and ^m is weakened, the tin by this beini^
enabled to attract the oxigen of the water, and thepximuri-
atit acid attracting the hidrogen, the water is decomposed,
and the oxide of tik and muriate of ammonia are formed.

I am, Sir,

Your humble servant,

Mdinbtirgh, April theQth, W. CRANE.

1811.

VIII. •*

Mxperiments on Allanite, a new Mineral from Greenland^
by Thomas Thomson, M, 1). R R. S. E. Fellow of the
Imperial C/iirurgo-Medical Academy of Petersburg L*

BOUT three years ago, a Danish vesself vvas brought Collection of

into Leith as a prize. Among other articles, she contained ["'"frals in a
. " Danish prize.

a Sinai! collection of minerals, which were purchased by

Thomas Allan, Esq., and Colonel Tmrle, both members of
this society. The country from which these minerals had
been brought was not known for certain ; but as the collec-
tion abounded in cryolite, it was conjectured, with very con-
siderable probability, that they had been collected in Green-
land.

Among the remarkable minerals in this collection there One of -these
was one, which, from its correspondence with gadolinite, as -"PPJ^sed^to be
described in the different mineralogical works, particularly
attracted the attention of Mr. Allan. Confirmed ia the
idea of its being a variety of that mineral by the opinion of

♦ From the Transactions of the Royal Society of Edinburgh. <

•f- Der Fruhling, Captain Jacob Ketelson, capturad on her passage from
)cel«ad to Copenhaj;en.

Count.

4$ tiXPERIMENTS ON ALLAN ITE.

Count Bournon, added to some experiments made by Dr.
Wollaston, he was induced to give the description, which
has since been published in a preceding part of the present
volume.

About a year ago, Mr. Allan, who has greatly distin-
guished himself by his ardent zeal for the progress of mi-
neralogy in all its branches, favoured me with some speci-
mens of this curious mineral, and requested me to examine
its composition ; a request which I agreed to with pleasure,
because I expected to obtain from it a quantity of y//na, an
earth which I had been long anxious to examine, but had not
been able to procure a sufficient quantity of the Swedish
gadolinite for my purpose. The object of this paper is to
communicate the result of my experiments to the Royal
Spciety; experiments which cannot appear with such pro-
priety any where hs in their transactions, as they already
contain a paper by Mr, Allan on the mineral in question.
De«cnptioa of Sect. 1. I am fortunately enabled to give a fuller and
more accurate description of this mineral than that which
formerly appeared, Mr. Allan having since that time dis-
covered an additional quantity of it, among which he not
only found fresher and better characterised fragments, but
also some entire crystals. In its composition it approaches
most nearly to cerite; but it differs from it so much in its
external characters, that it must be considered as a distinct
species. X i^ave therefore taken the liberty to give it the
name of Allanite, in honour of Mr. Allan, to whom we are
in reality indebted for the discovery of its peculiar nature.

Allanite occurs massive and disseminated, in irregular
masses, mixed with black mica and felspar ; also crystallised ;
the varieties observed are,

1. A four-sided oblique prism, measuring 117* and 63*.

2. A six-sided prism, acuminated with pyramids of four
udes, set on the two adjoining opposite planes. These last
are so minute as to be ijicapable of measurement. But, as
nearly us the eye can dtterinine, the form resembles fig, 1,
PI. H; the prism of which has two right angles, and four
measuring 135''.

3. A flat prism, with the acute angle of 63° replaced by
ODeplane^ and terminated by an acumination, having three

principal

EXPF.RIMENTS ON ALLANITt. 49

principal facettes set on the larger lateral planes, with wliich
the centre one measures 125° and 55**. Of this specimen an
engraving is given in the annexed plate, fig, 2.

Specific gravity, arcor<ling to my experiments, 3*533.
The specimen appears to be nearly, though not absolutely,
pure. This substaice, however, is so very much mixed "' *

with mica, that no reliance cun be placed on any of the
trials which have been made. Count Bournon, surprised
at the low specific gravity noted by Mr. Allan, which was
3*480, broke down one of the specimens which had been
sent him, in order to procure the substance in the purest
state possible, and the result of four experiments was as
follows. 4*001

3*797
3-654
3*119
In a subsequent experiment of Mr. Allan's, he found it
3-6()5. From these it appears, that the substance is not ia
a pure state. Its colour is so entirely the same with the
mica, with which it is accompanied, that it is only by mecha*
iiical attrition that they can be separated.

Colour, brownish-black.

External lustre, dull; internal, shining and resinour, ;; .cwV

slightly inclining to metallic. ^^'

Fracture, small conchoidal.

Fragments, indeterminate, sharp-edgcd.

Opuke.

Semihard in a high degree. Does not scratch quartz or
felspar, but scratches hornblende ai^d crown glass.

Brittle.

Easily frangible. /

Vowder, dark greenish-gray.

Betore the blowpipe it froths, and melts imperfectly into
a broivn scoria.

Gelatinises in nitric acid. Ia a strong red heat it loset
3*98 ;>tr cent of its weight.

SecU 2. My first experiaients were made on the supposi- Experimsnu
tion, that the mineral was a variety of gadolinite, and were ^»*^<^*^fta.'" '*•
pretty much la the style of those previously made on that *^**"*^*""''"*
substance by Ekeberg, Klaproth, and Vauquelin.

I. 100 grains of the mineral, previously reduced to a fine silex.

Vol. XXIX,— May, 181 u h • p»wdtr

40

XIumuM.

Metallic ox-

til

EXPlfRINENTS aN ILLANITS; '

pfiwd«r in an agate tnoriar, were digested repeatedly on t
f^nd bath ia muriatic acid, till the liquid ceased to have
any a6iion on it. The undissolved residue was silica, mixed
with some fragments of mica. When heated to redness, it
weighed 33*4 j^rains.

2. The muriatic acid solution was evaporated almost t»
dryness, to get rid of the excess of acid, dissolved in a laroje
quantity of water,, mixed with a considerahle excess of car-
bonate of ammonia, and boiled for a few minutes. By this
treatment, the whole contents of the mineral were precipi-
tated in the state of a yellowish j)0wdt'r, which was sepa-
rated by the filter, and boiled, while still moist, in potash
lie. A small portion of it only was dissolved. The potash
lie was separated from the undissolved portion by the tiltre,
and inixed with a solution of sal ammoniac, by raeans of
which a white powder precipitated from it. This white
matter, being heated to redness, weighed 7*9 grains. It
was digested in sulphuric acid, but 3*76 grains refused to
dissolve. This portion pobsessed the properties of silica,
iThe dissolved portion, being mixed with a few drops of sul-
phate of potarih, shot into crystals of alum. It was therefore
alumina, and amounted to 414 grains.

3. The yellow matter, which refused to dissolve in the
potash lie, was mixed with nitric acid. An effervescence
took place, but the licjnid remained muddy, till it was ex^
posed to heat, when a clear reddish-brown solution was ef^
fectcd. This solution was evaporated to dryness, and kept
for a few minutes in the temperature of about 400**, to per-
oxidize the iron, and render it insoluble. A sufficient quao-
tity of water was then poured on it, and digested on it for
half an hour, on the sand bath. The whole was then
thrown upon a filter. The dark red tnatter,"which re-
niained on the filter, was drenched in oil, and heated to red-
ness, in a covered crucible. It was then black, and at-
tracted by the magnet; but had not exactly the appear-
ance of oxide of iron. It weighed 42i*4 graiiiS,

4. The liquid, whicb passed through the filter, had not
the sweet taste which I expected, but a slightly bitter onV,
siniilar to a weak solution of nitrate of lime. Hence it was
clear* that no yttria was present, as there ought to have

tXPERlMENtS ON ALLANltt.

Vl

teen, had the mineral contained that torth« This liquid
being mixed with carbonate of ammonia, a white powder
precipitated, which, after being dried in a red heat, weighed
17 grains. It dissolved in acids with effervescence; the
solution was precipitated white by oxalate of ammonia, but
not by pure ammonia. When dissolved in sulphuric acid,
"ind evaporatt'd to dryness, a light matter remained, taste-
1fe8«, and hardly soluble in water. These properties indi-
cate carbonate of iime. Now, 17 grams of carbonate of
lime are equivalent to about 9*23 grains of lime.

5» From the preceding analysis, supposing it accurate, it Deductions,
followed, that the mineral was composed of

Silira, •..•• 37*l6

Lime, ••• 9*23

Alumina, •••••• 4-14

Oxideofiron, • ••...• 4240

Volatile matter, ••• 3*98

96-91
Loss, •.... .••••••••«• 3-09

lOU'OO ^

But the appearance of the supposed oxide of iron induced The oxide ex-
me to suspect, that it did not consist wholly of that metal. *niin«d.
I thought it even conceivable, that the yttria, which the
mineral contained, might have been rendered insoluble by
the application of too much heat, and might have beea ,

concealed by the iron, with which it was mixed. A number
of experiments, which it is needless to specify, soon con- '
vinced me, that, beside iron, there was likewise another sub-
stance present, which possessed properties different from
any that I had been in the habit of examining. It possess-
ed one property at least in common with yttria; its solu-
tion in acids had a sweet taste ; but few of its other proper-?
ties had any resemblance to those which the chemists, to
whom we are indebted for our knowledge of yttria, have
particularised. But as I had never myself made any expe-
fiments on yttria, I was rather at a loss what conclusion
to draw. From this uncertainty I was relieved by Mr.
Allan, «ho had tht ^odoess to give me a small fragment of
£% ^adoliuitc.

godoHnite, which had been reicived directly from Mr*
Ekeberg. From this [ extracted about 10 grain* of yttria;
and upon comparing its properties with those of the sub-
stance in quetitiou, I found them quite different. Con-
▼inced by these experiments, that the mineral contained no
yttria, but that one of its constituents was a substance with
which I was still unacquainted, I had recourse to the fol-
lowing mode of analysis, in order to obtain this substance in
a pure state.
Analysis. ^^^^' ^^^' '• ^^^ grains of the mineral, previously reduced

ton tine powder, were digested in hot nitric acid, till nothing
SUex. more could be dissolved. The undissolved residue, which

was silica, mixed with some scales of mica, weighed, after
being heated to redness, 35'4 grains.
Oxidtoftron. 2. The nitric acid solution was transparent, and of a light
brown colour. AVhen strongly concentrated by evaporation,
to get rid of the excess of acid, and set aside in an open cap-
sule, it concreted into a whitish solid matter, consisting
chiefly of soft crystals, nearly colourless, having only a slight
tinge of yellow. These crystals, being left exposed to the
air, became gradually moist, but did not speedily deli*
quesce. The whole was therefore dissolved in water, and
the excess of acid, which was still present, carefully neu-
tralised with ammonia. By this treatment the solution ac-
quired a much deeper brown colour; but it still continued
transparent. Succinate of ammonia was then dropped in
"with caution. A copious reddish-brown precipitate fell,
which being washed, dried, and heated to redness in a
covered crucible, weighed 25*4 grains. It possessed all the
characters of black oxide of iron. For it was attracted by
the magnet, completely soluble in muriatic acid, and the
solution was not precipitated by oxalate of ammonia.
Another preci- 31. The liquid being still of a brown colour, I conceived
pi ate thrown ,j^ ^^^ ^^ ^^ completely free from iron. On this account, an
additional quantity of succinate of ammonia was added.
A new precipitate fell ; but instead of the dark reddish-
brown colour, wliich characterises succinate of iron, it hod n
beautiful flesh-red colour, which it retained after beinp
dried in the open air. W hen heated to redness in u covered

crucible.

EXrERlMENTS ON ALLAKITe. ^Jjjj^

crucible, it became black, and had some resemblance ^o
gunpowder. It we.ghed 7*-2 ^rain^!.

4. This substance attracted my peculiar attention, ia con-Thwexa«
sequence of its appearauce. 1 found it to possess the fol*« "^" *
lowing characters :

a. It was tasteless, and not in the least attracted by the It&charactctk
inajj;net, except a few atoms, which were easily separated
from the rest.

h. It was insoluble in water, and not sensibly acted on whea
Wiled in sulphuric, nitric, muriatic, or nitro-niuriatic acid.
-^^ c. Before the blowpipe it melted with borax and micro*
cosmic salt, and formed witb both a colourlesi bead. With
carbonate of soda it formed a dark-red opake bead.

d. When heated to redness with potash, and digested in
water, snuff-coloured florks remained undissolved, which
gradnully subsided to the bottom.. The liquid being sepa-
rated, and examined, was found to contain nothing but
potash. When muriatic acid was poured upon the snufF«
coloured flocks, a slight effervescence took place, and when
heat was applied, the whole dissolved. The solution was »
transparent, and of a yellow colonr, with a slight tint of
green. When evaporated to dryness, to get rid of the
excess of acid, a beautiful yellow matter gradually sepa*
rated. Waten boiled upon this matter dissolved the whole.
The taste of the solution was astringent, with a slight
metallic favour, by no means unpleasant, and no sweetness

was perceptible.

e. A poi*tion of the black powder being exposed to a red
heat for an hour, in an open crucible, became reddish-
brown, and lost somewhat of its weight. In this altered
state, it was soluble by meajis of heat, though with diffi?-
culty, both in nitric and sulphuric acids. The solutions
had a reddish-brown colour, a slight metallic astringent;
taste, but no sweetness.

/. The solution of this matter in nitric and muriatic acid, Action of ro.
when examined by reagents, exhibited the followiiig pheno- '»?^"!^ "" *<*
nomena:

(I.) With prussiate of potash, it threw down » white pre^
cipitate in flocks. It soon subsided ; readily dissolved
in nitric acid; the solution was green.

M BXFERIMBNTS OIT ALlAVITE.

(r.) Prussjate of mercury. A light yellow precipitate, 8e«

luble in nitric acid.
(3.) Infusion of nut gallb. No change.
(4.) Gallic acid. No change,
(5.) Oxalate of ammonia. No change.
• (6.) Tartrate of potash. No change

(7.) Phosphate of soda. No change.
(8.) Hydrosulphuret of ammonia. Copious black flocks.
Liquor remains trnneparent.
; (9.) Arseniate of potash. A white precipitate.

- (1 0.) Potash. • \ Copious yellow-coloured

(H.) Carbonate of soda. > flocks ; readily distiolved in

(12.) Carbonate of ammoria* J nitric acid.
(13.) Succinate of ammonia. A white precipitate.
(14) Benzoatc of potash. A white precipitate.
(15.) A plate of zinc, being put into the solution in muriatic
acid, became black, and threw down a black powder,
which was insoluble in sulphuric, nitric, muriatic, nitro*
muriatic, acetic, and phohphoric acids, in every tempera*
ture, whether tbe&e acids were concentrated or diluted.
(l6.) A plate of tin, put into the nitric solution, occasioned
- ..-?)4&o change.

i-fl/y.) A portion being epclosed in a charcoal crucible, ant}
• x,€xpQsed for an hour to the heat of a forge, wab not re^
duced to a metallic button^ nor could any trace of it bij
detected when the crucible was examined,
Theie proper- These properties were all that the small quantity of the
eTthose of e- "^*^^**"^ ^" "*y po^^esi^ion enabled me to ascertain. They un-
rium, equivocally point out a metallic oxide. Upon comparing

them with the properties of all the metallic oxides known,
none will \^t found with which this matter exactly agrees.
Cerium is the metal, the oxides of which approach the
n'earest. The colour \» nearly the same, and botji are pre-
cipitated white by prussiate of potash, succinate of am monia,
but w|th some and bpn^oi^te of potash. But, in other respects, the two
<iinereace». - j^^tanpes diifer entirely. Oxide of cerium is precipitated
white by oxalate of ammonia and lartrate of potash; our
oxide is not precipitated at all: Qxide of cerium is pre-
cipitated white by hydrosulphuret of ammonia; while our
oxide is precipitated black : Oxide of cet'ium 19 not precipi-
tated

£ZPERIM£NTB ON ALLANIT£. M

fated by zinc, while our oxi<I« is thrown down blacW.^ There
are other differences between the two, but those which i
have just mentioned are the most striking.

These properties induced me to consider the substance Suppose4 a
which 1 had obtained from the Greenland mineral as (he "^^ '"*^*'
oxide of a metal hitherto unknown; and 1 proposed to dis-
tinguish it by the name oi'junonium.

In the experiments above detailed, 1 had expended almost Junonium.
all the oxide of junonium which I had in my possession, J^

taking it for granted, that I could easily procure more df it
from the Greenland mineral. But, soon after, I was in»
formed by Mr. WoUaston, to whom I had sent a specimen
of the mineral, that he had not been able to obtain any of
my supposed junonium in his trials. This induced me to
repeat the analysis no less than three times, and in neither
case was I able to procure any more of the substance, which I
described above. Thus, it has been out of my power, to
verify the preceding details, and to put the existence of a
new metal in the mineral beyond dotibt. At the same time
I may be allowed to say, that the above experiments v/ere »miy. ;m'. r >
made with every possible attention on my part, and most of ; '

them were repeated, at least a dozen time?. I have no ,

^^oubt rayselfiof their accuracy ; butthink that the existence of
a new metal can hardly be admitted, without stronger proofs
than the solitary analysis which I have performed.

5. The liquid, thus freed from iron and junonium, was Alumine.
supersaturated vith pure ammonia. A grayish white gela-
tinous matter precipitated. It was separated by the filter,

and became gradually darker coloured when drying. This
matter, after being exposed to a red heat, weighed about 38
grains. When boiled in potash lie, 4*1 grains were dis-
solved, of a substance which, separated in the usual way,
,exhibited the properties of alumina.

6. The remaining 33*9 grains were again dissolved in An oxide,
muriatic acid, and precipitated by pure ammonia. The
precipitate was separated by the filter, and allowed to dry
flpoutaneously in the open air. It assumed an appearance'
very much resembling gum arabic, being semitransparent,
and of a brown colour. When dried upon the sand-bath,
it became very dark brown> broke with a vitreous fracture,
and still retained a smaU degree of transparency. It was

tasteless.

■ k^^.^^^iH -^^

5§ tiltPEBlXENTS 0» AtlANtTI.

• tastefj^/felt gritty between the teeth, and was easily redace<l
to powder. It effervesced in sulphuric, nitric, inuriutic, and
acetic acids, and a solution oF it was effected in each by
^ • means of heat, though not without considerable difficulty.

The solotions had an i:uster^, and slightly sweetish taste*
When examined by reagents, they exhibited the following
properties :

examined by (l.) Prussiate of potash. A white precipitate.

rtrfgtuts, j2.) Oxalate t>f ammonia, A white precipitate.

(3.) Tartrate of potash, A white precipitate.

(4.) Hydrosulphuiet of potash. A white precipitate.

(5.) Phosphate of soda. A white precipita.e.

(6.) Arseniate of potash. A white precipitate.

(7.) Potash and its carbon-ate. A white precipitate,

(8.) Carbonate of ammonia. A white precipitate.

(9.) Ammonia. A white gelatinous precipitate.

(10.) A plate of zinc. No change.

appealed to These properties indicated oxide.of cerium. I was there-

differ m some I'Qj.g (^^gposed to consider the substance which I had obtained
respects from ^

that of ce- as oxid^ of cerium. But on perusing the accounts of that
rium; substance, given by the celebrated chemists to whose la-

bours we are indebted for pur knowledge of it, there were
several circumstances of ambiguity which occurred. My
powder was dissolved in acids with much greater difficulty
than appeared to be the case with oxide of cerium. The
colour of my oxide, when obtained from oxalate, by ex-
posing it to a red heat, was much lighter, and more inclined
to. yellow, than the oxide of cerium.

In this uncertainty. Dr. WoUaston, to whom I communi-

caied my difficulties, offered to send me down a specimen

' of the mineral called cerite, that I might extract from it

real oxide of cerium, and compare my oxide with it. This

butlhii owing offer I thankfully accepted *; and upon comparing the pro-

10 the method pe|.tiesof my oxjde with those of oxide of cerium, extracted

was procured, from cerite, I was fully satisfied that they were identical. The

more

♦ The specimen of cerite, which I analysed, was so much mixed with
actonolite, that the statement of the results which I obuined canno^

be

EXPERlUETiTI ON ILLlNITfi. SJ

more difBcuU solubility of mine was owing to the methoa f*
had employed to procure it, and to the strong heat to which
I had subjected it; whereas the oxide of cerium from cerite
had been examined in the state of carbonate.

7. In the many experiments made upon this powder, and Some paaiie«»
up«Ki oxide of cerium from cerite, i repeated everything that J'^pfife^^
had been established by Beizelius and Hisinger, Klaproth noticed,
and Vauquchii, and had an opportunity of obseiving many
particulars, which they have not nr.ticed. It may be worth
while, therefore, without repeating the details of there
chemists, to mention a few circumstances, which wilLvbe
found useful in examining this hitherto scarce oxide, i ^ 4^'*

a. The precipitate occasioned by the oxalate of ammoiiia
is at first in white flocks, not unlike that of muriate of sil-
ver, but it soon assumes a pulverulent form. It dissolves
readily in nitric acid, without the assistance of heat. The '

same remark applies to the precipitate thrown down by the
tartrate of potash. But tartrate of cerium is much more
soluble in acids than the oxalate.

6. The solution of cerium in acetic acid is precipitated
gray by infusion of nut-galls. Cerium is precipitated like-
wise by the same reagent from other acids, provided the so-
lution contains no excess of acid. This fact was first observed
l?y Dr. Wpllaston, who communicated it to me last sum'*
mer. 1 immediately repeated his experimei)ts with success.

c. Cerium is not precipitated from its solutions in acids
by a plate of ziuc. In some cases, indeed, I have obtained
a yellowish-'ed powder, which was thrown down very slowly.
But it proved, on examination, to consist almost entirely
of red oxide of iron, and of course only appeared when the
^lutioD of cerium was contaminated with iron.

l^eof much importance. The specific gravity of the specimen was 4* 149,
I fvund it composed as follows :

A white powder, left by muriatic acid, and presumed tq basilica, 47-5

Ked oxide of cerium 44*

Iron , .'1 i .'i', ; , , . 4«

Volatile matter , S^

^^» •••••••••••' • '_^ u,'%^

1000
d. Tho

53 EXrCRIMEKTt OK ALtANITl.

d. The solutions o(' cerium m acids have an astringent
taste, with a p)€rce|ir«bfe 8weemes8> which, however, is dif-
Cpreot from the sw*retn<»s, which some of the solutions of
iron in acids possess.

e. The muriate and sulphate of cerium readily crystal-
lise; but I could not succeed in obtaining crystals of lutrate
of cerium.

Best m«tKod f» The best way of obtaining pure oxide of cerium i»» to

Ae*«at^"* F^cipiUte the solution by oxalate of amuionia, wash the

precipitate well, and expose it to a red heut. The powder

i^tained by this piocess is always red : but it varies very

roach in it::, shade, and in its beauty, according to circnm*

stances. This powder always contains carbonic acid.

Csscntal cha. g, 1 consider the following as tl^ es>rential characters of

"^1^ certutn. The solution Jmss a sweet astringent taste. lti»

precipitated white by prussiate of potash, oxakite of ammo*

liia, tartrate of potash, carbonate of potash, carbonate of

ammonia, succinate of ammonia, benzoate of potash, and

bydrosulphuret of ammonia. The precipitates are redis-

solved by nitric or muriatic acids. Ammonia throws it

down in gelatinous flocks. Zinc dees not precipitate it

at all.

A. The white oxide of cerium, raent'ioned by Hisinger and
Berzelius, and described by Vauquelin, did not present
itself to me in any of my experiments: unless the whito
Hocks precipitated by ammonia from the original solution
fee considered as white oxide. They became brown on dry*
ing, and, when heated to redness, were certainly converted
ioto red oxide.

As cerium, as well as iron, is precipitated by succinate
of ammonia, the preceding method of separating the tv<ro
fiom each other was not unexceptionable. Accordingly,
in some subsequent analyses, 1 separated the cerium by
means of oxalate of ammonia, before 1 precipitated the
' iron. I found, that the proportions obtained by the analysis

above described were so near accuracy, that no material
alteration is necessary.
XI9M, 8. The liquid, thus freed from iron, alumina^ and cerium,

iqeas mixed with carbonate of soda. It precipitated a quan-
tUy of carbonate of lime, which amounted, as before, to

about

ON TBS METALS OF THB ALKALI!*.^ 5^

{. .-r

about 17 grains, indicatinjj 9*2 grains of lime.

From the preceding analysis, which was repeated no lesi
than three times, a diftVrent method being employed in
each, the constituents of allanite are as follows :

Silica ••.... 35'4

Lime 9-2 ^7.7:1

Alumina • 4*1 nite.

Oxide of iron • • • • • • 25*4

Oxide of cerium 33*9

Volatile matter •••• 4*

112-0

1 omit the 7 grains of junonium, because I only detected it
tn one specimen of allanite. The excess of weight in the
preceding numbers is to be ascribed chiefly to the carbonic
acid combined with the oxide of cerium, from which it was
not completely freed by a red heat. I have reason to be-
lieve, too, that the proportion of iron is not quite so much as J^^, ^^^"^ P**"

r> ' , . , . , bably over-

25*5 grains. For, in another analysis, I obtained only 18 rated.

grains, and in a third 20 grains. Some of the cerium was
perhaps precipitated along with ii in the preceding analysis,
and thus its weight was apparently increased.

IX.

Observations on Thre€ Papers of Mr. Davy. By Messrs.
Gay-Lussac ajtd Thekard*.

In the Annales de Chimie for September last are transla- ^ -^ ,
tions of three papers by Mr. Davy, sent to France by that observatjon*
gentleman, and entitled, 1. Observations on the Researches °^ ^^if '^^f
of Messrs. Gay-Lussac and Thenard relative to the Amal- Gay-Lussac
gam furnished by ammonia. 2* Examination of some and Thenard
Observations of Messrs. Gay>Lussac and Thenard on the
Facts respecting the Metals of the Alkalis. 3. Reply to

♦ Abridged from ihe Aiuial. de China, vol. LXXV, p. 290.

Messrs.

60

ON THE METALS Of THfi ALRALIt*

tosweied.

Itttxodoction.

Aivalgam of

iTi>monTa not
actedonby the
»ir or sulpbaric
mcki

A compound
©f ammonia,
hidroiL'en, and
mercury.

Messrs. Ga -Lussac and Thenani's Answer to the Analytr*
cal Researches, kt\ These are followed by Observations
on them by Messrs. Gm> -Lussac and Thenard, some ex*
tracts from . which will no do«bt be acceptable to our
readers; thoui;h a translation of the whole would take up
much room to little purpose, as most of the facts have
come before them in a drflt'rent form. The following is its
exordiutn.

** The observations about to be read are divided into
tKr^e parts. We shall merely relate our mode of viewiug
things, supporting it by rFasons, which we believe to be
preponderant. If by accident any expressions escape us
liable to be misconstrued, we request our readers, and par-*
tiictilarly Mr. Davy, not to do this, v It is our intention,
unquestiopably, to combat some of his opinions, because
we do not always, think with him : but while we combat
them we wish to employ the language suited to truth, and
merit the esteem of the celebrated chemist, whose talents
have justly entitled him to that of all Europe, and more
particularly ours.'*

On the first head these gentlemen say: " we have de*
monstrated, that the amalgam of ammonia has no action
on the air, or on sulphuric acid ; and it is totally impossi*
ble, that it should cover itself in the open air with a white
povrder of carbonate of ammonia." And again:

*♦ In fine, we believe we have fully demonstrated, that
the ammoniacal amalgam is nothing but a compound of
mercury, ammonia, and hidrogen : for Mr. Davy opposes
nothing to us, but that it is impossible to dry this amalgara
thoroughly with blotting paper ; and that the water, which
covers it, combines with the ammonium, and reforms am-
monia. But we know very well, that it is difficult to dry
the surface ol this amalgam with paper: and accordingly
we take only the centre, after- having cooled it to zero [32°],
to increase ils consistency ; we introduce it into a very dry
jar with very dry mercury; and immediately the amalgam
decomposing gives out ammoniacal and hidrogen gas. Cer-
tainly this experiment is unobjectionable.

" However, as this experiment has not convinced Mr,
Davy; and as perhaps ht*-\vill tell us, that there is a little

wate?

tON THE METALS OF THE ALKALIS. ^ 6|

Water (which however cannot be) in the centre of this amal-
gam, we will relate another, to which we think he cannot
reply« It is as follows,

•* After having made a liquid amalgam of potassium, we Expenmentte
poured it into a large cupel of moistened sal ammoniac* P'^'^^^
and obtained immediately, by the process for which we are
indebted to Mr. Davy, a very bulky and very consistent
compound of potassium and ammoniacal amalgam. Then,
having remor&d with a knife all the upper part, we took
out the interior parts with a very dry iron spoon, and imme-
mediately put them into a tube almost full of mercury,
which had been previously boiled. Afterward, having closed
this tube, which was thus filled with mercury and the com-
pound of ammoniacal amalgam with potassium, with a very
dry stopple, we inverted it in mercury also well dried. The
amalgam rose above the mercury, and was almost imme-
diately decomposed, particularly by means of a slight agi-
tation. But, in proportion as the decomposition went on, a
pretty considerable quantity of gas was extricated ; and this
gas was always found to be a mixture of ammoniacal and hi-
drogen gas, in the proportion nearly of 2*5 to 1. Now will
it be said, that the mercury or our vessels were humid ? We
can prove they were not; for, on pouring into them* aa
amalgam of potassium, instead of a compound of potassium
and ammoniacal amalgam, no gas was evolved. Or will it
be said, that the interior of the ammoniacal amalgam with . *

potassium contained a small quantity of water ? But this V

is impossible, since water and potassium cannot exist to-
gether. Or, finally, will it be said, that we could not ac-
curately remove with a knife the external portions of th^ .
compound of ammoniacal amalgam with potassium ? But
the experiment is so easily performed, that it can never
fail.

«* Thus the slightest objection cannot be made to this $««•***

experiment, and it must be conclusive, even in the eyes of
Mr. Davy. Besides, the result is easily understood: it is. The result ex-
the potassium, combining with a very large quantity of P^*^"^»
mercury, is so disseminated, that it can no longer act with
sufficient force on the ammonia and hidrogen to unite
th^m ; so that the ammoniacal amalgam of potassium finds

itself

C2 OW THE METAL» OF THE llKALlg.

Hself in this case subjected to the same laws, as that whicti
is formed solely, of mercury, ammonia, and hidrogen,
and which cannot exist, except under the electric influ-
ence.
Lightness of ** If Mr. Davy admit, that the ammoniacal amalgam i§
tkeamaleam ^ comj.'ound of mercury, ammonia, and hidrogen, he must
admit also our explanation of the phenomena exhibited by
its formation, or of the cause of its bein^ five or six times
as bulky as the mercury it contains. This explanation ia
perfectly natural. In fact, since the hidrogen and ammo*
tiia are scarcely more condensed in this amalgam, than they
are in the state of gas, which is proved by the facility with
vhich they escape from it, they cannot but considerably
diminish the specific gravity of the mercury. The pro»
perty that mercury has of being about 34000 times as heavy
as hidrogen gas; and that which gold has of losing it»
lustre and ductility, and becoming soluble in all the acids,
by the addition of a few hundredths of oxigen gas, are fact*
as extraordinary."

Under the 2d head the French chemists observe :
Solid hydruret ** Mr. Davy says, that he could never succeed in com-
•f potassittin, |,*u^j,^g hidrogen gas with potassium, so as to form the solid
hydruret of potassium; which we made known in 1808,
No. 144 of the Moniteur, &c. ; and on the preparation of
which we gave fome fresh information in No. 330 of the
Mr. Dary's re- Bibliothkqiie britannique, in September, I8O9. He imagines,
marks ^^^^ -^^ ^^^ experiments we paid no attention either to the

solution of potassium in hidrogen gas; a solution, which,
according to him, occasioning probably a condensation of
this gas, might have led us into an errour; or to the influ-
ence of the metal on glass; or to the circumstance, that,
from his observations, very small quautities of air or water
give rise to a grayish powder, similar to what we announce
answered. IIS the hydruret of potassium. Our answer to all these ob-
servations shall be very simple. Let a certain quantity of
potassium, as was said. Bib. brit. No. 330, p. 47, and of
very dry and very pure hidrogen gas, be heated in a curved
glass jar, thoroughly freed from air and water, and with its
extremity immersed in water, the mercury will goon be seea
to ascend rapidly in the jar, ayid at tlie expiratJon 6f a cer-

taia

ON THB METALS OF THE ALKALIS. $$

tain time to be nearly stationary. At this period let the
gaseous residuum be measured, and suppoi^f it to be equal,
for instance, to two thirds of the volume of hidrogen em»
ployed, it will be concluded, that one third of the hidroj^en
has l)een absorbed by the potassium. And, in fact, it may
be expelled from it immediately, by heating the potassium
snffitiently in the same jar in which the experiment has
been made, and which is then full of mercury.

"Thus we find, that potassium absorbs a quantity of
hidroijen, which is equivalent nearly tp a fotirth of what it
gives out with water. We have repeated this experiment a
great number of times,, the result has always been the same.
It is certain then, that a solid hydruret of potassium exists. ^ ^ ^

The properties of this hydruret may be seen in the Bib, brit,
as above quoted.*"

"Mr. Davy says, that potassium absorbs more ammonia- Potanlum
cal gas dried by lime, than of common ammoniacal gas, in ^^^ ^o,^diy
the proportion of id to 12*5. We have always observed on ammoniaca
the contrary, that the absorption of these two gasses is per- moist ^'^
ceptibly the same with an equal quantity of potassium, if
the temperature be the same; as we have already shown in
the Bib. brit. What Mr. Davy considers as potash is
already, according to us, an ammoniuret.

** Mr. Davy says, that i he ammoniuret. made with »n)mo- Ammoniuret
piacal gas and potassium, does not give out, as we have ad« g,y^Qu\'*^™^
vanced, the 0-6 of ammoniacal gas it contains; narr;t'ly. 0*4 ''rj^nionia un-
npt decora posedj^^nd 0-2 decomposed; or at least that thetie ^^™^'"**^

♦ ** !t is iu tlie foirn of a gray powder, which has not a metatHc ap- Properties of
pearancc. Ii effervesc s briskly with water, and gives out abdut one ^^^ hidruret of
fourth more of hidrofeu, than the metal it contains is capable of giving P**'**"^'""*-
out. Placed in contac; with mercury in the cold, it is giadually decom-
posed j, an amalgam of this metal is formed, and all the hidroeen, to
which it owed its pulverulent state, is evol-e-?. if heated, its detomr
position by niercurj is almost instantaneous, and no more hidrogen gas Lr
evolved than wl«en cold, in fine, hea'ed to an obscure red, it resumes
the metallic anpearance, and also evolves all the hidrogen, ttthich the " * ♦%

metal had absorbed." Ann. de Chim. vol. LXXII,p 266. . -i '". \. '^

■f Messrs. GayrLussac and ThenarHsay, in the ]ilace referred to, thatC' * * *'

temperature somewhat elevated expels a great deal of ammonia frv)m the
olive coloured subitarice; and hence th quantity of ammonia absorbed
by the metal is verj variable, according to the temperature employed.

results

ON THE METALS OF THE ALKAUf.

resntU are obtained only so far as there is moisture in thri
vessels employed. On this point we cannot accede to ihe
opinion of Mr. Davy : neither our gasses, nor our mercury,
nor our vessels, contain water; and yet we always obtaia
from this ammoniuret the 0*4 of ammoniac without being
■»* decomposed. This dift'erence between our results and those
of Mr. lyiivy does not depend on water, as he supposes, but
on the high temperature, to which he exposes the ammo-
niuret.'*

Under the 3d head Mesf rs. Gay-Lussac,and Thenard say :
l«!pliOTet and ** On treating the sulphurets and phosphurets of potas-
S^fum^' *^sium with an acid, assisted by heat, as ought to be doxit,
fceated with neither hidrogurelted sulphur, nor hidroguretted phospho-
WMid. ,.yjj^ is formed; and we always obtain even more phosphu-

retted hidrogen,thanis requisite to represent the hidrogen of
the potassium.

*' Mr. Davy says, 1st, on treating the sulphuret of potas-
sium with muriatic acid, he has obtained very variable
quantities of sulphuretted hidrogen gas; and that in gene-
ral less is evolved, than the potassium of this fculphuret
would disengage of hidrogen from water: 2dly, that, on the
contrary, on treating potassium with sulphuretted hidrogen
gas, there is a greater quantity of h.drogen gas set free, than
that which the potassium employed is capable of evolving in
its contact with water.

**We have repeated more than fifty times our experi-
ments on sulphur, sulphuretted hidrogen gas, and potas-
sium : the sulphuret cf potassium has always afforded us by
Acidsa quantity of sulphuretted hidrogen gas, equal in vo-
lume to the i»idrogen, that the potash was capubie of evolv-
ing by its contact with water: and always too, on treating
potiissium with sulphuretted hidrogen gas, we have ob-
tained as much hidrogen gas, as the pofassiu.n would have
yielded with water.

•* We affirm anew, that these results are certain.

Potassium «* Mr. Davy considers it as probable, that, on heating po-

•ulphur. taasium with sulphur, a portion of potassium remains in the

centre of the sulphuret of this metal. It but little sulphur

be employed, this does not take place: still less then can it

when a great deal is used, as is done by Mr* Davy.

••Mr,

OK tHB IliETALS OF THE ALKALIS. ^5

" Mr. Daw savs it is evident* that the method we employ Experiments
, 11- • 1 r o" phosphorut

in our endeavours to show, that his experiments on phospUo- ^nd phosphu-

ru» and phosphuretted hidiogen are not accurate, do not rt^^titi *^i<lfO^
apply to the case he has in contemplation. * They have ^
acted,' he adds, • on the phosphuret of potassium with hot
water, and thus they form phosphate of potash, and a large
quantity of phosphuretted hidiogen gas; whereas, when
strong muriatic acid is employed, the muriate of potassium
is produced, and the oxigen is furnished solely, or princi-
pally te the potassium. We cannot form just conclusions,
unless when the potassium alone is oxided ; and my design
in employing but a small quantity of acid was to oxide this
iubstance alone."

** We shall observe, Ist, that we have treated the phos-
phuret of potassium not with hot water only, but with acids
also ; and that in eVery case we have proved, that more phos-
phuretted hidrogen gas was obtained, than was required to
represent the hidrogen gas, that the potassium of this phos-
phuret was capable of furniihing with water; and that
therefore Mr. Davy has nothing to object to the means we No oxigen ex-
have employed to refute his opinion, or to demonstrate, that ^^^s in mem.
no oxigen exists either in phosphuretted hidrogen, or in
phosphorus.'*

** Mr. Davy accuses us of contradicting ourselves, as we Potassium lit
have said, Mem, d'Arc, vol. II, p. 304, that potassium, when hidrogen from
heated in phosphuretted, sulphuretted, or arsenicated hidro- phosphuretted,
gen, absorbs the phosphorus, sulphur,orarsenic, and a portion h^dro^gen- *
of hidrogen ; and we say. Jour, de Phys. Dec. I8O9, that po-
tassium sets free all the hidrogen of phosphuretted or arseni-
cated hidrogen. In this there is nothing extraordinary. At
first we employed an excess of potassium, and an absorption
of hidrogen took place. But since, particularly when Mr. not oihen;? Ise.
Davy had conchided from his experiments, that sulphfir,
phosphorus, and pho&phu retted and sulphuretted hidrogen,
contain oxigen, having examined anew the action of potas-
sium Oil sulphurette(l, phosphuretted, and arsenicated hidro-
gen gas; and for this having necessarily employed an excess
of gas; we have seen, that, in this case, no portion of the
hidrogen of the phosphuretted or arsenicated hidrogen i» ab-
sorbed. Tns it appears, that we are perfectly consistent;
Vol, XXIX.— May, 1811. ^ '-F 4. s- gjnce

«6

PERSPIRATION OF FRAXlNELlA-

Potassium ab-
sorbs phoNph.
hid. gas vrith>
out flame.

suTph. hid.
with.

Arsenicatcd
hidrogen con-
taiiis oxigen.

Nooxigen in
sulphur or
phosphorus.

Collection of
^Experiments,

since we can at pleasure cause the hiHrogen of these gasse*
to be absorbed or not by the potassium.

" INIr. Davy observes, that we have said potassium ab-
sorbs phosphuretted hidrogen gas with flartie ; while on the
contrary, as he has found, it absorbs it without flame. This
is true, and the mis,take has even occasioned us to make
another, which Mr. Davy does not mention : it has led ur
to say, that potassium absorbs siilphurettfd hidrogen ga»
without the emission of light. The fact is, these two ex-
periments were made at the same time, and one was written
down for the other. This may easily be conceived, for th«5
phenomena are too visible not to be perceived. If we give
this explanation however, it is not to exculpate ourselve*
from the mistake.*'

** Mr. Davy coftn plains of our having said, that, if he
were acquainted "with the action of arsenicated hidros^en gas
on potassium, he would have inferred from it the existence
of oxigen in this gas. We think thfe same still, because we
do not obtain, on treating arsenic with water, a quantity, of
hidrogen gas representing that which potassium is Capable
of giving with water.

'* Mr. Davy could have wished, that we had spoken of
his experiments to demonstrate the existence of hidrogen
in feulphur and phosphorus ; and complains, that we have
only endeavoured to point out errours. ***** But our
only object was to inquire, whether these experiments de-
monstrated tlie existence of oxigen in these two substances:
and, as no one of them proves this, and as the result of all
•re contrary to ours, we conld not but draw inferences frona
them opposite to those of Mr. Davy."

** in a Collection of our Experiments, now in the press,
we shall answer all Mr. Davy's objections, and endeavour to
render him the com pletet>t justice."

Assertion that
?,he bastard dit

X.

Obxermtions respecting the Sensible Perspiration of the Die-'
tnmnus Albus, or Fraxinella, By Mr. Robert Lyall,
Surgeon, ]SL R, P. S. E, Sfe, Communicatedhythe Author.

jl.T has been said, that in calm summer evenings the
dictaninui albuf evolves hidrogen gas, or a highly odorous

inflammable

PERSPIRATION OP FRAXINELLA. gjt

iuflammabk efRuviuin, which explodes when brought into tany emits a«
contact with the flume of a candle ; an opinion that is main- l^,^'"™^ *
tained in the latest botanical publications 1 have seen.

When I first became acquainted with the above notion, Experiment
my curiosity was excited, and I longed for an opportunity ™adeonit.
to miike the experiment, which was not very long denied me.
The result of my observations I shall now relate in order,
that the subject may be more accurately investigated.

I need scarcely premise, that the peduncles, the calyx, Glands on it
the outside of the corolla, and especially the tops of the fi- containing a
laments, and the germen of the dictamnus, are covered with
glands of an oblong fortn, many of them supported on little
pedicles, all of them of a beautiful red colour, and contain*
ing a somewhat viscid fluid.

On the 10th of July, about ten in the evening, the wea- Exp. 1.
ther fine, avid the temperature 66, I commenced my expe-
riments on the dictamnus. By holding a lighted candle at
the bottom of a raceme of flowers, intonsiderable ejcplosi-
ons, or rather a hissing noise was occasioned, accompanied
by light-blue coloured flame, which proceeded along the
course of the peduncles, &c., and ascended even higher than
the top of the stem; a good deal resembling an amusing
experiment sometimes practised in the theatre, and often by
boys, by means of powdered resin and a burning candle, &c.
Immediately after the combustion, the surrounding atmos-
phere became tainted with odoriferous effluvia, exactly si-
milar to what the healthy flowers, thoush much stronger,
emit. July 13, I repeated this experiment, at the same Exp. 2.
hour as before* 'I he evening was fine, but the plants were
wet with the afternoon's rain. Scarcely any noise was pro*
duced ; the experiment not succeeding as before.

At another time 1 brought home a raceme of flowers. Other exneri- "
and after it had stood with its end placed in water for "^®"*5*
two hours, I approached a burning candle to it, and little
explosions followed. 1 replaced the raceme in the water,
and next morning darkened my room, and made the same
experiment, but heard no explosions. Since the 13th of
July, 1 have frequently repeated the first experiment, but "*

nev'jr have succeeded nearly so well as at .first; a little hiss-
ing noise, attended with a small flame, only occurring now

F 2 and '

68 DESCRIPTION OF A IIIIEUMAMETER.

«nd then, occasioned in consequence of the bursting, I tma*
gine, of the glands of new flowers; which, from their not
being before developed, remained uninjured, during former
experiments.
The glands de- Qn examining the plants after the combustion, 1 ob«
these experi- served, that the glands wers completely destroyed; and thui
ments. I was led to suppose, that the resinous fluid which they con-

tained was burnt during the explosion; and not that hidro-
gen, or any inflammable vapour was exhaled. Since after-
trtd no smell experiments never sucreeded so well as the first; and
«Tcrper«:h'ed. ^^'3^^*-' ^^^^ smell of hidroj^en was never present, either
before or after the experiment, 1 tljiuk I am stretigthened
in my opinion. At the same time, however, I confess, that
I am not completely satisfied with my own observations,
and therefore wish that some one, who has convenience,
would not only repeat the experiments, but communicate
the result of them to the public, and thus either ascertain
the truth of what I have reported, or annul it altogether.

XI.

jOescr'ption and Use of a Uheumameter, to estimate and
compare the Velocity of the Current of Rivers ; bi/ Mr.
Regnier, Conservator of the central Musetiin of ArtiU
levy *.

©ifFcrcnt jj^ ROM Mariotte to the present day men of the first emi-

uieans em« i^ei^ce have employed different means to estimate the velo-
ployed to mea- «

sure the velo- city and force of rivers; and their methods, more or less
city of rivers, ii^genious, seem to leave nothinsj to be desired. 1 may incur
the imputation of temerity therefore in bringing forward
another, perhaps not equally good ; but as it is very sim-
ple, attended with little expense, and requires no calcula-
tion, it may suit a great many persons, who are desirous of
erecting mills or other works on rivers, with the velocity of
which they are unacquainted.
Bynamometer lyj^^ Gauthey, inspector general of bridaes and highways,
applied to this ' ' . =* r • «u i r

purpose, first employed my sprmg powderproof m the shape ot a

• Abridged from Sonn'mi's Biblioth. Physico-ccon. March, 1810, p. 193.

steelyard.

DESCRIPTION OF A RHEUMAMETER. gg

steelyard, to ascertain the farce of a stream on a given sur-
face. His process is analogous to that of the bent lever
balance, as described by Michelotti in his work on Experi-
mental Hydraulics; but his method is not so simple, nor
his apparatus so cheap and portable, as that of Mr. Gau-
thier.

I have observed however, that the hand which holds the Improvement
rod, to which the instrument is tixed, is liable unintention- J-JjJ,''' ^^'^^ ^^^
ally to give it an additional impulse. This incouvenit^nce
has led me to employ the steelyard in a difiereut manner,
which appears to me more convenient and more accurate,
and affords the double advantage of measuring in distinct
manners both the velocity of the current, and its absolute
force on a given surface, so that the two modes of exami-
nation mutually check each other.

The apparatus consists of a cork log, or float, 10 cent. Apparatus Ce
[4 inches^ square, in the shape of a cube, so ballasted as ^^"°^***
just to sink to the level of the surface. A small reel, turn-
ing very freely, on which is wound a silk cord of a given
length, to measure the distance the log should float. A
small dynamometer, resembling that I constructed to mea-
sure the strength of threads of silk, cotton, or flax. With
this apparatus, which may be carried in the pocket, the
action of a current may easily be ascertained.

To the upper part of the log is fastened a silk cord,
forming an acute angle, like the string of a kite; and to the
point of the angle is hooked a red string two yards long,
tied to a green string ten yards long, which is entirely
rolled up on the reel. The other end of the green string
is fastened to the reel, which the observer holds in his hand.
A cord of two colours is used, to distinguish the part in-
tended to measure the distance passed through from that
which should be in the water with the log.

I have preferred a silk to a hempen cord, not only be-
cause silk is stronger and mtore pliable, but because it does
not twist in the wat€r, and retard the progress of the log*
To satisfy myself of this, I have thrown into the water littl«
pellets of paper, which floated freely by the side of the log;
and the eye could perceive a sufficient uniformity in a dis-
tance of ten yards, the measure fixed on.

To

yO DESCRIPTION OF A RHEUMAMETER.

Method of ^q use it, a boat being anchored in the stream, the log

is to be thrown into the water, and suftered to float away,
till the whole of the green cord alone remains on the reel,
which is stopped at this point by a catch. One person then
looking at a seconds watch gives the signal, when the second
hand begins its revolution, and instantly the other, who
holds the reel, sets loose the catch ; the log floats on, and
the time it takes to riin out the ten yards of line shows the
velocity*.

To determine the absolute force of the current on the
cube, slip the loop at the end of the cord off the knob on
the reel, and hook it to the hole of the little dynamometer,
and the number of degrees shown by the index will express
the maximum of the action of the water on a surface of l6
square inches.

This action is not constantly the same, not only from the
effect of the waves, but from the natural current, which
appears not to be always regular^ In facf: we have observed,
in calm weather, without any apparent waves, that the
force of impulse varied from one insrant to another in the
proportion of 6 to 8, or even more.
Experiments But the velocity has a great action, as will appear from a
^* table of the experiments we ma«le at Paris between the

Pont des Arts and Pont-Royal, on the 20lh of July, I8O9.
The weather was calm, and the Seine a little below its mean
height, being at 1^^ met. [4 feet 11 in,] qn the graduated
scale of the Pont-Royal.

9n the Seine, ^irst situation, 10 yards from the side, opposite the wickets of

the Louvre.

J?xp,

1. Veloc.insec.|25 X

2 26^ f Force inhec^)5. :

3 26 J

2 tp 3 : in oz, avoird. 7 to 10^
g .,......,. 26 J

• The person who holds the reel in hh. right hand might dispense ■with
«n assistant, by holding in his left a stop watch, stopped at the end of the
revolution of the seconds hand. He would only have to set loose the
stop with the forefinger of the left hand, at the instant he disengaged th?
catch with the ri^^ht, and stop the watch again the moment the line wag
run off the reel. C*

S^C0^4

DESCRIPTION OF A RHEUMAMETER. ^J

Second siluatioiif in the middle of the stream.

1 HO

2 14 S .6tD9: 21to3lJ

^ 14 }

Third situation, \5 yards from the side^ opposite the street
des Saints- Peres.

1 28 ^

2 o8 > lto2: S^ to 7

3 26 J

Though these data are not very ample, it is obvious, GeneralcoTi«

1st, That the water at the sides of rivers has but little. elusions,
velocity : and

2dly, Xhat the velocity of the middle of the stream in-
creases in an extraordinary degree the impulsive force;
since the action produced on the log by a velocity of iO met.
[32f. 9 in.] in 14 seconds was from 21 ounces to 31|; while
by a velocity of 28 seconds it was only from 3j- oz. to 7«

On comparing afterward our experiments with those ofTheexperi-
Mariotte, made about \6GG in the same place, we found a o„e"inUie^*'''
great deal of similarity in the results." By means of little I7ih century,
balls of wax, ballasted so as to swim level with the surface,
he estimated the velocity of the Seine, at its mean height, to
be 150 feet in a minute, or 30 inches in a second. But
when we made our experiments the Seine was only 4^ feet
high, and at the timeof Mariotte*s it was 5 feet; a differ-
ence in height answering to the difference of velocity. And
hence we may infer, that a century and half has made no
change in the current of the river at this part.

The same experiments led us to compare the velocity of Velocity of the
the Danube with that of the Seine. In the Journal de Jt)anube.
Paris, of the 11th of July, 1809, is a note from Baron Pa-
kali, who says, that the velocity of the Danube, at its mean
height at Ebersdorf, is 4| feet in a second ; so that we may
consider it twice as rapid as the Seine at Paris.

Erplanatim of the Plate,
PI. II, fig. 3. a, a cube of cork, 4 inches square, bound Explanatlontf
round with pjickthread to strenglhen it. ^^« P'*^««

7i

tCIEMTlFlC NEW*.

b, a plate of lead, fastened to the bottom, to ballast the
cube, so as to float level with the surface.

c c, knots from which proceeds a silk cord, forming an
acute angle at the point d.

e, hook in the loop of the red cord about two yarrfs long,
tied to a green cord of ten yards, rolled up on the reel f, to
measure the velocity.

g, a flat piece of hard wood forming a base to the reel, in
the centre of which is a small rod of polished steel, on
which, as an axis, the reel turns freely.

A, tail of the catch, on which the thumb rests, to let the
reel move at the signal given.

Fig. 4. i, a small dynarpometer, with an index, to mark on
the arch the maximum of the impulse of the current.

Fig. 6. A, the log, floating in the stream.

/, the observer in a boat, holding in his hand thedynamor
meter, to estimate the force of thp current, after having
measured the velocity.

French Insti-

SCIENTIFIC NEWS.

French Institute,

A.N analysis of the proceedings of the raathematical an4

tuie. physical class, during the year 1309, by Mr. Delambre,

perp. sec, has just reached us.

„ , , „ Ihe question of the stability of the planetary system has

Stability of the ^ , , . 4/r i i i

planetary sys- been still farther pursued by Mr. Lagrange, who has exa-

'*™' mined it in a more general point of view, extending it to a

gystem of bodies acting on each other in any manner what-
ever. He also purposes to investigate the relation of the
planets round their centre of gravity, considering the devia-
tion of their figure from a sphere, and the attraction the
other p'aiiets exert on each of their particles.
_ . Mr. Poisfton, as a continuation of his inquiry on the ya-

•hp Earth, nations of the elements of the planets, has composed a pa-
per on the rotation of the Earth. As Mr. Lagrange has
noticed the extreme difficulty of this problem, we cannot

be

SCIISNTIFIC KEW8. V^»

be »ttrpnie(ito find, ^hat foroiulft have occurred to Mr*
Poisson, the absolute summing up of which appeared to
him impracticable. His object was to examine the influence
of the term of the stcond oider in the expression of tlie
velocity of the Earth's rotation. These terms arise from
.expanding? into a series the function expressing the sum of
the products of the pjass of each body attracting by thats^
of the body attracted, divided by the mutual distance of
these bodies. As it is impoi^^ible to calculate all these
jterqis, the object is to bring forward only those that merit
attention. Mr. P. accordingly examines in the first place*
whether even those that depend en the Sup might not be
neglected; and he finds, that they are always in fact v«ry
small.

As to i]ye figure of the Earth, Mr. P. supposes, tbat»^
without the action of the Sun and Moon, the Earth would
turn precisely round one of its principal axes. This i»
justified by the physical state of things, since we do Dot-
perceive in the altitudes of the pole, observed at different
places, any of the oscillations, that would result from a dif-
ferent hypothesis, and the duration of which would be
about one year. By similar considerations he expunges
the terms relative to the otlier two principal axes, which
can never become sensible but on hypotheses of little pro-
bability, which would give to the rotary motion of the Earth
periods of less than two y<^ars, which have never been oh*"
served. He afterwards shows, that the equations to be
summed up in the successive approximations preserve the
same form ; whence be concludes, that the axis of rotation
will always coincide nearly with the shortest of the Earth's
principal axes, and that the poles will always answer to the
same points on the surface.

But, though the latitudes may not vary so as to deserye Mar th«re
any attention, or to be perceptible to astronomers, is the J^^J^jg^^*^^,^'
rotary motion so uniform, fi$ has been supposed ? If its ine-
qualities be of a very short period, and not very perceptible,
they may escape our notice, and yet in a certain degree
affect all our observations, and the consequences deduced
ft-om them. Suppose, for example, that the pole, instead of
the 3^^' of its circle, passes only through 350* ^ and that the

latitudes

^4 SCIENTIFIC ME-Vrs.

latitude of Paris observecl at a ejiven period should appear,
in consequence ot an 0!*cilla ion then at iu maxim um, to(v
great by \'\ tlie errour btiii^ proportiouji to the cosine of 0;
the year following at the same time it would be proportional
only tothecosineof 350*, and soon, till at the end of 9 years it
would he nothinj?. At the end of 18 years h«iwever it v on Id be
1" in the or'posite direction, whence a diiference of 2" miijht
appear in the altitude ot ihe pole; but so small an inequa-
Arfonentt for }\ty in so long a period would not b^- noticed. To show the
***^ probability of this we mi«ht say. that Bradiev, from a num-

ber of observations of the polestar in 1753, found the lati*
tude of Greenwich 51* 2B' 41*5", though !romastill greater
number he had before found it only 51* 28' 38". We may
suppose therefore an osciliatioi of 2" with a short period;
or a greater oscillation, of which only a part h^s been ob-
served. The latitude of the observatory at Paris too was found
to be 48* 50' 10' at one time, and 48* 50' 14" at other
times, by Lacaille, Cagnoli^ Mechain, and myself. These
differences might be ascribed to oscillations of at least '4 '»
and a period of about 15 years, so that there would have
been 2^^ periods between Lacaille and Cagnoli, and one
But probably only between Cagnoli and us. But 1 must add, that,
there are none, jj^y-jjg examined at large the observations of Bradley for
five successive years, I have perceived no trace of these
oscillations ; that if there were one of 2 ", it might fre-
quently be confounded with the errours of observation;
and that the dirlereuce of 3*5 " between the two results of
Bradley might arise from his having changed his quadrant
in the interval, and particularly from the errour of colU-
naation, which for his old quadrant was 1'74'> and for the
other 8', not being known with suffjcieut precision, of
which there are many instances. Thus we may take it for
granted for the present with Mr. P. and astronomers in
general, that there is no oscillation, or a very minute one;
tboogh thi» but of this we have no deiiiODstialion, and it is a point of
remains to be fti:^fficieut importance, to be worth ascertaining with an in-
• * slrumeut, in which no errour in the collitnation is to be

apprehended. For this itjw'ould be sufficient to. observe
for some years with Borda's circle the meridian alti-
tudes of the polestar above and bel^w the pole during

the

SCIENTIFIC NEWS. ^

the months of December and January: an oscillation, were
it but of 2", 9DuId then scarcely escape observation; as w«
are indebted to Mr. P.'s analytical investigation for th«
knowledge, that its period rannot be a complete year, so
that the latitude must undergo a gradual variation, if ob-
served rci^ularly at thesame period,

Mr. Poisson has also investigated some other formulae,
with a view to simplify them, and render them of more
easy application. The firstobject, to which he has applied
them, is the motion of a point attracted toward a fixed cen-
tre, according to any given function of the distance: and
the second is the rotary motion of a body subjected to no
accelerating force. His paper teriniuates with the follow-
ing remarkable conclusion, ** 'lih perturbations of the Perturbations
rotary motion of solid bodies of whatever figure, to what- goUds^*'^*'*^
ever attractive forces they are owing, depend on the same
equations as the perturbations of the motion of a point at-
tracted toward a tixed centre. Thus the precession of the
equinoxes, and the nutation of the Earth's axis, will be
expressed by the same formulae, as give the variations of »

the elliptical elements of the planets.

Mr. Legendre has given us some new theories in fluxions, Theore»sia
and approximations of easy application. fluxions.

Messrs. Laplace and Bouvard have each investigated the Motion of the
problem of the motion of the Moon being such as always to "^*^'^*
present nearly the same face to the Efirth. Mr. Bouvard
shows, that there is no need of recurring to approximations.
His method, though different from mine [Delambre's], is
equally precise and direct ; and his results agree perfectly
with those of Mayer, thus atfording an additional proof of
the ability of that great astronomer.

Mr. Burckhardt has revised and enlarged a paper on the PertmbatioTK
perturbations of the planets, which he composed in 1803, ^'^^^^ pkocis.
but had mislaid.

To this is added another paper, which will conclude the Ltinar tabl«$.
volume for 1808, now about to be published. Theory has
not yet been able, or has not ventured, to undertake the
calculations necessary for determining the coefficients of
the different^ inequalities of the moon, and they have been
taken from observation. The raethgd fpllowe<| io these re- ;
, . search e|i

J^ SCIENTIFIC NFWS.

Lunar tablas. iearcheft U to leave in uu indeterminate form, in the for-
mula of the longitude or latitude of the Moon, all the un-
known coefficients, multiplying them by the fraction which
€xpr€sises the aioe or cobine of the argument, on which the
inequality depends. All the equations in which the
same coefficient has the highest pobitive multipliers are
brought together; another 8um is made of those in which
this coefficient has the highest negative cofactors ; and from
their comparison resulis the Uiost probable value of the
unknown coefficient, that which agrees the best with the
observations. This method, which must have been followed
by Mayer, has since by JVIasson and Buerg, and all who
have calculated tables withn these twenty years. This
method i« easy, and has no inconvenience but the length of
the calculations when observations are taken by thousands;
as must be done if we would determine the coefficients of
those inequalities, which from their smallner-s have been ne-
l^lected in the theory of the Moon : and Mr. B. now offers
Wft a very simple method of abridging these calculations,
since it dispenses with the calculating and summing up of
all the sines of the argument.

Conceive a series of sines of arcs, forming a decreasing
arithmetical progression from 90° to 90° minus a given
limit y : Mr. B. has found, that we shall obtain with suf-
ficient precision the value of the coefficient sought, by em-
ploying, instead of the mean arithmetical sine, the sine ofy
divided by the arc i/. According to this idea he gives the
fules to be followed in these researches, where we are liable
to the vexation of finding after long calculations, that the
inequality sought is null, or altogether imperceptible. As
a trial of his method, Mr, B. has made a selection out of
1300 observations by Dr. Maskelyne, and proposed to de-
termine an inequality, which should have for its argument
the mean anomaly of the Moon, increased by the argument
that regulates the inequality, the period of which is 180
years. Nine hundred observations gave him 4*7 " for the
coefficient. He is desirous, that farther examination should
be made of the goodness of an equation, which so well de-
serves to enter into the tables.

Mr, Burckhardt proposes some other calculations for the
iJi^-'? i improveraept

SCIENTIFIC NEWS. yy

improvement of the lunar tables, which require only some

one of sufficient coura^ to dndertake the task.

In another paper the same astronomer has calculated the Galley's
/. ri 11 « L 1 1 • comet,

perturbations of Halley s comet, which reap; earen in 1759,

and is expected about 1835. He has found, that the at-
traction of the Earth will have altered the period of its re-
volution sixteen days.

Having formed the plan of a grand geodetic operation Methods of
for joining observatories differing greatly in longitude, he a^injuihs,"^
was aware of the importance of an accurate determination of
the azimuths to the success of his scheme, and in conse-
tjuence examined the advantages and disadvantages at*
tached to the different methods known.

He has also determined the dip with two different needles. Dip of the
one of which gave 68° 47*1', the other 68" 47*4', on the 10th needle.
and 20th of August, I8O9. Mr. Gay-Lusi«ac had made
similar observations with another compass about the same
time; and as his dip differed sonfie minutes from that of
Mr. Burckhardt, thCsSe two gentlemen have agreed to repeat
their trials, in order to ascertain, if possible, the cause of
the diffi-rence.

Mr. Biot has read a note on the observations of the pen- Figure of the
dulum made at the two extremities of the meridian, namely Eartii.
at Formentera ard Dunkirk, in company Avith Messrs.
Arago and Mathieu, and on the oblateness of the Earth
thence resulting. All these observations exhibit a surpris-
ing agreement with those made at Bourdeaux, Figeac, and
Paris, by the same gentlemen and Borda ; and give an ob^
lateness differing very little from ^^-g-, which I have deduced
from a comparison of my arc with that of Peru.

Mr. de Prony having been of opinion, that Mr. Ramond's Baroipetrvaifi

cofeflficiet^T foi* barometrical measurements was too ureat '"^^^"f«*

^ ments,

for incouf^iderable heights, and the original coefficient of
Laplace better suited to them, Mr. Ramond has, several
titties taken the height of various places near Clefrnond-
Ferrand, by the barometer; and Mr. de Courbon mea-
sured the same heights trigonoinetrically. The heights
were from 300 to 6C0 yards. The differences were from 1
yard to 0*05. Stilt the differences betweenthf* heights as-
signed to Mount Cenis by Mr. Raraond and Mj*. de Prony

remain

yg SCIENTIFIC NEWS.

remain to be accounted for; since Mr. de Prenyls baro-
metrical measurement of that height is confirmed by the
measurements of Mr. Daune, who had to take the luvels
during the construction of the road over it.

In order to introduce the use of the barometer in geode-
tical measurements, undertakea as preliminary operations
in planning roads, and particularly for canals that have to
traverse heights, wl)ich would be a considerable saving of
time and expense, Mr, de Prony has undertaken a series
of experiments at Paris and in its vicinity, to ascertain the
coefficient best adapted to small heij^hts. lie verifies the
barometrical heights by trigonometrical measurements with
tke repeating circle. Mr. Mathieu observes at the imperial
observatory, and Mr. de Prony at the little observatory
constructed for him over the pediment of the House of the
Micrometers Legislature. Mr. de Prony employs two micrometers, dia-
applicd to the metrically opposite, for adjusting ihe coincidence of the
aroeieter. jndex with the tangent to the summit of the mercury, by
means of which he makes this adjustment superior in accu-
racy to the measuring by the vernier.

Scarcely a private meeting passes without the class bear-
ing some report on new machines or inventions, and on
papers subnntted to its examination by persons not yet
members. As it is impossible to review all these, I shall
only mention :
propagation of 1- Researches on the velocity of light, by Mr. Arago,
ligli** now member of the class, who has proved, that this velo-

city is the same„ whether it come directly from the Sun or
stars, or from a fire kindled on the Earth, or by reflection
from the Earth, a planet, or any terrestrial body,
rire-enfiae- ^^* ^^ fire-engine by Mr. Cagniard-Latour, who has mnde

in it a very happy and inverse application of the screw of
Archimedes.
Electrochemi- ^" ^^'^ physical d<'partment of the class the most proroi-
qtX Inquirir:, nent are the researches of Messrs. Gay-Lussac and Theuard
in the brilliant career first opened by Mr« Davy; and
though these gentlemen do not appear lo contemplate every
fact with the same eyes, the progress of science cannot fail
to be promoted by the discassions that arise between
thvm.

We

SCIENTIFIC NEWSif), in j 79

We are likewise indebted to Mr. Gay-Lussac for oh- Comblnatioas
servations on the combinations of gaseous substances with
eucb other, intended to show, that they always unite in
simple ratios.

These Observations are followed by a separate paper on Compound* <if
nitrous vapour, and on nitrous gas as an agent in eudiome- '^*^^^^*
try. In this we see clearly the influence of quantities on
the result of combinations. If two parts of nitrous gas
and two of oxii^en be mixed, nitric acid is produced, and
one part of oxigen remains free. If on the contrary four
parts of nitrous gas and ene of oxigen be mixed, nitrous
acid is produced, and one part of nitrous gas is left free.
Ana, as nitrous gas is composed of equal parts of oxigen . .

and nitrogen, we know theconstitutions of the two acids
with precision.

Mr. Guyton de Moiveau, in a series of experiments on Water decom*
the diamond, and substances that contain carbon, found dia'mooX,
that water was deccniposed by the diamond at a very high ^ j 0
temperature, and carbonic {i*,id produced. ■ t

Mr. Sage has imparted his researches on the revivification Mr. Sage,
of silver by mercury in the nit'ate of silver; on an acetate
of ammonia obtained from wood by distiiiation ; on the
analysis of the- calcareous stone named typogiajjhioai : on
the magnesia contained in shells, madrepores, lirapstoie, - ^

and arragonite; on an arenaceous iron ore; on an unknown -^^

petrifaction; and on a cupreous and ferruginous, petri lied
wood.

^To be continued. J

dt

To Correspondents,

A Constant Reader may find many of the articles he
mentions in vols. XVIII, XlX, XX, XXli, and XXIII;
others will be inserted as o importunities oCcur. His con-
cluding suggestion will be considered.

METEOROLOGICAL

: METEOROLOGICAL JOURNAL^

For APRIL, 1811,.

Kept by ROBERT BANCKS, Mathematical Instrument Maker,
in the Strand* London,

THERMOMETER.

<

o «

BAROME-' ^,^/

TER, RAIN,

[noted at

9 A.M. ,9^-^-

WEATHER.

Day.

Night.

Fail-

Fair

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Snow

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Ditto

Ditto

Fair

Ditto

Ditto

Rain

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Ditto

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Rain

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Rain

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Cloudy

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Fair

Showery

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Ditro§

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46**

40

47

46
45
50

52
44

39
40
36
37
33
41
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50
55
55
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49
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59

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47
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55
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42
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39
41

43

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58

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56

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62

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56

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56

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54

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41

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60-5

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32
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•015

•890 Inch, since last Jounk

• Intertening Fogs. f ^a'" '" the NJ^hf.. % Boi»terous at 12 with rain.
§ Lightnfng, about 9 P. M.

JOURNAL

of

NATURAL PHILOSOPHY, CHEMISTRY,

THE ARTS-

jUNjSy isn*

ARTICLE I.

iy^scrtpiion of a Method of Roofing Buildings securely with
Flagstones, By Righard Lovell Edgeworth, Es<l»
F. B. 6. M. R. L A.

To Mr. NICHOLSON. '

SIR,

Jj^ Had occasion some time ago to roof a large building in
an uncommon manner. I send you an account of it; as it
has succeeded; and, as I believe, it may be useful in many
places where slates and tiles are not to be had.

The gaol of Longford, in Ireland, which was built about Gaol of Lorty*
twenty years ago, was covered with a circular arch of bricks; ^o^d roof«<i
upon wliich broad flat stones, commonly called flags in this
country, were laid with the best mortar that could be pro-
cured ; these thin stones or flags were placed side by side ;
the lateral joints were filled up with mortar; and ajl the /

courses, as they descended, lapped over each other about
two inches. After a short time the sun and frost cracked P«nct/*te4bj
the mortar between the joints, and the rain found a way ^*
into every part of the building.

Vol. XXiX.No.l32.— Jvj(E,1811. Q Op«

85; FLAASTONB ROOF.

Attempt to One o£ those men of practice, as they are called, front

a cement ^ having been employed practically in building, undertook

for forty or fifty pounds to remedy the evil, and by sicurious

cement to render the roof impervious to water. He laid on

his hot cement of resin, and wax, and brick-duat, &c. The

first summer shower passed off without penetrating through

the joints, and the undertaker received his money ; but in a

did not sue- short time things were as bad. as ever, and the miferable

^^ ' creatures under confinement were drenched with rain and

snow in every part of the prison.

Expense of a In the year 1809 the Grand Jury of the county of Long-

coTering ^^^^^ desired, that I would endeavour to staunch this roof at

any expense, that might be required, I received proposals

for^ covering it with lead, and with copper: this could not

be done for less than seven hundred pounds.

»nd of slatinf . I then proposed to belt down rafters upon the brick

arch, so as to form a polygonous roof, upon which slates

might be laid in the usual manner; but this I found would

cost above four hundred pounds. It then occurred to me,

that the flags on the roof might be so ordered, as to effec^

the intended purpose.

Managem«nt I took off a portion of the flaers in fine weather, and with-

of the flaes .

themselves to ®"* removing them from the top of the building I had them

keepoutihc cutinthe following manner ; the flags (a a, PI. Ill, fig. 3) were
about three feet long, two feet or two feet six inches broad,
and two inches and a half thick. The upper course was of
fine even flags four feet broad, and each of considerable
length, and under this course the roof was secure every
\fhere, except between the lateral joints. To prevent the
rain or snow from penetrating between the upper and under
courses or horizontal joints of the flags was the first object.
For this purpose a groove was cut an inch deep in theaJir-
face of the upper part or top of those flags that were next
the eaves; this groove was cut within one inch of the top
of the flag. A similar groove was cut in the under side of
tlie next course that lapped upon the lower course, and so
..•nfrom the eave to the ridge; so that the upper flag or
» "Stone could hook upon the. under one, as may be seen in the
section, fig. l.PU III.

Jfie lateral r^^ ngjj^ object was to secure the lateral joints. T^

•*^ effect

1

FLAttSTONE ROOF. g5

effect this purpose, grooves were cut into the upper surface joints covered

alon^ each side of every flag three quarters of an inch deep

at one inch from the edge, see tig. 2 and 3, where a section or

profileis given. To cover these lateral joints caps of lead were

laid from the ridge to the eaves, a cap for each flag, or

rather for every pair of flags. These caps, which had the

appearance of a bead, were fastened over the rabbets or

grooves of the flags by copper nails, c, driven through the

caps into the juncture between the flags. These nails were

made fast by slips of sheetlead d d iig. 3, put between the

stones. A representation of the full size of the grooves in

the stones of the lead cap and mushroom nailsis given, fig. 3.

Where holes were made through the lead caps, the water
might find a passage; but this was prevented by preparing
the holes in the lead in such a manner, as to stop the water
above the hole, and to turn it aside from the direction which
might be hurtful. The caps before they were laid in their
proper places were turned upside down, and where nails
were to pass, a burr or button, b, 6, was punched in the
lead half an inch deep, and by a proper tool passing through '

the punch, a hole was made in the centre of the button.
The cap, when put into its place, covered the ridges of the
flags between the grooves, so that no water could find an
entrance between the joints of the flags ; nor could any
water rise above the tops of these buttons, because the Th;$ effectual,
descent of the roof would carry it off". Besides, the button
or burr was covered by a mushroom-headed nail , the rim of
which entered a little into the lead round the burr and pre-
vented small particles of snow from gaining admittance.

The holes in these caps might have been closed by solder;
but whenever any work that is of difficult access is to SimpHcitv ad-
be performed, it is always advantageous to have it executed ^^"^^K^°"=*'
by some one workman, in a manner that requires no diffi-
cult art or complicated apparatus. And I find that not one
drop of water has penetrated through these joints during
the two winters that have passed since they were covered
according to this plan.

At the commencement of the business many difficulties Difficulttea
with respect to the scaffolding were started. Very long thI^s<SoldiM
ladders were requisite. Cripples hung on iroji stauncheons
G2 in

94 FLAGSTONE ROOF.

in the wall were deeraed insecure; and the country work*
men trembled at the idea of being perched so high from

■uiniounted. the ground without any apparent protection, I constructed
eight light ladders, each six feet long; these were wider at
one end than at the other, so as to permit them to be
joined together by small bolts passing through the ends of
both ladders. The ladders, thugjoined, applied themselves
commodiously to the circular roof, they were hung across
the top and fastened by ropes, passing over the ridge ofthe
rooftotheironbarsofthe windows of the upper cells on the op-
positeside ofthe gaol,which happened tobeempty. On these
ladders movable cripples were placed wherever a scaffold was
wanting : on these cripples, which extended six feet from the
roof, strong planks were laid, with ledges to prevent their
slipping sideways; round this Ecaffold a coarse substantial
handrail was tied. The passage to this scaffold was through
a large opening in the top ofthe roof whence the workmen
descended down the ladders to the lower platform, and
thence to any part of the roof.

Expense. The scaffolding of this work cost but fifteen pounds, and

the repair of the roof, exclusive of some other work that was
carried on at the same time, came within one hundred and
forty pounds.

As I may not have an opportunity of mentioning it in
another place, I hope that you will excuse me for inserting
a circumstance relative to this gaol, which is certainly not
connected with the immediate subject of this letter ; but as

*The moment the scaffold was finished, I went upon it myself, and
from that time no objections were made. Notwithstanding all the pre*
cautions that had been taken, a fatal accident threatened the lives of the
workmen. It has been said already, that the repes which held the lad-
ders were tied to the bars ofthe upper cells of the gaol. One morning,
towards the close of the business, the principal workman found the lad-
ders, and the scaffold that was attached to them, giving way. He had
sufficient presence of mind to throw himself off the scaffold on the roof;
as he was near the top, the slope of the roof was not sudden. He could
therefore stick there till his companions relieved hiro.

The cause of this sudden failure it was impossible to foresee. A mad
woman had been accidentally put for a single night into one of the upper
cells; there by moonlight, with that mischievous alacrity whick is ofteri
r> the accompaniment of insanity, she untied the cords, »nd left the scaf-

fold without support.

it

FLAGSTONE ROOP. 85

it relates to public buildlngi of all sorts, it cannot be with-
out some general interest.

In laying the first stone of the gaol of Longford twenty Documents
years ago, I placed in a cavity sunk in a large stone, under the foundation
the S. W. corner of the building, several tiles, upon *^®'" P®*^®"^y»
which, before they were baked, there were inscribed various
memorandums for pofterity, the Greek and Roman alpha-
bets, the latitudes and longitudes of Paris and London, the va-
riations of the needle, the nature and dates of various inven-
tions, of gunpowder, of printing, of the steam-engine, of iron
bridges, of the balloon ; some of the discoveries of chemistry,
and several remarkable events, with the names of celebrated
books, and of their authors.

If this were done in various places in Europe, it might This recoio-
hereafter be not only gratifying to future curiosity ; but ^ther •!:».
might be useful to mankind. We have reason to believe, sions.
that fictile compositions are among the most durable sub-
stances that exist, and as we may, with the greatest ease, in-
scribe what we please on them before they are baked ; it is
but a small sacrifice to posterity, to give up an hour or two
of leizure, from a hope, however feeble it may be, of pre-
serving some of the discoveries, which have hitherto been
made in art or science. Swift tells us, that a shrewd fellow Ppsteritj.
inquired, why we did so much for posterity, when pos-
terity has never done any thing for us. It is true, that
posterity has never done any thing for us; but the idea
of a posterity, that can bestow posthumous fame, has ever
been and ever will be an excitement to present exertion.
Our own immediate descendants reap the harvest which we
sow, and nothing is more natural or more laudable than ^
wish t« preserve our names apaong those who have been b«?»
nefactors of society,

JEdgeworthtown, Ireland,
the 17th of April, I8\l,

IL

8^ Sfiip's LIFEBOAT*

II.

Method qfmakhg any Ship's Boat a Life boat , to preserve the
Lives of the Crew in imminent danger ; by the Rev. Jame«
Bremner, Minister of Walls and Flota, Orkney Islands*,

Case of Ship- J7XAVING a great many years ago witnessed a melancholy
^"^^ scene of shipwreck, and seen men perishing at little more

than the distance of one hundred yards from the shore, it
forcibly struck tne, that thout^h there was no possibility of
getting from the shore to them, yet there was a great proba-
bility that means might be found, by which those in such
situations might with safety be enabled to effect their escape
to the shore; and farther considering, that the very preca-
rious aid of some accidental piece of wreck (under every
disadvantage and in a tempestuous sea) sometimes serves to
save life, I was confirmed in the opinion, that some method
might be devised, which, upon good grounds, would hold
, forth the promlhing prpspect of safety in all the common
and general cases of shipwreck. Hence it was, that to
devise such a scheme became the object of my research ever
after.
Plans for say- The following plans (especially the first) are so simple, and

jng Persons ^|^^ ^^^^^ ^^ obvious, that I cannot allow mvself to think
J^uipwreckea.

that any seaman can entertain the smallest doubt, but that

a boat so prepared would live in any sea whatever, could nei-
ther sink nor overset, and could carry in safety a number of
people, in proportion to her size, over a bar, or from the
wreck to the shore through any surf.
Buoyancy That empty casks must float, almost wholly above the sur-

of empty Yace of the water, is so clear, that no person can be so ab-
surd as to question it; and it is equally certain, that every
cask will support weight of any kind in proportion to its
size. In order then to accomplish theend proposed, there is
only one thing more wanted, and that is, by means of su65-
cient seizings or holdings, to secure the casks in their
places. Were you to tell a seaman, that be is not master of

* Trans, of the Soc. of Arts, vol. XXVIII, p. 135. The silver medal
#f the Soci«ty and twenty guineas were Toted to the author.

^^9.

ship's lifeboat. 37

this mighty operation, it is easier to conceive than to express^
the contempt he would feel, and the energetic reply he
would probably make to such a supposition. If then these
are undeniable points, it must follow, that wherever the boat
can be had recourse to, all that is contended for in the plan
must be granted.

It no doubt has been upon these simple and obvious prin-
ciples, that those corporate and public bodies, and hundreds
of seamen to whom the plan has been communicated, have
so readily and entirely approved of it. But however re-
spectable and authentic these testimonies (afterward to be
mentioned) may be, I lay no stress upon that point, neither
do I ask any credit for it, but freely submit my statements
to the great body of seamen in general, leaving them to be
judged of, not with liberality only, but with severity, con- ,
sidering that it would be a crime of the first magnitude, to
advance a single argument or suggestion, that could have
the smallest tendency to mislead, in a matter so solemn and
important as where life and death are concerned.

Were I to go back to cases that are well known to have
happened, I could easily point ©ut many, wherein had this
plan been thought of, there can be no doubt but it would
have been attended with the happiest consequences; and
probably the recollection of many seamen may furnish cases
of the same kind, which have happened within their owq
knowledge.

I shall only add, that I expect no benefit or advantage
whatever to myself from my perseverance and labours on
this subject, nor reimbursement for an expense of some
hundred pounds which it has cost me in repeated journies to
Edinburgh and London, as well as in experiments, which a
living of less than seventy pounds a-year could very ill af*-
ford ; but I shall nevertheless reckon myself amply rewarded,
if what 1 have to propose shall at any time, or in any case,
prove the means of relieving from the deepest distress, and
of rescuing from otherwise inevitable death, even a few of
those who have had the misfortune to be involved in all the
horrours of shipwreck.

Mariners are unavoidably exposed to incomparably greater Hardship! anrf

hardships

SS «RIP*S LIFEBOAT.

hardshipi tnd sufTftrings, than are to be met with in anj
other lin« in human life.

While the labours of all others are moderate, and find
relief at stated intervals by day, and repose by night, the
teaman must contend with the storm so long as it lasts, and
encounter danger at a moment's warning, whether at mid-
day or midnight. Whilst the tempest rages, no respite can
be allowed hiq;^; he must keep hjs station without intermis-
sion, and after toiling above strength and above measure, it
is often his hard fate to be shipwrecked at last.

The complicated distress attending th'^s freq^uent and
fatal disaster it would be in vain to attempt to describe in
any words; nor is \t possible to conjecture nearly the num-
ber, which is added annually to the innumerable multitude
of dead which the ocean contains.

Scwnetimes several hundreds in pne ship are involved in
this direful calamity, where the misery of eagh sufferer is in-
creased, in proportion to the accumulated wo that surrounds
him; the cry of despair is heard on every side, and in dis-*
traction each exclaims. What shall we do ?

Amidst overwhelming waves and vyreck, the mariner suf-
fers in his person all th^t a living man can undergo, and in
his mind all the anguish that despondence can create,
heightened by the agonizing thought, that he is never more
to behold wife, child, family, or friend; still however amidst
all his sqfierings an ardent loveof life preyails, and the hap-
less mariner, struggling hard to preserve it, clings to vfh&U
ever seems to promise a momentary reprieve.

In the mean time the wreck is rapidly giving way, some
are washed away in one place, and others iq another ; those
trho remain redouble their efforts for life; but alas! they
strive in va'm; one decisive blow ha? dashed their last and
only support to pieces, and all are going down together— »
a general shriek is heard— to be heard no more! the me-
lancholy scene has closed, ap^ neither survivor i^or wreck is
left behind.

Any plan then that has for its object to afford relief in
situations of such extreme distress, and which seeks to ex-
pend the same benefit to thousands of perishing men in

futyr^

ship's lifeboat. 89

future ages, will no doubt meet with a favourable reception
from every humane and benevolent mind.

But humanity and true benevolence are not merely spe- Truehuira-
culative, but active principles; and wherever they I'^^^ly princhUe/*'*
exist, the helping hand is instantly stretched forth, to exe-
cute the dictates of the feeling heart.

As no subject can be more interesting to individuals than
the present, or more important to society, may it not then
be expected, that every friend to humanity and to his coun-
try will not only heartily wish success to the present plan,
but also lend his best assistance to have it brought into all
the practical etlect, of which it may be found susceptible ?

It is to be understood, that the plan is intended to apply
to cases of shipwreck in general, and that it may very often
succeed even in cases of extraordinary difficulty and peril.

This will comprehend the far greater number of all ship-
yrrecks that happen, and the authqr thinks himself war-
ranted to say, that no solid objection can be offered to the
effectual operation!^ of his plan to this extent, and that it
will be found fitted to answer all the purposes of a life boat,
by saving lives, where other^Yi§emen ipust inevitably have
perished. '

At the same time he begs it may be understood, that heTliepkn ap«.
does not speak with this confidence from his own opinion conlpetent
only, however well-founded in principle and experiment it judges,
may be, but because the plan itself, after repeated investi-
gation, has received the unanimous testimony and approba-
tion of professional men, and of men too who must be al-
lowed to be the most competent as well as the most re-
spectable judges in the kingdom, namely, theTrinlty House
ofLeith, in whose records a copy of it will be found.

The Report of the Highland Society of Scotland confirms,
that in their Committee appointed to witness the experimentat
Leilh there were naval men of that number who were com-
petent judges, and in whose skill they could confide, and
for this reference is made to the Appendix of their second
volume.

It has been repeatedly submitted to the Trinity House of
London, It was first submitted to them by Lord Melville,
the treasurer of the navy, and their answer under the hand of

90

The plan zp-
proved br
competent

SHIP ii LIFEBOAT.

their secretary is inserted in the forementioned Appendix,
signed James Court.

In the next place, the plan has been laid before the
Royal Humane Society, and they, not being naval men, do
submit every essay of that nature to the Elder Brethren of
the Trinity; and in consequence of their approbation a pre-
mium of five guineas was given by the R. H. S., as appears
from their printed Reports 1800 and 1801.

And to these attestations might be added the subscribed
approbation of more than one hundred ship masters, whonj
the author had occasion to see only accidentally, and whose
subscribed names are now in his possession.

It is under the sanction of such authorities and documents,
that it is now offered to the public, and they are such as
must be satisfactory to every impartial and candid mind.

They have been obtained without interest, favour, or
friend, and small premiums have been given without the
author's knowledge, till informed by letter that his plan had
received this mark of approbation.

It is impossible therefore to ascribe so honourable testimo-
nies and gratuitous bounties to any other motive than to the
conviction of the utility and efficacy of the plan, and an ar-
dent desire to promote an object so devoutly to be wished, as
the preservation of lives in cases of shipwreck.

The inventor trusts his statements will show, that he is
jiol unacquainted with his subject : and he shall only add, that
he has had more than forty years experience in the use of boats,
among dangerous tideways and rapid currents, such as the
Pentland Frith, and all the other channels among the Ork-
ney Islands ; and that he has been several times at sea on
shipboard, in storms that were attended with shipwrecks;
and that from such experience he is perfectly convinced,
that his plan is sound and unexceptionable, and is confident
that the period is not very distant, when it will come into as
great repute and sjeneral use as lifeboats, properly so called,
are now known to be.

The plan may be executed upon boats of all dimensions,
^nd the largest, provided they could be got out, would be
found the most advantageous: but, all circumstances con-
sidered, the size deemed in general best adapted for the

P^rpo8«

1HIP*S LIFEBOAT. 91

purpose would be any boat from sixteen to twenty feet m
length, which is to be prepared as follows.

Reference to the Plan of the Rev, Mr. Bremmer's Prepara*
ration of Ship Boats as Lifeboats , P/. 1 i I , Jig. 4 and 5.

Two additional ring-bolts are to be fixed in the keel with- Preparation of

inside of the boat. One to be placed one third of the boat's f ship's boatt.

06 used as %
length from the stem. The other one third from the stern, nfeboat.

Two auger bores are to be put through the keel withoutside,

and close to the garboard stroke. One of these bores to be

put about half way betwixt the ring in the stem, and that

next to it in the keel. The other about half way betwixt the

ring in the stern, and that next to it in the keel.

Plugs may in ordinary be put into these bores, to be
struck out, when occasion requires.

Those ring-bolts which are in ordinary in every ship's-
boat, the two additional ring-bolts in the keel, and the two
augur bores, are all intended as secure points of fixture, to
which seizing ropes are afterwards to be attached.

In the next place, two tight empty casks, (see fig. 4.) are Casks.
to be provided, of such dimensions that their length may fit
to the \vidth of the boat, when laid athwart ship, and their
diameters to be about three feet, and if larger so much the
better.

Each cask must be furnished with a sling on each end,
and each sling to have two eyes on it, about six inches asun-
der, and the slings so put on the cask as that the eyes may
be on the upper side when laid into the boat, that the seiz-
ing rope may pass through those eyes, in their way from ring-
bolt to ring-bolt.

One of these casks, so prepared, is to be laid in forward,
and the other aft; and each cask so near its respective ring
in the keel, as only to leave sufficient room for passing the
seizing rope through the ring in the keel.

By this means the vacant space, to be then filled up with
cork, will be left betwixt the cask and the bow forward, and
betwixt the other cask and the stern aft.

The requisite quantity of cork, according to the dimen- Cork,
sions of the boat, and the quality pf the cork, may be about

a hundred

SB SHIP*S LIFEBOAT.

a hundred and a half, or two hundred weight, for each end
of the boat, and that for each end ought to be made up into
two separate bundles, each bundle beinj? fitted to the width
of the boat, and the uppermost one forming an arch from
' gunwale to gunwale.

The cork is to be made up in canvas, done orer with soft
pitch for preservation, and each bundle marked and num-
bered according to its place.

. The casks and cork being laid into the boat, seizing ropeg
are then to be applied for securing them in their places.
Method of se- Here it is to be observed, that the single turn of rope
«»Jt^dcork. ^^^^^ ^s to go through the augur bore in the keel and round
all, should be the first made fast, that the other seizing rope
(which we shall suppose to have been made fast to the ring
in the stem) may, in passing through the eyes on the sling,
take in the surrounding rope betwixt the two eyes, which
will thereby prevent the surrounding rope from slipping to
either side of the cask.

The seizing rope, having passed through the eyes on the
sling, is then to be passed on through the ring in the keel,
and thence back again in the same manner, through the
eyes on the sling on the other end of the cask, to the ring in
) the bow; and lastly, the seizing rope is to be brought di-

rectly from the ring in the stem to the ring in the keel, by
which it will cross the cask at the bung or middle part of it :
the other cask and cork aft are to be secured in the same
/ nianner.

The preparation will be completed by attaching a bar of
lead or pig-iron, of about two hundred weight, to the keel
within side, by means of the ring-bolts in the keel or other-
wise.
Vanation ia The same plan may be executed with equal effect, and
Ike plan. nearly with the same expedition, by the following alteration
and arrangement.

Instead of one large cask, two less ones may be used in
each end of the boat.

These are to be laid in lengthwise, fore and aft, in the
bo^t, alongside of each other, and both together ought to fill
the width of the boat.

These must also be furnished with slings on each end,

and

SHIP*S LIFEBOAT. j^$

«nd with two eyes on each sling, and these eya* so placed as
to be about two inches above ths horizontal diameter of the
cask, one eye being on each side of the cask when the sling
is put on.

The seizing-rope, being now made fast to the ring in the *
stem, istobepassedthroughtlie eyes on the slings on oneside
of the cask, then througli the ring in the keel, and so back ^
again through the eyes on the slings on the other side of the
same cask, to the ring in the stem. The rope is then conti-
nued on till it has passed in the same manner on both sides
of the adjoining cask, and the last turn is to be made directly
from ringbolt to ringbolt, passing over and above the sur-
rounding rope, which will thereby be brought down in the
middle betwixt the twd casks, and made closely to compress
them on each side.

The same process is to be followed as to the casks aft,
where the dimensions of the boat will admit of it, and where
otherwise one large cask athwart ^hip may be used, as in
the plate, fig. 5. It was in this manner that the experiment
at Leith, hereafter to be detailed, was made, and all the
cork that was used on that occasion was about one hundred
weight put into the narrow part of the boat aft, in order to
raise a common porter cask placed above it to a convenient
height. The preparation of the cork bundles in this case
will differ somewhat in their shape from those in the former
plan, but as the purpose of them is the same, namely, t<>
fill up the vacant spaces betwixt the cask and the boat, a
particular description of them seems quite unnecessary;
only it may be observed, that as the diameters of the casks
forward are considerably less than that in the former plan,
so much of the cork ought to be placed underneath, as may »,0\f, Htff![>
serve to raise the upper side of the casks about four inches
above the gunwales, it being evident, that the higher they
can be raised with sufficient security, the more effectually tiil
possibility of overturning will be prevented.

The same quantity of ballast is to be used in this case atf
in the former, and is to be applied in the same manner.

With respect to boats of small vessels, a single cask for- Boats of smaU
ward and another aft, without any cork, will be sufficient, ^"sels.

Each cask to be about the size of a hogshead, and to be

set

Advantages of
timely prepa-
ntioQ.

qA ship*s lifeboat.

set on end, or leaning obliquely towards the rings in the
stem and stern, to which they are to be secured, and at the
same time to two other rings placed in the keel, proper for
that purpose : these caskJ^, from their position and power,
would effectually prevent sinking or upsetting: and as the
crews of such vessels are few in number, their boats might
support them safely through any breach into shallow water.

The foregoing plans are founded upon unquestionable
principles, and constructed according to a regular method.
They keep in view the difficulties to be encountered, and
provide against them by making a few necessary prepara-
tions in due time. Were this attended to, all the confusion
and embarrassment which arise from sudden alarm, and
the distress that must attend a total want of suitable means,
would be prevented, and an encouraging prospect of safety
held out even in the most perilous situations.

The want of timely forecast, and the neglect of means
that were in our power, never fail to occasion the bitterest
self-reproach, and the most painful vexation, whenever we
are overtaken by misfortunes, which a little prudence mighi;
have prevented.

Having however but too much reason to apprehend, that
such prudential provisions as have been stated will still be
neglected, in spite of every suggestion and consideration
that can be urged, I shall now propose a third plan.
Though inferior to the former, as a ship with jury masts, torn
sails, and a temporary rudder, is to one in perfect good con-
dition; yet, considering that this inferior plan, like the dis-
abled ship, may gain what was despaired of, and save what
was given up for lost, I proceed to state it :
Casks alone. This plan will consist in the application of casks only.
These, if stowed closely and so as to fill up as well as pos-
sible one third part of the boat forward, and one third aft,
would effectually prevent the boat from sinking or over-
setting.

Upon this plan, in order the better to secure and com-
bine the casks, the end of a. sail should be in the first place
thrown into the bottom of the boat, and the c&sks being
stowed upon it, the other end of the sail should then be dou-
Jbled over all : the seizings are then to be made through

holes

A third plan
suggested.

9S

holes struck any where through the bott<5iii and sides, wheiC-
ever the passing of a rope may be found necessary, or of any
use for confining the casks.

The constant and general idea, that the utility of every Holes in th«
boat depends upon the tightness of her bottom, *^nd her j^^^^j ^^^^^^^
completely resisting the admission of water, opposes itself tageous*
•trongly and almost irresistibly to the directly opposite
idea, that water freely admitted could do no injury; nay, so
strong is the received opinion, that it may be very difRcult
to persuade some, that large openings in the bottom would
prove a real advantage ; it is however undoubtedly true, that
in the present plan this would really be the case.

It is therefore very material to observe, that neither the
number nor the size of the holes struck through is of any
consequence, as to the water in the boat ; on the contrary,
they would be so far from being detrimental, that, to a cer-
tain extent, they would be of advantage, as they would serve
to discharge, in proportion to the buoyancy contained, what-
ever top-water might be withinside, above the level without,
and which the boat would otherwise retain as a load and dead
weight, if she were every where perfectly tight: whereas, in
proportion as the buoyant power operated in raising her, the
top-water would instantly subside through the holes in the
bottom, and thereby render her more lively, and to swim
higher out of the water.

From not attending sufficiently to the fact now stated, it
has probably happened, that the plan we are at present de-
scribing has never been attempted; but whoever will take
the trouble to consider the matter a little may soon be con-
vinced, that they may, without scruple or hesitation, make as
many holeSi and of whatever size, as they may judge neces*>
tary for passing ropes, wherever they can serve for efFectu-
filly securing the casks in their places.

The only point chiefly to be attended to is never to attach The fastenings
ropes to any tender part of the boat, such as the gunwales or ^° 'j^ applied
thwarts, but to such parts as possess the greatest strength, est parts.
and in which entire confidence may be placed.

As the largest boats have strong timbers, this plan might
probably succeed best if applied to launches and long-boats.

Snaall anchors that have iron stocks, and which could be Ballast.

laid

96

Holer.

BuAyancy of
•stslu.

ship's LIFEftOAT*

laid in the bottom of the boat, would serve for ballast ;i
though probably ballast in large boats would not be very
necessary.

The holes to be struck through may be pierced with a
marling-spike and mallet betwixt the timbers.

The power and effect of empty casks is well known, the
application of them being a common expedient, used almost
every day for the purpose of floating stranded or bilged ves-*
sels of great burden. How easy then it must be, by the
same means, to render a boat buoyant to any degree that
could be wished, may be abundantly evident to every per-
son not obstinately blind to undeniable fact.

The thing is so self-evident as to require no proof, that, if
both ends of the "boat be tolerably filled with empty casks,
ishe will not only thereby be secured against upsetting or
sinking, but will be rendered extremely buoyant, provided
the casks be effectually secured in their places; ai^d in full
proof of this fact, the experiment hereafter to be narrated
was made almost entirely with empty casks.

The inventor having little hope that the far better and
more eligible plan by timely preparation will be adopted, is
the more solicitous to gain attention to this third mode, by
means of casks only, because necessity, Vvhich is often the
mother of persuasion as well as of invention, may compel the
unfortunate mariner to have recourse to it.

Seamen being above all others expert in the use of ropes,
and expeditious in making secure seizings, which is the
Ijreat and only thing wanted, the inventor begs leave confi-
dently to affirm, that whenever it shall be tried it will be
found perfectly safe and successful.

Let therefore no scruple or hesitation be ma<le in striking
boles through the boat, any where, and of any number c:
size that may be found necessary for passing ropes for the
effectual confinement of the casks. This plan will apply not
to one boat onli/i but to every boat in the ship, provided there
be a sufficiency of casks on board.

If then the two great points upon which 1 set out,
namely, the powerful buoyancy of casks, and the peculiar
expertness of seamen in every operation where ropes are to
be used, be duly considered, they will sufficiently vindicate

and

SHIP^S LIFEBOAT* 97^

•nd verify all that 1 have stated ; and unless the one or the
other, or both, (that is, the power of casks, and expertnes«
of seamen) can be shown to be false assumptions, the con-
clusions which 1 have drawn can neither be denied nor re*
sisted.

Observations and Remarks relative to the foregoing
Plans.

1. — From the detail in the description it may be alleged, Observation*,
that the situation would not admit of so much time as the Time,
preparation would require. *

It is granted, that in some cases this might be true, if
nothing had been done before-hand; but surely such neglect
ought by no means to be imputed as any defect in the plan,
but ought to be ascribed to its true cause, the remissness of
those who would give themselves no trouble to avail them-
selves df it.

Slings fitted to the casks, two additional ring bolts, two
auger bores, and the requisite quantity of cork, are all
things so trivial and so easy to be provided, that to be with-
out them must appear an unpardonable neglect ; and, if
these were in readiness, the short space of ten minutes would
be quite sufficient for laying them in their places, -and s«J*
curing them.

It is evident to demonstration, or it might be easily proved
by experiment, with respect to the first two methods stated,
and where the necessary provisions had been made, that the
whole could be executed in ten minutes, and therefore any
objection in point of time can have no place.

2. — When there is a prospect of the ship holding toge^ The boat mar
ther for some time, the boat may be kept in readiness and be serTed on
in reserve, or may be served on shore by a rope, and hauled ^^'d't^^ti^^ff
off again, as often as occasion may require; and if to be again,
hauled off, it might be a necessary precaution to pass a rope
round her lengthways to assist the ring bolt in the bow, and
in every case the attachment and connection of the boat
with the vessel ought to be well secured till the znomentsthc
js to be cast off for the shore. ^ r

Voi.,XXlX— June. ISIK H 3.— It

gij ship's lifeboat.

May be got 3.— It is of no consequence in what manner this boat it

any hoV^^'^"^ ^^ ^^ S^^ '"^** *^^ water, whether after-end or side, by means
of handspikes or otherwise, as no water can hurt her.
though it might be more desirable, if it could be done
without tilling her in midships, as in that case she might
be conducted through very heavy seas without tilling at all,
or receiving more water than might be easily baled out.
No matter howr 4,^ — It is material to remark, as it may not generally be
are in water, attended to, that the plan always supposes the midships to
be full of water ; but that the requisite buoyancy of the
boat is not injured by that circumstance, nor will the addi-
tion of people, in so far as they are immersed in the water,
prove any additional burden; this will be perfectly clear to
all who understand this part of the subject, however impro-
bable it may appear to others, and the remark serves to
show, that it would be a good rule, in such circumstances,
for the men to keep themselves immersed in the water in
midships as far as possible.

, The idea of placing men in the midships of the boat,
while at the same time it was full of water, would probably
gtfirtle a landsman not a little; such therefore may be told,
that every lifeboat is supposed full of water, and that to
( imagine there could be any man in one with a dry thread

aboi^t him would argue a total ignorance of the matter,

5. — It is to be kept in mind, that the danger is always
supposed to be extreme, and that the present plan affords
th^,^ only possible chance of saving life; therefore whatever
hardship or difficulty there may be in putting it in execu-
tion is entirely out of the question ; any other view of the
subject is altogether foreign to the purpose.
Casks superior G. — If any are of opinion, that cork ought alone to be
t*cor . used for buoyancy, there can be no doubt of its answering

the purpose perfectly; at the same time the author is of
opinion, that a combination of cork and casks would be
found more convenient, and in some respects preferable.

Water casks would always be at hand, and, to save the
iexpense of cork, might on that account be preferred by
MHne ; but independent. of this consideration, casks are by
wat^re than one half lighter than their bulk of cork, and
'•'. I thereby

ship's lifeboat. 99^

Ihereby more than a double advantage in favour of buoyancy
is gained by using them.

There is but one objection to the use of casks, and that ^

is, that they may be stove in ; but if the great strength
which they possess from their construction be considered,
and at the same time that they are strongly defended by the
boat, this objection must appear of no moment at all.

7. — Every boat, prepared as has been stated, is fit to carry Proportion of
men equal in weight to something more than one third of ™^^y* ** ^
the boat's whole burden, and one of eighteen feet in length
can carry from fourteen to sixteen people, and have suffi-
cient room for working a pair of oars, which ought by all ^*"» '[*°J»

. 3 * should be sh«it»

means to be short ones.

The disadvantage of working long oars upon a low gun-
wale, and in a high running sea, is too obvious to need any
thing more than to be just mentioned.

8. — As all depends upon the points of fixture, too much The fixing
attention cannot be paid to their sufficiency, and though *^°"''* ^* ^•^
those stated in the plan are judged to be perfectly adequate
to the purpose, yet any person, wishing for more, may add
them at pleasure, by rings of rope in the stem and stern-
posts, as in the Greenland boats; by more rings in the
keel ; or, in addition to the seizing ropes, a netting of small
rope may be made to cover the whole foreward, and another
such may be applied in the same manner aft, and by these
means every possible security that can be desired may be
obtained.

9.— It is material to observe, that no dependence ought The thtrarts ft

to be placed on seizintrs connected with the thwarts or g'jnYa'es ua-

, , . ^ , . , , - . safe tor lb»«,

gunwales, unless it were only as aids to the points of mam

dependence. The gunwales, more than any other part

of the boat, are liable to damage, and may very possibly

be injured in hoisting out, or before getting clear of the

vessel.

The two auger bores in the keel are infallible holds ; The auge;^
easy access may be had to them while the boat is on deck, jj^ ^" ^|^*
and a rope may be passed through them in a moment.
This seizing, beside the security it affords for confining
the buoyancy, adds considerably to the strength of th^ boat,

H 2 %U

100 «rip'8 tirEBoAT.

and therefore ought to be preferred to any other mode of
fixture.

lO.w-No rule can be laid down that will fit all boats, as
to the precise quantity of cork, or size of casks, their shape
and dimensions being so various; but from the general rule
that has been stated, and the purpose to be served, every
man may easily adjust his apparatus to his boat, or make
such little alterations iu the boat as may be found couvenient
or necessary.
A sail advan- 1 1. — No sail can hurt this boat, as it is supposed she has
tageous, only to go right before the wind, and therefore a sail may

be used with very great. advantage. This would render
oars unnecessary, and would be infinitely preferable. It is
almost needless to add, that the boat could be steered in
midships.
Disadvantage!, 1 2. — The great benefit derived from the common life-
of the common boats is well known, and universally acknowledged; but
they are very far from being adequate to the calamity they
are intended to remedy. Their number comparatively is
very few, and the sphere of their operations extremely li-
mited. In darkness by night, and in thick snow by day,
when their aid is most wanted, they are of no avail. Storms
may blow, and sometimes have blown so hard as to defeat
their utmost exertions ; and even in the most favourable
cases, they require a considerable time before they can reach
the wreck ; in the mean time the vessel may be dashed to
pieces, and all hands lost.
Superiority of '^^^ ^^'*y Preeminent advantage of the shipboat in these
fhe present, and several other respects is very conspicuous. This boat
is wherever the ship is, and recourse may immediately be
had to her ; is of equal utility by night as by day, and in
- the thickest as well as in the clearest weather; and while
the lifeboat, with extreme slow progress, must be impelled
{(gainst wind and sea by a force superior to both, the ship-
boat has only to drift with ease before the storm,
Tiief principle IS.—As it may serve to gain confidence with those who
ihe^same in Q^e not otherwise qualified to judge of the plan, it may be
observed, that the shipboat i.s prepared upon the very same
principles as the liffeboat, and that these principles are ap-
plied to-a^reat^r ad^antagte in the former than in the latter.

. ' The

boifl.

ship's lifeboatV 101

The quantity of buoyancy in the shipboat, being, consider-
ably more in proportion to her size, and being carried to a
greater height, gives more security against oversetting; an4
if to these advantages there be added the far greater one of
having only to drift before wind and sea, no shadow of'
doubt remains of the success of the shipboat over that of
the other.

Lastly. — This plan carries with it the very strong recom-The plan ad

mendation of private interest as well as of public utility, vantageousto
* , ... private interest,

Suppose a ship to be riding in an open bay or roadstead,

a storm comes on, and, if in winter, a long dark night is soon
5 to foUov. In this situation the mariners, being extremely
doubtful whether the vessel could hold it out over the night, «.
and terrified at the awful prospect of being thrown, as it
were, blindfold into the most perilous of all situations, the
determination would most undoubtedly be to cut and let the
ship run on shore while there was light, as giving the only -^

chance for saving life.

The same determination may be taken in hopes of escap-
ing by favour of a falling tide, and in both cases lives, ship,
and cargo may be all lost, as has certainly very frequently
happened. Whereas could safety be ultimately relied upon as it would en*
from the boat, the ship would be allowed to ride so long as ^**"^^S*^ n^®'^
anchors and cables could hold her ; and in the mean time ship in danger.
the storm might abate, the wind might shift, or her tackling
might prove sufficient to ride out the storm, and thus lives,
ship and cargo would all be safe.

, ^ In every situation the prospect of safety by means of
the boat would prevent every precipitate measure, and eiT-'
courage men to make those exertions for saving ship and
cargo, which are not to be expected from men despairing of
life.

In the foregoing plans there is nothing that can be reck- It is simple, &
oned complex, nothing that requires nice adjustment, or ^f "^^^^j^ction-
doubtful and precarious effect. They are unquestionable
in principle, simple and easy in execution, and absolute in
security ; and if the nece:<8ary previous preparation, which"
is very little, has been made, they will be found as expedi*
tious as any emergency can require. They have been*
proved by experiment as far at circumstances would per-

109 IHlP'f tIFEBOAT.

mit» and have received the unqualified approbation of
naval men of the greatest experience, and of the first re-
spectability.

These are the solid grounds upon which they are offered
to the public in e:eaeral, and most earnestly pressed upon
the attention of seamen in particular.

The plan having been commmunicated to hundreds of
seafaring men, they have always given it their ready and
entire approbation ; hence it is hoped, that every seaman
from his own knowledge and experience, without any doubt
whatever, will, upon considering the subject, be folly con-
vinced in his own mind, that the scheme is perfectly prac-
ticable, and if adopted, would be attended with the happiest
effect.

Substitutes and Expedients which may he found useful.

Substitutes. 1^"^ — ^^ so much cork was made up in canvas as would

serve to go quite round the boat withoutside, and reach from
the top of the gunwales to about fifteen inches downward,
and of one foot in thickness; the same might be attached
to the boat, and would render h^r extremely buoyant. Tkis,
' together with ballast, and a small quantity of cork within-

side, would produce a perfect lifeboat, upon almost the very
same plan as the present lifeboats.

The cork might be made up in so many separate parcels,
(netted in small rope,) as was found convenient to be at-
tached to a strong rope going round the gunwale, and to
another such which ought exactly to fit the girth of the boat
where the cork reached to below,

As the cork would only press upwards, and always against
the bottom and sides pf the boat, it is evident, that, if the
lower rope fitted tightly, the cork would keep its place; and
in order to secure that point a few turns of rope passing
from the lower edge on the one side over the kieel to the
lower edge pn the other side would fix it completely. A
» very few seizings attached to the gunwale rope passing from

the one side to the other would be quite sufficient.

The separate parcels must be furnished with loops or
ends for attaching them to the main ropes, and to one ano-?^
then

9**-^eyer^^

ship's lifeboat. J 03

t. — Several ringbolts might be put into the keel within-
$ide, and ropes, single, double, or treble, might be passed
through these rings before laying in the buoyant materials,
and then these ropes might be brought round the whole
contents and made fast.

3. — It frequently happens that seamen, after they have
gained the shore, find they have only escaped one death to
perish by another still more miserable. "* '-

Drenched in water, chilled to the heart with cold, worn Dry clothing
out with fatigue, and exposed to all the severity of inclc-
inent weather, without shelter or succour, it is impossible
but that the remains of life must soon be extinguished.

In this situation, and it is far from being uncommon, dry
clothing would be as precious as life itself, and it might be
had by the following expedient: —

Let a leathern bag be made for containing some shirts, a
waistcoat or two, and two pair of drawers, all of flannel.

Let this bag be made of a length and size convenient for
the purpose, and for tying round under the arm-pits.

This would serve the purpose of a cork-jacket in the n^a^^e toan-
water, and prove a second time as life from the dead, by af- p^se ©fa cork
fording dry and warm clothing upon gaining the shore. jacket.

By this expedient every man may be made a swim-
mer, and sometimes one man by smimming has been the
means of saving the whole ship's company.

It may be proper to observe, that the larger part of the
bag should be placed high upon the breast, and the other or
back part no higher than the armpits, as in the act of swim-
ming the back part of the shoulders is little more than just
covered with the water.

The bag must be perfectly water-tight, and only mode-
rately filled; both ends of it may be left open to be closed
with a tight seizing of small line.

The expense of this preparation would hardly be five
shillings.

4. — If it were intended only for swimming, a neat and
commodious preparation might be made with cork covered
with thin leather*, to be applied in the manner which has
just been described.

• 1 conceive flannel would be preferable. It would b« less cold, and
not SQ much affected by soaking ia water. C.

It

104 imp'* JLIFEBOAT.

, It might be fitted on with clothes or without in half 9

minute, and made fast by a knot or clasp on the breast ;

three pounds of good cork would be sufficient to support any

man, and the expense no more than in the former case.

Alinemight 5. — Another expedient bids fair for obtaining a speedy

on shore by a conaa^unication betwixt the ship and the shore, by means of

kite a kite.

It is the property of this machine, to ascend in propor-
tion as the cord is spared off.

To manage this, and to bring the line within reach on
shore, let a piece of light wood, about the size of a small
handspike, be attached to the line, about twelve fathoms
from the kite; the line to be fixed to the forepart of the
stick, and so as to pull only there, and then being slackly
laid along the stick, made fast to the other end : by this
means the kite would be prevented from rising higher, and
would, at the same time bring the line to the shore from the
ship, and by this small Une a rope might be hauled from
the ship by any spectator on the shore.

A silk handkerchief, and a piece of wooden hoop, might
«oon furnish a kite,
crby a spread 6. — Sometimes people are seen to perish, where those on
'* shore, and those on the wreck, are almost within grasp of

each other.

In this case, if there happened to be a mast standing, a
common ensign made fast to a stick, just strong enough to
keep it spread, uid quickly spared oft' from the mast head,
would probably reach the shore without touching the water,
or at least drift on shore with a small line attached to it.

No experiments having been made upon these substitutes
and expedients, they are barely mentioned, as things that
might possibly succeed, and are thrown out as hints for
others to improve upon, after much consideration on my
part.

invention of After this follow testimonies of approbation, from which

thelifeboat, j^ appears, that a boat prepared according to Mr. Brem-

ner's plan, when overset by ropes applied for the purpose,

righted herself immediately when these ropes were removed.

The plan was not copied {torn that of the lifeboat, as it was

communicated

SCALE OF THE BAROMETER* 105

communicated to Lord Melville, when Treasurer of the
Nayy, in 1792: whether the lifeboat were borrowed from it
is more questionable.

Mr. Bremner also takes this opportunity of asserting hia *"* of locate
claim to the invention of applying locks to cannon, >vhich he
communicated to the lale ^ir Charles Douglas so long ago
as the year 1768.

III.

On the Scale ofth^ Barometer, and the Consiruction of an ♦

Airptimp for procuring a perfect Vacuum, In a Letter
from a Correspondent,

To Mr. NICHOLSON,
SIR,

JL FEEL much obliged by the insertion of ray paper on
the Airpump, in your very valuable Journal. Should the ^, ^^ *-*
following hint, respecting the construction of the barometer,
(which is at least new to myself,) appear to be worthy the at-
tention of your readers, it is much at your service.

In Mr. Dalton's Meteorological Observations, page 7, obser^ationsof
where he is speaking of the barometer, I find the following the scale of tke
remark: *'The scale in strictness ought not to be full *'*^™^®''
** inches, but something less, owing to the rising and falling
«< of the surface of the reservoir. If the tube have a bulb,
** then the area of the surface at the top of the column, di«
" vided by the sum of the areas of the top and reservoir,
*' will give the part to be dedufted; but if the tube be
** straight, then the whole area of the reservoir, lessened by
** the area of the glass annulus, made by a horizontal sec-
** tion of the erected tube, must be used as the denomi-
" nator of the fraction ; hence, if the fraction be ^V* then
•* the scale of 3 inches must be diminished by half a tenth."
At page 9 the following observation occurs. "With re-
«* spect to the barometers at Kendal and Keswick, they
" were both clear of air and moisture, and exhibited the
•* electric light in the dark. The scales were both full
** inchesj and therefore the variations were somewhat greatef

♦Vthai^

106 SCALE OF THE BAROMETEE.

•* than the observations denote them. About ^V should
** have been allowed upon them." Not to mention the dif-
The proper ficulty of obtaining the exact areas of the top of the column,
correctiofi sel< j^^^ of the bulb, the latter of which is continually varying
on account of its spherical form; it appears from Mr. Dal-
tons second observation, that philosophers do not always
make the necessary corrections, even when they have suf-
ficient data to do so.
barometer The barometer which I generally make use of has a scale

scales for this ^^'^^^^ ^^ ^^^ bulb, as well as one at the top of the column,
purpose. These scales are both divided into equal portions of an inch :

in making an observation, therefore, with this barometer, I
have nothing to do, but to take the height of the mercury
in the column, and of that also in the bulb*, and by sub-
' tracting the latter from the former, the true altitude is im-

mediately obtained. In the annexed 6gure, pi. IV, fig. 1,
1 have given a sketch of an improved construction of a ba-
rometer, upon the same principle.
The same ef- This barometer consists of a tube, bent into the form of a
fie scale. siphon, and hermetically sealed at the largest end, which

must exceed 31 inches. The other end is open, and 4 or
5 inches will be a sufficient length for it. If both the legs of
the siphon be of equal size, it is evident, that, when the
mercury rises one inch in the largest leg, it will fall one
inch in the shortest; and vice versa. The scale is to be 31
inches in length, and graduated in the usual manner at
the top ; but it must be movable, so as to slide freely,
upwards and downwards, in a groove, which is to be set in
the frame of the instrument. When we wish to take ar^
observation, we have only to fix the bottom of the scale
in the same horizontal line with the surface of the mercury
in the open tube ; and the height of the column may be in-
stantly noted, as with the common barometer; only in tliis
case, no correction will be necessary for the rising or falling
of the surface of the reservoir. An index should be affixed
to the lower extremity of the scale, to facilitate the adjust-
ment of it to the height of the mercury; and another
moyable index, with a vernier scale, may be added to the

• 9oth the scales are graduated from the same point.

top,

JLIRPUMP FOR A PERFECT TACUUM. 10/

top. When themfrcury rises 1 inch in the common baro-
meter« it will rise only fan inchin this, on account of the de-
pression in the other end, which will also be equal to |^ an
inch: it is however evident, that this diminution of range
cannot at all affect the sensibility of the instrument ; as it
will be increased in an equal degree, in the opposite tube.
But it is by no means necessary, that thelegsof the siphon
should be of equal diameter; although I have supposed
them to be so, in the present instance, in order to make the
action of the sliding scale more apparent. The scale may
be affixed to any common barometer, having either a bulb,
or an open reservoir; as will be evident, by inspecting the
figure.

The note which is added to my paper on the airpurap Airpump.
is perfectly just. I had however purposely avoided mak-
ing use of the expression a ** perfect ractmm" ; and sub-
stituted that oi exhavstion, in the room of it: meaning, that
provided the construction of the pump were perfect, there
would be no limit to the exhaustion it was capable of pro-
ducing, i. e. that as long as any air remained in the receiver,
a portion of it might still be expelled, by continuing the
action of the pump; and although, strictly speaking, this is
not producing ii perfect exhaustion, yet it may be carried
on in infinitum*. 1 was so well convinced of the impossibi-
lity of obtaining a perfect vacuum, by this, or any other
pump, that it was my intention to have added a few words
on this subject, and on the only means, by which, I con-
ceive, it may be procured. The vacuum of the baro- Toricellian va-
meter cannot be considered as perfect, even when air and ^""™*
moisture are entirely excluded; on account of the atmos-
phere, formed by the evaporation of the mercury itself, as
was ascertained by Lavoisier, (Kerr's transl. p. 59, Ed. 3,)
and also by Dr, Priestley. (See his Experiments Vol. 5,

• Let us suppose the capacity of the barrel to be greater than that of
^ the receiver. By the first stroke of the piston, a quantity of air greater
than the half will be taken away : by th« second stroke, more than half
ef the remainder will be removed, and so on : in this case, (hen, it is evi-
<lent, that if the action of the pump be continued, there will at last re*
inain a quantity less than any that caii be assigned. This is approaching
f€»y nev to perfection,

p. 22^.)

JOS

AfRPUMP POR A PERFECT VACUUW,

Airpamp for
» perfect Ta-

p. '2t5.) It may not be amiss to obserre here, that it seero*
necessary, that a correction for this should be made, in
taking observations with the barometer ; as the mercurial
atmoephere will react upon the surface of the top of the
column, and prevent it from rising to the full height, ta
which it would otherwise attain.

By the following means, a perfect vacuum, I believe,
may be obtained. Let A B (fig. 2) oe a tube of metal,
ground so as to be perfectly cylindrical in the inside: let
C C be the piston-rod ; and D the piston, which is solid ; and
Jet abeasmall metallic valve, opening outwards: also let the
concave and convex surfaces of the barrel, and of the piston,
be ground accurately to each other. Let us imagine the
piston to be at the top of the barrel, and that all the air is
expelled by means of the valve a: if the piston be now
forced downwards, the space above it will be a perfect va^
cuum; at least with respect to air, and all evaporable
fluids. The valve might be placed in the piston, as re*
presented by the dotted lines at b ; and in this case the
one at a would be unnecessary. The action of this pump
might be rendered more secure, by closing the bottom of
the barrel, and inserting in it a metallic valve, opening out-^
wards; and by making the piston rod to move in a collar
of leathers: the piston also and the bottom of the barrel
might be ground to each other. By these means, there
V would be but little danger of any air forcing itself into the
vacuum, which would be perfect above the piston, and
invhich some Tiearly, if not quite, so below it. This addition is shown by
pcriments the dotted lines. If the barrel were made of glass, we
should then have it in our power, to observe the appearance
of the electric fluid, in a perfect vacuum ; which, I believe,
has never yet been the case. The bottom of the piston also
roi.^ht be formed of different metals, and exposed to the
action of a burning glass, or of a galvanic battery. If
any elastic fluid were generated by the process", it woul4
be easy to collect and to ascertain its nature. Many other-
solid substances might be acted upon, by fixing them ac«s
turately into the bottom of the piston, so as to form a part
l^f it ; and by using the same agents, as in the former case.
The principle upon whi9h this pump is constructed I

cosjfSid??

•light be

FORCING HOUSE tOR GRiPEt* {09

consider as perfect; its application is by no meatis so: it
may nevertheless be a useful hint to those, who are engaged
iu very refined experiments on the nature of the metals, &c.
It would be less troublesome to construct, and perhaps more Another con-
applicable to most purposes, if made after the following ^J^^"^^'^*"^*^
plan. Let A B be a glass cylinder, D the piston, and E E pose.
a plate of glass, large enough to cover the top of the barrel.
When this instrutnent is to be made use of, let the piston
be forced upwards, so as to project about a line or less
above the cylinder; let the glass plate E E (which must be
well ground to the top of the piston) be laid upon the pis-
ton, and let it then be drawn downwards; the plate will be
kept in its place, by the pressure of the atmosphere, (or
other means may be made use of to keep it more secure) and
the vacuum will be perfect, as in the former case. The glass-
E E may be made of a piece of common plate glass, if truly
ground; and the focus of the lens will easily be directed
through it, so as to fall upon the bottom of the piston.

I am, Sir,
Your obliged and constant reader,

L. O. C,

IV.

A Description of a Forcing House for Grapes; with Ohser*
vations on the best Method of constructing them for other
Fruits, By T. A. Knight, Esq. F, R, S, ^c*

S

O much difference of opinion prevails among gardeners Construction
respecting the proper forms of forcing houses, that two are o{ forcing
rarely constructed quite alike, though intended for the f^®"'*^ *'*'
same purposes; and every gardener is prepared to contend,
that the form he prefers is the best, and to appeal to ihet
test of successful experiment, in support of his opinion.
And this^ he is generally enabled in some degree to do»
because plants, when properly supplied with food, and
water, and heat, will succeed in houses, the forms of which
ar« very defective ; and proper attention is not often paj4

• Tra'^.s. of the Horticultural S©c. Vol. I, p 9P -^ *♦

by

IIQ FORCING HOUSE FOR GRAPES.

by the gardener, when his prejudices satisfy him, that his
labours cunnot be successful. It is, however, sufficiently
evident, that, when the same fruit is to be ripened in the
same climate and season of the year, one peculiar form must
be superior to every other, and that in our climate, where
sunshine and natural heat do not abound, that form, which
admits the greatest quantity of light through the least
breadth of glass, and which affords the greatest regular heat
with the least expenditure of fuel, must generally be the
best : and if the truth of this position be admitted, it will be
very easy to prove, that few of our forcing houses are at pre-
sent ever moderately well constructed. I therefore think,
, that, if plans and descriptions of such forcing houses, as
theory and practice combine to prove to have been properly
constructed for the culture of every different species of
fruit, were published by the Horticultural Society, much
useful information might be conveyed to the practical gar-
dener: and under these impressions T send the following
description of a vinery, in which the most abundant crop*
of grapes have been perfectly ripened within less time, and
with less expenditure of fuel, than I have witnessed in any
other instance.
Best indina- It is well known that the sun operates most powerfully
in the forcing house, when its rays fall most perpendicularly
on the root : because the quantity of light, that glances off
without entering the house, is inversely proportionate to the
degree of obliquity, with which it strikes upon tb« surface
of the glasrs; and it is therefore important to every builder
of a forcing house to know by what elevation of the roof,
the greatest quantity of light can be made to pass through
it. To ascertain this point, i have made many experiments,
and the result of them has satisfied me that, in latitude 52,
the best elevation is about that of 34 degrees : and relative
to that elevation the position of the sun, in different part«
of the year, will be nearly as represented i n the annexed sketch,
pi. IV, fig. 4, which is taken from the vinery I have mentioned.
About the middle of May, the elevation of the sun will
nearly correspond with that of the asterisk A, and in the be-
ginning of June, and again early in July, it will be vertical
at B, and at Midsummer it will at C be orjly six degrees

from

tion of the
glass.

FORCING HOUSE FOR GRAPEI. Ill

from being vertical. The asterisk D points out its position

at the equinoxes, and E its position in midwinter.

In this building, which is forty feet long, and is heated ^'"*»

by a single fire place, the flue goes entirely round without

touching the walls; and in the front a spaceof two feet is

left between the flue and the wall, in the middle o^" which vlne!.''^'^*

space the vines, which are trained to the roofs, about eleven

inches from the glass, are planted ; and as both the wail and

flue are placed on arches, the vines are enabled to extend

their roots in every direction, while, in the spring, their , ^

growth is greatly excited by the heat, which their roots and i

stems receive from the flue. Air is generally admitted at

the ends only, where all the sashes are made to slide, to af- •^"''a^J™''*^

111 > . at the ends,

ford a free passage of air through the house, when necessary,

to prevent the grapes becoming mouldy in damp seasons.
About four feet of the upper end of every 3d light of the
roof is made to lift up, (being attached by hinges to the and by lifting
wood-work on the top of the back-wall) to give air in the j"^j^\°^^ ^"^ '^^
event of very hot and calm weather; for I prefer givinsf air
by lifting up the lights, to letting them slide down, be-
cause when the former method is adopted, no additional
shade is thrown on the plants. ^

The preceding plan is here particularly recommended for
a vinery only; but 1 am confident, that, by sinking the ^,1*^ P^*" *1^
front wall below the level of the ground, and making asmall pine stove.*
change in the form of the bark-bed, the same elevation of
roof may be made equally applicable to the pine stove, and
that no upright front glass ought, in any case whatever, to
be used ; for light can always be more beneficially admitted ^P"^^f ^^^^}
by adding to the length of the roof, if that be properly ele- ous.
vated ; and much expense may be saved both in the build-
ing, and in fuel. For forcing the peach or nectarine, I

must, however, observe, that I think any house of the ure- '^^'^^*^o"se
J. J. . 1 11 • , , ^ not fitted to

cedmg dimensions wholly improper; and I purpose to sub- the peach or

mit a plan for the improved culture of those fruits to the "*^**""«»
Horticultural Society at a future opportunity.

The vine often bleeds excessively when pruned in an im-
proper season, or when Accidentally wounded, and I believe Compo.ition
no mode of stopping the flow of the sap is at present known blpedrng^^f
t« jfardeners. I therefore mention the followinij-, which I *"^*^-

discovered

])|2 COMBINATIONS OF OXIMURIATIC GAS AVD OXIGEIT.

discovered many years ago, and have always practised witli
success : if to 4 pnrts of scraped cheese be added one part of
calcined oyster shells, or other pure calcareous earth, and
this composition be pressed strongly into the pores of the
wood, the sap will instantly cease to flow ; the largest branch
may of course betaken off at any season with safety.

Oft some of the Comhinations of Oximuriatie Gasand-Oxigen,
and on the Chemical Relations of these Principles to Jtv-
flammable Bodies. By Humphrey Davy, Esq. LL. />.
See.R. S. Prof. Chem. R. I. F. R. S. E*

1. Introduction^

^ . . . ^N the last communication which I had the honour of pre-
Oximunatic . ,T»ir^" > i • #.«

acidgasasim- sentmg to the Koyal bociety, I stated a number of facts,

pie substance, vvhich inclined me to believe, that the body improperly
called in the modern nomenclature of chemistry oximuri-
atie acid gas has not as yet been decomposed; but that it is
a peculiar substance, elementary as far as our knowledge
extends, and analogous in many of its properties to oxigen
gas.

My objects in the present lecture are to detail a number
of experiments, which 1 have made for the purpose of illus*
trating more fully the nature, properties, and combinations
of this substance, and its attractions for inflamtnable bo-
dies, as compared with those of oxigen; and hk-ewise to
present some general views and conclasions concerning
the chemical powers of different species of matter, and the
proportions in which they enter into union.

I have been almost constantly employed, since the last ses-
sion of the society, upon these regearclus, yet this time has
not beeo sufficient to enable me to approach to any thing
complete in the investigation. But on subjects, important

• Phil. Trans, for 1811,^. 1

both

COMBINATIONS OF OXlMURIATlC GAS AND OXIGEN. 113

both in their connexion with the higher departments of ^

chemical philosophy, and with the ceconomical applications
of chemistry, I tiust that even these imperfect labours will
not be wholly unacceptable,

2. On the Combinations of Oximuriatic Gas and Oxigen with
the Metals from the fixed Alkalis,

The intensity of the attraction of potassium for oximu- Potassium in-

riatic gas is shown by its spontaneous inflammation in this ^^"^es in oxi-

substance, and by the vividness of the combustion. I sa-

tistied myself, by various minute experiments, that no water ,,

is separated in this operation, and that the proportions of

the compound are such, that one grain of potassium absorbs

about 1*1 cubical inch of oximuriatic gas at the mean and forms a

temperature and pressure, and that they form a neutral "•"^'^^' ^°"*"
11-Li u \ p • t 1 poii"<i unal-

compound, which undergoes no change by fusion. I used, terable by fn-

in the experiments from which these conclusions are drawn, ^*^"»
a tray of platina for receiving the potassium ; the metal was
heated in an exhausted vessel, to decompose any water ab-
sorbed by the crust of potash, which forms upon the potas-
sium during its exposure to the atmosphere, and the gas-
was freed from vapour by muriate of lime. Large masses
of potassium cannot be made to inflame, without lieat, in >

oximuriatic gas. In all experiments in which I fused the
potassium upon glass, the retorts broke in pieces, in con-
sequence of the violence of the combustion, and even in two
instances when I used the tray of platina. If oximuriatic
gas be used not freed from vapour, or if the potassium has
been previously exposed to the air, a little moisture alwayg
separates during the process of combustion. When pure
potassium, and pure oximuriatic gas are used, the result, as thdsameas
1 have stated, is a mere binary compound, the same as mu/* "^""^^^ of pot-
riate of potash, that has undergone ignition.

The combustion of potassium and sodium in oxigen gas Potassium and
is much less vivid than in oximuriatic gas. From this sodium burn
phenomenon, and from some others, I was inclined to be- o^f«n than^
lieve, that the attraction of these metals for oxigen is feebler, oximurktk
than their attraction for pximuriatic gas. I made several ^***
experiments, which proved that this is the fact ; but before 1
enter upon a detail of them, it will be necessary to discus^

Vol. XXIX.— June, 1811. I ivor«

114 COMBINATIONS Of OXIMCRIATIC CJA8 AND OXIGEN.

ipore fully, than I have yet attempted, the nature of the
combinations of potassium and sodium with oxigen, and of
potash and soda with water.
When this Is I have stated in the last Bakerian Lecture, that potassium

na^UiTmetal ^^^ sodium, when burnt in oxigen gas, produce potash and
oxided. soda in a state of extreme dryness, and very difficult of

fusion. In the experiments from which these conclusions
are drawn, as I mentioned, I used trays of platina, and
finding that this metal was oxidated in the operation, I
heated the retort strongly, to expel any oxigen the platina
might have absorbed, and, except in cases when this precau-
tion was taken, I found the absorption of oxigen much
greater tlmn could be accounted for by the production of
Potassium and the alkalis. In all cases in which I burnt potassium or
sodium burned sodium in common air, applying only a gentle heat, I found
in common it,- i i i ^ -i i

air produce that the tirst products were substances extremely lusible,

brown, fusible ^^^^ of a reddish brown colour, which copiously effervesced
* in water, and which became dry alkali, by being strongly
heated upon platina in the air; phenomena, which, at aa
early period of the inquiry, induced me to suppose that they
were protoxides of potassium and sodium. Finding, in
subsequent experiments, however, that they deflagrated
with iron filings, and rapidly oxidated platma and silver, I
suspended my opinion on the subject, intending to inves-
tigate their nature more fully.

, . . Since that time, these oxides, as 1 find by a notice in the

•wnicii are per- ^ *'

•xides. Moniteur for July $th, 1810, have occupied the attention of

Messrs. Gay-Lussac and Thenard; and these able chemists

have discovered, that they are peroxides of potassium and

sodium, the one containing, according to tliem, three times

as much oxigen as potash, and the other 1*5 times as much

as soda.

When they I have been able to confirm in a general way these rntcr-

are formed on estinsT results, though I have not found any means of as-

jneuUicsub- ? . , , .i .-^ r> • . • i •

itances these certaimng accurately the quantity ot oxigen contamed m

are always ox- these pew oxides. When they are formed upon metallic
w' '^ * substances, there is always a considerable oxidation of the

metal, even though platina be employed. I have used a
platina tray lined with muriate of potash, that had been
fused; but in this caKe, though I am inclined to believe
^ that

I

COMBINATIONS OF OXIMURIATIC GAS AND OXIGEM^ 1|5

that some alkali was formed at the same time with the per-
oxides, yet I obtained an absorption of 2*6 cubical inches,
ia a case when 2 grains of potassium were employed, and
of 1*63 cubical inches, in a case when a grain of sodium was
used, but in this last instance the edge of the platina tray-
had been acted upon by the metal, and was oxidated*. The
mercury in the barometer in these experiments stood at
30*12 inches, and that in the thermometer at 62* Fahren-
heit.

When these peroxides were formed upon muriate of Their pmpef.
potash, the colour of that from potassium was of a bright
orange; that from sodium of a darker orange tint. They
gave off ox i gen, as Messrs. Gay-Lussac and Thenard
state, by the action of water or acids. They were con-
verted into alkali, as the French chemists have stated, by-
being heated with any metallic or inflammable matter.
They thickened fixed oils, forming a compound, that did
not redden paper tinged with turmeric, without the addition
of water.

When potassium is brought into contact with fused Action of p^
nitre, in tubes of pure glass, there is a slight scintillation fusedi*niire,
only, and the nitre becomes of a red brown colour. In this
operation, nitrogen is produced, and the oxide of potassium
formed. I thought that by ascertaining the quantity of
nitrogen evolved by the action of a given weight of potas*
siuni, and comparing this with the quantity of oxlgen dis-
engaged from the oxide by water, 1 might be able to deter-
mine its composition accurately. A grain of potassium
acting in this way, I found, produced only 0*l6 of nitro-
gen ; and the red oxide, by its action upon water, pro-
duced less than half a cubical inch of oxigen, so that it is
probable, that potash as well as its peroxide is formed in the
operation.

Sodium, when brought into contact with fused nitre, Action of ao.

• Messrs. Gay-Lussac and Thenard have stated in the paper above re- Potash and b*-
ferred to, that common potash and barytes absorb oxigen when heated, rytes absorb
It would seem, that the action of the fixed alkalis and of barytes on pla- oxigen whea.
tina depends on the production of the peroxides. I have little doubt, "«*'*^
but that these ingenious gentlemen will have anticipated this observation,
ill the detailed account of their experiments.

I )2 produced

Il6 Combinations of oximvriatic gas and oxioen.

dium on fused produced a violent deflagration. In two experiments in
which I used a grain of the metal, the tube broke with the
violence of the explosion. I succeeded in obtaining the
solid results of the deflagration of 4- a grain of sodium; but
it appeared, that no peroxide had formed, for the mass gave
no oxigen by the action of water.
Potassium When potassium is burnt in a retort of pure glass, the

tort of pure result is partly potash and partly peroxide, and by a long
glass, continued red heat the peroxide is entirely decomposed,

and in one of A grain of potassium was gently heated in a small green
containing ox- 8^^^^ retort containing oxigen; it burnt slowly, and with u.
igen. feeble flame; a quantity of oxigen was absorbed equal to

0*9 of a cubical inch ; by heating the retort to dull redness,
oxigen was expelled equal to 0"38 of a cubical inch; the
mercury in the thermometer in this experiment stood at 63*
Fahrenheit, and that in tlw? barometer at 30*1 inches.
Electrical de- , In experiments on the electrical decomposition of potash
poush^and^ ^ ®"^ soda, when the Voltaic battery employed contains from
soda. 500 to 1000 series in full action; the metals burn at the

moment of their production, and form the peroxides; and it
is probable, from the observations of Mr. Ritter, that these
bodies may be produced likewise in Voltaic operations on
potash, at the positive surface.
Supposed prot. In ray early experiments on potassium and sodium, I re-
oxides, garded the fusible substances appearing at the negative sur-
face, in the Voltaic circuit, as well as those produced by the
exposure of the metals to heat and air, as protoxides, and as
similar to the results obtained by heating the metals in con-
tact with small quantities of alkali.

. I have repeated these last operations, in which I con»
ceived that protoxides were formed.

. Potassium and sodium, when heated in glass tubes in
contact with about half of their weight of potash and soda,
that have been ignited, become first of a bright azure, then
produce a considerable quantity of hidrogen, and at last
form a gray coherent mass, not fusible at a dull red heat,
and which gives hidrogen by the action of water.

Whether these are true protoxides, or merely mixtures of
the alkaline metals with tiie alkalis, or with the alkalis and

reduced

I

COMBINATIONS OF OXIMURIATfC GAS AND OXIOEN. 217;

reduced silex from the glass, I shall not at present attempt -
to decide.

Potassium I find heated in a similar manner with fused
potash, in a tube of platina, gives, after having been ignited,
a dark mass that effervesces with water ; but even in this :
ease, it may be said, that the al'oy of platina and potassium
interferes, and that the substance i» not a protoxide, but
merely dry alkali mixed with this alloy.

As the pure alkalis were unknown, till the discovery of
potassium and sodium*, and as their properties have never
been described, it will perhaps be proper in this place to
notice them briefly.

When potassium and sodium are burnt in oxigen gas upon Description

platina, and heated to redness to decompose the peroxide of ^"^ properties
, . ^ . 1 , mt of the pure al-

potassiiira, the alkalis are of a grayish green colour. They kalis.

are harder than common potash or soda, and, as well as 1
could determine by an imperfect trial, of greater specific
gravity. They require a strong red heat for their perfect
fluidity, and evaporate slowly, by a still farther increase of
temperature. When small quantities of water are added
to them, they heat violently, become white, and are con-
verted into hydrats, and then are easily fusible and volatile.
When potassium or sodium is burnt on glass, freed from
metallic oxides, and strongly heated, or when potash or soda
is formed from the metals by the action of a minute quan«
tity of water, their colour approaches to white; but in other
sensible properties they resemble the alkalis formed upon
metallic substances; and are distinguished in a marked

* Stahl approached nearly to Ihe discovery of the pure alkalis He Stahl nearly
cemented solid caustic potash with iron filings in a long continued heat, discovered Ihe
and states, that in this way an alkali **valde causticum" is produced. ^""^ ^ *^*
Specim, Beck, part ii, p. 255. He procured caustic alkali also, by decom-
posing nitre by the metals. Id. p. 253.

1 find, that, when nitre isdecomposed in acrucibleof platina by a strong Affinity of
red heat, a yellow substance remains, which consists of potash and oxide potash for
of platina, apparently in chemical combination, The undecompounded J^^'^^^ip <^*
potash, which comes over in the process for procuring potassium by the
gunbarrel, is of an olive colour, and affords oxide of iron during its solution
in water. Pure potash will probably be found to hate an ?iffinity (or
pjany metallic oxides,

manner

m^ COMBINATfONS OF PXIMURIATIC GAS AKD OXIGEN.

manner by their difficult fusibility from the potash and soda
prepared by alcohol.
Wattr in the Mr. D*Arcet, and more distinctly Mr. BerthoUet, have
alKalis. concluded, that the loss ot weight of common fused potasli

and soda, during their combination with acids, depends
upon the expulsion of water, which Mr. BerthoUet has rated
at 13*9 per cent for potash, and Mr. D'Arcet, at 27 or 28
for potash, and 28 or 29 for soda *.

1 have stated in the last Bakerian lecture, that my own
results led rae to conclude, that fused potash containe4
about l6 or 17 parts in the 100 of water, taking the potash
formed by adding oxigen to potassium as a standard.

The experiment, from which 1 drew my conclusions, was
made on the action of silex and potash fused together, and
I regarded the loss of weight as the indicj^tion of the quan-
tity of moisture.
Water not yet 1 am acquainted with no experiment on record, in which

collected from ^^atep |,as been actually collected from the igrnited fixed

the Ignited al- . , "

kalis. alkalis, and this appeared necessary for the complete elucif

dation of the subject.
Experiment to 1 heated together, in a green glass retort, 40 grains of
•flfect this with potag},^ (that had been ignited for several minutes), and 100
^'' grains of boracic acid, which h.id been heated to whiteness

for nearly an hour. The retort was carefully weighed, and
connected with a small receiver, which was likewise weighed;
the bulb of the retort was then gradually heated till it be-
came of a cherry red ; there was a violent effervescence in
the retort, a fluid condensed in the neck, and passed into
the receiver. Whep the process was completed, the whole
Wat« 0»17? of the retort was strongly heated; it was found to have lost
6f grains, and the receiver had gained 5'S grains. The
fluid that it contained was water, holding in solution a mir
nute quantity of boracic acid, and when evaporated, it did
not leave an appreciable quantity of residuum*
Water from A similar experiment made upon soda, heated to redness,
but in which the water collected was not weighed, indicated
22*9 of water in 100 parts of soda.

* Annales de Chimie, torn. 08, page l90; or Journal, vol. XXVII,
page 31. -

or 0-19?

s«da 0-23.

COMBINATIONS OF OXIMURIATIC GAS AND OXIGEN. l]Q

It may be asked, whether part of the water evolved in None of the
, . , ^ , , 1 1 1- ^i I water from the

these processes might not have been produced trorn tlie "O- boracic acid.

racic acid, or formed in consequence of its agency ; but the

following experiments show, that this can not be the case in

any sensible degree.

I heated 8 grains of potassium, with about 50 grains of Proofs.
boracic acid, to redness in a tube of platina, connected with
a glass tube, kept very cool ; but I found that no moisture
whatever was separated in the process. I mixed a few*
grains of potassium with red oxide of mercury, and ignited
the mixture in contact with boracic acid, but no elastic pro-
duct, except mercury, was evolved.

J made some potash by the combustion of potassium in a
glass tube, and ignition of the peroxide ; I added to it dry
boracic acid, and heated the mixture to redness. Subborate
of potash was formed, and there was not the slightest indi-
cations of the presence of moisture*.

It

♦ These processes must not however be considered as showing, that Boracic acid

boracic acid that has been heated to whiteness is entirely free from "^^.^^ ^

, , . , . «, , whiteness not

w^aterj they merely prove, that such an acid gives ott no water by jy^g from wa-

combiuation with pure potash at a red heat. I have found, that bo- t«r.
racic acid in perfect fusion, and that has been long exposed to the
bla.'t of a forge, and that has long ceased to effervesce, gives globules
of hidrogen, when dry iron filings are made to act upon it. I added
to 54 grains of boracic acid in complete fusion, in a crucible of pla-
tina, 75 grains of flint glass that had been previously heated to white-
ness, and immediately reduced into powder in a hot iron mortar; by
raising the heat so as to produce combination, a copious effervescence
was produced ; and after intense ignition for half an hour, the^^xtqr^
vas found to have lost three grains and a quarter.

The combinations of boracic acid with potash and soda, that have
been heated to redness, I find lose weight when their temperature i^
raised to a much higher degree. Thus, in an experiment made in the
laboratory of my friend John George Children, Jlsq., and in which
Mr. Children was so kind as to cooperate, 71 grains of hydrat of
potash, mixed with 96 of boracic acid that had been heated as
strongly as possible in a blast furnace, lost by fusion together in a red
Jneat 11 grains, but on raising the temperature to whiteness the loss
increased to above 13 grains. 55 5 grains of hydrat of soda, mixed
vrith 80 of boracic acid, examined at intervals in a process of thit
)riud, continued to lose weight for half an hour, during which time ,
they were frequently heated to whiteness ; at the end of this period
tUe w^ale lost was 14 grains, of which at least one grain and a half

may

120 eOMBIKATIONS OF OXIMURIATlC GA8 AND OXIGEN.

The common It is evident from this chain of facts, that common potash

i ^^ ' and soda are hydrate, and the bodies formed by the coin**

bustion oF the alkaline metals are, as I have always stated,

pure metallic oxides, (as far as our knowledge extends) free

from water*.

I shall

may be referred to tlie acid. 95 grains of soda, ignited to whiteness
in a platina crucible, with 140 of dry flint glass, lost 22-2 grains j 80
gtains of boracic glass were added to this mixture j a fresh efferves-
cence took place, and after intense ignition for a few minutes, there
was an additional loss of weight of four grains and a half. The energy
with which water adheres to certain bodies in other cases is t<hown by
the experiments of Mr. Berthollet, Ble/n. d^ArcueU^ torn, ii, page 47.
Indeed it is impossible to say, that a neutral compound, or a fixed
acid, is ever entirely free from water ; it is only the first proportion*
that are easily separated. If the proportions of water in common pot-
ash and soda were to be judged of from their loss of weight, in com-
bining with boracic acid, it would appear to be from 19 to 20 per cent
in the first, and from 23 to 25 in the second.
Potassium and * After the experiments detailed in my last two papers, it may per-
sodiumnothy- ]japs appear unnecessary, at least to those enlightened British che-
mical philosophers, who have closely followed the progress of science,
to offer any new evidences to prove, that potassium and sodium are
not hydrurets of potash and soda; particularly as Messrs. Gay-Lussac
and Thenard, the ingenious advocates of this notion, have acknow-
ledged, in the Moniteur to which I have before referred, that it '\& not
tenable j but on a subject so intimately connected with the most re-,
fined departments of chemical philosophy, and with so many new ob-
jects of research, aoditioual facts cannot be wholly devoid of use au^
application.

Mr. .J)alton, \n the second volume of the work which he entitles
** A Niw System of Chefriical Pfiiinsopkt/,*' of which he has had the
goodness to send me a copy, has, I find in his fii*Kt pages, adopted
the idea, that potash and soc'a are metallic oxides ; but in the latter
pages has considered them as simple bodies, and the metals formed
from them as compounds of potash and soda with hidrogen. He has
piven no facts in favour of this change in his opinion : his principal
arf^uDtent is founded upon the process in which I first obtained potas-
sium* Common potash is a hydrat : when oxigen is procured from this
by Voltaic electricity at one surface, and potassium at the other surfacej
Mr. Dalton, conceiving that this oxigen arises from the water, states,
that the hidrogen of the water must eombine with the potash to forn^
potassium. It is evident, that, adopting such a plan of reasoning, lead
jfcod copper might be proved to be hydrurets of their oxides; for Mheu
these metals are revived from their aqueous acid solutious, oxigen is pro-
duced at the positive surface, and no hidrogen at the nejjative surface.

COMBINATIONS OF OXIMURIATIC GAS AND" OXIGEK. jQf

I shall now resume the detail of the experiments that I Potassium

, , . ^. x' £• • ' 1.' burned in oxV»

have made, on the relative attractions ot oximuriatic gas

and

In my first experiments for producing potassium and sodium, I used In the produc*

a weak powtr: and in these instauces, procnring the metals in rery *'°" °* potas-

,, . . , , . , „. ,,,, - „ sium inquan-

nuall quantities only, I perceived mo effervescence. When from five ^- j^j^rogea

hundred to one thousand plates art used for producing potassium, evidentlr

there is a violent efftivescence, and a production of hidrogen, and evolved,

sometim* s of potassuretted hidrogen, connected with the formation of

the metal.

Potassium, broxight into contact with redhot hydrat of pot?ish, dis- ^g jt jg jj, other
engages abundance of hidrogen, and the whole is converted iuio diffi- experiments,
cultly fusible potash.

327 ti;rains of hydrat of potash, that had been ignited, were made
to act in a gunbarrel on 745 grains of iron turnings heated to white-
ness. Some hidrogen was lost, and some hydrat of potash remained
undecompounded, yet 225 cubical inches of inflammable gas were col-
lected, and 50 grains of potassium, and a large quantity of an alloy
of potjjiSsium and iron foiraed ; so that it is scarcely possible to doubt,
that all the hidrogen produced from the decomposed hydrat of potash
was liberated.

Mr. Dalton conceives, that- there is an analogy between potassium Observations
and sodium, and the compounds of hidrogen with sulphur, phospho- on some opi
rus, and arsenic ; bat 1 am at a loss to trace any similarity between nions of Mr.
sulphuretted hidrogen, which is a gaseous body, soluble in water, and
having acid properties, and a highly inflammable solid metal, which
produces alkali by combustion. Potassium might as well be compared
to carbonic acid. Mr. Dalton considers the volatility of potassium
and sodium as favouring the idea of their containing hidrogen; but
they are less volatile than antimony, arsenic, and tellurium, and much
Jess volatile than n^ercnry. He n^eutjons their low specific gravity as
a circumstance favourable to this idea. I haye on ^ former occasion
examined this argument, first brought forward by Mr. I^itter ; but it
may not be amiss to add, that, if potassium is a compound of hidre.
gen and potash, hydrat of potash must contain an equal quantity of
hidrogen, with the addition of a light gaseous element, oxigen, which
might be expected to diminish rather than to increase the specific
gravity of the compound. ]\Ir. Dalton states, p 488, that potassium
forms dry hydrat of potash, by decomposing nitrous gas and nitrous
oxide; this is not the case: and he does not refer to experiment. I
find by some very careful trials, that potassium attracts the oxigea
and some of the nitrogen from these bodies, and forms a fusible coro-
pvund which may be decomposed, giving off nitrogen and its excesw
of oxigen, by a red heat, and which becomes potash, and not i^ry |iy^
dr»t of potash. ; ; i ^

Measre^

122 COMBINATIONS OF OXIMURIATIC CAS AND OXIOEN.

and Qxigen for the metaU of the hxed alkalis. I burnt a
grahi of potassium in oxigeu gas, in a retort of green glass,
furnished with a stopcock, and heated the oxide formed to
redness, to convert it into potash : half a cubical inch of
znS ©xirauri- oxigen was absorbed. The retort was exhausted, and very
Aticgasa * pure oximuriatic gas admitted. The colour of the potash
instantly became white ; and by a gentle heat the whole wa»
MttariaU of converted into muriate of potash : a cubical inch and ^^ of
^ H th'^""^:'* oximoriatic gas were absorbed, and exactly half a cubical
pea gtirea out. inch of oxigen generated. The barometer during this ope-
ration was at 30*3, the thermometer at 62 Fahrenheit. I
made several experiments of the sam* kind, but this is^ the
only one on whi«;h I can place entire dependence. When I
attempted to use larger quantities of potassium, the retort
usually broke during the cooling of the glass, and it was
not possible to gain any accurate results in employing me-
tallic trays. The potassium was spread into a thin plate»
and of course was much oxidated before its admission into
the retort, which rendered the absorption of oxigen a little
less than it ought to have been. In the process it waa
Seated in vacuo before the combustion, to decompose the
water in the crust of potash ; for in cases when this pre*
caution was not taken, I found that hydrat of potash
sublimed, and lined the upper part of the retort, and
from this the oximuriatic gas separated water a& well a&
oxio'en.
W»t«r separat- The phenomenon of the separation of water from hydrat
•f potash by"^^ of pota&h by oximuriatic gas was happily exemplified in an
•oiimuriatic experiment in which I introduced oximuriatic gas to the per-
*^ oxide of potassium, formed in a large retort, and in which

the potassium had been covered with a considerable crust
of hydrat of potash. The upper part of the retort and its
neck contained a while sublimate of hydrat, which had
risen in combustion, and which was perfectly opaque. As
soon as the gas was admitted, it instantly became transpa-
tent from the evolution of water; and on heating the glass

Messrs. Gay-Lwssac and Tlienard have convinced themselves, that
»otassinm and sodium are not hydrurets of potash and soda, by a
:|p«thod similar to that which I adopted and published some months
before, namely, by producing neutral salts from thezo.

COMBINATIONS OF OXIMURTATIC QAS AND OXIGEN. ]^5

in contact with the sublimate, its opacity was restored, and
water driven off.

In various cases in which I heated dry potash, or mixtares
of potash and the peroxide, in oximnriatic gas, there was
no separation of moisture, except when the gas contained
aqueous vapour ; and the oxigen evolved in the process,
when the heat was strongly raised, exactly corresponded to
that absorbed by the potassiurrt.

When muriatic acicj gas was introduced to potash formed Derorapositiom
from the combustion of potassium, water was instantly of muriatic
formed, and oximuriate of potassium*. I have made uo potash '

accurate experiment on the proportions of muriatic acid gas
decomposed by potash, but I made a very minute investiga-
tion of the nature of the mutual decomposition of this sub-
stance and liydrat of potash.

Ten grains of hydrat of potash were heated to redness in and by hydrat
a tray of platina, which was carefully weighed; it was intro- ^'^ 1^^^^^'
duced into a retort which was exhausted of air, and the re-
tort was filled with muriatic acid gas. The hydrat of pot-
ash was heated by a spirit lamp; water instantly separated
in great abuodance, and muriate of potash formed. A
strong heat was applied till the process was completed,
when the tray was taken out and weighed ; it had gained
^rf grains, A minute quantity of liquid muriatic acid was
^dded to the muriate, to ensure a complete neutralization,
find the tray heated to redness: there was no additional in-
crease of weight.

In the few experiments which I have made on the action Action of 90-

of sodium and soda on oximuriatic gas, the phenomena ap- ^'""^ ^^^ ^^*
J • J 1 u ^ J- • 1 ^ L Q'^ oximuriatic

peared precisely analogous; but sodium, as might have gas.

been expected, absorbed nearly twice ^^s much oximuriatic

gas as potassium*

M'hen common salt, that has been ignited, is heated Muriate of

with potassium, there is an immediate decomposition, and "°^^ ^^^"™'
, . . , . 11, T • 1 . , posed by pot^

by giving the mixture a red heat, pure sodium is obtained ; assium.

and this process affords an easy mode, and the one I have

always lately adopted, for procuring that metal. No hi- ^'; »f **"* "

^rogen is disengaged in this operation, aiid two parts of

* L e. Muriate of potash.

pptassim^

134 COMBINATIONS OF OXIMURIATIC GAS AND OXIOEN.

potassium I find produce rather more than one of so-
dium.

Thccxpen. p^om the series of proportions that I have communicated

ments agreea* . ^ •

Uetocakula. '° ^"7 last paper, it is evident, that 1 grain of potassium

•*"»• ought to absorb 1*08 cubical inches of oximuriatic acid ; and

that the potash formed from one grain of potassium ought
to decompose about 2'l6 cubical inches of muriatic acid
gas; and these estimations agree very nearly with the result
of experiments.

The estimation of the composition of soda, as deduced
from the experiments in the last Bakerian lecture, is 25*4 of
oxigen to 74*6 of metal, and this would give the number re-
presenting the proportion in which sodium combines with
bodies 22*; from which it is evident, that a grain of sodium

ought

• Or^ if soda be considered as dentoxide, which seems probable from
the experiments detailed page 114, -44; and on this supposition, tli* salts
of soda must be conceived to contain double proportions of acid. On
cither datum the proportion of oxigen in water must be taken as 7*5,
and that of hidrogen as 1, though other numbers might be found as di-
visors or multiples of these, which woiild equally harmonise with the
genera! doctrine of definite proportions. In my last communication to
• the Society, 1 have quoted Mr. Dal ton as the original author of the hy-

pothesis, that water consists of t particle of oxigen, and 1 of hidrogen ;
but I ha^e since found, that this opinion is advanced in a work publisheH
In 1789, A comparative View of the Phlogistic and Antiphlogistic Them-
Hvnothes'sof "**> ^y William Higgins. In this elaborate and ingenious performance
Mr. Higgins. ^^ Higgins has developed many happy sketches of the manner in which
(on the corpuscular hypothesis) the particles or molecules of bodies may
be conceived to combine j and some of his Tiews, though formed at this
rarly period of investigation, appear to me to be more defensible, assum-
ing his data, than any which have been since advanced ; for instance, he
considered nitrous, gas as composed of two particles of oxigen, and one of
nitrogen. Mr. Higgins had likewise drawn the just conclusion respect-
ing the constitution of sulphuretted hidrogen, from its electrical decom-
position. A,s hidrogen is the substance which combines with other bodie*
in the smallest quantity, it is perhaps the most fi;ted to be represented by
unity ; and on this ideji the proportions in ammonia will be 3 of hidrogen
to I of nitrogen, and the number representing the smallest proportion in
Remarks on ^^ich nitrogen is known to combine will be 13-4. Mr. Dalton, New Sys-
some of Mr. tein of Chemical Philosophy, pages 323 and 436, has adopted 4*7 or 5*1, as
Daltoirs. the number representing the weight of the atom of nitrogen ; and has

quott'd my experiment, Researches, Chemical and Philosophical, as au-
thorising these numbers j but all the inquiries on nitric acid, nitrous gas,
• , . nitrous

COMBINATIONS OF OXIMURIATIC OAt AND OXfGEN. 1S^5

•ught to absorb nearly 2 cubical inches of oximariatic gas;
and that the«ame quantity, converted into soda, would de-
compose nearly four cubical inches of muriatic gas. Muri-
ate of soda ought on this idea to contain one proportion of
sodium, 22, and one of oximuriatic gas 32*9; and this esti-
mation is very near that which may be gained from Dr.
Marcet's analysis of this substance. Hydrat of potash ought
to consist of I proportion of potash, represented by 48, and ^

one of water, represented by 8*5. This gives its composition
as lo'l of water, and 84*9 of potash. Hydrat of soda ought,
according to theory, to contain 1 proportion of soda 29'$,
and 1 of water 8*5, which will give in 100 parts 22*4 of

nitrous oxde, and on the decomposition of nitrat of ammonia stated
in t hat work, conform much more nearly to the number 13'4.

According to Mr. Dalton, nitrate of ammonia contains one proportioiii
of acid and one of alkali, and nitrate of potash two proportions of acid
and one of alkali ; but it is easy to see, that the reverse must be the case- '
Nitrate of ammonia is known to be an acid salt ; and nitrate of potash a
neutral salt ; which harmonizes with the views abovestated. Mr. Daltoa
estimates the quantity of water in nitric acid ©f speciBc gravity 1'5.4, at
27*5 percent j and this, acccording to him, is a stronger acid than he ob-
tained by decomposing fused nitre by sulphuric acid, which contained
only 19 per cent of water j and one quantity of sulphuric acid, according
to him, will produce from nitre more than an equul weight of nitric acid,
and he supposes no water in nitre ; so that his conclusion as to the quan>
tity of water in liquid nitric acid on his own data must be incorrect, f
find water in fused nitre, by decomposing it by boracic acid.

1 shall enter no farther at present into an examination of the opinions,
results, and conclusions of my learned friend; 1 am however obliged to
dissent from most of them, and to protest against the interpretations that
he ha« been pleased to make of my experiments ; and I trust tojiis judg-
ment and candour for a correction of his vieirs.

It is impossible not to admire the ingenuity and talent, with which Mr. Hypothesis of
Dalton has arranged, combined, weighed, measured, and figured his definite pro-
atoms ; but it is not, I conceive, on any speculations upon the ultimate P*'''"°^*
particles of matter, that the true theory of definite proportions must ul-
imately rest. It hasa surer basis in the mutual decomposition of the neu-
tral salts, observed b) Richter and Guyton de Morveau, in the Jiutualde-
compositions of the compounds of hidrogen and nitrogen, of nitrogen and
oxigen, of water and the oximuriatic compounds, in the multiples of
oxigen in the nitrous compounds; and those of acids in saJts, bbserved
by Drs. Wollaston and Thomson ; and above all, in the decompositions
by the Voltaic apparatus, where oxigen and hidrogen, oxigen and in-
8*minable bodies, acids and alkalis, A.c. must separate in uniform ratio*.

water;

(

l^ COMBINATIONS 07 OXIMtJIlXATIC CAS AKD OXXGEIT.

water; and the experiineuts that I have detailed conform as
veil as can be expected with these conclusions.

The proportions of potash and soda indicated, in different
neutral combinations, by these estimations, will be found to
agree very nearly with those derived from the most accurate
analyses, particularly those of Mr. Berthollet ; or the dif-
ferences are such as admit of an easy explanation.

Kyperoximu- I staled in my last communication the probability, that
^ * the oxigen in the hyperoximuriute of potash was intriple
Combination with the metal and oximuriatic gas; the new
facts respecting the peroxide confirm this idea. Potassium,
perfectly saturated with oxigey, would probably contain six
proportipns; for, according to Mr. Chenevix's analysis,
■which is confirmed by one made in the Laboratory of the
Royal Institution by Mr. E. Davy, hyperoximuriate of pot-
ash must consist of 40*5 potassium, 32*9 oximuriatic gas,
and 45 of oxigen.

I have mentioned, that-by strongly heating the peroxide
of potassium in oximuriatic acid, all the oxigen is expelled^
and a mere combination of oximuriatic gas and potassium
formed. I thought it possible, that at a low temperature a
combination might be effected, and I have reason to be-
lieve, that this is the case. I made a peroxide of potassium,
by heating potassium with about twice the quantity of nitre,
and admitted oximuriatic gas, which was absorbed: some
oxigen was expelled on the fusion of the peroxide, but a
salt remained, which gave oximuriatic gas, as well as muri-
atic acid, by the, action of suTphuric acid.

Its formaiion It seems evident, that in the formation of the hyperoxi-

^* '"* * muriate of potash one quantity of potash is decomposed by
the attraction of oximuriatic ^as to form muriate of potash;
but the oxigen, instead of being set free in the nascent
state, enters into combination with another portion of pot-

V ash, to form a peroxide, and with oximuriatic gas.

The proportions required for these changes may be easily
deduced from the data which have been stated in the" pre-
ceding pages. 5 proportions of potash, equal to 240 j^rains,
tnust be decomposed, to form with an equal number of
proportions of oximuriatic gas, equal to l64-'5 grains, 5 pro-
portions of muriate of potash equal to 367 grains; and 5 of

oxigen,

OFFSPRI)I0 OF All A86 AND ZEBRA. 1K7

oxigen, equal to 37*5 grains, combined with one of potasb,
equal to 48, must unite in triple union with one of oximu-
ri^tic gas equal to 32*9, to form one proportion, equal t»
n8*4 grains, of hyperoximuriate of potash.

(Tii he concluded in our next/

VL

Farther Account of a Mule Animal between the Male Ass
and Female Zebra. In a Letter from. Thomas Andaew
i^NiGHT, Fsq^s F.R.S., ^c.

To W. NICHOLSON, Esq.
Dear Sir,

J.N a former number of your Philosophical Journal* you ofFspiingofaBi
have given an account of a mule animal between the male assani zebrn,
ass and female zebra, which was bred by the present Eart
of Powis; and you have expressed a wish to obtain farther
information respecting it: I in consequence send you the
following particulars. .v/;toVj

You have justly stated, that the zebra would not admit Wild animali
the approach of the ass till his coat had been properly distinguish
painted to resemble her own; which circumstance is curi- ^^J^J^^^*"
ous, because it goes far to prove, that animals, in a state of
nature, distinguish and select those of their own species, in
part at least, by sight; while in a state of domestication, when
their colours become varied by the influence of cultivation,
they appear to be guided almost entirely by another sense.

The animal, which I proceed to describe, like other The anima!
mules, bore, externally, a greater resemblance to its male morereseia-
than to its female parent ; and until by near approach it* than the female
stripes, which were much less distinct than those of the ze- parsnt,
bra, became visible, it was not readily distinguishable from

• Received from the Right Hon, Sir Joseph Banks, Bart.,, P. R, S. ;
«nd inserted Vol 11, p. 267 of ihe quarto setiFi.

« wry

22g OFFSP&IllG OF AN ASS AND ZEBRA.

a very large and strong Spanish ass. T am ignorant whetlitfr
nature has given to the zebra, as to the ass, the power of
breathing through its mouth as well as through its nostrils;
or whether the passage of the breath is confined to the
nostrils only, as in the horse : but I observed, that the mule
zebra uttered its cry, which a good deal resembled the
braying of an ass, through its mouth ; corresponding in
thia respect with the male, which is obtained from the male
ass and the mare, and differing from that which is derived
from the horse and the female ass.
was intracta- The temper of the mule zebra, as might have been ex-
* pected from its parentage, was sullen, vindictive, and un-

tractable. It was nevertheless sufficiently subdued to per-
mit itself to be ridden ; but a considerable time generally
elapsed before the mule and the rider could agree about
the direction in which they were to move; and when that
point was in some degree settled, the labour, to the rider,
of impelling and guiding his companion, was found so
much to exceed that of walking on foot, that the services of
the mule were not much in repute, or often called for.
and a complete Attempts were made to obtain offspring from it both by
mule. ^j^g female ass, and the mare; but neither were successful.

It appeared to possess passions ; but, like other mules, to
Died fr»m an ^^ without powers. It met its death by an accident when
accident at four rising four years old, and consequently before it had ac-
jcafso . quired its full growth and strength: but its size and form,
at that age, indicated great powers of bearing weight and
undergoing fatigue ; and it would probably have been of
great value both as a beast of burden and draught, had not
its temper disqualified it for either oftice.

I am, dear Sir,

Your obedient servant,
THOMAS ANDREW KNIGH f.

Downton, 4pril the^6thi \81J»

Vlf.

'

ON POTASSIUM, 8«DIUM9 AND OXIMURIATIC ACID. 22^

VII.

Remarks on Potassium y Sodium, Sfc, ; in Reply to the Com*
municalions o/Jvstuh. By John Dalton*

To Mr. NICHOLSON^
SIR,

-ilN perusing the former of the two communicationg, pur-
porting to be a reply to the remarks on potassium and so-
dium in ray New System of Chemical Philosophy, (Journal,
vol. ^iS, p. 67) I felt interested in various acute observa-
tions of your correspondent; but at p. 72, where he inves- Quantity of
tii^ates the quantity of oxiwn in a eivcn volume of oximu- oxigen in oxi-
• *• • I T * . 1 ? • u u , J muriatic acid,

natic acid gas, I am quite at a loss to conceive now he had

obtaIn»ed so small a portion as 30*24 percent, when I had
found 50, (New System, p. 56O) calculating from the best
data I could procure, and which I was confident from my
own experience could Tiot be materially incorrect. Being
at that time particularly engaged, I could not attend to the
subject farther than to write a short note (Journal, p. I57J
requesting an explanation. This was given in the ensuing
number, (p. 219.) When I stated, that his data were de-
fectivey I did not mean erroneous ; no mathematician would
have understood me in that sense; I meant, that he had not
given sufficient data, and consequently that he had made
the problem an unlimited one. If I should propose the fol-
lowing question to your correspondent, namely, IJoxo long
7vouJd a body he in moving with a uniform velocity from the
Earth to the Moon, or through a space of 240,000 miles —
would he not find it necessary, that the velocity should be
given? Yet he has found means to answer a similar ques*
tion without the requisite data. The accuracy of the
answer then may well be suspected. It may be of service
toyourcorrespondent, and perhaps to others of your readers,
if I make out this charge more particularly. According to
Chenevix,
77*5 mur. acid + 22*5 oxigen zr lOOoximur. acid, by wt,

1*73

then, by measure 77*5 mur. acid X 22*5 oxi. =115:

1 '\i.5
measures;

Vol. XXIX.-.JUNE, 1811. ^ Thit

U4

Potassium
contains pot-
ash and hidro-
gen.

Heat separates
water and pot-
ash, ami eva-
porates them
at a certain de-
gree, whether
chemically
combined is
not known.

ON POTASSIUM, SODIUM, AND OXIMURIATIC ACI».

That is, 77*5 measures of muriatic acid -f- 34'5 measures
of oxigen, together 1 1 2 measu res, will , when chemically com-
bined, be 6qual to X measures of oximuriatic acid gas. How
your correspondent ascertains the value of a- in the above equa-
tion to be 100, 1 know not. It may as easily and as probably
be assumed 50 or 500. Surely he is not so ignorant of Mr.
Davy's experience as not to know, that 77*5 measures of
muriatic acid ga^ + 34*5 of oxigen, are far inferior in
weight to 100 measures of oximuriatic acid. The truth is,
the specific gravity of oximuriatic acid gas is a datum most
obviously necessary in the estimation of the oxigen a given
volume of it contains.

With regard to the facts and arguments respecting po-
tassium and sodium, I can bring forward the following,
namely, that fused hydrate of potash consists of potash and
water, or potash, hidrogen, and oxigen; that in the decom-
position of this article by Voltaic electricity, nothing but
oxigen gas is evolved, and potassium remains; hence I con-
clude, that potassium contains, and probably consists of
potash and hidrogen. If your correspondent is not satisfied
with these facts, and this reasoning, 1 cannot convince him.
The first fact I adopt from my own experience and that of
others, the second from that of Mr. Davy; and I am not
able to discover any flaw in the conclusive argument.

As to the question, what is the power that produces the
separation of water and potash ? I answer, heat. When I
say, that, by the application of heat to a certain degree,
** the alkali and water both evaporate," no one has autho-
rity from me to add "in a state of chemical union," nor
yet "in a separate state," thou gh only one of the two ways
is likely to be true. The fact was, I had not ascertained
when I wrote that, nor indeed have I yet, which of the two
is true. I am rather inclined to the latter; but as this is
one of a large class of chemical facts, T wish to have more
experience, and more time to reflect upon it, than at pre-
sent I possess. It forms an important inquiry according to
my views of chemistry, to ascertain the relation of water to
the acids,, alkalis, &c. in the very act of distillation ; name-
ly, whether the water in passing over is in a state of steam,
»uch as we find it in the atmosphere, or in a gasiform state

ft" : ... of

ON POTASSIUM, SODIUM, AND OXIMURIATIC AClD. l3l

of chemical union with the acid, &c. But, whichever be
the case, it is true, "that the process cannot be used to
expel the last portion of water from the alkali'% when the
object is to obtain a ponderable mass of alkali free from
water.

When fused potash is exposed to a red heat in an open Potash ex-
vessel, white fumes are observed to play over it; these, no f^^^^ open^*
doubt, are the particles or small drops of the condensed ve=!se!, and in
liquid hydrate, similar to the visible mist or condensed ^ S^n^arrc .
steam over hot water. From this and the above observa-
tion, then, it is probable, that in the gUn barrel experiment,
not only particles or atoms of hydrate of potash, but also of
potash, and of steam, may come into contact with the red-
hot iron; hence may be explained the production of hydru-
ret of potash or potassium, of oxide of iron, of hidro^en, Alloy of pot-
and of the wliite amalgam or alloy of potash and iron. This ash and iroa.
last is easily exhibited by keeping carbonate of potash in
fusion for some time in an iron spoon by an intense heat ;
after the potash is washed oif, the whole surface of the
spoon, which has been in contact with the fused carbonate,
is white as if tinned, and may be acted upon by an acid
without losing its colour*.

As for the complex nature of the decomposition of by- Complex na-

drate of potash, I see no «rreat reason to wonder at it. The *"'"® of the de*
' ^ -11 composition of

article consists of 3 elementary prmciples ; so does wood, hydrate of pot-
Why, it may with equal propriety be asked, does wood, in ^^^•
its decomposition by heat, exhibit such a mixture of
principles? Charcoal, water, carbonic acid, carbonic ox-
ide, cafburetted hidrogen, and hidrogen, are among the
products of the destructive distillation of wood.

I was surprised at your correspondent's observations on Levity of po-
the argument I have drawn for potassium being a compound tassium.
of hidrogen from its levity. I venture to say, that Mr.
Davy will allow the argument to have some force. In the
place referred to, Mr. Davy does not say a word about the
notion, that hidrogen united to potash ought to make a com-
pound specifically lighter than potash. His answer, which
is pertinent and to the purpose, is to those who object to
potassium and sodium being classed amongst the metals^

• • On pola^satcd iron see also Journnl, Vol, XXV, p. 51.

K 2 Bierely

IS^* ^.^ POTASSIUM, SODIUM, AND OXIMURIATIC ACID.

merely on account of their levity, 1 feel no repugnance t»

call those new bodies metals, be they hydrurets or not ; but

1 should be far from inferring, that the other metals are

also hydrurets. With respect to the resemblances between

the new metals and sulphuretted bidrogen, &c., they cer-,

tainly oxq many and striking; so are their resemblances to

the metals ; I do not undertake to decide which are most

Simple bodies numerous, I apprehend a piece of brass or other alloy bat

and com- gg many properties resemblins: the metal* as potassium atj^
pounds may i- < 11

haveresem- sodium; yet no one allows the former to be simple sub-

blances stances. This argument is at least sufficient to show, that

enough to be , , °

classed toge- simple and compound bodies may have so many points of

^'' resemblance, as to be fairly arranged in the same class. I

do not consider the discovery of the new metals less valua-
ble and important for being compound rather than simple
bodies; and though there may be several facts and experi-
ments, which seem to point tliem out as simple subj^tances,
yet till the preceding facts are controverted, the othej's
can do little more than excite doubts on the subject.
Combustion of Your correspondent, adverting to the combustion of po-
potassium ia tassium in muriatic acicl, argues, that the bidrogen is de-

muriauc acid ^ived from the acid, and not from the potassium ; and as a

no proof, that , . '^ ' .

it does not support of the opinion adduces Mr. Davy's experiments, in

contain hidro- which a mixture of equal parts of oxi muriatic acid and
bidrogen is by the electric srk converted into muriatic
acid. Granting the truth of the last deduction, the argu-
ment amounts to this, that, if two bodies, one of which is
known to contain bidrogen, by their mutual action devc-
lope that gas, it follows, that the other may not contain bi-
drogen. But the principal aim of introducing this sub-
ject into the discussion on potassium and sodium seems to
have been, to defend the notion of oximuriatic acid being a
simple substance, and muriatic acid a compound of it and
bidrogen. It is to this object that his calculation is di-
rected, on which I have animadverted at the commence-
"Thenatureof ment of this letter. The experiments alluded \o on oxi-
aci'dm)t yetas- ^^^^^^'^^ ^^^^ '^"^ bidrogen I consider of the most difficult
ccrtained. execution, and if Mr. Davy has succeeded in obtaining to-
lerable approximations to accuracy in his first trials, great
merit is undoubtedly his; still we want a more accurate

and

ON POTASSIUM, SOBItJM, AND OXIMURIATIC ACID-

133

und trust-worthy table of the speciiic gravity of muriatic
and oximuriatic arid gasses before the value of the experi-
ment can be duly appreciated; and it should be farther
ascertained wlmt proportionate condensation of volume is
produccv5 upon muriatic acid gas by admittin*^ to it ,\ of
its weiglit of water. It is curious to observe, that your cor-
respondent was fully persuaded, and proi. ably continues to
be, ofthe** incontrovertible argument 'the above experiments
afford to Mr. Davy*s opinions in regard to oximuriatic acid,
though he did not know at the time he wrote, whether the
•pecific gravity of muriatic acid was 1*4, or 1*9, but took it
at V7 ; and he now adopts I '258; and of the specific gra-
vity of oximuriatic acid he makes no mention whatever;
neither ofthe condensation or contraction of volume which
a very small portion of water produces on muriatic acid
gas; yet it is impossible to ascertain the bearing of the ex-
periments, till these three data are all of them pretty accu-
rately investigated. If your correspondent wish to institute
his calculus anew, I shall give him all the information I can
respecting oximuriatic acid: its specific gravity by my own
experience is 2*34; by Mr. Davy's, 2*45; by Thenard and
Gay-Lussac*s, 2*47; and by Dr. Thomson's, (in a letter to
me) 2'71. If the last estimate should be true, he will find,
that, adopting Mr. Davy's notions and estimate of muriatic
acid, there should arise nearly '-2^ measures of muriatic acid
gas from a mixture of 1 of oximuriatic acid and 1 of liidrogen.

There is one opinion on which we all concur; that it is Specific gra-

verv desirable the specific gravities ofthe various gasses '^"y "^ 5»sses

, -^ , , , .;.,."• -. . ,, ^ . •till a desidera-

should be ascertamed withm narrower limits, r rom what is turn of im-

stated above, it appears, we have a range from 1*3 to pg portance.
for muriatic, and from 2*3 to 2*7 for oximuriatic acid. v

Would it not be a proper object for the Royal Society to
depute a committee of its members to undertake the inves-
tigation? As long as it is left to individuals, each one "^ g
finds a result differing from that of another; and one autho- ^

rity is deemed as good as another ; so that it will, if no such
step is taken, be a long time before a general agreement
respecting these points is likely to be obtained.

Manchester, 1 remain. Yours,

Matfihe nth, 181U JOHN DALTON.

VIII.

KAIN TABLi:.

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METEOROLqGICAL TABLE.

t^

M ETEOROLOG ICAL TA I5LE,

By Dr. Clarke, of Nottingham.

1810.

Therniom.

Barometer.

Weather.

Winds.

MONTH.

January..
February
March . .
April ....
May ....
June ,. . .
July ....
August . .
September
October. .
November
December

5

5 2

3 3

s

g

>£

a

B

c

2s

c

-a

C3 2

u ■"

ffi,

(e^

rr,

o

5.3

18

36

10

54

14

3/

16

59

.30

43

10

70

32

47

9

68

29

47

15

78

38

57

10

77

42

57

J 5

80

40

57

10

S2

39

56

11

68

24

45

8

53

26

38

10

50

19

36

10

30-36I2975
30-34i2873

30-10
30-18
30-33
30-35
29'95
30-43
30-38
30-30
30-12
30-50

28-88
29-27
2905
2972
2940
29-39
2971
2903
28-86
28-85

s *-

1^

.a 2

J in

*

H

^^.

•^

-vi

c/5

ss

s

93

rt c

u

V

■ a

rt

U4

!?

^'

w

c«

30-05

2975
2962
2976
29-86
30-38
29-75
2979

30-10
29-86
29-44

29-62

0-29
0-68
0-41

0 33

1 05
0 35
0-31
0-52
0-31
0-54
0-55
071

2b

5

5

9

17

19

9

7

4

21

19

12

17

9

14

24

6

14

7

IS

23

8

26

4

7

28

2

16

7

15

12

19

9-

4

12

21

*10

1

6

IS

3«

5

>7

6

10

23

8

15

11

8

25

5

11

10

8

2i-:

I m

■ ■'X

3

9

ANNUAL RESULTS AT NOTTINGHAM.

Thermometer.

Wind.

Highest Observation, Sept. Qd, 82'' E. .
Lowest Observation, Feb. 20th, 14®N^.
Greatest Variation in 24 hours,

February 19-20 16''

Annual Mean 46**

Weather.
Fair..,
Wet...

Days.
.269
. 96

365

I • fnt^fr.

Winds, Timts.
N. &NE....143
E. & SE. . ... 79
S. &SW..,.,..157

W. &NW,...'. 8^

467

Barometer. Wind.

Highest Observ. Dec. a<st, 3050 NE.
Lowest Observ. Feb. igtl^ 28-73 SW.
Greatest Variation in 94

hours, May 2f)th io5

1 Annual Mean , , 29*83

Rain.^^^ ,, . Inches.
Greatest Quantity m July .... 385
Smallest ditto in September .. 0-62
Total Quantity for the Year.. 23-15

^ -mo i:t,-i

The Barometer is fti-mly fixed to a standard wall, on^ «m eWttiou ©f 130 feet; and
the Phiviameter is placed io a garden, 140 feet, (ram (He lew?! oi the /if^p |,.^;f{.

■■.„, ,,. -. .., , . .1 .1... > :.«.-. rH — < '■ XtJxL^iiOS t

tf*<^r(| Bash 94:

o«

156 OV IRO» "WATtK'PJfTS.

IX,

On the Use of Iron Pipes for conveying Water, and Made
of securing their Joints. In a Letter from Mr, Jojfph T.
Price.

To W. NICHOLSON, Esq, -^

Esteemed Friend,

F the enclosed facts should appear to thee likely to be
of any service to those, who may want a supply of water
conveyed from any distant source, thou art \velcome to give
them to the public in thy Journal.
I am,

Xhipe very sincerely,

Neath Abbey, J. T. PRICE.

lAFeb, 1811.

Wat«r-pipe #f ]Vfr. H. B, Way, of Bridport, had occasion, jn 1805, to
* lay down between eight and nine hundred feet of ii'on f>ipe,

in lengths about 6 feet each, and 3 inches in the bore. At
every 50 feet was a joint with flanches and screws ; the
other pieces were put together spigot and faucet fashion.
To make these tight, he wrapped round the spi<;ot end
8ome caoyas well saturated with white lead mixed with oil
to a propel' consistePfCe, and drove it into the faucet etK^ as
Kakingat the]] tight as possible. When a length of 120 feet was laid down,
jpjints, ^^ gj^^ ^,j^g plu*rged up to try the joints ; and it was found,

that two thirds of them leaked considerably. Being in-
formed by a neighbouring mason, that a linen manufacturer
had completely stopped the leaks in his bleaching cisterns,
jn which lie both cold and boiling was used, by means of
secured with % Parker and W} att's Roman cement, he procured some of
luting of Ro- thjg^ and luted every joint with it. In 12 or 14 hours the
■^ pipe vas tried, and found to be perfectly water-tight at the
which also joints ; but one of the pipes had a crack in it, which leaked,
stopped a cracjc ^^^^ ^.jjjg ^^^ ^g eifectually stopped by the cement,
and jn a leaden fhe lead pipe, used in the house, had also a leak in it,
?^^«- which

OV TROy WATER-.NTES. ] 3^

wliicli was stopped in a very short space of time by the ce-
ment. : . 1*

This work was done between the 10th and 24th of De-
cember, in very frosty weather; and the pipe was covered
Vith earth before the entl of t}>at month. It is about two
or three feet beneath the surface, in a loose, sandy soil; and
xvas kept constantly full of water, without any appearance
o^ leaking.

The water was so much discoloured by the iron for a The water »t
week or two, and on standing deposited so much scdi'meht, ^^^' discolour-
that it could not be used. To remedy this the same mason but this reme-
r^^commenrled to put some unslacked lime into the u p- " ■ ^^^ ^*®^'
per reservoir, or head of water, and open all the cocks be-
low to give it a quick run ; which he said would leave a
coat of- lime round the inside of the pipe, so as to prevent
the rust from coming off. This wasi done, and for a few
days after the water tasted very much of the lime; but the
taste soon went off, and the water, which is very soft, was
as gdod after it had passed through the pipe as at its
source.

In the following autumn the same gentleman soperin- Another water

tended the laying down of 36o feet of similar iron pipe, with.''^^'^^"'^ ^, ^
- ^ . nearly constant

a fall between 20 and 30 feet, the joints of which were se-. stream soon
cured in the same way. The supply of water here was. s,o ^^^^"^^ itself,
copious, that it was obliged to be kept running all night
and great part of the day. This soon cleared the pipe from,-
rust, so that after a few days the water came tlirough colour-
less, and consequently no lime was used.

In the summer of 1808, or 1809, two more pipes were Two more iaid
laid down in the neighbourhood in a similar manner, ex- ^^^'^•
tending together between tw© and three thousand feet; and
with equal success.

These were all perfectly sound and secure in the month pC All contUmc
February last ; a little before which Mr. Way, having occa- ^ound.
sion to put a new leaden pipe in his yard from the iron one,
found the latter, as far as it was examined, apparently as
good as when laid down, and the cement as perfect, only
&£emin;; harder.

]0t ECONOMICAL PROCESS JOR EVAPORATIOK.

X.

On the Invention of the Economical Process Jbr Evaporation
ascribed to Montoolfier. In a Letter from Mr. St.
Amand.

To W. NICHOLSON, Esq.
SIR,

Economica! Jl HE supplement to the XXVIUth vol. of your interest*
processor era- ing ^nd excellent Journal of Natural Philosophy, &c.,
porationsaWto . ° ,,• , , . ^ i -i

behivented by ju^^ published, contains an account of a process, abridged

Montgoiaer. from vol. LXXVI of the Aunales de Chimie published at
Paris in Noveuiber last. This process for procuring and
accelerating the evaporation of fluids , without employing
heat produced by the ignition of combustible substances y is
•aid to have been communicated in conversation by Mr.
de Montgolfier, This declaration of Messrs. Desormes
and Clement, authors of the article in the Ann. de Chim.,
is not translated in your Journal, which givea only aa
abridgment of it: but you may easily turn to it, and I beg
you will have th« goodness to satisfy yourself of the fact.
I am neither jealous nor envious of the fame of a«y one; on
the contrary 1 deem myself happy in having fallen on the
same idea and the same means with a man' of deserved ce-

But Mr. St. Ifbrity : but truth and justice give me a right to claim at

Amandhas a \^q^i a priority of date in the invention, and to this I shall
pnor clatni* r ^

confine myself. The following are incontestal»le proofs

of it.

fwrofSofthis, After the disastrous and bloody catastrophe of the lOtb
<if August, 1792, 1 took refuge in England, wbither I
brought with me the same process, which 1 employed my-
self in developing and varying in several ways ; giving it a
greater extent, and applications more numerous, than those
]rnentior>ed in the Ann. de Chim., or in your Journal, Thes*
developements were proposed and submitted to the British
govermnent about fifteen years ago. They were known»
iippicved^ and patronized by several persojis, distinguished

fo?

ECONOllilCA'L PRfeciSS FOR EVAPORATION. 15^

for their rank, knowledge, and situations; by ministers,
peers, members of parliament, &c. Several learned socie-
ties, artists, and government contractors, whom the minis-
ter was desirous of exciting to carry it into execution, were
acquainted with it. It is now nine years since the raanu- Papers stolea
scripts, which contained a full account of the invention, ^^J^^^^*^^®"**
with various other matters, and which were in the hands
and under the care of ^pyeroroent, were taken away by
some treachery, respecting which there ave only conjec-
tures.

About that time, s.r, I had the honour to request you to Farther proof*,
assist me with your knowledge and distinguished talents, io
rendering them into the English language, with which I
have but an imperfect acquaintance; and to show you au-
thentic certificates of the experiments, that I had made
several years before with an apparatus, to which I gave the
lUrni^ of a pofi/chrest machiney on account of the variety anrf Polychrest raa-
muitiplicity of its applications. I appeal lo your candour *^^"^®*
and impartiality, to confirm the proposal I had the honour
to m^ike you on this subject, ai[»d the production of the* cer^ Vtnalfawd.-' ♦
tificates, which ar^ still in my possession, if you still re-
member the clrcuuistaiice ; which indeed was the occasion
of my first bavins^ the honour of beinor known to you.

The apparatus 1 have mentioned, for which 1 obtained Caveats at the
several caveats in the patent office more than twelve years P'^'*^"^ otiice.
ago, was ordered by the nobleman who was then first Lord
of the Admiralty, whose kindness and encouragement have
supported me, and whose protection I have still the honour
to enjoy. His zeal for the good of the public, and for the
sciences, induced him to cause the apparartus to be con- An apparaftJi"
strueted at his own expense, under my direction^ as appears constructed
by the certificate of the experiuients made in his presence, {^ 1798.
feigned by himself some time after, and dated in 1798,
which 1 have in my possession. After such authentic offi-
cial testimonies, I presume 1 need not appeal to several
others, which, though highly respectable in themselves,
would add nothing to the validity of the proofs already ad-
duced. All these person*^, of whom 1 could give you a list,
are still living; and as most of them are known to you, they
would confirm, if requisite, the publicity, which 1 beg the

140 COMBUSTION OF ETHER AND METALS IN OXlMURIArxC GAS.

favour of you to give this letter in the next number of your
Journal.

■: I have the honour to be, -mstd A'^"

With a just and high admiration of your tftlents.

Your very humble and very obedient servant,

ST. AMAND.

iViD. 25, York Building St New Road,
*'\ May the I5th, 1811.

XI.

On the Combustion of Ether, and of Metals, in Oximuriatic
Gas: by Mr. Yajx Meerten, anc? a>fr. Strati ngh*.

Combustion of ^/^S a proof of " the property of sulphuric ether to burn
stances in oxi- ^^^^ flame in oximuriatic acid gas, leaving a little oxide of car-
muriatic gas. bon,Mr. Van Meerten points out the following experiment.
Ethicr. Let a piece of the whitest possible sulphate of lime re-

xnain some time in ether. Set fire to this piece well soaked
in ether, and introduce it under ajar filled with oximuriatic
gas : the ether, or rather its hidrogen, will burn rapidly, and
the surface of the gypsum will be covered with a coat of ox-
ide of carbon.
Bm)^. The combustion of brasb and of tin is etfected in this gas

as easily as that of iron in oxigen. Take a slender brass
wire, twisted into a spiral, and termini^ted by a piece of
kindled charcoal ; immerse it in ;* jar of oximuriatic gas ;
and it will burn rapidly and entirely, throwing out sparks.
At the same time it may be seen, that the charcoal has not
the property of burning in it, for it remains unaltered. A
X^tu tin wire exhibited the same phenomena.

• Ann. de Chimie, vol. LXXIII, p. 87. Translated from Tromn^s*
dorff's Journal der Pharmacie, by Mr. Vogel.

A copper

COMBUSTION OF ETHER AND MBTALS IN OXIMURIATIC OAf. 24 J

A copper wire does not burn in this gas, but becomes as Copper,
soft as lead.

A brass wire not heated redhot does the same. Brass.

This gas has no action on lead-wire. Lead.

A wire of red French gold melted, without throwing out Gold,
sparks.'

Pure silver wire, and iron wire, were not altered in it. Silrer.

Mr. Stratingh, in verifying the preceding experiments, Brass,
prefers making the extremity of the brass wire red hot, to
adding a burning coal to it. He could not succeed in burn-
ing tin wire. . Tin,

Pie effected tlie combustion of a very slender copper Copper,
wire, the extremity of which was pointed and red ^hot.
The inside of the jar was covered with green oxide. of
copper.

A wire of ducat gold did not grow red, or melt, in the Gold,
gas, but was slightly oxided. This difference probably
arose from Mr. Van Meerten's French gold containing
more copper.

Very slender silver wire melted, aftet its extremity had SiWer.
been made red hot.

Iron wire by itself was not altered : but on adding to its Iron,
extremity a wire composed of an alloy of three parts of
antimony with one of tin, which was heated a little before
its immersion, the iron wire gave out much red vapour, and
the inside of the jar was covered with a beautiful red oxide
of iron.

Camphor alone does not burn in this gas: but if a piece Ca^p^jg^,
be stuck in the end of a cleft stick, wrapped round with
tin foil, and this powdered with metallic antimony, the
camphor will begin to burn with a deep red flame.

Oil of turpentine, or of cloves, poured into this gas, gives Essential oi!i,
out some fumes, but very little light*.

♦ A raj vretted witU oil of turpentine takes fiie in oximunatic gas.
Vogel,

XIK

I0t ILLVSTHATfOK OF MK. «6WAIlt)'« tMtOHV OV llAl^%

XII.

Observations in Itfustrailon of Mr. Howard's Theory of
Hairif In a Letter from TiloMAs FoiisxER, Bsq*

To W. NICHOLSON, Esq.

sm,

.S the following observations tnay serve farther to illus-
trate Mr. Howard's ingenious Th<.^ry of Rain, (see hispapef
on the modification of clouds,) I shall request your insertion
of them in your scientific Journal.
Appearance of Q^ the I6th inst. the day was close and warm, in the
I8ih afternoon I observed several different modifications of cloud

dispersed about in the atmosphere at different altitudes.
In some places cirro-stratus might be distinguished ; in
others, the clouds shewed a tendency to cirro-cumulative
aggregation, cumuli increased in density, and cirrot^e fibres
transversely crossed their summits, forming cumulo-straluSf
which like mountains transfixed by the mighty shafts of
giants appeared in the horizon, and represented a majestic
appearance ; while in other places the process of ninihifi-
cation appeared going on rapidly, and distant thunder was
heard. About six o'clock the sky, seen between the clouds
» under the descending sun, appeared of a very unusual brown-

ish lake colour. As the evening advanced the mountainous
clouds in the horizon appeared of a deep blackish blue
colour, their edges as well as those of other detached clouds
above thera exhibiting a bright golden colour. Flocks of
cumulus floated along in the wind, and refracted dark lake
coloured light; by degrees all the clouds lost their distinc-
tive characters as separate r;;odifications, and became one
dense mass, which ended in rain during the night.
19tb^ Qn the. 19th it rained all the morning, but held up in the

evening; the continuous sheet of cloud however remained,
notwithstanding a strong wind from the north.
andSOthof Early on the morning of the 20th the same uniform sheet

*'* of cloud obscured the sky. As the day advanced it broke,

and this dense sheet of nimbus, which had been origi-
nally formed by the collapse of several distinct modifi-
cation*

ATOMIC PHI NCI PLEB OF CHEMISTRY. l^$

cations, appeared to resolve , itself into them Bgain ; as <he
sheet broke part of it seemed to mount up into a higher
and comparatively calm region, and formed itself into cirro"
cumuluSi in some places disposed like windrows of hay, in
others consisting: of small roundish nubeculse of various
sizes; and into cirro-stratus, consisting either of flat sheets
of thin vapour with dentated edges, or disposed in streaks:
other parts of the once continuous sheet of nimbus descended
into a lower region, and floated along in flocks of cumulus,
with a strong wind, and the day became very fine. In the
evening the distinct modifications again seemed lost in a
general mistiness of the atmosphere, which as it became
darker seemed very red coloured, and this vapour was seen
to thicken in particular places which became dense nitnbi
again, and gave forth vivid flashes of lightning, and thunder
storms continued through the night.

From the evident decrease in the quantity of cloud dur«
ing the fine part of the day, it is evident, that, while part of
the sheet of nimbus, which obscured the sky in the morning,
divided itself again into the several modifications, the col-
lision of which originally formed it; great part must have
been absorbed by the air* : this is farther probable from the
great transparency and dense blue colour of the sky between
the clouds.

The insertion of these observations in your next number
will, if convenient, oblige your constant reader,

Clapton, Hackney, THOMAS FORSTER.

May 21, 1811.

XI n.

Observations on Dr, Bostock*s Review of the Atomic
Principles of Chemistry, ify John Dalton,

To Mr. NICHOLSON.
SIR,

il. Bostock's dissertation on the atomic system of o^e- d^ g ,-t^^j^,5
mistry in your Journal (Vol. XX VIII, page 280) may be remarks on ihe

* See Mr. Van Mons's paper iu your Journal for September, 1809 j
Also Rees*i Cyclopedia, article Cloud.

divided

I

144 ATOMIC PRINCIPLES Ot CHEMISTRY.

atomic system divided into two parts; one of which relates principally to
the theory of cliemical combinations, which 1 have embraced
from an extensive comparison of facts and observations fur»
nibbed by the writings of others, and from a careful and
laborious train of ex})eninental investigation of my own ; the
other relates to liis application of the theory to the solution
of a few of the more simple and common combinations. On
the former of these parts I beg leave to make a few observa-
tions r on the latter 1 think it is altogether unnecessary to
say any thing, unless it be to correct a iijisrepresentation
or two whi<?h Dr. Bostock has accidentally introduced,
namely, that oxigen and hidrogen in water are as 85*7 to
14'3 in weight, and that these numbers are as 7 to 1 nearly
(page 285) ; and that 1 conceive nitrous oxide to be a binary
compound (page 290). The weights of oxigen and hi-
drogen in water are stated (vid. New Syst. p. 275) to be
fe7*4 and 12*6 respectively ; and it is nitrous gas which I
maintain to be binary^ and nitrous oxide and nitric acid to
be ternary compounds.
Meaning of I do not exactly agree with Dr. Bostock as to his remarks

th« terms, ^^^ ^^^ difference between theory and hypothesis] these
Boihesis. terms as far as I can learn from their common use differ

only in degree. Theory is all or the greatest part of the
facts reduced to regular laws; hypothesis is where only a
few facts are reduced to laws, and the rest are either irre-
ducible, or are yet only in a train, or have their accuracy
Jiuspected, I think no one would seriously advance "any
hypothfcciis on any subject, that hud not some one or
oaore facts previously established in its favour. What is
theory to one man may be hypothesis to another. If
Newton had lived in an age when no malheinatician bnt
himself existed, he might have established his beantil'ul
theory of gravitation to his own satisfaction ; but it must
have been only an hypothesis to the rest of his contempo-
raries. These observations lead me to remark farther,
•that my chemical doctrine on combination is not, ** alto-
gether hypothetical," according to Dr. Bostock*s own
definition. I remember the strong impression which at a
very early period of th«'se inquiries was made b}'^ observing
the proportion of^xigen to a^ote, as 1,2 and 3, in nitrous

oxide.

\
▲TOMtC PRINCIPLEg OF CHEMISTRY. l4^

nJxidei nitrous gas, and nitric acid, according to the ex-
periments of Davy. And Dr. B. must confess, that the
greater part of the facts I have stated in my book, as the
g-rounds from which 1 draw my conclusions, are not new;
but facts that have been investigated by others before me,
and often with the same results;

Dr. Bostock must be aware, that in writing my System^
of Chemistry^ I have presumed all along, that the future
readers of it would be tolerably acquainted with the various
branches of the mechanical philosophy; otherwise I must
have made a cyclopedia of it; one department must have
treated of statics, another of dynamics, another of hydrody-
namics, another of pneumatics, &c. This was not my
design. If therefore I have announced certain rules as
proper to be laid down, and have given no demonstration
of them, it was because they were deemed obvious to the
class of 4"eaders I expected, or otherwise were such as could
not be demonstrated but by the gradual developement of
the system itself in its progres'*.

I proceed now to point out the mechanical consistency Mechanical
of the Ist rule, which Dr. Bostock has quoted, page 283, consistency of
,.,.,,, I u- *• r^ t r Mr. Dal ton's

namely, that "when only one combination of two bodies ^^st rule of
can be obtained, it must be presumed to be a binary one, combinatioa.
unless some cause appear to the contrary" ; and if this be
established, the other three which he quotes may be consi-
dered as corollaries from it.

Let us suppose a mixture, for instance, of hidrogenous Instance in tli«
and oxigenous gas, in such sort, that there are the same 0?^^^^"'^
number of atoms of each gas; now as the gasses are uni-
formly diffused, each atom of hidrogea must have one of
oxigea more immediately in its vicinity. The atoms of
hidrogen are all repulsive of each other; so are those of ox-
igen : the atoms of hidrogen are all equally attractive of
those of oxigen, and the attraction increases in some un-
known ratio as the distance diminishes. Heat, or some
other power prevents the union of the two elements, till by
an electric spark, or some other stimulus, the equilibrium
is disturbed, when the power of affinity is enabled to over-
come the obstacles* to its efficiency, and a chemical union of
the elementary particles of hidrogen and oxigen ensues.

Vol. XXIX,— June, 1811. L Now

146 ATOMIC PRIiTCIPtBS OP CHEMISTRY.

Instance in the ipiow the question 18, whether, according to the received

composition , r • t

ef water. 'aws ot motion, each one atom ot oxigen should unite to the

one of hidrogen next to it, or whether 7 atoms of oxigen
should leap over all the more proximate atoms of hidrogen
to another at a greater distance, and consequently less at-
tractive, and that finally only -fth of the number of atoms
of hidrogen should be engaged by the oxigen and the rest
remain in a state of freedom as before. The former is the
conclusion I adopted, and thought it would scarcely require
any elucidation ; the latter is thought by Dr. Bostock equally
plausible as the former (page 291). However till it can be
shown, that a less force can overcome a greater, I must re-
fuse my assent. Besides there is another consideration, that
has no small weight with me; it is known, that the oxigen
carries the greater part of its heat, and in all probability of its
repulsion along with it in its combined state; it would
therefore be an odd phenomenon, if it could be rendered vi-
sible, to see 7 atoms of oxigen surrounding 1 of hidro-
gen of equal size, all the atoms of oxigen repelling one
another, but retained by an atom of hidrogen at the
centre, whilst a number of atoms of hidrogen are around,
allequally attractive of oxigen with the one engaged. But
the difficulty does not end here : though I am persuaded
the relative weights of the hidrogen and oxigen in water
are nearly as 1 to 7, 1 by no means assert, that they are ac-
curately so. Perhaps Dr. Bostock would prefer the ratio
of 15 to 85 ; that is, in the smallest integers, 3 to 17- Now
upon this view of the subject we must picture to ourselves
3 atoms of hidrogen surrounded by 17 of oxigen as con*
stituting 1 atom of water; the remaining 14 atoms of hi-
drogen must be conceived to continue in their elastic state
as spectators, and not to disturb the equilibrium of the
atom of water. This may be the constitution of an atom of
water; but it is wonderful, that in the decomposition of it
by galvanism, nothing but hidrogen and oxigen should be
produced, and never any new combination should arise out
of so complex a system of particles as an atom of water
exhibits to view. Would it not have been an improvement
to have formed a set of atoms on purpose for water, by
melting tJ of hidrogen into one, and 17 of oxigen into one?
^^feoth you and your readers will probably think by this

time^

AtOMIC PmNCIPLES OF CHEMISTRY. 14?

time, that I have proceeded far enough in the develope- « Vj

luent of the truth of a proposition almost self evident ; if
not t may resume it on some future occasion.

The 2d, 3d, and 4th rules are necessarily consequent to 2^, 3d, and
the 1st. When an element A has an affinity for another ' ^" ***
B, 1 see no mechanical reason why it should not take as
many atoms of B as are presented to it, and can possibly
come into contact with it (which may probably be 12 in
general), except so far as the repulsion of the atoms of Q
among themselves are more than a match for the attraction of
an atom of A. Now this repulsion begins with 2 atoms of
B to one of A, in which case the 2 atoms of B are dia-
metrically opposed; it increases with 3 atoms of B to 1 of
A, in which case the atoms of B are only 120° asunder;
with 4 atoms of B it is still greater as the distance is then
only 90"; and soon in proportion to the number of atoms*.
It is evident then from these positions, that, as far as powers
of attraction and repulsion are concerned, (and we know «f
no other in chemistry) binary compounds must first be
formed in the ordinary course of things, then ternary, and
so on, till the repulsion of the atoms of B (or A, whichever
happens to be on the surface of the other), refuse to admit
any more.

1 shall now proceed to the 5th, 6th and 7th, or remain- 6th, 6tb, and
ing rules, which Dr. Bostock has not quoted, but of which '^^^'■"'•^•
he is equally in want of an explanation, or he would not
have formed such conjectures as that" it seems the most na-
tural to regard the sulphuric acid as the binary compound
of sulphur and oxigen," and that carbonic acid is a binary
and carbonic oxide a ternary compound, and that nitric
acid is a binary compound of azote and oxigen and nitrous
gas a ternary, and that nitrous oxide is biliary, &c. (pao-e

• I find from the principles of statics, that, upon the supposition of
spherical atoms of eqnnl size, and that the law of repulsion after chemi-
cal union is the same r\s before, namely, reciprocally as the central dis-
tance, the repulsion of any one aiom ol B upon another of B, to separate
it from A, is a constant quantity, on whatever point of the surface of A
it may be placed ; so that when there are 3 atoms of B, the 3d atouji is
repelled twice as much b) the other two as it would be by a single atom -^

placed diametrically opposite. When there are 4 atoms, thea the 4th ii *
three limes as much repelled, Ac.

L « 887,

148 ATOMIC PRllfCIPIES OF CHEMISTRY.

5th, 6th, and 287> 290. The 5th rule is "that a binary compound
I rues. gliould always be specifically. heavier than the mere mix-
ture of its two ingredients,*' The principle on which this
. rule is founded is recognised by chemists as general, if not

universal; namely, that condiensation of volume is a neces-
sary consequence of the expulsion of heat by the exertion of
affinity. Thus, steam is specifically heavier than a mixture
of 2 parts hidrogen and 1 oxigen; ammoniacal gas is in like
manner heavier than 21 azote with 72 hidrogen. The 6th
rule is that **a ternary compound should be specifically hea-
vier than the mixture of a binary and a simple, which
would, if combined, constitute it ; and the 7th, that " the
above rules and observations equally apply when two bo-
dies, such as C and D, D and E, &c. are combined."
These rules are founded on the same principle as the f6r-
mer, which principle entirely precludes the notions of ni-
trous oxide and nitric acid being binary compounds, and
discountenances those of carbonic and sulphuric acid being
binary compounds.

After making these observations on the general rules,
I shall now advert to more particular objects. I have
already remarked, that explanations and elucidations similar
to the above were what I thought unnecessary to enter upon
in the work alluded to : it is not improbable but I may have
been mistaken in this respect, especially if such inquiries
and observations as the following should be frequent. ** When
•* bodies unite only in one proportion, whence do we learn
*«that the combination must be binary ? Why is it not as
*• probable, that water is formed of two atoms of oxigen
«* and one of hidrogen, of two atoms of hidrogen and one
** of oxigen, or in short of ani/ assignable number of atoms
•* of hidrogen and oxigen ? I do not perceive that Mr.
'* Dalton has given any reason in support of this binary
•* combination in preference to all the rest; and / am una*
'* hie to conjecture what reason can be urged in its favour,'^
(page 283]. Ihopesuch remarks will be no more adduced;
and farther, that if any one should inquire, for instance, why
1 part of carbone, which takes 1'28 of oxigen, or 2-56, does
not also occasionally take 3*84 and 5' 12 parts of oxigen,
it will be understood, that the reason I should assign is,

that

ATOMIC PRINCIPLES OF CHEMISTRY. 24^

that in the state of carbonic acid there are two atoms of oxi-
gen combined with one of carbon, and a third or fourth
atom of oxigen, however it may be attracted by the carbon,
cannot join it, without expelling one or more of the atoms
of oxigen already in conjunction. The attraction of the
carbon is able to restrain the mutual repulsion of two atoms
of oxigen, but not of rhrse or more.

The drift of Dr. Bostock*s remarks and objections, in
page 285, is quite beyond my comprehension. The single
object I had in view in writing the paragraphs there quoted
was, to find the relative weights of hidrogen and oxigen in
a pound or any other given weight of water, I hav^ de-
duced them as 1 to 7 ; whether right or wrong may be a
question: but certainly I had no other object in view, and
therefore T consider that as the only one to which any criti- ^
cism can properly apply.

• I must object to such ^.oose quotations as the following ; Looseness of
B«mely, that I have assumed, ** that when only one com- quotation.
bination of two elementary bodies can be obtained, it must
be binary ;" my language is, " it must be presumed lo be a.
binary one unless some cause appear to the contrary.^* Sup-
posing for instance, that my hypothesis had been formed
previously to the discovery of carbonic oxide, I must have
concluded, according to Dr. Bostock's quotation, that car- ^
bonic acid was a binary compound ; whereas 1 should have
compared carbonic acid with the other acids, and found
that like them it ought to contain at least two atoms of
oxigen to one of base, and this with me would have ap- '

peared " some cause to the contrary." Again, ** only one
combination of oxigen and hidrogen, and only one com-
bination of hidrogen and azote can exist," (page 284.)
Knowing that I never entertained such ideas, \ was curious
to find out those passages in my book, which could possibly
be so far misapjprehended, and I think they must have beeu
the following: " As only one compound of oxigen and hi-
drogen is certainly known," (page 275), and ** only one
compound of hidrogen and azote has y»»t been discovered,"
(page 415), These ideas however are repeatedly ascribed
t9 me, and ip the most express manlier. <* We have never

^Hl) ATOMK PRINCIPLES OP CHEMISTRY.

yet been able to produce more than omp combination with

each of these substances, therefore Mr. palton concludes,

that only one combiuatiou can possibly exist," (page 286,

»ee also note.)

Siz« of atoms Though I am fuHy persuaded wie are in possession of data

not dependent sufficient to decide upon the relative weiifkt of atoms, we

on their , i • • r»^i . •

veight. ^^^ "ot m regard to their size, 1 his last is a matter of mere

speculation. Dr. Bostock seems to think the size must be
in direct proportion to the weight, I should however rather
suppose, that atoms of dili'erent bodies may be made of
ijaatter of different densities, if the expression may be al»
lowed; thus mercury, the atom of which weighs almost
:>70 tinpies as much as that of hidrogen, I should conjecture
was larger, but by no means in the proportion of the
weights, which would require a diameter of live or six times
the magnitude. Perhaps in a question of this sort Newton
has a better claim to be heard than either of us; he says,
(1 think in the 31st query to his Optics) " God is able tq
create particles of matter of several sizes and Jigures, and
in several proportions to the space they occupy, and perhaps
of different densities and forces* • • • • ^at least I see nothing
of contradiction in all this."

• Knowing that Dr. Bostock had occasionally communi-
cated several chemical essays through your Journal, I was
purious to see whether he had not furnished me with some
arguments in behalf of that doctrine, which he thinks
** depends for its proof entirely upon subsequent observa-
tions and experiments." In the Xlth vol. of this Journal,
page 75, May 1805, he has given valuable analyses of the
acetate and superacetate of lead. The results give the pro-
' pprtions of lead and acid as under :

Superacetate— Lead 6*12 or 100

Acid 3 •• 49

Acetate — Lead 8'4- or 100

Acid 2 ••24

A number of such analyses as these would compel Dr.

/ Bostock, and others of your chemical readers, to examine

the theory of chemical combinations which 1 have offered to

them

•jCiENTIFIC NEW*. SMl

them with more altention, than 1 fear they do. The present
state of chemical science imperiously demands it,
I remain, yours &c.

Manchester, JOHN DALTON*

itfoy Mtf 15/A, 1811. i;i>p«rfif

SCIENTIFIC NEWS.

Royal Society of Edinburgh*

N the 4th of March, Mr. Allan read a paper on the Rocks in the

rocks of the environs of Edinburgh, being the first of a 1^7''?"^ ?f
1 . 1 . 1 1 • 1 • nil Edinburgh,

•cries, which he proposes to read on this subject. Ine

present embraced the rocks of St. Leonard's Hill and Salis-
bury Craig. The specimens illustrating the subject he pre-
sented to the Society, to be deposited in their cabinet.

On the 18th, Sir George Mackenzie read some geological
remarks on the appearance presented by different rocks in Ice-
land ; and showed their importance in connecting the pheno-
mena of volcanoes with the principles of the Huttonian theory. Huttoniaa
Sir George brought forward the results of Sir James Hall's ex- t^^^'^y*
periments on heat modified by compression, and successfully 3.«^K!(

applied them to support his conclusions. The facts were
explained in a satisfactory manner, and the whole paper
was so important in a geological point of view, that we re- »Hj ni ItpO
g ret that it is not in our power to give an analysis of it.**' 'S^'*
We understand, however, that it will form a part of ^^e ^^^.q^j^^ ^^
account of Iceland, which Sir George and his friendis are Iceland,
about to publish, the work is now in the press.

On the Ist of April, Dr. Brewster read a description of a CapiHaTVkt-^
new instrument, for measuring capillary attraction, the in- traction. ^^
Btrument to be exhibited at a future meeting.

Prof. Playfair read a very interesting paper, being pa>"t pj.^ggg^j. pi^^^
of his new edition of his illustrations of the Huttonian fair's il lustra-;
theory, entitled Jlemarks on the natural History of Volca- H[^utto,i[]iJJ ■*
^lOeSt theory,

Hoyal

list SCIENTIFIC NEWS.

Royal Medical Society of Edinburgh,

The Society will give a set of books, or a medal of five
guineas value, to the author of the the best experimental
e^jsay in answer to the followmg question.
Frut question. Does any decomposition of acids and alkalis take place
on their unitingto form neutral salts, according to an opinion
lately advanced by Mr. Davy in respect to muriates?

Honorary, extraordinary, and ordinary members of the
Society are alone invited as candidates, Tlie dissertations
are to be written in English, Latin, or French, and to be
delivered to the Secretary on or before the first Day of
December, 1812, And thp adjudication of the prize will
take place in the last week of February following, l^o
each dissertation is to be prefixed a motto; and this motto
is to be written on the outside of a sealed packet, containing
the name and address of the author. No dissertation wiU
be received with the author's name affixed ; and all disr
X fiertations, except the successful one, will be returned, if
desired, with the sealed packet unopened.

Wemerian Nfttnral History Society.

At the meetinir on the 6th of April, Mr. William Elford
Leach Jaid before this Society an arrangement of the na-

X>ipter«. • toral ?rib^ o? diptera, eproboscidea of Latreille, with de-
scriptions of the species, which he illustrated by drawings
and specimens. At the same meeting Prof. Jameson read

Coal in the ^" account of the occurrence of coal in the first sandstone

irst sandstone, formation in Thuringia and Silesia; whence he inferred
the possibility of coal existing in the extensive depositions
jof red sandstone in Scotland, in which that valuable mine-
ral has not hitherto bieen discovered.

SpAJety*sMe- The first volume of th.e Werneriap Society of Natural

jaoirs. H'stpry hi^s just been published.

India Man- The 2d part of the Maritime Directory for navigating

time Direc- ^^^ from, and between the Ports of India, China, &c., by

^ James Horsburgh, Esq., F. R. S. is in the press, and ip

expected to be ready for publication in July,

SCIEKTIFIC WEWS. 153

fUport of the Proceedings of the Mathematical and Physi-
cal Class of the French Institute^ continued from p, 79.
Mr. Yaiiqiielin has analysed tobacco, with a view to de-^^^jy^jgof
tect the principles, that cliaracterise this plant, and have tobacco,
occasioned it to be chosen for the uses for which it is eni^
ployed : and to ascertain the changes produced in it by the
preparations it undergoes for sale. It appears to contain an
animal matter of the albuminous kind, malate of lime with
excess of acid, acetic acid, nitrate and muriate of potash, a
red matter the nature of which is unknown, muriate of
ammonia, and finally an acrid and volatile principle appa- Peculiar prin*
rently different from any other known in the vegetable ciple in it
kingdom. It is this principle, that imparts to tobacco its
well known qualities; and it may be extracted from the
plant by distillation, and employed separately. Prepared
tobacco yielded, in addition to the matter above enumerated,
carbonate of ammonia, and muriate of lime.

Mr, Vauquelin imagined, that the juice of belladonna, Analysisof
from its effects on the animal economy being analogous to belladonn**
those of tobacco, might contain the acrid principle he had
discovered in the latter : but pn analysing it he found only
an animal matter, salts with base of potash, and a bitter
substance, from which the juice of belladonna receives its ;
narcotic properties.

Mr. Chevreul presented to the class a very extensive series production of
of experiments on vegetable matters. Te object o f some araere
of these ■ "^s the bitter principle produced by the action of . ,

nitric acid an organic matter containing nitrogen. He con-
ceives it ii be a compound of nitric acid and an oily or
resinous *eoetable matter: and he ascribes its detonating
property to the decomposition of the nitric acid, the foi mo-
tion of aramoniacal gas, prussic acid, olefiant gas, &c, . -
But with the amere is produced a resinous matter, and a
volatile acid, on which Mr. C. has made many experiments;
jind Which he considers as differing from the amere only by
a smalt addition of nitric acid.

Another obj«ct of Mr. Chevreul was the substances a^fj of aftj^.^j
formed by the action of nitric acid on carbonaceous or tannin.
lesjnous matters, which have the property of precipitating

gelatine

I

ISi SCtEWTinC NIWS.

fi^elatine. Mr. C. does not agree with Mr. Hatchet, their
discoverer, in considering them as similar to tannin. Re
thinks they differ not only from tannin, but from each
other; and that their diifferences arise from the acid em-
ployed, the matter from which they are prepared, and the
quantity of acid that enters into their decomposition.
Sulph. acid •^•** ^' ^^^ likewise examined the different compounds

ftnd camphor, formed by the action of sulphuric acid on camphor.
DbtiUation of Not a year passes without presenting us with some happy
•J*"**** application of chemistry to the arts, and thus affording us

fresh proofs of the .benefit, that our manufactories derive
from the sciences. Thus Mr, Chaptal has made some inter-
esting observations on the distillation of wine. The im*
provenient of this process has gone band in hand with that
of chemistry. One of the principal distilleries in the South
' of France is nothing more than Woulfe's appar.itus on a

large scale.
Ancient co- '^^^ same gentleman has analysed seven specimens of co*

lours. lours found at Ponipeia.

iStucco, & c.

Mr. Sage has examined the processes best adapted to
the management of lime for making solid mortars ; the na-
ture of different kinds of stucco ; the means of giving the
polish of marble to artificial stones ; and lastly a process for
reducing white wax to a soap.
Zinc for roofs ^^ ^^^ ^^^^ written a paper, and Messrs. Guyton and
Vauquelin a report, on the advantages and disadvantages
of rooting houses with zinc.

... , The section of chemistry have also pointed out, at the

Jn-jurious ma- , *^ ....

Dufactories. desire of the minister, what manufactures may be injurioos

to those who live in the neighbourhood ; and what measures

should be adopted, to reconcile the interests of the manu-

•fectures with those of the public^

A report has also been made on a paper of Mr. Tarry*s

indelible writ- \ . , . ^ c .- '\

ixM ink. respecting the composition and improvement ot writing ink.

The author has composed an ink, which is not destructible:
^ either by acids or alkalis; a great advantage in France,

where the practice of altering title deeds has lately been

very prevalent. It has the inconvenience however of letting

fall its colouring m:>tter too easily,
Artificial tui- Another report^ oa the artificial turquoises of Mr. Sauviac,
(^uuises. gives

eciENTirrc news. I55

gives reason to hope, that the productions of art in thii
respect will soon imitate exactly those of nature, so as to
afford us a new source of wealth.

A (Committee has also examined the late Mr. Bachelier* Preservative
composition of a preservative mortar.

The progress of mineralogy has not been great. Mr. New diamond
Guyton however has made known a new crystalline form of ^'^^' * •
the diamond, and has made some valuable experiments on
the tenacity of metals.

From the researches of Mr. Sage it would appear, that Substitute for
the chrysolite of volcanoes, when powdered, may be sub- ^^^^Y*
stituted for emery. All the artists that have used it have
expressed themselves satisfied with it.

The observations from which geology can draw the most Fossil animaK
important conclusions are no doubt those relating to fossil
animals, particularly such as have lived on the earth. Mr.
Cuvier has continued his inquiries into this subject. Jointly
with Mr, Brongniart he has concluded his mineralogical
geography of the environs of Paris; and he has since ex-
amined the bony breccice of the coasts of the Mediterranean.
These singular rocks, which are found at Gibraltar, near Bony brec- ^^
Terruel in Arragon, atCette, at Antibes, at Nice, in Corsica, '^'*' ' " ^
on the coasts of Dalniatia, and in the island of Cerigo, have
been formed in fissures of compact limestone,which constitues
the principal part of these countries, and are all composed
of the sanie elements; which are numerous fragments of
bones, and of the surrounding limestone, confusedly united
together by a brick-coloured cement. All the bones belong^
to herbivorous animals, most of them known, and even still ^.*^

living in these places. These are mingled with freshwater 44^; » 4^ - >►-
shells; which lead to the supposition, that the brecciae are
posterior to the last abode of the sea pn our continents, though
very ancient with respect to us; since we have no indication of
si^ch brecciae being fornied in the present day, and some of^
them, as those of Corsica, include unknown animals.

Bones of animals of the order glires are contained also in Bones in *11a^i
alluvial, soils. They have been found in the bogs of the
valley of la Somme, with horns of stags, and heads of oxen ;
and in the vicinity of Azof, near the Black Sea. These
bones belonged to animals of the genus castor ; some much
resembling those of the common beaver; others, which .^^

for»q

155 SCJENTlFrC IIEWS.

form a complete head, from a larger species. Mr, Fisclier,
who discoveried this animal, called it. trogontherium^ which
M. Cuvier has adopted for its specific name,
Ujy^^jj^ Remains of glires have been found also in schists. Three

Khist. species have been described, and Mr. Cuvier has seen the

figure of one, whix^h some authors consider as having be-
longed to a guineapig, others to a polecat. He could not
determine the genijs however, though it has the characters
of the order glires.
Fosalbonesof Among the fpssil bones of rumioants found in the loose
a-speoesof g^j]^ ]y|,,^ Cuvier has recognised a species of elk, different
from th^t now known. Its remains have been collected ip
Ireland, in England, on the banks of the Jlhine, and in the
, vicinity of Paris, in beds of mafl of little depth, which ap-

pear to have been deposited in fresh water. Other horns,
discovered in abundtjnce, near Etampes, in sand underlying
fresh water liipestone, prove the existence of a small species
of reindeer pot now known. Mr. C. has also observed re-
mains of the horns of the roebuck, fallow-deer, and stag,
which do not appear to differ from those of the known spe-
<ries. None are more abundant than these.
SirolHofthe Among the fossil remains of ruiniqants with hollow horns
«B»chs»uru&? },g j^j^y recognised skulls of the aurochs, found on the banks
of the Rhine and the Vistula, in the neighbourhood of
Cracow, in Holland, and in North America. These skulls
differ onl}' in size from those of the present aurochs, and
this Mr. C. ascribes to their move abundant nourishment in
the vast forests and fat pastures of Germany and Gaul,
•ndoftheori* Fossil skulls are also found, that differ from those of our
fsn^tof our domestic cattle only in being larger, and having a different
iji^ direction of the horns. These have l^een dug up in thp

▼alley of la Somme, in Su^bia, in Prussia, in England, and
in Italy. ** If we call to mind," says Mr. C. " that the an-
cients distinguished two sorts of wild oxen \n Gaul and
fhcbfactn? Germany, the urus and the bisop, shall we not be tempted
to suppose, that one of them was th^t, which, aft^r having
furnished our domestic breed of cattle, has become extinct
in the savage state; while the otherj^ incapable of bein^
tamed, still subsists in very small numbers only in the forests
pf Lithuania?"

BoTie« of the y^^e find likewise in ^he loose soil bones of the horse an4
bjMseand^ar. ^ ^^

SCIENTIFIC NEWS. 'i^$T

the boar. The former almost always accompany the fossil ' : i*ir

elephants, and are found witli the mastodontes, tigers,
hyenas, and other fossil bones, discovered in alluvial lands:
but it has not been possible to determine, whether they
belonged to a species different from our domestic horse.
Those of the latter have been obtained chiefly from bogs,
and exhibit no mark to distinguish them from those of the
common boar.

Other bones have been found, which belonged, according v s ' rf
to Mr. Cuvier, to a new species of manatee. They were in mao*tee;.
strata of a course 'marine limestone, on the banks of tl»e
Layon, near Angers ; and were mingled with other bones, some
of which appeared to have belonged to a large species of
seal, others to a dolphin.

The skeletons of three fossil oviparous q«9€l»'uped«, ^^^^^^^^^^^1;^^^
found in calcareous schist, have likewise been examined by reptiles, '
Mr. Cuvier. One was at Oeningen, on the right bank of
the Rhine, at its efflux from the lake of Constance. It had
been described and figured as the skeleton of an antedilu*
vian man, an errour already refuted. Mr. C. has shown,
that it wag a reptile, somewhat resembling the salaman-
ders, and belonging to the genus proteus.

The second, found at the same place, was of the ioa.A
genus, and approaching to the bufo calaraita.

The third, and the most singular, discovered in the quar«
riesof Altmuhl,nearEichstadtand Pappenheim inFranconia,
had been described and figured by Colini in the memoirs of **

the Academy of Manheim. Mr. Cuvier considers it as bar-
ing belonged to a species of saurien. The length of its
neck and head, its long mouth armed with sharp teeth, an<i
its long arms, indicate that it fed on insects which it cau"-iit
flyinp;; and the size of its orbits leads to the supposition,
that it had very large eyes, and was a nocturnal animal. No
reptile now known bears any resemblance to this inhabitant i.;5v * :»
of the ancient world.

In a supplement to his fossils of Montmartre, Mr. Cu- ^ . . .
vier has given a hgure and description ot an ornitholite
much more perfect than any before published. It appears
to have been of the gallinaceous order, and to have come
!iearest in size to our common quail. '

Mr!

I^g SCIENTIFIC NEW«*

FstiifiedftttlU. Mr. Sage has described some carpoliteB. One was a tcet^
nel of a walnut, found at Lons-le-Saulnier; another ap-
peared to have been the fruit of the wild nutmeg, that grows
at Madagascar and in some of the Molucca islands; and
the third belonged apparently to a genus approaching the
durio. The last was converted into jasper, the other two
into limestone. To these observations Mr. S. adds some
others, that had been made before, and concludes from
them, that the petrified fruits found in our climates are
exotic. He likewise enters into a chemical investigation of
the means by which these petrifactions have been eifected.

Order and method will always be two objects of the
greatest importance in natural history, and particularly in
botany; and accordingly the most celebrated naturalist*
New order of have made them their particular study. Mr. de Jussieu,
^ ^^' who may justly be considered as the legislator of methods

in botany, has formed a new order of plants under the
name of monimias. The genera, of which he composes it,
are ruizia, raonimia, ambora, and perhaps citrosma, pavo-
nia, and antherospermia. This order should be placed im-
mediately before the family of utriceae: but at the end of
the monimiae Mr. de J. places the calycanthus, hitherto
united with the rosaceae, which he considers as the type of
a new order, that will serve as an intermediate link between
the monimiae and utriceae.
Fructificatior* Mr. Palissot-Beauvois has studied the organs of fructifi-
Qf grasses. cations in grasses more accurately than had been before
done; and on the structure of each part of these organs
has founded characters, that distinguish them from each
other; thus affording means of arranging the numerous
species in genera much more natural than those hitherto
adopted.
N©w plant of ^''' Labillardiere has made known a new plant of the
thepalji kind, family of palms, of which he makes a genus under the
name of ptychosperma, bordering on the elates and arecas.
This plant was discovered by the author in New Ireland.
It frequently reaches the height of sixty feet, and yet its
trunk is but two or three inches in diameter. From these
proportions Mr. L. gives it the specific name of gracilis. ,It
it aatonibhing, as he observes, that so slender a tree shoulct

support

i

SClErtlFIC NEWS. 159

support itself: but we know, that all the monocotyledonous

plants have the liardest part of their wood externally ; and ; ^^ ♦^^•t

this structure imparts to them a degree of strength, which

they could not possess if their most solid fibres were in the

centre.

Mr. Lamouroux has presented to the class a very exten- Marin« plants*
sive work on marine plants. In forming one group of all
these Mr. L.'has made a useful innovation. The little pro-
gress that has been made in the study of seaweeds has pre-
vented botanists from being agreed respecting the organs
of fructification. Mr. L. not only embraces the opinion of
the male and female organs being placed in tubercles at
the extremity of their ramifications, but characterises the
different parts of these organs with precision. He has far-
ther observed, that the species growing on granite, on lime-
stone, and on sand, are always different. As to their inte-
rior organization, Mr. DecandoUe had observed, that it was
destitute of vessels, and entirely formed of cellular texture.
Mr. L. distinguishes two sorts of cells; one very long, and
hexagonal, forming the stalks, and the ribs of the ramifica-
tions ; the other also hexagons, but nearly equal sided,
and constituting the membranous or foliaceous substance.
The former he supposes are analogous to the vessels, and
the latter to the cellular texture of the more perfect vege-
tables. His researches have also led him to form several
new genera.

To CORRESPONDENTS.

On perusing Dr. Davy's paper in our present number,
and the letter from Mr. J. Davy, in which he mentions the
properties of Dr. Davy's zuthic acid, or compound of oxi-
muriatic gas and oxigen, p. 43 of our last number, J. M.
will probably perceive, that the objects of his obliging com-
munication are there answered.

To some other correspondents a similar remark will ap-
ply.

.AfET£OROLOGICAL

METEOROLOGICAL JOURNAL,

For MAY, 1811,

Kept by ROBERT BANCKS, Mathematical Instrument Maker,
in the Strano, LoI^don.

THERMO METER.

BAROME-
TER,

RAIN,

noted at

WEAl

'HER.

Day of

s

^

s

zi

APR.

cu

Lowes

the Ni

9 A. M.

9 A.M.

Day.

Night.

28

56«

5'5«

63-

47

29-60

Fair

Cloudy

29

53

50

55

46

'37

•080

Rain

Ditto

30

51*5

50-5

55-5

47

'77

•195

Ditto

Rain

MAY

1

56

57

60

52

29*67

-055

Ditto

Ditto

2

56-5

52

59

47*5

•64

•140

Ditto

Fair

3

54.

56

58

52

30-02

•040

Ditto

Ditto

4

55*5

57

6l-5

53

29'89

•190

Ditto

Cloudy

5

56

51

56

44

•72

•200

ClGUdv*

Ditto

6

48

50

52

47

30-07

Rain "

Ditto

7

53

52

53

46

2975

•scio

Ditto

Ditto

8

49

54

56

48

•81

•i6o

Cloudy

Rain

9

52

51

54

47

'56

•no

Rain

Ditto

10

55

56

60

50-5

, 74

•325

Ditto

Fair

11

56

59

62

55

•83

•070

Fair

Dittof

12

59

68

72

60

•74

Ditto

Ditto

13.

65

66

73

62

•53

Ditto

Ditto

14

65

57

65

52

•50

Ditto

Ditto

15

58

60

68

56

'7S

Ditto

Rain ?

16

6'0

60

67

57

'79

•025

Raint

Fair

17

58

61

65

55

•90

•OiO

Fail-

Ditto

18

60

64

67

58

•86

•030

Ditto

Cloudy

19

6a

55

62

50

•9-5

•140

Rain

Ditto

20

55

57

70

54

•85

•260

Fair

Cloudy §

21

57

60

62-5

55

•68

•200

Cloudy

Fair

22

60

6;J

67

52

•70

Fair

Rain 11

23

57

57

64

52-5

•81

•300

Ditto

Fair

24

58

62

66

57

•91

Fair

Cloudy IT

25

6l

64

69'5

58

'99

•000

Ditto

Ditto

S6

65

68

74

62

30-04

Ditto

Ditto**

2*940 Inch, since last Journ.

* Boisterous day. f Lightning. t Thunder, 3 PM.

\ Lightning— Tremendous Thunder and Lightning at 4 A. M. 1| Ditto at 8 P. M.

^ Lightning. ♦* Ditto.

JOURNAL

OF

NATURAL PHILOSOPHY, CHEMISTRY,

AND

THE ARTS.

m

JULY, 1811.

Article i.

On the Manufacturing of Thtisad, and Articles resembling
Flax, Hemp, Tow, and Cott&n, from the Fibres of the
common Nettle. Bif Mr, Edward Smith, of Brentwood ,
Essex%

I

SIR,

iPi.

HAVE the honour to transmit to you a short memoir on Uses of the
that hitherto much neglected and despised vegetable the "**"^*
nettle, with the general useful purposes to which the pro-
duce thereof may be applied. If yon think it will merit any
claim to the attention of the Society, I request you will do
me the favour to lay it before them.

My attention was first directed to this matter about the
year 1793, but from many impediments no favourable op-
portunity presented itself for particular investigations till
about the year 1800, since which time, I have annually se-
lected a few of the nettle plants from their various situations
at different periods, in order to ascertain the state most

* Trans of 'the Soc. of Arts, vol. XXVIII, p. 109. The silver me-
dal WIS voted to Mr. Smith.

Vol. XXIX. No. 133— July, isn, M c©^-

lS2 MANUFACTURES FROM NETTLE FIBRES.

congenial to the process, and that most suitable to the dif-
ferent purposes to which I thought them applicable. The '
result of my experiments has deeply impressed upon my
mind, that they may be made subservient tonational utility,
particuUrly at the present period, when our foreign com-
merce is so generally impeded, and in consequence our sup-
plies of foreign hemp and flax nearly annihilated.
Its abundance. I beg leave to observe, that the growth of nettles is ge-
neral, in every country, particularly in strong fertile soils,
that on every bank, ditch, and place, which cannot be
brought to tillage, they are produced in such abundance,
that the quantity, if collected, would be of «^reat magni-
tude. 7^,
Ptaces adapted , The growth of them might be encouraged in such waste
to us grow . p]3j,gg^ QP Q^ yj^g|. quantity of land of that description might,
at a moderate expense, be made to produce a valuable crop
of a useful article heretofore regarded as a nuisance. The
shady places in woods, parks, and coppices, are particularly
favourable to their growth ; I have found them in such si-
tuations in the greatest perfection in point of length and
Answers every fibre. The harl, or iibre of them, is very similar to that of
purpose of ^jemp or flax, inclining to either according to the soil and
different situations in which they grow. I have ascertained,
as far as I have been able to proceed, that they may be sub-
stituted for every purpose for which hemp or flax is used,
from cloth of the finest texture down to the coarsest quality,
such as sailcloth, sacking, &c., and for cordage.
Material for Another very material use, the magnitude of which, I
paper. trust, will be duly estimated, is, that they may be applied
to the manufactory of paper of various qualities. The im-
pediments to foreign commerce have lately deprived us of a
supply of linen rags, and occasioned a general use of cotton
rags in the paper manufactory, which is injurious to the
preservation of the most valuable works in literature, to the
truth of which the observation of every one must bear testi-
mony, who has attended to the depreciated quality of writing
and printmg papers.

That the produce of nettles, and the refuse of them from
the manufactory, may easily be convei-ted into writing,
printing, and all inferior sorts of paper, I feel confidently

assured.

*•

MANUFACTURES FROM NETTLfi FtBRTIf. l63

Assured. For the purpose of writing; and printing paper
they mig-ht be gathered twice in one season, as for these uses
th^ length of staple is not required, and the fibre would be
considerably increased in its fineness; and in point of co-
lour, either in the refuse or unwrought state, the chemical
process of bleuching now in practice would render them a
delicate white,

I have in possession some samples, which have gone
through a succession of processes similar to what are prac«
tised on hemp and flax ; and 1 have, without the aid of any
im[)lemeai^, brought them to a state of preparation ready
for the hackle ; but for want of that, and there being no flax
or hemp manufactory in this neighbourhood, I have not
been able to proceed farther, but 1 judge that they are suf-
ficiently advanced so as amply to evince the practicability
above referred to.

If you think proper, I will transmit the samples for the
Society's inspection, and give any farther information in i;i^
power.

Permit me the honour to subscribe myself. Sir,
Your most humble servant,

3farcA 24, 1809. EDWARD SMITH. gfL'^ ^

SIR,, * ^ ^^•l

I am much obliged to the Society for their reference of ^'j**®° J<^ . i
n 1 ■ ^ • *i subject offered i

my communication to one of their Committees. About ten by the Society

years subsequent to my first observations, and three to my *' HaSrlem.
first experiments, I observed the following paragraph in
the Chelmsford Chronicle^ November 25, 1803. " The
Society of CEconomy, at Haerlem, has offered prizes for the
best memoir as to the particular species, the season for
gathering, and the manipulation necessary in preparing
nettles for use," This is the only account I have ever seen
of them, and shows that such a matter was regarded as de»
serving the attention of that Society ; but as I from the first
had it in contemplation to present my observations on th^
subject to the Society of Arts &c., and thinking the matter
of great consequence, and wishing my own country to be
benefited by it, I declined answering the Hacrlexn advertise-
ment. ^^,

^^m'

#'

^ISa manufactures from kettle fibres; , . .

My discovery of the properties of the iifettle is original,
and arose entirely from my own obsei vations on the appaf-
reut resemblance to hemp and flaxj which I remarked they
had when growing. I now transmit to yoa some samples, tt^
different states, for the Society's inspection.
^ • ihave the honour t© b^i ivith grtat respect,

Your most humble servant,
Ma*-cA 28, 1809. '^ EDWARD SMitH.

SIR,
Coarse ^arn & 1 have Viow tke honour to transmit to the Society my
flax froni net- faither prdgvess, viz. A sample of yarn preparea from the
^^'' 'hoarsest part of the nettle product, which I deemed less lia-

"ble 16 be injiired for vVartt of knt^wledge in tBe manufactur-
ing\han the finer qualities. SfnC^ my former letters 1 have
been bleaching some df the nettle flax, and have brought
it tcf hii'good fi coloiiH'thtit a prepafSiion from it wbuld pro-
duce paper perfectly white, and I have cafised a sample of
yarn to be made from fche nettle produce, both of which 1
have sent. ^ *

'faperfrom I likewise enclose an improved specimen of paper made

tbem. frtim the same substance ; also a preparation f<* paper, a

part of the same sample the enclosed was made from, which
is, of course, much inferior to what would be c^dne by a
paper manufacturer. These samples having been made by
such rough instruments- as were corfttructed by my own
hands, and which of course the Society will consider.
1 remaitl^'resiiectfully, Sir,
"^^!? " "" Your obliged humble servant,

Mv. 18, 1809. - EDWARD SMITH,

'The following ^pMmciis,' produced from Nettles by Mr.
Smith, are deported iii the Housekeeper's Office.

Aiticles pro-#; , Samples of the ^bres, in theif rough state, res«|^bling,
ducei fr »iBi^ diflereyt kinds of hemp and flax>

Samples offthe fibres equal to the finest flax, and re-
markably strong in texture.

.Samples of very.stro|*g yarn, prepared from the coarsest

Samples

neitlc:

t

1r

y^t^Uf^CTUll^S FHOM NETTV?^ FIBRES. \65

I^amples qF c/^a^se paper, prepared frofn the rough ref^s^ ^

fibres.
^ ►Samples of the coarsp fibres bleached white. Jtt|e A^nit

Samples of a co^/se substance reseml^liog cotton prepare^
from the bleached coarse fibres.

Samples of white paper prepared by him fr^m thCilastw
mentioned &ubs|ance. .;.

Mf, Smitii*^ Process for preparing various Articles from
- '^* '^^ Netties.

The kind 0f nettle capable of beinjj; manufactured into The kind of
cloth, &c., it is scarcely necessary to san^is that whieh io-^
general is denominated the stinging 'nettle. The most
valuable sort, which many years practical experience buBf- Best sort,
furnished me with a knowledge of, in regard to length, sup-j, ^ y^tk

pleness, fineness of the lint, brittlenesa of the reed, .which JfeHB||
dresses most freely, with less waste of fibre^ and yields the ^^^^P'
greatest' produce of long and fine strong harl, I have found
growing in th^ bottom qf ditches ^impng briars, and, in
shaded valleys, Nvhere the soil bai bee^a blue day or stropg *
loam, but from which situations I have selected spme which
have measured more than twelve feet in height, and up-
wards of two inches in circumference. Plants growing iq, '^
the' situations above. despribed are in general from five to *Sfe
nine feet in height, and those growing in patches on a good *" ^^

sipil, stiMi^ingthicIs, and in a favourable aspect, will average
in height abovU five feet and a hajf, will work kindly, and > 1

tlje stelftp are thi<;ivly clothed with lint. Thos^ ttiat grow Worst nettles,
in poorer soils, and iu less favour^)L|le situations, with rough
and \v9p4y stems, and have mapy lat,er|»l branches, rua ^
pjuiah to §eed, are stubborn, and y^jrjt less kindly; tiiey '^ ' ^jp^j^
prodijce lint more coarse, harsh, and thjn. In every situa- Marks of th«
lion gnd ^l^^rent soil I have expprieqc^ the m^^ pjoduc-^'-'**'
^ft.OpttJp» .t9 be those which haye the smoothest and a^Qft
coDpave tubes, the largest joints, the fewest leaves, and
which produce the le^st quantity of fe^d. s.

In gathering thpoi, as they are perennial plants, I have They should
pri^erred the modje of cutting them dov«» ipsteacj of pulling ^^ ^ut.
them up by the roots. This i recommend to be the prac-
tice, with a view to pbtain a second propvrherjj ibesitifutions

will ^

l66 MANUFACTURES FROM NETTLE riBRES,'

>t trill allow of it, and to secure the propagation of them the

suhseqnent year.
Time6ff»- The most favourable time for collecting them is from the

^"^* beginning of July to the end of August, but it may be conti-

nued even to the end of October, only the lint of those
which remain growing to that time will be less supple, and
will not work so freely ; and if the season happens to be un-
favourable, it is probable there would not be sufficient time
to steep and grass them, in which cas^they shoiild be dried
by the heat of the atmosphere, or if the state ofjthe weather
would not permit of this, then by means of artificial heat;
and when dried they should be housed ©r stacked till the
spring, when they might successfully undergothe same ope-
ration of steeping as those of the first collection. Such as
grow in grass fields, where the grass is intended for hay,
should be cut when the hay is cut, in order to prevent their
being spoiled by the cattle when feeding; the harls of
which would be fine in quality, and well suited to be
wrought up with the second crop, and which crop may be
obtained afjter those of the first cutting, where the situation
^ will admit pi their being preserved. The fine quality of such

I ascertained last autumn, and found the height of them to
average three feet and a half; they were gathered the latter
end of November. The following are the processes «4opted
by me. '■ • ■ ■ ■' 'i '

rreatment After the nettles are gathered they should be exposed to

after gather- the atmosphere till they gain some firmness, in order to pre-
vent the skin from being damaged in the onerations of dress-
ing off the leaves, the lateral branches, and seeds. Ttiis should
be done a handful at a time; and afterward they should be
sorted, viz. those which are both longand fine by themselves^
those which are both long and coarse by themselves, and
those which are short and coarse by themselves; then made
up into bundles as large as can be grasped with both hands,
a convenient size for putting them into the water, and
taking them oijt ; a place for this purpose being previously
prepared, either a pond or a pit free from mud, or a brook
<>r river. The bundles should then be immersed, and placed
aslant with the root end uppermost, and to prevent thei»
Hoating CD the surface some weight should be laid upon them.

ing

w

MANCFACTUliB^ FIlOM ITETTLE FIBBftS. 16)

The tirae required Yof steepinoj them is from five to 'eight Steeping,
days; but it is better they sljotald remain rather too long in
the water than too short a time, yet great care should be
taken that they are not overdone. When the fibre approaches
to a pulp, and will easily separate from the reed, and the reed
becomes brittle and assumes a white appearance, this opera-
tion is finished,

^;. The bundles should then be taken o'nt singly, very care- Grassing.

^IPfully, to avoid damaging the fibres, and be rinsed as they
are taken out of the water to cleanse them from the filth
they may have contracted ; they must then be strewed very
thin upon the grass, and be gently handled. When the
surface of them is become sufficiently dry, and the harl has
obtained a degree of firmness, they should be turned repeat-
edly, till they are sufficiently grassed ; the time required U
known only by experience, so much depends on the state
of the weather during the process; when they are suffici-
ently done, the harl blisters, and the stems become brittle;
they must then be taken up and made into bundles, and
secured from the weather.

The harl is now to be separated from the reed, after the Separation of
manner practised on flax and hemp, either by manual ]a- ^^^ ^"^*
bour or machinery now in use in those manufactories. This
operation was performed in my experiments by hand, and

, with implements constructed by myself, but which I con-
sider too simple here to describe, .
The harl being separated from the reed, it requires next Dressing. f
to be beaten, that it may become more ductile for the ope-
ration of dressing, which may be performed with such im-
plements as are used for dressing flax or hemp.

This operation being accomplished, the produce of the Spinning,
nettles is arrived at a state ready for spinning, and may be
spun into various qualities of yarn, either by hand, or by ijjf

machinery constructed for the purposes of spinning flax or ' ^

hemp; and this yarn may be successfully substituted for m

the manufacturing every sort of cloth, cordage, rope, &c., ^' ^

which is usually made from hemp or flax, and is particu- ', {?

larly calculated for making twine for fishing-nets equal to Twine for fish-
^be Dutch twine imported for that purpose, the fibres of the '"8 nets.

iiettlci

*--«.

^m

168 MANUFACTURES FROM NETTLE FIBRES.

nettles being stronger than those of flax, and not so harsh
sm the fibres of hemp.
Refuse. ■ ' ^p the coviia^ of my experiments on nettles it often oc-

curred ^q nne, that the ref^e, and such parts as were da-
maged In the different procejsee;, with the nnder-growth,
nji^ht be applied to useful purposes, and in addition to the
nettle manufactory, as applicable to the purposes for which
hemp and flax are used. Another source of productive
labour of great magnitude would-be d^r^iyed from a
new subst*n|:e, capable of being converted into ^
many bentiicml uses, if my, speculatsons sh0uld.be finally
accomplished. In contemplating these subjects, I was in-
Paper made duced to believe the refuse aid mjdei-growth might be
irorn I . converted into paper of various sorts, according to the

changes they might be ny^^det^p ii5ii(;i^rte,^j ffotn the se-
veral operations Lictressaiy to red^icf them to a proper state
for this use; h-.vhig freqnpniiY observed, with ^?gret, the
deterioration in the qusdity of writing apd printing paper,
OQcasioned by the use of cotton rags in the pappr mfinufap-
, tory ; which evinces itself even to the most superficial ob-
server, who may only casually open many of the modern
publications, and which must be admitted is of .the utmost
moment, as it endangers the preservation of wurl^ of litera-
ture. Bein^ convinced of the superior streni>th ,pf nettle
Advantagesof substance, I thought, could my speculations be reduced suc-
this. cessfully to practice, it would not only remedy this great

evil, and operate as an antidote to the use of cotton rags in
that part of the paper manufactory, but eventually effect a
reduction in the prices of books, which for some years^hjive
been rapidly increasing, and are now become excessive, 40
the great obstruction of disseminating useful knowledge
among mankind, and contribute to the diminution of qur
/ exports in that material branch of commerce.

In addition to the abov£ incentives, the consideration 4>f

Farther mo- the high price of paper, chiefly occasioned, as I conclude,

tires. from the extravagant pricve of linen rags,and the impediments

to tlae p/ocuring a foreign supply oi- ttiem, »ri«ingfrOfl? the

circumstances of the times; and seeing that the nse ot linen

cloth i« iu a great measure snperseded by th^ very gjeneijal

introduction

il

MANUFACTURES FftOM NETTLG FIBI^K^. -f^Q

introductioq of eloth naaililil'actured From cotton, which con-
sequently must materially diinii»ish the supply of linen r4^,
and probably, in process of time, from the inc'reasiutr sub-
stitution of cotton doUi for lin<^n, linen racrs, pHtticiiWy
of tlje finer qualities, may be totally annihilated., lir^d by
all these consicJerationa, ivhich \\'ere forcibly improsged Ofi
my raiud, and feeling assured of tl^e practicability of r<^doc-
in^ the substance of nettles to a stut/e necessary to the pro-
duction of p«ii|)«r, and confident in the superiw strena^tU of
such paper, if it could be manufactured froip a snbbtaocr;
so substuntialj I was most powerfully impelled to attempt to
reduce to {M^^ii<9|:ijce what in theory l lia4 so vvarwiy che- "

rished. The attempt v»'as arduous, not only from Ufi en-
tire want oi jvuowledge of the manufactory, and of the ne-
c^ft^ary utciwiU, Jjut 1 was destitnte of any proper impit*-
mant to en^ge in the iindeftaking vvith anj'- probability «ff
success; hoping- however by perseverance to succeed, I pri|-
ceeded, M«J found on my first rough trial my fixppc^ations . ^b^f/

Thf^ «ii»ost fjivour^ble cpp^iti,on,pf the V*-^* witlj.fi vji^^f ^ PrepaTati9n ^
the paper manufa|ct<|ry, is tp begjn vvit^- i* after 4L^« hacjsjeij ; p,*'^"'' ^
in ordei- t|)at the fii^res i^ay be,(^(ycsited of th^ skins which
enclose tlMJip, as, whpn it i§i^^^tep|[|€fj, t^^.muke white p^ippr,
iiavjr^ gone tliion^bstiiat proc^Sj'it would Greatly facilitate'
the bleaching, and be t!,«: more easily disencumbered of the
gross particles.

V\ h"" ^ -'r'.iify as my opinion, that the fibics c. lietiles jHJ

ftli(*'jl sed the same as for yam, prey>ou« to their ^Wi

being prepai-ett with a view to the making- of paper, I wish
not to be .nn,derst(.od to convey the,ideati]|pt, the operation
cnnnot be dispenied wi4^ Jc)ecause I (,on<;eive, tbit,fl^ the
aid of such machinery as ?8 in use with t^e paper manufac-
turers, or by some improvements therein, tliey ^nij^ht be
broaght to a pulp easily, even when t':,-.- . Ules ure,^4;iSt
gathered, should it^tptb a view to saviiio- of labour, be
deemed ne<;es5a4y; butrthe practicability of this 1 leave to
the experience w hicl^ time may hereafter afibrd.

My operation of bleaching ^he hbres for paf)er %vas per- Bleaching,
formed on llie grass, which I jdeem preferable to th^ new
mode of bleaching with water irflpreguated witji air by

Xj, means

^

:JJ^ MANrtACTUEES FRSM NETTLE FIBRES.

means of oxigenated muriatic acid gas; because the old
mode of bleaching on grass weakens the strength of the fibre,
leaves it more flexible, and thereby expedites the raaceni-
tion, which in some degree compensates for the time it re-
quires longer than by the chemical process. But for
bleaching of yarn or cloth made of whatever substance, the
chemical process, if scientifically conducted, experience has
convinced me is preeminently superior, as it gives additional
strength to the yarn, greater firmnes to the texture of the
cloth, and isHn immense saving of time, labour, &c.
Subsequent After the lint is bleached it should be reduced to a pro-

jnanagemen , ^^^ length for paper, and then macerated in water after the
manner of rags, and undergo similar processes till the sub-
stance' is converted into paper, which may be easily accom-
plished by manufacturers, and the substance of nettles made
to produce paper of the first quality and the most substan*
tial. ■

JMode in which In my process the lint was reduced by scissors to particles

specimens of gg jyjjnute as was practicable with such an implement ; then
paper were . f ' *

i)rpduced. it was macerated in cold water about ten days, and brought

as much to a pulp as could be effected without the aid of

grinding, &c. Being a stranger to the composition used to

procure the adhesion of the particles, if any is used for this

purpose, I tried several glutinous substances, none of which

answered so well as a solution of gum, but I am well aware

this cannot be generally used, being too expensive.

After the pulp was impregnated with the solution, I then
spre;^ it thin on a wire frame of my own construction,
which process, except drying it, with me was final. Not
l)eing possessed of the means of pressing the paper any
more than grinding of the lint, and for want of the film
which adheres to the lint being stressed off, I could not com-
pletely destroy the colour, so as to produce a clear white
without picking out every discoloured particle, which I so
well accomplished, that when 1 had reduced the staple in
length, in this state it was perfectly free from colour; the
deterioration which ensued when converted into paper was
occasioned by the solution of gum.

My processes were the fruits of my own conceptions, and

} desire it may not be understood, that I presume to recom-

^% roeod

#

IMPAOVED RBAPINGHOOK* 171

mead them for practice, bein^ conscious, that the manu-
facturers of paper, hemp, and flax, from Analogy, are pos-
sessed of the knowledg^e of operations and means more
consonant and infinitely superior.

These several mannfactureB from the new substance of
nettles, patronized by the stimulating approbation and re-
commendation of the Society of Arts, &c., I with all due
deference venture to predict will rapidly increase the capital
of those individuals who engage therein, afford new em-
ployment to the poorer classes of society, and become a
new source of wealth to the oation.

■' EDWARD SMITH.

April y 28, 1810,

II.

Description of an improved Reapins^hook for Corn. Sy Mr*
Joseph Hutton, Jun. of Ridgway^ near Sheffield*.

SIR,

m^

,T a time like the present, when all foreign supplies of A grlculturil

grain are cut off, nothing can be more acceptable to the l'"?'^^^^™^"^
" /. 1 J- • J • . • "ijportant.

public than' usetui discoveries and improvements in agri-

ciilture, 1 am tbeT«^<We anxious to contribute, in some

degree, to this end, by sending some remarks on reaping VM

the harvest, accompanied with my new-improved reap- ^

hook. * '

1 have, for the last eight y^rs, had an opportunity of Reapitj^.
inspecting the different modes of reaping the harvest in
many parts of Great Britain, and I have also had informa-
tion on the subject from various parts of Europe and Ame-
rica on respectable authorities.

I will first endeavour to describe the different kinds of
implements used for this purpose, some of them being em-
■ ployed in one part of the kingdom, and not in another.
•A ' . .. , ■ .

♦ TriTM.-of the Society of Arts, toI. XXVIII, p. 54. The silver
ne4al was -roted to Mr. Hutton for this improvement.

, The

«•

J ^2 IlfFlMWED E?APIN9^00K.

S'.ckle. Jl?e ^ckle i« pf tlj(9 gr^v^test ^ntiquity^ though itj^ tjse ts

]^w i»uch i)pon thje Recline iu j^nglaiid. It is alniost in the
ibrw 0f. .^ Ijalf circle, from tyyeuty to thirty inches long,
about three fourths of an ia,G|i. broad, with teeth cut,iu %\ip
edge frpra twenty to 4)^if|^y^i^j,^n inch, inpjining from the
hant]l^ tj» the point, i .*! " ^i:

Sith«. The fjth^ is an in^trufflent ^^j. generally ^^^pwp, ^s to

neefj no description, farther than that som.e pre made longer,
and pthpr^ f^foader, a$ necessity or paprice requires.

Reapingh«ok. The Qomijaon reap-hook is a half-circular piece of if.op
and steel, from twenty to thirty inches long, about pne in<;h
and a half broad, aad has a smooth even edge, like that of
a sithe.

Badginghook. The badging or baging-hook is broader than the com-
mon reap-hook, particularly at the point, where it is most
used, and straighter than the sickle or reap-hooks generally
are.
'. Upeof ihe The reaping of wheat with the sickle is yet continued in

;^*|#iifcie.' Yorkshire, Durham, Westmoreland, Cumberland, Lan-

"*' cashire, Warwickshire, Leicestershire, Northamptonshire,

Jlntland, Nottinghamshire, and part of Lincolnshire J it is
performed by putting the sickle into the corn with the right
hand, aj^ee^ing j^ with the left hj^nd, gathering the porn
into the elbow of the ^ic^y^'ne^r the ji^ht han^, holding the
corn fa^t jwitii the lpi,'t hatidf «»^t»l H isi cut, t^ep ,\\^e p/ergofi
• — . repeats his cj^tting uijt-il hp.ha§ obtained a l#rge hpncjfuj,

which is generally one thii'd fif ii ^heaf, which he hy^^i^Xkp
straw binding ready prepare^, j^^ > r' -'t

t'seefdie The common reap-hook is used in the manner abovje

rei:fin^l>ock. gpeqfj^d, bplt \ts ejects are far different, 4hp sickle, j^nying
a toothed edge, does not cut $AJch stem^^^^ are not imijiedi-
;^t«.ly collepted ifito th;e left ha^fj ; fpi' it i^ hnposgiiblp to p«)J-
Ifct all .w.l;i^|.e disp^atpj) is. required, particularly in tjiip
straggling crops, for the teetl^ pf the sickle bein^incline/d, it
i^ not so fh.'f'P ip cutting frori> point to handle, as ffom
i^^ndle tp point, ^hich js evident f^-onj a feel yvitjj the finger.
The r^pp-hoplf , J)fiying fi ^nfipptji even efjae, PW^s l^oth ways
alike, and cuts the straggled stems before they are collected
in the gatfiering hunc^, conspqueptjy the Ipgs of gr^in is
great. The hpok is id}owed tp perform its .work with more

-nA.

t^ase

I

IMPROYED REAPINGH^OKi' |yj

«ase than £he sickle, whicb perhaps deed ti tits fdr \U now
being so ^^neral, nothing else being used for cutting vrhedt
in the following counties:— Cornwall, D^von* Dorset, So-
merset, Monmouth, South- Wales, Hereford/Wilts, Hant^
B^rksihire, and part of the adjoining counties; it is also
much used in Norfolk and Lincolnshire, also Northumber*
lapd, Westmoreland, and South of Scotland. It has lately
been introduced into the North of Ireland by Irishmen who _^

have laboured in Scotland, likewise into the Indies for ^

cutting rice.

The badging-hook is used about London, and in the Use of ihe
A\^e8t of England, its work is performed by the man holding badgin^hook,
the hook in his right-hand, and while, with the left, he re-
clines the stems intended, to be cut upon the standing corn,
which supports it when cut, he repeats hid cutting from his
right to his left hand, and collects it from his left to his right,
which is almost a sheaf.

Badging is an expeditious mode of reaping; the corn is This prefeni*
cut very lov/ as if mown, Snd answers where straw is vala- ^^^ ^® ^^
abl^. It may be said, that badging produces more manure,
from the greater quantity of straw collected ; but in stiff
clay lands a longer stubble is perhaps necessary to be left,
to render the land lighter for the following crop. The
badging-hook is ald(^ used for cutting oats in Lincolnshire *
and Statibrdshire, aild where labourers can be procured, is
preferable to the sithe, being expeditious in its work, and
less loss attending its use, the corn is gathered in straight
regular order, which i^ not the case with the sithe ; for the
sithe requires at least two persons to follow it to bind the
corn in sheaves, besides raking theJ stubble. The corn
after the sithe lies in very irregular orSer, and holds more
moisture in wet weather j Ibesides, the sithe is^destructive to
the ripe corn, for its heavy stroke strips from the entangled
stems the best and ripest grain.

The labourer seldom considers the interest of his employer,
but generally uses such a tool as will do the work with most
eas^ to himself.

I oflfer my improved reap-hook to the public, with a view improTed
to prevent the loss of ^ain, and at the same time to be u^ed reapingho»k.
with ease by the laboured It has a ^mooffi edge like the

r^ap-hook

174 IMPROVED REAIPIKOHOOS.

reap-hook, from the handle of it towards its middle^ where
the corn is gathered ; the other part has a toothed ede«e, like
* sickle, and it will not scatter the corn so much as either of
the other implements.

I shall furnish certificates to show, that I am the inventor
of it, and that it has considerable advantages in general use.
It is a great preserver of corn, in harvest, where it is strag-
|[led much from heavy rains.

I am, Sir,
^ Your obedient Servant,

JOSEPH BUTTON, Jun.

The following certificates were received.

Tcsiimoniesof A certificate from Mr. J. Turner, of Ridgway, dated
itsutUity. Octobers, I8O9, stating, that in the year 1805 he had
made two dozen of improved reap-hooks by Mr. Hutton*»
instructions ; that they were the first he ever knew to be
made upon this plan, and that in the present year he and
others have made thirty-five dozen for him.

A certificate from William Taylor, of Summit Lodge, in
Yorkshire, bailiff to G. F. Burton, Esq., dated September
29, 1809» stating, that after a few seasons experience, he
finds Mr. Hutton*s reap-hook preferable to any bther, from
the nature of its edge ; that the labourers under his sup^-
intendance used all of this sort the last season, and that it
is found to be a great saver of corn.

A certificate from John Boothe, sithe, sickle, and reap-
hook manufacturer, Ford Mills, near Sheffield, dated Oc-
tober 12, I8O9, stating, that Mr. Hutton's reap-hook is
certainly superior to the common one, and that public
opinion confirms it as such, for there has been a great de-
mand for them the last two harvests.

A certificate from Mr. Edmund Liftlewood, of Dent
Hall, near Dronfield, dated October 15, I8O9, stating, that
Mr. Hutton*8 reap-hook is superior to the common ones
now in use, especially in the last harvest, in which the crops
have been remarkably straggled, and bad to reap, owing to
the heavy raint and winds. That the common reap-hooks

cut

NEW ENGINE. 175

cut while putting in, before the gathering hand has collected
the stems together, and consequently many drop and are
lost; which is not the case with Mr. Hutton's new-invented
reep-hook, which does not cut before the stems are collected
together in the gathering hand.

III.

Report 0/ Messrs. De Prony, Charles, Montgolfikr,
and Carnot, to the French lusiitute, on the Invention of a
new Engine, by Mr» Cagniard-Latour, /ormer/y Pupil
at the Polytechnic School*,

0

T is known, that all bodies immersed in a fluid lose a Principle o£ a
part of their weight equal to that of the fluid they displace, ^^^ engine.
On this principle Mr. Cagniard's new engine is founded.

The first mover in this engine is not the vapour of boiling f<i„t nxover,
water, as in common steam engines, but a volume of air,
which, being conveyed cold to the bottom of a vessel full of
hot water, is there dilated ; and, by the effort it then makes
to rise to the surface, acts in the manner of a weight, but in
a vertical direction, agreeably to the principle mentioned
above.

This mover, once discovered, may be employed in differ-
ent ways: the following is that of Mr. Cagniard.

His machine, properly speaking, is composed of two The machine
others, which have perfectly distinct functions. The object compoicdof ,

of the first is to convey to the bottom of the vessel of hot * .

11 /» 1 1 . rr^, /. 1 answenng diP-

water the volume of cold air necessary. That of the se- ferent pur«

cond, to apply the efibrt, which this air, once dilated by P***^^-

heat, makes to reach the upper surface of the fluid, to the

eff^ect required to be produced.

For the first purpose Mr. Cagniard employs the screw ofThe first the

Archimedes, If such a screw cause a fluid to ascend by ^^[j^gj^^'^"

turning it in one direction ; it is obvious, that it will cause it

te descend, if turned in the contrary direction. If then it

• Journal d« Mines, vol. XXVI, p» 465.

'f

m

IjS JTEW ENGINE.

be inltnersed in ivater, «o that only the opper part of its
spiniJ remains in the air, it ought, whin turned in the con-
ithirh convey s^trary direction, to cailse to descend to the h^ttori of thi»
tom'^of^w^ser- Water tht air thtit it takefe ititoii(»» wppef piVt in every turn,
^ou of water. This is precisely what Mr. Oaguiird's raachiae does. The
air he wants is first conveyed to the bottom of the reservoir
of cold water, in which the screw is immersed ; and thence
X it is convrjed by a pipe to the bottom of the vessel of hot

^ water. The heat of this water immediately dilates it, and

thus creates the new power, which is to act as the first
m6*er. In this way the first object of the machine is ac-
complished,
▼hence it rises The second, as we Tiave said, is to apply this new mover
^'buckl^s of" ^^ ^^^ *^^^^^ ^° ^^ produced* For this purpose the author
a bucket employs a bucket wheel completely imiiiersed ij^ the vessel

wheel in hot ^f ^^^ water. The air, diliited and collected at the bottoni
Water, • , •

of the vessel, finds a passage contrived so as to guide it

under thofee buckets, which have their mouths downward.
The ascensional force drives the water out of these buckets,
and the side of the wheel ort which they are being thus ren-
dered lighter, the wheel turns continually like ^ common
bucket wheel,
iheinotionof This wlieel, beirig set in motion, is capable of traiisrtiit-
•which is ap- tincr its action td any other movable machinery,* either by a

plied to the , , , , i • • i t i*/r

purpose want- toothed wheel and pinion, or any other means. In iYlr.

«^« Cagniatd^B macljine the ^ffet!i prd^uced Consists in raising,

by means of a dotd fixed to the a:ns of the wheel, a weight
The effect of of fifteen pounds, with a uniform velocity of an inch in a
thfefiVst inoTter g^cblid, while the moving power applied to the fcrew is only
qrintupied. equal to three pounds with the same vel6city. The effect
of the heat therefore is to quintuple the natural effectofthe
^^ ^ moving p'ovver.

Pa^of this ef. It may be conceived, that, the moving power being quin-
fect taken to tupled, we may take from this t^ffect a sufficient moraen-
p"ar^of the *"°™ ^^ supply the oViginal po'wer, and still there will remain
power that ij^t our disposal four times the original power. This in fact
is ddf\k in Mi-. CagniarcTs machine. By means of a crank,
he Forms o comriiiiiiication between the axis' of the v(heel ■
and that of the screw, so that this turns as if it were moved *
by an external agent, a'M consumes' by its molioa a fifth of I
/a *. ^^^^

first sets it in
motion.

KBW cngihe. Ijy

the iflomentum of the moving power. The remainder
serves to raise a weight of twelve pounds with a uniform ve-
locity of an inch in a second : that is to say, the machine
continually winds up itself, and leaves a disposable power,
equal to four times what would be necessary in an external
agent to keep the machine in motion.

It follows from what has been said, that, in the machine
of Mr. Cai^niard, the heat at least quintuples the volume of
air employed in it; since it is evident, that the effect pro-
duced must be proportional to the volume of this air dilated.
I have said at least, on account of the faction to be over- The fHction
come: but this friction is very trifling, because both the ^^""y *"^'"8»
screw and the wheel, being immersed in water, lose a con-
siderable portion of their weight, and consequently press
very little on their pivots. Besides, the movements are slow,
and not alternative, and there is no jerk in them ; so that this
machine is free from those resistances, that commonly con- and wear but
sume great part of themoving power in others, and accele- s^nall*
rate their wear.

We do not look upon the machine of Mr. Cagniard as It may be use-
art object of curiosity merely: it may be useful under |JJ ^^'JjJJj^^^g'Jj *,
various circumstances. As it produces its effeft in a body ations.
of water heated only to 75° [l67°F.], or even less, it affords
an opportunity of turning to account the hot water, that in
various manufiictories is thrown away, or runs to waste, in
saltworks, for instance, the ebullition of the saline solution
might be made, by means of Mr. Cagniard''^ machine, to
work the pumps for filling the boilers : in ironworks the heat'
of the furnace might be made to work the bellows : in com-
mon steam-engines, which, like that at Chaillot, furnish
a large quantity of very hot water, an action might be ob-
tained equivalent to that of several men, or horses: in fin^^
in baths, distilleries, potteries, limekjilns, glasshouses, foun-
deries, and wherever there is a production of hot water, or
of heat, advantage might be made of Mr. Cagniard's nitf^
chine. This machine, which, as has been said, is liable to
very little friction or want of repair, has also the advantagie*^
of being easily managed ; and when its action is suspended
for a time without extinguishing the fire, the beat is not

Vol; XXiX.-.JuLr, 1811. If' lo«:

178 I*EW ENGINE.

lost: for, as the water is not boiling, the heat accumulates

in it, and furnishes afterward a more powerful action.

The screw of. .The &crew of Archimedes, employed in this machine,

Archimedes produces the effect of a pair of bellows, and mieht be used
may be used » ^ . t i • 7 i l

in this way for as such in a foundery. It may even be considered as the

blowing !ar?e y^^g^ ^hat is known, not only from its simplicity, solidity,
fires with great , .,.1 . r • •

advantage. and constant action, but from the saving of power in its use

compared with any other machine employed for the pur-
pose; foj? the screw becomes very light and very movable by
its immersion in water, so that the friction of its pivots is
next to nothing.
The machine Mr. Cagniard has likewise applied the action of this ma-
m^i!ie wat"^ chine to a body of mercury. As its mechanism requires two
by means of fluids of unequal densities, he has merely substituted mercury
mercury. ^^^ water, and water for air, retaining the same construction
as is mentioned above. The result is a very simple hydrau-
lic machine, which, without valve, stoppage, or action of
fire, being &vt in motion by any external agent, as a man or
a stream of water, gives a continual flow of water at a height
fourteen times as great as that of the column of mercury, in
which the screw is immersed. This height may even be
increased at pleasure, without altering that of the mercury,
by combining the action of three fluids, mercury, water, and
air. For this purpose, instead of raising a column of water
alone a lighter column is formed by a mixture of water and
air. This mixture is effected of itself, by disposing the
lower part of the pipe that contains this column so as to
leave its opening partly in water, partly in air, according as
'^ we would have more of one fluid than of the other, and con-
sequently occasion the rise of the mixture to a greater or
less height. It is obvious however, that this does not alter
the momentum of the moving power, but that, when we
would raise the water to a greater height, the machine
* yields a proportionally smaller quantity* This effect is ana-
l"oigous to that of the Seville pump.
Generalre- ^ ' ^he machine of Mr. Cagniard appears to us to include
'^'^ ' 'tnany iiew and ingenious ideas. Its application has been

guided by sound theory and a thorough knowledge of the
. true laws of physics. It appears to us, that it may be use-
ful to the arts on various occasions. We think therefore,
i. ^- . that

INStRUMENT FOR REDUCINO OR ENLARGING PLANS* IJQ

^hattheautbor merits theencpuragementofthe class, and pro-
pose, that its approbation should be given to the machine.

IV.

Description of an Instrument for facilitating the Reduction
of Plans; by Mr, de la Chabkaussiere*.

HAVE thought of an instrument for reducing plans, Simple instru-
^ ment for re-

I

which is so simple, that I am surprised it was not invented ducine"plaris.
by others long ago: bflt this simplicity, which I consider as
an advantage, is probably the reason, I call it a minudo^
meter, as its principal object is the reduction of plans;
though it will answer equally well for enlarging them.

This instrument is a wooden rule, with fiducial edges, atTheminudo-
the extremity of which is a pivot; or a plate of metal with a J"^'t,^'ji *"
hole, into which a pivot may be inserted at pleasure. This
pivot is a piece of a needle, with a knob for a head,
. On this rule are marked two scales, one smaller than the
btTier in any proportion you please. As my purpose in
making it was chiefly for plans of mines, I took as a basis a Particulailj
scale of 3 lines to a fathom, the proportion generally used pjansofminw
for such plans; and for the reduction I employed a scale of
one line to a fathom. Such a scale diminishing the length
and breadth of a plan two thirds each, all the parts will be
brought sufficiently near to be considered at one view. Such
a plan may be inferior in minuteness of detail and accu-
racy to a larger, but it has the advantage of being more
portable, and will enable the manager to have a clear idea
of the works under his direction.

Suppose then I would reducea plan of three lines to the fa- Method of
thorn to a third of this in all its dimensions. I take a rule of inmum«nt
two feet long, which appears to me the most suitable length,
and divide it into three parts, which makes eight inches, or
96 lines [of course in English measure 80 lines] to each part.
On the first division, reckoning from the pivot, I trace the
little scale of one line to a fathom, which giv« me 96.
From the extremity of the small scale I begin the divisioa

•Journal des Mines, Vol. XXVI, p. 461, Exuacted from a paper
sent to the Council of Mines.

N« of

construction.

1(8G INSTRUMEHT FOR REDUCING OR El^IiARGING PLANS.

of the larger, and the 192 Hnes*remaining give me 64 fa-
thoms each reprepented by 3^ lines*.

I afterward subdivide each of these scales by three.
»nd using it. j fi^ together the plan and the paper on which it is to be
reduced, the latter being under the small scale ; and place
the rule so that it can traverse circularly as much of the
large plan as its extent will admit. The rule being fixed on
the large plan wherever it touches a point to be transferred
to the paper, I note the number of toises on the large scale,
and opposite the same number of toises on the small scale I
make a mark with the point of a needle set in a handle, or
merely with a fine lead pencil. Thus I set down all the parts
of the plan one after another, which are found just and in
due proportion.

If the plan to be reduced exceed the length of the rule,
the instrument may be removed to another place. I need
not mention the necessary precautions in this case for
placing the minudometer properlyf.
A different At first I placed my pivot between the two scales, count-

ing the divisions in opposite directions; but as the plan was
reversed in this case, I had not the advantage of comparing
it readily with the original as I proceeded.

It is obvious, that, if we would have other divisions, we
must have different rules, or trace these divisions on paper,
and paste it on the same rule. The rule may be graduated
also on both sides J.

V.

♦ It might be supposed from the text, that Mr. de la Chabeaussicre
began to count the divisions of tlie large scale from this point; but this
would be obviously wrong: both scales must begin t.h'^ir count from the
]>ivot, consequently the first division in the larger scale must be reckoned,
in the instance before us, as SS, so that both scales will end with OG. It
should have been said too, that the pivot, or the hole for it, must be
placed in a line with the edge oi the scale carrying the divisions, C.

f Though the divisions of the scale amount to 96 toises, there are only
64 that can in reality be used. Consequently it must be necessary to shift
thfe nain udometer and the paper once at least. C. ,

•\\£ the edges were bevilled in opposite directions, and the rule were irt
two parts, made to hi into each other either way where the smaller scale
terminates ; and the units were of different lengths, though similarly di-
yided ; this would give four proportions for diminishing or enlarging. If
f9r instance the principal divisions of one of the large scales were an inch.

ON MORTAR. 'fi||

V.

On Mortars and Cements; Experiments that show (he Cohe-
sion which Lime contracts with Mineral ^ Vigetabie, or
Animal Substances; extracted from a Paper read to the
French Institute the 17 th of October, 1808, by B. G.
Sage*.

A VING found, that an alkaline lixivisl gas was evolved Gas evolyed
from a mixture of three parts of sand and two of lime slacked ^^'^^ lime and
by immersion; and desirous of ascertaining;, whether the
products of the three kingdoms, minj^led in the same pro-
portions, would afford a similar gas ; Mr. Sage made a num-
ber of experiments, which taught him, that the force of co- .- ,
hesion contracted by slacked lime was greater with metallic Metallic ox* >

oxides in eeneral, than with any other substance. These »^^* strengthen

" . / mortar,

trials led him to new facts, which enabled him to discover

mortars, or cements, at least as solid and impermeable as

those made with the best puzzolana, which is of the greatest

use, particularly in hydraulic structures.

The work we announce points out also a prompt and easy
method of ascertaining the solidity and impermeability of
mortars or ceraents, which cannot but be highly interesting
to builders.

We must not always judge of the goodness of a cement Mortar solid -
from its having acquired a great deal of coi^dity in the open '" *^^ air may.
air, for it frequently loses this in water, in which it diffuses water,
itself. Buildings made with such mortar soon tumble to pieces.

The necessity of a minute division of the substances, thajl; '^^a^/i^ ♦ ,.
enter into a cement, cannot be insisted on too strongly. Rules for mak-
They should first be mixed together uniformly while dry ; jjj^^ good mor-
and they must not be drowned in water, which must be
added gradually, till the mixture is reduced to a soft paste,

and of the other an inch and half: and those of the small scales, one half

an inch, the other a quarter j we should get the proportions of a half, , ^^

A third, a fourth, and a sixth. Two rules, with joints mutually fitting

each other, would give 16 di&erent proportions. If both edges be

graduated, there must of course be a hole for a pivot at the extremity of

each. C. '

• Journal des Mines, vol. XXVI, p. 471. The above appears to bm
the title of a pamphl«t, vrhi.h Mr. Sage has published separately.

It.

]82 <>W MORTAR.

It is of the greatest importance to determine with preci-
tion the quantity of lime employed to obtain the most solid
ptiortarti or cements; and in general to use no lime but what
has been made from pure limestone, and which has been
kept well secured from the air after it is slacked.
Two parts of In the experiments of Mr. Sage he always employed two

of"o*rhc/maf- ^^^^^9^ l''"5*^ ^^'■*^« 9^' pnzzolana, of sand, &c., which af-
ter, forded him very hard and impermeable mortar : and he thinks
this proportion of lime may even be lessened, when the
architect is fully convinced of the impropriety of leaving
the preparation of mortar to bricklayer's labourers, since the
strength and solidity of hydraulic structures depends so
much on it.
Mortar> of The author has divided his experiments into five classes,
hmt and ashes, j. Mortars or cements made with substances, that have un-
dergone the action of fire. The ashes of vegetables, whe-
ther lixiviated or not, being mixed with two thirds of lime
slacked by immersion, forms one of the most solid and im-
permeable cements: a property which they appear to derive
from the minutely divided quarts;, which these ashes contain
in the proportion of one fourth.
Lime andiron 2. Mortars or cements made with metallic substances.
oxide. Iron adds to the hardness of all mortars; and of itself, in
l"usting, copcups in the agglutination of gravel and pebbles.
Iron alone a as we see on the seashore. According to the state in which
cement. ^^^ -^.^^ j^^ ^j^^^, j^ combined with two parts of slacked lime,

its force of cohesjon is more or less considerable.
Lime anddif- 3* Mortars or cements made with jtones of different na-
ftsrent itones. tures, Gaestein, chalcedony, sandstone, and gravel, form
very hard and impermeable mortar with lime. Feldspar, bet-
ter known by the name of petuntse, being mixed with two
thirds of slacked lirue, produces an impermeable and solid.
N mortar^

4. Mortars or cements that ^Iter in water. Vesjetable
l.irne and . , , • • n i .- • i ,.

jnould. earth, or mould, is essentially composed of minutely di-

vided quartz, clay, and iron. Mixed with two parts of
slacked lime, and water enough to form a soft paste, the
brick produced from it, when dried, has some solidity,
ifbieh it loses under water, where it cracks.
X-ime an4 6» Mprtars or cpment^ oaadje with copnbustible substances.

Mortar>

ON THE METALS OF THE ALKALIS. 18^3^

Mortar, or cement, made with sulphur and two parts of combustible
slacked lime, forms a hard and very sonorous brick, which *"'*""^*^*''
is not altered under water; while mortars made with pulve-
rised vegetable charcoal, or pitcoai, though they produce '
hard and sonorous bricks, soon fall to pieces in watdr ; at
do bricks made with sawdust, or raspings of ivory.

VI.
Observations on the Alkaline Metalloids', by Mr, Bucholz*.

JL HE quantity of metalloid substance obtained varies Th<» quantity

considerably. In an experiment made lately in my appa- ^j^^^ '^^"*^

ratus with three ounces of potash, six drachms of charcoal, means of iron '

and an ounce and half of iron, I obtained but one drachm ^*^'*^*

of metalloid, divided into four or tive pieces. In the tube

were found thirty grains more of metalloid, clotty, and

contaminated with charcoal; yet all the vessels had stood

well, and remained impervious to air. The residuum, which

furnished prussiate of potash, still contafned however a

large quffiitity of charcoal. It is clear therefore, from the

small quantity of the product obtained, that it is not the

whole of the charcoal, but perhaps only the hidrogen it

contains, which concurs in the formation of the metalloid.

Not being able to determine the specific gravity of the its specific gra-

metalloid, as it alters so quickly in the air, I thought of ^'^J' *^<:'^"^^"'^'^

•1 r ^u J -^ • 1 • 1 • II bv a mixture

composing an oil ot the same density, m which it would of i^rd and oil '

neither sink to the bottom, nor float on the surface, and of petroleum,
which consequently would be of the same specific gravity.
This I did by mixing oil of petroleum and lard. The spe-
cific gravity of this mixture was 0*876.

Twenty-five grains of the metalloid, converted into pot- Metalloid con-
ash by water, and saturated with muriatic acid, produced verted into pot-
45 grains of fused muriate of potash, which, according to fn wTiri^t*(^2. '
Rose's analysis, would contain 30 grains of potash and 15
of acid : but, as only 25 grains of the metalloid were em-

• Ann. it Chimie, -vol. LXXIII, p. 7S. Translated from Gehlen*#
Journal for May, 1808, by Mr. Tassaext.

ployed)

. ployed, there was an increase of O*:?, which favours. the opi-
nion of the alkalis being metallic oxides; otherwit^e we must
suppose, that this increase of weight arises solely from the
water of crystallization.
Its combustion luto a well closed bottle, containing four ounces of lime-
rendei^ed Itme- ^g|.gf ^ above half a grain of the metalloid in several glo-
owing proba- bules was introduced. The combustion was effected very
b'y to carbon speedily, and the water was rendered very turbid every time
hexineoil. * the globules sunk down, as Curaudau had observed. It
might be presumed therefore, that the metalloid contained
carbon ; but, as it is very difficult to separate all the ad-^
bering oil, it may still be supposed, that the carbonic acid
The eombus- came from this oil. I thought I should obtain a much
tion of Its more certain result, by converting the metalloid into an
amalgam did -^ i *• • • -4. • r

uot. amalgam with mercury, and thus immersing it in lime-y

water, which jyould prevent the combqsiipn of the pil. In
this process the evolution of gas was very brifli, without the
water becoming turbid ; but the gas gradually ceased to be
evolved, and the surface of th.e amalgam became covered
with a light gray pellicle, which rendered the flujd turbid
and gray, but not milkj^ A few drops of nitric acid did
not make this cloudiness disappear, and the ipixture ac-
quired a metallic taste. I poured distilled water Qn the re-
maining amalgam, and the evolution of gas commenced
ainew with a great deal of energy;^ but no pellicle was
formed, and the liquid did not become turbid. Thjs result
jnay be explained or) the supposition, that the contact of
limew^ter favours in some degree the oxidation of the mer-^
cury ; though it is not easy to say why this should take
place, as it does not with dirftjlled water, and accordingly no
pellicle i& formed. As no trace of carbonate of lime ap^
pears, it may be concluded, that the metalloid contains no
carbon ; but it \yould be well to confirm this by fresh exp^«
rimenls,
Amalgam dif. On triturating one part of metalloid of potash with thirty
irthe *^proiK)r- ^'^ mercury in a porcelain mortar, a pretty ductile amal-
tjon of mer- gam was formed, resembling amalgam of tin : but with ten
*"^>> or twenty parts of niercury a gray pulverulent substance

only was obtained, which assumed a metallic brilliancy by
pressure. On continuing to bray this substance, it became

moist.

ON THE METALS OF THE ALKALIS. 2g^

tnoist, formeH at length an alkaline liquid, and the mercury

beta tne fluid. The te«denry of this amalgam to coin bi ne & has & strong

with other metals is surprising, it combines even with iron o^e^ me[ 1

at the instant of contact, and extends on its surface; but

after some time the metalloid returns to the state of potash,

and the mercury j^epurates from the iron.

Twenty-five grains of the metalloid of potash being heatr Potas«5ium

cd red hot in a nurrow-moulhid vessel, 4he small globules ^^'*^^** ^^^ ^^^

' ; " Ui a narrow

united into larger, which l^ad a bright metallic lustre, that mouthed Tes-

wa« a mean between that of tin ami that of silver, and were ^^^>

very iluid. On cooling they assumed the appearance of a

hard amalgam of tin. In the open air they became covered and afterward

at first with a gray coat, which became blue in a greater *'*'^^'^^^*^.*^*

r^ J ' » action of air,

heat, and the blue colour of which grew much deeper,

when the gray pellicle was removed from the melted matter.
On heating it more strongly all the colour disappeared, and and of heat.
the uhole assufned a silver whiteness, with a metallic lustre,
which became gray on cooling. A little of the fused mat-
ter, being brought into contact with the air, took fire, and
gave out a white vapour, not alkaline, which deserves exa-
mination. On heating it to a cherr}' red, a liquid matter
was produced of a yellow brown colour, and destitute of
metallic lustre, which gradually became of a blue green,
and comported itself as a siliceous compound that attracted
moisture from the air. Potash therefore was formed with-
out previous inflammation, and the metalloid of potash had
attacked the glass, agreeably to the experiments of Mr.
Davy.

Some time ago I treated alkaline matter, from which I potassium oIj-
had failed to obtain metalloid, with linseed oil, according ta'"e<J by
to Curaudau s process*. Havuig subjected it to a very vio- .^qq^ qji,
lent heat, I could obtain no fluid metalloid in the receiver;
but in the necl> of the retort 1 found a portion in clots,
mixed with carbonaceous matter, weighing about two
drachms. On heating it, and straining it through a rag
under heated petroleum, 1 obtained half a drachm of liquid
metalloid.

The residuijim still comported itself like the pure metal*

^ See Jottrnal, vo\. XXIV, p. 38 •

loid

14J6 OS TtlE METALS OF THE ALKALIS.

A detonating loid with water, mercury, and other substances. The coally

pyrophoroui Q^atter, from which the metalloid had been sep;irated, ap-
coal produced. . , .

pcared to me a detonatiii^ pyrophoric product ota pecuhar

Ifs properties, nature. It had the following properties. Its colour varied
from deep bhick to brdwnish black, and black blue. It had
a greater or less degree of cohesion, a pulverulent consist-
ency, but requiring the stroke of a pestle to reduce it to
powder. The pulverulent part inflamed with noise on the
contact of air; but the large pieces did not take fire, till
they had remained exposed to the air some time. They in-
flame more quickly when moisture is near. On triturating,
striking, or pounding this matter with a solid body, it de-
tonates with more or less noise, with flame, and with dis-
persion of the matter when the pieces are large. The noise
resembled loud cracks of a whip. 1 have even observed,
that this deconi position of the metalloid with noise takes
place sometimes under water, and occasions a violent com-
T>an(;erous ac- motion in it. This detonating product was near occasioning
cidems. nie as disastrous an accident, as the metalloid did Mr. Gay-

Lussac; for, in attempting to get all the matter out of the
neck of the retort with a sharp-pointed iron wire, a portion
detonated with a great deal of noise, and almost all the
burning matter flew by my face. It is obvious therefore,
^'f. that we cannot be too cautious in operating on this sub-
stance *.
Action oi' pot- On another occasion 1 observed a very violent action from
as5hjmon ojl ^qj^^ coally matter tilled with metalloid, I poured about
•f turpeiituie. , , • p .-c i i x- ^ ..- i

a drachm into an ounce oi rectitied oil ot turpentine, and

immediately perceived a very strong ebullition of the oil,
part of which was volatilized in smoke. What remained had
almost entirely lost its smell, but had acquired a striking
smell of solution of camphor in oil of turpentine, yet I
could not by any means discover the presence of camphor.

Detonating * ^ »nJxturc of sulphate of potaslj and vegetable charcoal, in a large

mixture. proportion, produces a Similar effect. Collet' Descotils.

\lh

ON oxiMtJRtATifc Acid, I37

VII.

Farther Observations and Experiments on Oximuriatic Acid,
by J. Murray, Lec^itrer or^ Chemistry, Edinburgh,

To Mr. NICHOLSON.
SIR,

N a former communication I had given an account of
some experiments, which I regarded as subversive of Mr.
Davy's lately proposed hypothesis on the nature of muriatic
and oximuiiatic acids. Of these some of the results were Result of the
called in question by that gentleman, particularly that in^^^o^ofc^rr
which carbonic oxide, hidrogen, and oximuriatic acid gasses hidrogen, and
were subjected to mutual action, either at a low tempera- ox>raunauc
ture or by detonation. The production of carbonic acid in ed.
this experiment he appeared to have considered as arising
from the operation of the water introduced with the view of
examining the product; he employed therefore dry ammo-
niacul gas, and with this variation he stated, that there is
no conversion of carbonic oxide into carbonic acid. Though
satisfied, that there is little probability in the supposition of
any fallacy from this source, 1 thought it right to repeat
the experinnent so as to exclude its operation, and having
lately done so, I beg leave to communicate the result.

1 may previously remark, that I had objected to the im- ^f^ Davj's ex-
perfect manner in which Mr. Davy's experiment was exe- periments on
cuted ; ho attempt apparently having been made to discover
-if carbonic acid were formed, but its nonformation having
been inferred merely from the residual gas burning with
the bame coloured flame as carbonic oxide. This has since
been attended to, and the experiment performed with a
more strict txiamination of the result. An account is given
by Mr. J. Davy in his last communication of this repetition
of the experiment. A mixture of 10 measures of carbonic
oxide, 4 measures of hidrogen, and 14*6 measures of oxi*
muriatic acid gas contaminated with 2 of common air, was
inflamed by the electric spark ; the residual air being deto-
nated with oxigen was found to contain 8 measures only of
carbonic oxide ; 2 measures of this gas therefore had dis-
appeared.

iS& ON OXiMURIATIC ACID. ^'

appeared, and it appears to be admitted in the stntement of
the experiment had been converted into carbonic acid, as
indeed no other conclusion could be drawn. But this is
ascribed to the action of tlie common air, or oF moisture iii
the gas8fes> an«^ it isf inferred, that, when the action of these
is taken into account, " no result more satisfactorily cou-
" elusive that no carbonic acid was formed could be ex-
" pected."
pfoducei} car- It is at least established, that in this experiment, when
baaicaeid, ^j^^ results are submitted to accurate examination (even
with the precaution, which Mr. Duvy deems so essential, oi
substituting ammonia for water), there is a conversion oi
carbonic oxide into carbonic acid. The Jact therefore is
admitted, which I had asserted, and which had been before
noi sat'tffacto- denied. The sitppodtions by which it is now attempted to
V^ aecttuwted |^ accounted for I regard as unsatisfactory, no proof being
given, either that the causes assumed did operate, or were
adequate to the production of the eifeet. With regard to
the supposed operation of the atmospheric -air mingled with
the oximuviatic gas, it is not probable* that, diluted a& it
must be by the large intermixture of elastic fluid, its oxi-
gen would combine with the carbonic oxide in the feeble
inSamraation, which from the small portion of hidrogen
employed would take place in the experiment. And even
if it had combined, the quantity of it was not sufficient to
JliavQ converted into carbonic acid half the quantity of car-
bonic oxide which disappeared. With regard to the sup"
pcsed effect from moisture, as the carbonic oxide and hidro-
gen gasses were previously dried, it can scarcely be assumed
to have been present to the extent which it is necessary to.
suppose, allowing even that it could operate in the mo-
ni€ntary action from the detonation. And i^ there were
grounds for supposing, that these circumstances were of
any importance in producing the result, why were they al-
lowed to operate h It ia easy to obtain oximuriatic gas witb-
ftut BUih an intermixture of common air as 2 measures in
J4; it can also be dried by submitting it to the action of
substances which abstrnct water. When they could thua
Kave been excluded, the only reason that could justify this
aduttisiioo was the belief, that their influence was so unim-
'' portant

ON OXIMURtATtC ACID. 1S9

portant that it might be disregarded. But to admit them,
and at the same time to assume that their operation had
given rise to the result, the possibility of obtaining which , M

independent of snch circumstances is the very question at '"• ^

issue, appears to be making by choice an ambiguous in-*
stead of a decisive experiment. I am satisfied however,
that these circumstances had no important effect. And
when we have the actual formation of carbonic acid, and
only such modes of accounting for it to avoid the con-
clusion, that oxigen is communicated from oximuriatic acid,
I cannot but regard the result as being in conformity with
that which I have always stated to be obtained.

One other observation with regard to this experiment I The proporiioti

tind it necessary to make. In employing hidrogen gas to ^5 ^'^^^*" J?

. . .\ i_ • • 1 them too imaiU

promote the action of oximuriatic acid on carbonic oxide,

the proportion I used was equal volumes of the hidrogen
and carbonic oxide, and in the repetition of the experiment
with the view of ascertaining if the result I had stated were
accurate it was to be expected, that the same proportion
would have been observed. IMr. Davy in his former expe-
riment used the proportion of 8 parts of hidrogen to (0 of
carbonic oxide, a deviation of no great importance, and of
which therefore I did not think it necessary to take notice.
But he has now employed the proportion of only 4 mea-
sures of hidrogen to 10 of carbonic oxide. I know not what
may have been the reason for this change of proportion,
but it is obvious what effect is to be expected from it. I
had found, that dry carbonic oxide gas, and oximuriatic
acid gas, do not act on each other; and I had affirmed, that
they do act, and that there is a production of carbonic acid,
when a portion of hidrogen is added. According to the view
with which that hidrogen was added, that of affording a
certain portion of water necessary to the constitution of
muriatic acid gas, the larger the quantity used, the con-
version of carbonic oxide into carbonic acid by the oximu-
riatic acid might be expected to be more complete. IVIr,
Davy r«»peats the experiment with the view of disproving
the result I had affirmed to be obtained ; but he reduces the
proportion of hidrogen more than one half; and from not
attending to the effect of it^ betvithdraws as far as possible

the

IQQ ON OXIMURIATIC ACIB.

the very circumstance held to be essential to its success. Andl
still with this variation part of the carbonic oxide is con-
verted into carbonic acid,
TFarther expc- 1 have now to state the results of the experiments I have

limentssub- performed, substitutinj' ammonia for water, in examining

sntutmg am- \ . . ^ , ,

monia for wa- the product of the n^utual action of the gasses. 1 was as-

**^^* sisted as before in making these experiments by my friend

Mr, Ellis, and the results were witnessed by some other
friends.

Cxp. 1. Ten measures of carbonic oxide gas, and 10 measures of

hidrogen gas, each of which had been previously dried by
exposure to lime, and ^20 measures of oximuriatic acid gas,
obtained from a mixture of muriate of soda, black oxide of
manganese, and diluted sulphuric acid, and which had
been kept in contact with muriate of lime, were mixed to-
j^ether in an apparatus fitted with stopcocks, so that the
gasses could be transferred and mingled without the inter-
vention of water or of quicksilver. The mixture was ex-
posed to light, excluding the direct action of the solar rays,
for about 36 hours. At the end of that time, the apparatus
being opened under dry quicksilver, a small quantity only
entered, indicating a very inconsiderable diminution of vo-
lume; and the quicksilver acquired a slight tarnish, a proof
of the presence of a small portion of oximuriatic acid. The
gas was transferred through dry quicksilver into an inverted
jar'; and ammoniacal gas, which had been previously dried

Carbonic wild by exposure to lime, was added to it. Dense white vapours

apparency v/e.re abundantly produced, and the introduction of the am-
prodttced, . i p • , , ■

monia was renewed irom time to time, until their produc-
tion had ceased. A little water was then introduced to ab-
sorb the excess of ammonia, and dissolve the concrete salt
that had condensed. The solution was rendered turbid by.
the test of muriate of barytes, indicating the production of
carbonic acid*.

I soon

Presence of ♦ In hoine experiments this result -was not obtained, or the traaspa<

carbonic acid rency of the solution was at least little impaired. To discover the cause
not always im- ^^ ^j^j^ j ^^^ dissolved small portionsof muriate and carbonate of ammo-
medrately per- , .,..., , , . , ,

ceptib!e, "'* '" water, thus preparing a solution similar to that which I suppo'-.ed

to be formed in the experiment j but on adding to it muriate ef barytes

there

ON OXIMURIATfC ACID. 191

I sooD ascertained this in a manner aUog^ether unequivo- Formation of
.mi 1 I 1 1 -J !• L • carbonic acid

cau 1 he concrete salt, condensed on the sides ot the jar pjovetl.

when the action of the ammonia had ceased, being collected, ^

on dropping it into dilute muriatic acid, a sensible cfFer- .^

vescence was observed, especially when it had been taken
from the upper part of the inverted jar. This latter circum-
stance appeared to indicate, that the ammonical gas, when
introduced to the elastic fluid remaining after the mutual
action of the three gasses, had combined first with tlie muri-
atic acid, and afterward more slowly with the carbonic acid
that had been formed, so that the product of this latter com-
bination had been deposited principally towards the head of
the jar; a result which might indeed be expected from the
more powerful action of muriatic acid, than of carbonic acid,
on ammonia. This afforded a mode of obtaining the two pro-
ducts in a great measure separate. On adding the first portion Exp. t»
ofammonia,the white vapours were allowed to condense, the
rei-idual gas was transferred into another jar, and a fresh
portion of ammonia added. The salt obtained from the
sides of the first jar was principally muriate of ammonia,
that from the second was carbonate, and when dropped on a
dilute acid effervesced as strongly as pure carbonate of am-
monia did. The production of carbonic acid was esta-
blished therefore beyond the possibility of doubt : it farther
appears, that the conclusion 1 had drawn from my former
experiments was correct, and that there is uo fallacy in the
introduction of water after the mutual action of the gasses
to examine the product, the result being equally decisive
when anip:ionia is employed.

The residual gas in these experiments was found to be a Residual gas.
mixture of hydrogen and carbonic oxide, with a little ni-

thcre was no precipitation ; and I farther found, that the transpareDCy
of a solution of pure carbonate of ammonia is not immediately im-
paired by thia teat. This may be ascribed partly perhaps to the action of
ammonia counteracting the formation of carbonate of barytas, but
principally to the excess of carbonic acid in the carbonate of ammo-
nia, which contributes to retain the barytes dissolved. Hence sub-
carbonate of ammonia gives a precipitate with muriate of barytes,
and iu the above experiment the solution became turbid on the addi-
tion of the mnriate only when an excess of ammonia had been added to
the elastic fluid formed by the mut«al action of the passes.

troffen

192 OK ©xiMuturrc acid.

tfogen arisiriw from the action of the oxi muriatic acidf on
the ammonia. When mixed with atmospheric air and
kindled, it burned not with the blue lambent flame of car-
bonic oxide, but with the quick flame of hidrogen, and af-
forded by its combustion only a small quantity of carbonic
acid. This residue of inflammable gas, while there also re-
mained a small excess of oximuriatic acid, is probably to be
ascribed to imperfect exposure to light.

The slow ac- jjj performing these experiments I preferred the method
tion pteferablc „ / . . *! ^ , ' , .. . .

to detonation **' submittmg the gasses to slow mutual action at natural

temperatures to that of promoting it by detonation, both as
capable of being conducted with more accuracy, and in
itself more conclusive. In the mode by detonation it is
necessary to operate over quicksilver, and from the action
of the oximuriatic acid on the quicksilver it is more difficult
to ob^serve the phenomena of the experiment, and to esti-
mate the results. In the slow action this may be avoided.
"^ We farther avoid any fallacy which may be supposed to

arise from the high temperature in favouring the decompo-
sition of any water that may be present. And the mutual
action, from its continuance, appears to be more complete,
I confirmed however the preceding results to a certain ex-
butthe latter tent, by performing the experiment by detonation, the test
results. ^^ muriate of barytes indicating the presence of carbonic

acid in the solution formed by the introduction of water after
the ammonia.
Experiments Mr. J. Davy in his first reply to my observations on this
shank "*^ ' subject stated, that he had repeated some of Cruickshank's
experiments on the production of carbonic acid by the action
of oximuriatic acid on the carburetled hidrogen gasse?.
When the experiment is made over water, some ambiguity
may be supposed to arise from its influence. But even
when it is excluded, a portion of carboni« acid ought to be
formed from the agency of the hidrogen similar, to that in
the preceding experiments: and I did not make the expe-
riment to ascertain this only from the uncertainty with re-
gard to the existence of oxigen in the composition of these
gasses, which, if carbonic acid were formed, it might be con-
repeated by tended contributed to its formation. Mr. J. Davy however
Mr. Davy. considering this source of fallacy as of little importance, per-
formed

Oir OXIMUEIATIO ACID. 193

foroied die experiment, excluding water, and stated, that Mr. t>aT^.
he "never obtained carbonie acid gas, though oximuriatic
gas in great excess was employed.'* I alluded briefiy in
my reply to the source of errour whence this observation I
conceived had arisen, and I now find my conjecture to have
been just. I had found in the case of the production of car- ^^^^^ *^
bonic apid from the mutual action of oximuriatic acid,
hidrogen, and carbonic oxide, that no milkiness is apparent
on the first or even the second transmission of the gas
.through lime water, the small portion of remaining muriatic
^r Oxipiuriatic acid preventing the formation of carbonate of
lime, I had no doubt that this had operated in Mr. Davy*s
experiment, especially as he laid stress on the very cir-
cumstance which would give rise to it, the great excess of
oximuriatic acid employed ; and I have found, that this is
the case. One measure of carbu retted hidrogen gas ob-
tained by passing watery vapour over ignited charcoal, freed The expeti-
from any intermixture of carbonic acid by careful agitation ^*2^'^*"
with lime water, and afterward dried, was mixed with a
mejjsure and a half of oximuriatic acid gas passed over dry
muriate of liipe; the mixture was inflamed over dry quick-
silver by the electric spark ; the residual gas was transmitted
fir^t through water, and afterward through lime water; no
milkintss was apparent in the latter on the first or second and carbonic
transmission, but on the third the surface became milky, ^'^^^ produced,
the whole became turbid on agitation, and this was repeated
on two or three subsequent transmissions. The production
of carbonic acid was therefore not in the least doubtful*.

* The rcsjdual f^a^ in this cxperimcat burned vith the Hue lambent Residual gas.
flame of carbonic oxide, and gave carbonic acid in its combustion. If
it were found to be cai1)onic oxide, it would prore, on tbe sup^ositipn
that tbe gas from humid cbarcoal after careful washing with water is
a binary compound of carbon and hidrogen, that still more oxigen had
l^ecn commuoicated from the oximuriatic acid, than had gone to the
formation of the icarboBic acid ; or, if this were not admitted, the re-
sujt would throw some light on the dipputed qnpstioft with regard to
what arc named the carbuiipUed hidrogen gasses, whether ozigen ex-
ists in their composition j as it would i-ender probable the opinion,
that this gas at least is a ternary compound of ©irbon, hidrogen, and
oxigen, in opposition to the opinion, that it hi a binary Compound of
carbon and hidrogen. ^

Vol. XXIX.—Jult> 1811. O . Th«

OK OXIMCRliTIC ACID.

The results of all these experimentg then, instead of in*

The sources

All the results

former state- Validating, confirm what I have before stated,
menu of fallacy supposed to exist have been found to have no

effect ; and the more accurately the results have been exia-
mined, the more strict has been the coincidence with that
statement. In all of them carbonic acid has been found to
be formed, and Messrs. Dav)»8 appeared not to have ob-
tained it in their experiments, because they did not look for
it with sufficient care, or were not sufficiently aware of the
fallacies, by which its production might be concealed.

On the other topics of this discussion I am pleased to
find, that it is not necessary for me to enlarge; as, with
regard to those of any importance, Mr. J, Davy has in his
last communication either attempted no reply to my observa-
tions on his former statements, or the reply is in general such,
that, with a few remarks, I willingly leave the decision to the
judgment of those, who have given attention to the ques-
tion.
Remark on He still for example professes to maintain, that the pro-

that^Sr^^"' position "muriatic acid gas is a compound of oximuriatic
Davy's state- acid and hidrogen" is not an inference from the fact, that
this gas is obtained from the mutual action of these two sub-
stances, but is the expression of the fact itself; that because
they are the only substances concerned in the experiment,
and it is equal in weight to the weight of them employed,
" muriatic acid gas is not inferred, but immediately per-
ceived to be a compound of oximuriatic gas and hidrogen,
and that all the other cases are analogous.'* His brother's
views therefore he contends are not hypothetical ; and, if I
fail in proving them such, I fail, he adds, altogether. I
confess I have felt surprised, that this ground of defeace
ever has been assumed, and that Mr. H. Davy should have
remarked, that I have mistaken his views in supposing them
to be hypothetical, adding, that "he merely stated what he
had seen, and what he had found.'* And although Mr. J.
Davy might at first have adopted these sentiments, I had
hoped, that the observations in my former paper would
have convinced him, that this view was a hasty one, that
these pretensions were too high, and that the subject might
be presented under a very different aspect. If I have failed

in

ment is not
hypothetical

ON OXIMURIATIC ACID. 195

in this, I must despair of being more successful by any Remark on
farther illustrations, and I feel indeed no desire to add illus- ^^^j^^ ^^ '^ »
trations on what appears to me too obvioui to bear a mo- D«vy's state,
ment's reasoning. I shall only present the subject under hypotheiicall
one other light ; and beg to remind him, that the very pos-
sibility of the proposition being called in question without
any doubt being expressed of the accuracy of the experiment
on which it rests is a sufficient proof, that it is not a simple
exprt^ssion of the fact, as he and his brother suppose, but an
inference from the fact, I should not involve myself in the
absurdity, or rather in the palpable contradiction of deny«i|||
ing, that muriatic acid gas is obtained from the mutual" -^
action of oximuriatic acid and hidrogen, and is the only ^
sensible product of that action, while I did not call in ques«
tion the accuracy of the experiment of which this is stated to
be the result ; though t feel no hesitation in denying (equally
admitting the experiment) that muriatic acid is a com-
pound of oximuriatic acid and hidrogen. I perceive an es- '
sential difference between these two propositions; the one
(supposing the experiment accurate) is a simple expression
of a fact ; it will for ever remain true, be the progress of the
science what it may, and no one who understands the terms
in which it is expressed will call it in question ; the other is
an inference from the fact, which may be questioned, and
may prove to be false. If Mr. Davy however can perceive
no difference between them, he is right in maintaining, that
his brother's opinion is a genuine theory. I trust I need not
add, to avoid misconception, that I have admitted, that,
were our iuduction to be restricted to this fact, the conclu-
sion drawn by Mr. Davy, as it is the most direct, would be
the most probable one; it is only when connected with the
other phenomena to which it is related, that it becomes
more doubtful ; it then comes in contact with a different
conclusion, which may be drawn, and which in relation to
some of these phenomena has in its turn the advantage of
being more directly inferred ; the two are to be compared
in their whole extent, and the one which in its application to
all the phenomena shall appear most probable is to be pre-
ferred. It is altogether a limited view, to look only to the
experiment of the production of muriatic acid gas from the

Q 3 mutual

Ig6 ON OXIMURIATXC ACID.

mutual hction of djiiuiuriatie acid and hidrogcn ; for, to
draw the concluwon from thnt experiment, \ve must, previ-
ously know what is the constftutioti of muriatic ncid «;as,
and what the constitution of oximuriaticacid ; and the roost
probable inferences with regard to these must reguUite the
conclusion that ought to be drawn. If there is reason to
"tj't^lieve, that the former is the real acid, and tliat the latter
IS a simple substance, it may be inferred, that muriatic
acid gas is a compound of oximnriatic acid and hidrogen.
But if there are facts whence it can beinferred, that muriatic
, Ipa^id gas contains water, or that oximuriatic acid contains
-^ Qxigen, the theory of the experiment must be given in con-
formity to these — the oxigeh 5f the oximuriatic acid com-
fciilng with the hydrbgeti, and forming water, which the
muriatic acid holds combined with it in the elastic form.
Thfre are facts from which these are the most direct and
j)ro5ai/<? conclusions; and these conclusions are avoided by
less direct, and more complicated and hypothetical assump-
tions. And it is merely an errour in logical deduction to
suppose, that such assumptions require no independent
proof, but are established because they would follow if the
^inference were admitted, that muriatic acid is a compound
of oximuriatic acid and hidrogen.
Most obvious To somfi of the examples which I had given, illustrating
conclusjon nof^l^^ senerai'proposition, that the most obvious .conclusion

always just. ^ .

^from an experiment is not slvvays the just one, Mr. J. Davy

'has stated some objections, which perhaps it is superfluous

*to notice; for, were even the illustrations incorrect, the

proposition itself cannot be denied, and it might be easily

'illustrated by other examples, Ihe truth however is, that

the exaniples I have given remain in full force. To one of

^lhe"m indeed, that from the production of dry muriate of

. " potash, no objection has been offered. With regard to the

i»toduction of , other, that of the production of calomel by combining mu*

calomel. .^^ * riafic acid'and oxide of mercury, there may be, as he sup-

•'poses, aprOrluction also of water, (though this remains to be

' prove<^) yet still the most direct inference from the experi-

'mentls, that calomel is a compound of the oxide and acid ;

' 'to»^ itis a mprc simple conclusion, that this water had been

''d'ebc's»te*(l'^?om fJie acid, than that it had been formed *by

^ *• - the

the oxigen of the oxide combining with bidrogen from the

acid, while the oxiouriatic acid rombiues with the metallic

mercury to form the i'aioip.elr Mr* jDuvy seems to dpu^t

indeed if calomel can be formed by presenting mviriatic

acid to oxide of mercury. If the metal is highly oxidated,

corrosive sublimate, it has long been known, is fo^med; but

it is equally true, that cuiomel is the product of the mutual »

action of muriatic acid and mercury in a low state of oxi« * A,

dation.

I bad given as an example of hypothetical assumption in Production of
Mr. Davy's system, the explanation of the production of <*^.'"'wiatic
oxiniuriatic acid by distilling muriatic acid from oxide ^^ tliiUc dc'id ^nk
manganese; the explanation £Mppo«i»g-, that the oxigen of "X'^^e ©f man-
the oxide combines with the hydrogen of the acid and/orw* ^*"*'*®'
water, while the oxi muriatic acid is set free. To this Mr. /
J. Davy replies : ** Mr. M. asserts, that Mr. Davy is ob^
liged to suppose, that water is produced in the common
mode of making oximuriatic gas from muriatic acid by
means of the black oxide of manganese. Mr. Davy has as-
certained the/ac^ that oximuriatic gas and water are pro*
duced, when black oxide of manganese is heated in muriatic
acid gas." It is almost superfluous to remark, that here the

i leading term in the proposition, and on which the whole dis-
cussion rests, is changed. 1 had asserted, that Mr. Davy

'is obliged tosuppose, thatin this experiment \s2Xer\s formed'.

.and the assertion is strictly correct. To say, that Mr.

' Davy has ascertained the fact, that water is produced, is
saying nothing to the point. TheprorfMc^ioji of water in an
experiment is not its ybr/no/ion, nor is it a proof of it ; it is
as probable a priori, that it is deposited, as that it is
formed : unless there be particular evidence indeed for the
latter conclusion, the former is to be preferred as more sim-
ple and direct; and though water is produced, in other
words becomes sensible, when muriatic acid gas acts on
black oxide of manganese, I repeat, that Mr. Davy
is obliged to suppose it is formed ; and that he has no other
proof of its formation than the supposed truth of his hypo-
thesis, which is of course assuming the point in dispute.

In a different part of his reply Mr. J. Davy, from not at- t^- .• .•
tendmg to this dwtmction between the production of water beiwe«o pro*

and

Jgg ON OXIMURIATIC ACID« ,

auctionand and the formation of water, has supposed, that I have ne«
formation. , , - , , .

glecteci Its agency in an experiment, when 1 only suppose

the most direct conclusion, and the one nipst strictly ana-
logous to that which would be formed in similar cases, to be
drawn. If muriatic acid gas in acting on a metallic oxide
disappears, forming a solid product, while water is also pro-
ik duced, the most obvious and direct conclusion, and the one
t ' most conformable to a very extensive analogy is, that the

acid has combined with the oxide, and that the water had
been previously combined with the acid, but does not enter
into the new combination. If nitric acid vapour, or sulphu*
ric acid vapour, were transmitted over a metallic oxide, with
similar results ; the disappearance of the acid, the formation
of a solid product, and the production of water; this is the
* very conclusion which I suppose Mr. J. Davy would consi-

der as the legitimate one; and it may he well for him to
consider a little further the grounds on which he violates
this mode of induction, in refusing to draw a similar con-
clusion with regard to muriatic acid.
Hypothetical I ^'^^ given some examples pf hypothetical explanations
explaaaticns j^ Mr. Davy's system, which I regarded as much more
system. *^^ " complicated than any of those which are given in the oppo-
site opinion. Mr. J. Davy has endeavoured to render them
more simple, but I fear with little success. Dry muriate of
potash is regarded as a compound of oxi muriatic acid and
potassium. On dissolving it in water, I conceived, that,
in conformity to the system, it was supposed to be converted
into a compound of muriatic acid.jind potash, a portion of
the water being decomposed, its oxigen communicated to
the potassium, and its hidrogen to the oximuriatic acid:
antrl that again in expelling the water from this solution,
and obtaining the dry salt, the hidiogen of the acid and the
oxigen of the potash combine, forming w£(ter, while the oxi-
muriatic acid and the potassium enter into union. In
giving these as the explanations which are conformable to
Mr. Davy's system, I believe I have done it justice; and
that, though sufficiently hypothetical and complicated,
they are the most probable of which it admits, and are in
conformity to his own statements : "the action of water on
these compounds which have been usually considered as

muriates.

/

ON OXIMURIATIC ACID. 299

muriates, or as dry muriates, but which are properly combi-
nations of oximuriatic acid with inflammable bases," being
stated to be exactly that which 1 have described ; oxigen
being supposed to be communicated to the base, and hi-
drogen to the oximuriatic acid. Mr* J. Davy rightly re-
marks, that they are conjectures: and to avoid them, he sa-
tisfies himself with remarking, that "fused muriate of pot-
ash is a compound of oximuriatic acid and potassium; atid
the solution of muriate of potash is a compound of oximu-
riatic acid, potassium, o sigen, and hidrogen." If fused
muriate of potash is a compound of oximuriatic acid and
potassium, liow can it be obtained from the watery solution
formed by uniting potash and muriatic acid, by the. evapo-
ration of the water, without the very changes taking place,
which I have stated ? With regard to the changes that oc-
cur on dissolving it in water, Mr, Davy gives a view indeed
somewhat ditferent from that which I had stated, but not *
much to the advantage of his hypothesis. It is not merely
it seems a portion of water that is decomposed so as to form
muriatic acid and potash ; but the whole water, if the above
statement of Mr. Davy with regard to the nature of this
solution have any distinct meaning, is decomposed ; and the
solutionis a quaternary compound of potassium, oximuriatic
acid, oxigen, and hidrogen, in which neither potash, muri-
atic acid, nor water exists. If this is simplifying chemical
theory, and rendering it more probable, we have hitherto
been much mistaken in our notions of simplicity and pro-
bability. I know not if Mr. J. Davy is prepared to extend
the same view to other analogous cases, and to say for ex-
ample, that, when we dissolve sulphate of soda in water, we jjj^ a\^*^
form a compound of sodium, sulphur, oxigen. and hidro- '.» *;CI

gen. It is needless to analyse the other example of the
mutual action of nitrate of mercury and muriate of «oda,
as the same remarks nearly apply to it.

I had stated the fact of charcoal not being acted on by Nonaction of
oximuriatic acid as presenting an anomaly in Mr. Davy's advUm'char-
hypothesis; for, since oximuriatic gas is held to be a prin- coal,
ciple similar to oxigen in its general chemical agencies, it
ought like oxigen to combine with charcoal, and still more
w, since it combines with all other inflammable and me-

talUc

nr

200 ^^ OXIMCJRIATIC ACID.

tallic substances. Of this a satisfactory e!>(pIaQBtiop moy
be gVveii in conformity to the opinion, that oximuriutic
acid acts on inflammables by imparting exigen ; while
it r^main« aii anomaly in the opposite opinioii. To
this the rep^y i* made by Mi*. J. Davy, that 1 seem lb
consider eVery thin^ anomalous, that is not accounted
for; and the query i§ added, "Can Mr. M. account
for the Want of action bt^tween charcoal and nitrogen,
and between the metals and nitrogen ? and, if he cannot,
(Soes he consequently consider these facts anomalous?"
The fallacy of this reasoning I should scarcely have sup-
posed could have escaped observation. The anomaly with
regard to charcoal is not simply, that it is not acted on by
oximuriatic acid, as it is not acted on by nitrogen; but that,
beir>g an inflammable substance, and evjry other inflam-
TAable being acted on by oxi muriatic acid, it is not. In-
flammable substance are not acted on by nitrogen, we
have therefore no reason to expect any action to be exerted
by it on charcoal ; while there is reason to expect, that
charcoal, in common with other inflammable substances,
should be acted on by oximuriatic acid ; in the one case
there is no general result, to which an exception occurs ; in
the other there is, and there is therefore an anomaly. Of
this singularity with regard to charcoal, the explanation
which may be given in conformity to the common opinion
is so satisfactory, as to afford even a presumptive proof of
the truth of that opinion, the fact being precisely what
might be expected to occur. On Mr, Davy's hypothesis it
is confessedly incapable of being accounted for.

Kewga«;ob- With regard to the new gas, which Mr. Davy has ob-

served by Mr. J J , J *!. r • -A- -J

Davy. aervedy a compound, as he regards it, or oximuriatic acid

and oxigen, I have little to «ay. Without speaking lightly
of it, as Mr. J. Davy imagines; or without doubting, that
it may be able to convert carbonic oxide into carbonic acid ;
I may siroply remark, that I have no reason to believe, that
it operated in my tirst experiments; it no doubt was ex-
cluded in the repetition of the experiment by Mr. H. Davy,
in which, as has already been remarked, carbonic acid is
formed ; and I have farther avoided it in the experiments
stated fii this communicaftion, without finding ftny differ*

ON OXIMURIATIC ACID. 201

ence in the results. The difficulties which Mr. Davy hat
supposed attend the common opinion from the comparative
inactivity of this gas, though it contains more oxigen than
oximuriati'c acid, and which he imagines will probably lead
me to "adopt the new idea, that oximuriatic ^as is a sim-
ple body," appear to me of no weight., The powerful ac-
tion of oximuriatic acid does not depend merely on thti
ijuaHtity of oxigen it contains, but on the t.tute of oombina-
nation of that element, and the dispoHug affinity exerted
by the muriatic acid; and I can easily suppose the quan*
tity of oxigen to be increased without any augmentation, or
even with a diminution of power. It will be time enough
however to explain this to Mr. J. Davy, when the proper-
ties and composition of this new compound are more fully
detailed.

1 have now given all the attention to this controversy,
which it appears to me to claim ; and the progress of it has,
1 trust, shown more clearly, that the common opinion of
the relation between muriatic and oximuriatic acids is still
the most probable one, inferred by the most simple and
direct induction, and in strict conformity with the es-
tablished theory of acidity, and the chemical agencies and
combinations of acids ; while the opinion of Mr, Davy, in-
stead of being, as it has been contended, a simple expres-
sion of facts, is an hypothesis, involving assumptions gratu-
itous and complicated, and at variance with extensive and
well established analogies. The experimental proof [ have
brought forward, and which I consider as sufficiently con-
firmed, is still farther, it appears to me, conclusive in sup-
port of the opinion I have maintained. I regard the dis-
cussion on my part as closed, and I shall not be disposed to
resume it, unles:8 some new facts or arguments are adduced
ftufficiently important to demand consideration.
I am, with much respect.

Your most obedient servant,
Edhiburgh, June (he Jth, J. MURRAY.

1811.

P. S. Mr. J. Davy, in a communication in the number of On the na-

your Joor«al ibr May, haft stated » aeries of facts, from tureofthem*.

, . , talloids.

^ .^ which

102 DE8CRIPTI0N OF THE FIRS.

which he has inferred, that the opinion I had advanced
witli regard to the nature of potassium is unfounded. He
will have observed, that, in my second paper, published in
the supplement to your last volume, which accompanied
that number, 1 have taken notice of the greater number of
these facts; and, that 1 had given them due consideration
both in conducting the additional experiments of which I
have given an account, and in forming the conclusions I
had drawn. It is therefore unnecessary for me to make any
observations on his statements in their present form. The
whole subject, from the difficulties which attend it, 1 consi-
der as c>pen to farther investigation, though I may add, that,
without placing any undue confidence in my own experi-
ments, I do not consider their results as invalidated ; and,
that I still regard the view 1 have given of the nature of the
metalloids as the one which is most probable, nor shall I
have any hesitation in engaging in the more minute discus-
sion of the groi^nds on which it rests.

VII.

Description of Firs, illustrated hy Dissections* By Mrs*
Agnes Ibbetson.

To Mr. NICHOLSON.
SIR,

AranrremeTit A AM now to give a description of the fir tribe of plants,
of the fir tribe, seldom, 1 believe, studied, 4hough well worthy of attention,
as differing more in many important particulars than any
natural order of plants I am acquainted with. Though sel-
dom interfering in the arrangements of botany, I have ven-
tured to place the thujas with the cypresses, allotting the
cedars to the genera they appear to belong to. For they
haye been hitherto placed without the least regard to their
flower or fruit; else could the white cedar be called a cedar,
or the balm of gilead fir a pine? I shall divide them into
three sorts, the pine, the cypress, and the cedar, placing
the various apecies according to their fructification.

Firs

©FSCEIPTION OP THE FIRS. 203

Firs differ from plants in general io having no «piraVThey h>Te n«
vire; for these vessels are absolutely only to be found.****"*'
where the leaves require turning, and not when so fastened
on the main stem, a$ to be incapable of changing their po-
sition: an arrangement that might have been expected, since
to turn the leJtes as habit requires, to open uud shut the
flower, are the real offices >of the spiral wire.

The tir tribe differ also in forpaing their bark and rind by Theyalsofon^
leaves; for, while in common plants the juices with the J.!^^^^^^^*^* ^"*
thread vessels of the bark form together the upper covering leaves.
of the tree, in the lirs they form leaves alone; and with these
the tree is covered. The leaves of the pines are more sim-
ple in their formation than leavesi having the spiral wire, aU
that rolling and pressing is not used .n any of the fir tribe,
tiiongh the buds are more difficiiltto be understood ip their
general arrangement. To comprehend a leaf bud when
forming, you must take it out of the interior of the *' leaf
calyx", within which, and next the stem, it will be found.

The leaf bud consists of several pairs of calyxes, having The leaf l>vii»
a'l)undle of leaves weaving: as at tig. 1, Fl. V. Take one
of these, and in the solar miscroscope it will show a very
curiously worked wood, vessels ready formed ; as a middle
to the leaf, and a parcel of threads weaving the sides of
the leaf by passing backward and forward : see fig, 2, where
a a are the sides, and b b the rpiddle, through which the
threads pass. When this is done, the pabulum or blood of
the plant coagulates, and settles op the threads, forming a
mass both thick aud durable; while the cpbweb skin, which *
is woven with the calyxes, fastens on it, and covers the
vhole. Now the edges of the leaf begin to shoot, while
threads of singular fineness and beauty appear; but scarcely
have you time to admire the various prismatic colours they
reflect in the sun, ere they are covered by the same cobweb
gkin, which raakes^of these apparent glass rings (for such they
seem) one regular circular vessel; bordering the leaf, and
fastening down the upper surface: the next appearance of
the leaves is at the top of a bud, their form is then complete,
though extremely small. In this bud you see the first start-
ing of the flower bud from the line of life as at fig. 3; where
p c are the female buds, d d the leaves. No soouer has the

flower

204 pEscjiiPTjow op tut Pia».

flower bud got its scales and clothing to fit it for the cold
it may encounter, thttn the itein will lengthen, and leuve
the femule bud on rach side of the stalk ; carrying its leaves
fi>till covered by a s>ca!e) on the top ; when growing iu length,
and having now acquired a prQi>er height, for the last time
the btem begins to t>hoot, and tlie leaves push oti' the scale
as they increase, depositing their proper number at each
poiot of the stalk, according to the species. But the calyx
still remains stationary, so that the length of the stalk,
with tb^ number of leaves contained in each bud, is easily
known.
Fe<>u!iarbud There is in tb*^ pines a peculiar sort of bud, that must
in the piiies. catch the attention of the most careless. In the shape,
and with the appearance of a bud, it is in reality the spring
shoot, showing itself in Mayor June, just after the leaf
buds have made their spring increase, and when their fea-
thery tops display such beatiful green plumes, it is also
that peculiar thing, which serves to show the height the tree
gains each year, and proves, that the leaves alone form its
covering. It is the increase of the stem without the wood ;
that is, the bark and inner bark forming their shoots, while
all around the sides, closely imbedded, are found buds of
leaves, serving, as the stem increases, for the future cover-
ing of the tree. As soon as this is finished, the wood, line
of bfe, and pith shoot up in the middle, and then the stem
is completed.
iFemalebud. But this does not happen till the female bud is formed

at the top of this new shoot. At first the line of life runs
up through it, and may be seen us a few green threads, fol-
lowed by some wood vessels. The female flower is then
protruded ; and the rest of the wood begir)s to grow. This
is an uncommonly curious process, as plainly proving two
things: 1st, That the bark, inner bark, and leaves, want
little assistance from the wood : 2d, That as soon as the
pistil and stamens begin to grow, the line of life is their
first accompaniment, and then the wood. The bud, when
the female cone appears at top, is near a foot long, and
often more in the Scotch fir, in the spruce still more, and in
the silver fir less. Still it is the same thing, though rather
different in appearance.
/ * There

feEiSCIt\Pfld!> 6P THE FIRS. 205

There is' a peculiarity in the Scotch fir, and Weymouth Peculiar bloom
fine, not to be found in any of the firs, I mean the beauti- Jfralid w!^-
furl matter, which resembles the bloom of a plum, and mouth pine,
which, like that, is a cryptogamian plant of an elegant caused by «
kind ; and though its extreme thickness grows only in spots, "j^^^^^^"*®*^*
yet it is spread in a less decree over all the back of the leaf*
It comes not till the leaf it> fully formed ; and disappears
with age and sickness.

The Scotch fir is very different from the other pines in gcotch fir.
growth. If not in perfect health, and in a soil exactly suited
to it, it is but too apt to grow squalid and ugly. Indeed no
trees so directly show sickness as the firs. As soon as the Marks of ^i*-
«temof the side bough ceases to be on an even line with ^*^ *" *^
the branches that proceed from it, especially at its termi-
nation, and as soon as it stands much above them, it begins
to mark a disordered frame, and its future symptoms of
decay are as regular as the seasons. For years, the tree will
continue growing more unsightly, though it may require a
century to kill it. But when in perfection it is a beautiful
tree, and less formal than other firs. The pinus latifoiia is
a variety of thi^ species.

The stem of the pine I have In part described, the leaves Peculiar mat*
standing instead of bark and inner bark; the scales instead ^^^ *"*^^ ^'*j
of rind. But next to the bark is a matter in all firs, which
has hitherto been called by that appellation, though dif-
fering entirely from it. To inquire into the nature of this
substance, its use, and why placed there, may be worth the
trouble. On examining all those trees which have hitherto nnd in all trees
yielded the tanning principle, I find they have invariably this ^^}^^ y^*'*^ ****'
substance placed next the bark, and joining the albumen;
although it is found in no other trees. On farther examina-
tion it appears to be allotted to them in a degree of thickness
very nearly proportioned to the strength we have found in
this same tanning principle, in each tree. Thus in the
sumach it is composed of about 8 or 10 rows in thickness,
in the oak of 6 or 7; in the willow of 5 or 6 : and so on.
Now on placing a piece of this matter in the solar micro-
scope; I find, instead of being bark, it is wood formed '
exactly the same as the wood on the other side of the albu- ,
?nen. But so altered, so changed in its appearance and

feel

£0S DESCRIPTIOM or THE fIRI.

feel, that a large raagnifier alone could prove it the same :
for instead of that hard and harsh substance, it Is soft,
smooth » and pleasant to a great degree. But when I came
to dissect the firs, instead of finding a few rows of this
matter, there were 40 or 50, making two or three tenths of
an inch in thickness ; it was become so soft in every respect,
that it serves for bread in some countries. Though so
thick it will turn round the finger with the utmost ease,
and is far more succulent, more oily, and of a more beauti-
ful wliite colour, than this matter in auy other treee 1 have
' mentioned.

Use of ibis From all those observations, I think \may notice the con-

mauar. elusions I have drawn from these data, without being ac-

cused of giving way to imagination. 1 am persuaded, that
this matter, placed in this situation in the tree, is intended
to guard the albumen from being steeped in this softening
liquid, and therefore never gaining the strength requisite to
it: that the matter thus placed shows the effect of this tan-
ning principle by the extraordinary changes of its appearance: '
and that the conclusion naturally to be drawri from the whole
is, how much stronger musjt the tanning prmciple be in the
lirs, when nature is forced to have recourse to such an expe-
pedient, in such a treble guard ; and how strong must the
juices be, which have produced so astonishing an alteration,
for the wood can only be compared to beautiful white leather.
Why this matter should tear off with the bark, and leave the
wood, is easily explained, as is also the reason why at this
time the bark comes off at all. It is in the spring and fall, %
that the new albumen shoots; and it is then so soft and
watery, and its vessels, if formed at all, so weak, that the
smallest effort separates them. Indeed, at^ first it is only
a collection of the sap to form the albumen ; and they of
course then fall apart.
Wood in other As to the vvood of the pines, it is nearly the same as in
trees. any other trees; composed from the depositions of anew

row each year.

~ .^ . I shall n9vv show the fructification of the pines. There

of ihe i»ine«. is perhaps no seed, where nature so plainly and openly ex-
poses her whole process, as in this tribe of plants. So evi-
dently iudeed does she develope them to the view of the at-
tentive.

I

DESCRIPTION OF THE FIRS. ^0/

tentive physiologist, that even dissection is unnecessary. I
shall also, in describing the seed, prove the truth of all I
have hitherto advanced on this subject, and shall continue
to take ray specimens of the pines from the Scotch fir. There
is a curious particular concerning them, yet unknown I be-
lieve. The cones of the present year are not impregnated
till the following; nor are they fit for planting, or will they
come off the tree, till the succeeding season. When they
are first seen on the new shoot, the stamens have already
exhausted all their powder: besides, the cones have at that
time no seed within them. But the following May, as soon
as the stamens make their appearance, the cones, if watched,
will exhibit a beautiful sight. On each squama will be
seen two brilliant drops of liquid, the juice of the pistil,
appearing toward noon, and subsiding in the evening. For
s little time it will continue thus, till the stamen has risen
out of its calyx, and each anther hangs like a basket of
gold dust, ready to disperse in air. In a short time the
drops on each pistil get saturated, and pass down to the
seed, which they impregnate ; running the line of life, filled
with the mixed liquor, into each seed, and forming the cor-
culum. As soon as the heart is perfected, the same line
shoots lower, and produces the pocket, which is the out-
ward cuticle of the embryo, and the cotyledons,. When
the pocket is large enough it joins to the heart, and the

u cotyledons begin to grow ; and this is a long process in the

" fir tribe of plants, where there are from 5 to IQ in each seed.

^ *l know no plants so capable of proving the mistake into The cotyle-
which most botanists have fallen, ** in supposing the coty- ^^"^/^o "o*

j ledons nourish the embryo"; for though these seeds, hke embryo.

I all others, have the 8 parts perfect; yet, being of the foli-
ferous kind, they are so very diminutive, a large magnifier
is required to see them. Would then most nourish-
ment be formed, where there was hardly any embryo to
feed ? Besides, as I have before observed, the cotyledons
are a part of the embryo ; it would therefore be nourishing
one part with the other; an idea not to be supported, la
the firs also the nourishing vessels are so very plain, that all
must see them. See fig, 4 and 5.
Having now explained the Scotch firs, as an example of The cyprew

SOS

DESCRIPTION OF THE FIRS,

instanced in
the white ce-
dar.

The young

fhoot.

B?rniutlas
cedar.

Balm of Gi-
lead fir.

Thuja.

Stems o(f the
jounjr
branches.

Principal
leaves.

Peculiarity of

the firs.

all the pines, which they in fructification and habit cidsely
resemble, I shall turn to the cypress kind ; including only
those, the fruit of which bear a strict analogy to the cypress;
as the white cedar, (he balsamea, the arbor vitae, and others,
too many to name ; taking the white cedar as an ej^ample
of all the rest.

The young- shoot of the cypress kind is curious. Jt t,o
much resembles the juniper, that the most knowing garr
dener would be deceived. This is caused by the first shoot-
ing of the'leaf bud \u the axil of the leaf; which necessarily
throws it from the stalk, to which at every other time it
cleaves most closely-: for they have inbricate leaves, with the
leafing branches quadrangular, which makes them take a
pyramidical form, The Bermudas cedar is only a variety of
the cupressus sempervirens, expands more in its branches,
grows larger in size, and is that species from which th^
wood is taken, so remarkable for its resistance to the insect
tribe. The pinus balsamea, with its brown and woody cqr
rollas, has the same fructification, though the cojie is in the
former more expanded. In the arbor vitae it differs little ;
though this has generally been supposed to carry its male
and female flowers on different trees. But this I conceive
a great mistake ; I have repeatedly drawu them from the
same plant, as well as in th# balsamea.

The stems of the young branches of all these of the cy*"
press kind are more formed like leaves than stems, only that
they are so thick as. to have no edges. They are almost
wholly composed of pabulum, having very few regular ves-
sels. A quantity of smaller bubbles of resinoas matter,
surrounded by a net work enclosing naw and then a larger
circular bleb. Thus net on net appears to form both the mi-
nor branches and leaves: but the principal stems are com-
posed as those of firs in general ; except, that in the larger
stem of all firs there is a peculiarity not yet noticed. In
showing the interior formation of trees, I mentioned the grand
obstruction, and the middle*. This last was the stoppage
of the pith at the commencement of each branch. Now

• See Journal, rol. XXVUJ, p 259, 260.

when

I

DESCRIPTION OF THE FIRS. gQQ

when a branch is divided in the firs, the wood as usiial is
perceived to supply the place of the pith ; but in the middle
of the wood is a square of pith proportioned to the size of
the branches, which is seen in the jBrs only. In all firs there
is very little pith : possibly therefore it may be intended to
supply the moisture necessary to raise the wood for the pass*
ing of the buds : for in the firs almost all the buds may be
seen passing from the line of life to the exterior in this very-
place; and perhaps no plants give more complete conviction
to the mind respecting that important point, namely, whence
the flower buds proceed, than the firs ; for they are seen
proceeding in every direction from the interior, and throw-
ing off their female cones as the stem increases.

The leaves are formed with a large bladder in the middle. The leases*
and a thorn at top.

The fructification is very diiferent from that of the pines, xhe fructifica*
Fig.7isasiuglesqnamaof the cone of the cedar thyoides; fig. tion.
8 is a squama dissected; and fig. 1, PI. VI, isthe male anient.

I now turn to the real cedars, at the head of which may Cedare.
be placed the cedar of Lebanon. With these I have joined
the larch, and all those the leaves of which grow in bun-
dles. In fructification they much resemble the pines ; but
their nature agrees not together; and if any should be se-
parated beside the cypress, it should certainly be these.
They are hardy, and brave every climate, from the hot
Bermudas to the moist Barbadoes, and the cold New Eng-
land, and grow in perfection in all. They grow also in the
bogs of America, and on the mountains of Asia. The ce-
dar we have from Jamaica is a spurious sort ; and the wood
so porous, that wine soaks through it; while that of Caro-
lina (probably a true cedar) is so firm and close, that it
often preserves the strongest spirits in vigour. In this coun-
try none of these firs have any scale, or covering to their
leaf buds; and they are also perfectly alike in their manner
of forming their leaves. It is curious, that in the pines, Leaves,
where the leaves are few, or in pairs, they weave in bundles;
and in the cedar, larch, Sec, where they come out in bun-
dles, they weave singly. There is no apparent leaf bud ;
the whole work is formed within. Each separate little calyx
has a bundle of threads, which it Witids round the long

Vol. XXIX— Jvly, 1811. 1P vessels.

■V- r

2ld »ESCRlt»TION OF THB 1^1R«.

vessels, workiog them in and out like basket work, thtf»
binding them to the middle wood vessel. But bo sooner
are the leaves formed, though ever so diminutive, than the
^Ik shoots, carrying up the leaves with it, and another
general calyx forms round the parcel of leaves ; the single
calyxes remaining to bring out fresh ones, and to serve to co-
ver the new stalk. The edges of the leaves are formed very
differently from those of the pines. A parcel of threads,
very clear, and apparently full of water, are found shooting
by the side, and binding themselves to the leaf by a single
thread. In some of the real cedars there are two, in some
three, and in the larch four of these vessels.
Peculiarity in There is a peculiarity in the cedar of Lebanon so very
t ece arot extraordinary it must not be passed over. The upper cover-
ing of the trunk of the tree seems as if too long for it, and
sits in high ridges all the way, appearing as though, it
stretched out in length, it would be as long again. It
would be very ini^tructive to know whether this is the case
in its native land. I have lon;^ been seeking for the ball und
>sbcket found in some plaiits, and peculiarly marked in some
Tirs, where the branches have missed. In the cedar I was
much struck with this appearance, and resolved to try whe-
ther I could find the balj. On cutting round it, it moved
under my hand, and I found it was easily taken out. I
have now procured ten of them, some formed like a pointed
top, some merely circular, but the bark and rind, instead
of being, like that of the rest of the tree, formed of thick-
' ened leaves, are divided into narrow slips of bark and> rind,
' rolled, and covering it like basket work.
Another pecu* There is also another peculiarity never seen in our forest
lianty. trees, and which appears to belong only to the exotic trees;

a projection round the part where the branches first shoot.
* if they have it not in their own climate, it may be an in-
crease to strengthen tbem, weakened by growing in a foreign
country. ' - . .

Fructification. I shall not occupy your p!%es with describing at length
^ ' the fructification of the cedar, as its process very nearly re-*

sembles the account already given ; but mention only, that
Abundance of its cone is extremely large and solid, and appears to con-
tanniii. tain 'a greatei: quantity of the tanning principle than any

••' ' - ' other

I

i)ESCRII*TlON OF THE PIR*. fill

Other part. The seeds are not only full of it, but are
covered without by bladders filled with the same juices.

As I have now concluded my account of the firs, 1 shall Wood
finish with a few words respecting wood in general, as one of
the most important subjects in the botanical world. Some of
our best physiologists have made a strange mistake, if I may
venture to say so, in supposing it impossible that the wood capable of con-
can convey sap, because the wood can be torn to atoms* ^^^^"^^^P*
Look in the microscope; at one of these shreds, and it will
be found pointed, not a sap vessel, but a fragment. The
sap vessels are round, but the wood has besides the bastard
pipes, pieces of thin flimsy texture> which fill up all the
places between the sap vessels, and sire very large in young
wood, and will divide into hairs; which are often taken for
important vessels. The sap vessels also will separate, but
I cannot conceive their being thus flexible, and easily torn,
lessens their power of conveying sap when perfect and
whole. But is it not an easy thing to prove, that they art
the real sap vessels ? since they are the only pipes yet found
in plants, that will convey coloured infusions, as ail ac*-
knowledge. I have repeatedly taken a branch three or four
feet long, and though 1 could not make the coloured mix-
ture rise the whole space at once ; yet by cutting a little
below where it stopped, 1 have made it by degrees rise the
whole length, and thus proved, that there is no real stop-
page in the vessels ; but that the sap is capable of flowing
in one even current from the bottom to the top of the tree;
and the only reason we cannot make coloured liquids rise
with the same ease and quickness as the sap is, that our
mixtures are not so well tempered as Nature*s: there is al-
ways some dust, some matter to choak these little pipes. I
once made some very curious experiments on capillary at-
traction, in very diminutive glass pipes, wl^ich rendered thi;*
most evident, not only between the liquids, but between the
pipes which we make when compared to the perfect works
of Nature,

As I cannot believe, that any one can strip off the bark Flower budj
of a tree, and yet be doubtful whether the flower buds ^^o''*/^® '°*^
come from the interior of the wood, I am very anxious to
persuade the physiologiit to study at this seftson the tree

P 2 ftewlr

£12 DESCniPTlON OF THt TIER.

newly barked. There he will not only see the buds ju»t
breaking through, but the variation in each different tree in
this respect-— the manner in which each point of the com-*
pass is marked by its growth, by the scarcely undulating
line of the sap vessels in the north, and by their never end-
ing half circles in the south.

I am, Sir,

Vour obliged servant,

AGNES IBBETSON.

Explanation of the Plate*

PI. V, fig. I. A bundle of leaves taken out of the inner
leaf bud of the Scotch fir, while weaving; with their ca-
lyxes.

Fig. 2. A single leaf much magnified, and showing the
manner of forming all the leaves of the pines.

Fig. 3. A sort of general or mixed bud in the Scotch fir,
when the leaves, d d, are completely formed, and they are
discovered at the top of a bud ; while the female cones, c c,
are shooting from the line of life, though not one in ten
lives to come out of the cradle in the bark, pp.

Fig. 4. The squama taken out of the Scotch fir. a a
ihe pistil : o o the two drops : b b the line of life running to
the seed, and entering it, to form the heart at/: c the
nourishing vessels entering the seed at dd: and fastened to
the cone at ^ e.

Fig. 5. The male collection of stamens or catkin.
, Fig. 6. A single stamen with its scale.
"^ Fig. 7« A squama of the cypress kind, taken from the
wTiite cedar.

Fig. 8. The same dissected: h the pistil: iithe drops
appearing to catch the powder: kky the line of life passing
into the seed at r r. / the nourishing vessels passing into
the seeds at 7iM, and then joining the cone at mm.

PI. VI, fig. !• The male catkin of the cypress kind.

IX.

MOTtOK or THE FLOWER OF THE BARBEERY. %\S

IX.

On the Motion of the Flower of the Barhirry. In a Letter -* t

from Mrs, Agues iBBETSOH, . *'

To Mr. NICHOLSON.
SIR,

.S the berberis has been the subject of a letter from one Motion of the
of your correspondents, 1 have waited till the flower was in flower of the
full beauty, to send you a sketch of the manner in which
the whole motion is managed by the spiral wire, I>r. Smith
has most properly observed, that it is a contraction of the
stem (for it can hardly be called a tilaraent) of the stamen :
it is so; for the contraction is in the spiral wire within this
stamen stalk, which is gathered up, as may be plainly seen,
when put into the solar microscope. Pi, VI, lig. 3, b 6ns
the corolla, a a the stamen fastened to it—it has also a
fastening to the pistil, which, crossing from each side to the
pistil and round it to the other stamen, makes a general
communication, but not a very sensible one. The strong
spiral wire, o o, that manages the flower, runs through the
middle of the stamen e c, with two joining from the sides
d d, and running into the nectaries, ff, in which they are
fastened at g g*» So uncommonly strong is this spiral wire,
that it is larger than that which manages many flowers of
three times the size. There are many cross spirals, for it is '
rather a complicated management; but this will at least
account for the contraction that takes place from a to a,
and is plainly to be seen. The same thing happens in the
stalk of many plants when in bud, which alter their posi-
tion when full blown. On placing a bunch of these flowers Yh9 flowets ^
under water, it is very difticult to make the water ^et to ^'i' ' tnove
them ; but if they are once thoroughly wet, they move uo lihe'tuhl^^*'^
more. However I again repeat what I have said in my last roughly wel,
letter, that I cannot say I am myself convinced what is the

• PI. VI, fig. 2, a a, shows the stem of ihe stamen of the l^rberry ii
its perfect state ; and fig. Q, a a, th« stem cat open t» expose the cases

of the spiral wire. .1 *

powery

^14 CUlTrRE.OF THB ALPINE STEAWB-ERRY.

power, which rules the spiral wire: but that this wire is the
cause of the naotion, whatever may be the superior cause
that regulates it, I aai hourly more and more convinced,
frtructureofits The berberis is curious on another account; its corolla is
corolla very peculiarly made, something lii^e the watery corolla,

but not quite ; no one can look at it, and not see that it is
water, which causes all the beauty of its light and spark-
ling appearance.

J am, Sir,

Your obliged servant,

AGNES IBBETSON,

X.

j4n improved Method of cultivating the Alpine Strawherry,
By Thomas Andrew Knight, Esq, F, R, S., ^c*

Culture of the ^ ^^^ Strawberry is a fruit, which is agreeable to the pa-
Alpine straw- lates of so many persons, and which disagrees with the con-
"^* stitutions of so few, that any means of improving the culture

of it, and of prolonging the season of its maturity and per-
fection, will probaby be acceptable to the Horticultural
Society; I am therefore induced to send an account of an
improved method of cultivating the Alpine strawberry, that
jg, I believe, little, if at allj known, aud that I have prac^
tised with the best possible success,

„, . Thouiih the flavour of the Alpine varieties is generally

Valued as an =7 i i i /. i ., » ,

autumnal approved, they are not much thought or, while the larger

*^''°P' varieties continue irt perfection, and are valued only as an

Experiments 2"^"™""' crop. I was therefore led to try several different

' ^ methods of culture, with a view to obtain plants that would

just begin to blossom at the period when the other varieties

cease ; conceiving, that such plants, not having expended

cither themselves or the virtue of the soil in a previous crop

of fruit, would afford the best and most abundant autumnal

]^roduce. Under this impression X sowed the seeds of

♦ Trans, of the Horticultural See. vol. I, p. 169.

the

ON THE NATURE OF HEAT. J^15

the best alpine variety, that I had ever been able to obtain, Seeds sowed in
in pots of mould, in the beginning of August, the seeds of "6^*'*
the preceding year having been preserved to that period ;
and the plants these afforded were placed, in the end of
March, in beds to produce fruit. ,*'^

This experiment succeeded tolerably well ; but I was not ^he plarrt^ "'
quite satisfied with it; for though my plants produced an j^o ^arly,
abundant autumnal crop of fruit, they began to blossom
souiewhat earlier than I wished, and before they were per-
fectly well rooted in the soil. I therefore tried the experi- Seeds sowed
laent of sowing some seeds of the same variety early in the
spring in pots, which I placed in a hotbed of moderate
strength in the beginning of April, and the plants thus
raised were removed to the beds in which they were to re-
main in the open ground, as soon as they had acquired a
sufficient size. They began to blossom soon after Midsum- y^®^^^*^ ^'"*'
mer, and to ripen their fruit towards the end of July, afford-
inga mostabundant autumnal crop of very fine fruit; and even
80 late as the second week in December I have rarely seen a
more abundant profusion of blossoms and immature fruit

than the beds presented. The powers of life in plants thus Should always

. , , . , . 1 be treated as

raised, being young and energetic, operate much naore ^n annual.

powerfully than in the humours of older plants, or even

in plants raised from seeds in the preceding year; and

therefore I think the Alpine strawberry ought always to be

treated as an annual plant.

xr.

On the Nature of Heat. By Marshall Hall, Esq, In a
Letter from the Author,

To W. NICHOLSON, Esq.
SIR,

JL HE nature of caloric has long been a subject of inquiry Nature of ca-
in chemical philosophy. The first conjecture on this m&t- jTuestionwl
ter, which deserves attention, is that of Lord Bacon; his Hypothesis of
opinion has, however, been in a great measure superseded Bacon.

<g|g ON THE NATURE OF HEAT.

by the hj'pothesis of Homberg and Boerhaave. It may in-
deed be observed, that while the opinion of the materiality
of (JkloHc has had many adherents, and received much con-
sider^ation, the hypothesis of Bacon has probably been too
much neglectej^; nay, it has even been held up to ridicule
and contempt, as a ** delusive dream," or as a ** labyrinth
of perplexities." Probably the reason of this censure has
been just given ; had the opinion obtained the consideration
which it nierils, it would possibly have long since ceased to
be this labyrinth of perplexity.

I trust therefore, that a few observations on this subject
will not be altogether unwelcome: no apology can be re-
quired for their iinperfeciioijfa, I shall commence with a
few remarks on the prevailing opinion, and shall then give
a concise view of what may be termed the hypothesis of vi-
bration,

1, Sotirces of caloric.

Sources of Scarcely any circumstance can aiford more forcible ob-

heat. jection to the hypothesis of material caloric, than some of

the means of producing an increase of temperature. Every
one is acquainted with the important researches of Bogle,
Romford^ and Davy, on this subject. Their experiments
prove, that lieat may be produced by friction in circum-
stances, where no source of it, considered as a material
agent, can be discovered or suspected.

But these facts have been so often urged as imcompatible
with the supposition of material caloric, that it is needless
to enter farther into the discussion of this point. I wish ra-
ther to avail myself of this opportunity, to consider other
parts of the doctrine.

Under this head it may indeed be added, that the ex-
citation of heat, in the operations of electricity and galva-
nism, has not been explained. There is also much difficulty
in accounting for the production of heat in some instances of
cpmbastion^, and of other chemical actions.

♦ Thomson, yol. I, p. 575 et seq. 3d cd*

2. 3Iotion

ON THE NATURE OF HEAT. 2 IT

2. Motion of caloric*

It is observed, that the best conductors of heat receive Motion of
and deliver it most easily and rapidly; those bodies, wbich. "
absorb heat with most avidity, are also such as radiate most
copiousl3\ The first part of these operations nniight be
ascribed to the attraction exerted between the particles of
the body and o! caloric ; but the second pheuonnena are
directly adverse to such an explanation. Considering calo-
ric as matter, and subject to attraction like other matter,
the circumstances above related appear to require explana-
tion.

In the radiation of heat many phenomena occur, which Radiation of
have not been satisfactorily explained: and first, the re- ^^^^^
markable difference between solar and culinary heat does Difference be-
not appear to be by any means understood*. The first is J^^JJ ^!&fir^
transmissible through and refrangible by glass, and other
transparent media; the second is in a large proportion inter*
cepted by every solid body : the first is reflected in circum-
stances, in which the second is absorbed t : culinary heat,
unlike the solar ray^ suffers a considerable aberration in its
reflection : and lastly, the absorption of culinary heat is not
affected by the colour of the absorbing surface, in the same
manner as that of solar heat J. What can be the cause —
what the rationale of these differences ?

It is however in the radiation of cold, I conceive, that we Radiation of
have the most forcible and direct objection to the hypothesis ^°"^*
of material caloric, and the most certain indication of the
real nature of this principle. It is scarcely necessary to
say, that no unexceptionable explanation of this phenome-
non has been proposed. According to Prevost's supposition,
the effect of radiation from a cold surface ought i« reality
to be that of heating, and not of cooling the opposed ther-
mometer ; this will be rendered evident by the assistance of
a diagram.

PI. VI, fig. 4, ah, cd, are two concave mirrors. TacI^
Tb dl are rays of heat issuing from the thermometer,
X c a T, IdbTi i^re rays also of heat, issuing fronj the iee ;

• Nicholson's Journal, vQl.yiii, p, 297.

t LesUe^s Inq. p. 83, et seq. % lljid, p, 97.

for.

OJ^ ON THE NATURE OF HE>IT.

for, according to the hypothesis, both the therniometer and
the ice radiate heat. The thermometer T however radiateg
- . to the ice I more than the latter does to the thermometer ;
the ice therefore receives caloric, and will be dissolved; but
the ice also radiates caloric ; this will be reflected and con-
veyed to the thermometer, which will consequently main-
, tain a higher temperature, than if there were no ice, from

which it could receive caloric.
CoontRum- ** Count Rumford, not admitting the existence of ca-
ford ascTkbes « \0y\q as a distinct matter, endeavours to explain the phe-
heat to undu- «. i- i <. i i i • o i i

lations. *' nomena ot radiant heat from the hypothesis of undula-

•' tions excited by bodies at a high temperature in an
" etherial medium," — The Stahlian theory accounted for
the phenomena of oxidation, while philosophers neglected
the agency of the atmospheric air in the operation ; and in
a similar manner the hypothesis of Count Rumford might
explain the radiation of heat and cold, could we forget the
PifFicultie^ in manifest influence of the " ambient air,'* Other difficulties
ihtehypothe- -^ ^^^j^ hypothesis would occur, in applying it to explain
the diflerences between solar and culinary heat; and in ac-
counting for the partial interception and partial transmis-
sion of culinary heat by transparent media.

This partial transmission of culinary heat, and its distri-
bution in the prismatic spectrum, do not appear to admit
of explanation on the ingenious hypothesis of Mr, Leslie.

With regard to other attempts, which have been made
to explain the radiation of cold, and to reconcile it to the
general theory, complete satisfaction may be obtained from
consulting Mr, Murray's work.

3. Effects of caloric,

Effictsofheat. The opinion respecting the mixture of material heat
arises chiefly from the considennion of the eff*ects, which
the comma ni cation of temperature occasions on the bulk
and form of bodies submitted to its action. The explana-
tion, which the hypothesis affords, of the immediate effects
of heat, is indeed often satisfactory ; yet, although it ap-
plies in many cases, it fails altogether in others ; and cannot,
I conceive, bear the test of a strict examination.

Fxpartds bo- j. If the hvpothesja were true, exp'ansion ought invaria-
dies generally, ' bly

ON THE NATURE OF HEAT. 1249^.

bly to attend an increase of temperature, and contraction,
ought constantly to accompany its diminution.

It is scarcely necessary to mention the contradictions to but not always,
this law, observed in our operations on water, iron, and
some saline solations, while ihey retain their fluidity; on
water, iron, bismuth, antimony, sulphur, the saline bodies,
&c. djring their transition from a solid to a fluid form; and
on arj^il at high temperatures.

In the liquefaction of ice, iron, sulphur, &c., the con-
traction in bulk is very considerable ; yet during the ope-
ration, from the temperature acquired, and especially from
the increase of capacity, a very great quantity of caloric is
supposed to be absorbed.

'2dly, The degree of expansion ought, ceteris paribus, to Expansion not

be in direct proportion to the quantity of caloric absorbed. '" ptoportion
^T - \ n , . ,. , • •• to the heat

Now as m changes ot temperature those bodies, which supposed to be

have the greatest capacity for caloric, absorb the greatest absorbed*

quantity, it follows, that their expansibility ought to be

proportionate to their capacity. This is however by no

means the case, as will be observed by the inspection of the

following table, in which the expansibility and th« capacity

of several of the metals are compared.

Capacity. Expansibility.

Iron -98982 ..•• 10012G

Copper -98823 ••.• 100170

Zinc •• -64099 , 10029e

Antimony.. •• -43292 •.•• 100109
Lead -39959 • • • • 100287

Of these metals, iron and lead occupy the extremes in **

capacity; iron having the largest and lead the least capacity
for caloric ; yet lead is the most, iron the least expansible by
heat: that metal, therefore, which absorbs the most caloric,
expands the least; and, on the other hand, that which ab-
sorbs the least of this repulsive fluid, expands the most!
The same discrepancy is observed in other parts of the ta-
ble; antimony and lead have a capacity nearly equal, yet
they occupy the extremes, in the scale of expansibility. ^

Aware, however, that the expansibility of any body might This a^parent-
be regulated altogether by the degree of cohesion between ^^ °ot owing

its " *^" ^*'°^*

220 ®* THF NATURE OF HEAT*

its particles, I examined the same circumstance in thoge!^.
bodies, the form of which precludes the operation of this'^
case, at least to any very considerable extent. The follow?
ing table will show the result.

Capacity,

Oxigcn gas 5*23&147y

Hidrogen gas 1 80.0 - / g ^^^ji^ijit

Atmospheric air r7i>* > \,^,,„j ^

Carbonic acid gas l>5681 l *"'*"'*'•

Nitrogen gas ..'.......• '78169 j

All gasses then arp found to expand in an equal degree
by the same change in temperature; yet how widely dif-
ferent are the respective quantities of caloric absorbed!
From the above table it appears, that, during a given in-
crease of temperature, carbonic acid gas absorbs a quantity
of caloric more than twice as great as the same bulk of ni-
trogen gas; atmospheric air, and hidrogen gas absorb a
quantity still more considerable ; and oxigen gas actually
absorbs more than fi\; times this quantity; and still the ex-
pansibility is precisely the same in all.

It is certainly needless to add any remarks on facts such
as these; they are indeed truly important. One portion of
caloric, the principle of repulsion in these operations, oc-
casions an expansion in one case equal to that which 6^
times this quantity does in another : this effect too takes
place, when no cause occurs^ to regulate or influence it.

4. Capacity for Caloric,
Capacity for The phenomena of the capacity of bodies for caloric ap-
^^^ pear to me, to be adverse to the opinion of its materiality.

Caloric is the supposed cause of temperature and of ex-
pansion ; yet we communicate caloric to ice, at 32" Fahr.,
without an increase of its temperature, and with an actual
diminution of its bulk. Here then our material agent hag
forgotten its functions, and we are obliged to resort to a

• This statement from calcuUtion agreei neailjf with the results of
Mr. Leslie^- expcrVments on these two gasses* The same may be said of

thp oxt'^en and nitrogen gasses; ^ . zz 1*8958 which,

4
all circumstances considered, is wc^nderfaJly exact, '

new

ON THE NATURE OF HEAT. g£|

new hypothesis, to reconcile the contradiction: for I CfkB
regard the doctrine of capacity in no other light, than'ih
that of a second hypothesis, adopted to obviate the imbeci-
lity of a former one.

The objections afforded by this part of the subject, to the
general theory, are too palpable to need to be insisted on.
If it be argued, that our notion of capacity supposes a
power of cotinteracting the usual properties of caloric ; as
the properties of acid and alkali mutually neutralize each
other; there are facts not less in contradiction to this sup-
position. Thus the caloric communicated to boiling
water is expanded in satisfying its increased capacity ; ne-
vertheless the expansion occasioned is prodigiously great.

It has indeed been asserted, that there are direct proofs of
the existence of material caloric ; it h therefore proper, that
we should consider these.

1st, *♦ The communication of caloric through a vacuum, Comniunica-
has been regarded as such a proof." In opposition to this ^'°" ^f heat
argument it is sufficient to slate, that no absolute vacuum, cuuh"aot
as far as we know, has ever been effected. Cavallo could proved.
never render the sound of a bell even perfectly inaudible,
although he employed an air pump of the best construction*
And in the Torricellian vacuum it is well known, that luj
atmosphere of mercurial vapour is formed. Pictet has
even observed the condensation of this vapour. By this
vapour therefore may the heat be communicated, although
not material ; its tenuity affords no objection ; the con-
ducting power of bodies does not observe the ratio of their
density. ,,

It is obsei-Ved, that the conducting power of the Torrl- Radiation of
cellian vafcuum is to that of the atmospheric air as 100 to l^eat faciliuted
r. H.T 1 • /» 7 • . • • by the air.

o05. ^ow this presents a tact, which it is not easy to recon-
cile to the material theory. According to this theory, the
radiating power of any body must depend on its own nature
and power ; it canriot be assisted, it may be opposed, by
Burrounding bodies ; but the fact just stated, and the expe-
riments of Mr. Leslie, prove, that radiation is in reality fa-^,
cilitated by the surrounding air.

2dly, ** The radistion of caloric appears to be another une^ Radiatioa of

quivocal heat

S22

COMBINATIOI^S OF OXIMURtATiC GAS AND dXIGEtr<

quivocal proof of its materiality. A matter is thrown from
heated bodies, which moves in rip^ht lines, with velocity,
raises the temperature of any body, on which it falis; and
which, in every state, preserves the properties of caloric*'*

no proof of its But are these proofs of materiality? By no means. If
every thing were material, of which these properties could

, be predicated, then should we have proofs of something sub-

stantial in sound and cofd. Thus sound is thrown from sur-
rounding bodies, in right lines, with velocity, is capable of
reflection and of condensation, occasions sound in some bo-
dies on which it falls, and, in every state, preserves the
properties of sound. Cold also moves in right lines, with
velocity, suffers reflection and condensation, lowers the
temperature of bodies, and is always and absolutely cold.

** Lastly," it is said, that " the existence of caloric, in
the rays of the sun, apart from visible light, adds to the
proof, that a peculiar matter exists, possessed of the pro-
perties of caloric, and distinct from every other."

It is sufficient to have mentioned this last alleged proof
of the existence of material caloric ; its validity rests en-
tirely on the supposition, that no other explanation can be
given of the phenomenon; and it will consequently fall to
be considered, in the second division of our subject.

fTo be concluded in our next, J

Heat of the

Sun distinct
fiom light.

This will be
considered

hereafter.

xu.

On iome of the Combinations of Oximuriatic Gas and Oxigen,
and on the Chemical Relations of these Principles to in-
flammable Bodies. By Humphry Davy, Esq, LL, D.
Sec, R, S. Prof Chem, R. L F. R, S, E.

(Concluded from p, 1 27. J

5. On the Combinations of the Metals of the Earths with
Oxigen and Oximuriatic Gas.

Muriates of -^ HE muriates of baryta, lime, and strontia, after being
the earths not a long time in a white heat, are not decomposable by any

simple

lldilBIKATIOKl OF oltMURlATlc'cAS AND OXIGGN. igJSl^

simple attractions: thus, they Are tiot altered by boractc decomposable

:acid, though, wKen water is added to them, they readily "'"'^^"^ water.

^afford muriatic acid and their peculiar 'earths.

From this circtiriistance, I was indnO^d to believe, that Compounds of

these three compounds consist Inerely of the peculiar me- metals wuh
. , . , r 1 11- • oxmmriatic

tallic bases, which I have named bavuim, strontium, and gas.

culcium, and oximuriatic gas; and such experiments as I

have been able to make, confirm the conclusion.

When baryta, strontia, or lime, is heated in oximuriatic Theearths
gas to redness, a body precisely the same as a dry muriate is p^^^ ^^ o'x'gea
formed, and oxigen is expelled from the earth. ^I have *or two ©f oxi-
never been able to effect so complete a decomposition of™ ^^*^&^'
these earths by oximuriatic gas, as to ascertain the quantity
of cxigen produced from a given quantity of earth. But
in three experiments made with great care 1 found, that one
of oxigen was evolved for every two in volume of oximuri-
atic gas absorbed.

I have not yet tried the experiiment of acting upon oxi- Direct union
muriatic gas by the bases of the alkaline'earths ; but I have ""^ y®^ *"'^*:
not the least doubt, that these bodies would combine di- ♦**

rectly with that substance, and form dry muriates.

In the last experiment that I made on the metallization Earths pro-
of the earths by amalgamation, I paid particular attention ^jj^^-^ metaTuc
to the state of the products formed by exposing the resi- bases,
duum of amalgams to the air, I found, that baryta formed ..-^n •»»»*ff:H
in this way was not fusible at an intense white heat, and '^^ • "-*
that strontia and lime so formed gave off no water wheft
ignited. Baryta made from crystals of the earth, as Mr. not hydrates
BevthoUet has shown, is a fusible* hydrate ; and I found, that n*on gjlr^JI^
this earth gave moisture when decomposed by oximuriatic ,^k^.*,i#-j^
gas; and the lime, in hydrate of lime, was much mor^ '^^ -!•«

rapidly decomposed by oximuriatic gas than quicklime,
its oxigen being rapidly expelled with the water. -■ •u-:f'.^^

Some dry quicklime was heated in a retort, filled with Dry quicklime

muriatic acid gas: water was instantly formed in jjreat ^®^^''** '" ™"*

" •' o natic gas.

abundance, and it can hardly be doubted, that this arose

from the hidrogen of the acid combining with the oxigen of
the lime.

As potassium so readily decomposes common salt, I Action of pot-
thought it migh". posoibly decompose muriate of lime, and *"*""» o" ^*

thus

jJ24 COMBINATIONS or OXIMUItliTte 6At ANB ^XXCSfEN.

jttttriatesof thu5 afford easy means of procuring calcium. The rapidity

the eatths. ^j^j, which muriate of lime absorbs water, and the diffi-
culty of freeing it even by a white heat from the laat por-
tions, rendered the circurastao/:es of the experiments unfa-
vourable. I found, however, that by heating potassium
strongly, in contact with the salt* in'a retort of difficuUly
fusible glass, I obtained a dark coloured matter, diffused
through -A vitreous mass, which effervesced strongly with
water. The potassinm had all disappeared, and the retort
had - received a heat at which potassium entirely volati-
lizes. 1 had similar results with muriate of strontia, and
(though less distinct, more potassium distilling off unaltered)

V with muriate of baryta. Either the bases pf the earths were

wholly or partially deprived of ojcj muriatic gas in .these

processess, or the potassium had entered into triple combina-

tjtion with the muriates. I hope on a, future occasion to be

able to decide this point. • ,^

Combination Combinations pf muriatic acid gas witii magnesia,, a^lui*

oj magnesia, mine, and ailex, are all decomposed by heat, the acid being
adumtne, and ' \ , V • ■ r \ »

sa«x, with anven otr, and the earth remaining free. 1 conjectured

muHatic gas. from this circumstance, that oxirauriatic gas would not expel
oxigen.irpm t|ie<ie eapths,vand the *uspidon %tft«,ftdhfiMned*
by experiments. I heated inagnesia*, alumine, and silex to
redness in oxi muriatic gas, but no change'tbok p;ace. '
Bzrjtes ih» Messrs. Gay- Luss^c an4 Theqard have shown, that baryta^

sorbs oxigcn. |g capable of absorbing oxigen ; and it seems Ukety, (as, ac-
cording to Mr. Chenevix's experiments, most of the earths
are capable of becoming^ hyperoximuriates) that peroxides
of their bases must exist. ■ .'^*-.
Lii!»enpp9» ' endeavoured to combine lime -with more oxigen, by

rcQtly not. Ideating it in hyperoximuriate of pHtash, but without success,
at least after this process it^ave off no oxigen in combining
Oxiauriate. withvwater. cl^e salt, call^ed'oximufiate of lime, made for
tho use of the bleachers, I found gate off oxlgdrby heat,
and formed muriate of lime. "^

S'f ^'^°' * ^'*^'" ^^^^ experiments 6f Messrs Gay-Ti)ussac ahdThenard, BuU

oximnriatic ^®^' <J^'a^oci^^- P^il. Mai, 1810, it appears, tha oxigf-'n 'S focured by
gas and mag* passing oxiinuriatic gas over magnesia at a high temperature, and that a
nesia. muriate indeci^mposable by heat is produ^-vl,' They attribute the pre-

sence of thisoXigpii to e decqmposit n o the aci '; b t, according to
. all analogies, it must arise fiom the decomposition of the earth.

From

liOMSt^fATIOTfS OF OllMt^tllATic 4ikS Aitt OXIGEIC* g£5

From the ][)roportions whicli I have given in the last Component

Bakerian lecture, but which were calculated from the ana- partsof the

. . earthy zDurt*

lyses of sulphates, it follows, that, if the muriate of baryta, ate&»

strontia, and lime, be regarded as containing one proportion
of oxi muriatic gas, and one of tnetal, then they would con-
sist of 71* barium, 46 strontium, and 21 calcium, to 32*9
of oxi muriatic gas.

To determine how far these numbers are accurate, 50
grains of each of these muriates, that had been heated to
whiteness, were decomposed by nitrate of silver, the preci-
pitate was collected, washed, heated, and weighed.

The muriate of baryta, treated in this way, afforded 68
grains of horn-silver.

The muriate of strontia 85 grains.

The muriate of lime 125 grains.

From experiments to be detailed in the next section, it Horn silver,
appears^ that horn-silver consists of 12 of silver to 3*9 of
oximuriatic gas, and consequently, that barium should be
represented by QS'l, strontium by 46-1, and calcium by
50-8.

4. On the Combinations of the Common MetaU with Oxigen

and Oximuriatic Gas.

In the limits which it is usual to adopt in this lecture, it Combinations

will not be possible for me to eive more than an outline of **^ °^'.'^""**^' ^
, • 1. T 1 1 1 , . ^^5 with mo. ?

the numerous expeniuents, that 1 have mt^de on the combi- tals.

nationsof oximuriatic gas with metals; I must confine my- •
self to a general stateme»t ofthemodeof operu in^- a d the
results. I used in all cases small retorts of green glass.

containing from 3 to (i cubical inches, furnished with stop- J?.^^!iBI^
cocks. The metallic substances were introduced, the riN ' '

tort exhausted and filled with the g»s to be a ed u oon, heat
was applied by means of a spirit lamp, and after cooling, the
results were examined, and the residual gas analysed.

All the metals that I tried, except silvei, 1 ^d, nickel, MetaU l^tiA
cobalt, and gold, when heated, burnt in the oximuriatic ''^ ^'* \

gas, and the volatile metals w th fla ac. Ar.ei,.c .^mi-

* If Mr. James Thomp8on*g analysis of sulphate of baryles be znadf
the basis of Calculation, sulphuric acid being estimated as 30, then the
number representhig barium will be abuut 05 5.

Vol, XXIX,— Juir, 1811. Q mony>

k

256

Product from
UTienic,

antimony,

t«llurium,

mercury,
zinc.

copper.

manganese,

COMBIN4rj9,!(»,9F PXIMJJRI^TIC CAS AND OXIGEN.,

mony, tellurium, and zinc with a white flame, mercury with
a red flame. Tin became ignited to whiteness, and iron
and copper to redness; tungsten and manganese to dull
redness ; plutina was ^c^rc^J^ 9f^i^^ upon at the heat effu-
sion of the glass.

The product from arsenic was butter of arsenic ; a dense,
limpid, highly volatile fluid, a nonconductor of electricity,
aud pf high specific gravity, and which, when decomposed
by water, gave oxide of arsenic and niuriatic acid. That
from antimony was butter of antimony, an easily fusible
and volatile solid, of the colour of horn-silver, of great den-
sity, crystallizing on cooling in hexaedral plates, and giv-
ing;, by its decomposition by water, white oxide.
- The product from telluriurajjn its sensible qualities, re-
sembled that from antimony, and gave when acted on by
water white oxide.

The product from mercury was corrosive sublimate. That
from zinc was similar in colour to that from antimony, but
was mych less volatile.

The combination of oxirnuriatic gas and iron was of a
bright brown; but having a lustre approaching to the me-
taUic, and was iridescent like the Elba iron ore. It volati-
lized at a moderate heat, tilling the vessel with beautiful
minute crystals of extraordinary splendour, and collecting
in brilliant plates, the form of which I could not determine.
When acted on by water, it gave red muriate of iron.

Copper formed a bright red bfowa substance, fusible at
a heat below redness, and becoming crystalline and semi-
transparent on cooling, and which gave a green fluid, and a
green precipitate by the action of water*.

The substance from manganese was not volatile at a dull
red heat; it was of a deep brown colour, and by the action
of water becfune of a brighter browQ ; a muriate of manga-

Resinof cop*
per.

• It b vrorth inquiry, whether the predplt^c from oximoriate of cop-
per by water is not a bydratedsubmuriate, analogous in its compositioa to
the crystallized muriaieof Peru. This last 1 find affords muriatic acid and
water by iteat. - .

Xhe resia.of copper discovered by Boyle,; formed by heating copper
with corro?^!^ jitrbUmate, probablv contains only 1 propottion of oximu-
rianc gas, -.vluic that cxbov^ referred to lyiust contain 2.

_ ,-. iiese,

COMBINATIONS OF OXlMURIATIC GAS AND OXJOEN. 2g7

nese, which did not redden litmus, i'emained in solution ; and
an insoluble matter remained of a fchocolate colour*.

Tungsten afforded a deep orange sublimate, which, when tungsten,
decomposed by water, afforded muriatic acid, and the yel-
low oxide of tungsten.

Till afforded Libavius's liquor, which gave a muriate by tint,
the action of water containing the oxide of tin, at the maxi-
mum of oxidation.

Silver and lead produced horn-silver and horn-lead, and silver lead, and
bismuth, butter of bismuth. The absorption of oxhnuriatic ^'^"^"*^' ^
gas was m the tollowing proportions tor two grams ot each gas absorbed,
of the metals; for arsenic 3*6 cubical inches, for antimony
• 3*1, for tellurium 2*4, for mercury I'OSf, for zinc 3*2, for
iron 5*8, for tin 4, for bismuth 1'5, for copper 3*4, for lead
'9; for silver, the absorption of volume was 0*9, and the in-
crease of weight of the silver was equivalent to 0*6 of a
grain}. ^-

In acting upon metallic oxides by oximuriatic gas, I Action of oxi-
found that those of lead, silver, tin, copper, antimony, bis- ^tdcs^^***^^
muth, and tellurium, were decomposed in a heat below
redness, but the oxides of the volatile metals more readily

♦ When muriate of manganese is made by solution of its oxide inmu- Effect of ox-
riatic acid, a neutral combination is obtained, but this is decomposed by ^de of manga-
heat ; muriatic gas flies off, and brown oxide of mangginese remains. In "^^® on mun-
this respect manganese appears as a Jink between the ancient metals and
the newly discovered ones. Its muriate is decomposed like that of mag-
nesia ; and its oxide is tlie only one amongst those long known, as far as
xny experiments have gone, wnich neutralizes the acid energy of muriatic
i»cid gas, so as to present it in solution from affecting vegetable blues.

t The gas in these experiments was not freed from aqueous va-
pour, and as stopcoks of brass were used, a little gas might have been
absorbed by the surface of this metal, so that the processes offer only ap-
proximations to the composition of tbeoximuridtes. The processes on
lead, tellurium, iron, antimony, copper, tin, mercury, and arsenic, were
carried on in three successive days, during which the height of the mer-
cury in the barometer varied from 30'26 inches to 30-15, and the height
of that in the thermometer from 63-5 to 61 Fahrenheit.

The experiment on sil-^jer ^sls made at the temperature of 52 Fal)ren<>
heit, and under a pressure equal to that of 29*9 inches.

X This agrees nearly with another experiment made by my brother, Mr,
John Davy, in which 12 grains of silver increased to 15*9 during their '

conversion into horn-silver. ;^ ^ . '''Ifflp

Q5*^ than

228 COMBINATIONS O^ OXlMUJlIATIC GA8 AND OXtGEN.

than those of the fixed otles. The oxides of cobalt and
nickel were scarcely acted upon at a dull red heat. The
red oxide of iron was not affected at a strong red heat, while
the black oxide was rapidly decomposed at a much lower
temperature; arsenical acid underwent no change at the
greatest heat that could be given it in the glass retort,
while the white oxide readily decomposed,
Oxigen given ' In cases where oxigen was given off, it was found exactly
the"metal\b- *^^ same in quantity as that which had been absorbed by
snbed. the metal. Thus 2 grains of red oxide of mercury ab-

sorbed 0*9 of a cubical inch of oximuriatic gas, and af-
forded 0*45 of oxigen*. Two grains of dark olive oxide»
from calomel decomposed by potash, absorbed about 0*94
of oximuriatic gas, and afforded 0*24 of oxigen, and corro-
sive sublimate was produced in both cases.

Analysis of • I have made two analyses of corrosive s^Ublimate 'and'Calonjeij'tSfitti'

corrosive sub- considerable care. 1 decomposed 100 grains of corrosive sublimate i>y
imate am o 90 grains of hydrat of potash. This aflorded 79*5 grains of orange co-"
loured oxide of mercury, 40 grains of which afforded 9-15 cubical iiiche*ofi
oxigen gas; the muriate of silver foimed from the 100 grains was 102^^..
100 grains of calomel, decomposed by 90 grains of potash, afForded^S2
grains of olive coloured oxide of mercury, of which 40 grains gave by de-
composition by heat 4'8 cubical inches of oxigen. The quantity of
horrx-silver form«d from the 100 grains was 58-75 grains.

In the second analysis, the quantity of oxide obtained from corrosive
sublimate was 78-7; the quantity of muriate of silver formed was 103.- 4.^-
the oxide produced frorh calomel weighed 83 grains ; the Jiorn-silver..
formed was 57^ grains. 1 am inclined to put most confidence in the lasti^
iinalyses 5 but the tenor of both is to show, that the quantity of oximu-
riatic gas in corrosive sublimate is exactly double that in calomel, aid-
that the orange oxide contains twice as much oxigen as the black, the
mercury being considered as the same in all. The olive colour of the ox-
ide formed from calomel is owing to a slight admixture of orange oxide,
formed by the oxigen of (he water used in precipitationj the tint I find is
almost black, when a boiling solution of potash is used; and trituration
with- a little orange oxide brings the tint to olive. It has been stated, that
the olive oxide thrown down from calomel by potash is a submuriate ;
but I have never been able to find a vestige of muriatic acid in it when
well washed. It is not easy to obtain peifect jirecision in analyses of the
oxides of mercury ; water adheres to the oxides, which cannot be en-
tirely driven off without the expulsion of some oxigen* In all my expe-
riments, though the oxides had been heated to a temperature above 212,
a little dew collected in the neck of the retort^ so that the 40 grains must
have been overrated.

In

rOM3INATI0KS OF OXIMURIATIC CAS AND OXIGEN, 2§^9

In the decomposition of the white oxide of zinc, oxigen O'^^^®*'""*^*
was expelled exactly equal to half the volume of the oximu- nic.
riatic acid absorbed. In the case of the decomposition of
the black oxide of iron, and the white oxide of arsenic, the
changes that occurred were of a very beautiful kind ; no ox-
igen was given off in either case, but butter of arsenic, and
arsenical acid formed in one instance, and the ferruginous
sublimate, and red oxide of iron in the other.

Two grains of white oxide of arsenic absorbed 0*8 of oxi-
muriatic gas*.

I doubt not that the same phenomena will be found to
occur in other instances, in which the metal has compara-f
tively a slight attraction only for oximuriatic gas, and when
it is susceptible of different degrees of oxidation, and in
which the peroxide is used.

The only instance in which I tried to decompose a com- Oxide «f tin.

mon metallic oxide, by muriatic acid, was in that of the

fawn coloured oxide of tin; a compound of water and Li-

bavius*s liquor separated.

From the proportions which may be g-ained in consider^ ^"^ P^""* ^^
1 , ,. • • . , . 1 , 1 i/v metal com-

ing the volumes of oximuriatic gas absorbed by the dilter- bines with

ent metals, in their relations to the quantity of oxieen which *"*^» ^^°> °^
would be required to convert them into oxides, it would ap- muriatic gus.
pear, that in the experiments to which I have referred,
cither one, two, or three proportions of oximuriatic gas
combine with one of metal, and consequently, from the com-
position of the muriates, it will be easy to obtain the num-
bers representing the proportions in which these metals
may be conceived to enter into other compoundaf.

* A singular iustance of the tendency of the oxide of nrsenic to be-
come arsenical acid occurs in its action on fused hydrat of potash, the
water in the hydrat is rapidly decomposed, and arseniui*etted hidrogen
erolvcd, and arseniate of potash formed.

•f From the experiments detailed in the note in the opposite page, it
would appear that the number representing the proportion in .which
mercury combines must be about 200. That of silver, as would ap-
pear from the results, page 227, about 100. The numbers of other me-
tals may be learnt frem the data in the same page, but, from what has
been stated, these data cannot be considered as very correct.

5. General

230 CO^fBlNATfON8 OF OXIMURIATIC GAS AKD OXIGEN.

5v General Conclusions and Observations, illustrated hy^ jE^jpw
paiiments.

Former infer- AH the conclusions, which I ventured to draw in my last

ences confirm- communication to the Society, will, I trust, be found to be

cot^ftrrned by the whole series of these new inquiries.

Oximuriatic Gxfmurlatic sfas cbmbirtes with inflammable bodies, to
gas combines „ • i i • t , . , . .

with inflam- iO\m simple binary compounds; and in these cases, when it

niable bodies, acts upon oxides, it erther produces the expulsion of their

oxigen, or causes it to enter into new combinations.

The oxigen If it be said, that the ttxigeti arisres frOni the decomposi-

not from its de- ^. r. ^i • • ^- V i " r ,i • i

composition, ^^^" ^^ ^"^ oxiinunatic gas, and not from the oxides; it

may be asked, why it is always the quantity contained in
the oxide ; and why in some cases, as those of the peroxides
of potassium and sodium, it bears no'relation to; the quan-
■ tity of gas. • ; - ,

Noacid matter If there existed any acid matter in 05timut(a1ic gas, com.>
bined with oxigen, it ought to be exhibited in the fluid
compound of one proportion of phosphorus, and two of
oximuriatic gas; for this, on such an assumption, should
consist of muriatic acid (on the old hypothesis, free from
water) and phosphorous acid ^ but this substance has no
effect on litmus paper, and doe^ not act, under common cir-
cumstances, on fixed alkaline bases, such as dry lime or
magnesia. Oximuriatic gas, like oxigen, must be combined
in large quantity with peculiar inflammable matter, to form
acid matter. In its union with hidrogen, it instantly reddens
the driest litmus paper, though a gaseous body. Contrary
*. to acids, it expels oxigen from protoxides, ^qd combine^
with peroxides.
Decomposi-'' When potassium is burnt in oximuriatic gas, a dry com-
tion of potash p^ynd jg obtained. If potassium combined with oxigen is
employed, the whole of the oxigen is expelled, and the same
compound formed. It is contrary to sound logic tasay, that
this exact quantity of oxigen is given off from a body not
known to be compound, when we are certain of its existence
in another; and all the cases are parallel.
Production of An argument in favour of the existence of oxigen in oxi-

oxirnariatic muriatic gas may be derived by some persons from the cir-
gdsfrommu- ° n- o -ii • p •• -j

riatic & oxide cumstances of its formation, by the action oj muriatic acia
of manganese. * 01^

C0M8INATI0NS OF OtlMURIATIC GAS AND OXIGEN.

m

OB peroxides, or on n^peroximunate of potash ; but a mi-
nute investigation of the subject will, 1 doubt not, show,
that the phenomena of this action are entirely consistent
with the views 1 have brought forward. By heating mu-
riatic acid gas in contact with dry peroxide of nianganejse,
water I found was rapidly formed, and oximuriatic gas pro-
duced, and the peroxide rendered brown. Now as muriatic
acid gas is known to consist of oximuriatic gas and hidro-
gen, there is no simple explanation of the result, except by
saying, that the hidrogen of the muriatic acid combined
with oxigen from the peroxide to produce watei*..

Scheele explained the bleaching powiers of the oxiiburi- its bleaching.
atic gas by supposing, that it destroyed colours by combin- ®^*^^* ' .^
ing with phlogiston. Berthollet considered it as acting by <iu,aou

Supplying oxigen. I have made an experiment, which seems ,ofri jt^U

to prove, that the pure gas is incapable of altering vegetable ; itl^noije

colours; and that its operation in bleaching depends en- owing to the
tirely upon its property of decomposing water, and liberating ^f^T]J.°^^''°^
its oxigen.

I filled a glass globe, containing dry powdered muriate Litmus papier

of lime, with oximuriatic eas. I introduced some dry paper '"'t affected bj

. . . J r r dry oximurt-

tmged with htmus, that had been just heated, into another atic gas,

globe containing dry muriate of lime ; after some time this

globe was exhausted, and then connected with the elobe :«Ti<ffTtot>

contammg the oximuriatic gas, and by an appropriate set -^uomTioa

of stopcocks, the paper was exposed to the action of the

gas. No change of colour took place, and after two day^

there was scarcely a perceptible alteration.

Some similar paper dried, introduced into gas that had, whitened by
not been exposed to muriate of lime, was instantly repdeced ™^'s*-
white*. •". ' • "^ - ^^ '^^P

'■■■.'... -■^u9[

Paper that had not been previously dried, brought into Moist paper »
contact with dried eas» underwent the same chane:e. but *^^^"^®** "'°'"®

, , ^ '° r - slowly.

more slowly.

The hyperoximuriates seem to owe their bleaching powers Hyperoximu-
entirely to their loosely, combined oxigen ; ther^ is a gtrong J"^'*^ act by

* The hst experiments were made in the laboratory of the Dublin
Society; most of the preceding ones in the laboratory of the Royal In-
stitution j and 1 have been permitted to r«fer to them by the Managers
of that useful public establishment.

y tendency

S3? CpMBINlTIONS Of OXIMURIATIC GAS AND OXIGEK.

loosely com* tendency iu the metal of those ia common use, to form
bmedoxigen. simple combinations with oximuriatic gas, and the oxigen is

easily expelled or attracted from them.
Oximuriatic H ^s generally stated in chemical books, that oximuriatic

gis not con- ^ras is capable of beingj condensed and crystallised at a low

<lensed and ^ _ , r ^ - i * •

crvstallijed temperature ; 1 have found by several experiments, that
by cold. this is not the case. The solution of oximuriatic gas in

water freezes more readily than pure water, but the pure
gas dried by muriate of lime undergoes no change whatever,
at a temperature of 40 belo>w o° of Fahrenheit. The mis-
take seems to have arisen from the exposure of the gas to
cold in bottles containing moisture;
Poractum, I attempted to decompose boracic and phosphoric acids

phosphorus, j^y oximuriatic gas, but without success: from which it
iron, and arse- .*' , , , , i . ■ i^ ■, • ,

nic, attract ox- seems probable, that the attractions ot boracmm and

igen more phosphorus for oxigen are strong-er than for oximuriatic gas.

strongly; . , ^. , . n ^ , ' j j . •, , • V'

And from the experiments 1 have already detailed, iron and

arsenic are analogous in this respect^ and probably some
other metals. *

somfi other Potassium, sodium, calciunti, strontium, bar iiitp, zinc,

substances oxi- mercury, tin, lead, and probably silver, antimony, and gold,
^ ' seem to have a stronger attraction for oximuriatic gas than
for oxi gen.
Combinations ^ ^^^^ ^* ^^^ ^^^" able to make very few experiments on
of oximuriatic the combinations of the oximuriatic compounds with each
compounds, other, or with oxides. The liquor from arseuic, and that
from tin, mix, producing an increase of teraperattire^ and
the phosphuretted, and the sulphuretted liquors unite with
each other, and with the liquor of Libavius, but without any
remarkable phenomena.
Oximuriates of I heated lime gently in a green glass tube, and passed
phosphorus the phosphoric sublimate, the saturated oximuriate of phos-
phorus through it, in vapour; there was a violent action
with the production of heat and light, and a gray fused
mass was formed, which afforded, by the action of water,
muriate and phosphate of lime,

I introduced some vapour from the heated phosphoric

sublimate into an exhausted retort containing dry paper

tinged with litmus; the colour slowly changed to pale red.

Indications of This fact seems in favoar of the idea, that the substance is

a^

COMPINATIONS OF OXIMURIATIC GAS AND OXIGEN. 123S

an acid; but as some minute quantity of aqueous vapour its aciditj^,
might have been present in the receiver, th^ experim'^rit
cannot be regarded as decisive; tbe strength of its attraction '
for ammonia is perhaps likewise in favour of this opinion.
All the oximuriates that I have tried, iudeed, form triple
compounds with this alkali ; but the phosphorus is expellecl;^
by a gentle heat from the other compounds of oximuriatjd'
gas and phosphorus with ammonia, and the substance re-
maining in combination is the phosphoric sublimate.

6, Some Reflections on the Nomenclature of the OximiiTi^
atic Compounds*

To call a body which is not known to contain oxigen, and Nomenclature
which cannot contain muriatic acid, oxamuriatic acid, jt, ^^*^*^"^^^^^**^
contrary to the principles of that nomenclature in which it
is adopted ; and an alteration of it seems necessary to assist
the progress of discussion, and to diffiise just ideas on the
subject. If the great discoverer of this substance had signi-
fied it by any simple name, it would have been proper td'
have recurred to it; but dephlogisticated marine acid is a '
term, which can hardly be adopted in the present advanced
sera of the science. ' ' '

After consulting some of the most eminent chertilcsil phi-
losophers in this country, it has been judged most proper
to suggest a name founded upon one of its obvious and cha-
racteristic properties — its colour, and to call it cA/ome, of Chlorine, or
chloric gns*. chloric gas.

Should it hereaften be discovered to be a compound, and
even to contain oxigen,' this^ name can imply no errouf, ami'-
cannot necessarily require a change. > t

Most of the salts, which have been called muriates, are not Salts impro-

known tp contain any muriatic acid, or any oxisren. Thus P^'"'>' ^^'l^*

. , -. 11 1 • ■ \ muriates,

Ljbavjus s hqupr, though converted into a muriate by water,

contains only tin and oximuriatic gas, and horn-silver seems

incapable of being conyerted into a true muriate.

1 venture to propose for the compounds of oximuriatic Compounds o^"

gas and inflammable matter the name of their bases, with f^'^'munatic

the termination awe. Thu« argentane may signify horn-

♦ From X^*'f°^»

silver

£3^ COMBINATIONS OF OXIMURIATIC GAS AND OXIGEI,,

silver; st&nnane, Libavius*s liquor; antimonane, butter of
antimony ; sulphurane. Dr. Thomson's sulphuretted liquor;
and so on for the rest.

In cases when the. proportion is one quantity of oximuri-
atic gas and one of inflammable matter, this nomenclature
will be competent to express the class to which the body
belongs, and its constitution. In cases when two or more
proportions of inflammable matter combine with one of
gas; or two or more of gasj with one of inflammable mat-
ter; it may be convenient to signify the proportions by|affix«
ing vowels before the name, when the inflammable matter
predonnnates, and after the name, when the gas is in ex-
cess; and in the order of the alphabet, a signifying two, f,
three, i four, and so on.
Muriates, The name muriatic acid, as a^pplied to the compound of

hidrogen and oximuriatic gas, there seems to be no reason
for altering. And the compounds of this body with oxides
should be characterised in the usual manner, and as the
other neutral salts.

iThus muriate of ammonia and muriate of magnesia are
perfectly correct expressions.

I shall not dwell any longer at present upon thisi subject*
--What 1 have advanced, I advance merely as suggestion,
and principally for the purpose. pf calling the attention of
philosophers %o it*, ^s chemistiy improves, many other

alterations

* It maybe eottcei^d, tllat a name mjiy be found for oximuriatic gas
in some mt>di|ication of its present appeUation,^vhicb may harmonize with
the uew ritw3,and which may yet signify its relation to the muriatic acid,
Ruch as demuriatic gas/or oximuric gas 5 but in this case it would be ne-
cessavy to call the muriatic acid, hydrogenated muriatic acid, or hydro-
muriatic aeid J ana tbe'Ealts which contain it hydrogenated muriates or
hydromuriatcs ; atid on such a plan, the compounds of oximuriatic gas
miJat be catted demuiiates or oxhnuriates, which I coriceive would create
' more complexity and difficulty in unfolding just ideas on this depart-
ment of cheiuical knowledge, than the methods which I have ventured
to propose. It may however be right, considering the infant state of
♦he investigation, to sus])end fqr a time the adoption of any new terms
for these compounds. It is possible, that oximuriatic gas may be com-
pound^ and that this body and oxigeii may contain some common prin-
ciple j but at present we have no more right to say that oximuriatic
gas potttains oxigen, than to say that tin contains hidrogen j and names

should

COMBINATIONS OF OXlMURlAT^li OAS AND OXIOEN. £3^

alterations will be necessary; and.\tisto be hope<1, tha^,
whenever they take place, they will be madle indebendeiif

should express things, and not opinions ; and till a liody is decom-
posed, it should be consi('ered as simple.

In the last nnnibcr of Mr. Nicholson's Journal, which appeared
, February 1st, while this sheet was correcting for the press, I have seen
an ingenious paper, by Mr. Murray, of l^diiiburgh, in which he has
attempted to show, that oximuiiatic g^as contains oxigen. His methods Supposed 4e^
are, by detonating oximuiiatic gas in excess with a mixture of hi- composition «f
drogen, and gaseous oxide of carbon, when he supposes carbonic acid oximuriatjc
is formed; and by mixing oJiimuviafic gas in excess with sulphuretted ^^''^"I'l**^"-^*
hidrogen, when he stippofte/! siilphuric acid, or snlplmreoiis acid is
formed. In some experiments, in which my brother, Mr. John Davy,
was so good as to cooperate, made over boiled mercury, we found,
that 7 parts of hidrogen, 9 parts of gaseous oxide of carbon, and 20
parts of oximuriatic gas, exploded h'y the electric spark, diminished «'>33'-l04''i'^
to about 30 measures ; and calonicl was formed on the sides of the tube.
On adding di-y ammonia jn excess, «nd exposing the remainder to
water, a gas remained, which equalled more than 9 measures, and which,
was gaseous pxide of carbon, with no move impurity than might be
expected from the air in thegasses, and the nitrogen expelled from th©
ammonia ; so that the oxigcn in Mr. Murray's carbonic acid, it seems,
was obtained from tcatery or from the carbonic oxide. Sulphuiettedf
hidrogen, added, over dry mercury, to oximuriatic gas in excess, irf-
flamcd in two or three experiments; muriatic acid gas, containing;
the vapour of oximuriate of sulphur, was formed, which, when neutral-
ized by ammonia, gave muriate of ammonia, andacop;ibiuation.-Qf:um-.
monia and oximuriate of sulphur.

When a mixture of oximuriatic gas in excess, and sulphuretted hidro-
gen, was suffered to pa;xs into the atmosphere, the smell was thatof
oximuriate of sulphur ; there was not the slightest indication of tl|e
presence of any sulphuric or sulphureous acid. If Mr. Murray hu4
used ammonia, instead of water, for analyzing his i-esults, I do not
think he would have concluded, that oximuriatic gas is capable of
decomposition by such methods.

I shall not, at present, enter upon a detail of other expcriracnlB,
which 1 have made on this subject, in cooperation with my brother, as
it is his i-.itention to refer to them, in an answer to Mr. Murray's paper.

I «hall conclude, by saying^ that this ingenious chemist has mistaken
my views, in supposing them hypothetical J I merely state what I have
seen, and what I have found. There may be oxigen in oximuriatic
gas; but I can find none. I repeated Mr. Murray's experiments ^vith
great interest ; and their results, when Tto^er is excluded, entirely con-
firm all my ideas on the subject, and afford no support to the hypotheti-
cal ideas, which he has laboured so zealously to defend.

of

236

SCIENTIFIC NEWS.

of all speculative views, that new names will be derived from
some simple and invariable property, apd that mere arbitrary
designations will be employed, to signify the class to which
compounds or simple bodies belong.

I'V.':.

Iceland crystal.

Ember-goose.

Qualities of
SQund.

SaENTlFIC NEWS.
Wernerian Natural History Society,

T the meeting of this Society on the 27th of April,
Professor Jameson read a paper concerning the geognostic
relations of the Iceland doubly-refracting crystal. The
secretary communicated an account of the habits of the co-^
lymbus iramer, or ember-goose, by Dr. Edmonston of
Lerwick. And Dr. Gordon read an interesting paper, con-
sisting of observations and experiments on the qualities of
sensation of sound ; on the different modes in which sono-
rous vibrations are communicated to the auditory nerve ; on
the ideas of the distance, and of the angular position of
sounding bodies with respect to the ear, which are asso*
ciated, by experience, with the different qualities of sounds;
and on some of the more remarkable differences in the sense
of hearings both original and accidental, which are occa-
sionally observed among individuals, and, iii particular,' itfft*
the musical ear, -?.':

Albnmen of
seeds affords
nutriment to
the plant.

J^eport of the Proceedings of the Mathematical and Physical
Class of th^ French Institute, continued from p. 159.

Mr, Mirbel has continued his researches into the physio-
logy of plants. Hitherto it had been acknowledged indeed,
that the albumen of seeds commonly served to nourish the
young plant after germination ; but this opinion required
the support of positive observations, and Mr. Mirbel ap-
pears to have removed all doubts respecting it by an expe-
riment as simple as ingenious. The embryo in the seed of
the onion bends as it unfolds itself, so as to form an elbow
that rises out of the ground, while the plumula and radicle
jemain concealed in it. If at this stage of vegetation 9.

mark

ICIENTIFIC NEVJ^. gST"

mjirk of any kind be made at equal heights on the'lWo
branches of the geroie, the mark nearest the radicle will
rise alone, if the plant received no aliment but from the
juices of the Earth ; on the contrary, if it were nourished
solely by the albumen of the seed, the mark on the pla-
mule would rise above the other: and lastly, the mar&s
would rise pretty equally, if both the ground and the seed
concurred in the developement of the germe. It is the latter
phenomenon that takes place; and it ceases when the albu-
men is eniirelj' absorbed : the young plant has then strength
enough, to derive from the ground or the atmosphere the ,
nourishment it thenceforward requires.

This paper is acconrtpanied with interesting observations Germinatioa
on the germination of asparagus, and on the manner in °f ^'P*'^"^*
which the leaves of this plant, at first ensheathed like all
those of the monocotyledons, become, by the grov/th of
the stalk, lateral and opposite, and afterward lateral and
alternate.

In another paper Mr. Mirbel has examined the germina- and of thewa.
tion of the nelumbium. Botanists were not unanimous re- ^^^ "^y*
specting the class, to which this plant should be referred, or
the nature of the two fleshy lobes, from between which it
springs. Some, observing no radicles developed in the ger*
mination of this plant, suppose it to be destitute of them :
some consider these lobes as roots ; others as peculiar or-
gans analogous to the vitellus, Mr. M. has endeavoured to
remove these doubts by his dissections. In the first place
he finds in the nelumbium all the characters of a plant
with more than one cotyledon ; he next finds in the lobes
vessels analogous to those of cotyledons; and at the junc-
ture of the lobes he observes other vessels, uniting in the
same manner as those that are characttiristic of the radicles
in embryos furnished with them. Hence he concludes, that
the water lily does not differ essentially from the other plants
of its class.

Mr. Correa, while he agrees with Mr. M. in considering The lobss of
the nelumbium as a dicotyledon, differs from him on the ^^*,^^®'^1^^
nature of the lobes. He thinks, with Gaertner, that they the vitellus.
have a great analogy to the vitellus, and he compares them
with the fleshy tubercles of the roots of orchis. Plants he

observes

^38

Germination
«f grasses.

Amphibious
tDammaliar*

ftCJEKTlIXC K£W5l.

observes hav^e 3 doui^le . ori^anization, relating, en the c^fe
hand, to the earth, in which thej spread thtir roots; on the
other, to the air, in Ahicfi their leaves are expanded; The
roots are destiued to the ascending vegetation ; the leaves,
to the descending ; and it is at the point where these two
•ysteras unite, that the cotyledons are usually placed. But
the lobes of the nelumbium are at the lowest part of the
plant, and consequently belong to the roots. The example
of many other plants destitute of cotyledons shows, that
they are not essential to vegetation ; and that the characters
derived from them to arrange thfe vegetable kingdom in
three divisions are insufficient^ and should be replaced by
those arising from the direction of the vessels and medullary
radii.

Mr. Poiteau has examined the germination of grasses.
The part of the seed, wiiich ought to be considered as the
cotyledon, is yet questioned among botanists. Mr. P., ob-
serving that the scutum, which Giiertner took for a vitellus,
and Mr. Richard for the body of the radicle, was placed at
the point where the plumula and radicle separate, deems
this a true cotyledon. Mr, P. has observed too, that, the
moment when the' radicle of a grass is unfolded, it assumes
the iigure of a cone, and represents the taproot of other
plants ; but as soon as the lateral roots have acquired a cer-
tain growth, this cone is obliterated, so that no plant of this
family has a taproot. And as Mr. P. has made the same
observation on several other monocotyledons, this substitu-
tion of numerous secondary roots for ope principal root
takes place,- because each bundle of fibres of the monocoty-
ledons has its peculiar root. . . >

The researches of Mr. Cuvier cQi^cerning fossil animals
have commonly led him to discussion^ respecting the spe-
cies admitted by naturalists, tending generally to the ad-
vancemfcut of the science of zoology. Thus in considering
the organization of the amphibious mammalise, he has been
led to separate from the seals and morses, the Indian wall-
rus, the manatees, and the species described by Steller.
These three genera form one family, distinguished by the
absence of the posterior extremities, and by herbivorous
teeth.

In

SCIENTIFIC NEWS. 2'39

Id another paper, on the genus felis, he gives the osteolo- Feline genus,
gical characters of the head in the principal species; and
has made known a species not distinguished by modern
naturalists. To this he has given the name of leopard. Leopard,
which had become synonimous with panther, for want of
being able to apply it with precision. It dijQTers from the
latter in being of a smaller size, and having a greater num-
ber of spots,

Mr. Geoffroy long ago made a particular division, under Classification
the name of ateles, of the apes without thumbs, which had °^^P^»
been confounded with the sapajous, from the prehensile
tail common to both. He has now added two new species Two new spc-
to those he had already made known, and given figures and ^^^*
descriptions of them. One of them, which he names aracb-
noides, had been merely mentioned by Edwards and
Brown. The other, which he terms encadree is altogetber
new. It is black, with white hairs round the face.

The same gentleman has described two birds; one im- OmUhoIogy.
perfectly known, the other new. The latter has some re- ^

semblance both to the corvus nudus and the c. calvus ; but
there are sufficient differences between them to form three dis-
tinct genera, under the names of cephalopterus for the new
species, gymnoderus for the c. nudus, and gymnocephalus
for the c. calvus.

The cephalopterus is black, with a very high crest, which Cephalopte.
falls forward on the beak, and a kind of dewlap also covered ^^^'
vith feathers. Each of these is of a metallic violet colour.

The other bird, which had been imperfectly described by Microdacty-
Marcgrave under the name of cariama, Mr. G. had consi-
dered from his description as approaching to the trum-
peter; but now he has seen it in the Museum of Natural
History he classes it as a separate genus under the name of
microdactylus.

The tortoises have furnished Mr. G. with the subject of Tortoises,
another interesting paper. Having seen, while in Egypt,
the tortoise of the Nile, mentioned by Forskaol, he was led
to form a particular genus of all those, which like it have
the extremities of the ribs separate, and a soft shell. He
names it trionix, and has added to it severa'l new species.

Mr. Brougniart, in his elegant general treatise on reptiles, * ,

had

240

Monography
of toiiui&es.

letkyology.

Respiration of
tb.e ctocudiie.

SCIENTIFIC NEWS.

had classed these with his emydes ; noticing at the s^ame
time the characters, that distinguish them from all the
other species, the shell of which is complete and hard. The
large softsbelled tortoise of Bartram Mr. G, places in the
genus Chelys of Dumeril.

Twenty years agt) scarcely thirty species of tortoises were
known, but nearly twice as many are accurately described
by Mr. Sweiger in his general monography of tortoises. la
this wor1v a copious list of syaonimes is given, and it is il-
lustrated with figures carefully engraved.

The class of fishes too has been enriched with many new-
species. Mr. Risseau and Mr. Delaroche have communi-
cated the observations they made on this subject, the for-
mer in the Gulf of Nice, the latter in the sea round the
Balearic Islands. It has been supposed, that fishes had
their peculiar climates, but Mr. R. has found in the Medi-
terranean fishes considered as peculiar to the East Indies,
and others known only in the northern seas. Mr. Dela-
roche made some interesting observations on the depth at
which different fishes habitually live, the manner of catching
them, and their airbladders.

Notwithstanding the difficulty of physiological experi-
ments, and the nicety required in them, Mr. von Humboldt
made many during his dangerous and toilsome travels. He
has communicatt'd his experiments on the respiration of
the sharpnosed crocodile of America. He found, that,
notwithstanding the volume of its bronchiae, and the struc-
ture of its pulmonary cells, it suffers greatly without a sup-
ply of fresh air; its breathing is very slow ; and a young
one a foot long deprived the air of scarcely 12 cubic inches
of oxigenin an hour and forty tbvee minutes.

To he concluded in our next*

An accident has rendered us unable to insert our usual Me*
teorohgicci Journal this month*

JOURNAL

OF

NATURAL PHILOSOPHY, CHEMISTRY,

AND

THE ARTS.

AUGUST, 1811.

ARTICLE I.

On the Motion of Rockets both in Nonresisting and Resisting
Mediums, By W, Moore, Esq.

(Continued from Vol. XXVIII, p. I69J

To Mr. W. NICHOLSON.
SIR,

JL HE following is a farther extension of my essay con-

cerninj*' the motion of rockets in different mediums; which,

if worthy acceptance, is quite at your service. The last two

propositions are given as preparatory to my next inquiry,

which is that of the several effecis of the wind upon the first

motion of these machines, when it is blowing- in any given

direction and velocity ; which I will communicate to you as

soon as time will allow me properly to prepare a paper of

them.

From the results of the propositions that here follow, Curiott' fact«

some very curious and important facts are ascertained; as ^sctrtaned ih

,,"'.■' the foilowiaj

that the motion ot a rocket can never become uniform propoiitioni,

throughout the time of its burning under any law of resist-

ince whatever; that bodies projected into resisting me-

Vol, XXIX, No. 134,— -Aug. 18U, R dimms

SI4.2 THEORY OP THE HOTlOvV OF ROCKETS. '

dlums cannot, independent of gravity, describe certain
finite spaces but in infipite times, let the velocity of pro-
jection be what it may, great or small ; the ratio of the re-
sistance of a sphere to that of its circumsciibing cylinder,
when this moves in a direction perpendicular to its axis;
Itnd many other very curious particulars, as the person who
shall read this paper will fmd. The investigations of the re-
sistance to cylinders moving in fluids in directions diiferent
from that of their axes are new, as far as 1 know. No work,
that I am acquainted with, contains a solution to this pro-
blem generally, but merely of the common particular case,
where the solid is supposed to move in the direction of its axis ;
and perhaps the flight of rockets is one out of but very few
cases in which the subject is at all applicable.

With thanks for the attention which you have hitherto
paid to my communications, and respect for that impar-
tiality and ability, with which your Journal is conducted.

I am. Sir,

Your most ebedient servant,
IU>i/ah Academy; ~ " W. MOORE.

JunelSlU

^ ' t - Prop. 6.

The motion To determine whether. the Motion of a Rocket ascending ver-
of a rocket can tically in the Atmosphere can ever become uniform : the law
uliform!'^**™* o/'r^5fs/awc€ being directly as the square of the velocity y as
before*

When the motion of a body becomes uniform, or the ve-
locity a maximum, the accelerative force is then nothing:

^ ^ {sned^ b^—Kv^) a , , , -

therefore puttms ' , To ' t"^ accelerative

^ ... ^ .{am — ctj.b*

force (see ..the last Prop.) — o, and reducing the equation,

, , /sned^a — «w + c/\4 „,,
we have » r= A- t "■''"■ ^R ) * Whence it

ftppears^ that the velocity, and consequently the motion of
the rocket can never become equable ; being in terms of t
the time of its burning ; but will be greater and greater unto
the end of the time.^, when th^ velocity will continually dc*
crease till the whole is destroyed by the retardive force of
£ -U gravity.

gravity. And it is moreover evident, that the m6tiohof
a rocket can never become uniform Undtr Uriy law of resist*
ance whatever.

Pro?. 7.

All things rimaining as in the &th Proposition : to find thd Velocity and
Velocity and Space described by the Rocket, when it is in* ^P'**^® ^®*
Jiuencedonly by the impelling Force qfthe Composition and rocket fr©ni

the Resistance of the Medium. the impulse «f

its com position
and resictance

Here, gravity not acting, the acdeleriitive forc6 Of the °^ **^« °***^*

rocket at the end of the time I will be ■! — *» *~ ? M

[am-^cl] b*

as determined in I*rop. 5. Therefore <£» iS 2 gft H^

{sned^b*^Rv*),oaat , . . _

(7^"3T7)T6^ ~ (putting^ ziiagsned'b*,

k zz 2 a^ R, I :z amb*y and p = cb*) "J ~ ; and

v t 1

k__L"i ^ r-~;> thereof the fluent is ' "■ - ' « hyp. Idg.

-^ 2.(AA)*

\ k J t ft 'X

/A si = - -r-byp.l«g.(-- --Mwhicbjwhen

(t) -'' ^ ^ '^

« ::: 0 and I s 0, is o 2£ -.- — , hyp. log.*- : therefore the

P P

correct fluent is ->--^. hyp. log. 7-7^-7--^'*** iS -*J*

* J hyp. log — hyp. log. f^ -* A?^ ^ • ^yP-loj*

7 ► : tnd henc« by the natttfi ol logs.

\ ■ '

344 THEORY OP THE MOTION OF ROCKITS,

(t)'+-

Velocity and
space

scribed by a I -l-T-I i- v—v — ^ : or, putting

rock' '"' — I >' t -v 1

the

its composition

and resistance /' h \T [hk]'^

of the mcdi- ( -7- ) — j and J: — i — — w , we shaU have

um. \ k / P

J "^ ^ rr ; and by reducing this equa

j — V (^— P')""

ar

9

10

IV

. - ^iLjzlSLlLEJL- ; which, when t - a, \s V ^

' ^ w . w

i "^ '^ V ""^ F I tije velocity of the rocket when it just

ceases burning. Or, restoring the values of j, w, /, /i, &c.,

the velocity of the rocket in thiscase will Tbe expressed by

1 X

Aa^d {sneH)^ 4 agd {sne'R)x

rfj.^^y. ) (ami*) '* -[amb^-acb^) "^ )

- - ... - - J

4a.^d(^neR)^ AagdjsneB.)^

. cb - cb

(amb^) + [amb'^^acb'')

Now to determine what this velocity is, we must first find
the value of R for the given case of velocity b. Now under
the conditions, that the p-articles of the medium are perfectly
nonelastic, and that the medium is intuiitely comprestied
and affords no resistance to the motion of the rocket but what
arises from the inertia of its |f)articles, (which is the ground
of ourhypptheses concerning the law of resistance), we shall,
putting r for the radius of the rocket's base or of the head
of the rocket ;y=i the sine of the angle, which the slant
side of the head, (supposing it conical) makes with the axis;
p =z 3*14l6; S zr the specific gravity of the medium,
whichishereconsidered as the atmosphere; and ^ zz l6feet,

(omitting the tV) ^»ave R zz \__ Z-L- (investigated in

most woi[ks of fluxions and mechanics).

Let h zz \y in order to render the expression as simple as

pos'sible^

THEORY OF THE MOTION OF ROCKETS. 245

possible; and the angle, the sine of which is /, 30 degrees;
then /' =: • 5 or 4- (to rad,. 1); and taking the specific gravity
ofairat a medium, or S n 1 f , R will be found zz -0002343
ounces; which is the absolute resistance the rocket suffer*
when moving with a velocity of 1 foot per second. Hence
the expression above for v will become -------

4 rt^^c? (-0002343*71^) — ?-.{*0002S A3 sne)

1 c — i — e A

vtW c f

). /(am) — (a TO — >ac) \

v-ooc

0002343/

±l.li (-0002343 sne)' tl^^ (-0002343 sne)^

c c

(a m) ■\- (am — ac)

and substituting the values for a, c, d, &c., which are as fol«
low : namely,

s = 1000

n =z 230 ozs.

w zi 18 lbs. = 288 ozs.

c =: 10 lbs. zz l60 ozs.

m = w -{* c zz 448 ozs.

a. zz 3 sec.

-- ' g = 16 ft.

it IS V zr

e = *7854
6941-575 ( 1344 — 864

/ 1-95171 1-95171

1-95171 1-95171

1344 + 864

^mi^^pi^ = 2820-3a5feet: which is th'ere-
1814180

fore the greatest velocity the rocket can acquire, and which Velocity.

it does acquire at the end of its burning.

It is somewhat remarkable, that the whole resistance of

the air to the rocket, on the supposition that gravity does

not act, should so nearly approximate to the effect of this

force (considered as constant) when there is no consideration

of any resistance from the former ; the deviation causing no

more than (2896-9895 — 2820-325 = ) 76*6645 feet per

second

as f moRT OF THH: MOTION «p ^c^^Tf.

Velocity. second difference iu th? grwtest velocity of the rocket on
th*? »ide of gravity.

To 6nd the $pace described. By the theory of variable

motions^ s: ./ = ^^,/(^^^7y%^ =^^ -

and /' = ■— - . Whence x =: ^^ -^ ^- ,^.. ^.

- (by expanding ^^ ^ ^^ in a series) — i 4. 31

T T _ T T T_jr T T \

(w 4. 1
T
(w4- 1)/^

T T T

(2ti; + l)./*«' (3m? -f 1) Z^'*' {4u;+ l].^*«' ^ ^^

p pl"" V«^ -hi C2 U? + 1) /«>

2 to SttJ

T T

C i« '^ 1 w

■< f7 , ,, ■ 2(/-p<) /_L_ (^-po

^ (3ii;-f 1)/*^ (4W+ !)./'«' ^ >f )

the fluent corrected

{

pi Vw -f I

imottY OF THE MOTiaNF tti^ llC^CK^W* 24f

Iff
2 (/ — up)

Sec. j r = (when t =z a) j. \ a ^

(

^ w

2 w
1 (/ — ap) X (^ — fly)

tu+1 ]<iW'\-U.l^ '^ {3w + ij.l*"^ '

(3t» + 1) . /*'*' y ? V'^ + 1 2w+l

4- — , $z'\^i ? for the s^pace de«cribed by thef^

^ 3u; + 1 y 5

rocket at the end of the time /.

Now to determine how far the rocket wiU farther move
before its motion is wholly destroyed. Put a =: the velocity^
at the end of its burning = 2820*325 feet per second, and
V any variable velocity corresponding to the space x; w zz
weight of the rocket =: 448ozs., and R = '0002343 ounces^
the resistance of the medium to the rocket when moving
with a velocity of 1 foot, per second. Then R i>* will be the

R »*

resistance to velocity v, and the force by which the

rocket is retarded by the fluid. Hence 4- = r-rr = -^

. and X r: "^^ — rr • hyp. log. v ; and the fluent
2gR

. hyp. log. a. Which by substitution

2gR

efnumbersis = 305170'3 feet.

Hence it appears, that, after the burning of the rocket Space de-
ceases, it will move to a distariceof 305 170''3 feet, or nearly 58 *c"bed.
miles, before all its motion is destroyed, when it will remain
at rest in the medium ; there being no force to influence it
in any manner or direction whatever, and having no power
to create motion in itself.

As to the lime that the rocket would be in movingthrough Timeof mov-
this space, it -will be had as follows. The same substitution ing through it.
as above being retained; the general fluxional expression

for the time [t') namely will be found n

2^/ 2gRo*

248

THEORY OP THE MOTION OF ROCKETS.

»— 1

RtJ*

fluent of which is < ~

-J- (substituting for / as before) the

Now when t zz 0,v zz a,

1

2gliv
therefore the correct fluent of the time is ^ ~
1

2 g- R w

which, on v becoming nothing, will be infinite.

A projected
body cannot
lose all its mo-
tion ill any
finilQ time.

Resistance to

a cylinder
rnoving per-
pendicularly
through a
fluid.

2glla

So that it appears, that the rocket will not describe the
above space but in an infinite tiaae.

Supposes =: 1 foot; then ^ = - "^^ — 133-344 se-

2giia

conds or 2 min. 13 seconds. That is, the rocket will only-
have been in motion 2 min. 13 sec. after it has acquired the
greatest velocity from its burning before the celerity of its
motion will be reduced to 1 foot per second ; and yet, not-
withstanding this great annihilation of velocity in so short a
time, the remaining small part will not in any finite time
be destroyed, though we know the limit at which the rocket
would attain a state of quiescence.

And from the result here determined we conclude, that
into whatever medium a body is projected with any given
velocity, great or small, it will in no finite time lose all its
motion. So that, if the planetary bodies were moving in
a resisting medium, and gravity should suddenly be de-
stroyed ; the bodies would all pursue rectilinear paths (that
would be tangents to their orbits) to certain finite distances,
which would not be wholly described by them but in infi-
nite times.

Lemma I.

To determine the Resistance a Cylinder meets with in a Fluid
when moving in a Direction perpendicular to its Axis.

It is universally allowed, and indeed is evident, that the
resistance to a body moving through an infinite fluid at rest
(such as is here supposed) is the same in eflect as the force
of the fluid in motion with equal velocity on the body at
rest: therefore, as it will be somewhat more convenient tocon-
sider the fluid in motion, and the body quiescent, we shall
pursue the solution of the problem upon this hypothesis.

1HEORT O^ THE MOTIOM OF ROCKETS. 24,g|

Let A BCD (PI. VII, fig. Ijbethecylinder, andETF Resistance to *
any ^ection parallel to the base. Let a particle strike this sec- cylinder inoT-
..1 1 T-»rr, 1-1 L 'x.- insf perpendi-

tion at 1 u) the direction F 1 , ;jerpeudicuiar, by supposition, cularly

to 13D ; and draw T O to the cti.tre O : draw also the tan- through a *
gent T Q to the circle E T F or cylindec at T, upon which
let fall the perpendicular P Q, and let fall the perpendicular
QRupouTP.

Then, considering P T to represent the full force of a
particle of the fluid, P R will denote that part only, which
has eii'ect in raoving the cylinder in the direction PR,
For, on account of the obliquity of the surface of the solid,
the strcikeof the particle will also be oblique;- and therefore,
resolving T P intothe two forces PQand TQ, the forceTQ
only wii! be eftective, which, hi the direction P R, will be
as P R, or the sine of the angle P Q R, or P T Q } us is evi-
dent by considering PQ resolved into the two forces Q R,
R P ; whereof ihe former, being parallel to the cylinder, fia«
no effect in moving it in a peri)endlcular direction thereto.

Now by the nature of fluids, the force with which a
particle strikes a body perpendicularly is equal to the weight
of a line of such particles, the height of which is equal to
that which is due to the velocity of its motion, or through
which a body must full to acquire that velocity ; therefore,

calling n the density of the particles or fluid ; (where

» denotes the velocity, and ^ — 1 6 feet) will be the abso-
lute force of a particle moving with the velocify r. And
this is represented above by the line PT; therefore, since
rad. (1) : TP :: sin. Z P T Q (5) : P Q, the force, de-

X 2, ■ »■•■ -

noted by P Q will be ^^-^ , and that by PR*'"

4g 4g

Put SL zz X, LT z= y, and S T -= s;- also let Ti»
{— z) express the fluxion of the course S T; then, because
of the inclination of this line to the direction of the fluid,
the number of particles striking it will be diininished in
the ratio of T n to no, or of radius to the sine of the
angle oTw; consequently the fluxion of the force of
the fluid against ST, which would otherwise have beea

» will be

Now

||j|0 rSKORT OF THB MOTION OF ROCKETH.

Resistance to. ^^'^ ^ = t-^* + ^2)^ ; and y = (2 Tx - a«*)^' by the
cylinder moT- . r .» • » .i . r i* ■ — .r jic-

tng perpcndU Property of the circle; consequently j =:

thmugba x ^^

flttid. and a = (i* + j*)' z: -; (r being the rad.

(2rx — x*)«
of the dr. E S F). Also, by reason ol similar triangles,

OP LT y ^ ^. QP

^Tp- = -qTj; == — : whence s, being = ^rp » ^^"t

also be equal to -^ • Therefore by substitution -—

-^ / rj_ ^ a^ (2rx — ar*)^

r X WW*, -, p 1 • 1 ♦

' 1 "~ * [2 rx X -^ X x) ; of which the

{2rx — a:*)« 4^r

W V* ^3 T x"^ x^ \

fiuentis . ^ %' ( " / wanting no correction ; so

that when x = 2 r the fluent will be ^L^LZ ; which is the

^ effective force of the fluid on the senxicircumference
of a section of the cylinder parallel to the base. Conse-
quently -- — into the height of the cylinder (k) zz

' ^ will be the resistance, that the whole cylinder suf*

fers when it moves in a direction perpendicular to its axis
with the velocity v.

Cor, Because it is found, that a sphere, the radius of
which is r, moving in a fluid of the density n, with the velo-

V city V, is • — ; we shall have the resistance of the

sphere to the resistance of its circumscribing cylinder as

*Lf to , or as 1 to (where© r: 3*14 10);

the latter therefore being resisted more than the former by
about '69829 of the former. Whence, the resistance to a
sphere being given, the resistance to its circumscribing
cylinder will be had by multiplying the former by 1-69829.

(.EMMA

TBIORT OF THE HOTION OF ROCKCTI* f^

Lemma II.

To determine the same as in the last, when the Cylinder moves Resisttwe* %

in any Direction oblique to its Axis. * cylinder

^ > rtioving o©»

liquely.
Let T P (PI. VII, fig. 2) be the direction of the cylinder
moving in the fluid, or P T that of the fluid against the
cyHader. Let a particle strike the solid at T, at which
point draw the tangent T n to the section £ F T, which i»
parallel to the base C D: draw L T Q perp. to the diame-
ter V O S, which is at right angles to the axis X Y, and
P Q and Q R perp. to T Q and T P respectively. Then,
denoting the force of a particle of the fluid when in raotioji
by P T, and supposing this to be resolved into the twe
forces PQ, QT, the latter only, Q T, whicj) varies as the
sine of the angle T P Q, will have effect in moving the cj^^* ^
linder; which, in the direction V T, will be as R T, or the
sine of the angle T Q tl, or S P Q. Now the elective ferce
of a particle in the direction Q T has been shovyu in the

preceding lemma to be equal to — when the wb^

4 or

force of a particle is represented by Q 1': but in tlie case
before us, piittingy for the siye of the angle Q P T, or of
the angle of incidence of the irapingeisg fluid against tbe

. - ' ■ • • ^ wo'

solid, the efficacy of Q T will consequently be —

(where s zr sin. of the angle Q Tti) and therefore the effect
of a particle to move the cylinder in the direction PT will

be J^ ,

Put c iz sii). of the angle P T Q, the dosin. being/*
r — rad. of the base of the cylindef
a: zz G L
y = T L
Then, by reason of thesimilitiideof the triangles O LT,

Tn K,. we obviously obtain * zz — iz ■ '^ ■ , and

tli«

252 THEORY or TUB MOTION OF ROCKETS.

Resistance to the cosine of the angle K T n — — ; (radius being unity
a cylinder ♦ r

tnoTing ob- i„ jjIi ^,3ggg> j^^^^ ]ei z zz FT and x the fluxion of the
liquely. ^ i -r *

same, then the fluxion of the force of the fluid on F T

will be :z ^ multiplied by the sine of the angle

P Tn, whereof the angle PT n being composed of the two
angles P T Q, Q T n, the^atural sines and cosines of which
are represented above; its sine by trig, will be expressed by

^ +/ll'_Zl!!>i = llJ-il^lZlil^; also i

T X

zz -• . Therefore

* «* /'a ^

. sine angle P T w r:

n t)* 5*/ ' k

nvp"- r« — a* rx . ex 4- /(r« — J:«)^

^ , (r^-x*r-

4gr' L

the fluent of which is

which corrected will, in the ultimate case, where x i= r, be

which is therefore the cffeaive force of the fluid onthequadran-
talarch FTS. Hence Z^l!l . (c + s/) will be the force

on the semicircum. V F S; and -_'- (c + <lj ) the-

force on the whole semicylindric surface m Dwr B^;

or

THEORY OF THE MOTION OF ROCKETS. 253

or the resistance to the cylinder when moving in the fluid Resistance f
at rest, so far as relates to that surface. rooving ob-

To determine what fartlier resistance is opposed to the lil^ely.
cylinder by the fluid acting against the top As Br. Let us
suppose AV BT (fig. 3) to be the head of the cylinder, and a
particle striking it at T ; also let A B be a diameter of the
circle perp. to the axis, and draw T Q parallel to A B, and
P Q and Q E perp. to T Q and T P respectively. Then
P T being considered the representative of the full force of
a particle, and to be resolved into the two forces P Q, T Q;
the force T.Q, being parallel to the plane A B V, has no
effect in causing it to move; but only the force denoted by
P Q, which is as the sine (c) of the angle P T Q. There-
fore the effective force of a particle in this case will be

» a
■ : and that of the fluid on the whole circular plane

— (p being z: 3'14l6). Hence the whole resist-
ance to the cylinder is

Car, 1. When the angle T P Q (fig. 2) is 90% or the so-

lid moves in a direction perp. to its axis ; then ^^ becoming

1 ^nd c nothing, the resistance to the cylinder will be

«v' r h - .1.1^1
as determmed m the first lemma.

^^

Cor, 2. The resistance to the cylinder moving in the di-

rection T P estimated in the direction Q T is

nv'^J^r h

(c + 2^), being that arising only from the action of the
fluid upon the semisurface of the solid; that on the head or
top of the cylinder having no effect to move it inthis direction,
but in the direction of its axis.

For- an example to this proposition in numbers, when
the medium is supposed to be that of our atmosphere. Let
the angle T P Q (the sine of which is/) — 6o° ; and conse-
quently the angle PT Q (the sine of which is c) n 30%

Then

fiM

BEFECTlVt ALGORITHM Or IMAOl»ARY QtTAKTITItS^

Then we have C n

c r:

Let r rr

A =

K ^
n zz

nv*J>rh
Hence ^—^

ifoot

•865
•5

6 in. ^
1 ft.
3 ft.

16 ft, (omitting th« /-jth)
1 i

(^+2/) +

ne

Pr'

4ir

•OSt966s7 + -00187486 r: •03384173 ounces for there-
STstanceto a cylinder of the above dimensions, when moving
with the velocity of 1 foot per second. And therefore, as
the resistance to the same cylinder varies as the square of
the velocity, the resistjmce corresponding to any other ve-
locity will be had by multiplying the above by the velocity
(in £eet) squared.

A qnafJrattc
equation ap-
|»arently with
t^ree roots.

On the Defective Algorithm vf Imaginary Qvantities, In a
Letter from a Correspondent,

To Mr. NICHOLSON.

SIR,

aN a mathematical investigation, in which I was lately en-
gaged, I fell upon a very, singular anomaly in the theory of
equations, which is nothing Icss^ than a quadratic equaiiofi
havinLJC (at least to all appearance) three roots, all different
from each other; whereas, according to received principles,
it can have only two. As this is a very Orange deviation
from what has been hitherto considered as a wtll established
theory, 1 am induced to request the publication of it in your
Journal, in hopes that some of your mathematical corres-
pondents may undertake to explain the difficulty, and res-
cue the theory of equations, and the present algorithm of
imagina.ry quantities, from the danger to which such ano-
malies rauft necessarily expose theoi ; particularly as there

DEfSCTITA ALGORITHM Ot tMAGINART QUANTITIES* g54

»re some among us, who wish to cramp the power of ana-
lysis, by r<^jecting in that science every species of quantity
coming under an imaginary form. 1 think I can perceive
where the mystery lies ; but still I should be glad to see the '
opinion of more able analysts on this apparent incongruity;
if however no such should appear, I will, through the me-
dium of your Journal, publish tpy ideas on the subject.
The equation to which I have alluded is this :

X* ■\- X n 2

and the three roots of it are the following,

1st root X — 1
2d root X zz. — 2

i

3d root X zz

f/^^V-i^p/i

V— f

The two first of which evidently answer the conditions of
the equation, and with the third 1 proceed as follows.

X zz

f/ii

+ ^/{i—/-

And now in order that I may be certiin of my results, t "
multiply these quantities under.the radicals at full length,
as follows ; viz.

_| I to find the square of | + V'— -^

I + ;^Z! I forthe product (i+ V— i) X (i~/— I)

£5© DEPECTIYE ALGORITHW OF IMAGINARY QUANTITIE«|.

1 31 ^Hf I to find the square of 4. — y'— f

Therefore

^^^ //'-U— V-f) + 2 + //-(^+V-|) or

''=2 — p/i - V-i - ^i + V-f or

and therefore by addition, we have

Now if this be a legitimate result, I see no reason why this
value of a* should not be considered asa root of the proposed
equation as well as the other two; and if it be admitted as
such, then I can tind any number of other roots at pleasure ;
which will totally destroy the established theory of equa-
tions; but if, on the contrary, this cannot be admitted as a
root, then it necessarily follows, that the present algorithm
of imaginary quantities is defective, or otherwise that I have
deviated from that algorithm in the preceding operation.
In order to discover the errour wherever it moy lie, and that
the connection of it may be made public, 1 am induced to
request the publication of this paper in your Journal ; which,
if you should think proper to comply with, will much oblige

Yours &c. %

MATHEMATICUSe

HI.

OS THE NATURE OF HEAT. 257

III.

On the Nature of Heat. By Marsh Alt Hall^ Esq. In
a Letter from the Author,

{Concluded from p. 222.y

N appreciating the merit of any hypothesis, we ought cer- Some assump-
tainly to consider, what assumptions are inseparable ^''^m jj^^p^^^j^ ®
the subject itself; and what suppositions are necessary, to from a subject,
constitute the particular hypothesis proposed. '^^^tS^^'^h

To apply this to our subject; it appears to me, that, particular yievr
whatever may be our notion concerning the ultimate nature *'^^'*
of caloric, one postulate must necessarily be made; the ex-
istence of a channel for this agent between the Sun and the
Earth must unavoidably be assumed.

If we embrace the opinion of the materiality of caloric. Suppositions
we suppose, that this matter emanates constantly from the w^f'hth? mate-
sun's surface; and penetrates space. On the other hand, riality, and
in adopting the opposite opinion, we necessarily suppose the ^"^^^*^"**^^y
existence of a fluid, naturally pervading the universe in a
state of quiescence; but ready to be impressed by external
causes. This is indeed the great difficulty ; and a difficulty,
which no one will pretend to obviate. It may diminish the
objection, which is thus afforded to the hypothesis, to ob-
serve, that on either side of the question the difficulty is
nearly the same ; or, if there be any difference, it is in fa-
vour of the hypothesis of vibration. For what is the great
difference, between the assumption of a material agent,
which, being impelled, penetrates space with rapid motion ;
and that of a quiescent fluid pervading space, and subject
to certain impressions ?

But, if we consider this circutnstance farther, we shall Most assump-

observe, that, in the material theory, the Assumption of one *^°"^ !".^^^
/, . J , J -. A , . material hypo-

tiuid only does not sufSce. According to this opinion, the thesis.

sun-beam must consist of at least three; or, if we consider
the compound nature of light, of no less than of nine dis-
tinct fluids. Many persons however will be willing to grant
all these to modern theorists, who would refuse to Huygens
Vol. XX1X,-*AUGCST, 1811. S and

258 ON l^li NATi.«^RE OF HEAT.

and Euler their ethereal medium ; althouj^h both supposi-
tions are equally hypothetical.
Neglect of in- It fnust be acknowledged, that in investigating the nature
ductien of caloric, we subject ourselves to the imputation of false

philosophy. We neglect the method of induction, and seek,
as the ancients did, occult causes. So much are we involved
in the trammels of theory, that we are scarcely able, in some
and recourse u> ^'^'^^^^^^s* ^^ express a single fact, without implying the ex-
hypoihcsis too istence of something perfectly hypothetical ; this is very
much the case with our present subject, heat, and with the
science of electricity. AVe are educated in the belief of such
hypotheses, and do not doubt of their truth, until a consider-
able progress has been made in the study of them. It ig
not one of the least of the uses of investigations like the
present, to teach us how very little all hypotheses ought to
be relied on, and how very much and how constantly they
ought to be distrusted.

The Nature of the Vibration of Heat,

Kature of the Heat may possibly depend, not on the presence of any
Vibration of material fluid in the interstices of bodies, but on a state of
intimate vibration of their particles. The temperature or
' degree of heat may be greater or less, according as these

vibrations may be more or less frequent in any given time;
or, as it may be expressed, according to the intensity of the
vibration. By this term I wish only to express the relative
state of the vibration; that vibration I suppose to be the
most intense, which occasions the highest temperature.
Objection to ^" objection which has always been urged to the hypo-
the hypothesis, thesis of vibration is, that the propagation of heat does not
obey the established laws of motion. '* Were they the same,
its propagation ought to be momentary through elastic bo-
dies, and should be more or less rapid through others, ac-
cording to their elasticity."

Answer to the '^^ *^^ ^""^^ P^*"^ ^^ ^^'^ objection, it may be answered,
first part of it. that the propagation of heat through elastic bodies is indeed
momentary ; for this is the radiation of caloric. Previously^
to considering the second part of the objection, it will be]
necessary to consider somewhat of the nature of the vibra-
tions,

OTi THE NATUItE OF HEAt.

Q59

tions, which we have supposed to constitute heat; and to
show in what respect they differ from other vibrations.

The important and manifest difference between these ?i- Difference be-
brations, of sound, for example, and of heat, is, that in ^j^^^j^^j ^f
the former the mass, in the latter, the particles only of that heat and
mass, vibrate; and this distinction is sufficient to explain the *°""
necessary and consequent difference in the laws observed by
these vibrations. The facility with which ihe mass of any
body vibrates will be proportionate to the elasticity of the
body; but it is plain, that the vibration of the particles of
the fuass will obey laws as different as the vibrations them-
selves are different: accordingly, who, after this considera-
tion, vvould expect thai the elasticity of any body should
regulate the vibration of its particles only? It is argued
indeed, that the vibration of the mass of any body must
ultimately be referred to tht condition of its particles; this
I readily admit: yet it proves nothing; it does not prove
that the converse of this is true; namely, that the vibration
of the particles must be determined by the condition of the
ma'os.

Perhaps it was the want of considering^ the necessary dif- Other objec*
ference between the vibrations of heat and of sound, that ^'°"^*
has led to some other objections to this theory. It has been
said, that no body could communicate heat to another, (if
heat were vibration), unless the second made a sort of con-
cord with the first. Another objection is still more futile;
the vibrations, if such constituted heat, would, it is said,
** gradually relax and die away,"

Sources of Caloric,

For the same reason, that this part of the subject wae Sources of
tiealed with brevity in the former part of this discussion, 1 ^^^'•
niiy be equally concise in this place. The intimate connec-
tioi between motion, friction, percussion, &:c. and heat,
has lately been so much attended to, and so satisfactorily
explained by the theory of vibration, that nothing scarcely
rennins to be added on this point.

Ihe light and heat produced by the transition of the elec-
tric fluid from one body to another is extremely" analogous
to tie sound produced by the motion of air through tubes.

S 2 If

260

ON THE KATURE OP ttSAT,

Motton of
heat.

If the transition be sudden, powerful light and heat are oc-
casioned ; if it be slow and equable, a continual spring of
light and heat is formed. In the same manner, if the mo-
tion of air be rapid, a sound is produced as powerful as the
heat and light, in the first instance ; if the motion of the air
be slow and equable, the sound produced is smooth and un-
interrupted.

Motion of Caloric.

It has been said, that the best conductors of caloric re-
ceive and part with this power the most rapidly. This is
precisely what our hypothesis would have led us to expect,
a priori. It is to be remarked, that the action of hot and
cold bodies upon each other is reciprocal. The heating and
cooling of bodies is, according to our opinion, the same
operation; both are reducible to the effecting a change in
the state of vibration ; and different substances are suscep-
tible of this change in different degrees ; those which are
most so are the most easily heated, and the most readily
cooled.

This explanation applies equally well to the absorption and
radiation of heat and cold ; which are perhaps greater diffi-
culties in the opposite opinion, than even the circumstance
with respect to conducting power.

It was formerly stated, that radiant heat Is extremely dif-
ferent, according as it comes from the sun, or from a source
of heat upon Earth ; I wish however to state this difference
somewhat more distinctly.
From the sun. That the heat of the sun is transmissible through and re-
frangible by transparent media, is abundantly proved ; t^e
: refrangibility of the heat accompanying the coloured ptrt
of the prismatic spectrum, and of the invisible rays of so-
lar heat, is shown in the 13th and jyth experimentJ of
Dr. Herschel*; and the familiar use of burning lenses de-
monstrates the refraction of the caloric of the undecomposed
solar ray.

On the other hand, that culinary heat is not transmi«ible
through any solid body is very decisively proved by thi va-
luable experiments contained in Mr. Leslie's third chapter:
see the inquiry. '

• PhU. Trans, fer 1800: or Journal, 4to Series, Vxrf. IV, p. ^^4, 36fi.

/ The

Radiant heat.

From a fire.

ON THE NATURE OF HEAT. QQI

The latter statement requires however some qualification The latter in

and restriction; for 1 must now observe, that, allhoneh '''^"•^ ^.^^'^'f
_.,-., . 1 -J II 1 i/v • uuasmissible,

iVlr. l-eslie s experiments prove decicledly the ditterence be-

tvi'eeu solar and culinary heat in this respect, yet he has I
believe proceeded too fur, in asserting, that the latter is not
at ail transmissible through transparent media. That the
heat of a candle is in some degree refracted by glass is prc7«l
by the 13th experiment of Dr. J^erschel ; the heat of a com-
mon fire was transmitted and refracted in the 14th and l6th ;
the heat of redhot iron was refracted in the 15th; and invisi-
ble culinary heat was refracted in the 19th and 20th experi*
ments*. The heat emanating from a candle, from a boiling;
mixture of sulphuric acid and water, and from boiling wa-
ter, was transmitted through glass, in some experiments per-
formed by my friend Mr. Maycock f.

The whole of these experiments concur in establishing a butnotequally
remarkable difference, between the transmission of radiant ^^ ^°^^^ ^^^^*
culinary and solar heat. Solar heat is scarcely if at all im-
peded, culinary heat almost entirely intercepted by transpa-
rent media I

But this is not the only difference between solar and culi- Difference m
nary heat ; another distinction is observed in their reflection, 'h« reflection
«* Cover each ball of a differential thermometer with a coat culinarv^heau
** of tinfoil, and rub that one below which the scale is af-
** fixed gently with sand paper; or it may be rubbed before
" it is applied to the glass. Placing the instrument now in
*« the sun, the liquor will visibly rise, perhaps 5 or 10 de-
grees." *' Set this differential thermometer now directly
opposite the fire, and about two or three feet distant from
** it. In this situation a very remarkable depression will
** quickly take place, equal perhaps to 30 or 40 degrees.'*
** This beautiful experiment likewise indicates clearly the
** distinction between the solar rays and culinary fieat J.'*

The explanation of this phenomenon, which follows its Attempt to ac-
relation, will not, I conceive be readily acquiesced in; '* the count for this*
* light from the fire, has," it is said, " some tendency, to

<(

i

» Phil. Trans. 1800 j or Journal as above,
•; Phil. Journal, Vol. XXVl, p. 75.
Iloquirj, p. 8S> et t«^.

•* counteract

262

ON THE NATURE OF HEAT.

Other differ.
ences.

Why solar
heat passes
through trans'-
parent bodies
•wholly J

other h«at only
in part.

Other differ-
ences.

Opaque bo-
dies.

" counteract or diminish in a certain measure the peculiar
" effect of the heat emitteJ from the same source."

Another ditierence still between ihe two kinds of heat was
discovered by Mr. Leslie. A very considerable aberration
takes place in the reflection of culinary heat, which is not I
believe the case with the solar rays, Kor is the etlect of
colour, in absorbing- the two kinds of heat, the same. —
♦* Stained paper has very nearly the same action as white
*' paper, and it is only when cjjvered by a pigment super-
" induced, that th'e diversity ol' tffect becomes conspicu-
"ousV*

I shall now attempt to explain this remarkable difference
between solar and culinary heat. Solar heat may consist of
vibrations in that medium or fluid, which we^ suppose to fill
space. This fluid is one of extreme tenuity, and pervades
all bodies without exception ; vibration therefore, which
subsists in this fluid, does and ought to pass through such
bodies as are transparent, "witii little or no interruption.
Radiation from other bodies, that is radiant culinary heat,
is very different : the radiator is in a state of vibr;ition ; this
vibration is communicattd to all surrounding bodies, the
most iiQfiortant of which is the atmosphere ; the subtile fluid
too must be taken into consideration ; these, with other bor
dies, which are within the vicinity of the source of heat, take
on vibration, and convey it to distant surfaces. In as much
as the vibration subsists in the more subtile medium, it will,
as it did in the case of solar heat, pervade transparent bodies ;
but the chief conductor of heat in this operation is the
*' ambient air;'* this fluid does not pervade transparent or
other bodies, its vibrations will therefore be intercepted by I
thecj.

It is easy to conceive, that, as the two kinds of radiant
heat are so extremely different, the laws which are observed
in their other motions shall be very different; a difference in
their reflection and absorption is what might have been ria-
u rally expected.

From some cause, the pervading fluid of certain bodie>
does not propagate its vibrations; these bodies are therefoie

Inquiry, p.. ^4.

opacwe

ON THB NATURi. OF HEAT. QSSt

opaque*. It is from this circumstance, that opaque bodies
only are heated by the sun's rays; in intercepting th*tp»
they receive the heating power, the vibration of these rays*
Such bodies act upon solar heat somewhat in the same
manner ns all bodies act upon culinary heat.

From this view of the subject it appears, that air is a very Air a quick
quick conductor of heat; Berthollet has remarked this j^^^^^
factf* nevertheless air is employed in the arts as a bad
conductor : this circumstance requires some explanation.

Different bodies are susceptible^ in difterent, degrees, of Conductinj^
undergoing a change in their vibration ; and, having suffered P°^^''='^ ^^ ^^'
a change in their vibration, they convey this change to dis-
tant parts with different degrees of celerity, Caeteris pari-
bus, those bodies, which are most susceptible of change in
vibration, induce the least change in other bodies; and, coe-
teris paribus, those bodies, whiciiconvey the changes thej may
have suffered with most celerity, produce the greatest change
in other bodies. Thus the conductor, which occasions the
greatest change in temperature, is that vvhicb.unites the proper-
ties of celerity of conducting power and little susceptibility of
change in vibration : and thus, although air conducts vibra-
tion with much celerity, yet, from its high susceptibility of
change in vibration, its effect in augmenting or reducing the
temperature of bodies is by no means great. It appears
that the terms good and bad conductors are involved in some
ambiguity.

Radiation of Cold. Radiation of

This phenomenon appears to me to be the most decisive cold.
in demonstrating the true nature of caloric; it deserves per-
haps the appellation of experimentura crucis. Effect of a con.

A concave mirror has the property of concentrating the cave mirror.
rays of vibration proceeding from a source properly opposed
to it. In a similaf manner the vibrations of air constituting
sound are converged in an eliptical chamber. The opera-
tion of mirrors does not however increase the intensity of the

* It is necessary to remark, that I have considered the theory of light
of Huygens and Euler as the most probable j a few observations on this
subject may probably at some future time be tiansmitted to the Philoso-
phical Journal.

t Murray, Vol, J, p. 374.

vibration

964 ^^ '^^^ NATURE OF HEAT.

vibration of rays, it merely causes them to converge, collects
and unites their effect. The intensity of vibration in th«
focus of the mirror is not greater than that of each of the
rays before they converged ; but as the force of all the rays
is concentrated in the focus, the heating etiect will be greater
there; that is, a body in the focus will be heated much
sooner than by the operation of a single ray, but will never
attain to an intensity of vibration arreater than that of a single
ray. In like manner, althoui^h the force of rays of sound be
accumulated in the focus of an elliptical chamber, yet the
note, or pitch of the sound, i. e. its intensity of vibration,
remains the same.

Now vibrations of a certain intensity occasion the sensa*^
tion and phenomena of cold ; the accumulation of rays of
vibration of this intensity by means of a concave mirror, as
before, does not alter their intensity, but merely converges
and collects their force, and thus increases the effect of pro-
ducing co'd ; and this it does, to the very same extent, pro-
vided all circumstances be equal, as the effect of producing
Experiment, beat was increased by converging the rays of heat. I have
endeavoured to ascertain this by experiment. The tempera-
ture of the atmosphere was 60*. Two mirrors were properly
opposed to each other ; in the focus of one was placed a ther-
mometer, in that of the other a cubical canister, one side of
which, (namely, that opposed to the mirror), was blackened.
The canister was now filled with water at 90°. The effect
on the thermometer in time and extent was marked: the
canister was then removed, and its place supplied by a similar
one containing A saline solution at 30*. The eff*ect on the
thermometer was opposite, but equal in time and in degree,
to that of the former experiment.

This fact is of an importance not to be easily appreciated;
it appears to me to identify heat with vibration.

Effects of Heat.

H^tQUofheat, In the former part of my paper I have related some facts,
which are not only inexplicable on the theory of repulsive
caloric, but which appear to afford some degree of contra-
diction to it J it will therefore appear, that an explanation

of

ON THE NATURE OF HEAT. ^55

of these facts must necessarily proceed on some other prin*

It is certain, that two ener^jetic, but opposite powers,. are Attraction ^ni
constantly active, in all the operations of chemistry; these '^^^^^^"''^
are attraction and repulsion. The nature however of these
powers is still very uncertain : the effects of heat are all re-
ferrible to changes in their condition ; but from our igno-
rance of their nature, it must be extremely difficult, to
ascertain with precision the cause and nature of the changes
they undergo.

The phenomena which I have mentioned as contradictory Accounted for
to the theory of repulsive caloric have been ascribed to the 7 ^^^"^
agency of a certain polarity in the particles of the body ; by
means of this polarity the particles are opposed to each other
in a particular manner; and the state of attraction and re-
pulsion is influenced or regulated by this state of apposition.
The change in temperature is the cause of the change in the
apposition ot' the particles; and this change of apposition of
the particles proves the cause of the change in the state of
attraction and repulsion, and consequently of the bulk of
the body.

This explanation is probably correct; and if it apply in Change of
one instance of changes produced by temperature, why not J^"^*^ ^'^<'™
in all? The greatest density of water seems to be about
the temperature of 38**. If its temperature suffer any
change from this point, expansion occurs; and for any
given number of degrees above or below this temperature,
the expansion is the same, if the water retain the fluid
force. Here therefore, the effects are precisely similar, but,
according to the theory, they are ascribed to causes that are
different; which in itself appears to me contraiy to the true
laws of philosophising. This opinion, therefore, and the
objections which I have mentioned to the usual explanation,
have induced me to refer the changes of bulk from tempera-
ture, in every case, to the same cause; whatever the cause
may be.

There are many circumstances, which tend to corroborate Circumstancet
the idea of polarity. The appearances of crystallization ap- h"ypoth"I[f^*
pear to depend on its agency. The state of fluidity of bodies polarity,
must also be referred to the ** particular situation" of their

particles^

266

Expansion of
water.

Capacity for
heat.

Mercury and
water.

Cibabgein ca-
pacity.

oi^ TiiE NitrfitE or keat.

pnHicles. And I can conceive-, that the agency of attraction,
whether oi' aggregation or of composition, may in every case
be iiifluenced or regulated by the pavticiilar state of'apposi-
tion of particles. .

It will readily be acknowledged', that m'udi difficulty and
uncertainty still exist in this qnestioii ; but I conceive, that
the difficulties areinconliparably greater in relation to the the-
ory of repulsive caloric, than in the view ofthe subject, which
has been given. If we could explain the cause of the ex-
pansion of water, cooled from 40° to 10°, we should probably
find little difficulty in understanding the similar arid pre-
cisely equal expansion, when the same water is raised in its
temperature from 40° to 70°.

Capacity for Caloric.

It ^^ould be extraordinary indeed, if all bodies were
equally susceptible of vibration ; no property of matter is
equally possessed by all the innumerable substances, which
nature presents to our attention ;' gravity, hardness, elas»
ticity, &c. are possessed in ari equal degree by no two bodies
with which we are acquainted: such is the diversity in
Nature's works ! Nor are all bodies equally susceptible of
change in the state of their vibration. This proposition is
sufficient to account ibr the variety in the capacity of dif-
ferent'bodies, and ofthe same body under different forms,
for heat. Mercury is more susceptible of vibration than
water; solids than fluids; fluids than gasses :ihe quanti-
ties, for CO ui pari son, being ascertained by weight*.

Let mercury at 40° be mixed with an equal weight of
water at 80°; mercury is more susceptible of change in the
state of its vibration than water, and will consequently suf-»
fer more change ; its intensity of vibration will pass more
nearly to that of the water, than the intensity of vibration in
the latter will to that of the mercury : the resulting tempe-
raturie will therefore be above the mean ; i. e. more nearly
that ofthe water than the mean. If the experiment be re-»
versed, the effect will also be reversed.

K* during the time of the change in the susceptibility of
any body for vibration (this change being to diminish its

* In speaking formerly ofthe high susceptibility of air for change in
*jbraiion its quantity was considered by bulk, not by weight.

susceptibility

ON THE NATURE OF HEAT. 25/

susceptibility) heat be communicoted, its temperature may
remain unaltered ; a greater power, or longer application of ~
vibration, being now necessary to occasion a temperature,
which, before the susceptibility for vibration was diminished,
was produced by a power much smaller, or an application
much shorter. Hence steam is no hiii;ber in temperature steam,
than boilino^ .water. If, during this change of susceptibi-
lity for vibration, no farther application of heat be made,
it follows, that the temperature must fall : hence arise the Freezing mix*^
effects of freezing mixtures. lures.

It scarcely need be added, that the converse of all this Corverieof
will take phice, if the susceptibility for vibration be increased,
and no abstract on of heat be made. The temperature then
must rise; for the body contains within itself what may be
termed the power of vibration ; a given quantity of which
produces a greater inteni^ity of vibration in any body, ac-
cording to the susceptibility of that body for vibration.

Such is an iii\perfect sketch of the hypothesis of vibration,
which 1 proposed to give. Many circumstances, which
would have elucidated, and perhaps have confirmed the opi-
nions, have been necessarily omitted ; and here the greatest
candour of your readers will be constantly required.

It may be useful in concluding, to present a summary of Summary,
the circumstances which have been considered; and thus to
institute a comparison between the two hypotheses.

1st, The tirft principles of each opinion are equally hy- The tt/o hypo*
pothetical. the.es com-

j r . ... . pared.

2dly, The production of heat by friction is explained by

the hypothesis we propose; but not, satisfactorily at least,
by the other.

3dly, Certain facts have been related, under the head of
the eft'ects of heat, which appear to afford fome degree of
contmdiction to the hypothesis of material caloric; and
although they may not be easily explained on the opposite
principle, yet they do not by any means appear contradic-
tory to it.

The advantages of our theory appear most conspicuous
in the following particulars; for

4thly, The properties of good conductors, and of good
radiators of caloric, are explaiiicd by it alone.

5thly,

j{g$ COMBINATION OF OXIMURIATIC GiS AND OXIGEX.

5thly, The same observation applies to the difference of
solar and culinary heat;

6thly, And in particular to the radiation oFeold.
7thly, The opinion oF capacity for caloric i& hypothetical ;
thai of the difference in susceptibility for vibration is in
conformity to the usual order of nature, in dispensing the
other properties of matter.

I remain, Sir,

Your very obedient,
Edinburgh, June 8th, MARSHALL KALL.

18IU

IV.

On a Combination of Oximuriatic Gas and Oxigen Gas. Bt/
Humphry Davy, Esq, LL. D. Sec, R, S, Prof, Chem»

If SHALL beg permission to lay before the Society the ac-
«Bctgenand ox- count of some experiments on a compound of oximuriatic
imuriatic gas.« g^g ^nd oxigen gas, which, 1 trust, will be found to illus-
trate an interesting branch of chemical inquiry, and which
offer some extraordinary and novel results.
^ . . . I was led to make these experiments in consequence of

gas differs the difference between the properties of oximuriatic gas pre-

wt^endjffer- pared in different modes; it would occupy a great length of
TOtly prepared. ' „,:''. ^ .. ^

time, to state the whole progress or this investigation. It

will, I conceive, be more interesting, that I should immedi-
ately refer to the facts; most of which have been witnessed
by Members of this Body, belonging to the Committee of
Chemistry of the Royal Institution.
Its properties The oximuriatic gas prepared from manganese, either by
when pro- mixing it with a muriate and acting upon it by sulphuric

cored by acid, or by mixing it with muriatic acid, is, when the oxide

Tnt»aD3 of man- » ^ o

gancse. of manganese is pure, and whether collected over water or

inercJiry, uniform in its properties; its colour is a pale yel-
lowish green ; water takes up about twice its volume, and
scarcely gains any colour; the metals burn in it readily; it

♦ ^hU» Trans, for 1811, p. 155.

Combines

COMBINATION OF OXIMURIATIC GJLS AND OXIfiEN. ^(J^

combines witli hidrogen without any deposition of moisture:
it does not act on nitrous gas, or muriatic acid, or carbonic
oxide, or sulphureous gasses, when they have been carefully
dried. It is the substance which I employed in all the ex-
periments on the combinations of oximuriatic gas described
ih ray last two papers.

The gas produced by the action of muriatic acid on the Varies vrhea
salts which have been called hyperoximuriates, on the con- jj °^^j^j^^^
trary, differs very much in its properties, according as the nates,
manner in which it is prepared and coUe61ed is different.

When much acid is employed to a small quantity of salt,
and the gas is collected over water, the water becomes tinged
of a lemon colour; but the gas collected is the same as that
procured from manganese.

When the gas is collected over mercury, and is procured
from a weak acid, and from a great excess of salt, by a low
heat, its colour is a dense tint of brilliant yellow green, and
it possesses properties entirely different from the gas col-
lected over water.

It sometimes explodes during the time of its transfer
from one vessel to another, producing heat and light, with
an expansion of volume; and it may be always made to ex-
plode by a very gentle heat, often by that of the hand*.

It is a compound of oximuriatic gas and oxigen, mixed A compound,
with some oximuriatic gas. This is proved by the results
of its spontaneous explosion. It gives off, in this process,
from ^ to f its volume of oxigen, loses its vivid colour, and
becomes common oximuriatic gas.

I attempted to obtain the explosive gas in a pure form, Attempts t©
by applying heat to a solution of it in water; but in this ^ '^ *' ^^**
case, there was a partial decomposition; and some oxigen

* My brother, Mr, J. Davy, from whom I receive constant and able
assistance in all my chemical inquiries, had several times observed explo-
sions, in transferring the gas from hyperoximuriate of potash, over mer-
cury, and he was inclined to attribute the phaenomenon to the combustioix
of a thin ftlm of mercury, in contact with a globule of gas. I several
times endeavoured to produce the effect, but without success, till an acid
vras employed for the preparation of the gas, so diluted as not to afford it
without the assistance of heat. The change of colour and expansion of
volume, when the effect took place, immediately convinced me, that it
was owing to a decomposition of the gas.

was

^'J'O COMBINATION OF OXIMURIATIC GAS AND OXIG£N«

was disengaged, and sonae oximuriatic gas formed. Find-
ing that, in the cases when it was most pure, it scarcely
acted upon mercury, I attempted to separate the oximuri-
riatic gaswitlj which it is mixed, by agitation in a tube with
this metal ; corosive sublimate formed, and an elabtic fluid
was obtained, which was almost entirely absorbed by ^ of
its volume of water.
Dangerous. This gas in its pure form is so easily decomposable, that

it is dangerous to operate upon considerable quantities.

In one. set of experiments upon it, ajar of strong glass,
containing 40 cubical inches, exploded in my hands with a
ioud report, producing light; the vessel was broken, and
fragments of it were thrown to a considerable distance.
Analysis of it. I analysed a portion of this gas, by causing it to explode
over mercury in a curved glass tube, by the heat of a spirit
lamp.

The oximuriatic gas formed, was absorbed by water ; the
oxigen was found to be pure, by the test of nitrous gas.

50 parts of the detonating gas, by decomposition, expanded
so as to become 60 parts. The oxigen, remaining after the
absorption of the oximuriatic gas, was about 20 parts. Se-
• veral other e.^periments were made, with similar results. So
that it may be inferred, that it consists of 2 in volume of
oximuriatic gas, and 1 in volume of oxigen ; and the oxi-
g6n in the gas is condensed to half its volume. Circum-
stances conformable to the laws of combination of gaseous
fluids, so ably illustrated by Mr. Gay-Lussac, and to the
theory of definite proportions.

I have stated on a former occasion, that approximations
to the numbers representing the proportions in which oxi-
gen and oximuriatic gas combine are found in 7*5 and 32*9«
And this compound gas contains nearly these quantities*.

The

* In pipe 245 of the Phil. Trans, for 1810, (Journal, vol. XXVII, p.
ii33j) 1 have mentioned, that the specific giavity of oximuriatic gas is
between 74 and 75 grains per 100 cubical inches. The gns, that 1
weighe;!, was collected over water, and procured from hyperoxirauriate of
potash, and at. that lime 1 conceived, that this elasiic fluid did not difFff
f ora the oximuriatic gas from mangenese, except in being purer. .It
lfp<c ^rar. of probably contained some of the new ga^j fur 1 find, that the specific gra-
vity

COMBINATION OF OXIMURIATIC GAS AND OXIGEN. £71

The smell of the pure explosive gas somewhat resembles Smell of the
that of burnt sugar, mixed with the peculiar smell of oxi-
muriatic gas. Water appeared to take up eight or ten Solubility,
times' its volume; but the experiment was made over mer-
cury, which might occasion an errour, though it did not
seem to act on the fluid. The water became of a lint ap-
*proachingto orange.

When the explosive gas was detonated with hidrogen Attractioa of

equal to twice its volume, there was a great absorption, to oximunatic

, t I . t> .... „ - gas for hid(0-

more than f, and solution of muriatic acid was formed ; gen.

when the explosive gas was in excess, oxigen was always ex-
pelled, a fact demonstrating the stronger attraction of hi-
drogen foroximuriatic gas than for oxigen.

I have said that mercury has no action upon this gas in Action of the
its purest form at common temperatures. Copper and an- ^"jajg" "
timony, which so readily burn in oximuriatic gas, did not
act upon the explosive gas in the cold : and when they
were introduced into it, being heated, it was instantly de-
composed, and its oxigen set free; and the metals burnt in
the oximuriatic gas.

When sulphur was introduced into it, there was at first sulphur,
no action, but an explosion soon took place : and the pecu-
liar smell ofoximuriateof sulphur was perceived.

Phosphorus produced a brilliant explosion, by contact phosphorus,
with it in the cold, and there were produced phosphoric acid
and solid oximuriate of phosphorus.

Arsenic introduced into it did not inflame ; the gas was arsenic,
made to explode, when the metal burnt with great brilli-
Hucy in the oximuriatic gus.

Iron wire introduced into it did not burn, till it was iron,
heated so as to produce an explosion, when it burnt with a
most brilliant light in the decomposed gas.

Charcoal introduced into it ignited, produced a brilliant charcoal,
flash of light, and burnt with a, dull red light, doubtless

vity of pure oximuriatic gas from manganese and muriatic acid is to that oximuriatic
of common air, as 244 to 100. Taking this estimation* the specific gra- gas,
yiry of the new gas will be about 238, and the number representing the
proportion in which oximuriatic gas combines, from this estimation, will
ha rather higher than is stated above,

owing

37i

mrroKS gas^

iBuriatic add
fas.

Wby ihe com-
pound was nol
before ob*
»eiTed,

Hfperoximth-
riatk ackl of
S*Ir. Chevenix.

Explosion*
from hyper-
oKimuriates.

All the facts
Confirm the
simple nature
«f oximuriatic

«••-.

COMBrNATION OF OXtMtJRtATIC GAS AND OXIGEK.

owing to its actiou upon the oxigen mixed with the oximu-
riatic gas.

It produced dense red fumes when mixed with nitrous
gas, ftnd there was an absorption of volume.

When it was mixed with muriatic acid gas, there was a
gradual diminution of volume. By the application of heat
the absorption was rapid, oximuriatic gas was formed, and a
dew appeared on the sides of the vessel.

These experiments enable us to explain the contradictory
accounts that have been given by different authors of the
properties of oximuriatic gas.

That the explosive compound has not been collected
before is owing to the circumstance of water having been
used for receiving the products from hyperoximnriate of
potash, and unless^ the water is highly saturated with the ex-
plosive gas, nothing but oximuriatic gas is obtained ; or to
the circumstance of too dense an acid having been em-
ployed.

This substance produces the phenomena, which Mr. Che-
nevix, in his able paper on oximuriatic acid, referred to the
hyperoxigenised muriatic acid ; and they prove the truth of
his ideas respecting the possible existence of a compound of
oximuriatic gas andoxigem in a separate state.

The explosions produced in attempts to procure the pro-
ducts of hyperoximnriate of potash by acids are evidently
owing to the decomposition of this new and extraordinary
substance. ' ^^

All the cohcUisions, which I have ventured to make re-
specting the undecompouuded nature of oximuriatic gas,
are, I conceive, entirely confirmed by these new facts.
'^ If oxiriihTintic g^fe contained dxl gen,' It fs not easy to^ con-
ceive, why oxigen should be afforded by this new compound
tb muriatic gas, which must alrxVady contain oxigen in inti-
ftliate union. Though on the idea of muriatic acid being a
compound of Ijidrogen and oximuriatic gas, the phenomena
are such as might be expected. 4r^ i^s^s

If the power of bodies to burn in oximuriatic gas depended
upon the presence of oxigen, they all ought to burn with
much more energy in the new compound ; but copper, and
iantimony, and mercury, and arsenic, and iron, and sulphur

have

COMftlWATIOir OF OXIMURIATIC OAS AND OXIOE^. QJS

have no action upon it, till it is decomposed ; and they act
then according to their relative attractions on the oxigen, or
on the oximurlatic ^as.

There lo a simple experiment, which illustrates this idea; Experiment
Let a glass vessel containing brass foil be exhausted, and the
new txas admitted, no action will take place ; throw in a little 'i

nitrons ^as, a^rapid decompo'siliou occurs, and the metal
burns with great brilliancy.

Supposing oxioen and oxi muriatic gas to belong to the
game class of bodies; the attraction between them might be
conceived very weak, as it is found to be, and they are easily
separated from each othtr, and made repulsive, by a very
low degree of heat.

The most vivid effects of combustion known are those pro- Esfplosion,
duced by the condensation of oxiifen or oximuriatic gas; but y^^^^ '^^^^ ^^^
in this instance, a violent explosion wuh heat and'bght are j > any ing ex-
produced by their separation, and expansion, a perfectly tension,
novel circumstance ill chemical philosophy.

This compouxid destroys dry vegetable colours, but first The com.

gives them a tint of red. This- and its considerable ab- P®""*? ^^Z
preaches to an

sorbability by water would incline one to adopt Mr. Chene- acid.

vix's idea, that it approaches to an acid in its nature. It is

probably combined with the peroxide of potassium in the

hyperoximuriate.

That oximuriatic gas and oxigen combine and separate Oximuriatic

from each other with such peculiar phenomena, appears ^^^ apparentlf
, . , . » rr simple, and of

strongly in favour of the idea of their being distinct, though the same na-

analogous spjecies of matter. It is certainly possible to de- ^^^^ ^'^^ ^^'

fend the hypothesis, that oximuriatic gas consists of oxigen

united to an unknown basis; but it would be possible like-

wise to defend the speculation, that it contains hidrogen.

Like oxigen it has not yet been decomposed ; and 1 some-
time ago made an experiment, which, like most of the others
1 have brought forward, is very adverse to the idea of its
containing oxigen.

I passed the solid oximuriate of phosphorus in vapour, Exp«riraenl,
»nd oxigen gas together through a green glass tube heated
to redness.

A decomposition took place, and phosphoric acid was ^

formed, and oximuriatic gas was expelled.

Vol. XXIX.— .AwousT, 1811. T Now,

274

NEW THR1SHIN« MACHINE.

Now, if oxigen existed in the oxirauriate of phosphorus,
there is no reason why this change should take place. Ow

, ^ the idea of oximuriatic gas being undeeompounded, it is

easily explained. Oxigen is known to have a stronger at-
traction for phosphorus than oximuriatic gns has, and conse-
quently ought to expel it from this combination.

Nomenclature. As the new compound in its purest form is possessed of a
bright yellow green colour, it may be expedient to designate
it by a name expressive of this circumstance, and its relation
to oximuriatic gas. As I have named that elastic fluid
. chlorine, so 1 venture to propose for this substance the name
euchlorine, or euchloric gas from iv and y\ufos. The point
of nomenclature I am not, however, inclined to dwell upon.
I shall be content to adopt any name, thai may be consi-
dered as most appropriate by the able chemical philosophers
attached to this Society,

Inducements
to the inTea>
tion.

Its success.

V.

Description of a new Thrashing Machine, invented by H. P»
L,EE, Esq, of Maidenhead Thicket*,
SIR,

JL BEG leave to state to the Society of Arts &c. t^e follow-
ing particulars, relative to my attempts to improve the
thrashing raachinp: for corn, and of my success therein.

Being largely concerned in agriculture, and having 800
acres of arable land, I found, that a thrashing machine or
two became absolutely necessary for the continuance of my
occppations. I accordingly erected.oneof the kind recom-
mended to me ; but from the complication of its structure,
ita being frequently out of order, and from its bad perform-
ance of the work at all times, I resolved to try to have a
thrashing machine made under my own directions, more
simple in its construction, and more efficacious in its opera-
tions. With this view I have continued ny experiments

• Trans, of the See. of Art», Vol. XXVIII, p. 25. The premium of
the gold medal, oiFercd by the Society, was adjudged to Mr. Lee, for this

machine.

for

in£^ THRASHING MACHINE. ^5

for nearly tliree years, at an expense of about three hundred
pounds, and have, at last, brou<^ht my machine to a degree
of perfection, which is satisfactory. Many gentlemen and
farmers, Who have seen it and its operations, give it a decided
preference to any they have seen, for the simplicity of its
construction, for the cleanness of its thrashing, and for the
quantity of corn thrashed by it, in proportion to the power
applied.

I have no doubt but that the result of my original thoughts
and experiments on this subject will be of great advantage in
this highly useful agricultural implement, and I have sent
a model of th^ mqrhine for the Society's inspection.

I am, Sir,
Your very obedient Servant,
Maidenhead Thicket, H. P. LEE*

i:><?c.27, 1809.

Certificates from Mr. Edward Green, of Bowlney, in Ox- Testimonies of
fordshire, and Mr.' Thomas Michlem, of Hurley, in Berk* its excellence,
shire, stated, that they are largely concerned in the agricul*
tural line ; that they have seen a variety of thrashing ma*
chines, but give the preference to those on Mr. Lee's prin*
ciple, for the simplicity vof their construction ; that they
highly approve of ihe manner, in which they perform their
work; and that they consider them as calculated to thrash
more corn, in proportion to the power applied, than any-
other they have seen.

Certificates from William Hubbeard, of Maidenhead
Thicket; Thomas Williams, of Feeres Farm, in White
Waltham ; Joseph Lee, of White Waltham ; and Richard
•Silver, of Maidenham Thicket; testified, that, on the 27th
of February, 1810, Mr. Lee's thrashing machine did thrash Effect pro-
in one hour and fifty-five minutes, eight quarters and three ^""** ^^ ^' ®"
bushels and a half of barley; that the straw was thrashed
clean, and not broken; and the work was in all respects
performed in a workmanlike manner. *

A certificate from Jamed Willis, foreman to Mr. Lee, and on oat»,
stated, that, on the S^th and 48th cf jTebrtiary, 1810, he
, T« did

276 NEW THRASHING MACHINE.

did thi*ash thirty quarters of oats with Mr. Lee*s machine,
at Highway Farm, in the parish of Cookham, Berkshire.

SIR,

After inspecting several Thrashing Machines by a variety

of milkers, I saw and examined yours, at Highway Farm,

and was impressed with its superiority over every other that

I had seen, both on account of its si mphcity and effect. I

Thrashes apphed to Wric:ht, your builder, who has erected one for

wheat and bar- ^^ •,••,,.. ^ i, ^i u

ley clean with- ™^ upon your improved prmciple, which ctiectually thrashes

out injury to wheat and barley clean, without iniurina: the straw, and very
the straw. , /„ . , , i • , . i i

much toi my satisfaction. I have not hitherto had an oppor-
tunity of ascertaining its powers with other grain, but ani
happy to assure you, that I consider j'our improvements to
. constitute a material step toward perfecting an instrument
of the first consequence to the agricultural interests of this
kingdom, and highly deserving our warmest acknowledg-
ments.

I have the honour to subscribe myself. Sir,

Your obliged humble Servant,
SAMUEL NICHOLLS, M. D,
Hinton Hovse, Twyford, Berks,
March 1, 1810.

Farther testi- A certificate from Mr. G. H. Crutchley, of Sunning Hill

monies. Park, Berks, dated March 3, 1810, stated, that he had

seen Mr. Lee's thrashing machine at work ; that it thrashed

clean, and pleased him so well, that he had ordered one ob

the jsame principle. ' - ;

By subsequent letters received from Dr. Nieholls and

Mr, G. H. Crutchley, the above certificates were confirmed

by them, with additional testimonies in favour of Mr. Lee*s

machines.

Account of the Mr. Lee, in his attendance on the Committee appointed

machine«nd ^y the Society for the examination of the merits of his ma-
lU working. , . i mi i • . •

chme, stated, 1 hat his machine requires no rollers for enterAj-;

iqg the corn to be thrashed.

That 1

If EW THRASHINO MACHINE. *277

That it is about three feet diameter, and about two feet
aix inches in length.

That two horses are quite sufficient to work it ; that from
half past seven to two o'clock they will, without fatigue,
thrasl) two loads of wheat, each of torty bushels.

That he thinks the straw is not so much broken as with
other machines. ' .

That the van*;8 within fhe cylinder turn frona one hundred
to one hundred and twenty times round for one round of the
horses, in a space of twenty-two feet diameter.

That there are four vanes within the ^rum or cylinder,
each vane one inch and a half thick, and enclosed to within
about three iiiches of their exterior edges; that the drum or
cylinder, within which the vanes turn, is close-fluted with
wood of about an inch thick, and is in movable parts, so as
to admit of being placed nearer to, or farther from, the
vanes, as the corn to be thrashed may require.

That he has erected two of these machines on his estate,
and has used them for three years.

A note se. t to the Society by William Wright, of Henley Price,
upon Thames, Oxfordshire, the maker, states, that the price
of a thrashing raabhine on this principle, including the horse-
wheel, is forty-eight pounds, at his manufactory there.

Reference to the Engraving of Mr, Lee's Thrashing Ma*
chine, PL VII, Fig, 4 and 5.

Fig. 4 and 5 are a side and end-view of the machine; A, Explanation of
in both figures, represents the framing of the machine; B is *^® ?h^^»
the shaft of a cog-wheel C, which is turned by cog-wheels,
from the great horse-wheel, in the same manner as the ordi-
nary thrashing mill ; the cog-wheel C turns a small p-inion D,
to which it gives a rapid revolution ; on the axis of the pinion,
the beaters EE are tixed, and revolve with it, within a seg-
ment or drunr, formed of iron plates, grooved or ribbed, pa-
rallel to the axis, as the tigure represents, and connected to-
gether by wooden curbs FF, to which they are screwed,
a a is the feeding board upon which the corn is placed to en-
ter the machine. The end of this board is fixed very near
to the four vanes, or beaters, b b b b; as these revolve rapidly
they strike the heads of the corn upwards, with such a jerk

as

2.78

BCMP F&OM BBAN STALKS*

as to beat out all the corn from those ears which they ifieet
fairly; but if any escape they are drawn in, together with
the straw, and rubbed round by the beaters against the in-
side of the ribbed drum, or cylinder, F, so as to open the
cars and let out the corn, though the ears come in any posi-
tion whatever. At H is a grating, upon which the beaters
deliv/er the corn, chaff, and strtjw all together; the two former
fall through upon the ground at X, and the latter i^lidesdown
on the grate ; the corn is afterward to be dressed in a win-
powing machine, which s'eparalCH the light and heavy corn
from the chaff. The curbs F are Hxcd by screws, which can
be adjusted so as to bring the cylinder nearer, or farther
from, the beaters, to adapt the machine for thrashing diffe-
rent kinds of grain; for it is evident, that large corn, as
pease, beans, e$cc., must require more space to rub them in
than the smaller grain, as wheat and barley. L, fig. 4, is
one of the uprights of the frame which supports the bearing
for the axis B of the cog-wheel ; and M is an oblique brace,
which strengthens the fame. N is the stage on which the
man who feeds the machine stands.

Fibres in the
stalk of the
l^eaa

exceedingly
strong.

VI.

Account of a Substitute for Hemp, prepared from Bean Stalks,
By the Rev, James Hall, of Chesnut Walk, WaUham-
stow*,

JL HOUGH it has not been attended to, ^or, so far as I
know, ever been mentioned by any one, yest it is certain,
that, according to its size, every bean plant contains from
20 to 35 filaments, or fibres, running up on the outside,
iin(3er a thin membrane, from the root to tlie very top all
around, the one at each of the four corners being rather
thicker, and stronger than the rest. It is also certain, that,
pext to Chinese,, or sea-grass, in other words> the material
with which hooks are sometimes fixed to th<? end of fishing
lines, the filaments, or hempen particles of the bean plant,

* Trans of the Soc. of Arts, vol. XXVUj p. ^7. The silver medal
ivas voted to Mr. Hail.

^ are

HEMP FEOH B^AN STALKS. 979

are among the strongest yet discovered. These, with a little Method of s»-
beating, rubbing, and shaking, are easily separated from the pa^ating tU«r«
strawy part, when the plant has been steeped 10 or 12 days
in water; or is damp, and in a itrtte approaching to fermen-
tation, or what is commonly called' rotting. Washing and
pulling it through hackles, or iron combs, first coarse, and
then finer, is necessary to the dressing of bean-hemp ; and '
so far as I have yet discovered, the easiest way of separating
the filaments from the thin membrane that sunounds them.

From carefully observing the medium numi>er of bean- An aero yieldr
plants in a square yard, in a variety of fields on both sides ^^""* ^ ^^**
the Tweed, as well as in Ireland, and multiplying them by
4840, the number of square yards in an acre, and tbenf
weighing the hemp, or filaments of a certain number of
these stalks, I find, that there are at a medium about 2cwt.
of hemp, or these filaments, in every acre, admirably cal-
culated for being converted into a thousand articles, where
strength and durability is of importance, as well as, with a
little preparation, into paper of all kinds; even that of the
most delicate texture. , ' *' '

Now since there are, at least 200000 acres of ticks, About 2000O

horse, and other beans planted in Great Britain and Ireland ; ^""^ might be

, . , , . ' . f. , , procured an-

and iince, where there is not machmery tor the purpose, the nualJv :n ihe

poor, both young and old, females as well as males, be- ^"'^^ K*"g'
longing to each of the 9700 parishes in England, &c. where '
beans are raised ; might (hemp having risen of late from i)0
to 120 pounds per tun), be advantageously employed in
peeling, or otherwise separating these filaments from the
strawy part of the plant, after the beans have been thresheid
out; I leave it to the feelings of the Society for the En-
couragement of Arts &c. to judge of the importance of the
idea held out here, not only to the poor, but to the land-
holders, and the community at large.

It is nearly twelve months since, by analyzing its com- The hemp
po«ent part?, I discovered hemp in the bean plant. I would ^' "•^^'^ ^ - ^
have written to you then. Sir, on the subject, and sent a ^

specimen, but that I was trying experiments with other
plants, as I am during my leisure hours doing at present ;
and I wished to ascertain in what degree this species of
bemp ia liable to injury from difierent situations, and the

changes

«

280

HEMP FR031 BEAN STALKS.

and to water
with exclusion
of air, v^iihout
iryury.

Before it is
dr««)Sed it is

injured by the
alternate ac-
tion of air and
jaaoisture.

hut is still fit
for paper.

Tlx« water in
■which it is
•teeped per-
haps rather be-
Jieficial than
injurious to

changes of the atmosphere. With a view to this, 1 exposed
one parcel, nearly l-i months, to all the varieties of the air
within doors, and kepi auotner nearly as long constnntly
under water, and find them not in the least injured. The
chief difference I perceive is, that the one kept constantly
under water, namely the whitest of the specimens sent you,
has assumed a rich silky gloss, and a much more agreeable
colour than it had before.

But though this is the case with bean-hemp after it is
cleaned and dressed, and which, though stiff and hard when
dry, is pliable and easily managed when rather damp or wet,
it seems otherwise with it previous to its being separated
fft>in the straw. If bean-straw be kept for years under
water, or quite dry, it produces I find hemp as good and
fresh as at first. But, if the straw be sometimes wet, and
sometimes dry, the filaments or fibres are apt to be injured.
The specimen of bean-hemp accompanying this letter, in
the form of oakum for caulking ships, having been long
exposed to the varieties of the weather, previous to being
separated from the straw, is a proof of its being con^derar
bly injured. If the straw of the bean was scattered thin on
the ground, and exposed to the weather for two or three
months, I have uniformly found that the hemp, or fibres,
afe loosened, and easily separated from the strawy part,
without any other process than rjicrc/^ beating, rubbing, and
shaking them, and perhaps this is the easiest way of ob-
taining bean-hemps but then, from being thus exposed,
and the fermentation that takes place in the strawy part,
which is of a spungy nature, comuiunicaiing itself to the
fibres, or hemp, I find that these are generally less or more
injured, though not so much so, in my opinion, as to pre-
vent them from being excellent materials for making paper,

I have also found, and the importance of the idea will,
I hope, be an excuse for mentioning it here, that, though
the water, in which bean-straw has been put to steep, in a
few days generally acquires a black colour, a blue scum,
and a peculiar taste, yet cattle drink it greedily, and seemed
fattened by it. But my experiments have hitherto been on
too limited a scale to be able, in a satisfactory manner, toi
ascertain this last circumstance. When the water, in wbichfT

beat)

HEMP FROM BEAN 8'fALK8» S3W|^

be?an straw has been put to steep, becomes foetid, vhicb I-
find it is scarcely more apt to become than common stagnant
water, on beiiij^ stirred by drivinj^ horses or cattle through
it, by a stick, or in any other way set in motion, (as is the
case with all putrid water, even the ocean itself*,) the fetid '
particles fly off, and the effluvia die away.

When straw is to he steeped for bean hemp, the beans Mo<!e of

are to be thrashed m a niil) : the beans should be put to the «f ^'"'^'^"^^ **

^ bums.

mill, not at ri^ht anglesy but on a parallely or nearly so
with the rollers, else the stra<v, particularly if the beans are
very dry, is apt to be much cut. If the straw is not to be
steeped, on putting the beans to be thrashed at right angles,, •
or nearly so, with the rollers of the mill, a certain proportioa
of the fibres, or hemp, may easily be got from the straw,
these being in general not so much cut as the straw; but
often found torn off and hanging about it like fine sewing
threads. The hemp~thus taken off, though its lying under
water for months would do it no harm, requires only to be
steeped a few minutes, drawn through a hackle, and washed,
previous to its being l^id up for use. If the hemp or fibres,
collected in this way (which is a fine light business for
children, and such as are not able for hard work, and which
require^ no ingenuity,) are intended only for making paper,
they require neither steeping nor hacklings, but only to be
put into parcels and kept dry till sent off to the manufac^ '
turer.

The straw of bedns contains a sacchariiw? juice, and is Bean straw nn»
highly nutritive, perhaps more so than any other ; and like '"|\'^? •'"'^ ca-

11 • ri - • n pable of pro-

clover, the prunmgs of the vine, the loppings of the fig-tree, ducing a fer-

&c., produces a rich infusion, and uncommonly fine table- "^'^"^^^^^ **"

Quor.
beer, as well as an excellent spirit by distillation. It is the

hemp, or fibres, that prevents cattle from eating it. These,

like hairs in human food, make cattle dislike it. The coU

lecting of it therefore should never be neglected, nor the

boys and girls in workhouses and other places be permitted

to be idle, while business of this kind would evidently tend

both to their own and their employers' advantage.

It is a fact, that about the generality of mills for beating Refuse of

and dressing hemp and flax, a large proportion, in some ^!^\ *jf ^^^

H)land placets both of Great Britain and Ireland amounting^ terial for pu-

nearly P"'

BBMP FRO 91 REAV STAI.KS*

isearljr to otve half of wh»t U carried thither, U either Ief)t
th«re to rot, under the name of refuse, or thrown away as
of no use, because too rough and short for being spun and
converted ipto cloth. Now, from the experiments I have
fi^ tried, and caused to be tried, 1 have uniformly found, that,

though too rough and short for bei:ig converted into cloth,
ev«o of the coarsest kind, the refuse of hemp and flax, on
bemg beat and shaken, so as to separate the strawy from
the stringy particles, which can V>e done in a few minutes
hf a mill or hand-labour, as is most convenient, becomes
thereby as soft and pliable, and as useful for making- paper,
as the longest, and what is reckoned the most valuable part
of the plant, after it has been c6nverted into cloth and worn
fpr years.
Maybe made -^^ i^s natural, state, it is true, the refuse of hemp and flax
'•eiy white. is generally of a brown and somewhat dark colour. But
what of that? By the application of muriatic acid, oil of
vitriol, or other cheap ingredient, well known to the che-
mists, as well a<^ to every bleacher, such refuse, without
being in the least injured for making paper, can,, in a few-
hours, if necessary, be made as white as the finest cambric.
Number of There are, at a medium, published in London, every

i\ewspapers mornins:* 16000 newsparjers, and every evening about
poWvshedm s' i . » j a

London. J40<>0. Of those published every other day there are about

1,0000. The Sunday's newspapers amount to about 25000 ;

and there are nearly 20000 other weekly papers, making

Theseffon- in all the enormous sum of 245000 per week. At a ine-

sumeSCOtuns ^jypri c^q newspapers are equal to one pound — hence the

of paper aoitu- ^ , ^ , ^

a^y. wpole amount to about 3 tuns per week, or 200 tuns per

annum. But though this, perhaps, is not one half of the

paper expended in London on periodical publications, and

vyhat.may be called fugacious literature ; and not one fourth

part of what is otherwise consumed in printing-houses irx

the country at large ; yet there are materials enough in the

wfose of the hemp and flax raised in Britain and Ireland

fpr all thib and much more,

Ho-bines con- ■^"'* ^* ^^'^ '*^^^^ ^"*" ^^ ^^^ ^^"^ ^"^ straw of hops, a circum-

taia hemp, stance well known to the Society, contains an excellent

berap for inaking many articles, so also will it prove a moat

excellent material for naaking all kinds of paper. And it is

* fact.

I

HEMP FROM fiV.AV STALKS. 283

a fact, that, were even the one half of the bine of hops raised
in the counties of Kent, Sussex, and Worcester, instead of
being thrown away, or burnt, after the hops are picked, as
is commonly done, steeped for ten or twelve days in water,
and beaten in the same way as is done with hemp and flax,
independent of what mii>ht be got from bean-hemp, and a
variety of articles well-known to the Society, there would
be found annually materials enough for three times the
(quantity of paper used in the British dominions. .

1 have the honour to be,
with much respect.
Sir,
V Your most humble servant,

Sireatham, Jan. 9, JAMES HALL.

1809.

Certificates of the Truth of the foregoing Statement,
We, the undersigned, do hereby certify, ttat the spe^ii- Testimonies of
mens of hemp enclosed and sealed up by us, addressed to hem" from
Dr. Taylor, Secretary to the Society for the Encourage- beaahaulm.
ment of Arts, Manufactures, and Commerce, Adelphi,
Strand, are the produce of common bean straw :< — That we
never saw or heard of bean hemp till lately ; when the Rev.
Janies Hall, who resides here at present, was trying experi-
ments respecting it at Mr. Adams's farm. Mount Nod, and
Other parts of this parish: — That, in the present obstructed
state of commerce with the Continent, it appears to us the
discovery of bean hemf) may be extremely useful to the ma-
nufacture of canvas, ropes, paper, ^c. ; — And that, as it
affords a new and important prospect of employ jnent for the
poor, we think Mr. Hall, the discoverer, is deserving of the '
approbation of the public. We sha'll only add, that as the
Society for the Encouragement of Arts, Manufactures, and
Commerce, have contributed so often in a high degree to the
exertion of genius, the improvement of the arts, and the
public good, we have no doubt but they will not only take
the proper steps to prosecute the discovery and e)icourage
the manufacture of bean hemp, but also, by some mark of
their favour, show their approbation of Mr. Hall's merit in

^g^ HEMP FROM BEAN ITALKS.

the discovery I^e has made, as well as of his high public spi-
rit and liberality in coiiiinuuicatinu; the dibcovery to th<
public without reserve.

WILLIAM ADAMS, Mount Nod.
EDWARD BULLOCK, Curate.
Streatham, Surry, \VM. GARDNER, Surgeon.
Jan. 9* 180^.

it answer
tremoly Wi
foT sewing
$boes.

II

These are to certify to the Secretary of the Society for the
Encouragement of Arts &c., London, and all whom it may
concern, that havino^ seen (at first to our astonishment) the
Rev. James Hall, who has resided here for some time past,
procuring hemp fiona common bean straw, steeped yome days
in water, we steeped some also, and easily got hemp from it;
there being no mystery in the matter more than merely
steeping the straw, peeling off the hemp, and then washing
and cleaning it, by pulling it through a hackle or comb.

These are also to certify, that having tried bean hemp,>
and found it to take both wax and resin, we have sewed with
it, and find the fibres of which it consists in general so
strong, that the leather never failed to give way sooner than
the seam. We have only to add, that as hemp has of late
become uncbmmonly dear, while much of it is bad, weanxi-
oufily wish the prosecution of the discovery, and the appear*
ance of bean hemp in the market; and shall, so soon as we
hear of its being spun and on sale, be among the first to
purchase and use it,

JOHN HOUNE, Shoemaker.

THOMAS ALFORD, Shoemaker.

It bears
bleaching cx-
ticroely well.

Letter from Mr. Hume, of Long Acre, to the Reverend
James HalL
SIR,
I enclose a specimen of the bean filaments, or thread,
vvhich have been submitted to the bleaching process. The
texture and strength seem not in the least to have been im-
paired, but retain the primitive tenacity; and I am per-
suaded this subbtance will prove an Excellent substitute for
iiemp and fiax» for the ms^nufacture of various kinds of pa«

per.

AKX LYSIS OP SODALlW. §85

per, cordage, and other materials. I did not find more diffi-,
culty in accomplishing the bleaching of this than in other
vegetables which I have occasionally tried, and 1 believe thit
mrticle is susceptible of a still greater degree of whiteness.
I remain. Sir, ' \

Your very obedient ^ei-vant,
long Acre, Feb. 24, I8O7. JOS. HUME.

Letter from Mr. H, Davy to the Rev» James Hall.

SIR,

I shall giclose in this paper a small quantity of the beaa
fibre, rendered as white as possible by chemical means.

It seems to bear bleaching very well, and, as to chemical
properties, differs very little from hemp.

The question, whether it is likely to be of useful applica-
tion, is a mechanical one, and must be solved by experiments
•n itf comparative strength.

I am. Sir,

Your obedient humble servant,

H. DAVY,

vir.

A Chemical Analysis of Sodallte, a new Mineral from Green*
land. By Thomas Thomson, M. D. F. R. S. £., Fellow
of the Imperial Chirurgo-Medical Academy of Peters* ^

burgh ♦.

Jl. HE mineral, to which I have given the name of sodalite, Sodalite,anew

was also put into my hands by Mr. Allan f. In the Green- '"*"^'^'» !« ^^^
r J J I v>. *.v.i. compositioQ of

land collection which he purchased, there were several spe- a primitivtr
cimens of a rock, obviously primitive. In the composition '^°*'^'
of these the substance of which 1 am about to, treat formed a

* From the Transactions of the Royal Society of Edinburgh,
t See p. 47.

constituent,

£8)5 ATfALTWS OF SODAUTC.

constituent, ftnd, at first appearance, was taken for felspar,
to which it bears a very striking resemblance.
Composition This rock is composed of no less than five different fossiU,
* ^^ ' iiamely, t^arnet, hornblende, auj^ite, and two others, which
form the paste of the mass. These are evidently diHtrent
rotfierals; bnt in some s^>ecimen8 are ^so Hitimately blended,
that it required the skill Of Count Bournon to make the dis-
<!nmination, and ascertain their real nature. Even this dis-
tiui^uished mineralogist was at first deceived by the external
aspect, and considered the paste as common lamellated fel-
spar, of a greenish colour. But a peculiarity, which pre-
sented itself to Mr. Allan in one of the minerals, induced
him to call the attention of Count Bournon more particularly
to its construction.
Crystals of sah- On a closer examination of the mineral, Mr. de Bournon
* found, that some small fragments, which he had detached,

presented rectangular prisms, terminated by planes, mea-
suring, with the sides of the prism, HO" and 70" or nearly
so, — u form which belongs to a rare mineral, known by the
«nd of another name of sahlite, from Sweden. He farther observed, inter-
mineial mixed along with this, another mineral ; and after somie trou-

1>le, succeeded in detaching a mass, presenting a regular
rhomboidal dodecahedron. It was to this form that Mrp Al-
lan had previously requested his attention,
tesembling the Some time before this investigation, Mr, de Bournon had
Swedish natro- examined a mineral from Sweden, of a lamellated structure,
Wollaston. and a greenish colour, which, he foundj indicated the same
form. From this circumstance, together with some external
resemblance, which struck him, he was induced to conclude,
that our mineral was a variety of that substance.

To that substance the name of Swedish natroUte had been
given, in consequence of the investigation of Dr. AVollaUon,
who found that it contained a large propgytion of soda.
Natroliteof There are few minerals, however, thatiire so totally dis-

Kjaproih vefx tinct in their external characters as the natrolite of Klaproth,
different, ,11 • r» mi • 1

and the substance we are now treatmg oh 1 he mmeral exa-

iJiined by Klaproth occurs at Roegan *, on the Lake of Cori-

atance, in porphyry-slate, coating the sides of veins and cavi-

• It has been obserred also bf Professor Jameson, ia the floetz trap
/roclcft behind BurntUUnd.

tiei

^AKALYSIS, 9 F SODALITE. ggj

tii^s m a maraellated form, the texture of which is compact,
fibrous, and radiated ; the colour pale yellow, in some places
passing into white, and marked with brown zones. Hitherto
vit had never been found in a state sufficiently perfect to af-
.;|ie>rd any indications of form. Lately, however, Mr, de Bour-
non was so fortunate as to procure some of it, presenting ^
very delicate needleform crystals, which, by means of u
strong magnifier, he was able to ascertain presented flat
rectangular prisms, terminated by planes,which, bethought,
might form angles of 60° and 120 with the sidesof the prism.
With this neither our mineral nor the Swedish can have any
connection, farther than some analogy which may exist in
their composition.

Concerning the Swedish mineral I have not been able to
obtain much satisfactory information. There is a specimen
'40f itin Mr. Allan's cabinet, which he received directly fromi
Sweden, sent by a gentleman who had just before been in
London, and was well acquainted with the collections of that
city,, from which it is inferred, that the specimen in question
is the same as that examined by Count Bournon and Dr.
Wollaston.

Werner has lately admitted into his system a new mineral Fettstein
species, which he distinguishes by the name of Fettstein. Of
this 1 have seen two descriptions; one by Haiiy, in his Ta-
bleau Comparatif, published last year; and another by Count
Dunin Borkowski, published in the 69th volume of the
Journal de Physique, and translated in Nicholson's Journal,
{Vol. XXVI, p. 384). The specimen, called Swedish na«
trolite, in Mr. Allan's possession, agrees with these descrip-
tions in every particular, excepting that its specific gravity
is a little higher. Borkowski states the specific gravity of
fettstein at 2*563 ; Hauy at 2*6138 ; while 1 found the speci-
fic gravity of Mr. Allan's specimen to be 2*779, and, when
in small fragments, to be as high as 2*790. This very near apparently tlie
agreement in the properties of the Swedish natrolite with the s^^diJ^'j^^y^,.
characters of the fettstein leads me to suppose it the sub- lite. ' *

stance, to which Werner has given that name. This opinion
is strengthened, by a fact mentioned by Hayy, that fettstein
had been at first considered as a variety of wernerite. For
the specimen sent to Mr. Allanj under the nai^fi of compact

wernente^

Ago AVALTSIS OF SODALITE.

werneritpjifir obviously the very same witli the supposed ria-
trolite oi' Sweden. Now, if this identity be admitted, it wiTt
follow, that our mineral constitutes a species apart. It bears,
indeed, a coasideiable rtseu»t)ldn« e to il ; but neither the
^trystaUiue foriu, nor the consbtiients of fettsteio, as siated by
Haiiy, are bvniiiar to those of tlie mineral to which I have
given the name of sodalite. The constituents of fett»tein,
«» ascertained by Vauquelin, are as follows:

Constituents of Silica*..... •••44*00

Alurnin**. 34*00

Oxide of iron "^ 4*00

Lime ....... w .i •'•••*•••*'•'*... ... 0*12

Potash and soda* ••*•••• ......•• l6*50

Loss ••>. 1-38

100*00

I^escnption ol ^ §odalite, as has been already mentioned, occurs in a pri-
soUalite, mitive rock, mixed with sahlite, augite*, hornblende, and

garnet t*

It occurs massive ;j|nd crystallised, in rhomboidal dodeca-
hedrons, which, in some cases, are lengthened, forming six-
lided prissms, terminated by trihedral pyramicis.
**vlt« colour is intermediate between celandine and moun-
tain green, varying in intensity in different specimens. In
Bome cases it seems intimately mixed with particles of sah-
lite, which doubtless modify the colour.
' '. i. External lustre glimmering, internal shining, in one di-
-jre^tion vitreous, in another retinous.

Fracture foliated, with at least a double cleavage ; cross
-fracture conchoidril.

J, Fragments irtdetecminate ; usually sharp-edged.
Translucent.

Hardness equal to that of felspar. Iron scratches itwith
difficulty.

• This situation qf ihe augite fleserf es attention. Hitherto it has been,
vlth a few exceptions, found only in flatz trap roCks.

f Tlje particular colour and appearance of this garnet shows, that the
rock came from. Greenland : for similar garnet has irever been observed,
except in apeiimens from Grceftliftd, ■

Brittle.

ANALYSIS ON SOiJALITff. g89

Brittle.

Easily frangible.

Specific (gravity, at the temperature of 60°, 2*378. The
Bpecimen vvns not absolutely free from sahlite;

When heated to redness, does not decrepitate, nor fall to
powder, but becomes dark gray, nnd assumes very nearly the
appearance of the Swedish riatrolite of Mr. Allan, which I
consider as fettsteiu. If any particles of sahlite be mixed
with it, they become very conspicuous, by acquiring a white
colour, and the opacity and appearance of chalk. The loss
of weight was 2*1 per cent. I was not able to melt it before ^

the blow-|;)ipe.

1. A hundred grains of the mineral, reduced to a fine Chemical ana-
powder, were mixed with 200 grains of pure soda, and ex- ^*^^*
posed for an hour to a strong red heat, in a platinum cruci-
ble. The mixture melted, and assumed, when cold, a beau-
tiful grass-green colour. When softened with water, the

portion adhering to the sides of the crucible acquired a fine
brownish-yellow. Nitric acid being poured upon it, a coo;-
plete solution was obtained. '>i;? v

2. Suspecling, fkoni the appearance which the fused mflss
assumed, that it might coniain chromium, I neutralised the
solution, as nearly as possible, with ammonia, and then
poured into it a recently prepared nitrate of mercury* A
white precipitate fell, which being dried, and exposed to a
heat rather under redness, was all dissipated, except a small
portion of gray matter, not weighing quite 0*1 grain. This
matter was insoluble in acids, but became white. With pot-
ash it fused into a colourless glass. Hence I consider it as Siiexo
feilica. This experiment shows, that no chromium wad pre-
sent. I was at a loss to account for the precipitate thrown
down by the nitrate of mercury. But Mr. Allan having
shown me a letter from Ekeberg, in which he frefitions, that

he had detected muriatic acid in sodalite, it wp.s easy to see
thftt the white precipitate was calomel. The v/hite powder
weighed 9,6 grains, indicating, according to the analysis of
Chenevix, about three grains of muriatic acid. Muriatic aci<l.

3. The solution, thus freed from muriatic acid, being silex.
concentrated by evaporation, gelatinised. It was evaporated
nearly to dryness; the dry mass digested in hot water aci-

VoL, XXIX.— August, 18U. C dulated

^gO ANALYSIS ON SODALITE.

du.lat^ed with nitric acid, and poured upon the filter. The
powder retained upon the filter was washed, dried, and heat-
ed to redness. It weij^hed 37*2 grains, and was silica,

4. The liquor which had passed through the filter was
Supersaturated with carbonate of potash, and the copious
white precipitate which fell collected by the filter, and
boiled while yet moist in potash-lie. The bulk diminished
greatly, and the undissolved portion assumed a black co-
lour, owing to apme oxide of mercury with which it was con-
taminated.

5. The potash-lie being passed through the filter, to free
it from the undissolved matter, was mixed with a sufficient
quantity of sal-ammoniac. A copious white precipitate fell,
which being collected, washed, dried, and heated to redness,
weighed 27*7 grains. This powder, being digested in sulphu-
ric acid, dissolved, exceptO*22 of a grain of silica. Sulphate
of potash being added, and the solution set aside, it yielded

Alumine. alum crystals to the very last drop. Hence the 27'48 grains
of dissolved powder were alumina.

6. The black residue, which the potash-lie had not taken
TLip, was dissolved in diluted sulphuric acid. The solution
being evaporated to dryness, and the residue digested in hot

Lime. water, a white soft powder remained, which, heated to red-

ness, weighed 3*6 grains, and was salphate of lime, equiva-
, lent to about ^grains of lime.

7. The liquid from which the sulphate of lime was sepa-
rated, being exactly neutralised by ammonia, succinate of

Oxide of iron, ammonia was dropped in ; a brownish red precipitate fell,
wiiich, being heated to redness in a covered crucible, weigh-
ed one grain, and viras black oxide of iron.

-8. The residual, liquor being now examined by different
reagents, nothing farther could be precipitated from it.

9. The liquid (No. 4.) from which the alumina, lime, and
irori had been leparated by carbonate of potash, being
boiled forborne time, let fall a small quantity of yellow-
coloured niatter. This matter being digested in diluted
sulphuric acid, partly dissolved, with effervescence; but a
•portion rerfiained~undissolved, weighing 1 grain. It was in-
solubk in* acids, and with-potash melted into a colourless
Sttex. glass. It was therefore filica. The sulphuric acid solution

.V V . '' being

being evaporftteci Id d'^yri^s^, kft a i*esidu^, tvhicfh ^ofTeifed

the pro|)ert»es of sulphate of lime, and which weighed 1»2 Lime.

grains, equivalent to ahoutO'7 of a grain of lime.

10. The constituents obtained by the f>rec^ding analysis Analysed in a
Leins^ obviously defective, it remained to examine whether *^'^^^'*^^^ '^*^*
the mineral, according to the conjecture of Bournon,
contained an alkali. For this purpose, 100 jj^rains of it, re-
duced to a tine powder, and mixed with 500 grains of ni-
trate of batytes, were exposed for an hour to a red heat, in
a porcelain crucible. The fused mass was softened with*
water, and trt-ated with muriatic acid. The whole dis-
solved, except "id grains of a white powder, whicKp^jpOved
on examination to be silica. The muriatic acid solution
was mixed with sulphuric acid, evaporated to dryness;
the residue, digested in hot water, and filtered, to sepa-
rate the sulphate of barytes. The liquid was now mixed
with an excess of carbonate of ammonia, boiled for an
instajntor two, and then filtered, to separate the earth and
iron precipitated by the ammonia. The liquid was evapo-
rated to dryness, and the dry mass obtained exposed to a
red heat in a silver crucible. The residue was dissolved in
water, and exposed in the open air to spontaneous ev'pora-
tion. The whole gradually shot into regular crystals of
sulphate of soda. This salt, being exposed to a strong red
heat, weighed 50 grains, indicating, according to Berthol- s^^la
let's late analysis, 23*5 grains of pure soda. It deserves to
be mentioned, that during this process the silver crucible
was acted on, and a small portion of it was afterward found
among the sulphate of soda. This portion was separated
before the sulphate of soda was weighed.

The preceding analysis gives us the constituents tjf soda-"
lite as follows:

Silica, - 38'^^ r^ ^ ... _>

Lime, 2-70

Oxide of iron, l-OO

Soda, 25.50

Muriatic acid, 3-00

Volatile matter, ^^JO

Loss, 1-70

lou-00

2^$ PRIMITIVE GYPSUM.

Analysis by ]\f f. Allan sent a specinien of this nnineral to Mr. Ekc-

Mr. Ekeberg. , , i i • . i r i mt

berg, who analysed it in the course of last summer. The

constituents which he obtained, as he states them in a letter

to Mr. Allan, are as follows :

Silica, • 3f>*

Alumina, • 32*

Soda, 25.

Muriatic acid, 6*75

Oxide of iron, • 0*25

10000

V Thi« . .suit does not difFtir much from mine. The quan-
tity of muriatic acid is much gre'citer than mine. The lime
and the volatile matter, which I obtained, escaped his no-
tice altoo^ether. If we were to add them to the alumina; it
would make the two analyses almost the fame. No mine-
ral has hitherto been found containing nearly so much
soda as this. Hence the reason of the name by which I
have distinguished it.

VIII.

Account of a Primitive Gypsum, By Mr, Dausuisson,
Mine Engineer*,

»,n'[f; Ji"«,?r, ^"* An a visit I have iust made to the mine of Cogne, I had
inuiTe gyp- ** .

sum. an opportunity of observing a mineralogical fact, that may

be thought not uninteresting, the existence of a stratum of

primitive gypsum, intercalated in the mass of the Upper

OrJy one pre- xXXi^, Mineralosrists have hitherto noticed onW a single in-
vious instance,. ^ . ,° ,. juatt^iu

stance of such gypsum, discovered by mr. t^nesleben at

the southern foot of St. Gothard in a micaceous schist ; and
and this 8ome doubts have been started respecting the period as-

signed to the formation of this rock. I trust the particulars
I shall relate respecting the situation of that at Cogne will
evince the existence of really primitive gypsums; accord-

* Journal des Mines, vol. XXII, p. I6l.

ingly

PIIIMITIVE GYPSUM. "^^3 -

iri^tyf shall begin with'a iTeWNs'or^s on the mineral con-
stitution of thetountry around.

The southern declivity of the Alps, from Mount Blanc Southern de.

to Mount Rose, belono-s almost wholly to the micaceous ^j'/''^ ^^^^*^
' s» •' _ Alps.

schist formation. Here, as in other places, this schist fre-
quently includes strata of primitive limestone, serpentine,
chlorite, oxidulated iron, &c. Sometimes it passes into
argillaceous schist, as at the col de TAllee Blanche for in-
stance ; but still more frequently into gneifs and granite.

About 15000 met, [9 miles] south of the town of Aoste, Mountain near
and to the east of the village of Cogne, which is at its foot, °S»«»
rises a mountain, that forms part of the chain separating
the valley of Cogne from that of Fenis« It is terminated by
a sharp ridge at least 700 met. [765 yds.] above the bottom
of the valley. Its absolute height appears to me nearly to
equal that of the passage of the Great St, Bernard, or
2400 met. [2623 yds.] above the level of the sea, It pro-
bably rests on the granite, that shows itself on the Surface
2 or 3 kilom, [10 or 15 furl.] to the north. It is composed
of micaceous schist, in strata very slightly inclined, so that
they may be considered in general as horizontal. In its
upper part the micaceous schist becomes loaded with lime-
stone, so that in some little places it ends with being nothing
but a white granular limestone containing merely a few
spangles of mica. It includes also considerable strata of
serpentine, in one of which is the celebrated iron mine of
Cogne*.

T!ie stratum of gypsum is found 20 met. [23 y<is.] below stratum of
the highest point of the ridge. It is exposed only to the gypsum.
length of 7 or 8 met. and 1 met. thick. Throughout the
rest of its extent it is concealed by the numerous fragm«fnt3
of stone, that have fallen from the sumflriit, and cover the.
aides of the raoi:^ntain in this part : so that I can say nothing

♦ This mine, perhaps the richest in the world, exhibits the appearance Rich iron
of an iron quarry, which is worked in open dr.y. The ore is oxidu- mine,
lated iron, in some places pure. It is in fery small grains, and some-
limes wholly compact. It forms a mass, that appeared to me to be a very
short and thick bed. Where it is worked it i« more than 25 met. [27
yds2 thick,

of

^54 PRIMITIVE GYP8USI.

Cf its length, thickness, or th^ circumstances of its super-
position. However at move than 50 met. beyond the place
'Vfrhere it has been laid open for working 1 have seen indi-
cations of its existence. It^ thickness cannot be great,
for the rock appears in its natural position a few yards
jptlow the place where it is worked. The rock at this place,
9s well as above the straiuno, is a micaceous and calcareous
jchist, of a deep gray, with plane laininse, traversed by nu-
merous filanients of calcareous spar, and including some
veins and nodules of quartz. In getting out the gypsum
the workmen have advanced about two yards under the
$chist, so that this rock forms a projecting rooT, under which
they work. In this place we see in the most distinct man-
ner, that the schist overlies the gypsum : both are strati^,
fied : their strata are perfectly parallel, and dip only a few
degrees to tlie south-east. The strata of gypsum are a few
centim. [the cent, is ne:ir 4 lines] thick, and frequently se-
parated from each other by u greenish talcy coal.

Tbegypsuoj fj^Js gypsum is of a fine white colour, with sometimes a

described, .,""'• , n n • -i

1^1 1 ght rosy tinge, its grain is very hne crystalline, smiuar

io that of the beautiful Carrara mai'ble. It is very trans-
Uicid, and very soft. If pieces of any size, and exempt
from fissures, could be got from the quarry, it would form
^ very tine alabaster. It is uspd however for building, and
ipakes good plaster.
Talc contained It contains a great deal of talc in detached particles, ge-
^^ ^^* neially lenticular, and varying in size from that of a lentil

to that of a walnut* These almost always lie flat, and ar-
ranged in lines parallel to each other, and to the stratifi-
cation. Their colour is a very pleasing green. Sometimes
the laming of talc are so close together as to produce a
kind of steatite ; i^ometimes they are very narrow, resem-
bling fibres, and forming together littje masses, ^'?ihibiiing
.8 pleasing variety of fibrous talc^ , Pretty frequently these
isbies are disseminated in small groupes through the gyp-
sum, are of a delicate light green, and might be taken at
first sight for amianthus, of which they have all the apr
pearance. Martial pyrites also is seen in the gypsum, and
particularly in the small masses of talc. It is sometimes iq
founded grains, sometimes in little striated cubes.

What

ON THE rRUCTIFlCATION OF. THE FIRS. 2^^ -

What I have said, particularly on the par?illel strQtifi(;a-'Of the same
tioa of the gvpsum and micaceous schist, as well as on the l^^^}^^ (^^ %
presence of the talcy orsteatitic matter ip thei^e two mine- rocks.
ral masses, evidently shows, that they.:are of the same for* :
mation, that is, formed at the same period. The nearly ho-
rizontal position of the strata from tlie foot of the mountain. '
to its summit; the identity of the rock, that forqas the roof ,
and the wall of the strata of gypsum, &c. ; all militate against ^.
the idea of a transposition, that might have covered a second- a
ary gypsum, deposited on .the mountain subsequent to it^.
formation, with a block of schist. Here the gypsum is really
a component part of the mountain ; it is one of the courses,
that form the building; and it has ever been placed before '
several others, those that are at the summit. Now the moun- .
tain of Cogne itself makes part of that portion of the Alps,
GrandiAlpi of the Italians, which extends from Mount Blanc .
to Mount Rose: and it is of the same nature, as we may be
satisfied by reading what Saussure has said of that countrji;^
in his journey to Mount Cervin. Thus we have a gypsum -s^ j , '.-.t
of the same formation with those lofty mountains, which ^ s .mir,^ns>r.
have always been considered as primitive, or anterior to the
existence of organized beings, and which every thing still in-
dicates to be so.

IX.

Farther Observations on the Fructification of the Firs» In «i
Letter from Mrs, Agnes Ibbetson.

To Mr. NICHOLSON.
SIR,

.y endeavour to contract my subject has made me leave
out much respecting the firs, 1 think of high consequence ^^^ of the
to them : I shall therefore add this short letter respecting
the cones, that I may not be misunderstood.

I have said that the seed of the fir is not impregnated the
first year, and this is certainly true with respect to the pin«, "°je*^j^7Ir5t
and all those yfr«, the male flower or catkiD of which so much year.
>j,,,:j,r}'hr-.'- ■■'^^'- ^precedes

255 OW THE ?RyCTinCATIOK OP THE FIRS.

precedes the female cone, as to disappear wholly before the
Scotch £r. pistil is scarcely visible. The Scotch lirwill serve as a pro-r
per example. The female cone for the present year came
QUt in June, 1811. In May, 1811, all the powder of the
^tamens had disappeared ; besides that the cone shows no
-seed till full three months after its first coming, of course
these seeds could not be impregnated. !Next year, May 1812,
the cone will show (by many outward si^ns) that the seed is
ready to receive the line of life; the pistils in the cone will
be elongated ; the drops ready to be saturated with the pow-
der of the stamen as soon as it is fit. The pistil is then in
the (?xact situation in which 1 drew it in my last letter;
and the impregnating and nourishing vessels distended in a
manner they never are but at this time. As soon as the
drops are saturated, the pistil draws in, and all is complete
for the year, except that the cones continue to increase and
alter their form by degrees. The followinj^^year, March 1813,
they will beoin to swell about the y)oints, an<l in a \'^w months
to open ; and this is the time the cones in England are
obliged to be gathered, or they are very apt to shed their
seed. Still they areyjir /oo wucA attached to their stalks;
and are often greatly hurt by this early plucking. 1 be-
Foreign seed lieve it will be acknowledged that now, as well as in Evelyn's
of pinea best, ^j^^^ ^^g ^^^^ ^f ^H pines arp/ar better coming frorp abroad,
than that shed in our own country : and the reason is plain :
they are able (from the shade either of the mountain or the
forest where they grow) or from the northern climate, to rer
main on the trees till ripe; so that they are not gathered till
the fourth or fifth season. That is, if appeating in |8ll,
they are not sent to this country till 1314 or 1815 : by which
means, the integuments will be completely loosened from
the tree, (not torn as ours are), their seed will be perfected,
and fiill of moisture; and if in taking out the seed some in^
jury is done to the vessels, it signifies little, as the process ig
completed : but in ours, when the seed is but half formed,
to injure the vessels is to stop the completion of the seed,
a«d this is the exact difference between the two sorts when
exannned: the work of Nature is finished in the foreign
seed ; in ours \i i? not perfected. No person, who is not o,

dijfe^ior^

ON THE FBUCTif KATIOK OF THE, F1119..- 297^

diJJectoTi can conceive the mischief done to such seeclsj Jpjj^
thus tearing the chief vessels in the cone. , .\ ,> - .^

In tht pines it is most easy to know the cone of the year Cones of the
for several vears back, as they ave always found on the year's P'"® °^ ^'*^*

•' 111 '^^^^ ye^ra

shoot to which they belong. By traongeach shoot the tree growth de-
has made a few years back, this will be found 7itf!;6T /o rary.^cribed.
The first year's cone w white and close ; thi^ s^ond year's if,
green and close ; the thnd brown; the fourth bi'owjpi, dod-
open ; and each falls back one year's shoot. '„.«

With respect to the larch, it is very different ; in Aai^i/, Fructification
nature^ and appearance, no trees can differ more. The larch. "^*^^^ larch,
gives her fruit in an irregular manner, equally on the old as
on the new wood. It has also its ft-male catkin appearing
biifoie the male, and so much preceding it, that the seed Jft
ready for impregnation, ere the powder o^* the stamen i*
ripe: this is easily known, by dissecting the cone of the' /a5^
year^ and comparing it with the present. /Jlie distended
vessels, which are most observable »t the ba<!:k ; the ppeaio^
of the nourishing vessels, and above all the bubble, i£
watched for in April or May, prove this'^early impregnatioij-
1 doubt not it is also the case with the cedar of Lebanoii^ Cedar of Leba-
though the cones oTthis tree hang afterwards till the foortti '^""'
or fifth season, as their appearance testifies. The quantity ,|^^»* g^j^,,,;^
of tannin (or of that juice which appears to contain it), is Tanftin."' i '■'
excessive, and seems nearly as. much as is contained in the
bark ; for the cone pdrt (when the seeds are taken out) y. if
magnified, shows nothing but bladders of this juice. ;: \

As to the cypresses, and those I have ventured to i:anU Cyprc§s€s.
with them, (like the pinesX th^ey ar^ too late in thf> ye^sr fq^
impregnation; beside that the seed i? 43oV.!ibrp[|ed^,Ortl^
cone opened, till late in the autunnnf • ; ' r .,? - ..

Since I have turned ray mind to remark the quantity of Quantity of

tatinin found in tr^'es, 1 have observed how much more ig tanmn m dtffa

rent trees,
found in many, than in the oak. In the b^tvjla alnus of

this country there is certainly a very great quantity, though

not so much as in the firs.. The men's hands who bark it

are always so stained, that they find it very difficult to obii*

terate it; which is not the case when they strip the oak.

Affer studying the firs, my hands were so stained, I had

^reat trouble to take it from them ; and yet the guarding,

tcoo^

5{M SCRI^W ADJU&TIN6 FtOUGB.

v^ocid of the firs is of a beHutifu) j-eliow white, till exposed
to lb€ air> when it becomeis a deep brick red.
I am, Sir,

Voiii* obliged servant,

AGNES IBBETSON.

Description qf a Screw adjusting Plough ^ invented hy Mr,
Thomas Balls, of Saxlingham, near Holt, Norfolk*,

SIR,

f|ov»li on a J[ HUMBLY offer, for the inspection of the Society, the
^^^^ model of a plough, constructed upon a principle on which I

have made itHveral.

Sir Jacob Astley, Bart., has seen two at work on nay farm,
which I have constantly used, in different kinds of plough-
ing, for three years, and which, excepting in the share,
hare not cost me a shilling in repairs* Sir Jacob has or-
dered one to be made; and he being desirous, that the
plough should be more generally known, expressed a wish
that i would send a model to the Society. If its mecha-
nical principle proves to be of real utility to agriculturists,
and superior to the ploughs in general use, I shall be highly
gratified in my endeavours to promote the liberal views of
the Society.

I am. Sir,

Your most obedient humble Servant,

Sarlhgham, April 5, ISIO. THOMAS BALLS.

Certificate from Sir Jacob Heney Astley, Bart.

BEAR SIR,

Tesrtnrm of T have seen Mr. Ball's plough worked against the com-

its uiiliiy. ^^^ Norfolk plough, and find it much superior. It laid the

furrow rauqh better, more equal, and with much less draught

• Trans, of the Soc, of Arts, Vol. XXVlII, p. 45. The silver jne-

dai was voted to Mr, Balls for this invention. ' - • i*'

to

SCREW ADJUSTING PLOUGH. 299

to the horses, and has not wanted the usual repairs, which
the common ploughs are subject to, I make this observa-
tion from having had one in use for more than a year ; and
I find this plough much approved of by the farmers in this
neighbourhood.

1 remain. Dear Sir,

Your most obedient Servant,
Milton-ConstahU, May 3, IdlO. J. H. ASTLEY.

SIR,

The enclosed certificates will, I hope, be satisfactory to Advantages of
the Society respecting my plough. It is a material improve- * i? ° 8 •
ment over the wheel-ploui^h in commoa use in Norfolk, as
it works with greater ease to the horses, on account of the
line of draught being on a line with the angle of the horse's
shoulders. It lays the furrow-slice particularly level, and
cuts an even bottom-furrow. It is less liable to wear, on
account of having less friction on the ground irons. It is
particularly well calculated for breaking up stiff old land,
and less liable to be put out rtf order than any plough ge-
nerally used. By the adjusting screw, the furrow may be
set from one to nine inches in depth, and secured by a lock
to any of those intern^ediate depths with the greatest exactr
ness. It may b& easily converted into a swing-plough, by
disengaging the axle-tree and wheels. Its beam may be
mad^ particularly light, on account of the hue of draught
lying so near the heel. I beg leave to inform the Societ}',
that the Earl of Thanet, in the year 1807, ordered two of
these ploughs, and in 18Q9 six more of them. Mr. Bur- Misuse adopted
roughs, of Weasenhara, intends to have all his ploughs on - ^^^^^* •
this plan; also Mr. Wall, of Bayfield-lodge ; Mr. Cobon,
of Leatheringsett, will have two ploughs; and the Rev. T.
Munoings has given orders for some to be made.

If I had not been so limited in time, I could have sent

yoi? m-^ny more certificates,

I am. Sir,

Your most obedient humble Servant,

THOMAS BALLS.

Scxiingham, May 6, IS 10.

Certificates

3G0 SCREW ADJUStlNti VLOtjfen.

farilier tcsti- Certificates were received from the following persons : viz,
Mr. Robert Wright, of Great Snoring, stating, that he has
three of Mr. Ball's ploughs, which he conceives to be much
superior to the common plough, both in the execution of
the work and easiness of draught,

Mr. Mark Barret, farming steward to Sir George Chad,
stating that he has three of Mr. Ball's ploughs; that they
are the best he has ever made use of, and answer every pur-
pose, both as a swing and wheel-plough.

Mr. Thomas Hurreil, of Saxlingharn, stating his opinion,
that Mr. Ball's plough will come into extensive use, being
an excellent plough for general purposes.

Mr. Henry May Waller, farming steward to Sir Jacob

Henry Astley, Bart., stating, that he has two of Mr, Ball's

ploughs in constant use ; that he thinks them well calculated

, for strong work ; and that they may be converted into a

,. swing-plough, by disengaging the wheels.

«»

Rffsrence to (he Drawing of Mr, Bail's Plough, fig, 1,
P/. VIII.

D?^;crrition of ^ ^^ the beam of the plough carrying the coulter B,
the piougb. share D, and handle E ; F is the mould board ; the draught
of the plough is taken by two iron rods G, connected at
one end with a hook a in the beam A ; and at the other
with an iron bridle H by a swivel-bolt; this iron bridle
has several notches to receive the draught-chain I, by
means of which the point of traction is adjusted sideways;
the adjustment for height, and in which the improvement
consists, is made by an iron frame K, at the top of which
a nut is placed acting upon a screw d fixed into the beam A;
the axletree e of the wheels J'f is connected with the iron
rods G, by a single bolt or pivot projecting from the end of
them, which passes through the axletree; by these rowans
the wheels always apply themselves to the inequalities of the
ground without iniluencing the motion of the plough. The
nut of the screw d, being turned, raises or lowers the iron
rods G, and elevates or depresses the point of traction, so
;^hat the plough will cut a greater or leas depth of furrow.

XI.

IMPLEMENT FOR EXTIRPATING D0CK9. AND THISTtBS. 501

-xr. , . ■

An improved Lnplement for extirpating Djeks and Thistles;,
by Mr. J. Baker, o/" West^Coker, near Yeovil, in Svmefr\_
set shire*.

SIR,

Jl HAVE sent to the Society an implement of my inv^n- Implement for
tion for destroying? thistles and docks, which are tv»'o ^'^^y*"" thSes'a^d
jurious weeds to agriculturists. docks.

The implement is so contrived, that, if the root breaks in
the claw, in attempting to draw it, you may, by turning the
instrument, cut the root so far below the turf as to prevent

its growth.

I am, Sir,
Your obedient Servant,
Wcst'Croker, Oct, 31, JOHN BAKER.

1 809.

Certificate.

We do hereby testify, that the instrument made by Mr. Testimonies of
John Baker for destroying docks and thistles has been used ^^* "^^'J^y-
to great advantages and is likely to come into general use. — -
Edward Guppy, Nathaniel Bartlett, Thomas Sandfwd,
Edward Penny.

Description of the Implement,

Fig* 2 of PI. VIII represents Mr. Baker's thistle-extir- The Jmple-
pator. A is the handle; B the claws, between which the '"t"' ''""
thistle is received ; the curved iron C is the fulcrum, over,
which the purchase to extract the weed is obtained; D is
an iron rod, or bar, upon which the foot is. placed to thrust
the claws into the ground. In case the root of the nveedy^
breaks in endeavouring to extract it, the curved blade %y:i
which has a sharp end like a chissel, is thrust into the^
ground to cut off the root of the thistle some inches below .
the surface, and prevent its vegetation. ^. » ;

* Trans, of Soc. of Arts, vol. XXVIII, p. 50, The gold medal was
toted to Mr, Baker for this inreniion.

Description

302 EXPANDING HARR0W8.

XIT.

Description of a Pair of Expanding Harrows, appUcahle
both for cleaning foul Land, and harrowing in Seeds. By
Mr, AViLLiAM Jeffery, of Cotton-End, Northampton*.
SIR,

New invented -IL HAVE sent, for the Society's inspection, a model of a
harrows. ^^\^ of harrows of my own invention, made to a scale of one

inch and a half to a foot, and which are allowed to be a
great improvement in these implements.
The improve- The improvement consists in their power of contraction
or expansion, so as to cover an extent of land from five feet
to ten feet; their teeth may be set at twelve different dis-
tances between them, and their tracks will always be at
equal distances, according to the state of the land ; they
will either servefor harrowing in seeds, or cleaning foul land.
For cleaning foul land this harrow far exceeds any other
yet made; for in such land the teeth ought to be at a
greater distance in the first harrowing, and at the subse-
quent harrowings to be brought nearer together by degrees,
till the teeth are brought very near together by contracting
them. One pair of my harrows ansiver the purposes of
three or more pairs made upon the old construction with
fixed teeth.

My harrows are so constructed as to be contracted, or ex-
panded, in two or three minutes; and the teeth, which are
thirty-four in number, set at any equal distances required,
having only two screws to confine them. This implement
is more durable than other harrows, as there are no
mortices or tenons in them to weaken the wood-work, or
admit the rain. Theyare puttogether with iron nuts and screws.
They are also easier conveyed from field to field than
other harrows, and when not in use will fold up in a
small <?ompass. I hope they will meet the Socfety's appro-
bation, and be rewarded according to their merit.
I remain. Sir,

Vour humble Servant,
Cotton-End, Northampton, WILLIAM JEFFERV.

June 8, I8O7.

♦ Tnuii. of Sec, of Arts, vol. XXVllI, p. 51. The silver mfdal was
▼oted to Mr. Jeffery.

On

VARIATION IN THE STATE OF THE HAIR. SOS

On the 3l8t of March, 1810, certificates were received T««ain4omesrf
from Mr. John Rice, Cotton-End; Mr. J, Hawkins,
Castle-Ashby ; and Mr. William Shaw, Hardin g^stone, to
the following effect : viz. — That they Ivad purchased of Mr.
William Jeffery, and nnade perfect trials of his newly-
invented expanding harrows, and find them to be upon a
tnuch superior principle to any they have seen, or made use ,'^

of before.

Reference to Mr. W. Jeffery's Expanding Harrows.

Fig, 3, PI. VIU, represents Mr. Jcffery's expanding bar- The !^imnr
row. It consists of two sets of movable bars of wood, con- ^*^
nected by hooks in one set, and eyes in the other. Each set
is composed of four bars of wood, A B C D, furnished with
teeth; these are connected, and held parallel to each other
fey three other bars, or braces, E F G, united to the former
by screw bolts ; the iron loops H I are the points for the
chains, by which they are drawn; K are two iron braces,
joined to the bars E at one of their ends, and have a nutn*
ber of holes, any of which can be put over screw-pins fixed
upon the middle bar F, provided with nuts; when these
nuts are removed, and tlie iron braces detached from their
pins, the frames may be either closed up, or extended, so
as to bring the teeth of the harrow nearer together, or Te-
ttiove them farther asunder, and they, can be fastened at any
point by the different holes in th6 irOn braces, so as to be
worked with the teeth at any requisite degree of extent.

XHI.

Observations on an occasional Increase and Decrease of
Bulk in the Hair of the Head. In a Letter from Tho-
mas FORSTER, Esq,

To Wm. NICHOLSON, Esq.
SIR,

At has always appeared to me, that the best means to get Knowledge
Sit a correct knowiedge of any intricate subject is, to excite e*'"*^ *»y«*-

the

304 VARIAXroiJ IN THE 8TATB OF THE ni»*

dtingatten- the attentiort of others toward it; particularly of those t^ho
tjon loasub-. j^^.,y have more extensive opportunities, as well as more ca-
pacity for accurate observation than myself. In confor*
mity with this view of the subject, I request your insertion of
the following observations.
STmpat1i> be- The sympathies between theskin and tjvestmnach have been
^TduomLt'" frequently adverted to by physiologists ; the skin hafr lieeii
found to be alternately hot and dry, hot andmoisty cold and dry,
and cold and moist \ and thest' vaiietiet- have been attributed
to variations in the»state of the stomach, between ^*hich and
the skin a very direct sympathy is believed to exist. But
the variations in the appearances of the hair do not appear
to be duly noticed. ,

Variations in ^ \\iS.ve remarked, that people of what is usually called ner*
the appearance yous and susceptible constitutions appear at times to have but
half the quantity f>fjiai r on their heads, that they have at others.
Causes of ap- though they have assured me none had been cut or combed off.

parent m- q^^ minute examination I have found, that the apparent in-
crease of quan- ^ ^
tity. crease in quantity at certain times was occasioned by the fol-
lowing circumstances: the shafts themstlves were found to be
The body of specifically larger, and more tense or elastic, at the same
br^wi!'^^"* time that they did not lie in such close contact. The ap-
parent diminution in quatitity, at other times, I found to
res^ilt from a specific decrease in the size of the shafts^
which also lay in closer contact than ordinnry, and were
more flaccid, and g««era{ly more dry, ConBidering the
considerable influence which the atmosphere" exercises on
our bodies, I was once induced to attribute the closet con-
tact of the shafts to a diminution in their electricity^ by
which they would become less mutually repulsive \ this hcw-
evtr does not seem calculated to account fot their increase
What is the in size. May the shaft be considered to be organized
Museoftbis? tbroj^fjhoiit, arvd itt<- eulargem.eut to be ca«s\;d by an in-
creased action of its vessels ? or. Is tHere an aeriform pers-
piration into the cavity of the shaft, on an increase of which
it becomes distcirded ?;or may the increased tension and
size of the shaft be considered as resulting from the coope-
ration of these two causes ?
Apparently T^^* strength and tension of the hair appear* generally Ui
eoiJaected accGmiwmy beftlth, -while the weakness, close contact, and

flaccidity

K.~.

I>reyenti6n of dakaqe by lightning. 305

flaccidity of it denote disorder T have observed also, that with health
small doses of mercury liave changed, the appearance of the j^Jeiciuv «ion
'Ihaif very soon aftertheir admiuistrotion. Froiti being flaccid, restores the
dry, and small, it has becouie tense, stroma, and moister; ^^^^'^^^ ^?*
at the same time mode tension and solidity has appeared in
the muscles, and the countenance has displayed a more
healthy appearance. Now mercury may increase an aeri-
form perspiration, (if such a oneey.ist) into the shaft ; it n^ay
also set thedii^estive organs to rights, thereby cause a more
healthy action of the vessels in general, and of those of the
shaft among the rest. I cannot help observingi that there is
no objection to supposing hairs organized, because we can- Organization
eannot discover their vessels. On this subject we may, I Jendrmubh*
think, be allowed to reason thus: If all nourishment be farthenhan is
performed by the action of vessels, either vascularity must p^^^J^^^ ''"^"
extend itself rtc? in/?wi/«m, or there must be certain small
vessels not nourished at all. Can we demonstrate those
•mall arteries, which ramify iti the coats of and nourish the
smallest vasa vasorvm} Such considerations as these
ought to prevent our denying organization to any part of aa
animal body, even to the cuticle and the enamel of the teeth.
I fihall be much obliged to any of your correspondents,
who may have notic^ any connection between the varieties
in the appearance of the hair and any peculiarities in the
state of the body, &c., to communicate them in your scien*
tificjournal; and I remain, Sir,

Your constant reader,

THOMAS FORSTER.

XIV.

On the Prevention of Damage by Lightning. In a Z^ettet

from Mr. B. Cook.

To Mr. NICHOLSON.

MY DEAR SIR,

A HAVE read with much concern almost ev^y week for Annual <!i^
some time past accounts of some damage of one kind or other ^^.^^ ^one'itt
done to buildings, trees, and cattle, or in the loss of lives by iigntninff/^
Vol. XXIX,— August, 181 1. X lightning;

306 rEEVENttON QF b^MAGE BY tIGHtNINfl.

lightning; indeed every year this country suffers very much,
either by the destruction of trees, houses, and cattle, and
what is far more distressing, the loss of so many lives by
the electric fluid. I have endeavoured to form an idea of
the loss sustained on an average; and I iind upon a mo-
derate calculation, it cannot be far short per annum of 40 to
50 thousand pounds, and the loss of lives from 20 to 30«
It is of so serious a nature, that I wonder no effort has
been made to remove, if not wholly, at least a part of the
evil. Looking at it in this light, and conceiving it to be
.the duty of every man to endeavour to propose some re-
medy, 1 have taken the liberty to hand you what follows
for your consideration ; if you think it worth inserting in
your valuable Journal.

Our kingdom from its high, and rocky nature, from its
bowels containing such vast masses of iron, copper, and
other ores, all concjuctors of lightning, and also from its
situation in the midst of the. waves, itself becomes a con-
ductor also; all these circumstances conspire to collect the
electric fluid together around us. If it was possible to find
out means to carry off this very destructive element
without danger, the country would experience a great and
invaluable benefit from it. The loss of so many lives is a
very serious consideration, and ought to engage the studies
of the philosopher and philanthropist to propose some re-
medy, if only for their sakes, and if it is impossible to re-
move the evil wholly, at least it is possible to remove it
' partially.
Plan proposed The plan I with much deference propose, and I feel sa-
fer preventing iisfaction in proposing it first to you for your consideration,
because if you do not approve of it, it will not meet the eye
K)f the world, for no man is more competent to decide upon
its merits than yourself. The. plan is to erect at different
stations conductors throughout the kingdom, at 5 or 6 miles
jdistant, or in some instance nearer, according to the nature
dofthe ground, on the most elevated parts, so that wherever
^the clouds moved, surcharged with the electric fluid, the
conductors would carry it down, so that it would be next to
A«vimpossibility for a collection of electric fire to accumu-
h;te| s© «s,^P produce *,d€iittwiti_yje di§(^liarge. I have very

• '■. •■^" ' ' ■ ' ■ ';^;;" ■• - - • little

PEEYENTION OF DAMAGE BY LIGHTNINO* «Q7

little doubt, but that all, or nearly all of the fluid would be
carried off bv these conductors, and little or uo damage, or-
<3eath would erer be occasioned by the lightning.

The expense of erecting conductors at different station*
throughout the kingdom would be saved in a few years,
and the safety of men's lives would be of more value than
any expense that could be incurred. If every parish
would agree throughout the kingdom to appropriate a part
of the rate for the erection of 4, 6, or more conductorss, ac-
cording to the size of the parish, on the different parts that are
most elevated, the expense would not be felt — indeed it
would not be worth naming. If the different noblernen,
gentlemen, &c., of the different parishes were lo tnke it into
consideration, first considering the certain security it would
provide for their cattle, buildings, and the lives of them- .
selves and servants; and secondly, when they estimate the
very small expense these conductors might be erected for ;
I do think every parish wo.uld instantly be induced to adopt
the plan.

But there are several great imperfections and objections Faults of the

against the present iron conductors. common iron

, . conductors.

The first is, the very short time they stand without being

deeply corroded with rust, and when first put up the iron is

so very irregular on the surface, that it is a great hindrance

to the descent of the electric fluid, and calculated in a

great measure to cause it to fly off to any other conducting

substance in its way or near to it; and when up for a feiv

years it becomes still worse, and so incrusted with rust, that

the irregularity and imperfections of the conductor are in*

creased. Another fault is, that the tops of the conductor*

are not raised high enough above the building they are

placed to protect; the point of the rod is in general placed

just above the chimney. The rod ought to rise 6 or 8 feet

above the top of the house or building, and to end in a

single point only. If conductors are used, in every instance

the best materials should be used to make them. Iron is

the very worst material, and yet all conductors are made of

iron ; but this arises from the cheapness of the article.

According to the experiments of Mr. Henly, (published Conducting

Un Dr. Rees*» Cyclopedia, under the article Conductors), ^^'^^^ ^iJf^'

308 I J'R^tEKTlON OF DAMAGE BY LIGHTNING.

to pfbve the best conductors, he found the same charge frotn
an electric machine melted 4 incliesof gold wire, 6 inches of
brass wire, 8 inches of silvered copper, 10 inches of silver,
and 10 inches of iron wire; so that gold is the best con-
ductor, and iron the worst. Brass stands next to gold in
. the quality of a conductor. Cavullo says, that copper and
brass are the best conductors, and also that they never rust ;
but to make them of copper or brass would be a very great
expense, and then, if not drawn through plates, they would
be very uneven on the surface, which is a defect in electric
rods.
Iron tubes J had in prosfject the making of conductors on an im-

plated Willi proved plan, so that they would be equal to solid brass ia
their use, and come as cheap or cheaper than wrought iron,
in a patent T have very recently obtained for combining dif-
ferent sorts of metals, particularly brass or copper, with iron.
By this method we can plate or cover tubes of iron 15 or l6
fdet long, of any diameter, with a coat of brass, from -r^ ^^
an inch, to any thickness ; and so connected with the iron, by
compression, that, when so combined, it appears a solid piece
' ■ of brass, but being hollow, is very light and portable, and

the method used in making them being by drawing them
, through a polished draw phite, all the surfaces are as smooth
and uniform as it is possible to make them. B^ing made
in convenient lengths, they may be sent to any part of the
kingdo«i, and put up in a very shorti time, as one piece screws
into another, so that, when screwed in, both edges of the
brass meet, and join together. Conductors of this kind
would never rust, as what is presented to the atmosphere is
brass only. They would be 4 lighter than iron rods, would
be put up in a very short time, would be quite as cheap as
iron, and furthermore would be the best conductors you can
possibly make. But as I said before that I had given the
subject a good deal of thought, especially the probability
of drawing off the electric matter by conductors, so as to|
prevent its getting to a head and causing by its discharge sa
many accidents ; when I considered the manner of the iron!
rods and their great defects, it set me a thinking how I could
contrive a better conductor than iron, and I flatter myself I
have succeeded. Therefore I leave it to every man to judged

whether

PREVENTION OF DAMAGE BY LIGHTNING. ^QQ

whether what I have asserted is true, namely, the great da- a

naage done yearly by Imhtning, and aiso the great necessity
of providing, if it is possible, some remedy; and if conduc-
tors are the only means that promise a remedy, those con-
ductors which atibrd the most beneficial and lasting results
wiU certainly ue chosen. This is. Sir, very much like rt-
commending my own invention : but if my rods are the best,
which 1 leave to every candid man to judge; and if society
is benttitted, 1 see uo reason why I siiould not be benefitted
al&o. The pres<?nt conductors on chipboard, where any are Conductors for
used, are I believe constructed of chains, which are the^^'P'*
worst of all conductors, as the lightning has to run down
the most irregular of surfaces, besides their being so clumsy.
But my brass rods might be so attached to the mainmast,
and the collecting point raised above the top ; and where the '

joints of the mast are, there might be a round universal
joint, that would bend in every direction with the mast. The
rod might be carried down thus into the sea, and the expense
of them would be so trifling, that one would hardly think
any vessel would be without one, especially when it is con-
sidered, they would be made of a metal allowed by all who
have written on electricity to be the best conductor of
lightning.

I am. Dear Sir,

B. COOK,

Annotation. W. N,

The subject of conductors for lightning being still ob- Conductors foi
8cure, I have with ples^sure inserted Mr. Cook's communi- figl^tning.
cation without considering, as at all needful, that an ac-
quiescence in its contents should be implied throughout on
my part. Being founded on the generally admitted doc-
trine, it is in many respects entitled to coniideration, and,
like all other ingenious researches, is calculated to excite
investigation. On the present occasion I would remark,
that the course, disposition, and striking places of thunder
clouds appear to be governed in a very great measure by

certain

3\0 DESCRIPTION OF MOUNT MEZIN.

Condu.trs for certain condticting parts lying along or within the earth
lightning. either as ridges or internal masses, and that the stroke from
a stratum of clouds, many mileb in length, seems to be de-
termined by an nction which extends far beyond the influ-
ence of iny metallic rod, — even supposing this last to be in-
serted into the conducting mass itself: that the whole pro-
cess of atmospheric evaporation and condensation appear to
be accompanied with electric phenomena upon a very ex"
tended scale, but most strikingly manifest when the changes
are rapid ; this last being the only difference between thun-
der storms and common squalls or showers : and that it does
not seem probable, that our rods can essentially modify the
conr&e of these effects. Other more remote considerations
would offer, if they could ^ such as the possibility of an in-
terruption of the ordinary course and frequency of showers,
' which Darwm thought within the reach of human power,
and the greater probability that the atmospheric electricity
of a whole country would soon destroy a>iy series of conduc-
tors: but the affair of the poor-house at Heckingham *, in
Norfolk, which, about thirty years ago, was struck and set
on fire by lightning without touching any one of eight ele-
vated metallic conductors attached to the building, has been
considered as a proof of the very limited influence of these
Tods, and tha*^^ their power of proftecting a single edifice re^
quires the condition, that all the conductors should be con-
nected together, and with the metallic parts of the house.

XV.

Extract of a Letter from Mr. Cordier, Mine Engineer, on
Mount Mezin f.

Mount Cenls. jl_ HE passage of Mount Cenis has been laid open to view

Alternation of by the new road. We see there vast strata of gypsum, which

gypsuni and alternate with the rocks of micaceous schist, compose nearly
micaceous . . ,

schist, a twentieth of the mass of the mountains, and show thcm-

* See Philos. Trans, of that time.

t Journal des Mines, Vol. XXVI, p. 230.

selves

DESCRCPTION OF SfOWlrt? MEZIN. SI I

selves equally in the lowest anfl in the highest parts of the
mountains. Saussufre hud supposed this gypsum to be su-
perposed, but I easily satisfied myself, that it is in reality
intercalated.

I have revisited almost all the extinct volcanoes in the in- Extinct volca.
ttrioi- of France. ,My object was to verify many of tny de- noe3 in France.
scrip»ions, and to make new ones, wherever 1 could find si-
tuations truly classicTil, that is, capable of being cited as
exhibitiuii a complete and perfectly circumscribed geologi-
cal phenomenon.

1 have paid much attention to Mezin, which is a volcanic Mount Mezin.

system aualoojous to P.uy-de-Dorne and Mont-d'Or,' but

much better characterized. We see there two orders of vol- Two ordeis of

canic substances'; those that were anterior to the last period ^o^^^^"'*^ s"^'

. ■ stances,

of deluge, and those that have been thrown out subsequent

to all the revu^uhous the Earth has undi rgone. The mass The mountain
of the mountains is composed almost wholly of primitive ^-^"^'^'^^*
formations. Cons-idered as a whole, it is a frustum of a
very obtuse cone often leagues radius. I find, with Mr.
Ramond, that it is 1774 met. [1939 yds] above the level of
the sea, and about 800 met. [874 yds] above the granitic
flat on which it rests. It exhibits the ruins of a volcanic co-
lossus, unquestionably much loftier and more extensive.
W« find in it this very remarkable peculiarity, that most of The volcanic

the incoherent matters thrown out have underojone no alte- substances un-

. , ^ changed,

ration, and have not been changed either into tnfs or brec-
cias. The red scoiae in fragments, and the black stonj-
scoriae, appear with all the characters impressed on them
by the fire. Add to this, all the currents, or segments of
currents, are accompanied with scorified crusts above and
below. The interior of these currents presents only lithoid
lavas, from the basaltic porphyry to the compact earthv, or
fine-grained granular porphyry with base of felcspar. The
tkree varieties with base of feldspar are frequently found in
the same current, and thus exhibit the transition of the Transition,
thr^e pretended species, domit, the base of graystone, and
clinkstone.

The modern lavas are not very numerous at Mezin. They The later
are all formed of porphyritic basaltes witii fine crystals of *^'
peridot, and pyroxene, mixed with nodules of granular

peridot.

•3IS sciExNTiric News.

peridot. The same nodules and the sarae crystals are
found in the sconce tliat compose the craters, whence these
lavas issued. The modern currents having; almost all flowed
■ through narrow and deep valleys, the torrents have resumed
their beds, by hollowing out vast furrows in the lava. Hence
result sections admirable for their height, which sometimes
rear hes to 200 French feet ; for the regularity and dimen-
sions of the basaltic columns; or for their extent, as they
frequently reach whole leagues. These superb curtains are
ornamented with scoriae at top and bottom. The decompo-
sition of the lower scoriae gives rise in certain places to a cu-
rious phenomenon. The tuf, or wacke, resulting from it,
XrarsUjon. mixes with the river-mud or s-and, which the lava had cover*!'
£d, and these places exhibit a transition of the sort that
Werner admits: that of sand, or clay, to basa'.tes ! The
modern basaltic colufnns of Mezin are unquestionably the
finest ever yet observed,
Kewkfndof The whole system of Mezin rests on a new kind of gra-
granite. ^^jj^^ jj^^p ^i^ich pinit enters in the proportion of a twentieth,

8 tenth, and even a third. This rock occupies a space of
more than 250 square leagues, and extends to what was for-
merly Foret, where it serves as a matrix to the su bstance that
was taken for emerald, but is only a translucid pinit. Of
this I satisfied myself pa the spot.

SCIENTIFIC NEWS.

Hfiport of the Proceedings of the Mathematical and Physical
Class of the French Institute*

Respirati
fshes.

ion of O)

f Concluded from p» 240.J

INCE Mr. von Humboldt*s return tb France, he has
made many experiments on the respiration of fishes, in con-
cert with Mr. Proven9al. Spallanzani and Sylvestre had
shown, that fishes do not breathe by decomposing water, as
some had supposed, but by water obstructing the oxigen
dissolved in it, or by coming to the surface to collect oxi-

«iIENTIFIC NEWS. ^|^

gen directly from the atmosphere. The experiments of
Messrs. von H. and P. have gone farther. Seven tenches
were placed under a jar filled with river water, containing
4000 cent, cub. [243*6 cub. inch.]. After living in it eight
hours and a half, the analysis of the air still foand in the
water showed, that the fishes had absorbed in this time
145*4 [8*85 cub. in.] of oxigen, and 57*6 .[3'5] of nitrogen,
and that 132 [8] of carbonic acid had been produced.

In water deprived of air the fishes were uneasy, and in Effects of dif-
about twenty minutes fell motionless to the bottom. In otHhei^^**"
pure oxigen they appeared to respire eagerly, and spread
their gills more. In nitrogen and bidrogen they kept their
gills closed, seemed to dread the contact of these gasses,
and died soon after they were put into the water containing
them. Carbonic acid too kilU them in a few minutes.
But it is not by their gills alone that fishes absorb oxigen
and nitrogen, the whole surface of their bodies has the fa^
culty of acting on these gasses. After the fishes were taken
out of the water containing the deleterious gasses, a small
portion of carbonic acid was found in it, exhaled probably
from their bodies.

Mr. Provencal has also made some experiments on the Respiration of
respiration of mammalia after the eighth pair of nerves ^^"'^V^. ,
had been divided. The animals gradually absorbed less nerves was di-
oxigen, and produced less carbonic acid, after the operation. ^^^^'
At first their respiration was not apparently weakened ; but
it soon became feeble; and at length ceased altogether:
probably from the cessation of the mechanical functions of
the thorax. The heat of the animal diminished soon after
the division of the nerves, and proportionably with the re- »
spiration. '' '*''■' '•'•-■-•■'-"- -•-■— '^'"^■■■'. '' "'^ ' ■''^■■:

With the functions of the airbladder of fishes we arc not AirbUdderof
yet well acquainted. In some it has a duct communicating ^**
with the stomach. In others this duct is wanting, and it
contains a peculiar organ of a red colour, and a laminated
structure. In some both this organ ^nd the duct are found,
and in a few this bladder has muscl&s. The air contained
in this bladder is a mixture of oxigen and nitrogen, the
former being in greater quantity in proportion to the depth
^t which the fish Uvea in the water, Its absence does not

appear

314

SCIENTIFIC NE\rd.

ippcar injunous to Respiration, though it do€s to the ppo»
duction of carbonjc a<?id. Tenches tVom which it has been
removed swim, dive, and rise to the sr.rfuoe, with as much
ease as otfeiers. Such are the principal resuUs of the differ-
ent inquiries of Messrs. Duvenoy, Delaroche, von Hum-
boldt, Provencal, and Cuvier,
Foisonof the Drs. Magendie and Delisle have made many experiments
'^^ on animals, chiefly do^s, with the poison* of the upas.

Whether introduced into the system V)y the bloov»vPssels or
lymphatics, by the way of the intestines, or by a wound, the
animals died universally convulsed. It appear:* particularly
to affect the spinal marrow, and to enter the system only by
means of the circulation. It seems to act but very nJi-
rectly on the brain, thus sh'-win^ an independence be-
tween it and the spinal marrow, that is not indicated by
anatomy.
Juic«ofdead- Mr. Vauquelin has found, that the juice of belladonna.
If nighidiade. when swallowed by dnimals, produced in tuem a deliriurai
exactly similar to that of opium. Some ex'j.erimer.t8 of
Mr. Sage confirm the action of this juice on the nervous
system.
CUisses inject- Dr^ Nysten has examined the effect of different gassca
•d into rtie iniected into the bloodvessels. Atmosphei'ic air, oxigen, ui-^
trcjij oxide, carbonic acid* carbonic oxidCj sulphuretted
hidj'ogen, &e., v^ere uot deleterious. Oximuviatic, ammo-
niical and nitrous acid passes appeared to act by irritating
very violently the right auricle and pulmonary ventricle.
Sulphuretted hidrogen, nitric oxide, and niVio^^en were in-
jurious to the contractibility of these parts. Some others
so changed the nature of the blood, that respiration vas
unable to convert itfrora venous to arterial.
Stingtof ijv In a paper on the means of remed iuij the sting of the

sects and weever, trachinus dtaco L. ; and on the effects of the poison

©f the tarantula, with the mode of cure used in Spain ;
Mr. Sage recommends the internal and external use of the
volatile alkali.
Rotations of lo a report onthe Means of improving: Agriculture by
c»*:»P». , Rotations of green crops by Mr. Yvart, the committee re-
commends it as answering the important purpose of showing
how land may be rendered constantly productive without
exhausting it. Mr,

I

SCIENTIFIC HEWS. 315

Wr. cU Cubiere reada paper on the cultivation of t"he Culture <>f th«
bald cypress (le cypreS'ckauve), showing the advantages of cypress,
this hue tree.

Mr. Leblanc, who has r<?sided several years in America, Vicugn*.
communicated his ideas of i!»e ease with which the vicugna
might be domesticated in the Alps and Pyrenees.

Mr. Poyfere-de«Cere read an account of the mode of Wool,
washinj^ superfine wool in Spain.

Mr. Percy related some curious observations on the fa- Alcarazis.
bvicatious of the jars and alcarazas, which the Spaniards
employ for preserving liquors, and tor cooling them.

In the report of the Class of History and ancient Litera- Ancient bell
ture, a paper by Mr. Gregoire is mentioned, containing a of verylou<i
description of a singular ancient bell, from the convent of
Bobbis, in Piedmont. This bell is about 9 dec. [35'4
inches] in diameter, and of a spherical shape: one hemi-
sphere being complete; the other formed of ten branches,
broad at the base where they join the upper half, and ta-
pering to a point*. Its sound is much louder than that of
a bell of the common form of the same weight. A small
portion, taken from the ear, was analysed by Mr. Vauquelin,
and found to consist of 76 parts copper, 20 tin, and 4 lead.
I^lr, Vauquelin was satisfied, that these were the only metals
present; though, from the smallness of the quantity ana-
lysed, the proportions may not be strictly accurate. He
^: supposes, that the lead was an adulteration of the tin, though
advantageous to the sound. Messrs. Molard and Montgol-
fier have cast four other bells of the same forrri and size,
before they had a knowledge of Mr. Vanqnelin's analysis^
using ditierent compositions. That which came nearest
in sound to the original was a mixture of equal parts of.
copper, brass, and tin.

Royal Society of Sciences at Harlem*

The prize for the question concerning the insects most Insects in-
injurious to fruit trees, their natural history, and the means -'""'^"'^ '<^^r^*

* Nothing is said of the thickness! of the metal, or of the space left
l)Oiweon the points of the branches, which appear fr«m the description
not to be unit td, C.

pf

316

Prize ques-
tions.

Graduation
houses for
making salt.

Effects of ma-
nuxus.

Ancient topo-
graphy of
HoUand.

SCIENTIFIC NEWS,

of dcstroyinnj them, was awarded to Mr. Fred. W, Freyer,
councellorof the court and of the regency of Saxe Hilburg-
hausen. '

The following questions, hftving received no eatisfkctory
answer, are repeatied,

1. May graduation houses, for making ^alt from seawater
be estabhshed with advantage on the coast of Holland j n d
how may they be best conducted, considering the circum-
stance of the country?

2. From the process latfely made in the physiology of plants
hov Far do we know in what way vegetation is promoted by
different manures in various soils; and what indications
uiay we deduce from the knowledge we have acquired, with
respect to the fertilization of uncultivated and barren land?

3. How far can the study of ancient authors, the examina-
tion of antiquities, and observations made on the spot, serve
to determine with certainty what the face of this country
was formerly, particularly under the dominion of the Ro-
mans, including the course of the rivers, and extent of
the hikes, and what changes they have successively under-

Chanwe* ot> '^' What do historical accounts of acknowledged authen-

ihe coasts of thenticity teach us of the changes, that have taken place

" ' * on the coasts of Holland, the islands, and the arms of the

sea that separate them ? and what useful information may

be derived from it.
Ancient and 5. Do the tides on our coasts rise higher than in former
present height atges, and fall proportionably less low? — If so, how far

can we determine the quantity of this difference in ages

more or less remote, and what are the causes of the changes ?

Do tiiey arise from gradual alterations in the outlets of the

waters, or do they depend on external and more remote

causes ?
Renovation of 6. As the experiments and observations of philosophers

♦heoxigeii of jjave shoAvn of late, that the quantity of oxigen eas emitted
the atmos- . _ . , i

phere. by plants is by no means sufficient to supply to the atmos-

phere what is consumed by the respiration of animals, com-
bustion, absorption, &c., by what other means is the due
proportion between the component parts of the atmosphere

pontiouallv preserved ?

7tHow

SCIENTIFIC NEWS. 3J7

7. How far has chemistry made known the component Immediate and
parts and principles, both proximate and remote, of plants, renioie priuci-
particularly of those employed as food ? and how far c&n

we deduce from what is known, or what may be dig-
covered by experiments, combined with the physiology of
the human frame, what vegetables are best adapted to our
use in a state of health, and in certain diseases.

8. What is the cause of the phosphorescence of the water Phosphores-
in the seas and inlets in and around this kingdom? Does 5^!^" ** * *
the phenomenon depend on the presence of living animal-
cules? If so, what are they, and are they capable qf im-

partinsf to the atmosphere any injurious properties? — They
who purpose to answer this question are requested to con-
sult the roost recent and accurate writers on this subj^ect,
particularly Viviani, Genoa, 1805, and to examine how
far this phosphorescence, which is very remarkable on some
parts of our coasts, is connected with the prevailing diseases
in unhealthy sseasons.

The following new questions are also proposed.

9. As the secretion of milk in cows appears to be in- Milk of stall
creased, when they are fed in stables on potatoes, carrots, ^^^ covfs.
or beetroots, it is required to show by experiments and ob-
servations, whether the raiik of cows be really increased by >
these articles of food, an<l under what circumstances; in

what way they can be given with most advantage; whe-
ther the quality of the milk be altered by this feeding; and,
if so, what this alteration is, particularly with regard to the
quality and quantity of cream and butter produced.

10. As the antiseptic quality of common salt appears Antiseptic
not to depend solely on the muriate of soda, but also on quality of the
the muriate of magnesia, which adheres to common salt, it J^da and mag-
is required to determine by experiments the comparative nesia.
proportions of the antiseptic quality of these two salts; in

V'hat proportions they should be mixed, to prevent putre-
faction as long as possible, without the taste of the sub-
stances we would preserve becoming less agreeable; and
whether it would be advantageous to use muriate of niag-
ncsia alone, particularly in voyages to hot climates.

11. What

518

SbeU lime.
Kitre beds,

Nature of lu-
minous me-
teors.

Meta!s from
thtt alkalis.

An omma ab

Chemical ex*
planatioas of

«l(ic{.ficity.

SCIEKTinc NEWS.

11. What is the chemical reason why stone lime makes
OQ the whole more firm and durable buildings than shell
lime, and how may the latter be improved in this respect?

X'i. May nitre beds be profitably formed in this country,
particularly in places where the water is impregnated with
fceveral substances produced by the putrefaction of animal
matters? and what rules should be observed respecting ,j,
them? I

13. What do we know, from incontestible observations, 1
of the nature of luminous meteors, or those that have the |
appearance of fire, lightning excepted, which occasionally
appear in our atmosphere? how far can they be explained
by known experiments? and how much is there still gra-
tuitous or doubtful in what the philosophers of the present
day h«ve asserted respecting them ?

14. C'in it be demonstrated by incontrovertible experi-
ments, that ti^e substances which have the appearance of
metals, produced from alkaline salts, are real metals ? or
are there sufficient reasons to maintain, that they are hy-
dr.irets, p oduced by the combination of hidrogen with the
alkalis? What is the most certain and convenient mode of
producing these substances from the alkaline salts in pretty
considerable quantity by means of a high tenipfrature ?

14. Mow fiir may We still maintain the doctrine of Harvey,
that animals are born in general from preexisting eggs, and
that plants spring only from seeds ? and on the contrary
what are the principal observations that show, that there
are animals and plants, which are produced in a different
mode ?

l6. What judgment is to be formed of the chemical
explanations attempted to be given of electrical phenomena ?
Are there any founded on sufficient experiments, or that
may be proved by new ones ? Or are tliey to be considered
bitherto as hypotheses by no means proved, or advanced
without valid reasons?

The time for answering all these questions is previous to
the 1st of January, 1812. Beside the usual medal, value
Voduc, [£13 : 17 : 6], 30 ducats in addition will be given
' to those who answer questions 2, 3, 4, 7* 10, 11, 13, 14,
and 15 ; and 50 due. [£23 : 2 : 6] in addition to questions
I uod 5. Academical

SCIENTIFIC NEWS. 519

Academical Society of Sciences, at Paris,

At the meetinorin September, 7 809, Mr.Nauche commu- Contraction of
nicated some experiments he had "made on the contraction ^^ "^"^^*^
of the muscles in froj^s. The object of these was to shovv,
in opposition to the assertions of prof. Richerand and Bi-
chat, that the contraction of the muscles may take place
independently of nervous influence, or the influx of the jndependeal
blood. We learn from comparative anatomy, that this . is p^ "^'■^"**s
the fact in thousands of anirauly, which have neither blood- the bioo4,
vessels nor a nervous system, yet this faculty is excited in
them with great intensity. It may even be aflirmed, that
it is more active, stable, and independent of life, in propor-
tion as the animal is less perfect, and lower in the zoological
8cale« These facts appear to confirm the opinions advanced
by Mr. Dubuisson in his Essay on the Properties of the
Vital Power in Vegetables, that contractibility, or irritabi-
bility, is inherent in the muscular fibre, and peculiar to it;
as sensibility is to the medullary substance, renitence and
elasticity to the albugineous fibre, and tone to the cellular
texture.

Societi/ of JEncovragemenl at Paris.

A report on the thread stockings manufactured by Mr. Thread steck-
Detrey, sen. says, that they combine fineness, strength, and ^^8^'
beauty. The evenness of the thread, its lustre, and accu-
rate spinning are remarkable. They are three thread.
They are not dear, as the price is 15 fr. [125. 6d.] a pair;
and when it is considered, that cotton stockings are manu-
factured in France as high as 48 fr. [£-2.], not exceeding
them in beauty, and inferior in strength, they must be es*
teemed a public benefit.

The gold and silver medals, on count Rumford's dona- Couut Rwm-
lion, have been adjudged by the president and council of fof^**ni«<ials.
the Royal Society to Mr. Malus, for his discoveries of cer- *
tain new properties of reflected light, published in the 2d
vol, of Meraoires si'Arcu^il, which we shall insert the earli-«
est opportunity.

<520 SCIENTIFIC NEWSI*

Jacksoniaii The Royal College of Surgeons in London have awarded

preiaiiuB, the Jacksonian premium of j^lO, and an extraordinary pre-
mium of £lO, to Mr. John Smith Soden, of Coventry, and
to Mr. James Gillman, of Highgate, both members of that
college, for their dissertations on the Bite of a Rabid Animat,
from the consideration, that such two dissertations are highly
meretorious productions, and are equally worthy of the
Jacksonian prize.

I

new con-
It c action.

Cotton manu- The cultivation of cotton, and its manufacture, are said
f^toiy la ^Q Y)e carrying on to a considerable extent in Italy.

Vessel of a Mr. Daubusson de la Feuillade has exhibited on a canal

near Paris a model of a vessel of his invention. The model
was 25 feet long, 52 inches broad, and did not draw 5 inches,
of water. The inventor proposes to builcl one 200 feet long,
and 50 feet beam*, which ia to carry 66 guns. It is to
have four masts, be deep waisted, and with two thousand
men, and provision for 50 days, would draw only 91 f*?et of
water. It will sail faster, and lie nearer the wind, than
any other vessel. Its sails are to turn quite round, and
cither end may be made the stem or stern at pleasure, so as to
render tacking unnecessuiryf. In a dead caim a rame aspi^
rante is to supply the want of wind, Cork sheathing, and
airvessels of copper, afe to be employed, to render it inca-
pable of being sunk. Its intention is to surprise an enemy''*
harbour.

Valuable writ- An inkmaker at Paris professes to have discovered a
inj Ink, vegetable flukl ink, which never thickens or loses in any

degree its fluidity by evaporation, is always free from sedi-
ment, and never occasions iron moulds, or in any way in-
jures linen or clothes, that may be accidentally soiled with
it. He adds, that what is written with it never becomcB^
yellow by age. Sonnini says, that he has long used this
new ink made by his neighbour, Mr. Alphonsus Wee, and
that it possesses the', qualities ascribed to it.

♦ This is not proportional to the model. C.

•f^ The inventor appears from this to hare but little knowledge oCruiU
gating a ship. C.

'?'.^

JOURNAL

OF

NATURAL PHILOSOPHY. CHEMISTRY,

A^iTd

THE ARTS.

SUPPLEMENT TO VOL, XXIX,

ARTICLE L

Method of assisting the Escape of Pef^sons^ and the Re*
moval of Property from Houses on Fire: hy Mr, Joun
Davis, iVo. 7, John Street^ Spit aljie Ids*,

SIR,

1 BEG you will hate the goodness to lay before the So- Machinefbrsav-

cictyof Arts, &c. a machine, which I have invented, for "^g P^^^^"^ ^J^*^

•' ' ' ' property frgm

more effectually saving persons and property from fire. fire.

It appearing to me a desirable object, that the public
should be in possession of an apparatus better adapted for
the above purpose than any now in use, I have endeavoured
to strike out an entire new plan of a machine calculated for
the use of a parish, which can be easily removed and ad-
justed to any window, with a convenient apparatus or box,
movable up or down, so as to receive persons or property.
I have completed such a machine, which has answered my •

expectations, and been approved by several gentlemen who
have seen it in action.

* Trans, of the Soc. of Arts, vol. xxviii, p. 175. Fifty guineas
were voted to Mr. Davis for this invention.
Vol. XXIX. — SuprLEMENX. Y The

I

323 ^^^^ rscApE.

The machine is at Mr. Jarties Bevan's mahogany-yard.
City road, where it shall be exhibited to a committee ap-
pointed by the society whenever they please,

I am, Sir,

Your obedient humble servant,

JOHN DAVIS.

No 7, John Street, Spitalfielis^
Jan. 10, 1809.

Reference to the Engraving of Mr. John Davis''s Fire-
Escape, PL IX.

Description of The plan of my fire-escape is calculated for the use of a
tiie machine, parish ; its.principle consists in three ladders, ABC, applied
to each other by four clasp irons on the top of each of the
two lowermost, which are so contrived that each ladder
may slide into the one beneath it; on the top of the lower-
most ladder A two pullies are fixed on the inside, over
which two ropes a a pass, and situate between the lower
kdder A, and the middle one B. The ropes are made fast
to the bottom of the middle one on each side in a proper
direction with the pullies on the top. The upper la^ldcr C
is attached to the middle one in the .same manner, and on
the top it carries two horn pieces, D, made of iron, and
turned off at each end similar to two horns, which are four
feet wide; their ends are sharp to pitch on each side of a
Avindow, and with its points hold the ladders steady. The
three ladders when shut down are about fifteen feet in
height. They are placed perpendicularly in the middle of a
^framed carriage, EF, of nine feet six inches long, and five
feet six inches wide, mounted upon four wheels F. On
each side of the carriage a windlass is placed ; that marked
G on the right side of the carriage is for the four ropes « a
and b b, fixed two to each ladder AB. By turning this
\v indlass the ladders may be wound out from their standing
height of fifteen feet to forty. Over this windlass is a screw
turned hy the winch </, by turning which the ladders may
be inclined against the house with all imaginable ease. On
the top of the upper ladder C on the outside, are two pullies,
oyer which two chains are conducted to the windlass H on

the

FIRE ESCAPE. ' 3^

the left side for the purpose of carrying up a box I ; two of
"which travel with the fire-escape, so that in the event of
one being filled with small valuables, it may be unhooked^
and the other K put on, which will save time. The whole
apparatus may be drawn by one horse, or six men, and when
arrived at the scene of danger may be adjusted in two
minutes. If every parish would provide one of these
escapes, and keep it where it might be brought out on the
first alarm, I feel persuaded it would lessen the m^ny accj.
dents, which occur by fire in the metropolis.

I have the honour to be, Sir,

Your obedient humble servant,

JOHN DAVJS,

No. 7, John Street, Spitalfields^
May 14, 1«10.

: Farther Observations fro^m Mr. Dai>is on his Fire^Bscape,

SIR,

I BEG leave to return you, and the gentlemen of the
committee, my sincere thanks, for the kind attention I have
experienced; and should you think the following hints
likely to give any additional information on the subject of
jny fire-escape, you will have the goodness to submit them
to the consideration of the committee.

Certain it is, that, however good any principle may be, Hints with re-

ihe practice must also be so to be effectual ; therefore it isf^""^ to escape

^ J from fires.

my opinion, that every parish should be provided with a

machine on my principle, to be kept in some convenient
place, easy of access. The key should be kept at the watch-
house by night, and by day at the nearest public-house ; if
this, which ought to be, were the uniform custom, it would
soon become familiar, and be attended with no expense.
On the alarm of fire, I would have the machine brought
out directly, as I consider it an improvident method, when
• a house has been on fire some time, and some unfortunate
sufferer should appear in need of prompt assistance, to have
to search about for the keys of a churchyard, or some other
obscure place to bring the fire-ladders ; which, when brought,

y^ , if

324f FILTRATION OF WATER.'

If not exactly the right height, are useless ; and when thii,
which is not unfrequent, is the case, the remedy is al-
most as bad as the disease, witness Mrs. Smith, having
fallen off a parish ladd^f, at Chelmsford, while endca-
Touring to save herself in that dreadful fire, in March,
1808. It would be needless for me to enumerate in-
stances, where a well-timed outward apparatus would have
been of essential service — the thing is self-evident, and the
occasions for their use have also been many. I would also
propose, that a board should be put up, offering a reward
sufficient to stimulate persons to bring the machine — for ex-
ample, ten pounds for every life saved by it. I think no
person would think it too much, who had been saved. This
would hare the good efl'ect of having it always in time,
which is most essential, as twenty shillings are not sufficient
to induce men to the necessary trouble attending such
labour.

Having thus offered my sentiments, respecting the good
effects which may be derived were certain regulations put
in force,

I remain, with great feeling for suffering humanity,

Sir,
Your most obedient and humble servant,
JOHN DAVIS.

II.

New Method of applying the Filtering Stone for purifying
Water: by Mr. William Moult, No, 37, Bedford
Sqaare *.

SIR,

Inconveniences iF you think the following information, relative to a new

in the common method of filtering water, is deserving of the attention of the
mode of using _. _. „ t«i_ tii.i^ i

filtering stones. Society of Arts &c., 1 Wish you would lay it before them,

♦Trans, of the See of Arts, vol. xxviii, p. 212. The silver
medal was voted to Mr. Moult.

My

4

FILTRATION OF WATER. 325

My objections to the old method of filtering by putting
water into the filtering stone are, that the dirt falls to the
bottom, and fills up, or chokes the pores of the filtering*
stone, so that the stone requires frequently to be cleaned
with a brush and sponge to allow the water to pass, after
which the water passes through the stone in a muddy state
for two or three days ; it likewise requires to be frequently
filled, and as it empties less water comes into contact with
the stone, and therefore a smaller quantity, in such a state,
can only pass through. Likewise a filtering stone used in
the common way soon becomes useless, from the filth in-
sinuating itself into the internal parts of the stone, out of
the reach of the brush.

In the method I propose and practise, the filtering-stone Improved m©»
is placed within the water to be purified, which presses upon^ ° '
the outside of the filter, and the stone does not require to
be supported in a frame as it needs on\y to stand within the
water cistern ; it will thus filter, in an equal time, double
j ^- the quantity of water procured in the common mode; it *"

fills itself, and requires no cleaning. I have upon this plan
used one for more than three years with great success,

I am, Sir,

Your humble servant,

WILLIAM MOULT,

No, 37, Bedford Square J
April IS, 1810,

Certificates.

We, the undersigned, having inspected and examined a Testimonies of
new mode of employing the ordinary filtering-stone, dis-.^^^**^^"^^^^
covered by William Moult, are of opinion that its supe-
riority over the customary method is so great as to entitle
it to particular notice.

That it not only supplies an infinitely greater quantity of
purified and limpid water, but is capable of preserving its *

porosity free and pervious for years together, by an occa«
sional self-operation.

That by this valuable process the principal objections io
drip^stones is removed, viz. the constant labour they require

to

3gg REtlEF OF UOtlSES FALLEN IN LOADED CARTS.

to keep them clean hy means of brushes, w ithout eventuaTIy
producing the intended effect, and without prcTcnting their
being finally rendered useless.

D*Arcy Preston, captain in the Royal Navy ;

Charles Gower, M. D. ;

Thomas Pitt, Esq. V. P. Wimpole street;

Richard Davenport, Esq. Wimpole street.

Reference to the Drarcing of Mr. Moidfs Filiering
Apparatus^ Fig. 1, PL X.

A A is the cistern containing the water to be filtered ; the
iiltcring stone B is suspended in the cistern by a ring around
the inside of it, which catches the projecting part of the
stone; the water in the cistern filters through into the
stone. D is a siphon, which conveys the filtered water
from the inside of the stone into a cistern E, which is
the reservoir for clean water, a a cock to draw it off as
it is wanted. By this mode of filtration the impurities of
the water are deposited in the bottom of the cistern A, in.,
stead of beitig left in the bottom of the stone as in the
usual mode.

III.

Method of raising a loaded Cart, when the Horse in the
Shafts has fallen: by Mr. Benjamin Smith, No, 11,
Turnham place^ Curtain road^ Shoreditch *.

SIR,

i. HAVE taken the liberty of sending you a model, with a
brief explanation of the utility of my invention, in order
that it may be laid before the Society instituted for the En-
couragement of Arts &c., to whose comprehensive judg-
ment and abilities I with great deference submit it for their
determination, whether they think it likely to be attended

* Trans, of Soc. of Arts, vol, xxviii, p. 215, Fifteen guineas
were voted to Mr, Smith,

vfUh

nrUEF OF HORSES PALtEH IM tOADED CARTS; 327

\?ith the success and utility which I flatter myself it de.
serves. From the simplicity of the construction and the
trivial expense attending it, I presume there will be no bar
to its universal adoption. I respectfully submit it to the
discernment and decision of the society, who will, I am
convinced, give it all the merit and approbation it may
deserve.

The reason which prompted me to undertake this bu si- Horses falling
ness is from having seen a horse, which had fallen down {"^^^^^J^J^**
under the immense weight of a heavy loaded cart, where it
lay for a considerable time in that painful and dangerous
situation, which naturally excited compassion even in the
most obdurate heart. Every person frequenting the streets
of this metropolis must have witnessed similar scenes; and
indeed it surprises me, that long before now some expe-
dients have not been publicly suggested to remove the mis-
chief arising from such occurrences, considering the great
encouragement that is given in this enlightened age to all
useful improvements.

Having conversed on this subject with persons who possess Much injured,
considerable knowledge of horses, and who constantly em»
ploy these noble animals, I find, that horses remaining so long
as they usually do in such improper positions, and from
being often dragged a considerable distance by fruitless en-
deavours to raise them, are much endangered in their health
and lives, and that their situation upon the stones is more
prejudicial than the injury received by the fall.

I flatter myself, that my method will be found to raise the Method of re-
whole weight of the cart, and a considerable part of that of ^^^""'"S t^^eia.
the horse, in the short space of three or four minutes from
the moment of the accident, by means simple aud useful^
and within the reach of the meanest capacity to execute;
and that the whole apparatus will not cost above fifty
slvllings, and will last many years. Requesting your kind
atttution,

I am, Sir,

Your most obedient servant,

BENJAMIN SMITH.
Nelly Turnham place^ Curtain roady

SioredUch, London, Dec» 13, 1809,

Advantages

3g8 nXLlV.T OF HORSES FALLEN IK LOADED CARTS.

Advantages derivable from this Invention:
Ad\Tintages, 1. — The invention is of itself so simple, and the opera-

tion so conspicuous at the first view, that the whole process
may be easily comprehended and executed.

2. — The apparatus may be fitted with little difficulty to
any cart now in use for heavy loads, such as bricks, eoals^
corn, or the like.

3. — The chains, which lead from the uprights at the back
part of the cart to the fore part of it on each side, are for
the purpose of taking the purchase therefrom, and making
the back part of the cart act as a lever at the time the horses
are drawing behind, which without fail, with the strength
of one, two, or three horses fastened there to raise the one
which is down in the shafts, will instantly assist him to get
upon his feet.

4' — The number of horses to draw a cart are usually in
proportion to the weight contained therein; therefore.su p#
posing three horses are employed to draw it, and the shaft
horse falls, the carman has only to luihook the two leaders,
and then hook them to the short chain at each side of the
back of the cart, and with their strength the fallen horse
will be so relieved from the weight, as to r^ise hioqself
without farther assistance.

5.= — The same principle may be applied in diiferent ways
from what I have shown in the model; for instance, another
mode may be adopted by framing the tail-board of the cart
gtrong enough to bear the purchase; and, with the use of
the two side chains above mentioned, it may be made to an-
swer the purpose.

Another plan, though more expensive, is by obtaining two
wrought iron uprights to be fixed as substitutes for the
truss staffs at the back part of the cart, with a hole in th«
top of each to receive an iron rod, which is occasionally /o
be introduced, reaching from one side of the cart to ihe
pther, c6nnecting the two uprights together; when in ao,
^pn the two side chains to be used a^ in other cases.

Jle/erinc^

RELIEF OF IIORStS FALLEN IN LOADED CARTS. 329

Reference to the Drazzin^ of Mr. Smith'' s Method of rats'*
ing up a Horse when fallen duzc7i in the Shafts of a loaded
Cart, Fig. 2, PL X.

A is the wheel, and B ihc shafts of a cart, such as is used Explanation of
in London ; C the side rails; at the end of the body an iroa^^^'^^^*
stancheon or truss staff, a, is fixed by the hinge at the lower
end, and at the upper end it is supported by a chain 6, ex-
tended from the fore part of the body of the cart; this
diagonal -chain forms a firm support to the stancheon.
This is all the addition made to the common cart, and is
used in the event of the shaft horse falling, by hooking the
traces of the other horses to a chain d, also fixed to the
Stancheon; the power of these horses, applied at this height
above the fulcruni, will have a great purchase to elevate the
shafts, and set the fallen horse at liberty, as is evident from
an inspection of the figure. The stancheon moves on a
joint on its lower end, ^nd the oblique chain unhooks at d;
the end can be connected with a short piece of chain e fas-
tened to the last of the side rails; the stancheon now takes
the position of the dotted line«/, and the short chain, which
hangs down perpendicular from the end of it, may be taken
hold of by any number of men, to weigh upon and raise the
cart in cases where the horses cannot conveniently be ap,.
plied; the men will in this manner have much greater efibct
than merely (as is the common practice) weighing on the
hind part of the cart.

When the chain is completely detached, and the stan-
cheon sufiTered to hang down perpendicularly, it forms a
prop to support the cart steady while it is unloaded. It
should be observed, that, though only one stancheon ap-
pears in the figure, there are in fact two, one being placed
on each side of the cart.

Certificate.-— Mr. William Whitehead, jun., of Cadogan Testimonial,
place, Sloane street, certified, that he had attended expe-
riments made to ascertain the efficacy of Mr. Smith's in-
vention; that a cart weighing twenty three hundred-weight,
loaded wjth one tun of stones, was raised by means of Mr,*
Smith's apparatus with ease by one horse.

■yhat he very much approves of Mr. Smith's invention,

and

§30 VENTILATION OF MINES OR HOSPITALS.

and thinks it likely to be of great service in general prac-
tice, more especially on account of the business being ef-
fected with little expense. That many carts are already so
formed, that very little additional apparatus will be re-
. quired to complete them for the purpose.

IV.

Method of Ventilating MineSy , or Hospitals ^ by extracting
the foul Air from them: by Mr. John Taylor, of
Holzcell, near Tavistoc/c *\

SIR,

J. SEND you herewith a drawing and description of a ma-
chine of my invention for the ventilation of mines, with a
Ticw to their being laid before the Society for the Encou-
ragement of Arts &c., and hope they will meet with their
approbation,

I am, Sir,

Your obedient servant,

JOHN TAYLOR.

JlolwelL April 9, 1810.

On the Ventilation of Mines, with a Description of a nezo
Machine for that Purpose, See PL X, Fig. 3.

Importance of Next in. importance to the means employed for draining
iremilating underground works from water may be reckoned those,
which are intended to afford a supply of pure air, sufficient
to enable the workmen to continue their operations with
ease and safety to themselves, and to keep up, undiminished,
the artifical light upon which they depend. It is well known,
indeed, to all who are practically engaged in concerns of
this kind, that men are frequently obliged to persevere in
their labour, where a candle will scarcely burn, and where
not only their own health materially suffers in the end, but

^mes,

* Trans. Soc. of Arts, vol, xxviii, p. 219. Tlie silvei: medal
was voted to Mr. Taylor.

theljT

VENTILATION OP MINES OR HOSPITALS. 33\

Itieir employers are put to considerable additional expense
by the unavoidable hinderaucc and the waste of candles and
other materials.

I mean to confine the following remarks to such mines as
are worked upon metalliferous veins, according to the prac-
tice of this district, and that of the great seat of mining in
the neighbouring county of Cornwall, from which indeed
ours is borrowed. We find then, that a single shaft, not
communicating by levels to another, can hardly be sunk to
any considerable depth, nor can a level (or, as the foreign
miners call it, a gallery) be driven horizontally to any great
distance without some contrivance being had recourse to
for procuring currents of air to make up the deficiency of
oxigen, which is so rapidly consumed by respiration and
combustion in situations like these, where otherwise the
Tvhole remains in nearly a stagnant condition.

We are here unacquainted with the rapid production of
those gasses, which occasionally in the collieries are the cause
of such dreadful effects; such as hidrogen gas, or t\ie fire-
damp, carbonic acid, or the choke-damp; the inconvenience
we experience takes place gradually as we recede from
the openings to the atmosphere, and seems to arise solely
from the causes I have before assigned, though it is found
to come on more rapidly in certain situations than in others.

The most obvious remedy, and that which is most fre- Usual resource,
quently resorted to, is the opening a communication either
to some other part of the mine, or to the surface itself, and
as soon as this is done the ventilation is found to be com-
plete, by the currents which immediately take place, often
with considerable force, from the different degrees of tem-
J)erature in the subterranean and upper atmospheres; and
these currents may be observed to change their directions as
the temperatures alternate.

The great objection to this mode of curing the evil is the Objectionable

enormous expense, with which it is most commonly attended. ^"^'""^ ^^^ ^^'
* ' -^ pense.

In driving a long level, or tunnel, for instance, it may happen
to be at a great depth under the surface, and the intervening
jrock of great hardness; in sucli a case every shaft which
must be sunk upon it for air alone, \vhere not required (as
pftea they might not) to draw up the waste, would cost

scye|-al

S32 VENTILATIOV OF MINES OR HOSPITALS^

several hundred pounds; or in sinking a shaft it maybe

necessary, at an expense not much less, to drive a IctcI to

it from some other for this purpose alone.

Attempts to To avoid this, recourse has been had to dividing the

avoid this by a ^>iaft-or level into two distinct parts, communicating near
doubleshaft: „ . . v , , .. , , . ,

the part intended to be ventilated, so that a current may be

produced in opposite directions on each side the partition ;

and this, where room is to be spared for it, is often eflectual

to a certain extent. It is found however to have its limits

at;novery great distance, and the current at best is but a

feeble one, from the nearly equal states of heat in the air on

or by forcing each side. l^»e only scheme beside these, that I know of,

tlown iiir. j^^^ hitherto been to force down a volume of purer air,

through a system of pipes placed for the purpoie, and a

•variety of contrivances have been devised for effecting this ;

most of them arc so old that they may be found described

Common me- in Agricola's work De Re metallica. The most common

thod of doing areby bellows worked -by hand;, by boxes or cylinders of

various forms placed on the surface with a large opening

against the wind, and a smaller one coram uniciiting with tho

air-pipes by a c^-lindcr and piston working in it, which,

when driven by a sufficient force, has great power; but the

Cheaper and cheapest and most efjcctuai scheme for this purpose, where

moreefficaeious . ^^^^gjjj^j,^3 will admit o{ its being applied, is one which I

unethod. . , . /. t rn . 1 1

adopted some time since in the tunnel of the 1 avistock canal.

^ It is by applying the full of a stream of water for this pur-

pose, 'and it has been long known that a blast of consider-
able strength may be obtained in this manner, which has
the advantage of being constant and self-acting. The stream
bring turned down a perpendicular column of pipes, and
clashing in at a vessel so contrived as to let off the water
one way, with an opening at another part for the air, M'hich
being presse 1 into it by t\\c falling water, may be conveyed
in any direction, and will pass through air,pipes with a
strong cwrrent, which will be found eflicacious in ventilating
mines in many instances, as it has likewise, in some cases,
been sufficient for urging the intensity of fires for the pur-
poses of the forge. It is easily procured where a sufficient
fall is to be had, and the perpendicular column can be so
^xed, as that the ^yatcr.from. the bottom may pass off,

while

VtNTILATION OF MINES OR HOSPITALS. S33

^hile the air is forced into a pipe branching from the air-
▼esseK and which is to be continued to the part of the
mine >vhere the supply of fri^h air is required.

I have found, however, that the forcing into vitiated air This an im-
a mixture of that which is purer, even when the bestP*"^^*^^' '^^"^*^^^'
means are used, though a measure which aflfords relief, is
not in bad cases a complete remedy; and where the opera-
tion depends on manual labour, or any means that are not
unremitted in their action, it becomes quite ineffectual.
The foul air, charged with the smoke of gunpowder used
in blasting, and which it strongly retains, is certainly me-
liorated by the mixture of pure air, but is not removed.
While the biasi continues, some of it is driven into the
other parts of the mine; but when the influx of pure air
ceases it returns again, or if during the influx of pure air a
fresh volume of smoke be produced by explosions which
are constantly taking place, it is not until some time after-
ward that it becomes sutliciently attenuated for the work*-
men to resume their stations with comfort.

A consideration of these circumstances led me to think, Pumping out
that the usual operation of all ventilating engines ought to be ^^ V\^']^, ^^
reversed, to afford all the advantages that could be desired;
that instead of using the machines, which serve as con-
densers, exhausters should be adopted ; and thus, instead of
forcing pure air into that in a vitiated state, a complete
remedy could only be had by pumping out all that was ira- ,

pure as fast as it became so.

Many modes of doing this suggested themselves to me. Modes sug-
by the alteration of the machines commonly applied, and ^*^^^*^*
by producing an ascending stream of air through pipes by a
furnace constructed for the purpose. The latter mode
would however have beeq here expensive in fuel, as well as
in attendance; and the others required power to overcome
the friction of pistons, aiid so on, or considerable accuracy
in construction.

I at last erected the machine, of which the annexed is a Machine for
•drawing, which, whiie it is so simple in construction, ^"^^j^^/S^**
requires so small an expense of power, is so complete in its
operation, and its parts are so little liable to be injured by
ir^xir^ ihat^ as far as I can imagine, nothiag mpre caa be

desired,

334 VENTILATION OF Mlx\£S OH HOSPITALS.

desired, where such a one is applied. This engine bears
considerable resemblance to Mr. Pepys's gazometer, though
this did not occur to me until after it was put to work It
will readily be understood by an inspection of the drawing,
Pi, X, fig. 3, where the shaft of the mine is represented at
A ; and it may here be observed, that the machine may be
as well placed at the bottom of the shaft as at tiie top, and
that in either case it i« proper to fix it upon a floor, which
may prevent the return of the foul air into the mine, after
being discharged from the exhauster ; this floor may be fur-
nished with a trap-door to be opened occasionally for the
passage of buckets through it.

B the air pipe from the mine passing through the bottom
of the fixed vessel or cylinder C, which is formed of timber
^nd bound with iron hoops; this is filled with water nearly
to the top of the pipe B, on which is fixed a valve opening
upwards at D. ,

E, the air, or exhausting-cylinder, fnade of cast-iron,
open at the bottom and suspended over the air-pipe, im-
mersed some way in the water. It is furnished with a
wooden top, in which is an opening fitted M'ith a valve
likewise opening upwards at F.

The exhausting-cylinder has its motion up and down
given to it by the bob G, connected to any engine by the
horizontal rod II, and the weight of the cylinder is ba-
lanced, if ne<;essary, by the counterpoise I.
It's mode of '^^® action is obvious. — When the exhausting cylinder is

actien. raised, a vacuum would be produced, or rather the water

would likewise be raised in it, were it not for the stream of
air from the mine rushing through the pipe and v^lve D.
As soon as the cylinder begins to descend, this valve closes
and prevents the return of the air which is discharged
through the valve F.

The quantity of air exhausted is calculated of course
from the area of the bore of the cylinder, and the length
of the stroke.
Dimensions of The dimensions \rhich I have found sufficient for large
one for large ^orks are as follow :

The bore of the exhausting cylinder two feet.

The length six feet, go as to afford a stroke of foar feet,

Th9

VE^fTILATION OF MINES OR HOSPITALS. 335

The pipes which conduct the air to such an engine oughit
not to be less than six.inch bore.

The best rate of working is from two to three strokes a
rainute; but if required to go much faster it will be proper
to adapt a capacious air-vessel to the pipes near the machine,
which will equalize the current pressing through them.

Such an engine discharges more than two hundred gallons
of air in a minute; and I have found that a stream of water
supplied by an inch and a half bore falling twelve feet, is
sufficient to keep it regularly working.

A small engine to pump out two gallons at a stroke. Small engine.
which would be sufficient in many cases, could be worked
by a power equal to raising a xary few pounds weight, as
the whole machine may be put into complete equilibrium
before it begins to work, and there is hardly any other
friction to overcome but that of the air passing through the
pipes.

The end of the tunnel of the Tavistock Canal, which it Ventilator ap-

was my object to ventilate, was driven into the hill to a f^^®^ !'' ^j^f,
•' •' ' tunnel of th6

distance of near three hundred yards from any opening to Tavistock
the surface, and being at a depth of one hundred and*^^'^^-'
twenty yards, and all in hard schistus rock, air-shafts
would have been attended with an enormous e^tpense; so
that the tunnel being a long one, it was most desirable to
.sink as few as possible, and of course at considerable
distances from each other. Thus a ventilating machine was
required, which should act with sufficient force through a
length of near half a mile, and on the side of the hill where
it first became necessary to apply it, no larger stream of
water to give it motion could be relied on, than such a one
as I have mentioned after the description of the engines;
and even that flowed at a distance from the shaft where the
engine was to be fixed, which made a considerable length of
ronnexion rods necessary.

Within a very short time after the engine began to work, It^ action.
the superiority of its action over those formerly employed
was abundantly evident. The whole extent of the tunnel,
which had been' uiiinterruptedly clouded with smoke for
some months before, and which the air that was forced in
Jaeyer rould dme o«tj ivow became speedily so cl^ar, that the

da/

S3(y YEIfTlLATION Ot MINES OJt IfOiPltALS.

day light and even objects at its mouth were distinctly seett
from its farthest end. After blowing up the rock, the
miners could instantly return to the place where they were
employed, unimpeded by the smoke, of wliich no appearance
would remain underground in a very few minutes, while it
might be seen to be discharged in gusts from (he valve at the
top of the shaft. The constant current into the pipe at the
same time effectually prevented the accumulation of air
unfit for respiration. The influx of air, from the level into
the mouth of the pipe, rushes with such force as instantly
to extinguish the flame of a large candle; and any substance
applied, so as to stop the orifice, is held tight by the out-
ward pressure.

It is now more than two years since the machine was
erected, and it has been uninterruptedly at work ever since,
and without repair. The length of the tunnel has been
nearly doubled, and the pipes of course in the same pro-
portion, and no waut of ventilation is yet perceptible.

Two similar engines have been since constructed for other
parts of the same tunnel, and have in every respect an-
swered the purpose for which they were designed.

The original one is worked by the small stream of water
before-mentioned, by means of a li^ht overshot-wheel twelve
feet in diameter, and about six inches in breast. — The two
othersare attached to the great overshot-wheel, which pumps
the water from the shafts which are sinking upon the line,
and as their friction is comparatively nothing, this may be
done in any case, m ith so little waste of power for this pur-
pose as not to be an object of consideration, even if the
power be derived from more expensive means.
Its appVicatkin The size of the exhauster may always be proportioned to
to various pur- ^y^^ demand for air, and by a due consideration of this cir-
cumstance, this engine may be effectually adapted not only
to mines and collieries, but also to manufactories, work-
houses, hospiials, prisons, ships, and so on.

Thus, if it were required to ventilate a shaft of a mine,
or a singlejevcl, which is most frequently the case, where
three men are at work at one time, and we allow that those
three men vitiate each twenty-seven cubic inches and a half
gf air per minute, (as determined by the experiments of

Messrs^

TENTILATION OF MINES OR HOSPITALS, - 337

Messrs. Allea and Pepys); and allowing farther, that their
candles vitiate as much as the men, there will be six times
twenty-seven cubic inches and a half of air to be drawn out
in a minute, equal to one hundred and sixty-five.

Now a cylinder five inches in diameter, working with a
stroke of nine inches, will effect this by one stroke in a mi-
nute, though it would certainly be advisable to make it
larger.

'■ Not being practically acquainted with collieries, or mines Its application
that suffer from peculiar gasses that are produced in them, '

I cannot state, from actual experiment, what effect this ma-
chine might have in relieving them; but it must appear,
I conceive, evident to every person at all acquainted with
the first principles of pneumatics, that it must do all that
can be wished; as it is obvious, that such a machine must in
a given time pump out the whole volume of air contained ia
a given space, and thus change an impure atmosphere for a
better one. And in constructing the machine it is only
necessary to estimate the volume of gas produced in a certain
time, or the capacity of the whole space to be ventilated.
It is easy to judge how much more this must do for such and to fire-
cases as these, than such schemes as have lately been pro-^^"^^'
■ posed of exciting jets of water, or slacking lime, both of
which projects, likewise, must fail when applied; as one of
them has, I believe, been proposed to be io the case of hi-
drogen gas. But with such a machine as this, if the dreadful
effects of explosions of this air are to be counteracted, it
may be done by one of sufiicient size to draw off this air
as fast as it is generated; and by carrying the pipes into the
elevated parts of the mine, where from its lightness it would
collect. If, on the other hand, it is desired to free any sub- orchoke-damp;
teirraneous work from the carbonic acid gas, it may as
certainly be done by suffering the pipe to terminate in the
lower parts, whither this air would be directed by its gravity.

In workhouses, hospitals, manufactories, &c., it is always to workhou<:efj,
easy to calculate the quantity of air contained in any j^uf^^^^^^'-gg^^i^
room, or number of rooms, and easy to estimate how often
it is desirable to change this in a certain number of hours,
and to adjust the size and velocity of the engine accordingly.
Where this change of foul air for pure is to take place in

Vol. XXIX.— Supplement. Z th^

338 " VCXTIULTION OF MINES OR HOSPITALS.

the night, means for working the machine may be provided
by pnraping tip a quantity of water into a reservoir of suffi-
cieat height to admit of its flowing out during the night in
a small stream, with sufficient fall, so as to give motion to
the engine; or by winding up a weight of sufficient size;
or by nsany other means, which are easily devised.

If, for instance, a room in which fifty persons slept was
eighty feet long, twenty wide, and ten high, it would con*
tain 16000 cubic (eet of air; and if this was to be removed
twice in eight hours, it would require a cylinder of thirty
inches diameter, working with a four-foot stroke four times
in a minute, to do it; or nearly that. Such a cylinder
, could be worked by the descent of ten gallons of water ten
feet in a minute; or, for the whole time, by eighty hogs-
heads falling the same height.

But this is a vast deal more than could be required, as the
fifty people would, in eight hours, only vitiate three thousand
gallons of air, which could be removed by one hundred
and fifty strokes of a cylinder, twelve inches diameter, with
a four-feet stroke, which would ^ot require an expenditure
of more than one thousand five hundred gallons of water
properly applied, or about twenty-eight hogsheads.

JOHN TAYLOR.

Holwell, near Tavistock,
. Feb. 7, 1810.

Certificate.
Te^imony of An extract from the Report of the Committee of Manage-
itsefficsicy* tnent of the Tavistock Canal, to the General Meeting of
Proprietors, held in August 1808, stating, that great im-
pediments had arisen from the want of good air in the tun-
nel when distant from a shaft, then adds — " For the purpose
of rendering the ventilation in the tunnel completely good,
and of doing it in a manner that maybe applied to very
considerable lengths in driving, the engineer has erected
machines, acting upon the simplest principle, and without
friction, which exhaust from the very place in which the
men are working a continued volume of vitiated air; the
place of which, of course, is as constantly supplied with
fresh air, by the pressure of the atmosphere, and thus all
difficulty oa this head completely ceases."^

V. On

INDELIBLE WRITING INK. 339

V.

On the Processes emnloi/ed to cause Writing to disappear
from Paper f to delect the Writing that has. been iuhstU
iutedj and to revive that which has been made to disap-
pear; Improvement of common Ink; a Notice of a new
Inky that resists the Action of chemical Agents: by B.
H. Tarry, M, D. *.

W RITING is removed either by scraping with a knifcj Indications of
or by means of acids. When writing has been scratched ^^^^^"1.^^^^ '
out, commonly pounce, or size, is applied to the paper, out.
that the ink afterward used may not run. If pouncevhave
been employed, the strokes of the same pen will app^r
more slender, if size more fuU, than on other parts of the ^
paper. Immersion in warm water for a few minutes will
dissolve and wash away size: alcohol will have the same
effect on pounce. After the paper is taken out, it should
be dried slowly; at first in the shade, till three parts dry,
and afterward between the leaves of a book, or a quire of
paper. While it is drying the ink last used will spread and v

sink into the paper more or less. Generally indeed close
inspection with a good lens will show where any writing has
been scratched out, by the appearance of some loose or
torn filaments.

If the means employed to obliterate Writing have been If all the iron
such as to remove the whole of the iron from the P^P^r, ^^^^^ ,^t" '^^^
every attempt to restore the writing must be vain. If some writing cannot
ferruginous compound remain, the characters maybe re-^^'^^^^°
produced in their original form; though the colour, will
vary, according^ to the nature of the compound in which
the iron is concealed, and of the reagent employed.

In some cases the gallic acid is capable of recomposing Sometimes it
the writing, that has been made to disappear by chemical ^^^^1^,^^^.^'^®
means; but its attraction for the oxide of iron is not so
f> strong as is commonly supposed. The red or brown oxide
of iron, obtained from the sulphate or nitrate hy means ©f

• Abridged from the Ann. de Chim. vol. Ixxiv, p. 153; and
from the report made to the Institute by BerthoUet, Vauquelin>
and Deyeux, ib, vol. Ixxv, p. 194.

Z 2 . alkaline

340

prussiateof
lime or po-

hidroguretted
alkaline sul»
phurets.

INDELIBLE WRITING INK.

alkaline carbonates, cannot combine with the gallic acid to
form ink, unless the carbonic acid have been expelled from
the oxide of iron by some more potent acid. It is the
same with respect to the oxalic acid, and acidulous oxalate
of potash: when this acid or this acidulous salt has seized
the oxide of iron, the gallic acid cannot destroy the com-
bination, because it has an inferior attraction for the oxide
of iron.

If the writing have been destroyed by nitric or oximu-
riatic acid, the gallic acid in tincture, infusion, or decoctioa
of galls will revive it.

Liquid prussiate of lime or potasb is a good re-
agent, to detect the presence of iron. If the ink have
disappeared in consequence of the decomposition of gallic
acid, as when oximuriatic acid has been employed, either
tof these will render it legible, causing it to appear of a
fight greenish blue Awhile wet. If oxalic acid have been
employed to obliterate the writing, the prussiates will re-
store it of a reddish brown colour. If nitric or sulphuric
acid have been employed, the prussiate of lime will shovir
this by staining the paper blue, but it cannot reproduce the
Writing.

Hidroguretted sulphurets of the alkalis, or of the al-
kaline earths, are very prompt and powerful tests of fer-
ruginous salts. The alkali, or earth, combines with the
acid; and the sulphuretted hidrogen with the oxide of iron,
forming an hidroguretted sulphuret of iron. Iron in the
State of red oxide is partly disoxidated by the hidrogen,
water is formed, and the iron passes to the state of black
oxide. This is the case with writing turned rusty: these
reagents immediately change it to a green black, much
deeper than gallic acid would give. A solution of sulphatd
of iron mixed with an hidroguretted sulphuret produces a
very deep green black ink.

The same attractions are exerted when the hidroguretted
tests are applied where writing has been obliterated by the
oxalic acidule or the oximuriatic or nitric acid. If the
oxalic acidule were employed, the characters will reappear
of a green black or brown red. If the oximuriatic acid,
of a green black or pale rust colour. The less the revived
writing approaches a blacky the more the iron w^s oxided

INDELIBLE WRITING 1N4» 241

in the metallic salt decomposed, or the less the iron was dis-
oxided by hidrogen. The writing on which nitric acid has I»»^ifations of
acted strongly cannot be reproduced: but on passing snl-J^^^J^f^y^-^j^
phuretted hidrogen over the paper where it was, waTingacid.
iincs of a green black will be formed on the remotest parts
to which the sulphuretted hidrogen penetrates. These lines
may be produced in great number, and in different direc-
tions. They are owing to the sulphuretted hidrogen com-
bining with the oxide of the ferruginous nitrate. If the un-
dulating lines, or the letters that haye been restored, shonld
disappear, they may be reproduced by dipping the paper into
cold water. Beside the traces of writing, and the nndnlat-
ing lines just mentioned, the paper takes a yellow colour
wh€^ it is not impregnated with an acid, and a green more
or less deep when it is. The green colour will be deeper,
in proportion as the acid was stronger, or in larger quantity.
In all cases the paper retains the colour of fresh butter after
it is dry. The hidroguretted sulphurets should be diluted
'with half or two thirds their quantity of water before they
are used, as in their ordinary state they are too strong.

From what has been said, we may hope to restore writ- Method of re-
ing, that has been obliterated by any agent except the nitric ^^^'^JJ^j^J^J^^^
acid ; and if this have been employed only in small quantity,
without the assistance of any other acid, audits action has
not been t«o long continued, on holding the paper to the
fire the writing will reappear of a rust colour.

With regard to the improvement of ink, little progress Improvement
has been made since the time of Lewis. Inks made by in- ® ^^ •
fusion, and with green sulphate of iron, are of a Prussian
blue colour, light, pale when written with, but growing
black as t\\ey dry on the paper. Those made by decoction
are blacker, thicker, and form a more copious sediment,
which is of a dirty Prussian blue colour. Decoction ex-
tracts from galls all the soluble parts ; infusion takes up
chiefly the gallic acid, aad mucilage, with a little extract
and tannin. In the decoction the iron of the green sulphate
becomes more oxided, and the extract and tannin acquire
oxigen, by absorption from the atmosphere; and the iron '
in a higher state of oxidation, and the oxigenized extract,
produce a deeper black with the gallic acid and tannin.

Thft

342

INDELIBLE "WRITIN& INK,

The more abundant sediment is owing to a larger quantity
of extract and tannate of iron. In inks made by infusion,
the oxide of iron, extract, and tannin, increase their oxi-
genation ^ery little, till they come to dry on paper. Nitric
acid immediately obliterates writing with ink made by in-
fusion, but that which has been made by decoction resists
its action much longer, on account of the larger quantity of
. extract in it.
Infusion or de- In proportion as the infusion or decoction of galls grows
should be kept ^^^f its surface is covered with mother, which is the muci,.
sometime. laginous principle separated. This mother ceases to form
in about a year, during which the pellicle produced on the
surface should be removed three or four times. The in^
fusion or decoction of galls grows brown as it becomes oxi-
genized, takes an amber colour, and emits a pleasing smell ;
and, when combined with green sulphate of iron, no longer
produces a Prussian blue, but a green black. The amber
colour of th,is infusion or decoction is owing to the oxige-
nized extract and tannin. The green colour of the ink
arises from the mixture of the black of the gallate of iron
with the fawn colour of the oxigenized tannin, which in
this state can no longer combine with the oxide of iron. If
the tannin be separated from the infusion or decoction by
means of an alkali, the green or red sulphate of iron forms
-with it a very black and purer ink ; and the alkali in the
solution facilitates the union of the oxide of iron with the
gallic acid, by combining with the sulphuric acid of the sul-
phate. The oxigenized extract concurs in rendering the ink
blacker, as does the oxide of iron more highly oxided.
Infusion of galls is preferable to the decoction, as it dis-

Infusion pre-
ferable.

Receipt for
good ink.

solves the principle, that is essential to the composition,
and very little of those that are foreign to it. Logwood
browns the ink, and loads it with its colour; it is better
therefore, to use in its stead a small quantity of galls in ad-
dition to that directed by Lei^is. The following is the Qomr
position of a good ink.

Infuse in one litre [a wine quart] of rain or river watef
1^5 gram. [4 oz. troy] of bruised galls, letting them stand
in the sun four hours in summer, or six hours in winter.
This infusion may be used immediately after straining; but

' ' ■ ■ ' H

I

a is better to let it stand four or six montfe, removiirg {he
mother that forms on the top novr and then, and ffnaKj se-
parating by filtration both this and tbetannio that has faWen
to the bottom. In this dissolre 32 gr, [a troy oumrej of
powdered gam arable ; then add the same weight of finefjr
powdered snlpbate of iron, snpepoxigenized by calcining it
iitl it grows reddish ;-aDd continoe shaking the mixture til!
this is completely dissolved. The ink thus made }s fine,
light, and of a purple tinge, but black when dried on the pa-
per. It is nearly, if not precbely, the composition of Gayof^s
ink.

Dr. Tarry next proceeds to his indelibfe ink, the compo- lacJeTible iak»
sition of which howerer be does not dis^close. He says
.only, that it contains neither galls, nor Jog^f ood, nor bra-
zil, nor gum, nor arty preparation of iron ; that it is en-
tirely Tegetable ; and that it resists the action of the rao&t
powerful acids, of alkaline solutions in their most eoncew-
trated state, and of all solvents. He sells it in a solid form ;
and for use it is to be mixed accurately in a mortar with
eight parts of water, and then put into a bottle left at least
one third empty, for the purpose of shaking it, which is to
be done every six or eight hours for a couple of days. It
soon soften quills, but metallic j>ens are well adapted to it,
as it contain^ no acid. There is no danger from putting the
pen into the mouth, as it cootains nothing deleterious. .

Nitric acid has very little action on this ink. Oximu- Action of ad&
riatic acid only changes it to the colour of goose dung.
After it has been acted on by this acid, caustic alkaline
solutions give it the colour of carburet of iron. The letters
however still remain unchanged in form, and these effects
require a long maceration for their production.

From the i^eport of the committee it appears, that the Report of the
ink of Dr. Tarry possesses the properties he ascribes to it ; commUtte.
but they add, it has one of th& faults common to all
the indelible inks proposed, that of pretty quickly forming
a considerable sediment, which deprives the supernatant
fluid ofits properties, so that it requires to be shaken erery
time it is used.

VI. a»

and alkalis
oa It.

344

SENSE OF SMELL IN FISUEf.

YI.

On the Sense of Smell in Fishes : By M. C. Dumerll*.

but this ques
tionable.

Fundamental
propositions.

hlad? of fishes Almost all the fishes hitherto observed have nostrils f .

called nostrils. At least this name is given to two deep holes, which are ge«

nerally found in the heads of these animals between their

eyes and lips. These cavities have a single slender orifice ;

and within they are lined with a mucous membrane, having

numerous folds. The first pair of nerves from the braia

enter into the substance of this membrane, ramify in it,

Supposed to be and there terminate. Analogy therefore seems to indicate,

the organ of ^j^^j ^j^g nostrils of fishes are particularly intended for the

organ of smell, as in all other animals with vertebras.

Against this opinion however, adopted by all naturalists

and physiologists, I have some facts and reflections io

offer, which perhaps will seem more consistent with our

knowledge in comparative anatomy and physiology.

I propose to show, that the organ of smell does not and
cannot exist in the mouths of fishes, from their manner of
breathing: that the organs, hitherto considered as adapted
to the sense of smell in these animals, are intended for the
perception of a sensation analogous to that of taste: and
that there can be no true smell for an animal habitually im-
mersed in a fluid.
"Nerves of sight, In animals with vertebrae, anatomy easily distinguishes
^^*""S) a.n^ among the nerves, that lead to the organs of sight, hearing,
guishedj and smell, the trunks of those peculiarly intended to trans-

but not those of mit the sensation : but it is not the same with the organ of
taste. We know indeed, that, at least among the mammalia,
thegustatory faculty resides in the surface of the tongue: but,
as this fleshy substance has other functions, and as its move-
ments are particular!}' connected with the organs of speech
and deglutition, it receives several nerves, and these greatly
ramified, proceeding from three different regions of the
brain. Hence anatomists have not been able precisely to

♦ Mag. Enc. Sept. 1807, p. 99. Read to the Institute/ All.
gust, the 24th.

t Except the cyclostomes, as the lampreys and sphagobranr
chix, which are not real fishes, as I shall show elsewhere.

determine.

taste.

Different
nerves
lead to it.

8EN8E GF SMELL IN FISHES. . 345

determine, whether the sensation be imparted through the
medium of the lingual branch of the fifth pair, that
of the glossopharyngean, or that of the great hypoglossal
nerve.

It is true the majority agree in considering, the lingual The general
«,.«. ... jl 1 opinion in fa-

branch of the inferior maxillary nerve as the only one capa- vourof a branch

ble of transmitting the sensation of taste ; and most of them ad- of the lower
duce in support of theiropinionthe observation of Colombo, j^ej.^.g^
■who did not find this branch in a man destitute of the sense
of taste. Soemmering, however, questions the circumstances
of this fact, as well as of a similar one cited by Rolfink.

On the other hand some physiologists, at the head of Others for the
whom is the great Boerhaave, have ascribed the g"siatory ^^^^^^^^^gP^^ "^
faculty to the great hypoglossal nerve. These too rest
their opinion on some anatomical observations, particularly
on a case in pathology quoted by Hevermann, where the
sense of taste was destroyed on the extirpation of a gland,
with which the nerves, called at that time the great gusta*
tory, or ninth pair, were removed.

The particular subject of physiology and comparative
anatomy before us, therefore, may throw some light on a
question not yet completely resolved.

Though the sense of taste is essentially necessary to ani- xhe sense of

mals, and must be the last obliterated, since on its decisions t^^te necessary

, , . ,. 1 . ... .1 • ,. , to animals:

depend their preservation, by instructing them m the nature

pf the substances proper for their food, and the selection of

them; at first sight, however, it would appear, that fish but fishes appa-

are destitute of it, if we seek for this organ in the parts Qf"|.^

where it is commonly seated.

In fact the inside of the mouth in fishes is lined with a as it cannot re-
thick, smooth, and polished membrane ; of a very close ^^^uth
texture, resembling that of the skin ; and most commonly
of the same colour with it. Sometimes this membrane is
completely detached from the bones of the palate, or re-
tained merely by a few vessels ; as I have observed in the
cod, frogfish, bullhead, ray, and shark: and I have never
fceen in it papillas, or salivary glands.

The tongue of fishes is seldom movable. A bone sup- or tongue,
ports it throughout its whole length. Its point can neither
turn backward^ nor toward the sides. In general the lips,

palate.

46 SENSE or SMELL IN FISHES.

palate, *ongne, and branchiostegous rays are coTcred with
bony points, or laminap of different forms, which prcTcnt
the intimate contact of substances taken into the mouth. It
is true in the muscles of the hyoides and of the branchios-
tegous rays, placed at the lower part of the mouth, we find
all the ramifications of the nerves of the fifth pair, as well as
those of the indeterminate nerve, which evidently has the
''"he great hy- place of the glossopharyngean. Yet neither I nor Mr.
^*zmtinc in '^^^ Cuvier conld ever meet with the great hypoglossal nerve
them. ill fishes, notwithstanding our most attentive sear(5hes, when

I enjoyed the advantage of editing his lectures on compara-
tive anatomy. Besides, as .this fact was of great importance
to tht subject of the present paper, I think it proper to
add, tliat I have again satisfied myself of it by fresh ana-
tomical researches.
The sensation It is easy to imagine, that the water, by its continual en-
d^ ^A^ "j^outh France into the mouth, and the compression it there under-
goes, as often as the fish exerts on it the action of degluti-
tion necessary to force it through the gills, must exert a
friction so often repeated, as to deaden all the sensibility of
these parts.
ancl the orgnn Now since the integuments of the inside of the month are
oftastccannot coriaceous, destitute of salivary glands, and frequently-
roughened with teeth' or horny points ; the tongue adherent,
bony, and immovable ; the great hypoglossal nerve want-
ing; and water continually exerting a friction on it: it is
very probable, that the organ of taste cannot exist there.
This was the first point I proposed to examine.
Probably it is As the organ of taste appears not to reside in the mouths

in some other f fishes, and this sense is indispensable to animals, we must
part. '

meet with it elsewhere: and since tastes in general bear a

considerable analogy to smells, let us inquire whether the
sense of smell be not to a certain degree converted into that
of taste. But, before we enter on this investigation, let
us examine the nature of these two sensations.
Nature of Natural philosophers, chemists, and subsequently phy-

smells, siologists, have generally attached to the idea of smell, that

of the sensible existence of corporeal atoms of extreme mi-
nuteness. Though art has not yet been able to imitate au
instrument so perfect as that met with at the entrance of the

respiratory

SENSE OP SMELL IN PISHES. 347

respiratory organ in animals that live in the air, we hare

some means of proving chemically the material existence of Proof*; of their

those smells, the nature of which is best hnown. Thus the "^^^^,^'^'^^-

exhalations from nitrous gas, volatile oils, and ether, for

example, may be destroyed by the combination of some of

their principles with oxigen ; and muriatic acid gas renders

sensible to the eye the particles of ammonia, which cease

to be odorate the moment this acid combines with them in

the open air.

The most perfect animals, those that possess all the five Senses of per-
scnscs, are so organized as to perceive the principal modifi- ^ctammas.
cations of the bodies surrounding them. They have sight,
to enjoy the effects of light; feeling, to appreciate the soli-
dity of palpable objects ; hearing, to distinguish the vibra-
tions of elastic bodies; taste, to discriminate the qualities
of bodies capable of becoming liquid; and lastly smeJl, to
collect the emanations of substances, that have the proper-
tics of a gas.

Light exerts its action only on the eye ; not on the tongue, Each sense has
postrils, ears, or skin. It is the same with most smells, jg^t,
which do not act on the sight, taste, hearing, or touch.
Each of the organs of sense then has its particular function, dependent on
jSxed and determined beforehand by the arrangement of its^ e organ,
apparatus i for the sentient principle appears to be ideuti- as the sentient
cal, and placed, as we may say, on the watch on the inside ^'""^'P ®^''***
of each instrument, in order to collect and transmit the
slightest modifications in the qualities of bodies. ^

The sensations of smell and taste however, are most ana- Smell and taste
Jogous, both in respect to the mode of action on our bodies, ^7^^°a"loer'
and to the apparent end at least for which nature seems to
have given us organs to perceive them. The odorate and
sapid particles are conveyed either by the airs that serve for
respiration, or the solid and liquid aliment that must enter
the stomach. Stopped on their passage through the nostrils
or the mouth, these particles touch the nerves distributed
on those parts, and thus give notice of their presence. The
jierve^ immediately excite the ideas of the sensations they
perceive, and excite us to admit or reject the air or food,
according as the impression produced on the organ is agreea-
])le or not. The sapid and odorate qualities of bodies then

are

348 SENSE OF SMELL IN FISHES.

are discriminated by the tongue, when they are contained

in a liquid ; and by the pituitary merabrancj when they are

suspended in a gas.

Smell peculiar From these general considerations of the nature of smells

to the stale of and tastes, it appears, that liquids cannot intrinsically possess

smell, since this quality of bodies is inherent in their state of

and cannot be gas, or vapour. We are justified therefore in presuming,

Equ d^^*^ ^^ ^ *^^* ^" animal, which from its nature must be immersed ia

a liquid all its life, does not possess a sense of which it can

make no use : and this is the case with cetaceous animals,

fishes, most of the molluscae, a great number of crustaceous

animals and worms, and all the zoophytes.

Cetaceous tribe In a former paper I have pointed out the analogy be-

analogous to . ^ , , ^ . , . , , ,

fishes in their tween nshes and cetaceous animals, with regard to the me-

mode of respi- chanism of respiration*. It is in consequence of this mode

' of respiration, if I may so say, and of their necessary abode

in water, that the organ of smell appears to be annihilated

in these animals ; for as Daniel Major and John Hunter

first observed, though only in a few species, and Cuvier

has since shown generally and more at large, there are no

and want the olfactory nerves, and no ethmoidal foramina, in the ceta-
oUactory nerves. •' nii . ,

ceous animals. Ihe pituitary membrane, that lines their

nostrils, is smooth, dry, and coriaceous : it appears to
have become insensible from the constant friction on it
ocsasioned by the rapid and violent action of the water,
that pervades the cavity of the nostrils. It appears how-
ever, that the organ of taste here supplies the place of that
of smell; for, by a slight modification of the organs, the
These nerves olfactory nerves of fishes may have another use, and be

huTe another ^ggtine^ to make them sensible of tastes.
\ise 111 fishes.

Though fishes From the ideas we have formed of the nature of smells, it

cannot smell, necessarily follows, that fishes cannot receive impressions

similar to those they occasion in animals that breathe air.

they are sensi- Yet we know, that fishes are attracted by the emanations,

blc of emana- ^j^^^ escape from several substances immersed in water, as
tons from sub- , i . /> , . i_

stances. is demonstrated by various baits employed in fishing ; the

salted roes of cod and mackarel, the broiled or stinking

flosh of certain animals, old cheese, and many other things

of strong ^mell.

* See Journalj vol. xxviii, p, 355.

Aristotle

SENSE OF SMELL IN FISHES. 349

Aristotle was acquainted with most of these facts, and even This known to
recite^ them at large in his History of Animals: yet he-^"^^^'^
says positively, " fishes have no distinct organ of smell, for
there is but one orifice to the apertures they have in the
place of the nostrils." And elsewhere, " we see in them
no external organ of hearing or smell, not even an aper-
ture.'* Mr. Schneider, in his Synonimes of Artedi's
Fishes, reproaches Aristotle with entertaining this opinion,
after having so well described the olfactory organ and nerves
in these animals. It is in some measure therefore a defence whose opinioa
of Aristotle's opinion, if I endeavour to show, that every '^ ^^^ ^ '
emanation in water must produce on the nerves, with
\^hich it comes into contact, a sensation analogous to that
of taste.

Since there are no real smells in water, the exhalations, The organ of

that escape from bodies immersed in it, either rise to the ^"^^'^ ^°"J*^, '^
/ ' useless to nsh«.

surface in the form of gas, and consequently do not re-
main in the liquid; or they are suspended in it or combined
•with it, and they participate in all the properties of liquids.
If however the qualities of these particles, thus dissolved,
be perceptible, they necessarily come under the same cir-
cumstances as sapid bodies ; and therefore it would be use-
less for fishes, which live habitually in water, to be en-
dowed with the organ of smell.

To prove the accuracy of this reasofiing, it is necessary Use of the ner-

to investigate the use of the nervous apparatus, which has ^'°"^ apparatus

rr 7 supposed to be

hitherto been supposed to be intended for the perception of intended for

smells: and to this I shall proceed, treating it more mi- ^™*^^^'"S*

nutely than in the beginning of this paper.

The. cavities termed nasal are always situate before the The nasal ca-

eyes, in the space between the nasal bones and those of the^'^^f* 5*®"

•',._., . ^ scribed.

Upper lip. Sometimes they are m the substance of the

bones of the nose themselves, or between these and the

pieces which Artedi has called hypophthalmic. The he-

terosome fishes, as the pleuronectes, the only animals with

vertebrae that are not symmetrical, are the only ones that

have both nostrils on one side of the body, in some on the

right, in others on the left, and unequal. Lastly, though

most of these species have these cavities on the top of the

head, in ihe^ forehead; they arc found beneath, and most

frequeuily '

350 SENSE OF SMELL IN FISHES.

frequently communicating with the mou<h, in all the j^lk^
giostomes, as the ray, the shark, &c.

In all fishes these cavities present a kind of sinus, or
cul-de-sac with a narrovr opening; most commonly divided
into two portions, sometimes into three, as in the eel, by
a membranous septum, variously convoluted, which icthyo-
logists have frequently noticed as characteristic of species.

We know from the observations of Monro, that these
valves or curtains may be moved according to the will of
the animal; and that under certain circumstances the orifice
may be nearly covered by the septum. It is easy to ob-
serve this in live fishes, as I have seen in the goldfish and
stickleback. It is then apparent, that the motion of the
septum seems to be the consequence of the protraction of
the lips; since at each inspiration *the catity opens and di-
lates, while it contracts and is covered as often as th6
mouth is closed: whence it seems to follow, that at every
inspiration the fish causes a small quantity of water to enter
on each side, which it may be said thus to analyse.
The first pair Each of these perforations exhibits within a cavity, very
of nerves and spacious in proportion to its orifice; and on this is spread
part of the 5ih f .. / u , .x». • i. r. \

spread on the the sentient membrane covered with mucus, in the substance

menibrane of which is expended the whole of the first pair of cerebral
nerves, and one or more large branches of the fifth pair,
according to the observation of Collins quoted and cor-
rected by Cuvier.

iThese cavities Nor must I forget to remark, as a circumstance particu-

are always se- j^rly deserving notice, that these pretended nasal cavities
parated from -^ ^ * ° ,' , ,^ .. ,

the respiratory are always separated from the canal of respiration* and

^i^^^» that it is only in the rays, and some neighbourirtg genera,

which have spiracles, that they are observed almost in the

mouth. In fact it is to be presumed, that the liquid, in

traversing them, would have deadened the sensibility of

their surface by the rapidity of its motion, and the friction

of its particles.

Wh^tarethe Now are these peculiarities of structure, which I have

inferences from mentioned, of such a kind as to lead us to abandon our

first opinion, deduced from the knowledge of physics, that

smells cannot be perceived in water? or is not this supposed

organ of smell in fishes better adapted to excite in them the

sensation

SEffSE OF SMELL IN FISHfeS. 351

scrtsation of tastes? These questions I shall proceed to
examine.

Tastes and smells are nearly of the same nature: both Tastes and
sensations are produced by the physical and chemical quali-^'^^^^^ analo-
ties of bodies. We know, in fact, that very minute par- .
tides arc continually separating from certain substances,
which, without being decomposed, come to act immediately
upon animals at that point of their surface alone, where
they can manifest their presence. This phenomenon is
effected by the intervention of a fluid medium, and a sort
of contact*.

All the conditions necessary for the impression or sensa- The organs ia
tlon of taste are united therefore in the organ under exa- fectl^"^ia^^ ted
mination, and the nature of the substances that may pro- to the sense of
duce it. First, the organ is placed secure in a cavity: ft^^^^^*
opens and shuts at the will of the animal, it admits or re.
jects emanations at pleasure. Secondly, the sentient sur-
face receives numerous and bulky nerves from the fifth pair;
it is soft, moist, atid mucous ; and it presents a great sur- ^
face in a large space. Thirdly, it appears in a certain de^
gree to supply the place of the organ of taste, which
cannot exist in the mouth of fishes from the very mechanism
of their respiration.

It seems to follow then from all these circumstances, that General con-r
the organ of taste in fishes does not reside in the mouth : ^ "^^°^^^"
that the sensation of taste is probably imparted to them by '
the apparatus, which has hitherto been considered, as
adapted to perceive the emanations of odorate bodies: and
Lastly, that no real smell can be. perceived in water.

* I have already had occasion to enlarge on these general ideas
in a paper on the organ of smell in insects, ^'i)ich I published ten
years ago, and which may be found in tJie second volume of the
Magazin Encyclop^dique, p. 435,

VII. On

353

ALUM MINES OF AUBIN.

Alum mines
of Aiibin.

from coal-pits
that have
taken fire.

Description of
the coal
country.

Its structure.

VII.

On the ,Alum Mines of Aubin in the Department of the
Aveyron; by Mr, L. Cordier, Engineer in chiefs <^c. *

T

1. HE alum mines of the country of Aubin differ from
those of the same nature worked in other places: their
existence is wholly contingent. The periods of their for-
mation are known, and are very recent. They occupy no
considerable space of ground, and cannot extend much
farther. Lastly their duration must be very limited,
whether they be worked or not. These mines are nothing
but coalpits, that have taken fire within a certain distance
of time, and in which the fire is still daily exercising its ra-
vages. There are four of them; those of Lassale, Fon-
taines, Budgne, and Bourlhones. To give an idea of their
situation, that of the coal in the country must be known.

The territory of Aubin is very hilly, and intersected by
deep narrow passes. The part to the north-east of the
town consists entirely of coal country, and is the least
elevated, being nearly in the form of an elliptic basin, the
great axis of which is north and south, and the surface of
which exceeds a square myriametre [24676 acres]. This
space is skirted and overtopped on all sides by the primitive
soil; and is occupied by a pretty considerable number of
oblong hills, intersected in every direction, and crowded
together. The highest, for they are unequal in this respect,
are two or three hundred metres above the valleys.

The arrangement of the strata throughout the basin ex-
hibits nothing constant, or continued. Independent of the
interruptions occasioned by the narrow passes and valleys,
the direction, inclinafion, and order of the strata vary
from one hill to another; so that to depict the present
state of the soil, it is sufficient to say, that it appears to be
the result of a complete disruption. We can merely per-
ceive, that the directions more frequently approach the me-
ridian than any other line, and that the prolongation of the

•Abridged from the Journal des Mines, vol. xxvi, p. 401.
From the Report made to the council of Mines in 1807.

strata

ALUJt MINES OF AUBiy. 333

itrata is almost always in the longitudinal direction of the
hills. As to their dip the strata are generally set on edge:
they hang in all directions, and at every possible angle from
perpendicular to horizontal : the strata of two neighbouring
hills are seldom seen to incline the same way ; and, when
this does occur, it is at different angles. The hills nearest
together offer striking varieties, and frequently singular for
the nature, order, and thickness of the strata. It is even
in vain to seek for some similarity of structure in certain
places, -where the strata that skirt a Valley are placed so,
that they would come to rest against the strata on the other
•ide, if both were sufficiently prolonged. Hence it may be
conjectured, not only that the surface has been completely
broken up, but that it has experienced considerable degra-
dations subsequent to this disruption.

The coal ground is almost wholly formed of a gray sand- Strata,
itone, commoly fine-grained, and composed of feldspar,
quartz, and some particles of mica. The mean thickness
of the strata is about a yard: some are found, that are
more than ten yards thick, others not a tenth of a yard.
In the midst of these sandstones are seen thick strata of
puddingstones with granitic fragments ; and strata, generally
thin, of gray or blackish argillaceous schist exhibiting some
impressions -of vegetables. Coal is found throughout al*The coaL
most the whole of the basin. The outcroppings are very
numerous, and occur indiscriminately at the foot, on the
acclivity, toward the summit, or on the ridges of the hills.
The number of the seams, their thickness, and their dis-
tance from each other, vary in every hill. They are al- /
most all thick enough to be worked. There are seldom
more than four in one hill. Their mean thickness is in ge-
neral from two to six yards; but in some places it is truly
astonishing, and hitherto unexampled. The vertical seam
now working at Lassalle is 103 met. [338 feet]. Its course
is perfectly regular, and known, for it is worked by means
of levels extending from the roof to the wall.

From what has been said it is obvious, that the coal of Management
this country is as easy to extract as it is abundant. It is °^ ^^*
worked in fact in a number of places, and almost every
where by means of levels. The coal is embarked on the

Vol. XXIX. — Supplemext. A a river

354:

ALUM MINES OF AUBIN.

The works
that have
been relin-
quish etl take
fire spontane-
ously.

Four of these
only deserve
notice.

river Lot, which runs near the mines. But this uniott of
natural advantages, far from being turned to profit by good
management, has hitherto given rise to various abuses ;
though I shall only point out that, which relates to the sub-
ject of the present paper. From time immemorial every
landholder has been at liberty to dig in his own ground, get
out the coal without order or method, and dispose of it as
he could. Hence the number of pits opened has had no
reference to the demand, and frequently individuals have
been obliged to relinquish their works for want of a sale
for their produce. Now from causes which it is useless to
discuss here*, the works. that are thus given up ^re liable
to take fire spontaneously, even when carefully watched.
The fire communicates very rapidly every where ; and if the
greatest exertion be not made to stop it in the beginning, it
becomes afterward impossible to check its ravages, and the
work is destroyed. It appears, that this misfortune hap-
pened very often formerly; for, on going over the surface
of the ground occupied by the mines, at almost every step
we meet with very evident traces of subterraneous fires
now extinct. Accidents of this kind are now more rare, either
from the people having learned how to prevent them, or
knowing how to check them : yet seven or eight works are
still burning at this moment.

Among these works that have caught fire, those called
Lassalle, Fontaines, Bu^gne, and Bourlhones, are the
only ones remarkable, either on account of the intensity of
the fire and the space it occupies, the disruption andtorre-
faction of the earth as far as the surface, or the daily pro-

the coal.

* In general only the purest efeal is got out of the works. That
which is mixed with schist, being of no value, it is used with other
Spontaneous matters to fill up the vacuities made. Now whether this be fre-
combustion of quently accompanied with iron pyrites disseminated in it, or per-
haps even contain sulphur in combination, the fact is, that
moisture renders it a very active pyrophorus, in all parts of the
mines where the circulation of the air is stopped. The miners of
the country have but one opinion on the subject: they all agree,
that the spontaneous inflammation of the works is owing to the
action of stagnant water on the refuse left in them ; and that the
fire manifests itself the more speedily, in proportion as the circula-
lation of the air is more slow.

dttctioa

ALUM MINES OF AUBIN. 355

daction of a considerable quantity of aluminous salts amid

the torrefied rocks.

The burning pits, whence the alum works originate, The pits de-

^must be considered as totally destroyed: but the alum pro- stroyed, but

compensated
duced will more than compensate for the loss of the coal, by the alum.

It is known tooy that the fire will go out of itself, as soon
as it has consumed all the masses of fuel, that have been ex-
posed by the levels. It has long been ascertained, that the The fire does

fire does not extend more than a yard into ihe coal left un- not burn mora

^ , , '' than a yard

touched in depth. This is so certain, that the extraction of deep.

the coal from beneath the works burned has been resumed at
Lassalle and Fontaines.

The effects of the spontaneous combustion of the coal are Effects of the
the same in the four alum works. To judge from the stat0 co«ib«stioa.
of the surface of the earth, the fire has not extended beyond
the space that had been worked. The surface has sunk,
cracked, and been deranged, in the manner of volcanic sol-
faterras. It emits a gentle heat, incessantly renewed; it is
bestrewed with very curious produtrtioas of fusion and torre-
f^ction; the crevices emit burning fumes of sulphurous
acid, bitumen, and water; and even flames continually
arise when the fire is consuming a stratum near the surface.
The sandstones and schists, that accompany the burning
seams of coals, are either simply torrefied, or changed into
red, light, and rugged scorias, or violet-coloured, bluish, gray,
and often striped, enamels. The acidosulphurous vapours
attack, deprive of colour, and decompose part of these
products, and frequently reduce them to powder ; and at
their expense are formed the vitriolic saline substances, that
are found in such great abundance, either in the cavities of
the masses, or amid the earth resulting from their decompo-
sition, or on the surface of the ground. The simple or
alkaline* sulphate of alumine constitute almost the whole of
these saline substances. They exhibit themselves in all forms ;
in disseminated particles, discoverable only by their acerb and
styptic taste, in whitish efflorescences, and filamentous and'

* The alkali is probably furnished either by the combustion of
the coal, or the decomposition of the feldspar; which abounds in
the rocks affected by the acidosulphurous vapours.

A a 2 «ilk/

356

ALUM MINGS OF AUBIN.

Th« mine of
Xassalle.

Burning t>iese
twenty years.

The fire now
abating.

Mine of Fon-
laines.

Has burned
these 80 yeart
in different
scams.

silkj masses, in yelloivish mamillarjr incrustations, or ia
confused masses, friable, cavernous, white, gray, yellow,
red, or a mixture o^ all these colours. It may not be su«
perlluous to add^ that the last variety is sometimes met
with in blocks or incrustations weighing several pounds.

Such are the general characters of these alum mines, but
there are particular ones, which ought to be noticed.

The alum mine of Lassalleis in the bottom of a valley,
at the foot of the hill of the same name, two miles north by
west from the town of Aubin. The surface it occupies on a
slope of about 45**, does not amount to 2 hect. [247 acres].
The subterranean fire has not exceeded the limits of the coal-
pit: it occupies the length of 250 met. [273 yards] at the
foot of the mountain, and extends nearly 70 met. [78
yards] into it. It has attacked nothing below the level of
the brook, that flows through the valley.

This pit took fire spontaneously about twenty years ago.
The stratum of coal, which feeds it, was three or four yards
thick, and worked by means of levels. Attempts were made
to extinguish the fire at the time, but in vain. The inclina-
tion of the strata in this part of the mountain is about S*' or
10° W. N. W. ; or contrary .to the slope of the mountain.

The activity of the fire has decreased greatly within these
few years. It appears to be drawing to an end ; or that
the accumulation of torrefied and decomposed substances,
that cover the surface, has retarded its ravages. The effect
of the exavations made within these six months seems to
confirm the latter opinion. Vapours now issue out abun-
dantly by all the new vents they have been able to make,
and the saline efflorescences increase more rapidly.

Thisinine has not been worked above nine months.

The alum mine of Fontaines is at the bottom of the cul-
de-sac, that terminates Ihe valley of Lassalle, and at the
foot of the mountain 2500 met. [2732 yards] N. E. of
Aubin. It takes its name from a hamlet directly above it.
Its surface is nearly square, and may be 3 hect. [370
acres]. The foot of the mountain at this place has a slope
of about BO''.

The fire commenced here eighty years ago. Several
teams of coal were then working, one oTer another, and

inclining

ALUM MINES OF AXJBIX. 357

inclining 35* or 40«' W. S. W. It was got out bymeans of
Jevels, and with so ranch the more ease as the mountaio ^
slopes to the north. Each seam having been worked in sc.
Teral places, and to some distance, as 80 or 100 met., the
£re has made more ravage, than at either of the other
three places. Notwithstanding the length of time, the acti.
▼ity of the fire has not abated, at least in the higher parts. In
fact we see there the sunken surface of the earth iatersected
by long and deep fissures, the sides of which are in the highest
state of incandescence, and from which flames, accompa*
nied with suffocating vapours, are continually escapuig. In
a word, the solfaterra of Fontaines presents the most cu-
rious combination imaginable of all the phenomena above
described*.

The vitrified, scorified, and decomposed matters, that fill
the sp^ce occupied or traversed by the fire, are very rich ia
aluminous salts. „

The alum mine of Buegne is at the top and on the back Mine of
of the hill of Buegne to the east. It is about 2 kilom. [1 1 ^"^i*"**
mile] west of Aubin. It is the result of the spontaneous
combustion of a single scam of coal, which commenced
twenty years ago, and has lost nothing of its activity. This
seam is several yards thick, and runs east and west, as the
ridge of the hill does. Its dip is about 45** south, and
consequently opposite to the slope of the hill. It is
easy to distinguish the outcrops of this scam on the parts

• The aspect of the alum mine of Fontaines, the desolation Difference be-
and broken state of tlie ground, at first view suggest the idea of tween these
volcanic phenomena. But on a more attentive examination wcg canic
perceive, that the earth has been deranged only by s-rnking in ;
that there is no fissure which has any resemblance to the mouth of
a crater ; that the scorification and vitrification have been effected
on the spot; that the products of these two operations do not re-
semble lavas; that the vapours always very evidently contain
Jjitumen, and never muriate of ammonia; that the sal^ formed,
are sulphates ; that besides no detonation is ever heard, and the
groUiUd experiences no commotion that can be compared to an
earthquake: in short, if we set aside the heat and light produced
by the combustion of the coal, and the aqueous and acndosulphu-
rous vapours emitted, nothing similar to volcanic phenomena ever
takes place.

of

hones.

358 , ALUM MINES OF AUBIN.

of the hill uninjured. They run horizontally about a
third of the way down the hill. The works had not been
carried very deep before the fire, but they occupied a con-
fiderable length on the outcrop.

The space deranged and altered by the fire exhibits nearly
an OTal figure. The shorter axis does not exceed 70 met.
[76 yards] ; but the greater, which is horizontal, may be
150 met. [164 yards]. The surface cannot be estimated at
more than 60 ares [148 acres]. The whole of it has ceased
to form a continued plane with the slope of the mountain,
"which is about 40*^ ; and exhibits a depression pretty ex-
actly resembling in figure the stern of a boat. Part of this

, surface is coTcred with solid aluminous incrustations, which

resist the action of the rain in some degree, or are repro-
duced immediately after. It must be a rich mine, though
not at present worked.

Mine of Bourl- The mine of Bourlhones is the least of the four. It is
half way up the hill that faces the mine of Buegne, and
consequently in the same valley. Their distance from each
other in a straight line is about 500 met. [546 yards.]

The fire that formed it has notcontinued above ten years.
It is fed at the expense of a single seam of coal several yardg
thick, and inclining 30^ or 40? east, consequently oppo-
site to the slope of the hill.

The coal had not been worked to any extent, when it
took fire. The combustion has not yet reached its highest
degree of activity. The surface of the ground is partly
covered with grass, partly sunk down, cracked, and torre-
fied. Copious vapours of water, sulphur, and bitumen,
issue from it. Its shape is nearly circular, and it may be
estimated at 30 ares [74 acres]. The aluminous salts are
very abundant, but only in certain places ; though by proper
management their formation may be accelerated in others.
No attempt has yet been made to work it.

Produce of the From the two mines, that are worked by two companies
of adventurers, near 17000 myriagr. [167 tuns] of alum
were made in 1809, which sold for ^abput 120000 fr,
' [^5000].

VII. Th(x

mines.

INFLUENCE OP THE BRAIN ON Tttt ACTION Of THfi ttti-RT, 359

VIII.

The Croonian Lecture^ on some Physiological Researches^
respecting the Influence of the Brain on the Action of
the Hearty and on the Generation of animal Heat, By
Mr, B. C. BiioDiE, F. R. S. *

JlIaVING had the honour of being appointed, by the pre- Influenceof

.1 i. 1 T» I n . i . . ji /^ • 1 i the brain on

sident of the Koyal Society, to give the Lroonian lecture, ^^e action of

I trust, that the following facts and observations will be the heart.
considered as tending sufficiently to promote the objects,
for which the lecture was instituted. They appear to
throw some light on the mode, in which the influence of
the brain is necessary to the continuance of the action of
the heart ; and on the effect which the changes produced
on the blood in respiration have on the heat of the animal
body.

In making experiments on animals to ascertain ftow far Not directly ne-
the influence of the brain is necessary to the action of the
heart, I found, that, when an animal was pithed by di-
viding the spinal marrow on the upper part of the neck,
respiration was immediately destroyed, but the heart still
continued to contract circulating dark coloured blood ; and
that in some instances from ten to fifteen minutes elapsed,
before its action had entirely ceased. I farther found, that,
when the head was removed, the divided blood vessels
being secured by a ligature, the circulation still continued,
apparently unafiected by the entire separation of the brain.
These experiments confirmed the observation of Mr. Cruick*
fihank + and Mr. Bichat J, that the brain is not directly ne-
cessary to the action of the heart; and that,' when the
functions of the brain are destroyed, the circulation ceases
only in consequence of the suspension of the respiration.
This led me to conclude, that, if respiration was produced
artificially, the heart would continue to contract for a
^till longer period of time after the removal of the braii^.

* Philos. Trans, for 1811, p. 36,

f Philosophical Transactions 1795.

J Recherches Physrologiques suf la Vie et la Mort.

360 INFLUENCE OF THE BRAIN ON THE ACTION OF THE HEART.

The truth of this conclusion was ascertained by the follow-
ing experiment.
Exp. I. On a Exp. 1. I divided the spinal marrow of a rabbit in the
muniMdon^cut^P^^® between the occiput and atlas, and having made an
off, and respi- opening into the trachea, fitted into it a tube of elastic
"^^"tifickir"' S""*j *o which was connected a small pair of bellows, so
constructed, that the lungs might be inflated, and then al-
lowed to empty themselves. By repeating this process
once in five seconds, the lungs being each time fully in-
flated with fresh atmospheric air, an arti^cial respiration
was kept up. I then secured the blood vessels in the neck,
and removed the head, by cutting through the soft parts
above the ligature, and separating the occiput from the
atlas. The heart continued to contract, apparently with as
piuch strength and frequency as in a living animal. I exa-
mined the blood in the different sets of vessels, and found
it dark coloured in the venae cavjc and pulmonary artery,
and of the usual florid red colour in the pulmonary veins
and aorta. At the end of twenty-five minutes from the
time of the spinal marrow being divided, the action of the
heart becaipe fainter, and the experiment was put an end to.
No urine With a view to promote the inquiry instituted by the

lecreted. society for promoting the knowledge of animal chemistry

respecting the influence of the nerves on the secretions *,
I endeavoured to ascertain, whether they continued after
the influence of the brain was removed. In the commence-
ment of the experiqfient I emptied the bladder of its con^
tents by pressure; at the end of the experiment the bladder
continued empty.

This experiment led me to conclude, that the action of
the heart might be made to continue after the brain was re-
moved, by means of artificial respiration) but that under
these circumstances the secretion of urine did not take
place. It appeared, however, desirable to repeat the ex-
periment on a larger and less delicate animal; and that,
in doing so, it would be right to ascertain whether under
these circumstances the animal heat was kept up to the na«
tural standard*

♦ Philosophic^ Transactions for J 809. Journal vol. xxvi, p. 135.

Evvt*

INFLUENCE OF THE BRAIN ON tHE ACTION OT THE HEAHT. oc j

Exp. 2. I repeated the experiment on a middle sized dog. gxp.s. Oa*
The temperature of the room was 63« of Fahrenheit's ther- dog.
mometer. By haying previously secured the carotid and
vertebral arteries, I was enabled to remove the head with
little or no haemorrhage. Tlie artificial respirations were
made about twenty-four times in a minute. The heart acted
with regularity and strength.

At the end of 30 minutes from the time of the «?»«»' Action of tli«
marrow being divided, the heart was felt through the ribs heart,
contracting 76 timas in a minute.

At 35 minutes the pulse had risen to 84 in a minute.

At one hour and 30 minutes the pulse had risen to 88 ia
a minute.

At the end of two hours it had fallen to 70, and at the
end of two hours and a hal/ to 35 in a minute, and the
artificial respiration was no longer continued.

By means of a small thermometer with an exposed b"'^? Auimallifi»t.
I measured the animal heat at different periods.

At the end of an hour the thermometer in the rectum had
fallen from 100^ to 94*'.

At the end of two hours a small opening being made ia
the parietes of the thorax, and the ball of the thermo-
meter placed in contact with the heart, the mercury fell
to 86°, and half an hour afterward in the same situation it
fell to 78«.

In the beginning of the experiment I made an openinff ,
into the abdomen; and, having passed a ligature round each secreted,
ureter about two inches below the kidney, brought the
edges of the wound in the abdomen together by means of
sutures. At the end of the experiment no urine was col-
lected in the ureters above the ligatures.

On examining the blood in the different vessels, itwasgiooj^
found of a florid red colour in the arteries, and of a dark
colour ii) the veins, as under ordinary circumstances.

During the first hour and a half of the experiment there ^viuscular coa^
were constant and powerful contractions of the muscles of tractions,
the trunk and extremities, so that the body of the animal
was moved in a very remarkable manner, on the table, on
w^hich it lay, and twice there was a copious evacuation
of faeces.

Exfi

363 INFLUENCE OF THE BRAIW ON THE ACTION OP THE HEART,

E;£p. 3. On a Exp, 3. The experiment was **epeated on a rabbit. The

rabbit. Action temperature of the room war60«'. The respirations were
of the heart. , - . . „.

made from 30 to 35 m a minute. The actions of the heart

at first were strong and frequent: but at the end of one
hour 40 minutes the pulse had fallen to 24 in a minute.
BIoocL The blood in the arteries was seen of a florid red, and

that in the yeins of a dark colour.

A small opening was made in the abdominal muscles,
through which the thermometer was introduced iiito the
abdomen, and allowed to remain among the Tisoera.
Animal heat. At the end of an hour the heat in the abdomen had fallen
from 100° to 89"^, At the end of an hour and forty mi-
nutes in the same situation the heat had fallen to 85°, and
when the bulb of the thermometer was placed in the thorax
in contact with the lungs the mercury fell to 82°.
Seemingly not It has been a very generally received opinion, that the
de,-^endent on |jg^^ q£ warm blooded animals is dependent on the chemical
chemical ,,,,,,.

changes of the Changes produced on the blood by the air m respiration.
Wood in respi- jf, tjjg ^y^Q j^st experiments the animals cooled tery rapidly,
notwithstanding the blood appeared to undergo the usual
changes in the lungs ; and I was therefore induced to doubt
whether the above mentioned opinion respecting the source
of animal heat is correct. No positive conclusions hovv,
ever could be deduced from these experiments. If animal
heat depends on the changes produced on the blood by
the air in respiration, its being kept up to the natural
standard, or otherwise, must depend on the quantity of
air inspired, and on the quantity of blood passing through
the lungs in a given space of time: in other words, it must
be in proportion to the fulness and frequency of the pulse,
and the fulness and frequency of the inspirations. Ifc
therefore became necessary to pay particular attention ta
these circumstances.
Exp« 4. On a Exp. 4. The experiment was repeated on a dog of a small
small dog. gj^^^ whose pulse was from 130 to 140 in a minute, and
whose respirations, as far as I could judge, were perform^,
ed from 30 to 35 times in a minute.

The temperature of the room was 63^. The heat in the
rectum of the animal at the commencement of the experi.

ment

INFLUENCE OF THE BHAIN ON THE ACTION OF THE HEART; 363-

ment was 99^, The artificial inspirations were made to
correspond as nearly as possible to the natural inspiralions
both in fulness and frequency.

At 20 minutes from the time of the dog being pithed,
the heart acted 140 times in a minute with as much strength v,
and regularity as before : the heat in the rectum had fallen
to m\.

At 40 minutes the pulse was still 140 in a minute : the
heat in the rectum 921.

At 55 minutes the pulse was 112, and the heat in the
rectum 90*.

At one hour and 10 minutes the pulse beat ninety in «
minute, and the heat in the rectum was 88°.

At one hour and 25 minutes the pulse had sunk to 30,
An4 the heat in the rectum was 85*=*. The bulb of the
thermometer being placed in the bag of the pericardium,
the mercury stood at 85®, but among the viscera of the
abdomen it rose to 87|.

During the experiment there were frequent and violent
contractions of the voluntary muscles, and an hour after
the experiment was begun, there was an evacuation of
faeces.

Exp. 5. The experiment was repeated on a rabbit, whose Exp. 5. On a
respirations, as far as I could judge, were from 30 to 40 '^*^^^''
jn a minute, and whose pulse varied from 130 to 140 in a
minute. The temperature of the room was 57^. The
heat in the rectum, at the commencement of the experi-
jnent, was 101 J. The artificial respirations were made to
T€8emble the natural respirations as much as possible, both
in fulness and frequency.

At 15 minutes from the time of the spinal marrow being
iiivid(td, the heat in the rectum had fallen to 98^^.

At the end of half an hour the heart was felt through
the ribs, acting strongly 140 times in a minute.

At 45 minutes the pulse was still 140; the heat in the
rectum was 94**.

At the end of an hour the pulse continued 140 in a mi.
tiute; the heat in the rectum was 92®; among the viscera
of the abdomen 94"* ; in the thorax, between the lungs and
pericardium, 92®.

During

364

Exp. 6. On a

Urge rabbit.

Comparative
experiment on
a smaller.

INFLUENCE OP THE BRAIN ON THE ACTION OF THE HEART.

During the experiment, the blood in the femoral artery
"was seen to be of a bright florid colour, and that in the
femoral vein of a dark colour, as usual.

The rabbit voided urine at the commencement of the
experiment; at the end of the experiment no urine was
found in the bladder.

Exp. 6. I procured two rabbits of the same colour, but
one of them was about one fifth smaller than the other. I
divided the spinal marrow of the larger rabbit between
the occiput and atlas. Having secured the vessels in the
neck, and removed the head, I kept up the circulation by
means of artificial respiration as in the former experiments.
The respirafions were made as nearly as possible similar to
natural respirations.

In 23 minutes after the spinal marrow was divided, the
pulse was strong, and 130 in a minute: the ball of the ther-
mometer being placed among the^ viscera of the abdomen,
the mercury stood at 96^.

At 34 minutes the pulse was 120 in a minute: the beat
in the abdomen was 95'^,

At the end of an hour the pulse could not be felt, but
on opening the thorax the heart was found acting, but
slowly and feebly. The heat in the abdomen was 91**; aud
between the lobes of the right lung 88**.

During the experiment, the blood in the arteries and
veins was seen to have its usual colour.

In this therefore, as in the preceding experiments, the
heat of the animal sunk rapidly, notwithstanding the con-
tinuance of the respiration. In order to ascertain whether
any beat at all was generated by this process, I made the
following comparative experiment. The temperature of
the room being the same, I killed the smaller rabbit by di-
Tiding the spinal marrow between the occiput and atlas. Jn
consequence of the difference of size, cceteris paribus y the
heat in this rabbit ought to diminish more rapidly than in
the other; and I therefore examined its temperature at the
end of 52 minutes, considering that this would be at least
equivalent to examining that of the larger rabbit at the end
of an hour. At 52 minutes from the time of the smaller
rabbit being killed, the heat among the Tiscera of the ab-
domen

JLNrLUENCS OF THE BRAIK ON TH£ ACTIOK OF THE HEART. $65

domen was 92^, and between the lobes of the right lung it
was Ol**. From this experiment, therefore, it appeared, No heat gene,
not only that no heat was generated in the rabbit, in which g^iai fespira^
the circulation was maintained by artificial respiration, buttion.
that it even cooled more rapidly than the dead rabbit.

At the suggestion of professor Dary, who took an in-
terest in the inquiry, I repeated the foregoing experiment
OR two animals, taking pains to procure them more nearly
of the same size and colour.

Exp. 7. I procured two large full grown rabbits of the Exp. 7. Two
lame colour, and so nearly equal in size, that no difference ^^qj^uj^e!^^
could be detected by the eye. one artificial

The temperature of the room was 57°, and the heat in ^pf J^^he ^"^^^
the rectum of each rabbit previous to the experiment other not.
was 100|.

I divided the spinal marrow in one of them, produced
artificial respiration, and removed the head after having
•ecured the vessels in the neck. The artificial respirations
were made about 35 times in a minute.

During the first hour, the heart contracted 144 times in a
minute.

At the end of an hour ayd a quarter the pulse had fallen
to 136 in a minute, and it continued the same at the end of
an hour and a half. At the end of an hour and forty mi*
nutes the pulse had fallen to 90® in a minute, and the arti.
ficial respiration was not continued after this period.

Half an hour after the spinal marrow was divided, the
heat in the rectum had fallen to 97°.

At 45 minutes the heat was 95f .

At the end of an hour the heat in the rectum was 94».

At an hour and a quarter it was 92°.

At an hour and a half it was 91^.

At an hour and forty minutes, the heat in the rectum was
90i, and in the thorax, within the bag of the pericardium,
the heat was 87f .

The temperature of the room being the same, the second
rabbit was killed by dividing the spinal marrow, and the
temperature was examined at corresponding periods.

Half an hour after the rabbit was killed, the heat in ths
rectum was 99^.

At

366

INFLUENCE OF THE BRAIJf ON THE ACTION OP THE HEART,

At 45 minutes it had fallen to 68°.

At the end of an hour the heat in the rectum was 96|.

At an hour and a quarter it was 95®.

At an hour and a half it was 94^.

At an hour and forty minutes the heat in the rectum waa
93°, and in the bag of the pericardium 90^.

The following table will shew the comparative tempera-
ture of the two animals at corresponding periods.

Table of their

comparative

temperatures.

Time.

Before the 7

experiment. 5

SOmin.aft.

45

60

75

90

100

Rabbit with artificial
respiration.

Therm, in
the Rectum.

100|
97
95|
94
92
91
904

Therm, in the
Pericardium.

871

Dead Rabbit.

Therm, in
the Rectum

lOOi
99
98
96i
95
94
93

Therm, in the
Pericardium.

901

The production In this experiment, the thorax, even in the dead animal,
of animal heat cQQig^ jPQre rapidly than the abdomen. This is to be ex-
dep'?nd"on re- plained by the diiference in the bulk of these two parts.
spiration. fhe rabbit in which the circufation was maintained by

artificial respiration cooled more rapidly than the dead
rabbit : but the diiference was more perceptible in the thorax
than in the rectum. This is what might be expected, if the
production of animal heat does not depend on respiration ;
since the cold air, by which the lungs were inflated, must
necessarily have abstracted a certain quantity of heat, par-
ticularly as its influence was communicated to all parts of
the body, in consequence of the continuance of respi-
ration.
Objection. It was suggested that some animal heat might have been

generated, though so small in quantity as not to counter-
balance the cooling powers of the air thrown into the lungs.
It is difficult, or impossible, to ascertain with perfect ac-
curacy, what effect cold air thrown into the lungs would

have

INFLUENCE O* THE BRAIN ON THE ACTION OP THE HEART.

36T

I killed '""?"»:=-

move this*

have on the temperature of an animal under the circum-
stances of the last experiment, independently of any che-
mical action on the blood : since, if no chemical changes
were produced, the circulation could not be maintained,
and if the circulation ceased, the cooling properties of the
air must be more confined to the thorax, and not com-
municated in an equal degree to the more distant parts. The
following e.'^periment, however, was instituted as likely to
afford a nearer approximation to the truth, than any other
that could be devised.

Exp, 8. I procured two rabbits of the same size and Exp. 8. At
colour: the temperature of the room was 64
one of them by dividing the spinal marrow, and imme-
diately, having made an opening into the left side of the
thorax, I tied a ligature round the base of the heart, so as
to stop the circulation. The wound in the skin was closed
by a suture. An opening was then made into the trachea,
and the apparatus for artificial respiration being fitted into
it, the lungs were inflated, and then allowed to collapse as
in the former experiment, about 36 times in a minute. This
was continued for an hour and a half, and the temperature
was examined at different periods. The temperature of
the room being the same, I killed the second rabbit in the
same manner, and measured the temperature at corres-
ponding periods. The comparative temperature of the two
dead animals, under these circumstances, will be seen in the
following table.

Time.

Before the ex-
periment.
SOmin.aft

45 .

60

75

90

Dead Rabbit whose lungs
were inflated.

Therm, in the
Rectum.

Therm, in
the Thorax

100
97
95|
94
92|
91

86

Dead Rabbit -whose lungs
were not inflated.

Therm, in. the
Rectum.

100
98

94|

93

91j

Therm, in
the Thorax

88|

Tabulated re-
sults.

la

368 INFLUENCE OF THE BRAIIT ON THE ACTION OF THE HEART.

Ko animal heat In this last experiment, as may be seen from the aboTe
SSd^byUJ?'"^ table, the difference in the temperature of the two rabbits,
fpiration. at the end of an hour and a half in the rectum, was half a

degree, and in the thorax two degrees and a half; whereas,
Ip the preceding experiment, at the end of an hour and
forty minutes, the difference in the rectum was 2^ degrees,
and in the thorax 3 degrees. It appears, therefore, that
the rabbit in which the circulation was maintained by arti-
ficial respiration cooled more rapidly on the whole, than
<he rabbit whose lungs were inflated in the same manner
after the circulation had ceased. This is what might be
expected if no heat was produced by the chemical action of
the air on the blood ; since in the last case the cold air was
always applied to the same surface, but in the former it
-was applied always to fresh portions of blood, by which
its cooling powers were communicated to the more distant
parts of the body.

In the course of the experiments which I have related, I
was much indebted to several members of the Society for
promoting the Knowledge of Animal Chemistry, for many
important suggestions, which have assisted me in prosecut-
ing the inquiry. Mr. Home, at my request, was present
at the seventh experiment. Dr. E. N. Bancroft was pre-
sent ^t, and assisted me in the second experiment : and Mr.
William Brande lent me his assistance in the greater part of
those which were made. I have been farther assisted in
making the experiments by Mr. Broughton, surgeon of the
Dorsetshire regiment of militia, and Mr. Richard Rawlins,
and Mr Robert Gatcombe, students in surgery.
Kany other ex- I have selected the above from a great number of similar

penments gave experiments, which it would be needless to detail. It is
nmilar results. L . . , , , , ,

sufficient to state, that the general results were always the

same; and that, whether the pulse was frequent or slow,
full, or small, or whether the respirations were frequent or
otherwise, there was no perceptible difference in the cool-
ing of the animal.
General con- From the whole we may deduce the following con-
clusions, elusions:

1. The influence of the brain is not directly necessary to
the action of the heart.

2.When

INFLUENCE OF THE BRAIN ON TKE ACTION OP THE HEART. 360

2. When the brain is injured or removed, the action of
the heart ceases, only because respiration is under its in-
fluence, and if under these circumstances respiration is ar.
ficially produced, the circulation will still continue.

3. When the influence of the brain is cut off, the se-
cretion of urine appears to cease, and no heat is gene-
rated; notwithstanding the functions of respiration and
the circulation of the blood continue to be performed, and
the usual changes in the appearance of the blood are pro-
duced in the lungs.

4. When the air respired is colder than the natural tem-
perature of the animal, the effect of respiration is not to
generate, but to diminish animal heat.

AddUton to the Croonian Lecture for the Year 1810.
(P. 207.)

In the experiments above detailed, where the circulation Artificial re-
was maintained by means of artificial respiration after the ^P'^J^'^!J^^[^*
head was removed, 1 observed that the blood, in its pas- changes on the«
s.age through the lungs, was altered from a dark to a^^^°°^^J^"^
scarlet colour; and h(;nce I was ted to conclude, that the
action of the air produced in it changes analogous to those,
ivhich occur under ordinary circumstances. I have lately, '

with i\\e assistance of my friend Mr. W. Brande, made the
following experiment, which appears to confirm the truth
of this conclusion.

Ati elastic gum bottle, having a tube and stop-cock con- Experiment to
nected with it, was filled with about a pint of oxigen gas. ^^^°^^ '^"^*
The spinal marrow was divided in the neck of a young
rabbit, and, the blood vessels having been secured, the head
was removed, and the circulation was maintained by in- \

flating the lungs with atmosphelic air for five minutes, at
the end of w hich time the tube of the gum bottle was in-
serted into the trachea, and carefully secured by a ligature,-
so that no air might escape. By making pressure on the
gum bottle, the gas was made to pass and repass into and
from the lungs about thirty times in a minute. At first,
the heart acted one hundred and twenty times in a minute,
with regularity and strength ; tho thermometer, in the rec- '

turn, rose to 100^. At the end of an hour, the heart
acted as frequently as before, but more feebly; the blood

Vol, XXIX,— SupPLEME^'T. D b in

370 mSOXIDATIOI^ or IROW by HIDROGEV OAf.

in the arteries was very little more florid than that in the
reins; the thermometer in the rectum had fallen to 93®.
The gum bottle was then reraoTcd. On causing a stream of
the gas, which it contained, to pass through lime water,
the presence of carbonic acid was indicated by the liquid
being instantly rendered turbid. The proportion of car-
bonic acid was not accurately determined ; but it appeared
to form about one half of the quantity of gas in the bottle.

B. C. BRODIE.

IX.

Notes hy Mr. J; H. Hassenfratz on the Disoxidation of
Oxide of Iron by Hidrogen Gas*,

Disoxidation of IJeSIROUS of repeating the experiment of Messrs.
gen gas. Priestley, Chaussier^ and Amadeus Berth ollet, on the dis-

oxidation of iron by hidrogen gas, I last year employed
Mr. Charbaut, then a pupil of the School of Mining, to
make the experiment in my presence. He proceeded in two
ways; in one the iron was disoxidated by hidrogen, in the
other by oil and charcoal. In the latter experiment the
metal was fused by increasing the temperature, so as to
obtain a button of iron.
More weight On comparing these two modes, I was astonished to And,
iXSfonb'y^a *^** *^® diminution of weight of the oxidule of iron by hi-
and charcoal, drogen was always greater than that effected by oil and
charcoal. The perplexity into which I was thrown by these
The experi- results induced me to repeat the experiment anew. Ac-
t pea e . j,Q,.^jjjg]y ^^j^jg yg^^ J employed at the Practical School of
Mining the pupil Desroches, of whose sagacity and pre-
cision I was previously satisfied, to decompose by the action
of hidrogen gas oxidules of iron from the valley of Aoste,
and specimens of oligist iroa from Elba, while other pupils
assayed the same minerals before me in the dry way. Tho
results obtained agreed precisely with those of last year;

* Ann. dc ChJm. vol, Ixxiii, p, HI,

Finally

iitSoitiiil'tbk OP IROJ^ BY rilDkOGEI* (JAi. 3tl

Finally, at my departure from Moutiers, I reqbestetl the
pupil Desroches to make fresh experiments oti the decom-
position of the oxidule of iron of Cogne, and oligist Iroa
of Elba. The official statement of these experiments, cer-
iified hy engineer Leboullenger, I shall proceed to lay be-
fore thii publifc.

sExperitnents on the Disoxidation of Oxide and Oxidule
of Iron*

li has befcn said, thit all metals are capable of being dis- Disoxidation ai
oxidated by heat, and that the temperature required fo^ metals by heat.
their reduction is much higher than that of their oxidation.
It is easy to conceire, that, if the tefldency to take the
aeriform state be less powerful than the attraction of the
oxigen by the metal, the oxigcn will be solidified, and an
oxide formed: but if the elasticity be superiot to the at-
traction, no combination, or oxidation, will take place.
This occurs in the manufacture of minium: too strong a
fire produces massicot, and sometimes reduces the oxide en-
tirely. It is observable too, that, beyond a certain tetn- Oxidation by
perature, the time Required for oxidation is in the inyerse^^^**
ratio of the heat. This I had an opportuity of observing
in the oxidation of iron by heat last year. Having taken
some pure filings of good iron, and exposed them to a
graduated heat, I obtained in a very little time an addition
of 32 per cent : I increased the heat and the current of
air, but it was a long while before I gained 40 per cent:
and it was not without a great deal of trouble, and a ver^
long time, that t obtained the known result of 45 per cent,
which I could not exceed.

But is heat alone capable of reducing all metals ? This Are all metalj
question is already decided with respect to some, which [^^"J^,^^^® ^y
have but a feeble attraction for oxigen. As to those which
retain it forcibly, it may be, that the heat requisite for their
disoxidation is superior, or at least equal to that necessary
for their fusion ; and then it would be impossible to separate
ihe gas from the riietal.

But if a powerful disoxidizer be employed ifi conjunction
with caloric, so great a heat will not be required to reduce
the metal: thl3 no doubt induced tlt^ ;^oaDger Mr. Ber«
^"^"''"i Bb2 . thollet

372 DISOXIDATION OF IRON RY IIIDROGEN CAS.

. thollet to employ hidrogen gas in his experiments, which
I repeated as follows.
Two specimens I took 5 gram. [77*23 grs.] of oxidulatcd iron of Cogne,

of native oxide ^^ J ^ gjjjjjj^j. quantity of oligist iron of Klba, and placed
of iron exposed ^ j o 7 r

to the action of them in a semicircular tube with two compartments, intend.
hidrogen gas. ^^ g^^h to hold one of the oxides. This tube, furnished
-with a long stem curved at one end, was placed in a gun-
barrel open at both ends, previously cleaned, and coated
externally with loam, to preserve it from oxidation. At
the curved end of the stem, which answered to one of the
ends of the gunbarrel, a curved tube was luted, terminat-
ing underwater, and intended to afford a passage to the super-
fluous hidrogen gas and the vapours of the apparatus, which
were collected in bottles filled with water, and resting on a
perforated test, underneath which the tube opened. The
gunbarrel was placed 4 inches from the grate in a furnace,
the opening of which was 8 in. [85 Eng.] wide, and 12
'[12'8] high from the grate, which rested immediately on
the nozzle of a pair of forge bellows. To the other end of
the guijbarrel was fitted a tube, curved likewise, commu-
nicating with a cock placed under a jar completely im-
mersed in a tub of water, the pressure of which was in-
tended to force out the hidrogen gas, with which the jar
was kept constantly filled.

All the parts of the apparatus being securely fixed and
luted, it was found to be air tight, by passing a measured
portion of air from the jar into the receivers at the other
extremity.

Hidrogen gas was then prepared from iron filings and
diluted sulphuric acid; the furnace was filled with charcoal;
the fire was kindled, and blown gently. When the gun-
barrel was redhot, which might easily be seen through the
glass tubes at its two extremities, the cock was closed, and
the jar filled with hidrogen gas. This gas was then passed
through the apparatus, by opening the cock a little. Part
of the gas was absorbed; and the remainder, which was re-
<Jeived in the bottles with theaqueous vapour that condensed
in them, was returned into the jar. In this process the
oxidule and oligist iron at this temperature, presenting to
the gas a porous mass, which it could easily traverse, each

particle

DISOXIDATION OF IRON BY HIDROGEN GAS. 373

.particle was surrounded with hidrogen, gave up its oxigen^
and formed vapour of water, which was perceived to con-
dense in the curved tube at the extremity of the barrel ;
and. which, at the close of the operation, when the heat
was excessive, traversed all the water in the tube and the
bottles, producing wreaths of white vapour, similar to
those issuing from rockets.

Care was taken to keep in the tub a sufficient quantity
of water to cover the jar; and also such a quantity of gas
in the jar, that the pressure should be always nearly the
same, and the passage of the gas consequently uniform*
The fire was gradually increased ; but absorption still tak-
ing place, it was stopped when it appeared to be at a maxi-
mum. I then thought I observed, that the fire was not
stronger than might have been produced in a common fur-
nace, simply supplied with the current of air passing
through the ash. hole, so that the bellows were useless. This
however I mention only as a conjecture, more decisive
proofs being necessary to ascertain it.

We were employed in the fatiguing operations of sup-
plying fuel, filling the jar with hidrogen, emptying under
it the bottles containing the hidrogen that had passed through
the apparatus, preparing others to receive that which was
constantly issuing from it, and keeping up the level of the
water in the two tubs, for four hours aud a half. At the
expiration of this time the iron oxides having absorbed the
eight bottles of hidrogen gas that had been prepared, it
was necessary to put an end to the experiment: and for ray
own satisfaction, I dilated the end of the gunbarrel that
contained the plate iron stem of the tube, and the curved
end of this stem enabled me to draw out the tube with ai)
iron wire. I weighed the iron immediately; that of Cogne Their weight
weighed 4*19 gr. [64-72 grs.] ; that of Elba, 3-77 gr- ^erTment^''"
[58-23 grs.] penmen ,

The oxidule of Cogne had become altogether stony, and which was pep*
of a yellowish gray. Many pieces of the oligist iron had pfjjg^^^*^^"**
lost their metallic lustre, having turned yellowish, and ac-
quired a duller lustre like that of silver: but I was notcer-
tain, that this iron was reduced, since no superfluous hi-r
^rogen gas had passed over.

3 " This

374 DI^OXIDATION OF IRON BY pIDROGEN GAS.

and therefore This induced me to continue the experiment. The ap«

repeated, paratus was fitted up again as before; aqd, after I had

^ made a considerable quantity of hidrogen gas, and taken

the precautions aboTementioned, the fire was kindled, and

gas was passed oyer, till no sensible absorption took place.

All the fuel remaining in the furnace was then consumed^

by continuing the action of the bellows; and during this

combustion gas was still passed over, that no water might

introduce itself into the guubarrel during its cooling, which

"was thus effected Tery gradually. The jar was cooled full

of gas, and the apparatus taken to pieces as before.

Weights. Th^^oxidule of Cogne now weighed 3-69 gr. [56 QQgrg.]

and the oligist iron of Elba 3-32 gr. [51-28 grs.]
State of the The oxidulated iron of Cogne had altogether lost its

°^ ' metallic lustre : its yellowish aspect exhibited spots separ-
able from the yellowish gray ground, which, examined
with a lens, exhibited a sort of metallic arborizations of the
colour of cast iron. On hammering it acquired lustre,
and flattened, but at length broke (owing, no doubt, to
the impurities of the ore). Its fracture was then very
brilliant, and resembling that of iron,
and of that of The iron of Elba had likewise lost its metallic lustre,
^^^* bnt had assumed a duller, resembling that of silver. Some

jparts had the appearance of a sponge, coloured super-
ficially with a fugitive tint, varying from yellow to that of
coarse Prussian blue, and thence to violet. All its species
were malleable, and were reduced thinner under the ham-
mer than the iron of Cogne before they broke. After the
experiment the specimens were analysed, to determine ex-
g,ctly the quantity of iron they contained.
The iron of The 3*69 gram. [56 '99 grs.] of iron of Cogne were

Cogne ana- treated with nitromuriatic acid. A large quantity of nitrous
acid was evolved in red fumes, which proved the great dis-
oi[ida,tion of the oxidule. That nothing might be lost, it
was not levigated; which did not prevent the action from
being brisk, and completed in a few hours, even without
beating. This was necessarily the case; for, the iron hay-
ing been rendered very porous by the process of disoxida-
tion, every particle of the metal was separated, as it were
from the rest, and from the earthy particles^ so that the

aci^

DISOXIDATION OP IRON BY HIDROGEN GAS. §75

acid oould act on them with facility. Having evaporated The iron of
to dryness, water was added, and a little muriatic acid, to jysfd ^ *°*"
fake up the oxide of iron separated by drying. A whitish
granular precipitate was obtained; which, collected on a
filter, washed and calcined, became very white, and weigh-
ed 0*36 of a gram. [^5 56 grs.] This was silex.

The solution, of a fine orange yellow colour, was sa«
turated by ammonia; only taking care to leave a slight ex-
cess of acid, to hold in solution all the earths, that might
have fallen down with the oxide of iron. This oxide was
collected on a filter ; and the liquor assayed by carbonate
and oxalate of ammonia to detect the presence of alumine
and lime. No precipitate being thrown down, the liquor
Tvas evaporated to dryness ; and the muriates, oxalates, and
carbonates of ammonia and magnesia (for, if there were
any earth present, it could only be magnesia) were after-
ward calcined. The ammoniacal salts were volatilized; and
a substance was left (it was an oxalate), which, having
been again calcined on a porcelain test, became white, and
weighed 0*31 of a gr. [4-79 grs.] It was magnesia.

As the oxide of iron remaining on the filter might still
contain other metals and earths, it was treated by acetic
acid, and heated to dryness. Water was then added, and
it was heated to dryness again. Lastly, after having added
more water, cleaned the capsule, and heated a little; the
solution was filtered, evaporated to dryness, and the re-
«iduum calcined on a porcelain test. The whole was vola-*
tilized, except a blackish, alkaline substance, incapable of
being weighed, which was presumed to be lime (proceeding
from the filtres) contaminated by the carbon of the decom-
posed acetic acid.

The iron left on the filtre was treated with muriatic acid,
because it was suspected to contain silex ; for the nitro-
muriatic acid might have dissolved a portion of this earth
in its state of disintegration, and the ammonia would have
precipitated the silex with the iron. This in fact was the
case: for, after having filtered the solution of iron, there
was a residuum, which, when washed and calcined, be-
came very white, and weighed 0*2 of a gram. [3*09 grs.] ;
apd this was sHqx.

The

375 DISOXIDATION or IRON BY HIDROGEH. GAS.'

The iron was precipitated by ammonia, which was boiled
on it repeatedly to remove the acid; and, after calcination
in the open air, 4*08 gr, [63*02 grs.] of- fine red oxide of
iron .were oBtained.

Resulte. Thus the oxidulated iron of Cogne yielded

Red oxide of iron - 4-07*^ grammes = 62-86 grains
Silex - - - 0-56 = 8-65

Magnesia - - '0'31 =4-79

Accordingly it contained 0*87 of a gr. [13*44 grs.] of earth :
and consequently of the 5 gr. [77*23 grs.] employed only
4*13 gr. [63*75 grs.] vyere oxidule. Now in the experi-
ment of the disoxidation the 5 gr. [77*23 grs.] were re-
duced to 3*69 [56-99 grs.] : 4*13 gr. [63*75 grs.] of oxidule
therefore contained 1*31 gr.- [20*23 grs.] of oxigen (lost in
the experiment;) and consequently the oxidulated iron of
Cogne is at '141° per cent, or 31*72 per cent.

Results of the In like manner the oligist iron of the isle of Elba

^^^' yie"Je<l by analpis

Red oxide of iron - 4*4 grammes = 67*96 grains
Silex - - . 0*25 = 3*86.

Thus, as. there were 0*25 of a gr. [3*86 grs.] of earth,
there were only 4*75 gr. [73*37 grs.] of oxide in the sub-
stance employed : and, as the 5 gr. [77*23 grs.] were re-
duced in the experiment to 3*32 gr. [51*28 grs.], they had
lost 1*68 gr. [25*95 grs.]; consequently there were 1*68 gr.
[25*95 grs.] of oxigen to 4*75 gr. [73*37 grs.] of oxide;
The oligist iron of the isle of Elba therefore has *||-|° per
cent of oxigen, or 35*37 per cent nearly.
' If we may be allowed to depend on these results, we

may conclude, that the oxidulated iron of Cogne contains
32 of oxigen in 100 of the oxidule; and that the oligist
iron of Elba contains 35 of oxigen in 100 of oxide.

Other Results.
Results from It has been seen, that there were 4*13 gr. [63-75 grs.]

the iron of ^^ oxidule in the iron of Cogne, and that this iron was

Cogne, °

oxidized in the proportion of 31*72 per cent. It has ap-
peared too, that the 3*69 gr. [56*99 grs.] of iron of Cogne

* Just above it is said 4*08 gram. C.

obtained

DISOXIDATldN* OF IRON BY HIDROGEif GAS.' 377

obtained by disoxidation contained 0*87 [13*44 grs,] of
earth; consequently there were 3*69 — 0*87 = 2*82 gr.'
[43-56 grs.] of pure iron.- In the analysis of this iron
4*07 gr. [62-86^rs.] of red oxide were obtained: the red
oxide therefore contained 4-07— 2*82= 1-25 gr. [19-31 grs.]
of oxigen; and consequently was at *|f|° per cent, or 44
per cent and upward, (allowing for any trifling errour).

As to the iron of Elba, we find hy calculation, that the'and that of
red oxide obtained was at 43 per cent and upward, allowing
likewise for any trifling errour ; and if we take the mean
of the two results, admitting decimals and allowing for any
little errour, we shall findj^that the red oxide is at 44 per
cent.

In some troublesome experiments, which I shall not de- Hidrogen ob-

scribe, I was employed to obtain hidrogen by the decom- f^^^^^ ^'y P^^*
. . „ V. ^ ■ -r -, /. ^ng water over

position of water, r or this purpose 1 took some very fine iron wire,

iron wire, which I weighed and introduced into a gunbarrel,
adapted to this a retort filled with water, and proceeded in
the usual way. After the process I had a wire extremely state of tht
increased in size, consisting of an assemblage of octaedral *^°"*
crystals so small as to be visible only by a lens, and form-
ing a fragile wire oxided in all parts. I weighed it, and as
there were still some parts that had been less heated, and
not perfectly oxided, I pulverised the oxidule, subtracted
the iron thus separated, and on calculation found I had an
pxidule of 32 per cent and upward.

DESROCHES.

This is to certify, that these experiments were made at
the laboratory of the School of Mines in the month of
August, 1809,

LE BOULLENGER.

Observations by Mr, IIassenfratz.
It follows from the experiments of Mr. Desroches, that Observations bj
the oxidule of Cogne lost 0*317 of oxigen, which amounts ^^^^^j^ ^^^^'
to 46 parts to 100 of iron; and that the 'oligist iron of
Elba lost 0'3537; which would make more than 54 io 100
of iron.

Th«

578 DISOXIDATIOIf or IRON BY HIDROQEN GAS.

The oxidule of Cogne, treated with charcoal, in oti<5
cTperimeot yielded from 5 gr. [77*23 grs.) a button con-
taining 3-42 gr. [52*82 grs.] of iron, and 0*66 of a gr.
[10 19 grs.] of scoriae, which would make the loss about
27 to 100 of iron; and in another experiment the 5 gr.
yielded a button containing 3*38 gr, [52*21 grs.] of iron,
and 0-78 [12*05 grs.] of scoriae, making the loss 25 to 100
of iron. We will take the highest term, 27.

The oligist iron of Elba yielded from 5 gram, a button
of iron weighing 3.6 [55*6 grs.] and 0*1 [1-54 gr.] of scoriae;
which would make the loss 30 to 100 of iron.
Iflfore loss in Thus the difference of loss in the two modes of reducing

thertxJuction f^Q oxide of iron would be for the oxidule of iron of

by hidrogen

than in that by Cogne 46 by hidrogen, and 27 by charcoal ; and for the

charcoal. oligist iron of Elba 54 by hidrogen and 30 by charcoal.

Possible causes With regard to the causes, that may produce this dif-
ofthediffer- ference, we may dislinguish three: 1, the charcoal, that
combines with the iron, when the metal is fused with this
combustible: 2, the oxigen, that may remain combined
with the iron in the metallic button obtained : 3, the action
of the hidrogen on the iron, the gas dissolving and carry-
ing off some of the metal.
Addition to the Desirous of knowing what might be the influence of each
iron by carbon, ^^ these causes, I fused in a crucible lined with charcoal
5 gr. of iron wire preTiously soaked in oil, and obtained
a button weighing 5*13. Hence it follows, that somewhat
less than 0*03 of carbon was combined with it.
and by carbon I afterward dissolved 5 gr. of iron in nitric acid, in order
and oxigen. ^^ oxidate the metal to a maximum ; moistened the oxide
with oil; placed it in a crucible lined with charcoal to fuse
it; and obtained a button weighing 5*2 : consequently 0*04
of carbon and oxigen had combined with the iron.

Supposing, that 0*04 of carbon and oxigen remained in
the buttons obtained from the oxidule of Cogne and the
oligist iron of Elba, it would follow, that the oxidule of
Cogne had lost near 32 per cent of oxigen, and the iron
of Elba near 36.
DifFerence be- These two results agree in placing the oxidule of Cogne
tween th« two ^^ ^^^ ^.^^j^ ^^ black oxides obtained by the decomposition
of water o^er iron 3 for this proportion of 32 Is nearly

what

DISOXIDATION OP IRON BY HIpROGEN GAS. 3^

xvhat I have deduced from the experiments of several able
chemists on the composition and decomposition of oxidules
of iron. It is also the same as Mr. Desroches has deduced
from the experiments he made this year at Moutiers.

It follows too from these experiments, that the oligist
iron is more oxided than the oxidule, as the learned Mr.
Haiiy had concluded from the colour of these two ores
when powdered.

But when we have taken account of the carbon and Loss in the re-
oxigen combined in the metallic button obtained from the^^JJJLJJJ"j^J^^jJ^
disoxidation of oxides of iron by charcoal, it appears, that accounted ioi.
the loss they undergo in their reduction is still less than that
which occurs when they are disoxided by hidrogen ; since in
the latter case the oxidule of Cogne lost 46 to 100 of iron,
while it lost but 32 in the reduction by charcoal; and the
iron of Elba lost 54 with hidrogen, and only 36 with char-
coal.

Is this difference ascribable to the solvent action of hi- Iron apparently
drogen ? Some observations seem to warrant this conclusion. cardeToff by
1, When the hidrogen gas obtained by the decomposition of the hidrogen,
water passed over iron, or by dissolving this metal in acids,
or otherwise, is preserved in jars over water, the interioF
of the jars sometimes becomes coated with a slight stratum
of oxide of iron. 2, At the end of the account of his ex-
periments Mr. Desroches had added the following note.
*' A great deal of ferruginous hidrogen gas was evolved, as
I found by its smell ; so that probably some iron was lost
in the passage of the hidrogen gas through it."

I do not think however, as Mr. Desroches observes, that This deserves
we should hastily conclude hidrogen to have a solvent ac- "^^^'"^y*
tion on iron from his experiments alone. They should be
repeated and varied in several waysy before we decide on
a fact of such importance. It is sufficient for me at pre-
sent to have called the attention of chemists to a result, ihat
is worthy their consideration.

X. Determination

380 COMPOSITION OP AMALGAM OF AMMONIA.

Determination of the Quantity of Hidrogen and of Am^
monia contained in the Amalgam of Ammonia : by Messrs*
Gay-Lussac and Thenard *.

Quantity of hi- W E took 3*069 gr. r47-4Q3 firrs-l of mercury, placed
drogen contain- ,, . ,, , * , . , . ,

ed in amalgam ^"®"^ *" 3, small cupel of sal ammoniac at the negative pole,

of ammonia, and, when their, bulk was about quintupled, threw them
into a conical glass filled with water, in which was pre-
viously placed a small jar also filled. The bubbles of air,
that might have been adherent to the button of amalgam,
were at first suffered to escape, by keeping the jar close to
the sides of the glass; after which the jar was raised, so as
to let the button fall to the bottom, and all the hidrogen
gas arising from it was collected gradually in the upper
part of the jar. Six buttons of amalgam, each made with
a similar quantity of mercury, and treated in this manner
successively, produced such a quantity of hidrogen, that
the mercury had absorbed 3*47 times its bulk of this gas in
passing to the state of soft amalgam. To avoid every
source of errour, the bulk of the mercury employed and
of the hidrogen collected was measured in the same tube,
which was accurately graduated.

A second experiment, made also with six buttons cf soft

amalgam, having afforded results scarcely differing from

the preceding, they may be considered as exact, or at

least as approaching very nearly to the truth. It may

happen however, that, on a repetition of these experi,

ments, other numbers than ours maybe found; and this

must necessarily be the case, if the amalgam were not

made so as to obtain it soft, or so that the mercury enter^

ing into it should have its bulk at least quintupled.

Quantity of am- ^^ imagined at first, that by amalgamating a given quantity

monia contain- of mercury and deducting the known weight of the mercury

of ammonfa! and the hidrogen it contained, we should find exactly thequan-

tity of ammonia entering into the amalgam. But we sooii

* Annal. de Chim. vol. Ixxiii, p. 209. Extracted from a paper
read to the Institute, September, 1809.

found

COMPOSITION OF AMALGAM QF AMMONIA. 581

found, that this mode of analysis was Tery inaccurate : 1st,
because the amalgam is half destroyed before it is well dried :
2dly, because this amalgam displaces a volume of air, of
which it is difficult to take account: 3Jly, and lastly, be-
cause, on introducing it into the phial, the hidrogen and
ammoniacal gas evolved take the place of a quantity of
air, which cannot be estimated, and must necessarily occa-
sion great errours in the results. Hence the weights of all
differed from one another. One gave us on 3*069 gr. of
mercury an augmentation of 0*002; another, an increase
of 0003 ; a third, of 0-0045 ; and a fourth, of 0-001 only.
It is even possible, that a loss of weight might appear,
since the air of the phial is replaced by hidrogen and am-
moniacal gas. Such no doubt were the causes of Mr. Davy's
mistake, when he found that mercury, in forming an
amalgam, was increased only a twelve-thousand"th of its
weight.

Impelled by these reasons to reject thi$ mode of analysis, Mode of ana-
we employed the following, which we consider as very 'ysis employed,
exact. Knowing the quantity of hidrogen contained in the
ammoniacal amalgam ; and not doubting, that the hidrogen
and ammonia were in a uniform proportion to each other
in this amalgam, we had recourse to this proportion, to de-
termine the whole quantity of the ammonia it contained^
For this purpose we converted into amalgam 3*069 gr.
[47*403 grs.] of mercury; after the amalgam was well
dried with blotting paper, we introduced it immediately into
a small jar very dry, and a quarter iilled with mercury;
and immediately too clapping a finger 'on the mouth of the
jar, we shook the whole together for a few minutes. In
this way the portion of amalgam that still subsisted was de-
composed, the hidrogen and ammonia it contained return-
ing to the state of gas; for the moment the little jar was
immersed in mercury and unstopped, the mercury was seen
to sink. Three other similar experiments were made, in
order to obtain more decisive results; and after each ex-
periment the gasses were passed into one and the same very
dry tube filled with mercury. When they were thus all
collected in the tube, the quantity of ammonia they con-
tained was determined by agitating them with water. Then,

to

36S DECOMPOSITION OF CERTAIN SUBSTAls'CEJl BY ilEAT.

to know exactly the quantity of hidrogetl prfescnt, whlcli,
in this residuum, was mingled with a great deal of comriion
air, it was burnt in Volta's eudiometer, with kn atdditioft
of hidrogen and oxigen iti kndwrt quantities, id Order to
render the combustion complete and more easy.
Results. Thus we fOund, that in these gasses the ammotiia was to

the hidrogen as 28 to 23. But as we knew, that thd ifter-
cury absorbed 3*47 titries its bulk of hidrogen in ]()assing
to the state of soft amalgam, it follows, that, in acquiring
this state, it absorbs at the same titil* 4-22 tiifies iH bulk
of ainraOulacal gas : and cotisequ eiitly the mferctiry, !tt psii$»
Ing to thfe stdte Of amalgam, is ihci-feased in \teight about
0-0007; while from the experiments of Mr. Davy it id
increased only a t\^el?fe-thOusandth. ,Our increase toO iS k
minimum; for it is very possible, that a part of the am-
inonia is absorbed in thii course of otir experiment. Though
this increase is very small, it would appear sufficient to
explain the formation of the amalgam, if it be considered,
th^t hidrogen and ammonia are very light substances ; and
that, being retained in this amalgam by a very w,eak affinity,
they are starcely more condensed than in the free state.

ti.

On the Decomposition of some vegetable or animal Subm
stances subjected to the Action of Heat : by Mr. Gay-

LUSSAC*.

5ortesub- V^ ilEN" certain substances belonging to the vegetable

decomposed by 01* animal kingdom, as oxalic acid, indigo, &c., are sub-
heat, partly jected to distillation, part is decomposed, and part is vola-
tilized without alteration. To prove, that this is not owing
to the impurity of these substances, we have only io distil
anew what was volatized, and we shall find as much in pro-
portion decomposed as tbe first time; so that, if the pro-
cess be frequently repeated, we shall obtain a complete de-
composition. These facts, though very remarkable, Iiav6

* Ann. cte C^im. vol. Ixxiv, p. 189. Communicated Co vthe
Society of Aicueil, Novarabfef, 1809'.

not

DECOMPOSITION OP CERTAIN St^BSTANCfiS BY ȣAT. ^3

not sufficiently engaged the attention of chemists: I will
therefore endeavour to explain them from the principles I
have laid down in a paper on the volatilization of sub-
stances, printed in the first volume of the Society of Arcueil.
The question to be solved is this: Why, when certain sub* Why?
stances of the vegetable or animal kind are distilled, is part
decomposed, and part volatilized? Why are they not en-
tirely volatilized, or entirely decomposed ?

The substances, that present to us this kind of altera- Volatilization
tion are volatile, and at the same time capable of being de-^j^^^J*^ oyheat
composed by heat. Farther, a substance cannot be vola-
tilized below the point at which its vapour has a degree of
elasticity sufficient to overcome the weight of the atmos-
phere, unless this vapour can mix with the air, or some or assisted by
other elastic fluid. S^^'

Now if a substance, that is both volatile and capable of Asubstan«e
being decomposed, be subjected to the action of heat, ** JI^fJ^^^T^^^
may happen either that it will be completely volatilized, decomposition,
before it experiences a sufficient degree of heat to decom- ^"^ ^^^ *'''"^*'^^'
pose it; or that it will be decomposed, before its vapour
has acquired a sufficient elasticity, to overcome the pressure
of the atmosphere.

In the first case there is no difficulty: it is that of the First case,
distillation of acetic acid, alcohol, ether, volatile oils, &cw
As to the substances included in the second, as indigo, thesecoad,
oxalic, gallic, and succinic acids, wax, suet, fixed oils, 8cc,
they begin to be decomposed, before they are volatilized :
but, as their decomposition produces gasses, these gasses Oause of a
will cause the volatilization of the part not decomposed, in Pf:*^"*.^ ^**/**
the same manner as the air causes that of water below its
boiling point.

Since the gasses that result from the decomposition of a\»hich maybe
substance are the cause of its volalilization, and withdraw P'^^®"^®^,
it from complete destruction; and as all elastic fluids possess
the same properties in this respect; it is easy completely to
Tolatilize indigo, several vegetable acids, and many other
substances, without their undergoing any alteration. It
is sufficient, to keep their temperature a little below that
at which they are decomposed, and^o cause a current of
some elastic fluid, that has no chemical actioa on diem^ to
pass through them.

These

584 REMARK O-N MR. MOORE'S PAPER ON ROCKET**

These observations will be found, no doubt, capable of
frequent application. It was from not being acquainted
with them, that Mr. Chevreul has given an explanation of
the action of caloric on indigo, which is by no means sa-
tisfactory.

XII.

Remark on Mr. Moore's Paper on the Motion of Rockets.
In a Letter from a Correspondent.

To Mr. NICHOLSON.
SIR,

Remark on Mr, A OUR readers undoubtedly feel much indebted to Mr.

Moore's paper lyjoQi-g for soiTie ingcpious papers upon the motion of
rockets. As the subject is an important and curious one,
it is highly deserving of accurate investigation. On this
account I am desirous of pointing out to Mr. Moore's no-
tice, as early as possible, an errour iqto which he has in-
advertently fallen. In his investigation of the resistance
opposed to a cylinder moving in a fluid, in a direction in-
clined to the axis, he expresses the sine of the angle P T «
(see fig. 2, Plate vii,) in terms of the sines and cosines
of PTQ, andQTw; forgetting that the three angles are
in dffferefit jdanes^ and consequently that the trigonome-
Irical formula, to which he refers, will not apply,

I am, Sir,

Yours, &c.

ZENO.

INDEX

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INDEX.

Acii), oximuriatic, see Ga&
AcitJ, boracic, experiments on its com-
binations with potash and soda, 119
Affinity, cheaiical, referred to elec-
tricity, on the hypothesis of, 12
Agriculture, means of improving, 314
Agricultural instruments, their respec-
tive meHts, 171
Air engine, a new, described, 175-^An-

nother for extracting foul air, 330
Air pump for procuring a perfect va-
cuum, its construction described, 107
Albumen of seeds, its use, 23(>
Algorithm of imaginary quantities, de-
fective, 254
Alkalis, their nature, &c., 35, 38, 59
—How acted upon by oximuriatic
gas and oxigen, 113, 222
Alkaline metalloids, observations and

experiments on, 183
Allan, Mr. on the rocks in the en-
virons of Edinburgh, 151
AUanite, a new mineral from Green-
land, 47
Alum mines of Aubin, 352
Ammonia, amalgam of, its composi-
tion, 60, S80
Analysis of allanite, 47— -Of calomel
and corrosive sublimate, 228— Of
tobacco, 153— Of the belladonna, 153
—Of pure oximuriatic gas, 279—
Of sodalite, 289— Of an ancient bell,
315
Apes, classification of, 239— Two new

species of, ib,
Arago, M. 77, 78
Arbor vitae, description of, 208
Asparagus, gerinination of, 237
Atomic principles of chemistry, re-
view of the theory of, 143
Attraction, considered as an ultimate

property of matter, 18
Aubm, mineralogy of, 352
Azimuths, metiiods of determining,

77

Vol. .XXIX.

B.

Bachelier*s preservative mortar. 155
Baker, Mr. J. his improved implement
for extirpating docks and thistles, 301
Balls, Mr Thomas, his descriptien of

a screw adjusting plough, 298
Balm of Gilead, natural history of, 208
Barberry, flower of the, its motion,

<Src., 213
Barometer, improvements in the scale

of, 105
Barometrical measurements, on Mr.

Hainond's coefficient for, 77
Bean stalks, fibres of, converted into st

substitute for hemp, 278
Bell, an ancient, described, and ana-
lysed, 315
Belladonna, analytical examination of

.153
Berthollttt, M. on the loss of weight of
fused potash and soda, 118, 120, 223
—On the power of air in conducting
heat, 263
Bichat, M. 319
Biot, M. 77
Blanchard, Rev. J. his table of the rain

in various places in 18l«, 134
Bournon, count, on allanite, 49 — On

sodalite, 286
Bostock, Dr. observations on his revie\#-
of the atomic principles of che-
mistry, 143 — Errors in his quotations
from Mr. Dalton's book, 149
Bouvard, M. 75
Brain, its influence on the action of the

heart, 359— Experiments, 360
Brass, its combustion in oximuriatic

gas, 140
Bremner, Rev* James, his life boat, 86
The inventor of locks for cannon, 105
Brewster, Dr. his new instrument foir

measuring capillary att-^ction, 151
Brodie, Mt. B. C. his Croonkn lecture,

359
Brongniart, M. 1 56, 239
Bucholz, M. on alkaline metalloids, 189
C c Bud5,

INDEX.

Buds of pUiiisand treesj formation and

growth of, 1— Of fiwj iJ03
Burckhardt, M. 75

Cagniard'Latour^ M. bis improved fire
engine, 78, 175

Calomel, anafysis of, 228

Caloric, see Heat

Capillary attraction, ne\v instrument
for measuring, 15 1

Carnot, N. 175

Cedars, natural history of, 209, 297

Cements, >jee Mortars.

Cenis, mount, mineraloglcal descrip-
tion of, 310

Chabeaussiere, M. his instrument for
facilitating the reduction of plans,l79

Chaptal, M. 154 ,^

Charles, M. 175

Chemistry, atomic system of, 143

Chenevix, M. his analysis of potash,
126,224— On the quantity of oxigen
in muriatic acid, 129 — On oximu-
riatic and hyperoxirauriatic acid, 272

Chevreul, M. on the bitter principle,
and artificial tannin> 153

Children, J. G. esq. his experiments
on the combinations of boracic acid
with potash and soda, 119

Clarke, Dr. (of Nottingliam), his me-
teorological table, for that place,, in
the year 1810, 135

Cold, radiation and effects of, 217,263

Colours, ancient, found at Pompeia,
154

Conductors for lightnings faults in those
in general use, and method' of ob-
viating, 307

Cook, Mr. B. on the prevention of da-
mage by lightning, 305

Cordage, we Thread.

Cordier, M. on the mineralogy of mount
Mezin, 310— On the alum mines of
Aubin, 352

Correa, M. on the germination of the
water lily, 237

Corrosive sublinUte^ analjrsis of, 228

Cotton, substitute for, 161,278

Crane, William, esq. on the hyper*
oximuriate of soda, in answer to the
queries proposed by F. D. in the*
Journal for April last, 44

Crocodile, respirations of the shai^
nosed of America, 240

Crops, rotations of, 314

Croonian: tectui'e, on some physiolo-
gical researches, respecting the in-
ftuerKfr of the brain on the action of
the heart, and on the generation oi^
animal heat, 359

Cubiere, M. 315

Cuthbertson, J» esq. oil the voltaic
battery, 29

Cuvier, M. on fbssile animals, 154— Oa'
amphibious mammaliae, 238 — On th»

, feline genus, 239

Cypress firs, description of, 207

D.

Dalton Mr. on the scale of the baro^'
meter, 105— -On the nature of potash^
and soda, 120— Observations on his
opinions, 121, 124— On potassium^
sodium, &c. 129— On the' atomic
principles of chemistry, 14t3

D'Arcet, M. on the decomposition and
loss of weight of the alkalis, 118

Davis, Mr. J, his method of assisting
the escape of persons and the re-
moval of property from houses on-
fire, 321

Davy, Mr. E. on the hyperoximuriatfe
of potash, 126

Davy, Dr. H. on some of the combina-
tions of oximuriatic gas and oxigen,
and on the chemical relations of these
principles to inflammable bodies, 1 12,
222, 268— On the nomenclature of
the oximuriatic compounds, 233, 274

Davy, Mr. J. on the nature of potas-
sium and sodium, in answer to Mr,
Murray, 35— On the nature of oxi-
muriatic gas, in answer to the same,
39, 235— Mr. Murray's reply, 187

Daubuisson, M. his account of a pri-
toitive

INDEX.

mltive gypsum, sg^—Description of
his new invented sailing vessel, 820
■Dwandollc, M. on marine plants, 159

Decomposition of bodies by galvanism,
how effected, 27— Of acids and al-
kalis, prize question on, 152-^Of
certain substances by heat, 382

Delambre, M. his analysis of the pro-
ceedings of the mathematical and
physical class of the French Na-
tional Institute,, for 18C9, 72

Delaroche, M. on ichthyology, 240

Delisle, M. on the poise n of the « pas,
314

Detrey, M. son. his manufacture of
thread stockings, 319

piamond, capable of decomposing
water, at a very high temperature, 79
-—New crystalline form of, 1 55

Pisoxidation of oxide and oxidule ,of
iron, experimeitts on, 371

pittany, bastard, experiments on, in
proof of the opinion that its flowers
emit an inflammable gas, 66

pum6ril, M. on the sense of smell in

fishes, 344

E.

flarth, its rotation, &c. 72«-Perhaps
subject to irregularities, 73 — Its
figure, n

Jldgeworth, L. esq. on a new method
of roofing buildings with flag-stones,
81__His mode of securing memorials
for the informatioji of posterity, 85

j;dinburgh, Royal Society of, its pro-
ceedings, 151.*7rRoyal Medical So-
ciety of, prize question by, 152

Edmonston, Dr. 236

plectrical energies, how fa* they piay
be identified ^\^\v chemical affinities,
12

Electro-chesiiical inquiries, 78

Emery, 9. s^bstitute for, 155

Engine, on a new principle, descrip-
tion of, 175— Its application, 173 —
for extracting foul air, 330

Ether, its combustion in oxiraurialic
gas, 140

Evaporation, ecoRomical pftocesS ft>r,
without heat, wrongly ascribed to ftL
De Montgolfier, 1S8

F.
F. D. Answer to his queries relative ta

the hyperoximuriate of potash, 44

•Fettstein, apparently the same with

Swedish' natrolite, 287*-Constituent«

of, 288

Filtration of *vater, new method of, 324

Firo en^jine improved, by an inverse

application of Archimedes* screw, 78

Fire escape, anew, description of, 321

Firs, natural history and arrangement

of, 202, 295
Fishes, respiration of, 312' — Question
whether they possess the faculty of
smelling, 344
Flax, substitutes for, 161,278
Forcing-house for griipes on a new con-
struction, 109
Forster, T. esq.^n Mr, Howard's theory
of rain, 142.r-On an occasional in-
crease and decrease of the bulk qf the
hair of the head, 303
Forsyth's method of reanimating ol4

trees, 5
Fossile animals, geological observations

drawn from, 153
Fraicinella, said to evolve hidrogen gas,
66*— Experiments in proof, 67

G.

Galvanic decomposition, 23, 11€— In-
quiry concerning the ratio of the
power of igniting wires to the num-
ber of plates, 29— Anomalies in Dr.
Davy's experiments, i6.— New expe-
riments by Messrs. Singer and Cuth-
bertson, 31

Gardening, new practice of, with re-
spect to the management of trees, 5

Gas, evolved from the mixture of sand
withhme, 181

Gas, hidrogen, experiments on its
disoxidating oxide of iron, 370

Gas, oxigen, its combinations with the

metals from the fixed alkalis, &C.113,

Ce2 2C2

INDEX.

122 — Qnantity of, in oximuriatic
acid, 129 — Its combinations with oxi-
muriatic gas, 268

Gas, oximuriatic, its nature, formation,
and "various experiments on, 39, 1 12,
133, 222, 268

Gasses injected into the blood vessels of
animals, 314

Gauthey, M. his mode of estimating the
force of a stream, 69

Gay-Lussac and Thenard, Messrs. on
the peroxides of potash and soda, 36
38, 11 5-— On Mr. Davy's three papers
relative to the metals of the alkalis,
59— On the dip of the magnetic
Xjeedle, 77— On the combinations of
gaseous substances with each other,
and the compounds of nitrogen, 79 —
On the absorption of oxigen liy pot-
ash and barytes, when heated, 115,
118, 224 — On the quantity of hi-
drogen and ammonia contained in the
amalgam of ammonia, 880- On the
decomposition of some vegetable or
animal substances subjected to the
action of heat, 382

Geoffroy, M. on the classification of
apes, 239 — On two birds hitherto im-
perfectly known, 239 — On tortoises,
id.

Gordon, Dr. on the qualities of sound,
236

Grape house, method of constructing,
109

Grasses, their fructification, 158— Ger-
mijiation of, 238

Gr6goire, M. on an ancient bell of very
loud tone, 315

Guyton de Morveau, M. 79, 155

Gypsum, primitive, a stratum of, 202—
Other strata, 310
H.

Hair of the head, occasional increase
and decrease of the bulk of, 303

Hall, Rev. James his substitute for
hemp, prepared from bean stalks, 278

Hall, sir J. his experiments on beat
modified by compression, 151

Hall, M. esq. on the nature of heat,

215, 257

Harlem, Royal Society of, its proceed-
ings, 3 15--Prize questions, 316

Harrows, expanding, for cleaning land,
302

Hassenfra^z, M. on the disoxidation of
oxide of iron by hidrogen gas, 370

Heart, motion of the, how far «i-
fluenced by the brain, 359

Heat, animal, experiments on, 366

Heat, nature of, 215, 257 — Its sources,

216, 259-rIts motion, 217, 260^
Effects, 218, 264— Capacity, 220,
266— Vibiation, 258

Hemp, substitute for, 161,278

Henly, Mr. on electric conductors, SQ7

Herschell, Dr. his experiments on the
transmission of sunbeams through
transparent mediums, 2G0

Higgins, Mr. W. his hypothesis of the
composition of water, and on the cori-
stitution of sulphuretted hidrogen,124

Horn silver, analysis of, 225

Horsburgh, J. esq. notice of his India
Maritime Director j/, 152

Horses, how to relieve w^hen fallen dowu
in the shafts of loaded carts, 326

Howard, Mr. illustration of his theory
of rain, 142

Humboldt, M. Von, on the respiration
of crocodiles;, 240— And of fishes, 312

Hutton, Mr. J. jun. his improved reap-
ing hook, for corn, 171

Huttonian theory of volcanoes, 15^

Hydrophobia, prize essays on, 320
I.

Ibbetson, Mrs. on the interior of plants,
1— On Forsyth's method of reanimat-
ing old trees, 5 — On the fir tribe, and
its arrangement, 202, 295— On the
motion of barberry flowers, 213

Iceland, geological remarks on, 151

Ichthyology, recent researches in, 240

Imaginary quantities, defective algo-
rithm of, 254

Implement for extirpating flocks ai(id
thistles, 301 ^

Imrie,

INDEX.

Xmrie, col. 47

Ink, vegetable, that cannot be oblite-
rated, 154, S20, 343

— — , various methods of restoring the
traces of, when obiiteratcd, 339

, improvements in the. manufac-
ture of, 341

Inscriptions on tiles, deposited under
public buildings, for the information
of posterity, 85

Instrument for reducing or enlarging
plans, 179

Iron mine of Cogne, supposed to be the
richest in the world, 293

Iron water pipes, on the use of, and
mode of securing tlieir joints, 136

J.

Jacksonian premiums, distribution of,
320.

Jameson, Professor, on the possible ex-
istence of coal in the depositions of
red sand stone in Scotland, ld2— On
tho Iceland crystal, 236

JefFery, Mr. Wm. his expanding har-
rows, for cleansing foul land, and
harrowing in seeds, 302

J. M. answer to, 159

Jussieu, his new order of plants, 158

Justus, reply to his remarks on potas-
sium, sodium, &c. 129.

K.

Klaproth, Dr. his examination of . na-
trolite, 286

Knight, T. A. Esq. on the term of life
and strength of a plant, 5. — His forc-
ing house for grapes; and best me-
thod of constructing them for other
fruits, 109— His improved method of
cultivating the Alpine strawberry,
2l4«— His account of a mule between
the ass and female zebra, 127

^ L.

^ablUardipje, M. on a new plant of the

palm kind, 158
]Lagrange, M. on the stability of the

planetary system, 72

Lamouroux, M. on marine plants, 139

Laplace, M. on the motion of the moon,

75— His coefficient for barometrical

measurements preferable in some

cases to that of Ramond, 77.

Larches, description of, 209.— Fructi-
fication of, 297

Leach, Mr. W. E. on the arrangement
of the diptera tribe, 152

Leblanc, M. o« the domestication of
the vicugna of America, 315

Lee, H. P. Esq. bis newly invemel
thrashing machine, 274

Lcgendre, M. his new theorems a«
fluxions, 75

Leslie, Mr. on the transmission of Beat,
solar and culinary, through transpa-
rent mediums, 260

Light, propagation of, 78

Lightning, proposition for the preven-
tion of damage by, C05

Life boat, made of a common ship's
boat, 86.

Lime, cohesion of, with mineral, ve-
getable, and animal substances, 18 1

Lily, water, germination of, 237

L. O. C. on the scale of the barometer,
105— On the construction of an air
pump for procuring a perfect va-
cuum, 107

Lunar tables, 75

Lyall, Mr. R. the sensible perspiration
of the diclamnus albus, 66

Lydiatt, Mr. E. on the different force*
with which tubes, bars, and cylin*
ders, adhere to a magnet, 34.
M.

Mackenzie, Sir G. on the rocks of Ice-
land, 151

Magendie, M. on the poison of the
upas, 314

Magnetism, its effects on tubes, bars,
&c. 34

Mariotte's experiment on the current
of the Seine, found to be correct, 71

Mathematicus on the defective algo-
rithm of imaginary quantities, 254

Mathieu,M.ou the figure of the Earth, 77
Mayo ock.

INDEX.

iSIaycock, Dr. on the hypothesis which
refers chemical affinity to the ekc-
trical energies of the particles of mat-
ter, 12— On the transmission of heat
through a transparent medium, 260

Meerten, M. Van, on the combustion
of ether, metals, camphor, and essen-
tial oils in oxi muriatic gas, 140

^letals from the fixed alkalis, their
combinations -with o:cimviri?itic gas
and oxi gen, 113, 183

Mrtals, common, their combinations
with oximuriatic gas, 225

l^Ietals of the earths, action of oxigen
and oximuriatic gas on, 222

Jleteorological Journal, for April, 80t—
May, 160

Meteorological table for Nottingham,
during the year 1810, 135

BIczin, mount, mineralogical descrip-
tion of, 310.

Mirbel, M, on the physiology of
plants, 236

Jtfichelotti, his process for ascertaining
the velocity and strength of a current
of water, 69

f^icrometers, applied to the barometer,
78

UTontgoIfier, M. 175

Moon, motion of the, 75

3»'Ioore, W. esq. on the motion of rockets,
both in nonresisting, and resisting
mediums, 242 — Remarks on his the-
ory, 384

Mortars and cements, 154— Cohesion
which lime contracts with mineral,
vegetable, or animal substances, 181

Motion of rockets, theory of, 241

Moult, Mr. W. his new method of
using the filtering stone, 324

Mule, between the ass and zebra, 127

Muriates of the metals of the earths,
experiments on, 222

Murray, Mr., Answer to his observa-
tions on the nature of potassium and
sodium, 35 — Reply to his strictures
on Dr. H. Davy's theory respecting
«itimuriatic gas, 39— Observations on

his paper on oxigen contained in
that gas, 235— His defence of his
strictures on Dr. Dayy^'s theory, 187

N.

National Institute of France, proceed-
ings in, 72, 153, 175,236, 312 '

Natrolite of Klaproth, distinct from the
sodalite of Dr. Thomson^ 286

-, Swedish, .apparently the sam«

with the fettstein of Werner, 287

Nauche, M. on the contraction of the
muscles, 319.

Needle, magnetic, observatiQns on the
dip of, 77 ;

Nettles, fibres of, a substitute for flax^
hemp, tow, and cotton, 161

Nightshade, experiments with th^
juice of, 314

Nomenclature of the oximuriatic com-
pounds, reflections on, 233

Nysten, Dr. on the effect of gasses in«
jected into the blood vessels of a^-
.nials, 314

Onion, vegetation and growth of the^^
236

Ornithology, recent discoveries in, 239

Oxidation and disoxidation, experi-
ments on, 371

Oxides, metallic, how affected by th«
action of oximuriatic gas, 227,371

Oxides of soda and potash^ 28

F.

Pakali, Baron, on the velocity of the
Danube, 71

Palissot-Beauvois, M. xjn the fructifica-
tion of grasses, 158

Paris, academical society of sciences,
and society of encouragement at, their
proceedings, 319

Percy, M. on wine coolers used in
Spain, 315

Peroxides of the alkalis, treated with
acids, 38

Pine

INDEX.

Tine stove, improvement in the con-
struction of, 111

Pinus balsamea, description of, 208

Planetary system, question relative to
its stabUity, 72, 75

Plans, instrument for reducing, or en-
larging, 179

Plants interior structure of, and growth
of their buds, 1— Cause of death in,
' 6— Natural affinity of, 11— Source of
their nutriment, 236

Playfair, professor, his illustration of the
Huttonian theory of volcanoes, 151

Pneumatics, experiments in, 107

Poisons, experiments on, 314

Poisson, M. on the variations of the
elements, of the planets, and on the
rotation of the earth, 72

Poiteau, M» on grasses, 258

Potash, hyperojdmuriate of, its forma-
tion, 126

Potassium and sodium, various experi-
ments on, 35, 62, 113, 132, 223

Poyfire De Cer6, M. on the mode of
■washing wool, 315

Price, Mr. J. T. on the use of iron
pipes for conveying water, and mode
of seeming their joints, 135

Prize questions, 316

Prwiy, M. De, on barometrical meji-
surements of inconsiderable heights,
77— On the invention of a new en-
gine, 175

Proven9al, M. on respiraAion^ 315

R.

Rain, illustration of Mr. Howard^s theo-
ry of, 142

Rain table for the year 1810, 134

Ramond, M. his coefficient for barome-
trical measurements, too great foe in-
considerable heights, 77

Reaping hook improved, 171

Regnier, M. his rheumameter, to esti-
mate and compare the velocity of the
current of rivers, 68

Repulsion, *ee Attraction

Respiration, experiments on» 2^12, 366

Rheumameter,description and U9e of,6*

Richerand, Professor, on the cofntrac*
tion of the muscles, 319

Risseau, M. on Ichthyology, • 240.

Ritter, M. on the electrical decompop
sition of potash and soda, 116

Rivers, instrument for measuring the
velocity and force of, 68

Rockets, military, their motion in non-
resisting and resisting mediums, 24 1

Roofs of flag-stones, method of mak-
ing, 81

Rumford, Count, distribution of hi*
prize medals, 319

S.

Sage, M. 79— On the best process for
making solid inortar, or stucco, 181—
On a substitute for emery, 155 — On
some petrified fruits^ 158 — On the
means of remedying the stings of in-
sect^ and fishes, 314
St. Amand, M. his claim to the inven-
tion of the economical process for
evaporation, 138
Sap of trees, circulation of, 5, It
Saussure, M. on the mineralogy of

Mount Cenis, 311
Sauviac, M. on artificial turquoises, 154
Scaffolding for working on a high roo^

construction of, 83
Scheele on the bleaching powers of the-

oximuriatic gas, 234
Scientific news, 72^, 151, 236, 312
Scotch firs, natural history of, 205
Screw-zuljusting plough, 298
Ship on a new construction, 320
Ship's boat, method of converting oafr

into a life boat, 86
Singer, G. J. Esq. on the igniting, or
■wire-melting power of the voltaic,
battery, as proportioned to the num-
ber of plates eDftpIoyed, 29
Smell, sense of, in fishes, question on

the existence of, 344
Smith, Mr. B. his method of raising a
loaded cart, when the shaft horse i»
fallen, 326

Smitb»

INDEX.

Stnith, Mr. E. on ilic manufacturing of
threacl, and articles resembling flax,
hemp, tow, and cotton, from the
fibres of the common nettle, l6l

Sodalite, a new mineral, 2S5

Sodi-sm and potassium, natureof, 35, 38

Sounds, qualities of, 236

Stahl's near discovery of the pure alka-
lis, 117

Stings of insects and fishes^ means of
curing, 314

Stratingh, M. on the combustion of
ether, metals, &c. in oximuriatic
gas, 140

Strawberries, improved method of cul-
tivating, 214

Sweiger, M. on tortoises, 240
T.

Tarry, Dr. H. on the processes employ-
ed to cause writing to disappear from
paper, to detect the writing that has
been substituted, and to revive that
which has been made to disappear,
339— His improvement of common
ink, 341— Notice of a new ink, that
resists the action of chemical agents,
154, 343

Taylor, Mr. J. his method of ventilat-
ing mines and hospitals, by extract-
ing foul air from them, 330

Tlienard, M. see Gay-Lussac.

Theory and Hypothesisy Remarks on the
meaning of the terms, and their dif-
ference, 144

Thompson, Mr. James, his analysis of
the sulphate of harytes, 225

Thomson, Dr. Thomas, on allaaite, 47
—On sodalite, 285

Thistles, description of an implement
for destroying, 301

Thrashing machine, an improvement
in, described, 274

Thread manufactured from the fibres of
common nettles, 161 — From those of
the bean stalk, 278

Tin, its combustion in oximuriatic gas,
140

Tobacco, analysis of, 153 — PeouBaf

principle in, 153
Tortoises, new species of, 239
Tow, made of the fibres of nettles, 161

— Of the fibres of bean stalks, 278
Trees, buds of, their formation and

growth, 1.— Cause of death in, 6—

Various juices of,8, 12— Fir tribe, 202
Turquoises, artificial, 154

Vauquclln, his analysis of tobaccos
and belladonna, 153— On the de-
leterious effects of the juice of dead-
ly nightshade, 514— On the analys>is
of an ancient bell, 315
Ventilation of mines and hospitals, 330
Vines, see Grape house.— Composition

to stop the bleeding of. 111
Volcanoes, extinct, in France, 311
Voltaic battery, ratio of its power of ig-
niting wires, 81

U.

Upas, poison of, experiments on, 314

W.

Water decomposed by the diamond, 79

Water pipes of iron, 136

Wernerian Natural History Society^

proceedings at its sessions, 152, 235
Wilkinson,Dr. on the ratio of the p©wer

of ignition in the voltaic battery, SO
Wine, distillation of, 154
W. N. on conductors for lightning, 309
Wollaston, Dr. his experiments on al-

lanite, 48, 55— On sodalite, 286 — His

Swedish natrolite probably the sam«

as Werner's fettstein, 287

Yvart, M. on the means of improving

agriculture by rotations of green

crops, 314

Z.
Zebra, offspring of, by a male ass, de«

scribed, 127
Zeno, on Mr. Moore's paper on the mo'

tion of Rockets, 384

END OF THE TWENTY- NINTH VOLUME,

Stratford, Frmter, Crown Court, Temple bar.